JP2015089536A - Separation membrane element and separation membrane module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a separation membrane element where backflow, back pressure and contamination from a permeation side can be prevented even when a check valve disposed at downstream from a separation membrane module is damaged and removal can be achieved to be easier than ever before without requiring manpower and time when inspecting.SOLUTION: In a separation membrane element 301, a membrane unit including a separation membrane to separate the component of a medium to be treated is wound to be spiral around a center tube 304 having a plurality of pores, the outer periphery of the wound membrane unit has a structure that a wound body is formed by being covered with an outer package, and the center tube disposed with a check valve 305 at downstream side from a pore at a lowermost downstream part in a plurality of the pores existing on the side surface of the center tube is used.

Description

  The present invention relates to a spiral separation membrane element that separates components present in a fluid and a separation membrane module using the same.

  In recent years, various fluid separation fields using membrane permeates such as ultrapure water applications and general irrigation applications in the semiconductor field have rapidly developed. In particular, the demand for separation membrane elements is increasing in order to obtain water used for ultrapure water use and general brine use from river water and groundwater.

  Separation membrane element uses reverse osmosis and filtration mechanism to remove foreign substances and salt contained in solution from seawater, river water, groundwater, etc., and lower than the original solution of fresh water, pure water and ultrapure water It is used to obtain a salt concentration solution.

  Conventionally, among these types of separation membrane elements, a membrane unit including a separation membrane for separating components of a medium to be treated is spirally wound around a central tube having a plurality of holes, and the wound membrane In a fluid treatment system using a spiral type separation membrane element having a structure in which the outer periphery of a unit is covered with an exterior body to form a wound body, the spiral from the permeation side when the system is down as in Patent Document 1 In order to prevent backflow and back pressure to the separation membrane element of the mold, it is common to provide a check valve in the pipe downstream of the separation membrane module. The reason for preventing backflow is that the separation membrane used in the spiral type separation membrane element having the above structure is composed of a functional layer, a support layer, and a base material, and the peel strength between the support layer and the base material is too high. This is because the separation membrane is damaged when subjected to backflow or back pressure from the permeate side. Furthermore, by providing a check valve, there is also an effect of preventing contamination from the permeation side, and it is also necessary to prevent deterioration of the quality of the separation membrane due to contamination of foreign matters. Here, contamination means mixing of foreign matters and impurities remaining in a pipe of a water treatment device or the like. According to the knowledge of the present inventors, at this time, if the check valve provided downstream of the separation membrane module has failed, the backflow and back pressure to the separation membrane element cannot be prevented, and the separation valve There is a possibility that the separation membrane element loaded in the membrane module may be totally damaged.

  Further, as an example in which a check valve is provided in the central tube of the spiral type separation membrane element, there is a separation membrane element as disclosed in Patent Document 2, but in this separation membrane element, the check valve is located in the center of the central tube. This was not provided for preventing backflow and back pressure from the permeate side, and further preventing contamination on the downstream side.

JP 2011-036752 A Japanese Utility Model Publication No. 61-175209

  In the system using the conventional spiral separation membrane element described above, when the check valve provided downstream of the separation membrane module is damaged, or when the system is inadvertently down such as a power failure, the separation membrane module has a backflow or back pressure. The spiral-type separation membrane element in FIG. 1 may lead to total damage, and there is still concern about contamination of the separation membrane. Furthermore, if the check valve is not provided due to design deficiencies or the like, it is necessary to reconstruct the pipe connection.

  Therefore, an object of the present invention is to prevent backflow, back pressure and contamination from the permeate side even when a check valve provided downstream of the separation membrane module is damaged, and is loaded into the separation membrane module. Separation membrane element that can minimize breakage of separation membrane element, and prevents reverse flow, back pressure and contamination from the permeate side without providing a check valve downstream from the separation membrane module It is to provide a separation membrane element that can be used.

  Another object of the present invention is to provide a separation membrane module that enables the above processing functions.

  The present invention has been made to solve the above problems, and in the separation membrane element of the present invention, a membrane unit including a separation membrane that separates components of a medium to be processed is spiraled around a central tube having a plurality of holes. The outer periphery of the wound membrane unit is covered with an exterior body to form a wound body, and the downstream end of a plurality of holes on the side surface of the central tube as the central tube This is a spiral separation membrane element using a central tube provided with a check valve on the downstream side of the hole of the part.

  The separation membrane module of the present invention is a separation membrane module formed by loading one or more of the above separation membrane elements in a pressure vessel.

