CN102527241A - Gas separation membrane assembly and gas separation method - Google Patents

Abstract

The prevent invention provides a method for preparing nitrogen-rich gas through supplying high-temperature gas with a temperature above 150 DEG C to a gas separation membrane assembly.

Description

Gas separation membrane module and gas separation method

technical field

The invention of the present application relates to a gas separation membrane module and a gas separation method for gas separation using a plurality of hollow fiber membranes with selective permeability.

Background technique

As a separation membrane module for gas separation (such as oxygen separation, nitrogen separation, hydrogen separation, water vapor separation, carbon dioxide separation, organic vapor separation, etc.) using a separation membrane with selective permeability, there are plate type, frame type, and tube type , hollow wire type, etc. Among them, the hollow fiber type gas separation membrane module not only has the largest membrane area per unit volume, but also has excellent pressure resistance and self-supporting properties, so it is industrially advantageous and can be widely used.

Contents of the invention

The invention of the present application is described in detail in the following sections A to G, and includes inventions in which two or more of the inventions described in each section are combined. The background art and problems related to the invention disclosed in each section are described in each section.

Description of drawings

Fig. 1 represents the measurement result of the embodiment 1 of part A and comparative example 2;

Fig. 2 represents the measurement result of embodiment 1 and embodiment 2 of part A;

Fig. 3 is a schematic diagram showing an example of a gas separation membrane module;

Fig. 4 is a schematic diagram showing a method of manufacturing a tube sheet for separation of mixed gases;

5 is a cross-sectional view schematically showing the basic configuration of the separation membrane module according to the first embodiment of Part C;

Among Fig. 6, Fig. 6 (a) represents an example of the structure of component end, and Fig. 6 (b) represents the structure of existing type;

Fig. 7 is a diagram showing other structures around the tube sheet;

Fig. 8 shows an example of the structure of the assembly end portion of the second embodiment of part C, Fig. 8 (a) shows the state at room temperature, and Fig. 8 (b) shows the state at high temperature;

Fig. 9 shows an example of the structure of the module end of the third embodiment of part C;

FIG. 10 is a diagram showing an example of another embodiment;

Fig. 11(a) in Fig. 11 is a sectional view showing yet another example of the separation membrane module, and Fig. 11(b) is an enlarged view of a part of Fig. 11(a);

FIG. 12 is a diagram showing an example of an arrangement of O rings;

Fig. 13 is a cross-sectional view of a gas separation membrane module according to one mode of part D;

Fig. 14 is a cross-sectional view of the tubular member of the assembly of Fig. 13;

Fig. 15 is a front view and a side sectional view of the cap member of the assembly of Fig. 13, and Fig. 15(A) is a sectional view along the X-X line of Fig. 15(B);

Fig. 16 is a schematic diagram of a cap member showing an example in which the number of fixing rods is changed;

Fig. 17 is a cross-sectional view schematically showing the basic configuration of a gas separation membrane module according to one mode of part E;

Figure 18 is a partially enlarged view of Figure 17;

Fig. 19 is a sectional view showing an example of a box in the assembly of Fig. 17;

20 is a cross-sectional view schematically showing the basic configuration of a gas separation membrane module of one embodiment of Part F;

Fig. 21 (A) is a partial enlarged view of Fig. 20, and (B) is an enlarged view further showing a part thereof;

Fig. 22(A) is a sectional view showing a gas separation membrane module in another embodiment, and (B) is a partially enlarged view;

Fig. 23 is a cross-sectional view showing a gas separation membrane module of another embodiment;

24 is a cross-sectional view showing a gas separation membrane module according to another embodiment;

Fig. 25 is a cross-sectional view schematically showing the basic configuration of a gas separation membrane module according to one embodiment of part G.

FIG. 26 is an enlarged view of a part of FIG. 25 .

FIG. 27 is a sectional view in A-A of FIG. 26 .

Symbol Description

1, 1', 101 separation membrane module

10, 110, 110' cylindrical container

10a Inner peripheral surface of container

10f Flange

10h opening

10s steps

10t steps

110g slot

111 pipe

112 end member

12, 112h through the gas outlet

112f Flange

14 hollow fiber membrane

15, 115 Hollow tow

17 ring seal member

18, 118, 119 O-rings

20, 21, 26, 27, 120, 121, 127 caps

20h opening

120f Flange

120s steps

22A Mixed gas inlet

22B Non-permeable gas outlet

27f Flange

127f Flange

127g slot

30, 30’, 38, 130A, 130B, 530 tube sheets

30s, 530s steps

30’t steps

41 discharge pipe

42 set screw

43 Fixtures

201 Gas separation membrane module

210 boxes

211 Cylindrical container

212 opening

214 hollow fiber membrane

215 hollow tow

217, 218 inner peripheral groove

219 peripheral groove

220, 221 Cap member

220A end face

220B Cylindrical part

220f flat part

220g flat portion

220h through hole

223 outlet

227a, 227b inner peripheral groove

230, 231 tube sheet

R1, R2 elastic ring members

245 fixed rod

246 Nut

P1 Gas inlet

P2 Non-permeable gas outlet

P3 gas flow path

601 Gas separation membrane module

610 cabinet

610a Mixed gas inlet

610b Non-permeated gas outlet

610c through gas outlet

611 tubular member

612, 613 Caps

614 hollow fiber membrane

615 hollow tow

618 Sealed space

619a Mixed gas space

619b Non-permeable gas spaces

621, 622 tube sheet

631 Membrane components

631a, 631b ends

801 Gas Separation Membrane Module

810, 910 cabinet

810a, 910a Mixed gas inlet

810b, 910b Non-permeated gas outlet

810c, 910c through gas outlet

910d purge gas inlet

811 tubular member

813 tube sheet retaining member

813a Straight line

813b Large diameter part

813c taper

814, 914 hollow fiber membrane

815, 915 hollow tow

818, 918 sealed space

819a Mixed gas space

819b Non-permeable gas spaces

821, 822, 921, 922 tube sheets

822a Hollow fiber membrane embedding part

822b tube sheet clean part

831 Membrane components

831a, 831b ends

850, 950 sealed structure

851, 853 sealing tape

855 Fixing Tape

857 Fixtures

891, 893 Filling materials

971 core tube

971a hole

A1 exposed part

A31 Clearance

1001 Gas separation membrane module

1010 cabinet

1010a Mixed gas inlet

1010b Non-permeated gas outlet

1010c through the gas outlet

1011 Cylindrical member

1011a, 1011b thick wall part

1011d recessed part

1012 cap member

1014 hollow fiber membrane

1015 hollow tow

1018 Sealed Space

1019a Mixed gas space

1019b Non-permeable gas spaces

1021, 1022 tube sheet

1021s class department

1060 sealing member

C1 ring groove

B11 Mixed gas inlet

B12 through the gas outlet

B13 Non-permeable gas outlet

B14 hollow fiber membrane

B15 cabinet

B16a, 16b tube sheet

B21 mold

B22 cabinet

B23 tube sheet

B24 hollow fiber membrane

Detailed ways

Next, Part A to Part G will be described regarding embodiments of the present invention.

[Part A: Method for producing nitrogen-enriched air from high-temperature gas]

(Background technique)

For aircraft, there is a method of using an on board inert gas generating system (OBIGGS: on board inert gas generating system) as one of the explosion protection methods for fuel tanks. In order to prevent the risk of explosion, the oxygen concentration in the gas phase region inside the fuel tank needs to be lower than a prescribed concentration. Therefore, OBIGGS separates oxygen from air to produce nitrogen-enriched air with high nitrogen concentration, and supplies it to fuel tanks.

OBIGGS, for example, utilizes air separation membrane modules to produce nitrogen-enriched air. Regarding the air separation membrane, since the higher the pressure and temperature of the gas to be supplied, the processing capacity will generally increase. Therefore, the extracted gas from the engine or the surrounding air is compressed by a compressor or the like and supplied to the air separation membrane module. The compressed gas is usually 149 to 260°C.

Existing air separation membrane modules operate efficiently at about 82°C to about 93°C, and at such high temperatures as described above, the separation performance is remarkably degraded and thus unusable. Therefore, generally, the compressed gas is cooled to the temperature by using a heat exchanger or mixing with low-temperature air, and then supplied to an air separation membrane module (JP-A-2010-142801).

(Problem to be solved by the invention of Part A)

The object of the invention of Part A is to provide a method for producing nitrogen-enriched air by supplying high-temperature compressed air of 150° C. or higher to an air separation membrane module.

The main points of the invention disclosed in this section are as follows.

1. A method for producing nitrogen-enriched air from air using an air separation membrane module, characterized in that,

Air above 150°C is supplied to the air separation membrane module.

(Effects of the Invention of Part A)

According to the method of the invention of Part A, air at a high temperature, eg, 150°C or higher, can be supplied to the air separation membrane module to obtain nitrogen-enriched air with increased nitrogen concentration. The invention of this part is characterized by the use of an air separation membrane that has a high oxygen permeation rate and oxygen and nitrogen separation performance at high temperatures, and can maintain its performance even when used at a high temperature for a long time. The invention in this section is suitable, for example, for an explosion-proof system for fuel tanks of aircraft. When the invention of this section is used in the explosion-proof system, the heat exchanger and the like for cooling high-temperature air when supplying air to the air separation membrane module can be reduced in weight. In addition, for air separation membranes, the higher the temperature of the supplied air, the faster the permeation rate. Therefore, according to the method of the invention of this section, which can handle high-temperature air, the membrane area can also be effectively reduced. Therefore, it is possible to simplify and reduce the weight of the equipment in the aircraft.

(implementation in part A)

The invention disclosed in this section is a method for generating nitrogen-enriched air from air using an air separation membrane module, characterized in that high-temperature air of 150° C. or higher is supplied to the air separation membrane module. In this section, unless otherwise specified, "high temperature" means 150°C or higher, preferably 175°C or higher, more preferably 200°C or higher.

An air separation membrane module can be obtained, for example, by bundling about 100 to 1,000,000 hollow fiber membranes of appropriate length, keeping at least one end of the hollow fiber in an open state, and fixing the hollow fiber with a tube sheet made of thermosetting resin or the like. At both ends of the bundle, in a container provided with at least an air supply port, a permeable gas discharge port, and a non-permeable gas discharge port, the hollow fiber membrane elements composed of the obtained hollow fiber bundles and tube sheets are accommodated and installed so that The space leading to the inside of the hollow fiber membrane is isolated from the space leading to the outside of the hollow fiber membrane, thereby obtaining. In such an air separation membrane module, air is supplied from the air supply port to the space in contact with the inside or outside of the hollow fiber membrane, and oxygen in the air selectively permeates the membrane while flowing in contact with the hollow fiber membrane. The permeated gas (oxygen-enriched air) is discharged from the permeated gas discharge port, and the non-permeated gas (nitrogen-enriched air) that has not permeated the membrane is discharged from the non-permeated gas discharge port, thereby performing gas separation.

The air separation membrane is not particularly limited, and examples include an extremely thin dense layer (preferably 0.001 to 5 μm in thickness) mainly responsible for air separation performance and a relatively thick porous layer (preferably 0.001 μm in thickness) supporting the dense layer. 10 ~ 2000μm) asymmetric structure of the asymmetric air separation membrane. A hollow fiber membrane having an inner diameter of 10 to 3000 μm and an outer diameter of about 30 to 7000 μm is preferable.

The air separation membrane preferably has the characteristics described below at high temperature.

The air separation membrane preferably has a high oxygen permeation rate at high temperature. For example, the oxygen transmission rate (P' _O2 ) at 175°C is 20×10 ^-5 cm ³ (STP)/cm ² ·sec·cmHg or more, preferably 25×10 ^-5 cm ³ (STP)/cm ² ·sec·cmHg or more, more preferably 30×10 ^-5 cm ³ (STP)/cm ² ·sec·cmHg or more. Furthermore, the air separation membrane preferably has high separation performance even at high temperatures. For example, at 175° C., the ratio (P' _O2 /P' N2 ) of the oxygen permeation rate and the nitrogen permeation rate (P' O2 /P' _N2 ), which shows the separation performance of the membrane, is 1.8. or more, preferably 2.0 or more, more preferably 2.5 or more. It should be noted that the ratio of the transmission rates generally takes a larger value at low temperatures. When the permeation rate ratio, that is, the separation performance is high, the recovery rate of the target nitrogen-enriched air increases.

In addition, it is preferable that the air separation membrane does not greatly reduce the oxygen permeation rate and the separation performance of the membrane even if it is used at high temperature for a long time. For example, when used at 175°C for 140 hours, the oxygen transmission rate (P' _O2 ) and the ratio of the oxygen transmission rate to the nitrogen transmission rate (P' _O2 /P' _N2 ) are preferably P before use. Each of ' _O2 and _P'O2 / _P'N2 is 75% or more, More preferably, it is 80% or more, More preferably, it is 90% or more.

Furthermore, the air separation membrane preferably maintains its shape to such an extent that its function is not impaired even in a high-temperature state. For example, the glass transition temperature (Tg) of the material constituting the air separation membrane is preferably higher than 225°C (that is, it does not show below 225°C), more preferably 250°C or higher, and even more preferably 300°C or higher (including the glass transition temperature cannot be determined). Furthermore, it is preferable to keep the shape at a high temperature for a long time, and the shape retention rate when left at 175° C. for 2 hours is preferably 95% or more, more preferably 99% or more. Here, in this section, the term "shape retention" means the ratio of dividing the length of the filament after heat treatment at 175° C. for 2 hours by the original length before heat treatment.

Preferred materials for separation membranes with a glass transition temperature higher than 225° C. include polyimide, polyethersulfone, polyamide, polyetheretherketone, and the like, and particularly preferably polyimide.

The material for forming the asymmetric gas separation hollow fiber membrane (hereinafter also simply referred to as the hollow fiber membrane) is not particularly limited, but an example of the composition of polyimide that is preferably used as an air separation membrane and has a glass transition temperature higher than 225°C Be explained. The polyimide of the following composition is an aromatic polyimide represented by the repeating unit of the following general formula (1), and the glass transition temperature is usually 250° C. or higher, preferably 300° C. or higher (including the glass transition temperature that cannot case of measurement).

[chemical 1]

通式(1)

Formula (1)

In the above formula, B is a tetravalent unit derived from a tetracarboxylic acid component, and A is a divalent unit derived from a diamine component. Hereinafter, the units constituting the aromatic polyimide will be described in detail.

Unit B is a tetravalent unit derived from a tetracarboxylic acid component, and contains 10 to 70 mol%, preferably 20 to 60 mol%, of units B1 having a diphenylhexafluoropropane structure represented by the following general formula (B1) and 90 -30 mol%, preferably 80 to 40 mol%, of unit B2 having a biphenyl structure represented by the following general formula (B2), preferably substantially has unit B1 and unit B2. When the diphenylhexafluoropropane structure is less than 10 mol % and the biphenyl structure exceeds 90 mol %, the gas separation performance of the obtained polyimide decreases, making it difficult to obtain a high-performance gas separation membrane. On the other hand, when the diphenylhexafluoropropane structure exceeds 70 mol% and the biphenyl structure is less than 30 mol%, the mechanical strength of the polyimide obtained may fall.

In addition, the unit B may contain a tetravalent unit based on a phenyl structure represented by the following formula (B3). The tetravalent unit based on the phenyl structure represented by the formula (B3) is 0 to 30 mol%, preferably 10 to 20 mol%.

Furthermore, the unit B may contain the tetravalent unit B4 originating in other tetracarboxylic acid other than the unit B1, B2, B3.

[Chem 2]

The unit A is a divalent unit derived from a diamine component, and includes a unit A1 selected from the group consisting of the following general formulas (A1a), (A1b) and (A1c) and a unit selected from the group consisting of the following general formulas (A2a) and (A2b) selected cell A2 in the group. Furthermore, unit A may contain the divalent unit A3 originating in another diamine component other than unit A1, A2.

Unit A1a is a divalent unit based on a biphenyl structure represented by formula (A1a), and units A1b and A1c contain hexafluoro-substituted structures represented by formula (A1b) and formula (A1c), and more specifically, have two The structural unit of trifluoromethyl.

[Chem 3]

(In the formula, X is a chlorine atom or a bromine atom, and n is 1 to 3.)

[chemical 4]

(In the formula, r is 0 or 1, and the phenyl ring may be substituted by an OH group.)

[chemical 5]

(In the formula, Y represents O or a single bond.)

When unit A1 has the unit represented by formula (A1a), it is 30-70 mol% in unit A, Preferably it is 30-60 mol%. The benzidines contribute to improvement of the degree of separation, but when the amount is too large, the polymer becomes insoluble and film formation is difficult, and when the amount is too small, the degree of separation decreases, which is not preferable.

When unit A1 has a unit represented by formula (A1b) and/or formula (A1c), these units are contained in unit A in an amount of 10 to 50 mol%, preferably 20 to 40 mol%.

The unit A2 is selected from a sulfur-containing heterocyclic ring structure, specifically, from the group consisting of units represented by the following general formulas (A2a) and (A2b).

[chemical 6]

(In the formula, R and R' are hydrogen atoms or organic groups, and n is 0, 1 or 2.)

[chemical 7]

(In the formula, R and R' are hydrogen atoms or organic groups, and X is -CH ₂ - or -CO-.)

Unit A2 is contained in unit A in an amount of 90 to 30 mol%, preferably 90 to 40 mol%, more preferably 90 to 50 mol%, further preferably 80 to 60 mol%.

The unit A3 is contained in the unit A in an amount of 50 mol % or less, preferably 40 mol % or less, more preferably 20 mol % or less.

Next, the monomer components of the above-mentioned units constituting the aromatic polyimide will be described.

The unit having a diphenylhexafluoropropane structure represented by the above general formula (B1) is obtained by using (hexafluoroisopropylidene) diphthalic acid, its dianhydride or its esterified product as a tetracarboxylic acid component . As the above-mentioned (hexafluoroisopropylidene) diphthalic acid, 4,4'-(hexafluoroisopropylidene)diphthalic acid, 3,3'-(hexafluoroisopropylene)diphthalic acid, base) diphthalic acid, 3,4'-(hexafluoroisopropylidene)diphthalic acid, their dianhydrides or their esters, but particularly preferred 4,4'-(hexafluoroisopropylidene)diphthalic acid Propyl) diphthalic acid, its dianhydride or its ester.

The unit having a biphenyl structure represented by the above general formula (B2) is obtained by using biphenyltetracarboxylic acids such as biphenyltetracarboxylic acid, its dianhydride, or an esterified product thereof as a tetracarboxylic acid component. As the above-mentioned biphenyltetracarboxylic acids, 3,3',4,4'-biphenyltetracarboxylic acid, 2,3,3',4'-biphenyltetracarboxylic acid, 2,2',3 , 3'-biphenyltetracarboxylic acids, their dianhydrides or their esterified products, but particularly preferred are 3,3',4,4'-biphenyltetracarboxylic acids, their dianhydrides or their esterified products.

The tetravalent unit based on the phenyl structure represented by the said general formula (B3) is obtained by using pyromellitic acid, such as pyromellitic acid and its anhydride. The pyromellitic acid is preferable in terms of improving mechanical properties, but if the amount is too large, it will cause coagulation of the polymer solution at the time of membrane formation, etc., making it unstable and making it difficult to form a hollow fiber.

The other tetracarboxylic acid component providing the unit B4 is a tetracarboxylic acid other than the above-mentioned compounds, and a compound that can further improve performance according to circumstances is selected without impairing the effects of the invention in this section. For example, diphenyl ether tetracarboxylic acids, benzophenone tetracarboxylic acids, diphenyl sulfone tetracarboxylic acids, naphthalene tetracarboxylic acids, diphenylmethane tetracarboxylic acids, diphenyl Propane tetracarboxylic acids, etc.

The divalent unit based on the biphenyl structure represented by the said general formula (A1a) is obtained by using the halogen-substituted benzidine represented by the general formula (A1a-M) as a diamine component.

[chemical 8]

(In the formula, X is a chlorine atom or a bromine atom, and n=1 to 3.)

Examples of halogen-substituted benzidines include dichlorobenzidines (diaminodichlorobiphenyls), tetrachlorobenzidines (diaminotetrachlorobiphenyls), hexachlorobenzidines, and tetrabromobenzidines. , dibromobenzidine, hexabromobenzidine, etc. Examples of the above-mentioned dichlorobenzidines include 3,3'-dichlorobenzidine (DCB), and examples of tetrachlorobenzidines include 2,2',5,5'-tetrachlorobenzidine (TCB )wait.

The divalent unit represented by the general formula (A1b) is obtained by using hexafluoro-substituted compounds represented by the general formula (A1b-M) as a diamine component.

[chemical 9]

(In the formula, r is 0 or 1, and the phenyl ring may be substituted by an OH group.)

Preferred compounds of the hexafluoro-substituted compounds represented by (A1b-M) are represented by general formulas (A1b-M1) to (A1b-M3).

