Hollow fiber membrane module and dehumidification / humidification device

Abstract

Provided are a hollow fiber membrane module and a dehumidification and humidification device, capable of enhancing the contribution rate of a hollow fiber membrane to the membrane separation function and improving dehumidification and humidification performance.　The present invention is characterized in that: an outer case 100 is provided with a double tube part 120 that forms, on one end side, an annular space K on the outer side in the radial direction from an annular space S, a communication part 121 that communicates between the annular space S and said one end side of the annular space K, and an outlet part 122 that communicates between the annular space K and the outside of the outer case 100; and an inner case 200 is provided with a hollow part that opens on the other end side, and multiple windows 221 that communicate between the hollow part and the annular space S.

Description

[Technical field]

[0001] The present invention relates to a hollow fiber membrane module and a dehumidification / humidification device. [Background technology]

[0002] A hollow fiber membrane module provided in a humidifier for a fuel cell is required to have improved humidification performance, suppressed pressure loss, and compact size. To achieve these, it is necessary to increase the contribution rate of the hollow fiber membrane provided in the case to the membrane separation action. A technique that meets these requirements by making the case of the hollow fiber membrane module into a double case is known. Such a conventional hollow fiber membrane module will be described with reference to FIG. 3. FIG. 3 is a schematic cross-sectional view of a conventional hollow fiber membrane module.

[0003] The illustrated hollow fiber membrane module 500 includes a cylindrical outer case 510, an inner case 520 disposed inside the outer case 510, and a plurality of hollow fiber membranes 530 provided in an annular gap between the outer case 510 and the inner case 520. The hollow fiber membrane module 500 also includes a pair of sealing and fixing parts 541, 542 and a pair of buffer parts 551, 552. The sealing and fixing parts 541, 542 serve to seal the annular gaps at one end side and the other end side of the outer case 510 and the inner case 520, respectively, while leaving the hollow interiors of the hollow fiber membranes 530 open, and to fix the plurality of hollow fiber membranes 530 to the outer case 510 and the inner case 520.

[0004] Outer case 510 is provided with outlet 511 at at least one location in the circumferential direction, located toward one end, which connects the annular gap with the outside of outer case 510. In a portion where outlet 511 is not provided, part 512 of the inner circumferential surface of outer case 510 has a larger inner diameter than other portions so as not to come into contact with the outer circumferential surface of the bundle of hollow fiber membranes 530.

[0005] Further, a partition wall 521 is provided inside the inner case 520, and a plurality of windows 522 are provided on the other end side of this partition wall 521, which communicate the hollow space inside the inner case 520 with the above-mentioned annular gap.

[0006] For the hollow fiber membrane module 500 configured as above, wet gas is supplied to the hollow inside of the inner case 520, and dry gas is supplied to the hollow inside of each hollow fiber membrane 530 from the sealing and fixing part 541 side. As a result, as shown by the solid arrow in the figure, the wet gas enters the above-mentioned annular gap from the multiple windows 522, passes outside the hollow fiber membrane 530, and flows from the outlet part 511 to the outside of the outer case 510. In addition, the dry gas flows through the inside of the hollow fiber membrane 530 from the sealing and fixing part 541 on one end side to the sealing and fixing part 542 on the other end side. As a result, the moisture in the wet gas moves to the dry gas side due to the membrane separation action of the hollow fiber membrane 530, and the dry gas is humidified.

[0007] In the case of a typical hollow fiber membrane module, multiple hollow fiber membranes are provided in a single cylindrical case, and the case is provided with an inlet and an outlet for wet gas, so that the hollow fiber membranes located near the center of the case tend not to contribute much to the membrane separation action. In contrast, in the case of the hollow fiber membrane module 500 according to the conventional example shown in Figure 3 above, the multiple hollow fiber membranes 530 can all contribute to the membrane separation action, making it possible to meet the above-mentioned requirements.

[0008] However, even in the case of the hollow fiber membrane module 500 described above, the wet gas flow that passes through the portion that is the shortest distance from the window 522 to the outlet 511 tends to become mainstream. Therefore, it was found that, among the multiple hollow fiber membranes 530, the region away from the outlet 511 (near X1 in the figure) and the region on one end side and radially inward (near X2 in the figure) are unlikely to contribute to the membrane separation action. Thus, there is still room for improvement. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] JP 2002-147802 A [Patent Document 2] JP 2005-265196 A Summary of the Invention [Problem to be solved by the invention]

[0010] An object of the present invention is to provide a hollow fiber membrane module and a dehumidifier that make it possible to improve the contribution rate of the hollow fiber membrane to the membrane separation action and to improve the dehumidification / humidification performance. [Means for solving the problem]

[0011] The present invention employs the following means to solve the above problems.

