Hollow fiber membrane module

Abstract

Provided is a hollow fiber membrane module in which the load on a hollow fiber membrane can be minimized.　A hollow fiber membrane module 10 comprising: a plurality of hollow fiber membranes 220; a case 100 in which the plurality of hollow fiber membranes 220 are accommodated within an accommodation space of which the two ends are open; and a pair of sealing fixing parts 231, 232 that seal gaps between the plurality of hollow fiber membranes 220 in a state in which the hollow interiors of the plurality of hollow fiber membranes 220 are opened, the pair of sealing fixing parts 231, 232 being located on one side and the other side of the case 100, the hollow fiber membrane module 10 being characterized by comprising a holding member 210 that is provided inside the case 100 and holds the plurality of hollow fiber membranes 220, and the plurality of hollow fiber membranes 220 being fixed to the holding member 210 by the pair of sealing fixing parts 231, 232.

Description

Hollow fiber membrane module

[0001] The present invention relates to a hollow fiber membrane module.

[0002] Humidifiers used in fuel cells for automobiles are equipped with hollow fiber membrane modules. In such devices, there is an increasing demand for high-power systems, and the hollow fiber membrane modules tend to become larger. A hollow fiber membrane module according to the prior art will be described with reference to FIG. 7 . FIG. 7 is a schematic diagram of a hollow fiber membrane module according to the prior art, where FIG. 7(a) is a front view of the hollow fiber membrane module and FIG. 7(b) is a cross-sectional view taken along the line BB in FIG. 7(a).

[0003] A hollow fiber membrane module 500 according to the prior art comprises a hollow fiber membrane module main body 510 and a pair of cover members 520, 530 attached to the hollow fiber membrane module main body 510. The hollow fiber membrane module main body 510 comprises a case 511 and a plurality of hollow fiber membranes 512 housed within the case 511. The case 511 has an interior housing that is open at both ends, and the plurality of hollow fiber membranes 512 are housed within this housing interior. The pair of cover members 520, 530 are provided with openings 521, 531, respectively, which serve as inlets and outlets for fluids. The case 511 also has a plurality of through-holes 511a that communicate the internal spaces of the cover members 520, 530 with the housing interior of the case 511.

[0004] Furthermore, the hollow fiber membrane module body 510 is provided with a pair of seal fixing parts 513, 514 at one end and the other end of the case 511, which seal the gaps between the plurality of hollow fiber membranes 512 while leaving the hollow interiors of the plurality of hollow fiber membranes 512 open. The annular gaps between the inner peripheral surface of the case 511 and the pair of seal fixing parts 513, 514 are sealed with liquid gaskets.

[0005] In the hollow fiber membrane module 500 configured as described above, for example, wet gas is caused to flow from opening 521 to opening 531 so as to pass through the outside of the plurality of hollow fiber membranes 512, and dry gas is caused to flow from the sealing and fixing part 514 side to the sealing and fixing part 513 side so as to pass through the hollow interiors of the plurality of hollow fiber membranes 512, whereby the dry gas is humidified and the wet gas is dried.

[0006] As described above, as hollow fiber membrane modules become larger, the flow rate of fluid increases, the pressure-receiving area of ​​the hollow fiber membrane module becomes larger, and the pressure it receives increases. Therefore, in the past, to prevent the pair of seal fasteners 513, 514 from misaligning relative to the case 511, an annular groove 511b was provided on the inner peripheral surface of the case 511, and the annular protrusions on the outer periphery of the pair of seal fasteners 513, 514 were configured to engage with the groove. However, although a resin case 511 can be molded using a mold, it is difficult to form the annular groove 511b by molding, especially in the case of a large case 511. Therefore, the annular groove 511b was formed by cutting or other processes after resin molding. Furthermore, in the conventional structure, the pair of seal fasteners 513, 514 can move slightly independently in a direction parallel to the hollow fiber membrane 512. Therefore, the hollow fiber membrane 512 is pulled or crushed, which easily increases the load and may cause damage.