  The separation membrane module of the present invention is a separation membrane module in which one or more separation membrane elements are loaded in series in the flow direction in the pressure vessel, and the separation membrane element is loaded in the most downstream in the pressure vessel. This is a separation membrane module.

  The fluid treatment method of the present invention is a fluid treatment method in which the separation fluid is treated on the surface of the separation membrane by filtration, forward osmosis or reverse osmosis using the separation membrane element.

  According to the spiral type separation membrane element of the present invention, since the check valve is provided on the downstream side of the most downstream portion of the plurality of holes in the central tube, the conventional spiral type separation membrane element is loaded. Even when a check valve provided downstream such as a separation membrane module is damaged, backflow, back pressure, and contamination from the permeate side can be prevented, preventing deterioration of quality due to damage to the separation membrane and contamination with foreign matter. it can.

FIG. 1 is a partially exploded perspective view showing an example of a spiral type separation membrane element to which the present invention is applied. FIG. 2 is a cross-sectional view for illustrating the spiral separation membrane element in the present invention. FIG. 3 is a cross-sectional view for illustrating and explaining another spiral separation membrane element in the present invention. FIG. 4 is a cross-sectional view for exemplifying a mode in which two or more separation membrane elements are used simultaneously in another spiral separation membrane element in the present invention. FIG. 5 is a cross-sectional view for illustrating the mode of connection by the connector when the separation membrane elements are connected to each other. FIG. 6 is a cross-sectional view for illustrating an example in which separation membrane elements are connected to each other using an inner type connector. FIG. 7 is a cross-sectional view for illustrating the check valve mounting method.

  In the separation membrane element of the present invention, a membrane unit including a separation membrane that separates components of a medium to be processed is spirally wound around a central tube having a plurality of holes, and the outer periphery of the wound membrane unit Is a structure in which a wound body is formed by covering with an exterior body, and as the central tube, a check valve is provided on the downstream side of the most downstream portion of the plurality of holes on the side surface of the central tube. A spiral separation membrane element using a central tube.

  In the present invention, the central tube is a tube in which the processing medium is collected, and a plurality of holes are formed on the side surface of the central tube so that the processing medium can enter the central tube. Is provided. A plurality of holes are opened at approximately equal intervals in the length direction, and the number varies depending on the diameter and length of the separation membrane element, but generally four or more holes are provided in the length direction. . The material of the center tube is vinyl chloride or the like. The central pipe is sometimes used in the terms of a water collecting pipe and a central pipe.

  In the present invention, the separation membrane is a member that physically separates the contents in the medium to be treated, such as reverse osmosis, filtration, or charge removal. In the separation membrane element, a spiral is formed around the central tube. It is wrapped in a shape. The material of the separation membrane is mainly a polymer such as cellulose or aromatic polyamide. Separation membranes are classified into types such as ultrafiltration membranes, microfiltration membranes, degassing membranes, and reverse osmosis membranes, depending on the pore size on the surface of the separation membrane and the separation method.

  In the present invention, the medium to be treated is a gas or liquid in which a solute such as a compound is treated, which is treated by the separation membrane, and seawater, tap water, gas, NaCl solution, and various other aqueous solutions are preferably used. . Further, the processing medium refers to a medium in which the concentration of the contained substance is reduced with respect to the processing medium by processing the processing medium with a separation membrane. On the other hand, in the present invention, the medium discharged from the separation membrane element when the concentration of the contained substance is higher than the medium to be treated may be described as the concentration medium.

  Further, in the present invention, the outer package is attached to protect the separation membrane from impact, pressure, dirt, etc. from the outside after spirally winding the separation membrane around the central tube, such as a filament. Fiber-like materials and tape-like seals are used. As this exterior body, one having durability against the operation pressure applied during operation of the water treatment apparatus is selected and used.

  In the present invention, the check valve is a member that allows gas or liquid to pass through only in one direction, and the flow direction of gas or liquid can be arbitrarily changed depending on the installation direction. In addition to the ball type described later, there are other types such as poppet type, swing type, wafer type, lift type and foot type. In addition, since the size and style of the check valve that can be applied differ depending on the applied pressure, it is necessary to select one that meets each specification.

  Next, the separation membrane element and the separation membrane module of the present invention will be described with reference to the drawings.

  FIG. 1 is a partially exploded perspective view showing an example of a spiral type separation membrane element to which the present invention is applied.

  In FIG. 1, a spiral separation membrane element 101 is formed by winding a membrane unit including a separation membrane 102 that separates components of a medium to be processed around a central tube 105 having a plurality of holes. This is a separation membrane element having a structure in which a wound body is formed by covering the outer periphery of the rotated membrane unit with an exterior body (not shown).