[chemical 10]

Examples of bis[(aminophenoxy)phenyl]hexafluoropropanes represented by the general formula (A1b-M1) include 2,2-bis[4-(4-aminophenoxy)phenyl ]hexafluoropropane, 2,2-bis[4-(3-aminophenoxy)phenyl]hexafluoropropane. Examples of bis(aminophenyl)hexafluoropropanes represented by the general formula (A1b-M2) include 2,2-bis(4-aminophenyl)hexafluoropropane. Examples of the hydroxy-substituted bis(aminophenyl)hexafluoropropanes represented by the general formula (A1b-M3) include 2,2-bis(3-amino-4-hydroxy)hexafluoropropane.

Moreover, the divalent unit represented by General formula (A1c) is obtained by using the hexafluoro compound represented by General formula (A1c-M) as a diamine component.

[chemical 11]

(In the formula, Y represents O or a single bond.)

Examples of diamine compounds represented by the general formula (A1c-M) include 2,2'-bis(trifluoromethyl)-4,4'-diaminodiphenylether, 2,2' - Bis(trifluoromethyl)-4,4'-diaminobiphenyl and the like.

In addition, the unit having the structure represented by the above-mentioned general formula (A2a) or the above-mentioned general formula (A2b) is obtained by using an aromatic diamine represented by the following general formula (A2a-M) and general formula (A2b-M), respectively Available as a diamine component.

[chemical 12]

(In the formula, R and R' are hydrogen atoms or organic groups, and n is 0, 1 or 2.)

[chemical 13]

(In the formula, R and R' are hydrogen atoms or organic groups, and X is -CH ₂ - or -CO-.)

Examples of the aromatic diamine represented by the general formula (A2a-M) above include diaminodibenzos represented by the following general formula (A2a-M1) in which n is 0 in the general formula (A2a-M). Thiophenes or diaminodibenzothiophene=5,5-dioxides represented by the following general formula (A2a-M2) in which n is 2 in the general formula (A2a-M).

[chemical 14]

(In the formula, R and R' are hydrogen atoms or organic groups.)

[chemical 15]

(In the formula, R and R' are hydrogen atoms or organic groups.)

Examples of the diaminodibenzothiophenes (general formula (A2a-M1)) include 3,7-diamino-2,8-dimethyldibenzothiophene, 3,7-diamino- 2,6-Dimethyldibenzothiophene, 3,7-diamino-4,6-dimethyldibenzothiophene, 2,8-diamino-3,7-dimethyldibenzothiophene, 3,7-diamino-2,8-diethyldibenzothiophene, 3,7-diamino-2,6-diethyldibenzothiophene, 3,7-diamino-4,6-di Ethyl dibenzothiophene, 3,7-diamino-2,8-dipropyl dibenzothiophene, 3,7-diamino-2,6-dipropyl dibenzothiophene, 3,7-di Amino-4,6-dipropyldibenzothiophene, 3,7-diamino-2,8-dimethoxydibenzothiophene, 3,7-diamino-2,6-dimethoxydi Benzothiophene, 3,7-diamino-4,6-dimethoxydibenzothiophene and the like.

Examples of the diaminodibenzothiophene=5,5-dioxides (general formula (A2a-M2)) include 3,7-diamino-2,8-dimethyldibenzothiophene =5,5-dioxide, 3,7-diamino-2,6-dimethyldibenzothiophene =5,5-dioxide, 3,7-diamino-4,6-dimethyl Dibenzothiophene = 5,5-dioxide, 2,8-diamino-3,7-dimethyldibenzothiophene = 5,5-dioxide, 3,7-diamino-2,8 -Diethyldibenzothiophene=5,5-dioxide, 3,7-diamino-2,6-diethyldibenzothiophene=5,5-dioxide, 3,7-diamino -4,6-diethyldibenzothiophene=5,5-dioxide, 3,7-diamino-2,8-dipropyldibenzothiophene=5,5-dioxide, 3, 7-diamino-2,6-dipropyldibenzothiophene=5,5-dioxide, 3,7-diamino-4,6-dipropyldibenzothiophene=5,5-dioxide Compound, 3,7-diamino-2,8-dimethoxydibenzothiophene=5,5-dioxide, 3,7-diamino-2,6-dimethoxydibenzothiophene= 5,5-dioxide, 3,7-diamino-4,6-dimethoxydibenzothiophene=5,5-dioxide and the like.

In the above general formula (A2b-M), examples of diaminothioxanthene-10,10-diones in which X is -CH ₂ - include: 3,6-diaminothioxanthene-10,10- Diketone, 2,7-diaminothioxanthene-10,10-dione, 3,6-diamino-2,7-dimethylthioxanthene-10,10-dione, 3,6-diamino- 2,8-diethyl-thioxanthene-10,10-dione, 3,6-diamino-2,8-dipropylthioxanthene-10,10-dione, 3,6-diamino-2 , 8-dimethoxythioxanthene-10,10-dione, etc.

In the above general formula (A2b-M), examples of diaminothioxanthene-9,10,10-triketones in which X is -CO- include: 3,6-diamino-thioxanthene-9, 10,10-trione, 2,7-diamino-thioxanthene-9,10,10-trione, etc.

The other diamine component providing the unit A3 is a diamine compound other than the compounds shown above, and a compound that can further improve the performance depending on the situation is selected without impairing the effects of the invention in this section.

Examples include: 3,3'-diaminodiphenylsulfone, 3,4'-diaminodiphenylsulfone, 4,4'-diaminodiphenylsulfone, 4,4'-diamino-3 , 3'-Dimethyldiphenylsulfone and other diaminodiphenylsulfones;

4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl ether, 3,3'-dimethyl-4,4'- Diaminodiphenyl ether, 3,3'-diethoxy-4,4'-diaminodiphenyl ether and other diaminodiphenyl ethers;

4,4'-diaminodiphenylmethane, 3,3'-diaminodiphenylmethane and other diaminodiphenylmethanes;

2,2-bis(3-aminophenyl)propane, 2,2-bis(4-aminophenyl)propane and other 2,2-bis(aminophenyl)propanes;

2,2-bis[4-(4-aminophenoxy)phenyl]propane, 2,2-bis[4-(3-aminophenoxy)phenyl]propane, etc. 2,2-bis(aminophenoxy)propane Oxyphenyl) propanes;

4,4'-diaminobenzophenone, 3,3'-diaminobenzophenone and other diaminobenzophenones;

3,5-diaminobenzoic acid and other diaminobenzoic acids;

1,3-phenylenediamine, 1,4-phenylenediamine and other phenylenediamines;

2,2'-dichloro-4,4'-diaminodiphenyl ether and other dichlorodiaminodiphenyl ethers;

Toluidines such as o-toluidine and m-toluidine;

Dihydroxydiaminobiphenyls such as 2,2'-dihydroxy-4,4'-diaminobiphenyl, etc.

Among them, diaminodiphenylsulfones, diaminodiphenyl ethers, diaminobenzoic acids, dichlorodiaminodiphenyl ethers, and dihydroxydiaminobiphenyls are preferable.

In the case of using an aromatic polyimide represented by a repeating unit of the general formula (1) in an asymmetric air separation membrane, for example, the above-mentioned tetracarboxylic acid component is preferably used in combination with 4,4 '-(hexafluoroisopropylidene-bis(phthalic anhydride), 3,3',4,4'-biphenyltetracarboxylic dianhydride as the carboxylic acid providing unit B2, as the carboxylic acid providing unit B3 In the pyromellitic dianhydride of carboxylic acid, the above-mentioned diamine component is preferably used in combination with 2,2',5,5'-tetrachlorobenzidine as the diamine providing unit A1, and 3 as the diamine providing unit A2, 7-diamino-dimethyldibenzothiophene=5,5-dioxide. 3,7-diamino-dimethyldibenzothiophene=5,5-dioxide refers to 3,7- Diamino-2,8-dimethyldibenzothiophene = isomer 3,7-diamino-2,6-dimethyl containing 5,5-dioxide as the main component and containing a methyl group in a different position Dibenzothiophene = 5,5-dioxide, 3,7-diamino-4,6-dimethyldibenzothiophene = mixture of 5,5-dioxide.

The preparation of the above-mentioned aromatic polyimide solution is preferably carried out by using a two-step method or a one-step method. The above-mentioned two-step method is to add a tetracarboxylic acid component and a diamine component in an organic polar solvent at a prescribed composition ratio, and the Polymerization is carried out at a low temperature to generate polyamic acid, followed by heating for imidization by heating or chemical imidation by adding pyridine, etc.; The carboxylic acid component and the diamine component are polymerized and imidized at a high temperature of 100 to 250°C, preferably about 130 to 200°C. When performing imidation reaction by heating, it is preferable to perform it, removing desorbed water or alcohol. It is preferable to make the density|concentration of the polyimide in a solvent about 5 to 50 weight% with respect to the usage-amount of a tetracarboxylic-acid component and a diamine component with respect to an organic polar solvent, Preferably it is 5 to 40 weight%.

The aromatic polyimide solution obtained by carrying out polymerization imidation can also be used for spinning as it is. In addition, for example, the obtained aromatic polyimide solution may be thrown into a solvent insoluble in the aromatic polyimide, and the aromatic polyimide may be precipitated and separated, and the concentration may be adjusted to a predetermined concentration. Redissolve in organic polar solvents to prepare aromatic polyimide solutions, which are used for spinning.

For the aromatic polyimide solution used for spinning, the concentration of polyimide is preferably 5 to 40% by weight, more preferably 8 to 25% by weight, and the solution viscosity (rotational viscosity) is preferably 100°C It is 100 to 15000 poise, more preferably 200 to 10000 poise, particularly preferably 300 to 5000 poise. When the solution viscosity is lower than 100 poise, it is possible to obtain a homogeneous membrane (membrane), but it is difficult to obtain an asymmetric membrane with high mechanical strength. In addition, when it exceeds 15,000 poises, it is difficult to extrude from the spinning nozzle, so it is difficult to obtain an asymmetric hollow fiber membrane of the desired shape.

The above-mentioned organic polar solvent is not limited as long as it is a solvent that can properly dissolve the obtained aromatic polyimide, but suitable examples include phenols such as phenol, cresol, and xylenol; Catechol directly having two hydroxyl groups, catechols such as resorcinol, 3-chlorophenol, 4-chlorophenol (same as p-chlorophenol described later), 3-bromophenol, 4-bromophenol Phenol solvents composed of phenol, 2-chloro-5-hydroxytoluene and other halogenated phenols, or N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolinone, N,N - Amide-based solvents composed of amides such as dimethylformamide, N,N-diethylformamide, N,N-dimethylacetamide, N,N-diethylacetamide, or their mixed solvents, etc. .

The hollow fiber membrane can be suitably obtained by spinning by a dry-wet method (dry-wet spinning method) using the above-mentioned aromatic polyimide solution or the like. The dry-wet method is to evaporate the solvent on the surface of the polymer solution made into a hollow fiber shape to form a thin dense layer (separation layer), and further immerse it in a coagulation liquid (compatible with the solvent of the polymer solution, and the polymer is insoluble). solvent), utilizes the phase separation phenomenon that occurs at this time to form micropores to form a porous layer (support layer) (phase inversion method), this method is proposed by Loeb et al. (for example, US Pat. No. 3,133,132).

The dry-wet spinning method is a method of forming a hollow fiber membrane by a dry-wet method using a spinning nozzle, and is described in, for example, JP-A-61-133106 or JP-A-3-267130.

The production method generally includes a spinning step (spinning slurry discharge step), a coagulation step, a washing step, a drying step, and a heat treatment step.

First, in the spinning process (spinning slurry ejection process), the spinning nozzle used to discharge the spinning slurry liquid should be a spinning nozzle that extrudes the spinning slurry liquid into a hollow filament. Yes, preferably a tube-in-orifice type nozzle or the like. Usually, the temperature range of the aromatic polyimide solution during extrusion is preferably about 20°C to 150°C, particularly preferably 30°C to 120°C. The preferable temperature range differs depending on the solvent type, viscosity, etc. of the liquid. In addition, spinning is performed while supplying gas or liquid into the interior of the hollow filament extruded from the nozzle.

In the coagulation process continuing from the spinning process, the hollow filaments ejected from the nozzle are once extruded in the air or in an inert gas atmosphere such as nitrogen, and then introduced into a coagulation bath and immersed in a coagulation liquid. The coagulation liquid is preferably a liquid that does not substantially dissolve the aromatic polyimide component and has compatibility with the solvent of the aromatic polyimide solution. Although not particularly limited, water, lower alcohols such as methanol, ethanol, and propanol, ketones having a lower alkyl group such as acetone, diethyl ketone, and methyl ethyl ketone, or a mixture thereof are preferably used. In addition, when the solvent of the aromatic polyimide solution is an amide-based solvent, an aqueous solution of an amide-based solvent is also preferable.

In the following cleaning process, if necessary, wash with a cleaning solvent such as ethanol, and then use a replacement solvent such as isopentane, n-hexane, isooctane, n-heptane and other aliphatic hydrocarbons to replace the outer and inner parts of the hollow fiber. Coagulant and/or cleaning solvent.

In the following drying step, the hollow fiber containing the replacement solvent is dried at an appropriate temperature. Furthermore, in the heat treatment step, it is preferable to perform heat treatment at a temperature lower than the softening point or secondary transition point of the aromatic polyimide used, thereby obtaining an asymmetric gas separation hollow fiber membrane.

(industrial availability)

According to the invention of this part, high temperature air such as 150°C or higher can be supplied to the air separation membrane module to obtain nitrogen-enriched air with increased nitrogen concentration. The method of the invention of this section can be applied, for example, to an explosion protection system of a fuel tank of an aircraft.

(Content of invention)

The invention related to Part A is as follows.

1. A method of using an air separation membrane module to produce nitrogen-enriched air from air, characterized in that,

Air above 150°C is supplied to the air separation membrane module.

2. The method as described in the above 1, characterized in that the oxygen transmission rate (P' _O2 ) at 175°C is 20×10 ^-5 cm ³ (STP)/cm when the air separation membrane module starts to be used ² sec cmHg or more, and the ratio of oxygen transmission rate to nitrogen transmission rate (P' _O2 /P' _N2 ) at 175°C is 1.8 or more, and

_P'O2 and _P'O2 / _P'N2 when used at 175°C for 140 hours maintained 90% or more of the _P'O2 and _P'O2 / _P'N2 before the start of use.

3. The method according to 1 or 2 above, wherein the air separation membrane in the air separation membrane module is formed of a material that does not show a glass transition temperature below 225°C.

4. The method according to the above 1, wherein the air separation membrane exhibits a shape retention rate of 95% or more when left at 175° C. for 2 hours.

5. An explosion-proof method for aircraft, characterized in that nitrogen-enriched air is produced by the production method described in any one of 1 to 4 above, and supplied to fuel tanks for aircraft.

[Part B: Gas separation membrane module having sufficient heat resistance, pressure resistance, etc. under high temperature and high pressure without occurrence of cracks]

(technical field)

The invention in this part relates to a gas separation membrane module for the separation of mixed gases, which integrally fixes a bundle composed of many hollow fiber membranes with selective permeability with a tube sheet cured by a specific epoxy resin composition .

(Background technique)

A hollow fiber type gas separation membrane module is integrally bundled and fixed by a cured plate (tube sheet) of resin for casting at least one end of a bundle of many hollow fiber membranes having selective permeability. In this state, it is an assembly housed in a case having at least a mixed gas inlet, a permeate gas discharge port, and a non-permeate gas discharge port. In addition to the function of integrally fixing the tow, the tube sheet has the function of isolating the inner space and the outer space of the hollow fiber membrane by sealing between the hollow fiber and the hollow fiber and between the hollow fiber and the box, and maintaining the inner space and the outer space. The role of airtightness. When the hollow fiber type gas separation membrane module loses the airtightness due to the above-mentioned tube sheet, proper separation cannot be performed.

In a gas separation method using a separation membrane, appropriate gas separation may be achieved by supplying a gas mixture under high temperature and high pressure. At this time, the tube sheet material is required to have high heat resistance and pressure resistance, and its glass transition temperature or heat distortion temperature must be at least tens of degrees higher than the operating temperature of the gas separation membrane module.

Thermosetting resins are generally used as tube sheet materials for achieving high heat resistance and pressure resistance. However, when forming tube sheets, the curing reaction of the thermosetting resin is completed at a significantly high temperature. deal with. This is because, when a tube sheet that has not completed the curing reaction is used, the curing reaction progresses during the operation of the separation membrane module at a high temperature and the tube sheet shrinks, resulting in insufficient sealing performance between the tube sheet and the tank. Therefore, the tube sheet material is also required to have heat resistance that is significantly higher than the temperature at which the tube sheet is formed.

As a gas separation membrane module that can be used for the separation of mixed gases at high temperature and high pressure, for example, Japanese Patent Application Laid-Open No. 62-74434 describes the use of a novolac epoxy resin and a liquid polybutylene resin having a reactive functional group at the end. A hollow fiber element made of a modified epoxy resin obtained by reacting a diene.

(Problems to be Solved by the Invention of Part B)

However, the existing tube sheet materials have the following problems: large solidification shrinkage during tube sheet molding, cracks or tube sheet damage, etc. In addition, there is a problem that when only the pressure resistance and heat resistance are emphasized, the flexibility of the tube sheet material is insufficient, so that, for example, when an impact is received during operation, cracks are generated on the tube sheet or the tube sheet is broken. The object of the invention in this part is to provide a tube sheet of a gas separation membrane module, which maintains sufficient heat resistance and pressure resistance under high temperature and high pressure without cracks.

The main points of the invention disclosed in this section are as follows.

1. A gas separation membrane module, which has:

A tow consisting of many hollow fiber membranes with gas separation properties,

a casing having a mixed gas inlet, a permeate gas discharge port, and a non-permeate gas discharge port in which the hollow fiber bundle is disposed; and

a tube sheet securing at least one end of said hollow tow,

Wherein, the tube sheet is formed by an epoxy cured product cured from a casting resin composition, and the casting resin composition includes: (a) a novolak type epoxy compound and (b) an epoxy compound at the end that can react with an epoxy group. The modified epoxy resin obtained by reacting the functional group of butadiene-acrylonitrile copolymer, and (c) curing agent.

(Invention Effects of Part B)

The tube sheet in the gas separation membrane module of the invention of this section is manufactured by using a butadiene-acrylonitrile copolymer having a functional group that can react with an epoxy group at the end, and is more flexible than the existing tube sheet . Moreover, when the tube sheet is formed or exposed to high temperature and high pressure gas during the operation of the gas separation membrane module, no cracks will occur on the tube sheet, and the tightness with the hollow wire or the sealing performance between the tube sheet and the box No problem either.

(implementation in Part B)

The epoxy cured product forming the tube sheet of the hollow fiber element of this part of the invention can be obtained by heat-treating and curing a casting resin composition comprising at least: (a) a phenolic ring An oxygen compound, (b) a modified epoxy resin obtained by reacting a butadiene-acrylonitrile copolymer having a functional group capable of reacting with an epoxy group at the terminal, and (c) a curing agent. Below, it demonstrates in detail.

<Modified epoxy resin>

Modified epoxy resin can make novolac type epoxy compound {hereinafter, sometimes also described as epoxy compound (a)} and butadiene-acrylonitrile copolymer {hereinafter, also have When recorded as compound (b)} reaction to get.

The novolac epoxy compound (a) used in the invention of this section is a compound represented by the following general formula (a).

【Chemical 16】

(In the formula, R" represents an alkyl group or a hydrogen atom having 1 to 3 carbon atoms, and n represents an integer of 0 to 500, preferably 0 to 20.)

In the formula (a), R "is preferably a methyl group or a hydrogen atom. For the epoxy compound (a) represented by the above general formula (a), the molecular weight is preferably 300-2000, and the epoxy equivalent is preferably 150-2000. 250. Examples of the epoxy compound (a) include jER152 and jER154 manufactured by Mitsubishi Chemical Co., Ltd.; EPICLON-N740, N-770, and N-775 manufactured by DIC Corporation; YDPN-638, YDCN-700 series, etc.; D.E.N.438 manufactured by Dow Chemical Company, etc.

In the butadiene-acrylonitrile copolymer {compound (b)} having a functional group reactive with an epoxy group at the terminal used in the invention of this section, examples of the functional group reactive with an epoxy group include carboxyl, Amino group, hydroxyl group, etc., carboxyl group is particularly preferable. By containing the compound (b), flexibility can be imparted to the formed tube sheet.

As the butadiene-acrylonitrile copolymer having a functional group capable of reacting with an epoxy group at the end, for example, a carboxyl-terminated butadiene-acrylonitrile copolymer (CTBN) represented by the following general formula (b) is preferable.

【Chemical 17】

In formula (b), m represents the total number of repetitions of butadiene monomer units, n represents the total number of repetitions of acrylonitrile monomer units, and when there are two or more structures in [ ], m and n represent each The sum of the repeating numbers of the units may exist either as a block or randomly.

The molecular weight of CTBN represented by the above general formula (b) is preferably 2,000 to 4,000, and for example, CTBN preferably contains 5 to 50% by weight of acrylonitrile monomer units. As a commercial item, Hypro ^™ CTBN1300×8, CTBN1300×13, CTBN1300×31, etc. manufactured by Emerald Functional Materials are mentioned, for example.