[0007] JP 2015-181986 A

[0008] The present invention provides a hollow fiber membrane module that can suppress the load on the hollow fiber membranes.

[0009] The present invention employs the following means to solve the above problems.

[0010] The hollow fiber membrane module of the present invention comprises: a plurality of hollow fiber membranes; a case having openings at both ends and containing the plurality of hollow fiber membranes; and a pair of sealing and fixing parts at one end and the other end of the case for sealing gaps between the plurality of hollow fiber membranes while leaving the hollow interiors of the plurality of hollow fiber membranes open; and is characterized in that the module further comprises a holding member provided within the case and holding the plurality of hollow fiber membranes, and the plurality of hollow fiber membranes are fixed to the holding member by the pair of sealing and fixing parts.

[0011] According to the present invention, since the pair of seal fixing parts are fixed to the holding member, the pair of seal fixing parts are prevented from moving independently of each other, and therefore the hollow fiber membrane is prevented from being pulled or crushed. The annular gap between the pair of seal fixing parts and the case may be sealed by a seal part made of an elastic material.

[0012] The holding member may include a pair of plate-like portions arranged to sandwich the plurality of hollow fiber membranes, and a connecting portion connecting the pair of plate-like portions.

[0013] The pair of plate-like portions may be provided with a plurality of through holes that serve as passages for fluid passing outside the hollow fiber membranes.

[0014] As described above, according to the present invention, the load on the hollow fiber membrane can be reduced.

[0015] Fig. 1 is a schematic diagram of a hollow fiber membrane module according to an embodiment of the present invention. Fig. 2 is a schematic diagram of a hollow fiber membrane module according to an embodiment of the present invention. Fig. 3 is a schematic diagram of a holding member according to an embodiment of the present invention. Fig. 4 is a manufacturing process diagram of a hollow fiber membrane module according to an embodiment of the present invention. Fig. 5 is a manufacturing process diagram of a hollow fiber membrane module according to an embodiment of the present invention. Fig. 6 is a schematic diagram showing an application example of a hollow fiber membrane module according to an embodiment of the present invention. Fig. 7 is a schematic diagram of a hollow fiber membrane module according to the prior art.

[0016] The following detailed description of the present invention will be given by way of example with reference to the accompanying drawings, although the dimensions, materials, shapes, relative positions, etc. of the components described in the examples are not intended to limit the scope of the present invention unless otherwise specified.

[0017] (Example) A hollow fiber membrane module according to an example of the present invention will be described with reference to Figures 1 to 5. Figure 1 is a schematic diagram of a hollow fiber membrane module according to an example of the present invention, where Figure 1(a) is a front view of the hollow fiber membrane module and Figure 1(b) is a plan view of the hollow fiber membrane module. Figure 2 is a schematic diagram of a hollow fiber membrane module according to an example of the present invention, where Figure 2(a) is a side view of the hollow fiber membrane module and Figure 2(b) is a cross-sectional view taken along A1-A1 in Figure 1(a) (a cross-sectional view taken along A2-A2 in Figure 1(b)). Figure 3 is a schematic diagram of a holding member according to an example of the present invention, where Figure 3(a) is a front view of the holding member, Figure 3(b) is a plan view of the holding member, and Figure 3(c) is a side view of the holding member. Figures 4 and 5 are diagrams illustrating the manufacturing process of a hollow fiber membrane module according to an example of the present invention. 4(a) is a front view of an intermediate product during the manufacturing process, and FIGS. 4(b), 4(c) and 5 are partial cross-sectional views of the intermediate product during the manufacturing process (corresponding to the A1-A1 cross-sectional view in FIG. 1(a) (the A2-A2 cross-sectional view in FIG. 1(b))).