  In FIG. 1, the separation membrane 102 has an envelope shape in which three sides other than the central tube 105 side are sealed with a sealing means such as an adhesive, and one open end is bonded to the central tube 105. Between the separation membranes 102, a to-be-treated medium permeation flow path material 103 through which the to-be-treated medium passes is sandwiched. Further, in the separation membrane 102, a processing medium permeation channel material 104 through which the processing medium passes is sandwiched. The medium to be treated, which is pressurized from the outside from the upstream part of the spiral separation membrane element 101, moves between the separation membranes 102 through the medium to be treated permeate flow path material 103. When the medium to be processed is moved, the processing medium that has been processed by filtration, forward osmosis, or reverse osmosis on the surface of the separation membrane 102 passes through the treatment medium permeation flow path member 104 provided in the separation membrane 102 and is collected in the central tube 105. . The processing medium collected in the central tube 105 is collected downstream or upstream of the central tube 105. At this time, the concentrated medium to be processed (concentrated medium) is sent downstream of the spiral separation membrane element 101. At this time, in order to collect the processing medium from an arbitrary direction, it is necessary to install a stopper or a cap on the non-transparent side central tube 105 to prevent permeation from the non-transparent side.

  Next, an example in which the spiral separation membrane element of the present invention is applied will be described.

  FIG. 2 is a cross-sectional view for illustrating the spiral type separation membrane element in the present invention, and FIG. 3 is a cross-sectional view for similarly explaining another spiral type separation membrane element in the present invention. It is. 2 and 3 show the appearance of the separation membrane element according to the present invention and the movement of the check valve during use.

  In FIG. 2, the medium to be treated, which is pressurized from the outside from the upstream portion of the separation membrane element 201, moves between the separation membranes through the medium to be treated permeate flow path material between the separation membranes. When the medium to be processed is moved, the processing medium processed by filtration, forward osmosis or reverse osmosis on the surface of the separation membrane passes through the processing medium permeation flow path material provided in the separation membrane and is collected in the central tube 202. The processing medium collected in the central tube 202 flows downstream of the central tube 202. 2A is a cross-sectional view of the downstream portion of the central tube 202, that is, the position where the check valve 203 is attached. At this time, since the check valve 203 has a mechanism in which the valve opens toward the downstream, the check valve 203 receives the pressure of the processing medium and opens the valve. The processing medium that has passed through the check valve 203 is collected in the downstream portion of the central tube 202. When the fluid processing system is down, the check valve 203 is closed by the backflow pressure flowing from the pipe downstream of the separation membrane element 201 toward the separation membrane element 201 to prevent entry into the central tube 202. be able to.

  It is accommodated in the pressure vessel 302 so as not to enter. In the embodiment of FIG. 3, one or more separation membrane elements 301 loaded in a pressure vessel 302 are handled as a separation membrane module. At this time, a brine seal 303 that suppresses intrusion is disposed on the separation membrane element 301 so that the medium to be treated does not flow downstream of the separation membrane element 301 through a gap between the separation membrane element 301 and the pressure vessel 302. Installed upstream.

  The processing medium is collected in the central tube 304 in the same manner as the fluid processing mode by the spiral separation membrane element of FIG. Thereafter, the processing medium is provided downstream.

  Next, referring to FIG. 3, the movement of the check valve 305 during fluid processing will be described. 3B is a cross-sectional view of the downstream portion of the central tube 304 in the separation membrane element 301 loaded in the pressure vessel 302, that is, the position where the check valve 305 is attached. When the processing medium passes through the check valve 305, the check valve 305 opens the valve by the pressure of the processing medium. Since the pressure in the central pipe (processing medium pressure) is higher than the pressure in the pipe (back pressure), the valve opens without any problem. When the system is down, the check valve 305 is closed by the pressure due to the backflow from the piping, and the backflow, back pressure and contamination are prevented.

  In the above embodiment example, only the processing method in the direction shown in FIG. 3 was used, but by changing the orientation of the spiral separation membrane element 301, it is possible to provide a connector such as a cap on the upstream side. It is possible to prevent contamination from upstream.

  Further, in the above embodiment, the single processing method using one spiral type separation membrane element is used. However, when two or more are used at the same time in order to increase the amount and recovery rate of the processing medium, the separation membrane is used. By loading the spiral-type separation membrane element of the present invention in the most downstream part in the module, backflow, back pressure and contamination can be prevented as described above.

  FIG. 4 is a cross-sectional view for exemplifying a mode in which the separation membrane elements are connected in another spiral type separation membrane element of the present invention.