The modified epoxy resin is obtained by mixing compound (b) in an amount of preferably 5 to 50 parts by weight, more preferably 5 to 20 parts by weight with respect to 100 parts by weight of the epoxy compound (a), and reacting it. When using the modified epoxy resin with the content of each compound within the above range, the formed tube sheet does not produce cracks under high temperature and high pressure, and in addition, the glass transition temperature is greatly lowered and the problem of deformation does not occur. In addition, other compounds may also be mixed as long as the object of the invention in this section is not impaired. The reaction conditions for preparing the modified epoxy resin are not particularly limited, but the reaction temperature is preferably 100 to 200° C., and the reaction time is preferably 2 to 5 hours.

<curing agent>

The curing agent used in the invention of this section is not particularly limited as long as it is a thermosetting agent for epoxy resins, and examples thereof include amines, phenols, and acid anhydrides, and acid anhydrides are more preferably used. Examples of acid anhydrides include: phthalic anhydride, pyromellitic dianhydride, methyl-5-norbornene-2,3-dicarboxylic anhydride (methyl nadic anhydride), benzophenone tetracarboxylic Acid dianhydrides and the like, and methyl-5-norbornene-2,3-dicarboxylic anhydride is particularly preferable.

<Curing Accelerator>

The casting resin composition used in the invention of this section may contain a curing accelerator if necessary, and examples of the curing accelerator include imidazole compounds. Examples of imidazole compounds include 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 2-benzene imidazole, 1-benzyl-2-methylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, etc., particularly preferably 2- Ethyl-4-methylimidazole.

<Epoxy cured product>

The epoxy cured product of the tube sheet of the invention of this section can be formed by mixing the above-mentioned modified epoxy resin, curing agent and, if necessary, a curing accelerator. Resin composition) is obtained by heat treatment and curing. The mixing ratio of the modified epoxy resin and curing agent in the preparation of the casting resin composition can be based on the number of epoxy functional groups of the modified epoxy resin and the number of functional groups of the curing agent, and at the same time according to the viscosity of the casting resin composition Wait for appropriate adjustments. In addition, it is preferable that it is 0-5 weight part with respect to 100 weight part of modified epoxy resins, and, as for a hardening accelerator, it is more preferable that it is 0.1-3 weight part.

For the heat treatment, for example, it is preferable to heat and primary cure the casting resin composition to such an extent that the casting resin composition loses its fluidity, and then further post-cure the primary cured resin at high temperature. When performing post-curing, it is preferable to heat-treat the casting resin composition at a temperature higher than the final operating temperature of the module, for example, preferably 100°C to 250°C, more preferably 120°C or higher, so that the physical properties of the tube sheet material do not change during the operation of the module. 2 to 10 hours. In addition, primary curing is not particularly limited. For example, it is preferably performed at less than 100° C., more preferably at 50 to 85° C. for 2 to 24 hours. It should be noted that when the primary-cured resin is heated to the post-curing temperature at a temperature increase rate of 5°C/min or less, there is no problem of thermal runaway due to the heat of reaction rapidly generated inside the casting resin composition, which is preferable. The method of producing the tube sheet will be described later.

<Gas separation membrane module>

Next, the structure of the gas separation membrane module of the present invention will be described.

So-called Bore Feed type and Shell Feed type are known as gas separation membrane modules formed of hollow fiber membranes. For example, in a Bore Feed type gas separation membrane module, as shown in FIG. The hollow fiber bundle is housed in a box B15 having at least a mixed gas inlet B11, a permeable gas discharge port B12, and a non-permeable gas discharge port B13, and the hollow fiber membranes B14 are used as openings at both ends of the hollow fiber bundle. The state is fixed to the box body B15, and the tube plates B16a and B16b are formed, so that the gas is supplied from the mixed gas inlet B11 and passes through the inner side of the hollow fiber membrane B14 to the space of the non-permeable gas outlet B13 (non-permeable side) It is constructed so as to be isolated from the space (permeation side) leading from the outside of the hollow fiber membrane B14 to the permeated gas outlet B12. The box body B15 is made of materials such as metal materials such as stainless steel, plastic materials, fiber-reinforced plastic materials, and ceramics. In the shell feed type gas separation membrane module, for example, as shown in Fig. 3(B), a tube sheet is formed at one end of the hollow fiber bundle, and the gas is supplied from the mixed gas inlet B11 and leads to the non-permeable gas discharge port B13 The space on the non-permeate side is formed outside the hollow fiber membrane B14, and the space on the permeate side leading to the permeate gas outlet B12 is formed inside the hollow fiber membrane B14.

In Fig. 3 (A) and (B), while the mixed gas supplied from the mixed gas inlet B11 of the gas separation membrane module is in contact with the hollow fiber membrane B14 in the gas separation membrane module and flows, the high permeable gas preferentially permeates The hollow fiber membrane B14 is separated into a gas containing a large amount of highly permeable gas (permeable gas) and a non-permeable residual gas containing a small amount of highly permeable gas (non-permeable gas). The permeated gas is discharged from the permeated gas discharge port B12, and the non-permeated gas is discharged from the non-permeated gas discharge port B13. Only one or both of the non-permeate gas and permeate gas discharged from the gas separation membrane module are recovered depending on the application.

As a hollow fiber used for a gas separation membrane, a large number of hollow fibers having a thin thickness and a small diameter can form a high membrane area even in a small device, which can improve separation efficiency and is also economically preferable. Examples of the above-mentioned hollow fibers include those having a film thickness of 10 to 500 μm and an outer diameter of 50 to 2000 μm, and are not particularly limited. In addition, the gas separation membrane may be homogeneous or heterogeneous such as a composite membrane or an asymmetric membrane, and may be microporous or nonporous.

Examples of the gas separation membrane include polymer materials such as polyimide, polyetherimide, polyamide, polyamideimide, polysulfone, polycarbonate, silicone resin, cellulose-based polymer, zeolite, etc. Gas separation membranes formed of ceramic materials, etc. As the gas separation membrane formed of polyimide, for example, an aromatic polyimide hollow fiber separation membrane is preferable, and an aromatic polyimide asymmetric hollow fiber separation membrane is more preferable.

Examples of the arrangement form of the hollow fiber bundles include parallel arrangement, cross arrangement, fabric form, spiral form, and the like. In addition, the hollow fiber bundle may have a core tube at a substantially central portion, and a film may be wound around the outer peripheral portion of the hollow fiber bundle. Furthermore, the shape of the hollow fiber bundle may be cylindrical, flat, or prismatic, and may be stored in the above-mentioned shape directly in the box, bent into a U-shape, or wound into a helical shape.

Next, a method for manufacturing the gas separation membrane module of the invention of this part will be described.

First, a method of bundling hollow fiber membranes as hollow fiber bundles will be described.

As a method of bundling the hollow fiber membranes so that they are alternately arranged at an angle of 5 to 30 degrees with respect to the axial direction, the following methods are mentioned. 1 to 100 hollow fiber membranes are distributed on the core tube by a wire distribution guide device that reciprocates at a constant speed in the axial direction of the tubular object (core tube) that becomes the core, and at the same time, the core tube rotates at a constant speed. Therefore, the hollow fiber membranes are not arranged parallel to the axis, but are arranged at an angle at which only the core tube is rotated with respect to the axial direction. When the wire is distributed to one end, the hollow fiber membrane is fixed here, and the wire distribution guide is turned back in the opposite direction, and further wire distribution is performed. The core tube continues to rotate in the same direction. Therefore, this time, the relative axis direction is the same as that of the last time and the angle of the opposite direction is used for wire distribution. When this is repeated, the aligned hollow fiber membranes are arranged alternately and crosswise on the hollow fiber membranes aligned at opposite angles, and bundled into hollow fiber bundles.

Next, a method of forming the tube sheet in the invention of this part will be described. Examples of methods for forming the tube sheet include a centrifugal forming method and a static forming method, but the static forming method is preferable because the apparatus is simple and productivity can be improved. Hereinafter, an example of the static molding method will be described.

After the hollow fiber bundle with the hollow fiber membranes B24 of predetermined length and number bundled together is stored in the box B22 with the core tube removed or the core tube intact in the approximate center of the bundle by the above-mentioned method, it is placed in the At a predetermined position in the die B21 for forming the tube sheet at the end, the hollow fiber bundle and the cylindrical box B22 are held substantially vertically with the end facing downward. Figure 4b shows a schematic diagram of this state.

A predetermined amount of casting resin composition for forming the tube sheet B23 is injected into the mold B21. Fig. 4c is a schematic diagram showing a state where the casting resin composition has been injected. The injection method of the casting resin composition is not particularly limited, but since it is easy to uniformly inject the casting resin composition into the mold B21 and between the hollow fiber membranes B24, it is preferably injected from the lower part of the mold using a syringe. When the injection rate of the casting resin composition is too fast, it becomes difficult to uniformly inject the casting resin composition into the portion where the casting resin composition should be filled. Therefore, it is preferable to perform the injection for a sufficient time. During injection of the casting resin composition into the mold B21, it is preferable to properly control the temperature of the mold B21. Likewise, it is preferable to control the temperature of the casting resin composition.

The cast resin composition before curing is preferably liquid at the temperature at the time of resin injection from the viewpoint of moldability.

The viscosity of the casting resin composition is not particularly limited, but the viscosity is preferably less than 120 poise, particularly preferably less than 20 poise, at a temperature of 70 to 90°C, which is usually used for resin injection. Here, the viscosity of the resin composition is appropriately measured using a rotational viscometer.

There are following problems: when the viscosity of the casting resin composition is 120 poise or more at 70 to 90° C., it takes a long time to inject the resin at the time of tube sheet molding, and the bubbles generated at the time of resin injection are not easy to disappear, and the resin is insufficient. It penetrates between the hollow fiber membranes and creates voids.

After injecting the casting resin composition into the mold B21, the casting resin composition is primarily cured by keeping the mold B21 and the hollow fiber bundle at a constant temperature to form a tube sheet B23. The temperature at this time is lower than 100°C, preferably 50 to 85°C. When the temperature at this stage is high, the curing reaction of the casting resin composition becomes violent, which affects the strength of the finally obtained tube sheet, which is not preferable.

In order to improve the durability and mechanical properties of the tube sheet, after the casting resin composition is cured, it is preferable to post-cure the casting resin composition by further heating. The temperature at the time of post-curing is preferably 100°C to 250°C. When the temperature at the time of post-curing is lower than 100 degreeC, hardening of a casting resin composition becomes insufficient, and it is unpreferable. In addition, when the temperature at the time of post-curing is too high, the curing reaction of the molded resin composition becomes violent, which causes a problem in the strength of the tube sheet, which is not preferable. When post-curing the casting resin composition, it may be divided into multiple times and heated at respective temperatures.

After the casting resin composition is post-cured, the tube sheet is cut to open the hollow fiber membrane at the end, and the hollow fiber remains open at the end to form a hollow fiber element fixed with the tube sheet.

Here, in the case of forming the tube sheet at both ends of the hollow fiber bundle, it is performed by forming the tube sheet at one end of the hollow fiber bundle by the above-mentioned procedure, and then forming the tube sheet at the other end by the same procedure. After the tube sheet is formed at one end, it may be after the tube sheet is cut and the hollow fiber membrane is opened. In addition, it is also preferable to form a tube sheet at the other end after setting one end in a mold and injecting the casting resin composition for primary curing and before performing post-curing, and post-curing simultaneously at both ends. step.

In the method of separating a mixed gas using the gas separation membrane module of the invention of this section, the mixed gas to be separated is not particularly limited as long as it is a gas mixture of two or more types. The gas separation membrane module of the invention of this section can be suitably used for, for example, separation of nitrogen-rich gas and oxygen-rich gas from air, separation of hydrogen from a mixed gas containing hydrogen, water vapor from a mixed vapor of water vapor and organic vapor Separation (dehydration of organic vapor), etc.

(Technical solutions)

The inventions covered by Section B are as follows.

1. A gas separation membrane module, which has:

A tow consisting of many hollow fiber membranes with gas separation properties,

a casing having a mixed gas inlet, a permeate gas discharge port, and a non-permeate gas discharge port in which the hollow fiber bundle is disposed; and

a tube sheet securing at least one end of said hollow tow,

Wherein, the tube sheet is formed by an epoxy cured product cured from a casting resin composition, and the casting resin composition includes: (a) a novolak type epoxy compound and (b) an epoxy compound at the end that can react with an epoxy group. The modified epoxy resin obtained by reacting the functional group of butadiene-acrylonitrile copolymer, and (c) curing agent.

2. The gas separation membrane module according to the above 1, wherein the casting resin composition further contains a curing accelerator.

3. The gas separation membrane module according to 1 or 2 above, wherein the functional group capable of reacting with an epoxy group is a carboxyl group.

4. The gas separation membrane module according to any one of 1 to 3 above, wherein the curing agent is an acid anhydride.

5. The gas separation membrane module according to any one of 2 to 4 above, wherein the curing accelerator is an imidazole compound.

[Part C: Separation membrane modules that work well even at high temperatures, etc.]

(technical field)

The invention disclosed in this part relates to a separation membrane module, which has a hollow fiber bundle composed of many hollow fiber membranes having selective permeability and a tube sheet cured with a specific epoxy resin composition. Fixed hollow fiber elements. In particular, it relates to a separation membrane module capable of suppressing the influence of thermal expansion of a tube sheet and operating well even at high temperatures.

(Background technique)

A hollow fiber type gas separation membrane module generally includes a hollow fiber element having a bundle of many hollow fiber membranes having permselectivity, and a hollow container for accommodating the element. The hollow fiber bundle of the hollow fiber element is fixed at one or both ends to the end of the container by a cured sheet (tube sheet) of resin. In addition, the container is provided with at least a raw material gas inlet, a permeate gas discharge port, and a non-permeate gas discharge port.

In terms of gas separation membranes, in general, the higher the temperature and pressure of the supplied gas, the greater the gas permeation rate. Therefore, in the case of using a gas separation membrane module, a compressor or the like is used for research to compress the source gas and supply it to the module. This compressed gas may be supplied at a very high temperature of 149°C to 260°C in some cases.

However, when the separation membrane module is used under high temperature conditions as described above, for example, stress concentration may occur in the tube sheet member due to thermal expansion of the tube sheet, or cracks in the tube sheet caused by the concentration may cause loss. The airtightness of the separation membrane module and other issues. Therefore, in general, high-temperature gas compressed by a compressor or the like is deliberately cooled and supplied to the gas separation membrane module. Regarding use at high temperatures, conventional separation membrane modules still have room for improvement (for example, design of high-efficiency components based on special conditions at high temperatures, etc.). Furthermore, regardless of whether it is a separation membrane module for high temperature use, the development of a structure that further simplifies the structure of the separation membrane module and contributes to miniaturization is being sought.

The present invention has been made in view of the above problems, and an object of the invention is to provide a separation membrane module that suppresses the influence of thermal expansion of the tube sheet and can operate well even at high temperatures. Another object is to provide a structure that simplifies the structure of the separation membrane module and contributes to size reduction and weight reduction.

The main points of the invention disclosed in this section are as follows.

1. A separation membrane module, comprising:

Hollow fiber bundles that bundle many hollow fiber membranes with selective permeability;

a cylindrical container containing the hollow tow;

a tube plate provided at the end of the above-mentioned hollow fiber bundle and having a function of fixing the end of the bundle to the end of the above-mentioned cylindrical container while insulating the inside and outside of the above-mentioned cylindrical container; and

an annular sealing member that seals between the outer peripheral surface of the tube sheet and the inner peripheral surface of the cylindrical container;

The separation membrane module is used under high temperature conditions, wherein,

In the periphery where the annular seal member is attached, no step portion is provided on the tube sheet.

According to such a configuration, since no step is provided on the tube sheet around the periphery where the annular seal member (described in detail below) is attached, compared with the conventional structure in which an O-ring is arranged on the step of the tube sheet, the Effects of stress concentration during use at high temperatures.

The "annular sealing member" in this section refers to an annular sealing member that seals between the outer peripheral surface of the tube sheet and the inner peripheral surface of the cylindrical container, and its cross-sectional shape is not particularly limited. The ring-shaped sealing member may be, for example, an O-ring (substantially circular in cross-section), or a V-seal or U-seal having a substantially V-shaped cross-section or a substantially U-shaped cross-section, respectively. Furthermore, cross-sectional shapes such as an ellipse, a rectangle, a polygon, and an X shape are also included.

"Under high temperature conditions" means within the range of 80°C to 300°C.

The "cylindrical container" is not limited to a container that is open at both ends, but also includes a container that is open at only one end.

Gas separation membrane modules can be used for applications such as oxygen separation, nitrogen separation, hydrogen separation, water vapor separation, carbon dioxide separation, and organic vapor separation.

(1st embodiment in part C)

Fig. 5 is a schematic diagram showing the basic configuration of a gas separation membrane module. In addition, in the following description, although some embodiment is illustrated, each embodiment is not independent, and the content of each embodiment can be combined suitably.

As shown in FIG. 5 , the gas separation membrane module 1 includes a hollow fiber bundle 15 which is a bundle of many hollow fiber membranes 14 having selective permeability, and a substantially cylindrical container 10 for accommodating the hollow fiber bundle 15 . As an example, the cylindrical container 10 is made of metal, and its both ends are opened. The cylindrical container 10 may have a circular cross section, an oval cross section, or a polygonal cross section. In the following description, the case where the cross section is circular (that is, the container 10 is cylindrical) will be described as an example.

The hollow fiber membrane 14 can be a conventionally known hollow fiber membrane, and it can be a hollow fiber membrane of any material as long as it has gas separation performance. Hollow fiber membranes made of, for example, polymer materials, especially polyimide, polysulfone, polyetherimide, polyphenylene ether, polycarbonate, and other polymer materials that are glassy at room temperature (23°C) The gas separation performance is good, so it is preferable.

The hollow fiber bundle 15 is a bundle obtained by bundling, for example, about 100 to 1,000,000 hollow fiber membranes. The shape of the bundled hollow fibers is not particularly limited, but from the viewpoint of easiness of manufacture and pressure resistance of the container, it is preferable to bundle the hollow fibers into a cylindrical shape. In addition, although the form in which the hollow fiber membranes were substantially parallel arranged was shown in FIG. 5, the form in which each hollow fiber membrane is arranged crosswise may be sufficient.

Referring again to FIG. 5 , at each end of the container 10 , a tube sheet 30 is provided at the end of the hollow fiber bundle 15 , and an annular sealing member 17 is disposed on the outer periphery thereof. The annular seal member 17 may be, for example, an O-ring (a substantially circular cross-sectional shape), or a V-seal or a U-seal having a substantially V-shaped cross-sectional shape or a substantially U-shaped cross-sectional shape, respectively. In the following description, the case of an O ring will be described as an example.

As an example, the tube sheet 30 is formed of a cured product of an epoxy resin composition (details will be described later), and is formed in a substantially disc shape such that it is fitted into the end of the container 10 . A plurality of hollow fiber membranes 14 penetrate the tube sheet 30 in its thickness direction, and the ends of each hollow fiber membrane 14 are opened on the outer surface of the tube sheet 30 . The tube sheet has the function of integrally fixing many hollow fiber membranes. In addition, the tube sheet cooperates with the ring-shaped sealing member to seal the hollow fiber membranes and between the hollow fiber membranes and the inner peripheral surface of the container, and has the function of isolating the inner space and the outer space of the hollow fiber membranes and maintaining airtightness. .

The cured resin forming the tube sheet 30 is not particularly limited as long as it has high temperature resistance and can maintain airtightness in the hollow fiber module. When used for dehydration or humidification of organic vapor, it is preferable to have durability against water vapor at the same time. Generally, it is preferable to use a thermosetting resin such as polyurethane or epoxy resin. From the standpoint of high temperature resistance and strength, epoxy resin is particularly preferably used. For epoxy resins, for example, in the case of nitrogen membrane modules, epoxy resins described in Japanese Patent Publication No. 2-36287 and the like can be used, and in the case of organic vapor separation modules, WO2009/044711 and the like can be used. The epoxy resin described in.

As shown in FIG. 5 , in the separation membrane module 1 , caps 20 and 21 are respectively provided at both ends of the cylindrical container 10 . A mixed gas inlet port 22A is formed in the cap 20 , and a non-permeable gas discharge port 22B is formed in the cap 21 . A discharge port 12 for permeated gas is formed in a part of the peripheral wall of the container 10 . It should be noted that, as will be described later, the main feature of the invention of this section is the peripheral structure of the tube sheet 30 , and as long as such a structure can be adopted, the type of the separation membrane module is not limited in any way.

Next, the peripheral structure of the tube sheet will be described with reference to FIG. 6 . FIG. 6( a ) shows an example of the structure of the end portion of the module according to the present invention, and FIG. 6( b ) shows another structure.

