JP2002143655A - Ceramic filter and producing method of ceramic filter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a ceramic filter and a producing method of a ceramic filter which enable simply producing filters excellent in filtration performance. SOLUTION: First of all, porous tubes 2 are produced by a dry and wet spinning method, the porous tubes 2 are arranged within a case which becomes the external shape of a product by required pieces, ceramic material is filled into gaps among outer walls of the arranged porous tubes 2, the porous tubes 2 are bonded one another, and thereby, the ceramic material becomes a supporting layer 3 which supports the porous tubes 2 and, at the same time, becomes a barrier.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ceramic filter for removing fine particles from a gas or a liquid and a method for manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, as a ceramic filter of this type, for example, a monolithic ceramic filter having a honeycomb shape is known.

[0003] A ceramic material having a large number of pores can function as a filter. However, when the pore size of these pores is set to a diameter necessary for removing fine particles and a filter is formed, the permeation of the filter becomes poor. Performance is inferior.

[0004] For this reason, the pores of the main part of the ceramic material (hereinafter referred to as a support layer) are set to be larger than the diameter required for removal, while a passage (hole) serving as a flow path is formed in the support layer. By forming a filtration membrane (thin film) on the surface of this passage and setting the diameter of a plurality of pores provided in the filtration membrane to a diameter necessary for removing fine particles, pressure loss can be prevented. This suppresses a decrease in transmission performance.

[0005] In the case of a monolithic ceramic filter, a plurality of through-holes are usually formed in a honeycomb shape in which a plurality of through-holes extending in the axial direction are formed in a cylindrical support layer. It has a configuration in which a filtration membrane is formed on the surface.

[0006] With such a configuration, only a specific component is permeated or removed by the filtration membrane formed on the surface of the passage to perform separation.

Next, a conventional example of a method for manufacturing the above-described monolithic ceramic filter will be described.

In the case of the monolithic ceramic filter, first, a cylindrical support layer having a plurality of through holes extending in the axial direction is formed, and then a filtration membrane is formed on the surface of the through hole.

Here, regarding the honeycomb-shaped support layer,
A specific example of the manufacturing process will be described. FIG. 4 (A)
5 is a flowchart showing a manufacturing process of a monolithic ceramic filter according to the related art.

First, ceramic powder having an appropriate particle size is
After adding an inorganic bonding material (binding material), an organic binder, a solvent (water), and the like, kneading and extruding the mixture to form a clay.
After extruding the kneaded material with an extruder having a die having a predetermined shape, the kneaded material is dried and further fired to obtain a support layer having a honeycomb structure.

The average pore diameter of the through-hole provided in the supporting layer of the honeycomb structure obtained as described above is 0.0
A monolithic ceramic filter can be obtained by forming a filtration membrane made of a porous ceramic of 02 μm to 5 μm.

Here, a specific example of the manufacturing process of the filtration membrane will be described.

[0013] A solvent such as water, an organic binder, a peptizer, a pH adjuster and the like are added to a ceramic powder or a colloid solution having an appropriate particle size and mixed to obtain a slip. This slip can be coated on the inner peripheral surface of the above-mentioned through-hole, dried and fired to obtain a filtration membrane.

[0014]

However, in the case of the above-described prior art, the following problems have occurred.

As described above, in the case of the monolithic ceramic filter, the separation and removal of the target fine particles are performed by the filtration membrane formed on the inner peripheral surface of the through hole of the support layer. The performance of the membrane is important because it determines its performance as a filter.

Here, in the case of the above-mentioned conventional manufacturing method,
In order to form a filtration membrane having a uniform structure, it is desired that the state of the inner peripheral surface of the through hole be uniform.

In order to achieve such conditions, advanced manufacturing techniques have been required.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and an object of the present invention is to provide a ceramic filter capable of easily manufacturing a filter having excellent filtration performance and a method of manufacturing the ceramic filter. It is to provide a method.

[0019]

In order to achieve the above-mentioned object, a ceramic filter according to the present invention comprises a plurality of tubes having a plurality of pores on a wall surface and an outer wall of the plurality of tubes. A porous ceramic material filled in the gaps,
It is characterized by having.