[0018] <Hollow Fiber Membrane Module> The hollow fiber membrane module 10 according to this embodiment includes a case 100 and a hollow fiber membrane unit 200 housed in the case 100. The case 100 can be made of a highly rigid resin material or the like. The case 100 includes a cylindrical case body 110 and a pair of pipes 111, 112 integrally formed with the case body 110. The case body 110 is open at both ends, and its interior serves as a housing interior for housing multiple hollow fiber membranes 220. The case body 110 according to this embodiment is composed of a pair of flat plate-shaped portions and a pair of curved portions connecting the two sides of the flat plate-shaped portions, and has an oval shape when viewed from the front. The pair of pipes 111, 112 connect the outside of the case 100 with the inside of the case body 110, forming a passage for fluid flowing outside the multiple hollow fiber membranes 220. The pair of pipes 111 and 112 are provided on the outer walls of a pair of flat plate-shaped portions of the case body 110, respectively.

[0019] The hollow fiber membrane unit 200 includes a holding member 210, a plurality of hollow fiber membranes 220 held by the holding member 210, and a pair of sealing and fixing parts 231, 232. The pair of sealing and fixing parts 231, 232 are configured to seal the gaps between the plurality of hollow fiber membranes 220 at one end and the other end of the case 100 while leaving the hollow interiors of the plurality of hollow fiber membranes 220 open. Polyphenylsulfone (PPSU) can be suitably used as the material for the hollow fiber membranes 220, and epoxy resin can be suitably used as the material for the sealing and fixing parts 231, 232.

[0020] The holding member 210 can be made of a resin material. The holding member 210 includes a pair of plate-shaped portions 211, 212 that sandwich the plurality of hollow fiber membranes 220, and a connecting portion 215 that connects the pair of plate-shaped portions 211, 212. The pair of plate-shaped portions 211, 212 are provided with a plurality of through-holes 211a, 212a that serve as passages for fluid passing outside the plurality of hollow fiber membranes 220. The pair of plate-shaped portions 211, 212 are configured to face a pair of flat plate-shaped portions of the case body 110, respectively, when the holding member 210 is housed inside the case (inside the case body 110). The pair of plate-shaped portions 211, 212 form a passage for fluid flowing outside the plurality of hollow fiber membranes 220 between the inner circumferential surface (the inner circumferential surfaces of the pair of flat plate-shaped portions) of the case 100 (case body 110) and the plurality of hollow fiber membranes 220. This passage allows fluid to flow throughout the plurality of hollow fiber membranes 220 housed between the pair of plate-like portions 211, 212. Furthermore, the pair of plate-like portions 211, 212 are each provided with a plurality of pin-shaped support portions 213, 214. These support portions 213, 214 abut against the pair of flat plate-like portions of the case body 110, thereby suppressing deformation of the pair of plate-like portions 211, 212. Furthermore, a stable gap is maintained between the pair of flat plate-like portions of the case body 110 and the pair of plate-like portions 211, 212.

[0021] <Method for manufacturing hollow fiber membrane module> The method for manufacturing the hollow fiber membrane module 10 will be described in the order of the manufacturing steps. First, the holding member 210 is inserted into the interior of the case 100 (case body 110). Then, a plurality of hollow fiber membranes 220 are filled between the pair of plate-like portions 211, 212 of the holding member 210, on both sides of the connecting portion 215. Figure 4(a) shows the state after a plurality of hollow fiber membranes 220 have been filled. Next, seal fixing portions 231, 232 are formed. While Figures 4 and 5 show the process for forming the seal fixing portion 232, the same applies to the seal fixing portion 231.

[0022] First, a jig 400 for filling a liquid potting material such as epoxy resin is attached to the end of the case body 110. In this state, the liquid potting material 232a is filled (see FIG. 4(b)). The liquid potting material 232a may be poured through an injection port provided in the jig 400, or may be poured through a tube or the like in the piping 111. Furthermore, from the time the liquid potting material 232a is poured until the potting material 232a hardens, the liquid level of the potting material 232a can be maintained at a predetermined position by applying centrifugal force or the like.