In the case of the gas separation membrane module shown in FIG. 6( b ), an O-ring 18 is provided between the inner peripheral surface of the cylindrical container 10 and the outer peripheral surface of the tube sheet 530, thereby ensuring airtightness between the two members. . Specifically, a stepped portion 530s is formed on a part of the outer peripheral portion of the tube sheet 530, and the O-ring 18 is fitted into the stepped portion 530s. In the case of such a structure, when the gas separation membrane module 101 is used at a high temperature, stress concentration may occur near the stepped portion 530s of the tube sheet 530 depending on the conditions, and the tube sheet may be damaged or the airtightness may be impaired due to the damage. bad situation.

In order to cope with this, as shown in FIG. 6( a ), in the structure of the present embodiment, a tube plate 30 having no stepped portion on the outer peripheral surface is used. In this example, the diameter of the tube sheet 30 is constant in its total length (other forms will be described later with reference to FIG. 7 ). A stepped portion 10s is provided at an end portion of the cylindrical container 10, whereby a groove for fitting the O-ring 18 is formed in the stepped portion. As an example, the cross-sectional shape of the groove is a rectangle. The O-ring 18 fits into this groove, and ensures airtightness between the outer peripheral surface of the tube sheet and the inner peripheral surface of the cylindrical container.

In addition, the O-ring 18 is also in close contact with the inner surface of the cap 20, thereby ensuring airtightness between the container end and the inner surface of the cap. According to such a configuration, one O-ring 18 is used for sealing both (i) between the tube sheet and the cylindrical container and (ii) between the cap and the cylindrical container, and thus additional O-rings are not required.

It should be noted that the means for fixing the cap 20 to the cylindrical container 10 is not particularly limited, and various conventionally known methods (for example, fixing by adhesion, fixing using a fixing device, etc.) can be used.

In the gas separation membrane module 1 of the present embodiment configured as described above, no step is provided on the tube sheet 30 around the periphery where the O-ring 18 is attached. Therefore, compared with the conventional structure as shown in FIG. 6( b ), it is less susceptible to the influence of stress concentration during use at high temperature. As a result, the high temperature resistance and reliability of the gas separation membrane module 1 as a whole can be improved.

Such an advantage is not limited to FIG. 6( a ), and can be similarly obtained even in the case of the structure shown in FIG. 7 . That is, in the form of FIG. 6( a ), in order to simplify the description, the means for restricting the axial movement of the tube plate 30 is not particularly described, but this means is provided in the configuration of FIG. 7 .

As shown in Fig. 7, in this gas separation membrane module 1', a step 10t is formed at a predetermined distance from the end of the container 10 to the inside. In order to correspond thereto, a step 30't is also provided at the end of the tube sheet 30'. About other structures, it is the same as that of FIG. 6(a). According to such a configuration, the end portion (right side in the drawing) of the tube sheet 30' abuts on the step 10t to restrict the movement in the axial direction, so that the tube sheet does not enter the inside above it.

It should be noted that the gas separation membrane module in FIG. 5 was taken as an example for description above, and of course, the invention of this part can also be applied to other configurations. For example, it can also be preferably applied to a module of a shell feed type or a module of a type for purging in which a purge gas inlet is further provided in a cylindrical container.

(2nd embodiment in part C)

FIG. 8 shows an example of the structure of the end portion of the module according to the second embodiment. FIG. 8( a ) shows the state at room temperature, and FIG. 8( b ) shows the state at high temperature during use.

The gas separation membrane module in FIG. 8 is the same as the above-mentioned embodiment, and includes a hollow fiber bundle 15 in which many hollow fiber membranes having selective permeability are bundled, and a cylindrical container 10 for accommodating the hollow fiber bundle. In addition, a tube plate 38 provided at the end of the hollow fiber bundle 15 and a cap 20 attached to the end of the cylindrical container 10 are provided. The same reference numerals as those in the above-mentioned drawings are assigned to the same structural parts as those in the above-mentioned embodiment, and repeated explanations will be omitted.

As shown in FIG. 8( a ), in this gas separation membrane module, the diameter of the tube sheet 38 at room temperature is formed so that it is slightly smaller than the inner diameter of the inner peripheral surface 10 a of the cylindrical container 10 , and on the outer peripheral surface of the tube sheet 38 A gap is formed with the inner peripheral surface 10a of the cylindrical container. The tube sheet 38 is made of a resin material such as epoxy resin, which has a higher coefficient of thermal expansion than the material of the cylindrical container 10 (metal as an example) as in the above-mentioned embodiment.

The gas separation membrane module is used, for example, in the range of 80°C to 300°C. As shown in FIG. 8( b ), the tube plate 38 is heated to a predetermined temperature during use and expanded in diameter by thermal expansion, whereby the outer peripheral surface thereof is in close contact with the inner peripheral surface 10 a of the cylindrical container. With this close contact, airtightness between the two members can be ensured.

When this gas separation membrane module is used, the temperature of the module is sufficiently raised to secure the airtightness of the tube sheet 38 and the cylindrical vessel 10, and then the mixed gas is supplied.

In the above configuration, the thermal expansion of the tube sheet 38 exerts a sealing effect between the tube sheet and the cylindrical container. Therefore, in order to seal between the two members, it is not necessary to separately provide an O-ring or to bond the outer peripheral surface of the tube sheet to the inner peripheral surface of the cylindrical container. In addition, since the stress applied to the cylindrical container 10 is also reduced when the tube sheet 38 is thermally expanded, it is also advantageous in that damage to the cylindrical container 10 can be prevented.

It should be noted that, in the above description, the case where the tube sheet is made of epoxy resin and the cylindrical container is made of metal has been described. It is not limited to metal. In addition, although not shown in FIG. 8 , a sealing device for sealing between the cap 20 and the cylindrical container 10 may be provided. For example, an annular sealing member arranged between the inner peripheral surface of the cap 20 and the outer peripheral surface of the cylindrical container 10 or an annular sealing member arranged between the inner surface of the cap 20 and the end surface of the cylindrical container 10 may be used.

(3rd embodiment in part C)

FIG. 9 shows an example of the structure of the end portion of the module according to the third embodiment. It should be noted that the modules of the first and second embodiments are intended to be used at high temperatures, and the usage temperature of the gas separation membrane module shown in FIG. 9 is not particularly limited.

The gas separation membrane module of FIG. 9 is the same as the above-mentioned two embodiments, and includes: a hollow fiber bundle 15 bundled with many hollow fiber membranes having selective permeability; a cylindrical container 10 for accommodating the hollow fiber bundle; A tube sheet 30 is provided at an end of the tow 15 and a cap 20 is attached to an end of the cylindrical container 10 . In addition, an O-ring 18 for sealing between the tube sheet and the cylindrical container is also provided. The same reference numerals as those in the above-mentioned drawings are assigned to the same structural parts as those in the above-mentioned embodiment, and repeated explanations will be omitted.

In the configuration of FIG. 9 , an opening 10h for discharging permeated gas that has permeated the hollow fiber membrane to the outside of the cylindrical container 10 is formed in a part of the peripheral wall of the cylindrical container 10 . Moreover, the opening part 20h is also formed in the position corresponding to a part of the peripheral wall of the cap 20. As shown in FIG. A hollow discharge pipe 41 is attached so as to pass through the openings 10h and 20h. In the gas separation membrane module of FIG. 9 , the discharge pipe 41 functions as the permeate gas discharge port 12 of FIG. 5 , and therefore, the permeate gas discharge port 12 of FIG. 5 is not provided.

The discharge pipe 41 also functions as a device for fixing the cap 20 and the cylindrical container 10 . That is, the movement in the axial direction and the movement in the rotational direction between the cap 20 and the cylindrical container 10 are restricted by passing the discharge pipe 41 through the openings 10h and 20h.

In order to fix both members 10 and 20 more firmly, additional fixing screws 42 shown in FIG. 9 can be used. The fixing screw 42 communicates with a threaded hole formed in the peripheral wall of the cap 20 , and its tip enters a part of the peripheral wall of the cylindrical container 10 . The female thread for fixing the fixing screw 42 may be formed on the cap 20 or may be formed on the cylindrical container. It should be noted that, instead of fixing screws, fixing pins may also be used.

It should be noted that an annular sealing member (not shown) may be provided for sealing between the inner peripheral surface of the peripheral wall of the cap 20 and the outer peripheral surface of the cylindrical container 10 . Thereby, the airtightness between the cap 20 and the cylindrical container 10 can be ensured more fully. When a single O-ring 18 is used to sufficiently seal both the tube sheet-cylindrical container and the cap-cylindrical container, this sealing member can be omitted.

In the configuration described above, the member 41 for forming the flow path for discharging the permeated gas also functions as the fixing cap 20 and the cylindrical container 10 . Therefore, the structure of the module is simplified, and the weight and size of the module can be reduced.

In addition, in the example of FIG. 9, the discharge pipe 41 which discharges the permeated gas which permeate|transmitted the hollow fiber membrane to the outside of a cylindrical container was demonstrated as an example. However, instead of the discharge pipe 41 , another tubular member forming a flow path communicating the inside and outside of the cylindrical container may be used.

Alternatively, a configuration may be employed in which the passage of the discharge pipe 41 through the openings 10h and 20h of the container and the cap is omitted, and the cap 20 is fixed to the cylindrical container 10 only by fixing members such as fixing screws 42 or fixing pins. In the case of such a structure, compared with the structure which fixes the flange parts mentioned later with reference to FIG.

There may be only one fixing member, or there may be two or more fixing members, but when there are two or more fixing members, it is preferable that the fixing members are evenly arranged in the circumferential direction.

(Other implementations in Part C)

In addition to the above-mentioned embodiment, the invention of this part may also be the form shown to Fig.10 (a), (b). These gas separation membrane modules are the same as the above-mentioned embodiment, and include: a hollow fiber bundle 15 bundled with hollow fiber membranes; a cylindrical container 10 for accommodating the hollow fiber bundle; a tube plate 30 provided at the end of the hollow fiber bundle 15; Caps 26, 27 attached to the ends of the cylindrical container. In addition, an O-ring 18 for sealing between the outer peripheral surface of the tube sheet and the inner peripheral surface of the cylindrical container is also provided.

In the configuration of FIG. 10( a ), the cap 26 is screwed and fixed to the cylindrical container 10 . That is, the internal thread portion formed on a part of the inner peripheral surface of the cap 26 is configured to engage with the male thread portion formed on a part of the outer peripheral surface of the cylindrical container 10 . In the state where the cap 26 is rotated to a predetermined fixed position (see FIG. 10(a)), a part of the O-ring 18 is in contact with the inner surface of the cap 26, whereby the airtightness between the end of the cylindrical container and the inner surface of the cap can be ensured. sex. Like the above-mentioned embodiment, the O-ring 18 also ensures the airtightness between the outer peripheral surface of the tube sheet and the inner peripheral surface of the cylindrical container.

In the structure of FIG.10(b), the flange part 27f is formed in the cap 27, and the flange part 10f corresponding to it is also formed in the cylindrical container 10 at the same time. Fixing of the cap 27 and the cylindrical container 10 is performed by fixing these flanges 27 f and 10 f with a fixing device 43 . As the fixing means 43, for example, bolts and nuts can be used. In addition, screw holes and bolts formed in the flange 10f may also be used. The places where the flange parts are fastened by the fixing device 43 are not particularly limited, but the fastening places are preferably provided at equal intervals in the circumferential direction of the flange parts.

(yet another embodiment in part C)

The gas separation membrane module of the invention of this part may also have the configuration shown in FIG. 11 . FIG. 11( a ) is a cross-sectional view showing an example of a gas separation membrane module, and FIG. 11( b ) is an enlarged view of a part of FIG. 11( a ).

The gas separation membrane module of FIG. 11 includes: a hollow fiber bundle 115 bundled with hollow fiber membranes; a cylindrical container 110 for accommodating the hollow fiber bundle; tube sheets 130A, 130A provided at both ends of the hollow fiber bundle 115; Caps 120 , 121 are mounted on the ends of the container 110 . In addition, an O-ring 118 provided on the outer peripheral surface of each tube plate 130A is also provided.

In this example, a cylindrical container 110 has a pipe 111 extending in the longitudinal direction of the unit, and end members 112, 112 attached to both ends thereof. On the peripheral wall of the end member 112 on the left side (gas introduction side) in the drawing, a discharge port 112h through which gas (one example) passes is formed.

A flange portion 112 f is formed on each end member 112 . On the other hand, flange portions 120f and 121f are also formed on the respective caps 120 and 121 . By butting the flange portion 112f of the end member and the flange portion 120f of the cap, the cap 120 can be fixed to the end portion using, for example, bolts and nuts (not shown in FIG. 11 ) in the same manner as in FIG. 10 . Member 112 (the same applies to the cap 121).

As shown in FIG. 11( b ), in this example, the tube sheet 130A is arranged so as to be in close contact with a part of the inner peripheral surface of the cap 120 and a part of the inner peripheral surface of the cylindrical container 110 . Each tube plate 130A is similar to the tube plate 30 ′ in FIG. 7 , and its outer peripheral surface is formed in a stepped shape. The stepped portion of the tube plate outer peripheral surface contacts the stepped portion of the inner peripheral surface of the cylindrical container, thereby restricting the axis of the tube plate 130A. Direction (horizontal direction in the figure) position.

On the radially inner side of the flange portion 120f of the cap 120, a stepped portion 120s is formed in an annular shape. An O-ring 118 is disposed in an annular groove (rectangular cross-sectional shape) formed by the stepped portion 120 s and a part of the flange portion 112 f of the end member 112 . The O-ring 118 ensures airtightness between the tube sheet 130A and the cap 120 while ensuring airtightness between the cap 120 and the end member 112 .

Taking the structure of the cap 120 as an example, the peripheral structure of the O-ring 118 has been described, and the structure on the side of the cap 121 is also the same. The means for fixing the flange portion is not limited to a device using bolts and nuts. For example, the tip of a bolt may be screwed into a threaded hole formed in either of the flange portions 112f and 120f.

In the configuration shown in FIG. 11 described above, similarly to the first embodiment, no step portion is provided on the tube plate 130A around the periphery where the O-ring 118 is attached. Therefore, compared with the conventional structure shown in FIG. 6( b ), it is less susceptible to the influence of stress concentration during use at high temperature. As a result, the high temperature resistance and reliability of the gas separation membrane module as a whole can be improved.

In addition, in the structure of FIG. 11, the cylindrical container 110 is comprised by the pipe material 111 and the end members 112, 112, According to this structure, it is advantageous in that the material of each member can be suitably selected according to the property of each member. In addition, the invention of this section is not limited thereto, and a single cylindrical container in which the pipe material 111 and the end member 112 are integrated may be used.

The gas separation membrane module of this part of the invention may also be the module shown in FIG. 12 . This assembly is basically the same as the configuration of FIG. 10(b), and the cap 127 is fixed to the cylindrical container 110' so that the flange portion 127f of the cap 127 and the flange portion 110f of the cylindrical container 110' butt against each other. The number of O-rings and arrangement positions are different from those in Fig. 10(b). The tube sheet 130B is in close contact with a part of the inner peripheral surface of the cap 127 and a part of the inner peripheral surface of the cylindrical container 110', similarly to the unit shown in Fig. 11 .

The first O-ring 118 is disposed in an annular groove 127 g formed on the inner peripheral surface of the cap 127 , and ensures airtightness between the tube plate 130B and the cap 127 . The annular groove 127g is not limited, but is formed on the inner peripheral surface of the cap 127 at a position slightly inward (left side in the figure) from the end surface on the flange portion 127f side.

The second O-ring 119 is disposed between the flange portion 110f and the flange portion 127f. In this example, an O-ring 119 is disposed in an annular groove 110g formed in a flange portion 110f of the cylindrical container 110 . Such an O-ring 119 is not an essential configuration, and the O-ring 119 can prevent gas from leaking to the outside through the gap between the flange portions 110f and 127f.

It should be noted that, of course, the configuration of such O-rings 118 and 119 is not limited to the form described in FIG. 12 , and can be used in combination with the above-mentioned embodiment as appropriate. In addition, a groove for arranging the second O-ring 119 may be formed in the flange portion 127 f of the cap 127 .

(Content of invention)

The invention relating to Part C is as follows.

1. A gas separation membrane module, comprising:

Hollow fiber bundles that bundle many hollow fiber membranes with selective permeability;

a cylindrical container containing the hollow tow;

a tube plate provided at the end of the above-mentioned hollow fiber bundle and having the function of fixing the end of the bundle to the end of the above-mentioned cylindrical container while insulating the inside and outside of the above-mentioned cylindrical container; and

an annular sealing member that seals between the outer peripheral surface of the tube sheet and the inner peripheral surface of the cylindrical container;

The gas separation membrane module is used under high temperature conditions, wherein,

In the periphery where the annular seal member is attached, no step portion is provided on the tube sheet.

2. A gas separation membrane module, comprising:

Hollow fiber bundles that bundle many hollow fiber membranes with selective permeability;

a cylindrical container containing the hollow tow; and

a tube sheet provided at the end of the above-mentioned hollow fiber bundle and having the function of fixing the end of the bundle to the end of the above-mentioned cylindrical container and simultaneously isolating the inside and outside of the above-mentioned cylindrical container;

The gas separation membrane module is used under high temperature conditions, wherein,

The tube sheet is formed of a material having a higher coefficient of thermal expansion than the material of the cylindrical container, and

At normal temperature, a gap is formed between the outer peripheral surface of the tube sheet and the inner peripheral surface of the cylindrical container, and when the temperature rises to a predetermined temperature, the tube sheet expands and its outer peripheral surface is in close contact with the inner peripheral surface of the cylindrical container. And play a sealing effect.

3. A gas separation membrane module, comprising:

Hollow fiber bundles that bundle many hollow fiber membranes with selective permeability;

a cylindrical container containing the hollow tow;

a tube plate provided at the end of the above-mentioned hollow fiber bundle and having the function of fixing the end of the bundle to the end of the above-mentioned cylindrical container while insulating the inside and outside of the above-mentioned cylindrical container; and

A cap mounted on the end of the above-mentioned cylindrical container; wherein,

A tubular member forming a flow path communicating the inside and outside of the cylindrical container is provided (in the radial direction) through a part of the cylindrical container and a part of the cap.

4. The gas separation membrane module as described in the above 3, which also has:

A fixing member communicates with a part of the peripheral wall of the cap and functions to fix the cap and the cylindrical container.

5. A gas separation membrane module, comprising:

Hollow fiber bundles that bundle many hollow fiber membranes with selective permeability;

a cylindrical container containing the hollow tow;

a tube plate provided at the end of the above-mentioned hollow fiber bundle and having the function of fixing the end of the bundle to the end of the above-mentioned cylindrical container while insulating the inside and outside of the above-mentioned cylindrical container; and

A cap mounted on the end of the above-mentioned cylindrical container; wherein,

A fixing member communicating with a part of the peripheral wall of the cap and functioning to fix the cap and the cylindrical container is provided.

6. A gas separation membrane module, comprising:

Hollow fiber bundles that bundle many hollow fiber membranes with selective permeability;

a cylindrical container containing the hollow tow;

a tube sheet provided at the end of the above-mentioned hollow fiber bundle and having the function of fixing the end of the bundle to the end of the above-mentioned cylindrical container and simultaneously isolating the inside and outside of the above-mentioned cylindrical container;

a cap mounted on the end of the above-mentioned cylindrical container; and

an annular sealing member that seals between the outer peripheral surface of the tube sheet and the inner peripheral surface of the cylindrical container;

Wherein, the mode of fixing the above-mentioned cap to the above-mentioned cylindrical container is as follows:

or

(ii) A form in which the flange portion of the cap and the flange portion of the cylindrical container opposed thereto are connected and fixed by a fixing device.

7. The gas separation membrane module according to any one of 3 to 6 above, wherein the annular sealing member also seals between the cap and the cylindrical container.

[Part D: The gas separation membrane module that can control the cost of replacement and is also advantageous for the simplification of the structure]

(technical field)

The invention disclosed in this section relates to a gas separation membrane module for gas separation using a plurality of hollow fiber membranes having selective permeability. In particular, it relates to a separation membrane module which can control the cost of replacement and is also advantageous for simplification of the structure.

(Background technique)

A hollow fiber type gas separation membrane module generally includes a hollow fiber element having a bundle of many hollow fiber membranes having selective permeability, and a cylindrical container for accommodating the element. The hollow fiber bundle of the hollow fiber element is fixed at one or both ends to the end of the container by a cured sheet (tube sheet) of resin. A cap member is attached to an end portion of the cylindrical container, thereby sealing the inside of the container.

In the conventional gas separation membrane module, cap members are attached to the ends of the cylindrical container as described above, and these cap members form a single main body as a whole. Therefore, when replacing the separation membrane module, the whole module needs to be replaced. Therefore, there is a problem in that cap members and the like that do not need to be replaced originally are also replaced together, and the cost of replacement parts increases.

On the other hand, it is also conceivable that only the hollow fiber element in the main body can be replaced, but in this case, for example, a structure for attaching and detaching the hollow fiber element needs to be built in the main body, which leads to a complicated module structure and is also disadvantageous for weight reduction.