Therefore, since the porous ceramic material has a structure filled in the gaps between the outer walls of many tubes, the separation performance (a plurality of pores on the wall surfaces of the tubes function as a separation membrane). This performance as a separation function) is independent of the filled ceramic material.

The ceramic material may include at least one of alumina, silica, zirconia, titania, mullite, spinel, cordierite, carbon, silicon carbide, and silicon nitride.

It is also preferable that the ceramic material is an inorganic adhesive or cement.

The pore diameter of the pores of the tube is 0.002 μm or more.
The thickness is preferably 10 μm.

[0024] The pore diameter of the pores of the ceramic material is 0.1.
The thickness is preferably 2 μm to 100 μm.

The tube is preferably obtained by a dry-wet spinning method.

In the method for manufacturing a ceramic filter according to the present invention, a first step of manufacturing a tube having a plurality of pores on a wall surface and a plurality of tubes obtained in the first step are placed in a case. It is characterized by comprising a second step of arranging, and a third step of filling a gap between outer walls of a plurality of tubes arranged in the case with a ceramic material and bonding each tube.

Therefore, after the tube is manufactured in the first step, and after passing through the second step, the ceramic material is filled in the third step, the separation performance (the performance obtained by the pores provided on the wall surface of the pipe) Is not affected by the ceramic material to be filled in the third step.

In the first step, the tube is preferably manufactured by a dry-wet spinning method.

[0029]

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, the dimensions of the components described in this embodiment,
The materials, shapes, relative arrangements, and the like are not intended to limit the scope of the present invention only to them unless otherwise specified.

With reference to FIGS. 1 to 4, a ceramic filter and a method of manufacturing the ceramic filter according to an embodiment of the present invention will be described.

First, the configuration and the like of a ceramic filter according to an embodiment of the present invention will be described with reference to FIG. FIG. 1 is a schematic perspective view of a ceramic filter according to an embodiment of the present invention.

As shown in FIG. 1, a ceramic filter 1 according to an embodiment of the present invention generally includes a plurality of porous tubes 2 functioning as a filtration membrane for separating fine particles in a gas or a liquid, and a porous filter 2. And a support layer 3 serving as a partition wall while supporting the tube 2. Also, near both ends,
A glass coat part 4 whose surface is coated with glass is provided.

The porous tube 2 is provided with a plurality of fine pores having a uniform pore diameter on the wall surface.
It is preferable to use one having a thickness of 10 μm. Such a perforated tube 2 is disclosed in, for example, Japanese Patent Publication No. 5-6634 by the present applicant.
By using the manufacturing method disclosed in Japanese Unexamined Patent Application Publication No. 3-3, it is possible to manufacture easily and inexpensively.

According to this production method, the pore diameter and the porosity can be arbitrarily produced according to the particle diameter of the raw material to be used and the firing conditions, and the outer diameter and the wall thickness of the porous tube 2 are determined by the nozzle to be used. The production can be arbitrarily performed depending on spinning conditions.

Here, the filtration characteristics of the filter depend on physical factors such as the pore diameter and porosity, and do not depend on the material.
Metals such as Inconel, Hastelloy, and any ceramic such as alumina, silica, zirconia, titania, mullite, spinel, cordierite, carbon, silicon carbide, silicon nitride, and mixtures of some of these can be used. it can.

The support layer 3 is made of a ceramic material that fills the gap between the outer walls of the perforated tube 2, and this ceramic material has a bad influence on the structure of the perforated tube 2 when the support layer 3 is manufactured. A material that is sintered at a temperature lower than the firing temperature at which the porous tube 2 is fired is selected so as not to cause the sintering.

The support layer 3 has uniform pores,
Although a uniform structure is not required, the smaller the filtration resistance (the resistance when the fluid flows), the better. Therefore, the larger the pore diameter and the porosity, the better. For example, the pore diameter is 0.2 μm to 1 μm.
A ceramic material that satisfies 00 μm and porosity of 10 to 60% is preferable.

Examples of such ceramic materials include arbitrary materials such as alumina, silica, zirconia, titania, mullite, spinel, cordierite, carbon, silicon carbide, silicon nitride, and mixtures of some of these. Ceramic can be used.

Further, an inorganic adhesive or cement capable of forming a porous body can be used.

Next, an example of use of the ceramic filter 1 according to the embodiment of the present invention will be described with reference to FIG. 2 and FIG. Here, a case where the present invention is applied as a separation device for separating and removing a specific component will be described.