  In FIG. 4, a plurality of separation membrane elements 401 are accommodated in the pressure vessel 402. A brine seal 404 is provided upstream of the separation membrane element 401 in the same manner as in the embodiment of FIG.

  In FIG. 4, I indicates the upstream when the single separation membrane element 401 is used, and II indicates the downstream when the single separation membrane element 401 is used.

  The processing medium to which pressure is applied from the outside enters the pressure vessel 402 and moves from the upstream part of the separation membrane element 401 at the most upstream part through the processing medium permeation channel material and downstream in the separation film. To do. When the medium to be treated is moved, the treatment medium treated by filtration, forward osmosis or reverse osmosis on the surface of the separation membrane passes through the treatment medium permeation flow path material provided in the separation membrane and is collected in the central tube 403. The concentrated medium is discharged downstream of the separation membrane element 401, becomes a medium to be processed of the separation membrane element 401 on the one downstream side, and further moves downstream while being repeatedly processed. The concentrated medium processed in the most downstream separation membrane element 401 is discharged out of the pressure vessel 402. The processing medium collected in the central tube 403 flows downstream of the central tube 403 and enters the central tube 403 of the separation membrane element 401 on the downstream side. Similarly, the processing medium is collected in the central tube 403 of the separation membrane element 401 on the downstream side, and is sent to the downstream side. Eventually, the processing medium processed in all the separation membrane elements 401 in the pressure vessel 402 is collected and sent to the pressure vessel 402 downstream. 4B is a cross-sectional view of the downstream portion of the central tube 403 in the separation membrane element 401 loaded in the most downstream portion in the pressure vessel 402, that is, the position where the check valve 405 is attached. . At this time, since the check valve 405 has a mechanism in which the valve opens toward the downstream, the valve is opened by receiving the pressure of the processing medium. When the fluid processing system is down, the check valve 405 is closed by the backflow pressure flowing toward the separation membrane element 401 from the pipe downstream of the most downstream separation membrane element 401 and into the central tube 403. Can prevent intrusion.

  At this time, there is a problem even if a conventional separation membrane element penetrating the central tube is used from the most downstream portion to the separation membrane element 401 upstream of the second one instead of the spiral separation membrane element of the present invention. Since it is not necessary to provide a check valve 405 in the conventional separation membrane element, the cost can be reduced by that amount, and the pressure required for generating the processing medium is minimized. be able to.

  Further, the separation membrane element 401 of the present invention can also be used for the spiral type separation membrane element 401 other than the most downstream portion. In this case, since two or more check valves 405 prevent backflow, back pressure and contamination to the spiral separation membrane element 401, if any one of the check valves breaks down But it will be a safer design. Furthermore, the check valve is damaged when the back pressure exceeding the pressure resistance of the check valve 405 is exceeded, but the pressure applied to the check valve decreases as it goes upstream due to pressure loss. Damage to the spiral separation membrane element 401 can be minimized. 4A is a cross-sectional view of the upstream portion of the central tube 403 in the separation membrane element 401 loaded in the most upstream portion in the pressure vessel 402, that is, the position where the check valve 406 is attached. . In this manner, the upstream and downstream orientations of the spiral-type separation membrane element 401 itself at the most upstream portion are arranged in different directions, that is, loaded in the direction of flow from II to I, so that the separation membrane element is controlled by the pressure of the medium to be treated. Since the check valve 406 located on the upstream side of the 401 is closed, the medium to be processed can be prevented from being mixed into the central tube 403 without attaching a cap or the like to the upstream portion of the central tube. It is possible to suppress contamination on the side. However, when a high pressure such as 5.5 MPa is applied to the medium to be treated, such as seawater desalination, it is preferable to provide a connector such as a cap in the upstream portion of the water collection pipe. Therefore, it is desirable to apply this method of use to brine desalination and ultrapure water applications.

  FIG. 5 is a cross-sectional view for illustrating the mode of connection by the connector when the separation membrane elements are connected to each other.