The present invention has been made in view of the above-mentioned problems, and an object thereof is to provide a gas separation membrane module that can control the cost at the time of replacement, is also advantageous for simplification of the structure, and can be easily reduced in size and weight.

The main points of the invention mainly disclosed in this part are as follows.

1. A gas separation membrane module, comprising:

A cartridge in which a hollow fiber bundle composed of many hollow fiber membranes is accommodated in a cylindrical container;

cap members mounted on both ends of the box;

a sealing member sealing between each of the above-mentioned cap members and the above-mentioned case; and

fixing means for fixing said cap members to each other;

However, the cartridge is configured to be replaceably attached between the cap members.

According to such a configuration, it is possible to provide a gas separation membrane module in which the replacement cost can be suppressed, the structure can be simplified, and the size and weight can be easily reduced.

(implementation in part D)

Hereinafter, one embodiment of the invention of this part will be described with reference to the drawings. It should be noted that the inventions of this section are not limited to the configurations shown in the following embodiments, and addition or omission of components, changes in shape, and the like may be performed as necessary.

As shown in FIG. 13 , this gas separation membrane module 201 (hereinafter also simply referred to as a separation membrane module) includes: a cylindrical case 210 in which hollow fiber bundles 215 are housed; cap members 220 attached to both ends thereof; 221; and a fixing rod 245 for fixing these cap members 220, 221; and the like.

The cassette 210 has a cylindrical container 211 with both ends open, a hollow fiber bundle 215 and tube sheets 230 and 231 accommodated therein. The tube sheets 230 , 231 hold the ends of the hollow fiber bundle 215 while insulating the inside and outside of the cylindrical container 211 .

As the hollow fiber bundle 215, conventionally known hollow fiber bundles can be used. The hollow fiber bundle 215 may be, for example, a hollow fiber bundle formed by bundling approximately 100 to 1,000,000 hollow fiber membranes 214 . The hollow fiber membrane 214 may be a hollow fiber bundle of any material as long as it has gas separation performance. For example, hollow fiber membranes made of polymer materials, especially polyimide, polysulfone, polyetherimide, polyphenylene ether, polycarbonate and other polymer materials that are glassy at room temperature (23°C) , its gas separation performance is good, so it is preferred. The shape of the bundled hollow fibers is not particularly limited, and may be a bundle of hollow fibers bundled into a cylindrical shape from the viewpoint of easiness of manufacture and pressure resistance of the container. In addition, although the form in which the hollow fiber membranes 214 were arrange|positioned substantially parallel was shown in FIG.

The cross-sectional shape of the cylindrical container 211 may be any shape such as a circle, an ellipse, or a polygon. In the following description, an example of a circle will be described. As an example, the cylindrical container 211 can be manufactured by processing one metal tube. In this embodiment, as an example, it is preferable not to provide a device for fixing the cap members 220, 221 to the cylindrical container 211 on the cylindrical container 211 as the box side (that is, there is no fixed cap on the cylindrical container). component structure). This eliminates the need for processing of the cylindrical container 211, such as fabrication of flanges, formation of screw holes, arrangement of fixing pins, and the like.

As shown in FIG. 14 , an inner peripheral groove 217 is formed in the vicinity of the end in the interior of the cylindrical container 211 , and the inner diameter part becomes larger. Parts of the tube sheets 230 and 231 are fitted into the inner peripheral groove 217 as will be described later. Another inner peripheral groove 218 is formed further inside (in the direction away from the end) at a predetermined interval from the inner peripheral groove 217 . Regarding each of the inner peripheral grooves 217 and 218 , the cross-sectional shape of the dug grooves may be, for example, rectangular, substantially rectangular, trapezoidal or substantially trapezoidal.

In the portion where the inner peripheral groove 218 is formed, a plurality of openings 212 for discharging the gas in the container to the outside are formed. The number and positions of the openings 212 are not particularly limited. As an example, a plurality of openings 212 may be formed at equal intervals around the cylindrical container 211 . As shown in FIG. 14 , an outer peripheral groove 219 for fitting an elastic ring member R2 to be described later is formed on the outer periphery of the cylindrical member 211 slightly inside the inner peripheral groove 218 (in the direction away from the cylindrical end).

The tube plates 230 and 231 (see FIG. 13 ) of the cartridge 210 are made of epoxy resin as an example, and are formed in a substantially disk shape so as to fit into the end of the container 211 . Since the tube sheet 230 and the tube sheet 231 basically have the same structure, only one tube sheet 230 will be described below. Each hollow fiber membrane 214 runs through the tube sheet 230 along its thickness direction, and the end of each hollow fiber membrane 214 is opened on the outside of the tube sheet 230 . The tube sheet 230 integrally fixes a plurality of hollow fiber membranes 214 and also isolates the inside and outside of the cylindrical container 211 . The cured resin forming the tube sheet is not particularly limited as long as it has sufficient durability and can maintain the airtightness in the hollow fiber module. When used for dehydration or humidification, it is preferable to have durability against water vapor at the same time. Generally, it is preferable to use a thermosetting resin such as polyurethane or epoxy resin. In view of durability and strength, epoxy resin is particularly preferably used. For example, in the case of a nitrogen membrane module, epoxy resins described in Japanese Patent Publication No. 2-36287 and the like can be used. In addition, in the case of organic vapor separation modules, the epoxy resins described in WO2009/044711 can be used. Epoxy like that. The tube sheet is preferably formed by known methods such as centrifugal molding and stationary molding.

It should be noted that, in the above, the tube sheet "isolates" the inside and outside of the cylindrical container means that the tube sheet can be used to substantially isolate, and the outer peripheral portion of the tube sheet does not necessarily need to be bonded to the inner surface of the cylindrical container.

As shown in FIG. 13 , a part of the tube sheet 230 protrudes slightly from the end of the cylindrical container 211 , and a chamfered surface (tapered surface) is formed along the outer periphery of the end of the tube sheet 230 . As a step of producing the tube sheet 230 , as an example, first, the hollow fiber bundle 215 is arranged in the cylindrical container 211 , and a mold (an example) not shown is attached to the end of the cylindrical container 211 in this state. Next, resin is injected into the mold and the cylindrical container 211 to be cured. After the resin is cured, the mold is removed, and the end of the cured resin is cut to form the end face of the tube sheet 230 and open the end of the hollow fiber membrane 214 . The chamfered surface of the tube sheet 230 may be formed by using a mold, or may be formed by secondary processing after the resin is cured.

Since the inner peripheral groove 217 is formed in the cylindrical container 211 , the resin of the tube plate 230 is also filled in the groove 217 . As a result, a part of the tube plate 230 is engaged with the inner peripheral groove 217, and the axial direction positioning of the tube plate 230 with respect to the cylindrical container 211 is performed. Normally, when the separation membrane module 201 is used, pressure in the direction in which the tube sheet 230 is pushed into the cylindrical container 211 acts. According to the configuration of the present embodiment, since a part of the tube plate 230 is engaged with the inner peripheral groove 217, the tube plate 230 is not pushed into the cylindrical container 211 by the pressure during use.

Next, the structures of the cap members 220 and 221 will be described with reference to FIGS. 13 and 15 . In this example, since the cap members 220 and 221 basically have the same structure, only one cap member 220 will be described below, and only the different parts of the cap member 221 will be described. The material of the cap members 220 and 221 is not particularly limited, and may be made of metal, for example. It should be noted that, of course, each cap member 220, 221 may have a different shape, and the shape of each cap member 220, 221 may be appropriately changed according to the application or specification of the separation membrane module.

As shown in FIGS. 13 and 15 , the cap member 220 has a bottomed cylindrical shape. Specifically, as shown in FIG. 15(A), it has an end surface 220A covering the opening of the cylindrical container 211 and a cylindrical portion 220B extending from the peripheral edge thereof.

A gas introduction port P1 for introducing a mixed gas is formed on the end surface 220A. Inner peripheral grooves 227 a and 227 b are formed inside the cylindrical portion 220B. As shown in FIG. 13, an elastic ring member R1 for sealing is fitted into the inner peripheral groove 227a (details will be described later). The other inner peripheral groove 227 b is used to form a gas flow path P3 that reciprocates once in the cylindrical container 211 when the cap member 220 is fitted into the cylindrical container 211 . In addition, the non-permeable gas discharge port P2 is formed in the other cap member 221 .

The gas flow path P3 ( FIG. 13 ) communicates with a plurality of openings 212 of the cylindrical container 211 , and the gas inside the container flows into the gas flow path P3 through the openings 212 . This gas is discharged to the outside from one discharge port 223 formed in the cylindrical portion 220B of the cap. In addition, in the form of FIG. 13, the structure (opening part) corresponding to the discharge port 223 is not formed in the cap member 221. As shown in FIG. However, one or more openings 212 may be provided in the cylindrical container 211 corresponding to the opening provided in the cap member 221 depending on the use of the module or the like.

Referring again to FIG. 15 , a plurality of through holes 220h through which a fixing rod 245 ( FIG. 13 , described below in detail) is formed in the cylindrical portion 220B is formed. In this example, six through holes 220h are arranged at equal intervals in the circumferential direction. In this way, in the case where the through hole 220h is formed in the cylindrical portion 220B and the fixing rod 245 passes therethrough, it is advantageous in the following points. That is, according to such a configuration, the cylindrical portion 220B that is a part of the cap 220 holds the fixing rod 245 , and therefore, it is not necessary to separately provide a special structure for holding the fixing rod on the cap member 220 . Therefore, the size reduction of the cap member 220 and the separation membrane module 201 can be achieved, and it also contributes to the weight reduction of the module.

It should be noted that the number of fixing rods 245 is not limited to 6, and may be 1 to 5 or more than 7. As an example, as shown in FIG. 16 , three, four, or eight wires may be used. The material of the fixing rod 245 is not particularly limited, and may be made of metal as an example.

As shown in FIG. 15(B), in the cylindrical portion 220B, a part of the cylindrical portion 220B is cut at a portion where the discharge port 223 opens, and a flat portion 220f is formed. In addition, at the bottom of the cylindrical portion 220B, for example, a flat portion 220g for preventing the separation membrane module from rolling is formed.

As shown in FIG. 13 , an elastic seal member R1 that seals between the tube sheet 230 and the cap member 220 is fitted in the inner peripheral groove 227 a of the cap member. The elastic ring member R1 is configured to remain on the cap member 220 side even when the cartridge 210 is detached from the cap member 220 at the time of replacement. The elastic ring member R1 may be, for example, an O-ring (a substantially circular cross-sectional shape). Alternatively, a V-shaped packing having a substantially V-shaped cross-sectional shape, a U-shaped packing having a substantially U-shaped cross-sectional shape, or the like may be used. Furthermore, the cross-sectional shape may be an ellipse, a rectangle, a polygon, an X shape, or the like.

Between the cylindrical container 211 and the cylindrical portion 220B, another elastic ring member R2 is disposed so as to be fitted in the outer peripheral groove 219 of the cylindrical container 211 , thereby sealing between the two members. As for the elastic ring member R2 , various seals such as O-rings, V-seals, and U-seals can be used as described above.

As shown in FIGS. 13 and 15 , the cap members 220 and 221 are fixed to each other by six (one example) fixing rods 245 and nuts 246 attached to both ends thereof. In the present embodiment, as described above, the cap members 220 and 221 are fixed to each other by a fixing device prepared as another component with respect to the cartridge 210 . Therefore, there is no need to provide a flange or the like for fixing to the side of the case 210 (in particular, the cylindrical member 211 ), and the structure of the case 210 can be simplified.

In addition, the fixing means for fixing the cap members 220 and 221 is not limited to this, Various fixing means can be utilized. For example, one end of the fixed rod may be a large diameter head, and the other end may be fitted with a nut. Alternatively, threads may be threaded on the inner periphery of the through hole 220h of the cap member 220, and threads may also be threaded on the rod end corresponding to this, and the rod end may be screwed into the through hole 220h. Alternatively, another mechanical device that mechanically connects and fixes the cap members may be used, for example, a mechanical device that clamps both ends of the assembly (cap members 220 and 221 ) with a jig.

Furthermore, it is not limited to the mechanical device fixed to each other of the cap members 220, 221, and a mechanical device for fixing each cap member 220, 221 at a predetermined fixed position may be used, and a detachable mechanism may be used between the cap members 220, 221. The mechanism of the box 210 is set up in the same way. For example, a part of the device or facility on which the separation membrane module is mounted functions as a base member (not shown), and a structure in which the cap members 220 and 221 are fixed to the base member can be used.

In the separation membrane module 201 of this embodiment, for example, gas separation is performed by introducing pressurized air into the container through the gas introduction port P1 and sending the air into the hollow fiber membrane 214 from the opening end thereof. internal. While the pressurized air flows in the hollow fiber membrane 214, the oxygen-enriched air selectively permeates outside the membrane, and the permeated oxygen-enriched air moves into the space containing the hollow fiber bundles between the tube sheets (permeation side space). The permeated gas is discharged to the outside from the opening 212 and the opening 223 which are the permeated gas discharge ports. On the other hand, the nitrogen-enriched air that has not permeated is discharged to the outside from the non-permeated gas discharge port P2 that is the non-permeated gas discharge port through the other opening of the hollow fiber membrane 214 .

In the gas separation membrane module 201 described above, the cartridge 210 accommodating the hollow fiber bundle 215 is configured to be replaceably attached between the cap members 220 and 221 . Therefore, at the time of replacement, only the cartridge needs to be replaced, and the whole unit does not need to be replaced, so the cost of replacement parts can be kept down.

On the other hand, it is conceivable to replace only the element corresponding to the inner hollow fiber element 215 , but in this case, a structure for attaching and detaching the replacement part must be built in the cylindrical container 211 . On the other hand, in the module 201, the cylindrical container 211 which is a part of the cartridge 210 directly functions as the main body of the module 201, and thus does not require a complicated structure. This is advantageous for reducing the weight of the separation membrane module 201 as a whole, and can be particularly preferably used in fields where module weight reduction is desired, such as the aerospace field.

Furthermore, the above-mentioned structure is formed by connecting the cap members 220, 221 with the fixing means (245, 246) which are parts different from the case 210. FIG. Therefore, there is no need to form a structural part (for example, a flange part, etc.) for connecting the cap member to the cylindrical container 211 . Therefore, the structure of the cartridge 210 can be simplified, and the manufacturing cost can also be controlled.

In addition, the above configuration is such that the elastic ring member R1 is held on the inner circumference of the cap members 220, 221, and the ring member R1 remains on the cap member side when the cartridge 210 is detached at the time of replacement. Such a configuration is more advantageous for the manufacturing cost of the control box 210 than providing the ring member R1 on the box 210 side.

As shown in FIG. 13, in the structure of this embodiment, since the chamfered surface (tapered surface) is formed along the outer periphery of the end portion of the tube plate 230, the tube plate 230 can be smoothly inserted into the elastic ring member R1. the end of.

As mentioned above, although embodiment of the invention of this part was demonstrated referring drawings, the invention of this part is not limited to the form of illustration, Various changes are possible. For example, the shape and arrangement position of the sealing member for sealing between the members can be appropriately changed. In addition to the elastic ring members R1, R2, additional sealing members may be provided.

As shown in FIG. 13 , in the above-mentioned embodiment, the configuration in which the elastic ring member R2 is fitted on the outer periphery of the cylindrical container 211 was exemplified, but the invention of this part is not limited thereto, and the following configuration may be adopted: the cap member 220 The elastic ring member R2 is provided on the inner periphery of 221, and this elastic ring member R2 remains on the cap member 220, 221 side when the cartridge is replaced. In this case, since the outer peripheral groove 219 does not need to be formed in the cylindrical container 211 of the cartridge 210, the manufacturing cost of the cartridge 211 can be further suppressed.

In the above-mentioned embodiments, an example constituting a separation membrane module of a so-called bore feed type (Bore Feed Type) was exemplified, but the invention of this section can also be applied to a separation membrane module constituting a shell feed type (shell feed type) . In this case, the cartridge corresponding to the shell feed type may be configured to be replaceably attached between the cap members as described above.

(Technical solutions)

The invention relating to Section D is as follows.

1. A gas separation membrane module, comprising:

A box containing hollow fiber bundles composed of many hollow fiber membranes in a cylindrical container;

cap members fitted to both ends of the box;

sealing a sealing member between each of the above-mentioned cap members and the above-mentioned case; and

fixing means for fixing said cap members to each other;

Among them, the cartridge is configured to be replaceably attached between the cap members.

2. The gas separation membrane module according to the above 1, wherein at least one fixing rod for connecting the cap members to each other is provided as the fixing means,

A through hole through which the above-mentioned fixing rod is inserted is formed in each cap member.

3. The gas separation membrane module according to 1 or 2 above, wherein the cap member is attached so as to cover the end of the cylindrical container,

The sealing member is an elastic ring member disposed between the outer periphery of the case and the inner periphery of the cap member.

4. The gas separation membrane module according to 3 above, wherein the elastic ring member is held on the inner periphery of the cap member so as to remain on the cap member side when the cartridge is detached from the cap member during replacement. constitute.

5. The gas separation membrane module according to any one of 1 to 4 above, wherein the cassette has a tube sheet for holding the end of the hollow fiber bundle while isolating the inside and outside of the cylindrical container,

an inner peripheral groove is formed in the interior of the above-mentioned cylindrical container and faces the region of the above-mentioned tube sheet,

A part of the tube sheet is engaged with the inner peripheral groove.

[Part E: Gas Separation Membrane Modules That Can Efficiently Perform Gas Separation]

(technical field)

The invention in this section relates to a gas separation membrane module utilizing a hollow fiber membrane for gas separation, and in particular to a gas separation membrane capable of efficiently implementing gas separation in a so-called bore feed type module components.

(Background technique)

A hollow fiber type gas separation membrane module generally includes a hollow fiber element having a hollow fiber bundle composed of a large number of hollow fiber membranes having selective permeability, and a hollow housing for accommodating the hollow fiber bundle. A hollow fiber bundle of a hollow fiber element is fixed at one or both ends by a cured sheet (tube sheet) of resin. In addition, a mixed gas inlet, a permeated gas outlet, and a non-permeated gas outlet are provided on the box.

For the purpose of effectively separating gases, for example, Japanese Patent Application Laid-Open No. 2000-262838 discloses a gas separation membrane module, which is constituted as follows: a so-called borehole feed is supplied to a mixed gas in a hollow fiber membrane. In the bore feed type module, a part of the hollow fiber bundle is covered with a membrane member, and the hollow fiber membrane is sandwiched by the flow of the carrier gas and the flow of the mixed gas to form convection.

In the gas separation membrane module of the above-mentioned patent document 1, by restricting the flow direction of the carrier gas, the effectiveness of gas separation can be achieved, but it is a bore feed type (bore feed type) and does not use the carrier gas (purge gas). ) in the gas separation membrane module, it is also important to improve the efficiency of gas separation. The present invention was made in view of the above-mentioned problems, and an object thereof is to provide a gas separation membrane module capable of efficiently performing gas separation in a bore feed type module.

The main points of the invention disclosed in this section are as follows.

1. A gas separation membrane module, comprising:

A hollow fiber bundle formed by bundling many hollow fiber membranes with gas separation performance;

a casing having a mixed gas inlet, a permeated gas outlet, and a non-permeated gas outlet, and having the aforementioned hollow fiber bundles disposed therein; and

2 tube sheets for fixing both ends of the above-mentioned hollow fiber bundle;

In the gas separation membrane module, the mixed gas introduced from the mixed gas inlet is supplied into the hollow fiber membrane, and a part of the mixed gas is permeated to perform gas separation, wherein,

(i) There is no structure for supplying purge gas for discharging the permeated gas permeating the hollow fiber membrane,

(ii) A membrane member is further provided which is a gas-impermeable (including a substantially gas-impermeable membrane member) wound on the outer peripheral surface of the hollow fiber bundle, wherein the One end portion is substantially in contact with the tube sheet on the downstream side in the mixed gas supply direction, and the other end portion is arranged so as to be separated from the above-mentioned tube sheet on the upstream side in the mixed gas supply direction.

According to the invention of this part, the flow direction of the permeated gas is controlled by the membrane member wound around the hollow fiber bundle, and it flows in the opposite direction to the supply direction of the mixed gas (details will be described later). Efficient gas separation in bore feed type components.

(Implementation in Part E)

Hereinafter, one embodiment of the invention of this part will be described with reference to the drawings. Fig. 17 is a cross-sectional view schematically showing the basic configuration of the gas separation membrane module of this embodiment.

The gas separation membrane module 601 shown in FIG. 17 is a gas separation membrane module of a bore feed type, and includes: a hollow fiber bundle 615 in which many hollow fiber membranes 614 are bundled; a box for accommodating the hollow fiber bundle body 610; and tube sheets 621, 622 provided at both ends of the hollow fiber bundle 615.

The hollow fiber membrane 614 can be a currently known hollow fiber membrane, and it can be a hollow fiber membrane of any material as long as it has gas separation performance. As an example, a hollow fiber made of a polymer material, especially a polymer material that is glassy at room temperature (23°C) such as polyimide, polysulfone, polyetherimide, polyphenylene ether, and polycarbonate A membrane is preferable because it has good gas separation performance.