[0012] That is, the hollow fiber membrane module of the present invention has the following features: A cylindrical outer case, an inner case disposed inside the outer case; A plurality of hollow fiber membranes provided in an annular gap between the outer case and the inner case; a pair of sealing and fixing parts that seal the annular gaps at one end side and the other end side of the outer case and the inner case while leaving the hollow interiors of the hollow fiber membranes open, and that fix the plurality of hollow fiber membranes to the outer case and the inner case; A hollow fiber membrane module comprising: The outer case is provided with a double pipe portion that forms an annular space radially outward of the annular gap at the one end side, and is provided with a communication portion that communicates the annular gap with the one end side of the annular space, and an outlet portion that communicates the annular space with the outside of the outer case, The inner case has a hollow portion that opens to the other end side, The hollow portion includes a widening portion whose width in a direction perpendicular to a direction from the one end side to the other end side increases from the one end side to the other end side, and the widening portion includes The hollow portion is characterized in that a plurality of windows are provided to communicate with the annular gap.

[0013] According to the present invention, the fluid flowing from the hollow portion of the inner case through the window into the annular gap flows from the communication portion toward the annular space and then flows from the outlet portion to the outside of the outer case. This makes it possible to reduce the amount of fluid flowing directly from the window toward the outlet portion. Therefore, it is possible to improve the contribution rate of the hollow fiber membrane to the membrane separation action.

[0014] The communication portion may be provided around the entire periphery.

[0015] This makes it possible to further increase the contribution of the hollow fiber membrane to the membrane separation action.

[0016] The outlet portion may be provided at least at one location in the circumferential direction.

[0017] The inner case may have a widening portion in which the width in a direction perpendicular to the direction from the one end side to the other end side increases from the one end side to the other end side, and the multiple windows may be provided in the widening portion.

[0018] By adopting such a configuration, it is possible to easily make the fluid passing through the outside of the hollow fiber membrane and the fluid passing through the hollow interior of the hollow fiber membrane flow in a countercurrent manner in the vicinity of the window.

[0019] The dehumidifying and humidifying device of the present invention is The hollow fiber membrane module described above, a wet gas supplying device that supplies wet gas to the hollow portion; a dry gas supplying device that supplies a dry gas having a lower humidity than the wet gas from the sealing and fixing portion on the one end side to each hollow interior of the plurality of hollow fiber membranes; The present invention is characterized by comprising:

[0020] The above configurations may be combined as much as possible. Effect of the Invention

[0021] As described above, according to the present invention, it is possible to improve the contribution rate of the hollow fiber membrane to the membrane separation action and to improve the dehumidification / humidification performance. [Brief description of the drawings]

[0022] [Figure 1] FIG. 1 is a plan view of a hollow fiber membrane module according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a schematic diagram of a dehumidifying / humidifying device according to an embodiment of the present invention. [Diagram 3] FIG. 3 is a schematic cross-sectional view of a hollow fiber membrane module according to a conventional example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] Hereinafter, the embodiment of the present invention will be described in detail with reference to the drawings. However, the dimensions, materials, shapes, relative positions, and the like of the components described in the embodiment are not intended to limit the scope of the present invention unless otherwise specified.

[0024] (Example) A hollow fiber membrane module and a dehumidification / humidification device according to an embodiment of the present invention will be described with reference to Fig. 1 and Fig. 2. Fig. 1 is a plan view of a hollow fiber membrane module according to an embodiment of the present invention. Fig. 2 is a schematic configuration diagram of a dehumidification / humidification device according to an embodiment of the present invention. In Fig. 2, the hollow fiber membrane module is shown in a schematic cross-sectional view. The cross-sectional view of this hollow fiber membrane module corresponds to the AA cross-sectional view in Fig. 1.

[0025] <Dehumidifier / humidifier> The dehumidifying / humidifying device according to the present embodiment includes a hollow fiber membrane module 10, a wet gas supplying device 20, and a dry gas supplying device 30. The wet gas supplying device 20 is configured to supply wet gas to the outside of the hollow fiber membrane 300 included in the hollow fiber membrane module 10. The dry gas supplying device 30 is configured to supply dry gas with a lower humidity than the above-mentioned wet gas to each hollow interior of the plurality of hollow fiber membranes 300. As a result, moisture in the wet gas moves to the dry gas side due to the membrane separation action of the hollow fiber membrane 300. Therefore, since the dry gas is humidified and the wet gas is dehumidified, it can be used as both a humidifying device and a dehumidifying device. The dehumidifying / humidifying device according to the present embodiment can be suitably used as a humidifying device for humidifying an electrolyte membrane included in a fuel cell. In this case, the wet air generated in the fuel cell is used as the above-mentioned wet gas. Then, the humidified gas (air) is supplied to the electrolyte membrane included in the fuel cell, so that the electrolyte membrane is maintained in a wet state. Here, as the material of the hollow fiber membrane 300, for example, PPSU (polyphenylsulfone) having the property of permeating moisture by a capillary condensation mechanism by pore size control can be suitably used. When preparing a membrane forming solution (raw material of the hollow fiber membrane), a hollow fiber membrane having hydrophilicity can be obtained by spinning using a membrane forming solution in which PPSU and a hydrophilic polymer (polyvinyl porolidone) are added to a solvent. Nafion (registered trademark), which is a hydrophilic material having the property of permeating moisture by dissolution and diffusion, can also be used. The above-mentioned materials have low elution and high strength, and therefore can be suitably used in dehumidifying and humidifying devices.