[0023] After the potting material 232a has hardened, the jig 400 is removed (see FIG. 4(c)). Then, a portion of the hardened potting material 232a is cut off along with a portion of the tip ends of the hollow fiber membranes 220. The dashed-dotted line C in FIG. 4(c) indicates the cut surface. As a result, the hollow interiors of the hollow fiber membranes 220 are opened, while the gaps between the hollow fiber membranes 220 are sealed. This results in the formation of a sealing and fixing portion 232 (see FIG. 5(a)). Note that in this embodiment, both ends of the holding member 210 are configured to have a complex structure. This allows the sealing and fixing portion 232 to be hooked onto the end of the holding member 210 even if forces act on the hardened sealing and fixing portion 232 in various directions. For example, as shown in FIG. 5(a), a portion of the sealing and fixing portion 232 is present on the end face side and the interior side of the case 100 via the portions of the end of the holding member 210 that protrude upward and downward in the figure. Therefore, the sealing and fixing portion 232 does not shift in the left-right direction in the figure relative to the holding member 210. Therefore, the sealing and fixing portion 232 does not come off the holding member 210.

[0024] After the sealing and fixing portion 232 is formed, the adhesive portion between the case body 110 and the sealing and fixing portion 232 is peeled off. For example, the intermediate product after the sealing and fixing portion 232 is provided can be placed in a constant temperature bath and heated for a predetermined period of time to peel off the adhesive portion between the case body 110 and the sealing and fixing portion 232. Thereafter, a liquid gasket 310 such as a silicone adhesive is injected into the annular gap between the case body 110 and the sealing and fixing portion 232 (see FIG. 5B). As the liquid gasket 310 hardens, the annular gap between the case body 110 and the sealing and fixing portion 232 is sealed. In other words, the annular gap between the sealing and fixing portion 232 and the case 100 (case body 110) is sealed by the hardened liquid gasket 310 (a sealing portion made of an elastic material).

[0025] Here, we will briefly explain why the adhesive portion between the case body 110 and the seal fixing portion 232 is peeled off and the annular gap therebetween is sealed with the liquid gasket 310. Because the case body 110 and the seal fixing portion 232 have different linear expansion coefficients, a force that peels the case body 110 and the seal fixing portion 232 away from each other is generated depending on the ambient temperature. As a result, there is a risk that the adhesive portion between the case body 110 and the seal fixing portion 232 will peel off over time. In particular, when the hollow fiber membrane module 10 is large, the difference in linear expansion coefficients cannot be ignored. Therefore, in this embodiment, a configuration is adopted in which the adhesive portion between the case body 110 and the seal fixing portion 232 is peeled off and the annular gap therebetween is sealed with the liquid gasket 310, which remains elastically deformable even after hardening.

[0026] <Application Examples of the Hollow Fiber Membrane Module> An application example of the hollow fiber membrane module 10 according to this embodiment will be described. The hollow fiber membrane module 10 according to this embodiment can be used as a humidifier or a dehumidifier. This will be briefly described.

[0027] The hollow fiber membrane module 10 includes an intra-membrane flow path that passes through the interior of the hollow fiber membranes 220 and an extra-membrane flow path that passes outside the hollow fiber membranes 220. For example, the intra-membrane flow path is configured so that dry gas flows from one end of the case 100 through the hollow interiors of the hollow fiber membranes 220 to the other end of the case 100 (see the solid arrow in FIG. 2(b)). Furthermore, for example, the extra-membrane flow path is configured so that wet gas, which has a higher humidity than the dry gas, flows from the pipe 111 through the interior of the case 100 to the pipe 112 (see the dotted arrow in FIG. 2(b)).

[0028] Although not specifically shown, lids equipped with inlets and outlets for allowing fluid to flow through the intra-membrane flow paths are attached to both ends of the case 100. These lids more reliably suppress movement of the hollow fiber membrane unit 200 relative to the case 100.

[0029] With the above configuration, the membrane separation action of the hollow fiber membrane causes moisture in the wet gas to move into the dry gas, thus humidifying the dry gas and dehumidifying the wet gas, making the device usable as both a humidifier and a dehumidifier.