The hollow fiber bundle 615 is a hollow fiber bundle obtained by bundling, for example, about 100 to 1,000,000 hollow fiber membranes 614 . The shape of the bundled hollow fiber bundle 615 is not particularly limited, but from the viewpoint of ease of manufacture and pressure resistance of the casing, a cylindrical shape is preferable as an example. In FIG. 17 , the form in which the hollow fiber membranes 614 are substantially arranged in parallel is illustrated, but the form in which the hollow fiber membranes are arranged in a cross direction may also be used.

The gas mixture to be separated by the hollow fiber membrane 614 is not particularly limited, and may be, for example, a gas mixture containing a gas with high permeability and a gas with low permeability in which the ratio of the permeation rate to the separation membrane is 2 or more. The gas separation membrane module 601 of this embodiment can be used to separate a specific gas component from a mixed gas in various ways. For example, dehumidification of various gases, humidification of various gases, enrichment of nitrogen or oxygen, and the like can be performed.

The tube sheets 621 and 622 are provided in a disk shape corresponding to the cross-sectional shape of the box, and the ends of the hollow fiber bundles 615 are fixed while the openings of the hollow fiber membranes 614 are maintained. The tube sheets 621 and 622 may be thermoplastic resins such as polyethylene or polypropylene, or thermosetting resins containing epoxy resins or polyurethane resins. The tube sheets 621 and 622 play the role of integrally fixing many hollow fiber membranes 614 . In addition, it functions to seal between the hollow fiber membranes 614 and between the hollow fiber bundles 615 and the inner surface of the casing 610 . As shown in FIG. 17, a closed space 618 (with a permeated gas discharge port 610c as described later) is formed by the box body 610 and two tube sheets 621 and 622, and the permeated hollow gas is introduced into the closed space 618. The permeable gas of the silk membrane 614. Furthermore, the mixed gas space 619 a is formed by the box body 610 and the tube sheet 621 , and the non-permeable gas space 619 b is formed by the box body 610 and the tube sheet 622 . It should be noted that, in order to seal between the tube sheets 621 , 622 and the inner surface of the box body 610 , other sealing devices may be provided.

It should be noted that, as the epoxy resin used for the tube sheets 621, 622, for example, in the case of a nitrogen membrane module, the epoxy resin described in Japanese Patent Application Publication No. 2-36287 can be used. In the case of separating the module, epoxy resins as described in WO2009/044711 and the like can be used.

As shown in FIG. 17 , the box body 610 is provided in a substantially cylindrical shape as a whole. The box body 610 has a mixed gas inlet 610a for introducing the mixed gas into the box body 610 on the upstream side (the left side of the figure), and a non-permeable gas outlet 610b on the downstream side (the right side of the figure). The section has a permeate gas outlet 610c. The number of permeated gas outlets 610c may be one or multiple. The plurality of permeated gas outlets 610c may be arranged at equal intervals along the side wall of the case 610 . In this example, the permeated gas outlet 610c is formed at a position close to the tube plate 621 on the upstream side (specifically, at a position where there is no exposed portion A1 of the hollow fiber bundle 615 where the membrane member 631 described later exists).

The mixed gas introduced from the mixed gas inlet 610a enters the hollow fiber membranes 614 from the end surface of the tube sheet 621, and flows inside the hollow fiber membranes 614 toward the downstream side. At this time, part of the mixed gas permeates out of the hollow fiber membrane 614, and the permeated gas is sent into the closed space 618, and then is discharged out of the box through the permeated gas outlet 610c. On the other hand, the non-permeated gas that has not passed through the hollow fiber membrane directly flows toward the downstream side in the hollow fiber membrane 614, is sent out of the membrane from the downstream end surface, and then is discharged to the tank via the non-permeated gas outlet 610b. in vitro.

It should be noted that FIG. 17 schematically shows the box body 610 , and specifically, the box body configuration as shown in FIG. 19 may be used. In this example, the case 610 has a cylindrical member 611 with both ends opened, and caps 612 and 613 attached to both ends. The cylindrical member 611 and the caps 612 and 613 may be made of metal, plastic or ceramics as an example. A mixed gas inlet 610 a and a non-permeated gas outlet 610 b are respectively formed on the caps 612 and 613 . As an example, the mixed gas inlet 610a and the non-permeated gas outlet 610b may be formed at the center of the caps 612 and 613 (the center when viewed from the front of the cap).

As shown in FIGS. 17 and 18 , in the gas separation membrane module 601 of this embodiment, the membrane member 631 is wound around the outer periphery of the hollow fiber bundle 615 . The membrane member 631 is arranged such that one end portion 631 a thereof is substantially in contact with the tube sheet 622 and the other end portion 631 b is separated from the tube sheet 621 by a predetermined distance. In FIG. 17 , the area of the hollow fiber bundle 615 not covered with the membrane member 631 is indicated by symbol A1 (exposed portion). The membrane member 631 can be configured to cover 50% to 95%, preferably 75% to 92%, of the outer surface of the hollow fiber bundle. In addition, the membrane member 631 can also be configured as follows: both ends are close to each tube sheet and cover the entire outer surface of the hollow fiber bundle, and one or more holes are opened on the membrane member 631 near the tube sheet 621 .

It should be noted that "substantially abutting" the end of the membrane member refers to: (i) the case where the end of the membrane is completely in contact with the tube sheet; Both cases where the end of the membrane is close to the tube sheet with a slight gap between the tube sheet and the tube sheet are formed. On the other hand, when the tube sheet is made of epoxy resin, etc., when the end of the film enters the tube sheet (for example, when the end of the film is buried in the tube sheet and the tube sheet is cured, etc.), the part may As the starting point, the tubesheet is cracked or damaged. Therefore, it may be preferable to configure so that the end portion of the film does not enter the inside of the tube sheet.

The membrane member 631 may be made of any material as long as it is substantially gas-impermeable. It should be noted that "substantially gas-impermeable" means that the gas permeation of the membrane member 631 is sufficiently small to restrict the gas flow path. For example, plastic films such as polyimide, polyethylene, polypropylene, polyamide, and polyester may be used. Among them, polyimide is preferable in terms of heat resistance, solvent resistance, and workability. Metal foils such as aluminum or stainless steel may be used instead of plastic films. The thickness of the film may be in the range of several tens of μm to several mm. The film member 631 may be formed in a cylindrical shape by fixing side edges of one film to each other, or a cylindrical member without a seam may be used. As means for fixing the films, for example, an adhesive, a tape, or the like can be used.

Assuming that the membrane member 631 is not arranged, as indicated by arrow f3 in FIG. 18 , the permeated gas from the hollow fiber membrane 614 advances in the cross flow direction (ie, the direction crossing the hollow fiber membrane 614 ). On the other hand, when the membrane member 631 is wound around the hollow fiber bundle 615 as in the present embodiment, the permeated gas is prevented from being lost, and as shown by the arrow f2, the direction f1 of the permeated gas relative to the mixed gas supply is flow in the countercurrent direction.

Next, an example of a method of using the separation membrane module of the present embodiment configured as above will be described. It should be noted that the method of using the components of this embodiment is not limited to the following methods.

First, the mixed gas is introduced from the mixed gas inlet 610 a into the mixed gas space 619 a in the casing 610 . The introduced mixed gas enters the hollow fiber membranes 614 from the end surface of the tube sheet 621 and moves downstream therein. At this time, the pressure inside the hollow fiber membrane 614 is preferably higher than the pressure of the closed space 618, for example, it is preferable to supply the mixed gas at a pressure of 0.01 MPaG to 10 MPaG; At this time, part of the mixed gas selectively permeates the hollow fiber membrane 614 and is sent out to the closed space 618 outside the hollow fiber membrane 614 . On the other hand, the non-permeated gas directly flows downstream in the hollow fiber membrane 614 , and is sent out from the downstream end surface to the non-permeated gas space 619 b outside the hollow fiber membrane 614 .

The gas that has passed through the hollow fiber membrane 614 is introduced into the closed space 618 in the casing 610 . As shown in FIG. 18, especially in the area where the membrane member 631 is wound, the function of the membrane member 631 can prevent the loss of the permeated gas, and the permeated gas flows in the direction of the arrow f2 opposite to the supply direction f1 of the mixed gas. flow. Next, the permeated gas is discharged to the outside of the casing 610 through the permeated gas outlet 610c (see FIG. 17 ). The non-permeated gas is sent out from the downstream end of the hollow fiber membrane 614, and then discharged to the outside through the non-permeated gas outlet 610b.

In the separation membrane module 601 described above, the membrane member 631 prevents the permeated gas from being lost, and at the same time, the permeated gas flows in a direction countercurrent to the direction in which the mixed gas is supplied. Therefore, the separation efficiency of gas can be improved.

(Content of invention)

The invention relating to Part E is as follows.

1. A gas separation membrane module, comprising:

A hollow fiber bundle formed by bundling many hollow fiber membranes with gas separation performance;

a housing having a mixed gas inlet, a permeated gas outlet, and a non-permeated gas outlet, and having the aforementioned hollow fiber bundles disposed therein; and

2 tube sheets for fixing the two ends of the above-mentioned hollow fiber bundle;

The mixed gas introduced from the mixed gas inlet is supplied into the hollow fiber membrane, and a part of the mixed gas is permeated to perform gas separation, wherein,

(i) No structure is provided for supplying purge gas for discharging the permeated gas which has permeated the above-mentioned hollow fiber membrane,

(ii) There is further provided a membrane member which is a gas-impermeable membrane member wound on the outer peripheral surface of the hollow fiber bundle, wherein one end thereof is substantially connected to the tube on the downstream side in the mixed gas supply direction. The plates are arranged so that the other end portion is in contact with the above-mentioned tube plate on the upstream side in the mixed gas supply direction.

2. The gas separation membrane module according to the above 1, wherein the one end portion of the membrane member does not penetrate into the inside of the tube sheet.

3. The gas separation membrane module according to the above 1 or 2, wherein the permeated gas outlet is provided in a part of the casing surrounding an exposed portion of the hollow fiber bundle where the membrane member is not present.

4. The gas separation membrane module according to any one of 1 to 3 above, wherein the membrane member is configured to cover the outer surface of the hollow fiber bundle 50 in the region from one of the tube sheets to the other tube sheet. %~95%.

5. The gas separation membrane module according to any one of 1 to 4 above, wherein the material of the membrane member is polyimide.

[Part F: Gas Separation Membrane Module Preventing Gas Leakage from the Gap Between Membrane End and Tube Sheet]

(technical field)

The invention in this part relates to a gas separation membrane module using a hollow fiber membrane for gas separation, and in particular to a method for preventing gas from flowing from between the end of the membrane and the tube sheet in a bore feed type module. A gas separation membrane module in which gas separation can be efficiently performed by leakage of the gap portion.

(Background technique)

A hollow fiber type gas separation membrane module generally includes a hollow fiber element having a hollow fiber bundle composed of a large number of hollow fiber membranes having selective permeability, and a hollow housing for accommodating the hollow fiber element. A hollow fiber bundle of a hollow fiber element is fixed at one or both ends by a cured sheet (tube sheet) of resin. In addition, a mixed gas inlet, a permeated gas outlet, and a non-permeated gas outlet are provided on the box.

For the purpose of efficiently separating gases, for example, Japanese Patent Application Laid-Open No. 2000-262838 discloses a gas separation membrane module in which a so-called borehole feed type (bore-feeding type) is used to supply a mixed gas into a hollow fiber membrane. Feed Type) module, a part of the hollow fiber bundle is covered with a membrane member, and the hollow fiber membrane is sandwiched by the flow of the carrier gas and the flow of the mixed gas to form a convection flow.

In the gas separation membrane module of the above document, the efficiency of gas separation can be achieved by restricting the flow direction of the carrier gas, but in the gas separation membrane module that does not use the carrier gas (purge gas), it is also important to improve the efficiency of gas separation of. On the other hand, regardless of the use of the purge gas, it is effective to prevent gas leakage from the gap between the membrane end and the tube sheet (details will be described later) in order to further enhance gas separation.

The invention of this part is made in view of the above-mentioned problems, and its object is to provide a gas separation membrane module which, in a bore feed type module, prevents gas from flowing from the membrane end and The gap between the tube sheets leaks out, enabling efficient gas separation.

The main points of the invention disclosed in this section are as follows.

1. A gas separation membrane module, comprising:

A hollow fiber bundle formed by bundling many hollow fiber membranes with gas separation performance;

A box with a mixed gas inlet, a permeated gas outlet and a non-permeated gas outlet, and the above-mentioned hollow fiber bundle inside;

2 tube sheets for fixing the two ends of the above-mentioned hollow fiber bundle;

A gas-impermeable (including substantially gas-impermeable membrane member) membrane member wound on the outer peripheral surface of the above-mentioned hollow fiber bundle, wherein one end of the membrane member is connected to the downstream side of the mixed gas supply direction. The tube sheet is arranged so that the other end portion is away from the tube sheet on the upstream side in the mixed gas supply direction; and

A sealing structure for sealing a gap between the one end portion of the film member and the tube sheet.

According to the invention of this section, it is possible to provide a gas separation membrane module which, in a bore feed type module, prevents gas from passing through the gap between the membrane end and the tube sheet. Leakage enables efficient gas separation.

(implementation in section F)

Next, one embodiment of the invention of this part will be described with reference to the drawings. In addition, in FIG. 21, the shape of a box (details are mentioned below) is shown more concretely as an example.

The gas separation membrane module (hereinafter referred to simply as the module) 801 shown in Fig. 20 and Fig. 21 includes: a hollow fiber bundle 815 bundled with a plurality of hollow fiber membranes 814, a box body 810 for accommodating the hollow fiber bundle, and a Tube plates 821 and 822 at both ends of 815 . This module 801 is a so-called bore feed type module, and a mixed gas (raw material gas) is supplied to the inside of the hollow fiber membrane 814 .

As the hollow fiber membrane 814, a conventionally known hollow fiber membrane can be used, and any material can be used as long as it has gas separation performance. As an example, a hollow fiber made of a polymer material, especially a polymer material that is glassy at room temperature (23°C) such as polyimide, polysulfone, polyetherimide, polyphenylene ether, and polycarbonate A membrane is preferable because it has good gas separation performance.

The hollow fiber bundle 815 is a hollow fiber bundle obtained by bundling, for example, about 100 to 1,000,000 hollow fiber membranes 814 . The shape of the bundled hollow fiber bundles is not particularly limited, but from the viewpoint of ease of manufacture and pressure resistance of the container, as an example, a cylindrical shape is preferable. In addition, although the form in which the hollow fiber membranes 814 are substantially parallel is shown in FIG. 20, it may be the form in which each hollow fiber membrane is arranged in cross.

The mixed gas separated by the hollow fiber membrane 814 is not particularly limited, and may be, for example, a gas mixture containing a gas with high permeability and a gas with low permeability in which the ratio of the permeation rate to the separation membrane is 2 or more. The gas separation membrane module 801 of this embodiment can be used to separate a specific gas component from a mixed gas in various ways. For example, dehumidification of various gases, humidification of various gases, enrichment of nitrogen or oxygen, and the like can be performed.

The tube plates 821 and 822 correspond to the shape of the case 810 and are provided in a substantially disk shape, and fix the ends of the hollow fiber bundles 815 while maintaining the openings of the hollow fiber membranes 814 . The tube sheets 821 and 822 may be thermoplastic resins such as polyethylene or polypropylene, or thermosetting resins containing epoxy resins or polyurethane resins. The tube sheets 821 and 822 play the role of fixing many hollow fiber membranes 814 integrally. In addition, it functions to seal between the hollow fiber membranes 814 and between the hollow fiber bundles 815 and the inner surface of the casing 810 . As shown in FIG. 20, a closed space 818 (with a permeated gas discharge port 810c as described later) is formed by the box body 810 and two tube sheets 821 and 822, and the permeated hollow gas is introduced into the closed space 818. The permeable gas of the silk membrane 814. Furthermore, the mixed gas space 819 a is formed by the box body 810 and the tube sheet 821 , and the non-permeable gas space 819 b is formed by the box body 810 and the tube sheet 822 . It should be noted that, in order to seal between the tube sheets 821 , 822 and the inner surface of the box body 810 , other sealing devices may also be provided.

It should be noted that, as the epoxy resin used for the tube sheets 821 and 822, for example, in the case of a nitrogen membrane module, the epoxy resin described in Japanese Patent Application Publication No. 2-36287 can be used. In addition, in the case of organic vapor In the case of separating the module, epoxy resins as described in WO2009/044711 and the like can be used.

As shown in FIG. 20 , the box body 810 is provided in a substantially cylindrical shape as a whole. The box body 810 has a mixed gas inlet 810a for introducing the mixed gas into the box body 810 on the upstream side (left side of the figure), and a non-permeated gas outlet 810b on the downstream side (right side of the figure). It has a permeate gas outlet 810c. The number of permeated gas outlets 810c may be one or multiple. The plurality of permeated gas outlets 810c may be arranged at equal intervals along the side wall of the case 810 . In this example, the permeated gas outlet 810c is formed at a position close to the tube plate 821 on the upstream side (specifically, at a position where there is no exposed portion A1 of the hollow fiber bundle 815 where the membrane member 831 described later is present).

The mixed gas introduced from the mixed gas inlet 810a enters the hollow fiber membranes 814 from the end surface of the tube sheet 821, and flows inside the hollow fiber membranes 814 toward the downstream side. At this time, a part of the mixed gas permeates outside the hollow fiber membrane 814, and the permeated gas is sent into the closed space 818, and then is discharged out of the box through the permeated gas outlet 810c. On the other hand, the non-permeated gas that has not passed through the hollow fiber membrane directly flows toward the downstream side in the hollow fiber membrane 814, is sent out of the membrane from the downstream end surface, and then is discharged to the tank via the non-permeated gas outlet 810b. in vitro.

It should be noted that, the mixed gas inlet 810a and/or the non-permeated gas outlet 810b can be arranged such that the central axis thereof coincides with the central axis of the box body 810 (that is, the central axis of the hollow fiber bundle 815 ). In addition, as shown in the example of FIG. 21(A), the box body 810 may have a cylindrical member 811 and tube sheet holding members 813 (one of which is not shown) attached to both ends thereof. The connecting portion of the cylindrical member 811 and the tube sheet holding member 813 may be welded. As an example, the inner peripheral surface of the tube sheet holding member 813 includes a straight line portion 813a with a constant diameter, a large diameter portion 813b with a larger diameter than the straight line portion 813a, and a tapered portion 813c with a gradually smaller diameter. It should be noted that, as shown in FIG. 21(A) , the tube sheet 822 has a hollow fiber membrane embedded portion 822a where the hollow fiber membrane 814 exists, and a non-stained portion 822b around which the hollow fiber membrane 814 does not exist.

As shown in FIGS. 20 and 21 , in the gas separation membrane module 801 of this embodiment, the membrane member 831 is wound around the outer peripheral surface of the hollow fiber bundle 815 . The membrane member 831 is arranged such that one end 831 a (also referred to as a membrane end 831 a ) is close to the tube sheet 822 and the other end 831 b is separated from the tube sheet 821 by a predetermined distance. In FIG. 20 , a region of the hollow fiber bundle 815 not covered with the membrane member 831 is indicated by symbol A1 (exposed portion). The membrane member 831 can be configured to cover 50% to 95%, preferably 70% to 92%, of the outer surface of the hollow fiber bundle. In addition, the membrane member 831 may be configured such that both ends are close to the tube sheets and cover the entire outer surface of the hollow fiber bundle, and one or more holes are opened in the membrane member 831 near the tube sheet 821 .

The membrane member 831 may be made of any material as long as it is made of substantially gas-impermeable material. In addition, "substantially gas-impermeable" means that the gas permeation of the membrane member is sufficiently small so that the flow path of gas can be restricted. For example, plastic films such as polyimide, polyethylene, polypropylene, polyamide, and polyester may be used. Among them, polyimide is preferable in terms of heat resistance, solvent resistance, and workability. Metal foils such as aluminum or stainless steel may be used instead of plastic films. The thickness of the film may be in the range of several tens of μm to several mm.

The film member 831 may be formed in a cylindrical shape by fixing side edges of one film, or a cylindrical member without a seam may be used. As means for fixing the side edges of the film, for example, an adhesive, tape, or the like can be used.

It should be noted that, for example, when the tube sheet is made of epoxy resin, when the end of the film enters the tube sheet (for example, when the end of the film is embedded in the tube sheet material and cured, etc.), the part may be As the starting point, the tubesheet is cracked or damaged. Therefore, in the present embodiment, the membrane end is configured so as not to be embedded in the tube sheet. On the other hand, in such a configuration, as shown in FIG. 21 , a gap A31 may be formed between the membrane end 831a and the tube sheet 822 (for illustration, the size of the gap A31 is exaggerated for description).

As shown in FIGS. 20 and 21 , in this embodiment, a sealing structure 850 for sealing the gap A31 between the film end 831 a and the tube sheet 822 is provided. In this example, the sealing structure 850 is disposed on both sides of the membrane so as to sandwich the membrane 831a, and has two cylindrical sealing bands 851 and 853 formed to surround the hollow fiber bundle 815 (see FIG. 21 ).