  FIG. 5 shows a simple connection method using an outer type and an inner type connector. As shown in FIG. 5A, the central tube 502 protrudes outside the end of the separation membrane 501 found in the outer type and some inner types, that is, the central tube 502 is longer than the length of the separation membrane 501. When the length is longer, the center tubes 502 are connected to each other by the outer type or inner type connector 503, and the center tube 502 is exposed to the processing medium. Since it is necessary to endure the operating pressure with only the central tube 502, it cannot withstand a high pressure of about 5 MPa that is required for seawater desalination. Therefore, it is preferable to select and use a condition of 1.5 MPa or less as in the brine desalination treatment. Among the inner-type connections as shown in FIG. 5B, the central tube 502 does not protrude from the end of the separation membrane 501, that is, the length of the central tube 502 is shorter than the length of the separation membrane 501. Or, in the same case, when connecting, not only the central tube 502 connected by the inner-type connection connector 504 but also the shape supported by the ends of the separation membrane element, it is 5 MPa or more like seawater desalination treatment. Can withstand high pressures of Here, the inner type connector is a connector for connection that matches the inner diameter of the center tube, and the outer type that matches the outer shape of the center tube.

  FIG. 6 is a cross-sectional view for illustrating another embodiment when the separation membrane elements are connected by an inner type connector.

  (A) in FIG. 6 shows an aspect when connected by a long inner type connector. When the inner type connector 601 is used when connecting, if a central tube with a groove engraved in a large area of the central tube 602 is used as shown in FIG. A connector can be attached. Further, since it is possible to cope with a slightly short connector as shown in FIG. 6B, it is possible to effectively connect.

  In the above-described embodiment shown in FIG. 3, the check valve 305 is installed in the central tube 304. However, the central tube 304 of the spiral separation membrane element using the existing through-type central tube is used. A check valve 305 that matches the inner diameter can also be used. In addition, a ball type as shown in FIG. 3 is generally used for the check valve 305, but other check valves such as a poppet type, a swing type, a wafer type, a lift type and a foot type are used. However, it is necessary to select arbitrarily according to the operating pressure. In addition, the check valve may be made of any material such as plastic, resin, metal, etc., but it is necessary to select it arbitrarily depending on the substance contained in the processing medium. For example, in a separation membrane element for use in seawater desalination, NaCl is also contained in the processing medium, and therefore a SUS product is preferable when using a metal. Further, the check valve has a member that plugs (for example, a ball) and a member that receives the plug (for example, metal). These materials can be selected by selecting a material that has elasticity for either member. It is possible to close more densely than in the case of metal.

  FIG. 7 is a cross-sectional view for illustrating the check valve mounting method.

  In FIG. 7, the check valve may be attached with an adhesive 701 in the central tube, but an O-ring 702 for preventing leakage is attached to the outer periphery of the check valve, and the groove is provided in the central tube. It can also be installed to install. In addition, there is a method of pressing and fixing the weir 703 after mounting the O-ring 702, but in this case, it is necessary to mount the check valve so that the check valve is firmly fixed in the flow direction. Moreover, in the fixing method in FIG.7 (c), it is desirable to fix with an adhesive etc. on the side without a weir after attachment.

  However, the separation membrane element of the present invention is used for brine desalination and ultrapure water applications in view of the angle between the central tube and the check valve formed when the check valve is installed and the size of the check valve. In particular, it is desirable to use in applications where the amount of processing medium is small.

DESCRIPTION OF SYMBOLS 101: Spiral type separation membrane element 102: Separation membrane 103: To-be-processed medium permeation flow path material 104: Processing medium permeation flow path material 105: Center pipe 201: Spiral type separation membrane element 202: Center pipe 203: Check valve 301: Spiral type separation membrane element 302: Pressure vessel (vessel)
303: Brine seal 304: Central pipe 305: Check valve 401: Separation membrane element 402: Pressure vessel 403: Central pipe 404: Brine seal 405: Check valve I: Upstream in the separation membrane element II: Downstream in the separation membrane element 501 : Separation membrane 502: Center pipe 503: Outer type connection connector 504: O-ring 505: Inner type connection connector 601: Inner type connection connector 602: Center pipe 701: Adhesive 702: O-ring 703: Weir

Claims (4)

  A membrane unit including a separation membrane that separates components of a medium to be processed is wound around a central tube having a plurality of holes in a spiral shape, and the outer periphery of the wound membrane unit is covered with an outer package. Separation membrane using a central tube provided with a check valve on the downstream side of the most downstream hole of the plurality of holes on the side surface of the central tube as the central tube, wherein the central tube has a structure in which a circular body is formed. element.   A separation membrane module comprising one or more separation membrane elements according to claim 1 loaded in a pressure vessel.   A separation membrane module in which one or more separation membrane elements are loaded in a pressure vessel in series with respect to the flow direction, and the separation membrane element according to claim 1 is loaded on the most downstream side with respect to the flow direction of the separation membrane module. A separation membrane module.   A fluid treatment method for treating a fluid to be treated on the surface of the separation membrane by filtration, forward osmosis or reverse osmosis using the separation membrane element according to claim 1.