[0026] <Hollow fiber membrane module> The hollow fiber membrane module 10 according to this embodiment will be described in more detail. The hollow fiber membrane module 10 includes a cylindrical outer case 100, an inner case 200 disposed inside the outer case 100, and a plurality of hollow fiber membranes 300 disposed in an annular gap S between the outer case 100 and the inner case 200. The hollow fiber membrane module 10 also includes a pair of sealing and fixing parts 410, 420 and a pair of buffer parts 430, 440. The sealing and fixing parts 410, 420 seal the annular gap S at one end side (right side in FIG. 2) and the other end side (left side in FIG. 2) of the outer case 100 and the inner case 200, respectively, while the hollow interior of each hollow fiber membrane 300 is open, and fix the plurality of hollow fiber membranes 300 to the outer case 100 and the inner case 200. These sealing and fixing parts 410, 420 are obtained by hardening a potting material such as an epoxy resin. In addition, the pair of buffer parts 430, 440 are made of a highly flexible material such as silicon. Providing these buffer parts 430, 440 can suppress shaking of the hollow fiber membrane 300 near the seal fixing parts 410, 420, and can suppress damage to the hollow fiber membrane 300 near the interface with the seal fixing parts 410, 420. For convenience, the right side of the hollow fiber membrane module 10 in FIG. 2 will be referred to as "one end" and the left side as "the other end".

[0027] The outer case 100 includes a cylindrical case body 110. In this embodiment, the case body 110 is configured with a substantially cylindrical portion, but the shape is not limited thereto, and various shapes such as a prismatic shape may be adopted. In addition, the outer case 100 is provided with a double pipe portion 120 that forms an annular space K radially outside the annular gap S at one end side. The double pipe portion 120 according to this embodiment is composed of a cylindrical portion 120a whose outer diameter and inner diameter are larger than the outer diameter and inner diameter of the case body 110, and a connecting portion 120b that connects the other end side of the cylindrical portion 120a to the case body 110. Furthermore, the outer case 100 is provided with a communication portion 121 that communicates the annular gap S with one end side of the annular space K, and an outlet portion 122 that communicates the annular space K with the outside of the outer case 100. The communication portion 121 according to this embodiment is provided around the entire circumference. From the viewpoint of increasing the contribution rate of the hollow fiber membrane 300 to the membrane separation action, it is desirable to provide the communication parts 121 around the entire circumference, but it is not necessary to provide them around the entire circumference, and a configuration in which multiple communication parts are provided at intervals in the circumferential direction can also be adopted. Moreover, the outlet part 122 is provided at least at one place in the circumferential direction, and the number of outlet parts can be appropriately set depending on the dimensions of the hollow fiber membrane module 10 and the usage environment.

[0028] The inner case 200 is configured such that a partition wall 210 is provided inside a cylindrical member. As a result, the inner case 200 is configured to have a hollow portion that opens to the other end side. In addition, the inner case 200 is provided with a widening portion 220 in which the width in a direction perpendicular to the direction from one end side to the other end side increases from one end side to the other end side. The inner and outer peripheral surfaces of the widening portion 220 according to this embodiment are configured as tapered surfaces. However, the shapes of the inner and outer peripheral surfaces of the widening portion 220 are not limited to tapered surfaces, and other shapes can be adopted as long as the width in a direction perpendicular to the direction from one end side to the other end side is gradually increased. For example, a curved surface in which the cross-sectional shape cut along a plane including the central axis is a curved line, or a shape in which the cross-sectional shape is a pyramidal surface can be adopted.

[0029] In the inner case 200, the widened portion 220 is provided with a plurality of windows 221 that communicate the hollow portion with the annular gap S. The inner diameter and the outer diameter of the inner case 200 on the one end side of the widened portion 220 are configured to be constant. In other words, the inner case 200 is configured with a cylindrical portion.

[0030] For the hollow fiber membrane module 10 configured as above, wet gas is supplied to the hollow part of the inner case 200 by the wet gas supplying device 20. In addition, dry gas is supplied to the hollow interior of each of the plurality of hollow fiber membranes 300 from the sealing fixing part 410 on one end side by the dry gas supplying device 30. This point will be described in more detail.