Both the seal tapes 851 and 853 are formed of a material permeable to a liquid resin material (epoxy as an example), in other words, a material having a predetermined capillary force. The seal tapes 851 and 853 may be any material as long as they have such a function, for example, a mesh material (for example, a cloth-like or net-like material) made by weaving fibers may be used. The fibers may be, for example, chemical fibers or natural fibers, and glass fibers, carbon fibers, or the like may be used.

As shown in FIG. 21 , the first seal tape 851 is arranged on the outer peripheral surface of the film member 831 , and the second seal tape 853 is arranged on the inner peripheral surface of the film member 831 . Each of the seal bands 851 and 853 is arranged so as to extend from the membrane end portion 831a to the tube sheet 822 side. An extended portion of each of the sealing tapes 851 and 853 is buried in the clean portion 822b in the tube sheet 822 .

As shown in FIG. 21(A) , a fixing tape 855 for fixing the seal tape 851 to the film member 831 is attached to the first seal tape 851 . As an example, the fixing tape 855 may be attached so as to reciprocate once on the outer periphery of the hollow fiber bundle 815 . The fixing tape 855 may be wound twice or more, or the fixing tape 855 may be attached only to a part of the outer periphery.

As shown in FIG. 21(B), the overlapping portion of the two seal tapes 851 and 853 can be fixed with a fixing device 857 . The fixing device 857 may be, for example, a device that mechanically fixes both members, or may be, for example, a needle of a stapler. In addition, wires, metal wires, etc. can also be used, for example.

As will be described later, the seal tapes 851 and 853 have a function of preventing permeated gas from leaking through the gap portion A31. In order to efficiently prevent leakage, a region facing at least the gap portion A31 among the seal tapes 851 and 853 is in a state where the resin material is permeated and cured. Thereby, gas impermeability is imparted to the sealing tapes 851 and 853, and as a result, leakage of gas can be further prevented. It should be noted that the above-mentioned processing may be performed on only one of the two seal tapes 851 and 853 .

The membrane member 831 and the sealing structure 850 can be fabricated as follows, for example. In addition, the following process is a simple example, and the invention of this part is not limited to the order of this process etc. at all.

First, a hollow fiber bundle 815 and a casing (for example, the material shown in FIG. 21 ) are prepared. In addition, one film member 831 formed into a predetermined size is prepared, and at the same time, the sealing tapes 851, 853 are overlapped on both sides of the film so as to sandwich the vicinity of the end portion 831a, and the sealing tapes 851, 853 are fixed with a stapler (an example). the overlapping portion.

Next, the membrane member 831 in this state is wound around the hollow fiber bundle 815 and fixed with, for example, an adhesive tape (not shown). Then, the hollow fiber bundle 815 is arranged at a predetermined position in the casing 810 , and the tube sheets 821 and 822 are formed at both ends of the hollow fiber bundle 815 . The tube sheets 821, 822 can be formed by filling the ends of the hollow fiber bundles 815 with an epoxy material and curing them.

A concrete description will be given using an example in FIG. 21 . As an example, the filling of the epoxy material is carried out in a state where the box 810 into which the hollow fiber bundle 815 enters is held in a vertical direction and a mold (not shown) is attached to the lower end of the box. At this time, as shown in FIG. 21(A), the liquid level of the filled epoxy material is set at a position where the tips of the sealing tapes 851, 853 are embedded in the tube plate 822 but the end portion 831a is not embedded. When the end portions of the seal tapes 851 and 853 are impregnated with the epoxy material, the epoxy material is permeated into the seal tapes 851 and 853 (including at least the region facing the gap A31 ) by capillary force.

Then, the hollow fiber membrane 814 is opened by cutting the solidified tube sheet 822 at a predetermined position, which has solidified the tube sheet material. Next, if necessary, the same assembly process as the conventional process (for example, a process for completing the housing 810, etc.) is performed to complete the assembly.

It should be noted that the membrane member 831 and the sealing tapes 851 and 853 can be arranged in the following order: first, the second sealing tape 853 is wound around the hollow fiber bundle 815, then the membrane member 831 is wound, and then the second sealing tape 853 is wound. 1 sealing tape 851 .

Next, an example of a method of using the separation membrane module of the present embodiment configured as above will be described. It should be noted that the method of using the components of this embodiment is not limited to the following methods.

First, the mixed gas is introduced from the mixed gas inlet 810 a into the mixed gas space 819 a in the casing 810 . The introduced mixed gas enters the hollow fiber membranes 814 from the end surface of the tube sheet 821 and moves downstream therein. At this time, the pressure inside the hollow fiber membrane 814 is preferably higher than the pressure of the closed space 818, for example, it is preferable to supply the mixed gas at a pressure of 0.01 MPaG to 10 MPaG; At this time, part of the mixed gas selectively permeates the hollow fiber membrane 814 and is sent out to the closed space 818 outside the hollow fiber membrane 814 . On the other hand, the non-permeated gas directly flows in the hollow fiber membrane 814 toward the downstream side, and is released from the downstream end surface into the non-permeated gas space 819 b outside the hollow fiber membrane 814 .

Assuming that no membrane member 831 is arranged, as shown by the arrow f3 in FIG. 21(B), the advancing direction of the permeated gas from the hollow fiber membrane 814 is the cross flow direction (that is, the direction crossing the hollow fiber membrane 814) . Alternatively, as indicated by f4, the advancing direction of the permeated gas is the co-current direction of the flow opposite to f2, and furthermore, the flow of f3. On the other hand, when the membrane member 831 is wound around the hollow fiber bundle 815 as in the present embodiment, the loss of the permeated gas can be prevented, and the permeated gas is indicated by an arrow f2 that flows countercurrently to the supply direction f1 of the mixed gas. The direction of flow, as a result, can improve the efficiency of gas separation. In particular, in this embodiment, the sealing structure 850 for sealing the gap A31 is provided, so that permeated gas can be prevented from leaking to the outside through the gap A31. Therefore, the loss of permeated gas can be prevented more reliably, and the efficiency of gas separation can be performed more favorably.

The prevention of leakage of the permeated gas can be achieved by making the membrane end 831a directly embedded in the tube sheet 822. At this time, as described above, the tube sheet 822 may be cracked or cracked starting from the vicinity of the membrane end 831a. damage. On the other hand, in the present embodiment, the sealing tapes 851 and 853 which are members different from the membrane member 831 are buried. Therefore, by appropriately selecting the material of the sealing tapes, it is possible to prevent such breakage or damage of the tube sheet 822. .

As described above, even if the seal tapes 851 and 85 are made of mesh material, leakage of permeated gas can be suppressed compared to the case where no seal tape is provided. However, in the present embodiment, further, the resin material impregnates the sealing tapes 851 and 853 and solidifies there, so that leakage of the permeated gas can be more reliably prevented.

(Other implementations)

As mentioned above, although one form of the invention of this part was demonstrated, the invention of this part is not limited to the said content, Various changes are possible.

For example, only one of the first and second seal tapes 851 and 853 may be used. In addition, the fixing tape 855 for fixing the first seal tape 851 to the film member 831 may be omitted. In addition, the fixing device 857 (refer FIG. 21(B)) which fixes the overlapping part of two seal tapes 851 and 853 can also be omitted.

Fig. 22 shows other sealing ring structures, Fig. 22(A) is a schematic sectional view of the whole assembly, and Fig. 22(B) is a partially enlarged view thereof. In this example, for the sealing structure, a filler 891 arranged to fill the gap A31 between the membrane member 831 and the tube sheet 822 is exemplified. The filler 891 may be, for example, a resin material injected so as to surround the film member 831 (heat-resistant silicone, for example). Such a filler 891 can also prevent permeated gas from leaking from the gap A31, and as a result, a module capable of effective gas separation can be obtained. The filling material 891 can be formed, for example, by forming one or more holes in the side wall of the box after forming the tube sheet 822 in the box, injecting the filling material 891 through the holes and curing it.

The places where such fillers 891 are installed are not limited to those shown in FIG. 22 . For example, as shown in FIG. 23 , a filler 893 may be disposed between the film member 831 and the case 810 at a position separated from the gap A31 by a predetermined distance. As shown in FIG. 23 , the filling material 893 may be arranged at one place in the longitudinal direction of the film member 831 . Such a filling material 893 is disposed in such a manner as to block the flow of gas and to reciprocate once on the outer periphery of the membrane member 831, and its width may be, for example, about 3 mm to 5 mm (for example, 0.5 mm of the outer surface of the membrane). %)above.

Or, the filling material that reciprocates one week on the outer periphery of the film member 831 can be filled in a wider (long) range in the manner of filling the gap between the film member 831 and the box body 810, for example, can account for the covering film member. 10% or more of the outer surface.

In addition, as shown in FIG. 24, the gas separation membrane module of the invention of this section may have a structure for flowing the purified gas. This gas separation membrane module includes a hollow fiber bundle 915, a casing 910, two tube plates 921, 922 for fixing both ends of the hollow fiber bundle 915, and a gas-impermeable membrane wound around the outer peripheral surface of the hollow fiber bundle. The member 931 and the sealing structure 950 that seals the gap between the end of the film member 931 and the tube sheet 922 . The gas separation membrane module also includes a core tube 971 for transporting the purified gas.

20, the case 910 has a mixed gas inlet 910a on the upstream side (left side in the drawing), and a permeated gas outlet 910c on the side wall. The structure on the downstream side of the tube plate 922 is slightly different from that of the module in FIG.

The core tube 971 is a member in which one of both ends is closed and the other is opened, and the opening is arranged in a direction toward the downstream side (tube plate 922 side). The core pipe 971 extends through the tube sheet 922 , and its front end portion is embedded in the tube sheet 921 on the upstream side. The core tube 971 has a hole 971a in a region that becomes between the two tube sheets 921 and 922 .

For an assembly constructed as above, the basic principles of gas separation are the same as for the assembly of FIG. 20 . The purge gas is supplied from the opening of the core pipe 971 (purge gas inlet 910 d ), and the purge gas is discharged into the sealed space 918 in the case 910 through the hole 971 a. The purge gas flows between the hollow fiber membranes 914 in the f2 direction (the direction opposite to the direction in which the mixed gas is supplied), and squeezes the permeated gas released into the same space to the permeated gas outlet 910c side, thereby promoting permeation. Exhaust gas.

Also in a module using such a purge gas, it is preferable to provide a sealing structure 950 that seals the gap between the membrane member 931 and the tube sheet 922 . The sealing structure 950 may also use any one of the above-mentioned various structures. This prevents the permeated gas and the purge gas from leaking from the gap, and makes the permeated gas and the purge gas flow in the f2 direction satisfactorily. As a result, gas separation can be further improved.

(Content of invention)

The invention relating to Section F is as follows.

1. A gas separation membrane module, comprising:

A hollow fiber bundle formed by bundling many hollow fiber membranes with gas separation performance;

A box with a mixed gas inlet, a permeated gas outlet and a non-permeated gas outlet, and the above-mentioned hollow fiber bundle inside;

2 tube sheets for fixing the two ends of the above-mentioned hollow fiber bundle;

A gas-impermeable membrane member wound on the outer peripheral surface of the hollow fiber bundle, wherein one end of the membrane member is close to the tube sheet on the downstream side in the mixed gas supply direction and the other end is upstream in the mixed gas supply direction The side of the above tube sheet is configured in such a way that it leaves; and

A sealing structure that seals a gap between the one end portion of the membrane member and the tube sheet.

2. The gas separation membrane module according to the above 1, wherein the sealing structure has a sealing tape wound on the radially inner or outer side of the membrane member at the one end portion of the membrane member, and The end portion extends toward the tube sheet side, and a part of the extension is embedded in the tube sheet.

3. The gas separation membrane module according to the above 2, wherein, as the sealing band, there are a first sealing band and a second sealing band,

The first sealing tape is formed of a material permeable to a liquid resin material, and is wound on the radially outer side of the film member;

The second seal tape is formed of a material permeable to a liquid resin material, and is wound radially inward of the film member.

4. The gas separation membrane module according to the above 2 or 3, wherein the sealing tape is a mesh material.

5. The gas separation membrane module according to 3 or 4 above, wherein the resin material is impregnated and cured in at least a region of the sealing tape facing the gap, thereby sealing the gap.

6. The gas separation membrane module according to the above 3, wherein the sealing structure further includes a fixing tape for fixing the first sealing tape to the membrane member.

7. The gas separation membrane module according to the above 3, wherein the above-mentioned sealing structure further has a fixing device for fixing the extension part of the first sealing band extending from the above-mentioned one end of the membrane member and the extension part from the first end of the membrane member. An extension portion of the second seal tape extending from the one end portion of the film member.

8. The gas separation membrane module according to the above 1, wherein the sealing structure has a filler arranged to fill the gap between the one end of the membrane member and the tube sheet.

9. The gas separation membrane module according to any one of 1 to 8 above, which is configured such that the one end portion of the membrane member does not enter the interior of the tube sheet.

10. The gas separation membrane module according to any one of 1 to 9 above, wherein the material of the membrane member is polyimide.

[Part G: Gas Separation Membrane Module Ensuring Sufficient Sealing Performance Around Tube Sheet]

(technical field)

The present invention relates to a gas separation membrane module using a hollow fiber membrane for gas separation, in particular to a gas separation membrane module, etc. The sealing performance around the tube sheet can be sufficiently ensured, and it can be used favorably at high temperatures.

(Background technique)

A hollow fiber type gas separation membrane module generally includes a hollow fiber element having a hollow fiber bundle composed of a large number of hollow fiber membranes having selective permeability, and a hollow housing for accommodating the hollow fiber element. One or both ends of the hollow fiber bundle are fixed with a cured sheet (tube sheet) of resin.

Generally, the higher the temperature and pressure of the gas supplied to the gas separation membrane, the greater the gas permeation rate. Therefore, when a gas separation membrane module is used, it may be considered to supply the raw material gas to the module after being compressed by a compressor or the like. This compressed gas may be about 149° C. to 260° C. depending on circumstances.

However, there is a problem that in the case of a module that separates the high-temperature mixed gas as described above, it is necessary to use a heat-resistant tube sheet material, but such a tube sheet material is generally easy to solidify and shrink when it is cured, As a result, the sealing performance around the tube sheet may be insufficient. The invention of this section was made in view of this point, and its object is to provide a separation membrane module, etc., which can sufficiently secure the tube sheet even when using a tube sheet material that is relatively easy to cure and shrink. Peripheral sealing performance, and thus can be used well at high temperature.

The main points of the invention disclosed in this section are as follows.

A gas separation membrane module according to one aspect of the invention of this part has:

A hollow fiber bundle formed by bundling many hollow fiber membranes with gas separation performance;

a housing having the hollow tows disposed therein; and

a tube sheet securing at least one end of said hollow fiber bundle;

The gas separation membrane module is configured such that the outer peripheral surface of the tube sheet is not bonded to the inner peripheral surface of the casing,

Wherein, the gas separation membrane module further includes a sealing member that seals between the outer peripheral surface of the tube sheet and the inner peripheral surface of the case.

In addition, a method for manufacturing a gas separation membrane module according to an aspect of the invention of this section, the gas separation membrane module includes: a hollow fiber bundle in which a plurality of hollow fiber membranes having gas separation performance are bundled; A box body for a bundle, and a tube sheet for fixing at least one end of the above-mentioned hollow fiber bundle, wherein the manufacturing method includes the following steps:

A step of applying a mold release agent on at least the part where the tube sheet is in contact with the inner peripheral surface of the above-mentioned box,

A step of filling a part of the above box with a thermosetting resin,

the step of forming the above-mentioned tube sheet by curing the above-mentioned thermosetting resin, and

A step of providing a sealing member between the outer peripheral surface of the tube sheet and the inner peripheral surface of the box after the thermosetting resin is cured.

In addition, the definition of the term in this specification is as follows.

"High temperature condition" or "high temperature" means, for example, within the range of 80°C to 300°C.

The "cylindrical container" is not limited to a container that is open at both ends, but also includes a container that is open at only one end.

According to the invention of this section, it is possible to provide a gas separation membrane module, etc., which can sufficiently ensure the sealing performance around the tube sheet even when using a tube sheet material that is relatively easy to cure and shrink, and furthermore, Even at high temperatures, it can be used well.

(implementation in section G)

Next, one embodiment of the invention of this part will be described with reference to the drawings. In addition, in FIG. 25, the shape of a box (details are mentioned later) is shown more concretely as an example. In addition, the configuration described below is a configuration showing an example in the final analysis, and the gas separation membrane module of the present invention is not limited to these configurations.

The gas separation membrane module (hereinafter also simply referred to as the module) 1001 shown in Fig. 25 and Fig. 26 includes: a hollow fiber bundle 1015 in which many hollow fiber membranes 1014 are bundled; a box 1010 for accommodating the hollow fiber bundle; Tube sheets 1021 and 1022 are provided at both ends of the filament bundle 1015 . As an example, this module 1001 is a so-called bore feed type module, and a mixed gas (raw material gas) is supplied to the inside of the hollow fiber membrane 1014 .

The hollow fiber membrane 1014 can be a currently known hollow fiber membrane, and it can be a hollow fiber membrane of any material as long as it has gas separation performance. As an example, a hollow fiber made of a polymer material, especially a polymer material that is glassy at room temperature (23°C) such as polyimide, polysulfone, polyetherimide, polyphenylene ether, and polycarbonate The membrane is preferable because of its good gas separation performance.

The hollow fiber bundle 1015 is a hollow fiber bundle obtained by bundling, for example, about 100 to 1,000,000 hollow fiber membranes 1014 . The shape of the bundled hollow fiber bundle 1015 is not particularly limited, but from the viewpoint of easiness of manufacture and pressure resistance of the container, a cylindrical shape is preferable as an example. In addition, although the form in which the hollow fiber membranes 1014 are substantially parallel is shown in FIG. 25, the form in which each hollow fiber membrane is arranged crosswise may be sufficient.

The gas mixture to be separated by the hollow fiber membrane 1014 is not particularly limited, and may be, for example, a gas mixture containing a gas with high permeability and a gas with low permeability in which the ratio of the permeation rate to the separation membrane is 2 or more. The gas separation membrane module 1001 of this embodiment can be used to separate a specific gas component from a mixed gas in various ways. For example, dehumidification of various gases, humidification of various gases, enrichment of nitrogen or oxygen, and the like can be performed.

The tube plates 1021 and 1022 are formed in a substantially disk shape corresponding to the shape of the casing 1010 (details are described below), and the ends of the hollow fiber bundles 1015 are fixed while maintaining the openings of the hollow fiber membranes 1014 . The tubesheet serves in this example to seal the hollow fiber membranes from each other. The tube sheet can also be a thermoplastic resin such as polyethylene or polypropylene, or a thermosetting resin containing epoxy resin or polyurethane resin. Next, an example in which the tube sheet is made of a thermosetting resin will be described.

It should be noted that, as the epoxy resin used for the tube sheets 1021 and 1022, for example, in the case of nitrogen membrane modules, epoxy resins such as those described in Japanese Patent Application Publication No. 2-36287 can be used. In the case of separating the module, epoxy resins as described in WO2009/044711 and the like can be used.

As shown in FIG. 25, in this embodiment, a closed space 1018 is formed by the box body 1010 and two tube plates 1021 and 1022 (as described later, it has a permeated gas discharge port 1010c), and in this closed space 1018 The permeated gas that has permeated through the hollow fiber membrane 1014 is introduced therein. Furthermore, a mixed gas space 1019 a is formed by the box body 1010 and the tube sheet 1021 , and a non-permeable gas space 1019 b is formed by the box body 1010 and the tube sheet 1022 .

As shown in FIG. 25 , the box body 1010 is provided in a substantially cylindrical shape as a whole. The box body 1010 has a mixed gas inlet 1010a for introducing mixed gas into the box body 1010 on the upstream side (left side of the figure), and a non-permeable gas outlet 1010b on the downstream side (right side of the figure). It has a permeate gas outlet 1010c. The number of permeated gas outlets 1010c may be one or plural. A plurality of permeated gas outlets 1010c may be arranged at equal intervals along the side wall of the case 1010 .

The mixed gas introduced from the mixed gas inlet 1010a enters the hollow fiber membranes 1014 from the end surface of the tube sheet 1021, and flows inside the hollow fiber membranes 1014 toward the downstream side. At this time, part of the mixed gas is the permeated gas that has permeated outside the hollow fiber membrane 1014, and this permeated gas is sent into the closed space 1018, and then is discharged out of the box through the permeated gas outlet 1010c. On the other hand, the non-permeated gas that has not passed through the hollow fiber membrane directly flows downstream in the hollow fiber membrane 1014, is sent out of the membrane from the downstream end surface, and then is discharged to the box through the non-permeated gas outlet 1010b. outside.