FIG. 2 is a schematic sectional view of a separation device incorporating a ceramic filter according to an embodiment of the present invention.
FIG. 3 is an explanatory diagram illustrating a separating operation in the separating device shown in FIG.

As shown in FIG. 2, when the ceramic filter 1 is accommodated in the case 10, the separating device 100 has a first edge in which one end of the ceramic filter 1 is accommodated by the partitions 11 and 12 provided in the case 10. The chamber S1 is separated into a second chamber S2 in which the side surface of the ceramic filter 1 is accommodated, and a third chamber S3 in which the other end of the ceramic filter 1 is accommodated.

Here, since the partition walls 11 and 12 are in liquid-tight contact with the glass coat portion 4 of the ceramic filter 1, the first chamber S1 and the second chamber S2 are provided outside the ceramic filter 1 (on the outer peripheral surface side). And the fluid does not flow between the second chamber S2 and the third chamber S3.

With the above configuration, as shown in FIG.
First, a fluid containing a specific component flows into the second chamber S2 from the inflow port 13 (arrow P0), flows along the outer peripheral surface of the ceramic filter 1 (arrow P1), and flows out of the separation apparatus 100 from the outflow port 14. (Arrow P2). Here, the specific component is separated in the process of flowing in the direction of arrow P1.

On the other hand, a fluid for discharging the separated specific component flows into the third chamber S3 from the inflow port 15 (arrow Q0), and passes through the inside 21 of the perforated pipe 2 to form the first chamber S1. Through the outlet 16, it flows out of the separation device 100 (arrow Q <b> 1).

The operation of separating a specific component at this time will be described with reference to FIG.

As described above, in the process in which the fluid containing the specific component flows along the outer peripheral surface of the ceramic filter 1 (arrow P1), this fluid enters the inside of the support layer 3 having a small filtration resistance (arrow). R1).

Then, only the specific component contained in the fluid penetrates the wall surface of the perforated tube 2 and enters the inside 21 of the perforated tube 2 according to the concentration gradient of the fluid flowing through the inside of the tube 21 (arrow R2). From the outlet 16 through the first chamber S1, the separation device 10
It flows out of 0.

As described above, the wall surface of the porous tube 2 functions as a filtration membrane.

Next, a method of manufacturing the ceramic filter according to the embodiment of the present invention will be described. FIG. 4 (B)
5 is a flowchart showing a manufacturing process of the ceramic filter according to the embodiment of the present invention.

In this embodiment, first, the porous tube 2
To manufacture. As described above, the manufacturing method disclosed in Japanese Patent Publication No. 5-66343 can be used for manufacturing the porous tube 2.

This manufacturing method is called a dry-wet spinning method. In a general dry-wet spinning method, a raw material is dissolved in a solvent and spun by a nozzle, and a spinning solution is extruded into the air to form an air gap ( In this method, a void is provided to control the orientation of the molecular chains, and the solvent is removed in a water bath to regenerate the fiber.

Then, the perforated pipes 2 are arranged in a required number in a case having the outer shape of the product, and the above-described ceramic material (filling slurry) is filled in the gaps between the outer walls of the arranged perforated pipes 2. After filling, the porous tube 2 is bonded.

The ceramic material serves as the support layer 3, supports the porous tube 2, and serves as a partition.

[0055]

Next, more specific examples based on the above-described embodiment will be described in the order of manufacturing steps.

First, polysulfone (product P-1 manufactured by UCC)
700) 7 parts by weight, fine alumina powder (particle size 0.3 μm)
78 parts by weight and N, N-dimethylformaldehyde 4
A spinning stock solution consisting of 5 parts by weight of a mixture was prepared with an inner diameter of 2.0 m.
The composite hollow fiber having an inner diameter of about 2.8 mm and an outer diameter of about 3.5 mm is obtained by spinning using a double-ring type nozzle having an outer diameter of 3.0 mm and a dry-wet spinning method under the following spinning conditions. Was.

The spinning conditions are as follows: the core liquid flow rate is 5 ml / min, the stock solution flow rate is 20 ml / min, the distance between the nozzle outlet and the gelling bath is 5 cm, the gelling bath temperature is 10 ° C., and the winding speed is 16.8.
m / min.