[0030] The hollow fiber membrane module 10 according to this embodiment can be suitably used as a humidifier for humidifying an electrolyte membrane included in a fuel cell 50. A configuration in which the hollow fiber membrane module 10 is used as such a humidifier will be described with reference to FIG. 6 . As shown in the figure, dry air is sent to the intra-membrane flow path of the hollow fiber membrane module 10 by a compressor 60 (see arrow R1). As described above, the dry air flowing through the intra-membrane flow path is humidified and discharged from the hollow fiber membrane module 10. This humidified wet air is sent to the fuel cell 50 (see arrow R2). This keeps the electrolyte membrane included in the fuel cell 50 moist. The wet air generated within the fuel cell 50 is then sent to the extra-membrane flow path of the hollow fiber membrane module 10 (see arrow R3), and the dry air dehumidified by the membrane separation action of the hollow fiber membrane is discharged from the hollow fiber membrane module 10 (see arrow R4). Although the temperature of the moist air generated in the fuel cell 50 is high, the temperature of the dry air sent from the compressor 60 is low, and therefore the temperature of the moist air discharged from the hollow fiber membrane module 10 is low. In this way, the hollow fiber membrane module 10 also exhibits a heat exchange function.

[0031] <Advantages of the hollow fiber membrane module according to this embodiment> According to the hollow fiber membrane module 10 according to this embodiment, the pair of seal fastening parts 231, 232 are fixed to the holding member 210, which prevents the pair of seal fastening parts 231, 232 from moving independently. This prevents the hollow fiber membranes 220 from being pulled or crushed. In this way, by reducing the load on the hollow fiber membranes 220, damage to the hollow fiber membranes 220 can be prevented.

[0032] Furthermore, this embodiment does not employ a structure in which an annular groove or the like is provided on the inner circumferential surface of the case body to hook part of the seal fixing part, so cutting or the like of the case body is not required, and manufacturing is easy.

[0033] (Other) In the above-described holding member 210, it is also preferable to provide a hollow portion 215a inside the connecting portion 215, thereby connecting the passage between the plate-shaped portion 211 and the case body 110 and the passage between the plate-shaped portion 212 and the case body 110. By adopting such a configuration, a passage is formed that leads directly from the pipe 111 to the pipe 112 without passing through the area filled with multiple hollow fiber membranes 220. This reduces pressure loss and the load on the hollow fiber membranes 220, for example, when flowing wet gas from the pipe 111 to the pipe 112. Of course, depending on the usage conditions, the hollow portion 215a may not necessarily be provided. In the above examples, the hollow fiber membrane module 10 was described as being used as a humidifier or dehumidifier. However, the hollow fiber membrane module of the present invention may also be used in other applications, such as filtration devices (e.g., devices that perform crossflow filtration).

[0034] 10: Hollow fiber membrane module 100: Case 110: Case body 111, 112: Piping 200: Hollow fiber membrane unit 210: Holding member 211, 212: Plate-shaped portion 211a, 212a: Through-hole 213, 214: Support portion 215: Connecting portion 215a: Cavity portion 220: Hollow fiber membrane 231, 232: Sealing and fixing portion 232a: Potting material 310: Liquid gasket 400: Jig

Claims

1. A plurality of hollow fiber membranes; a case having both ends open and containing the plurality of hollow fiber membranes; a pair of sealing fixing parts at one end side and the other end side of the case, which seal gaps between the plurality of hollow fiber membranes while leaving the hollow interiors of the plurality of hollow fiber membranes open; A hollow fiber membrane module comprising: a holding member provided in the case and holding the plurality of hollow fiber membranes; The holding member is a pair of plate-like portions disposed so as to sandwich the plurality of hollow fiber membranes; a connecting portion that connects the pair of plate-shaped portions; Equipped with a hollow fiber membrane module characterized in that the plurality of hollow fiber membranes are sandwiched between the pair of plate-like portions and arranged on both sides of the connecting portion, and are fixed to the holding member by the pair of sealing fixing portions.

2. 2. The hollow fiber membrane module according to claim 1, wherein an annular gap between the pair of sealing fixing parts and the case is sealed by a seal part made of an elastic material.

3. 2. The hollow fiber membrane module according to claim 1, wherein the pair of plate-like portions are provided with a plurality of through-holes that serve as passages for fluid passing outside the plurality of hollow fiber membranes.