[0031] The wet gas is supplied from the wet gas supply device 20 to the hollow portion (arrow A1 in FIG. 2), and enters the annular gap S from the windows 221 (arrow A2). The wet gas that has entered the annular gap S passes outside the hollow fiber membrane 300, flows from the communication portion 121 to the annular space K (arrow A3), and then flows from the outlet portion 122 to the outside of the outer case 100. The dry gas is supplied from the seal fixing portion 410 on one end side to the hollow interior of each of the hollow fiber membranes 300 (arrow B1) by the dry gas supply device 30, and flows inside each of the hollow fiber membranes 300 (arrow B2). Then, it is discharged from the seal fixing portion 420 on the other end side (arrow B3). In the above process, the moisture in the wet gas moves to the dry gas side due to the membrane separation action of the hollow fiber membrane 300, and the dry gas is humidified and the wet gas is dehumidified.

[0032] <Advantages of the hollow fiber membrane module and the dehumidification / humidification device according to the present embodiment> According to this embodiment, the wet gas is configured to flow from the multiple windows 221 provided in the inner case 200 to the outlet portion 122 provided in the outer case 100. Therefore, it is possible to make the multiple hollow fiber membranes 300 provided in the annular gap S between the inner case 200 and the outer case 100 contribute to the membrane separation action in their entirety. In this embodiment, the fluid flowing from the hollow portion of the inner case 200 through the windows 221 to the annular gap S flows from the communication portion 121 toward the annular space K, and then flows from the outlet portion 122 to the outside of the outer case 100. This makes it possible to suppress the amount of fluid flowing directly from the windows 221 toward the outlet portion 122. Therefore, it is possible to improve the contribution rate of the hollow fiber membranes 300 to the membrane separation action.

[0033] In this embodiment, the communication portion 121 is provided over the entire circumference, which can further increase the contribution of the hollow fiber membrane 300 to the membrane separation action.

[0034] Furthermore, the inner case 200 according to this embodiment is provided with a widening section 220 in which the width in a direction perpendicular to the direction from one end side to the other end side increases from one end side to the other end side, and a plurality of windows 221 are provided in this widening section 220. Therefore, in the vicinity of the windows 221, it is possible to easily make the fluid passing through the outside of the hollow fiber membrane 300 and the fluid passing through the hollow interior of the hollow fiber membrane 300 flow in a countercurrent manner. This can enhance the membrane separation action and improve the dehumidification / humidification performance.

[0035] (others) In the above embodiment, a configuration has been shown in which the widened portion 220 is provided in the inner case 200 and multiple windows 221 are provided in the widened portion 220. However, the present invention also includes a configuration in which the inner case is not provided with a widened portion and multiple windows are provided in a portion of a constant width. For example, the present invention can also be applied to an inner case 520 having multiple windows 522 as shown in FIG. 3 described in the prior art. [Explanation of symbols]

[0036] 10 Hollow fiber membrane module 20 Wet gas supply device 30 Dry gas supply device 100 Outer case 110 Case body 120 Double pipe section 120a Cylindrical part 120b Connection part 121 Communication part 122 Exit section 200 Inner Case 210 Bulkhead 220 Widening section 221 Window 300 Hollow fiber membrane 410,420 Sealing fixing part 430,440 Buffer K annular space S Annular Gap

Claims

1. A cylindrical outer case, an inner case disposed inside the outer case; A plurality of hollow fiber membranes provided in an annular gap between the outer case and the inner case; a pair of sealing and fixing parts that seal the annular gaps at one end side and the other end side of the outer case and the inner case while leaving the hollow interiors of the hollow fiber membranes open, and that fix the plurality of hollow fiber membranes to the outer case and the inner case; A hollow fiber membrane module comprising: The outer case is provided with a double pipe portion that forms an annular space radially outward of the annular gap at the one end side, and is provided with a communication portion that communicates the annular gap with the one end side of the annular space, and an outlet portion that communicates the annular space with the outside of the outer case, The inner case has a hollow portion that opens to the other end side, the hollow portion includes a widening portion whose width in a direction perpendicular to the direction from the one end side to the other end side increases from the one end side to the other end side, and the widening portion is provided with a plurality of windows connecting the hollow portion to the annular gap.

2. 2. The hollow fiber membrane module according to claim 1, wherein the communication portion is provided around the entire periphery.

3. 3. The hollow fiber membrane module according to claim 1, wherein the outlet portion is provided at least at one location in the circumferential direction.

4. A hollow fiber membrane module according to any one of claims 1 to 3, a wet gas supplying device that supplies wet gas to the hollow portion; a dry gas supplying device that supplies a dry gas having a lower humidity than the wet gas from the sealing and fixing portion on the one end side to each hollow interior of the plurality of hollow fiber membranes; A dehumidifying and humidifying device comprising:

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