The composite hollow fiber obtained in this manner was
After calcining at 00 ° C. for 5 hours, the resultant was calcined at 1400 ° C. for 2 hours to obtain an alumina porous tube having an inner diameter of about 2.4 mm and an outer diameter of about 3.0 mm. The obtained porous tube had a symmetric structure in cross section, a porosity of 40% or more, and a sharp pore size distribution with an average pore size of 0.2 μm.

Further, alumina 10 having an average particle diameter of 40 μm was used.
A predetermined amount of water was added to 0 parts by weight, 8 parts by weight of glass powder, and 5 parts by weight of methylcellulose and mixed well to obtain a slurry for filling.

Here, both ends of a vertically splittable stainless steel tube having an inner diameter of 30 mm and a length of 300 mm are clamped and fixed.
The bottom lid was attached and used as a case having the outer shape of the monolith.

In this case, a length of about 300 m
Nineteen perforated tubes cut to m were arranged evenly.

After disposing the perforated tubes, the above-mentioned filling slurry was poured into the case, filled in the gaps between the outer walls of each perforated tube, and dried.

After drying, the case was removed and 12
It was baked at 50 ° C.

The monolithic ceramic filter was obtained by coating both ends of the ceramic filter thus obtained and the outer wall surface of about 10 mm from both ends with glass.

At this time, the average pore diameter of the support layer was about 10 μm.
On the inner peripheral surface of the perforated tube serving as a passage for the supplied fluid to be filtered, the state in which the fine pores were uniformly distributed was maintained, and the average pore diameter was 0.2 μm.

[0066]

As described above, the present invention has a structure in which a porous ceramic material is filled in the gaps between the outer walls of a large number of tubes, so that the separation performance becomes independent of the ceramic material, and the separation performance is simplified. It is possible to produce a filter having excellent filtration performance.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view of a ceramic filter according to an embodiment of the present invention.

FIG. 2 is a schematic sectional view of a separation device incorporating a ceramic filter according to an embodiment of the present invention.

FIG. 3 is an explanatory diagram illustrating a separating operation in the separating device.

FIG. 4 is a flowchart showing a manufacturing process ((A) is a conventional process, and (B) is an embodiment of the present invention).

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ceramic filter 2 Perforated pipe 21 Inside 3 Support layer 4 Glass coat part 10 Case 11, 12 Partition wall 13 Inlet 14 Outlet 15 Inlet 16 Outflow 100 Separation apparatus S1 1st chamber S2 2nd chamber S3 3rd chamber

Continued on front page F-term (reference) 4D006 GA07 GA44 HA01 JA03C JA04C JA07C JA08C JB04 JB09 MA01 MA09 MA10 MA22 MC03X MC05 NA04 NA46 NA51 NA54 NA62 4D019 AA01 AA03 BA05 BB06 CA03 CB06

Claims (8)

[Claims] 1. A ceramic comprising: a plurality of tubes having a plurality of pores on a wall surface; and a porous ceramic material filled in gaps between outer walls of the plurality of tubes. filter. 2. The ceramic material according to claim 1, wherein said ceramic material contains at least one of alumina, silica, zirconia, titania, mullite, spinel, cordierite, carbon, silicon carbide and silicon nitride. The ceramic filter according to 1. 3. The ceramic filter according to claim 1, wherein the ceramic material is an inorganic adhesive or cement. 4. A tube having a pore diameter of 0.002 μm or less.
4. The structure according to claim 1, wherein the thickness is 10 [mu] m.
The ceramic filter according to 1. 5. The ceramic material according to claim 1, wherein said fine pores have a pore diameter of 0.1.
2 .mu.m to 100 .mu.m.
5. The ceramic filter according to any one of 4. 6. The ceramic filter according to claim 1, wherein the tube is obtained by a dry-wet spinning method. 7. A first step of manufacturing a tube having a plurality of pores on a wall surface, a second step of arranging a plurality of tubes obtained in the first step in a case, and arranging a plurality of tubes in the case. A third step of filling the gap between the outer walls of the filled tubes with a ceramic material and bonding each tube;
A method for manufacturing a ceramic filter, comprising: 8. The method according to claim 7, wherein in the first step, the tube is manufactured by a dry-wet spinning method.