It should be noted that, the mixed gas inlet 1010 a and/or the non-permeated gas outlet 1010 b can be arranged such that the central axis thereof coincides with the central axis of the box body 1010 (ie, the central axis of the hollow fiber bundle 1015 ). In addition, as shown in the example of FIG. 26, the case 1010 may have the cylindrical member 1011 and the cap member 1012 attached to the both ends (one is not shown). The cylindrical member 1011 and the cap member 1012 may be made of metal as an example.

Specifically, the cylindrical member 1011 is a hollow member having an inner diameter _d0 , and thick portions 1011a, 1011b are formed at the ends thereof. The first thick portion 1011a is provided near the end surface of the cylindrical member 1011, and the inner diameter of this portion is formed to be smaller than the inner diameter _d0 . The second thick portion 1011b is provided on the inner side in the axial direction than the first thick portion 1011a, and the inner diameter of this portion is also formed to be smaller than the inner diameter _d0 . The inner diameter of the portion between the thick portion 1011a and the thick portion 1011b is larger than the inner diameters of both the thick portions 1011a, 1011b, and may be d ₀ as an example.

Corresponding to such a structure of the cylindrical member 1011, the tube sheet 1021 is formed in the following shape. That is, as shown in FIG. 26 , the tube plate 1021 has three parts (first part 1021a, second part 1021b, and third part 1021c in order from the outer side) having different diameters in a broad sense. Among them, the diameter of the middle part 1021b is Set it for maximum mode. In this example, the boundary between the first portion 1021a and the second portion 1021b is a tapered surface. In addition, the boundary between the second portion 1021b and the third portion 1021c is a straight surface (a surface extending in a direction perpendicular to the central axis of the cylindrical member).

When the separation membrane module 1001 is used, a force is applied to the tube sheet 1021 in a direction in which the tube sheet is pushed into the cylindrical member 1011 by the pressure of the mixed gas. However, according to the structure shown in FIG. 26, a part of the tube plate 1021 abuts against the thick portion 1011b, thereby restricting the movement of the tube plate 1021, so that the tube plate 1021 does not squeeze into the inside.

In addition, although it does not limit, R shape may be provided in the connection part 1021f of the 2nd part 1021b of a tube sheet, and the 3rd part 1021c. Thereby, the stress concentration in this part can be alleviated, and the breakage of a tube sheet, etc. can be prevented.

The example in FIG. 26 shows a state where the tube sheet 1021 is made of a thermosetting resin, and the diameter of the tube sheet 1021 is slightly shrunk due to curing shrinkage. In the case of such a configuration, there is a possibility that the seal between the tube plate 1021 and the cylindrical member 1011 cannot be sufficiently ensured. Therefore, in this embodiment, an annular sealing member 1060 is provided for sealing between the two members. .

As shown in FIG. 26, an annular step portion 1021s is formed on the outer peripheral portion of the first portion 1021a of the tube sheet. The stepped portion 1021s cooperates with the inner peripheral surface of the cylindrical member 1011 to integrally form an annular groove C1, and an annular sealing member 1060 is arranged in the groove C1.

The sealing member 1060 is an annular part formed of an elastic member, and may be a part (for example, an O-ring, etc.) fitted into the groove C1. Alternatively, a resin material for sealing may be filled in the recess C1 and the resin material is cured to function as a sealing member. The cross-sectional shape of the O-ring can be circular or elliptical. The "annular part made of an elastic member" may be a V-seal having a substantially V-shaped cross-sectional shape, a U-seal having a substantially U-shaped cross-sectional shape, or the like in addition to an O-ring. Furthermore, for example, it may be a component having a cross-sectional shape such as a rectangle, a polygon, or an X shape. It should be noted that, in the example of FIG. 26 , the sealing member 1060 seals between the tube sheet 1021 and the box body 1010 , and also seals between the tube sheet 1021 and the cap member 1012 .

In addition, the structure shown in FIG. 26 is an example at all, and does not limit the invention of this part at all. For example, the first portion 1021a and the third portion 1021c of the tube sheet may have the same diameter. Alternatively, a tube sheet composed of the first portion 1021a and the third portion 1021c may be used. In addition, the surface between the first portion 1021a and the second portion 1021b may not be a tapered surface as shown in FIG. 26 but a straight surface. Similarly, the surface between the second portion 1021b and the third portion 1021c may not be a straight surface as shown in FIG. 26 but a tapered surface. Furthermore, the sealing member 1060 seals between the tube sheet 1021, the box body 1010, and the cap member 1012, but it may be different from the sealing member between the tube sheet 1021 and the box body 1010, and may be provided with a space between the box body 1010 and the cap member 1012. The sealing member between.

Fig. 27 is a sectional view taken along line A-A of Fig. 26 . As shown in the figure, recessed parts 1011d and 1011d may be formed at two places on the inner peripheral surface of the cylindrical member 1011 . At this time, the tube sheet member enters into the recesses 1011d and 1011d to be cured (details will be described later), and as a result, rotation of the tube sheet 1021 can be prevented. It should be noted that the number of the recesses 1011d is not particularly limited, and may be only one, or three or more.

An example of a method of manufacturing the gas separation membrane module 1001 configured as described above may be the following method. That is, the manufacturing method of the present embodiment includes the following steps:

(a) a step of applying a release agent on at least the part where the tube sheet meets the inner peripheral surface of the tank;

(b) a step of filling a part of the box with a thermosetting resin before curing;

(c) the step of forming the tube sheet by curing the filled thermosetting resin; and

(d) A step of providing an annular sealing member between the outer peripheral surface of the tube sheet and the inner peripheral surface of the box after the thermosetting resin is cured.

By applying a release agent as in the step (a) above, the tube sheet (epoxy resin as an example) is well released from the casing (metal as an example) in the curing step of step (c). Assuming that no release agent is used, the tube sheet may not separate from the main body when the resin is cured, and cracks may occur on the tube sheet in some cases.

In the step (b) above, a mold (not shown) may be attached to the end of the cylindrical member 1011, and the injection of the tube sheet resin may be performed in this state. At this time, the mold has an annular convex portion corresponding to the stepped portion 1021s (see FIG. 26 ) of the tube sheet, and the stepped portion 1021s can be formed on the tube sheet by using this convex portion.

In the above step (d), as described above, an annular elastic member such as an O-ring may be embedded in the groove C1, or resin may be injected into the groove C1 and cured to form the sealing member 1060 .

According to the gas separation membrane module 1001 of the present embodiment as described above, even when the sealing between the outer peripheral surface of the tube sheet and the inner peripheral surface of the box cannot be ensured due to the curing shrinkage of the tube sheet 1021, the sealing member 1060 is additionally provided. , Therefore, the sealing between the two members can be sufficiently ensured.

It is advantageous especially in the case of gas separation membrane modules used at high temperatures. That is, in general, a material that is difficult to cure and shrink tends to have elasticity, have a low glass transition temperature, and tend to lack heat resistance. On the other hand, tubesheet materials with excellent heat resistance tend to shrink when cured. If such a heat-resistant material is used and the tube sheet is bonded to the case, elongation stress may be applied due to curing shrinkage of the tube sheet material, and cracks may be generated in the tube sheet. On the other hand, according to this embodiment, the sticking of the tube sheet material is prevented by applying a release agent in the box, and the sealing between the tube sheet and the box is ensured by the ring-shaped sealing member. Therefore, it is possible to provide a gas separation membrane module that prevents cracks from being generated on the tube sheet and also sufficiently ensures sealing performance.

In the above description, one tube sheet 1021 ( FIG. 26 ) among the two tube sheets 1021 , 1022 was mainly described, but the two tube sheets 1021 , 1022 may have the same configuration. Alternatively, the structure shown in Fig. 26 may be provided on only one tube sheet. Furthermore, the structure of the tube sheet, annular sealing member, and box body as in this embodiment is not limited to a borefeed type assembly, but can also be applied to a shell feed type (shell feed type) assembly, It can also be applied to other types of components.

(Content of invention)

The inventions covered by Section G are as follows.

1. A gas separation membrane module, comprising:

A hollow fiber bundle in which many hollow fiber membranes with gas separation performance are bundled together,

A housing having the above-mentioned hollow fiber bundle disposed therein, and

a tube sheet securing at least one end of said hollow fiber bundle;

The gas separation membrane module is configured such that the outer peripheral surface of the tube sheet is not bonded to the inner peripheral surface of the casing,

Wherein, the gas separation membrane module further includes a sealing member that seals between the outer peripheral surface of the tube sheet and the inner peripheral surface of the box.

2. The gas separation membrane module according to the above 1, wherein the tube sheet has a stepped portion that forms an annular groove in cooperation with the inner peripheral surface of the casing.

3. The gas separation membrane module according to the above 1 or 2, wherein the casing has a cylindrical member surrounding the hollow fiber bundle and a cap member provided at an end of the cylindrical member,

A thick portion having a partially reduced inner diameter is formed on the cylindrical member, and the tube plate abuts against the thick portion, thereby preventing the tube plate from moving axially inward of the cylindrical member.

4. The gas separation membrane module according to any one of 1 to 3 above, wherein the sealing member is an annular elastic member fitted into the annular groove.

5. A method for manufacturing a gas separation membrane module, the gas separation membrane module comprising: a hollow fiber bundle formed by bundling a plurality of hollow fiber membranes having gas separation performance, a housing in which the hollow fiber bundle is arranged, and Fixing the tube sheet at least one end of the above-mentioned hollow fiber bundle, wherein the gas separation membrane module comprises the following steps:

A step of applying a mold release agent on at least the part where the tube sheet is in contact with the inner peripheral surface of the above-mentioned box,

A step of filling a part of the above box with a thermosetting resin,

the step of forming the above-mentioned tube sheet by curing the above-mentioned thermosetting resin, and

A step of providing a sealing member between the outer peripheral surface of the tube sheet and the inner peripheral surface of the box after the thermosetting resin is cured.

[Example]

[Example involving Part A]

Next, the invention of Part A will be further described using examples. In addition, the invention of part A is not limited to the following examples.

<Measuring method of glass transition temperature (Tg) of hollow fiber membrane>

According to JIS K7121's extrapolated glass transition onset temperature measurement method, Shimadzu Corporation's DSC50 device is used to measure the glass transition temperature (Tg ) determination.

<Measuring method of shape retention rate of hollow fiber membrane>

In the measurement of the shape retention rate, the length before and after heat treatment of a 200 mm long hollow fiber held in a hot-air thermostat at 175° C. for 2 hours was measured. The ratio of the length after the heat treatment to the original length before the heat treatment was defined as the shape retention rate.

<Measuring method of solution viscosity>

The solution viscosity of the polyimide solution was measured at a temperature of 100° C. using a rotational viscometer (shear rate of the rotor: 1.75 sec ⁻¹ ).

<Manufacturing example 1>

In a detachable flask equipped with a stirrer and a nitrogen inlet pipe, add 4,4'-(hexafluoroisopropylidene)-bis(phthalic anhydride) 200 millimoles together with 1882 g of solvent 4-chlorophenol, 225 mmoles of 3,3',4,4'-biphenyltetracarboxylic dianhydride, 75 mmoles of pyromellitic dianhydride, 250 mmoles of 2,2',5,5'-tetrachlorobenzidine and 3 , 7-diamino-dimethyldibenzothiophene=5,5-dioxide 250 millimoles, carry out the polymerization imidation reaction at a reaction temperature of 190° C. under stirring while feeding nitrogen in the flask for 20 hours, an aromatic polyimide solution having a polyimide concentration of 17% by weight was prepared. The solution viscosity at 100° C. of this aromatic polyimide solution was 1940 poise.

The aromatic polyimide solution prepared above was filtered through a 400-mesh metal mesh, and used as a doping solution, and the hollow fiber spinning nozzle (circular The outer diameter of the circular opening is 1000 μm, the slit width of the circular opening is 200 μm, and the outer diameter of the core opening is 400 μm), and the dopant liquid is sprayed from the circular opening, and nitrogen gas is sprayed from the core opening at the same time to form a hollow filament , after passing it in a nitrogen atmosphere, it was immersed in a coagulation solution to coagulate it, and it was pulled by a pulling roll to obtain a wet hollow fiber membrane. Next, the hollow fiber membrane was dried and further heat-treated at 250° C. for 30 minutes to obtain a hollow fiber membrane 1 .

The obtained hollow fiber membrane 1 had an approximate outer diameter of 410 μm and an inner diameter of 280 μm. The tow elements are formed from the hollow fiber membranes, and then the gas separation membrane modules are formed from the tow elements of the respective hollow fiber membranes.

In Examples 1 and 2, air separation membrane modules 1 using the hollow fiber membranes 1 manufactured above were used, and in Comparative Examples 1 and 2, air separation membrane modules 2 or 2 using the following hollow fiber membranes 2 were used. An air separation membrane module 3 using a hollow fiber membrane 3 .

Table 1 shows properties and the like of each hollow fiber membrane. The glass transition temperature and the shape retention rate were measured by the above-mentioned methods.

【Table 1】

^* 1: Hollow fiber membrane 1 does not exist when the glass transition temperature is 300 degrees or less, so it cannot be measured by the above method.

^* 2: _P'O2 indicates the oxygen transmission rate at 40°C.

Table 2 shows various conditions of each air separation membrane module.

【Table 2】

<Example 1 of Part A>

Air at 175°C was supplied to the air separation membrane module 1 at a pressure of 0.2 MPaG, and the air supply rate was adjusted so that the oxygen concentration in nitrogen-enriched air, which is the non-permeate gas, was 12%, and the operation was continued under these conditions. The flow rate of the produced nitrogen-enriched air was measured for each elapsed time after the start of operation. The measurement results are shown in Fig. 1 . In addition, based on the measurement results, the oxygen permeation rate (P' _O2 ) of the air separation membrane after 0 hour, 140 hours, and 2069 hours from the start of operation, and the ratio of the oxygen permeation rate and the nitrogen permeation rate showing the separation performance were calculated. (P' _O2 /P' _N2 ). The results are shown in Table 3.

At the moment when the operation has started (0 hour), _P'O2 is 35.4×10 ^-5 cm ³ (STP)/cm ² ·sec·cmHg, and the flow rate of nitrogen-enriched air obtained from the air separation membrane module 1 is 0.748Nm ³ /h. After 140 hours from the start of the operation, _P'O2 was 33.4×10 ^-5 cm ³ (STP)/cm ² ·sec·cmHg, which was only 5.6% lower than that at the start of the operation. The _P'O2 after 2069 hours from the start of the operation was 31.4×10 ^-5 cm ³ (STP)/cm ² ·sec·cmHg, which was 11% lower than that at the start of the operation. The flow rate of nitrogen-enriched air obtained from the air separation membrane module 1 after 2069 hours from the start of operation was 0.65 Nm ³ /h, which was only 13% lower than that at the start of operation. From this result, it can be seen that the air separation membrane module 1 maintains the gas separation membrane capability even when it is operated at 175° C. for 2000 hours.

<Comparative Example 1 of Part A>

Using the air separation membrane module 2, the same measurement as in Example 1 was attempted, but the shrinkage of the hollow fiber membrane was severe at 175°C, and nitrogen-enriched air could not be obtained. In the air separation membrane module 2 maintained at 175° C., broken hollows, broken wires, deformation of tube sheets, and the like were observed.

<Comparative Example 2 of Part A>

Except for using the air separation membrane module 3, operation was performed under the same conditions as in Example 1, and the flow rate of nitrogen-enriched air was measured for each elapsed time. The measurement results are shown in Fig. 1 . The _P'O2 at the start of operation was 19.3×10 ^-5 cm ³ (STP)/cm ² ·sec·cmHg, and the flow rate of nitrogen-enriched air obtained from the air separation membrane module was 0.625Nm ³ /h. After 140 hours from the start of operation, the _P'O2 of the separation membrane was 11.3×10 ^-5 cm ³ (STP)/cm ² ·sec·cmHg, which was 41% lower than that at the beginning of operation. The P'O2 obtained from the air separation membrane module The flow rate of nitrogen-enriched air is 0.419Nm ³ /h, which is 35% less than that at the beginning of use.

<Example 2 of Part A>

Measurement was performed in the same manner as in Example 1 except that the air supply rate was adjusted so that the oxygen concentration in the produced nitrogen-enriched air was 5%. The measurement results are shown in FIG. 2 . The flow rate of nitrogen-enriched air at the time of starting operation was 0.18 Nm ³ /h. The flow rate of nitrogen-enriched air 2069 hours after the start of operation was 0.15 Nm ³ /h, which was reduced by 16%. From these results, it can be seen that, similarly to Example 1, the air separation membrane module 1 maintains the gas separation membrane capability even after 2000 hours at 175°C.

[Example involving Part B]

Hereinafter, although the invention of part B is demonstrated using an Example, this invention is not limited to an Example.

<Example 1>

(Manufacture of casting resin composition)

100 parts by weight of polyglycidyl ether of novolac and 10 parts by weight of carboxyl-terminated butadiene-acrylonitrile copolymer (molecular weight: 3100) were mixed, and heated at 150° C. for 3 to 4 hours to prepare a modified epoxy resin. 100 parts by weight of modified epoxy resin prepared by mixing system, 80 parts by weight of methyl-5-norbornene-2,3-dicarboxylic acid anhydride and 0.3 parts by weight of 2-ethyl-4-methylimidazole are stirred Thus, a casting resin composition was prepared.

(Evaluation of Formability of Tube Sheet)

的模具内配置有将12000根聚酰亚胺空心丝膜(长度：100cm、外径：500μm)集束成的丝束。使丝束的前端为下而实质上直立，将通过上述手法制备的铸型树脂组合物慢慢注入到保温为70℃的模具内。铸型树脂组合物的量被控制成厚度为90mm左右。注入后，在70℃下进行12小时一次固化后，加热至142℃并进行4小时后固化，由此进行管板的成形。固化后，从箱体中取出空心丝元件并通过目视进行观察，进而将管板切开为大致两半并对中心部的状态也通过进行目视观察。As shown in Figure 4b in

A bundle of 12,000 polyimide hollow fiber membranes (length: 100 cm, outer diameter: 500 μm) was arranged in the mold. The casting resin composition prepared by the above-mentioned method was slowly poured into a mold kept at 70° C. with the front end of the tow pointing down and substantially upright. The amount of the casting resin composition is controlled so that the thickness is about 90 mm. After pouring, after performing primary curing at 70 degreeC for 12 hours, it heats at 142 degreeC and performs post-curing for 4 hours, and the shaping|molding of a tube sheet is performed. After curing, the hollow fiber element was taken out from the box and observed visually, and the tube sheet was cut into roughly two halves and the state of the central part was also visually observed.

As a result, no cracks were observed in the formed tube sheet.

[Example related to Part E]

The results of simulations of the responses of the gas separation membrane modules with and without the membrane member wound up are shown below. Table 1 shows the responses of the modules, "pattern A (cross flow)" is the case where the membrane member is not wound, and "pattern B (counterflow)" is the case where the membrane member is wound. The temperature was set at t=25° C., and the supply pressure of the mixed gas was set at PF=0.7 MPaG for calculation. It should be noted that, here, the simulation was performed on a separation membrane module obtained by supplying air as a mixed gas and using nitrogen-enriched air as a product. This nitrogen-enriched air is taken out as non-permeated gas that passes through the hollow fiber membrane and is discharged from the downstream side end thereof. The supply pressure and supply flow rate in the table represent the supply pressure and flow rate of the air which is the mixed gas respectively, the product concentration and the product flow rate represent the nitrogen concentration and flow rate of the nitrogen-enriched air which is the product obtained without permeating the gas, respectively, and the recovery rate is expressed in The ratio ((product flow rate/supply flow rate)*100) obtained as non-permeated gas of the product in the mixed gas supplied.

【Table 4】

As shown in Table 4, at the same supply flow rate FF (refer to the main body 1 and 2), the product concentration XR can be increased in the case of the main body 2 wound with the membrane member. On the other hand, at the same product concentration XR (see main bodies 1 and 3), the product flow rate FR and recovery rate can be improved in the case of the main body 3 wound with the membrane member. That is, from these results, it can be seen that the wound membrane member is effective in increasing the efficiency of gas separation.

Claims (5)

1. A method for producing nitrogen-enriched air from air using an air separation membrane module,

air above 150 ℃ is supplied to the air separation membrane module.

2. The method of claim 1,

the air separation membrane module has an oxygen transmission rate (P ') at 175 ℃ at the start of use'_O2) Is 20X 10^-5cm³(STP)/cm²Sec cmHg or moreAnd a ratio (P ') of oxygen transmission rate to nitrogen transmission rate at 175 ℃'_O2/P’_N2) Is 1.8 or more, and

p 'at 175 ℃ for 140 hours'_O2And P'_O2/P’_N2P 'before the use is kept'_O2And P'_O2/P’_N2Each of which is 90% or more.

3. The method of claim 1,

the air separation membrane within the air separation membrane module is formed from a material that does not exhibit a glass transition temperature below 225 ℃.

4. The method of claim 1,

the air separation membrane showed a shape retention rate of 95% or more when left at 175 ℃ for 2 hours.

5. A method for explosion protection of an aircraft, characterized in that,

nitrogen-enriched air produced by the method of claim 1 and supplied to an aircraft fuel tank.

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