Hollow fiber membrane module

Abstract

To provide a hollow fiber membrane module which realizes both a low pressure loss and a high module processing performance and further can be used for a long time by preventing a decrease in durability due to the curvature of a hollow fiber membrane.SOLUTION: A hollow fiber membrane module 1 encloses an outer peripheral part of a fiber bundle being a bundle of a plurality of hollow fiber membranes 2 with a cover 4. The fiber bundle is a bundle of five or more hollow fiber membranes with the attachment of couplers 5 at both ends. The hollow fiber membrane module comprises a header 7 forming one set by two or more fitted to the couplers via a seal member 10. The plurality of fiber bundles are fitted with the header, wherein the fiber bundles are arranged with spaces between adjacent fiber bundles, and the couplers and the hollow fiber membranes are fixed by means of a potting material to put them together, and to enclose the outer peripheral parts of the plurality of sets of fiber bundles with the cover, the cover being opened by 50% or more on a pair of opposite faces, and at least a portion of the couplers being buried in the header with the seal member attached to a buried portion.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a hollow fiber membrane module for use in humidification or dehumidification. [Background technology]

[0002] In recent years, the use of functional fiber materials, including hollow fiber membranes, has progressed, and hollow fiber membranes are now being applied to humidification modules that moisturize the ion exchange membranes of fuel cells and dehumidification modules in air conditioners that remove humidity from indoor spaces.

[0003] Typically, this type of hollow fiber membrane module is mounted in a box-shaped housing for connection to external piping, with multiple hollow fiber membranes arranged side by side. The hollow fiber membrane module body has a structure in which a hollow fiber membrane bundle is housed inside a cylindrical container, and at both ends, the gaps between the hollow fiber membranes and the hollow fiber membranes and the inner diameter of the cylindrical container are fixed with a sealant. The cross sections of both ends of the hollow fiber membranes are open, forming a first flow path through the interior of the hollow fiber membranes. Furthermore, the side of the cylindrical container has an inlet hole and an outlet hole, forming a second flow path outside the hollow fiber membranes. In the second flow path, the treatment fluid enters through the inlet hole, passes through the gaps between the hollow fiber membranes contained in the cylindrical container, and is then discharged through the outlet hole. In the case of dehumidification applications in air conditioners, the inlet hole and the outlet hole are provided on opposing surfaces of the side wall of the hollow fiber membrane module, and the second flow path is arranged perpendicular to the axial direction of the hollow fiber membranes.

[0004] In addition, the treatment fluid passing through the second flow path is generally outside air in the case of dehumidification applications in air conditioners, and the gas in the second flow path is dehumidified by transferring moisture between the second flow path and the humidity-control liquid flowing in the first flow path via the wall surface of the hollow fiber membrane. Therefore, in order to improve dehumidification efficiency, it is important that the outside air flowing into the hollow fiber membrane module can reach all of the hollow fibers installed in the hollow fiber membrane module.

[0005] Furthermore, if the hollow fiber membrane in the cylindrical container is loose and curved, stress will be concentrated at the curved area, reducing durability during long-term use, so the hollow fiber membrane in the cylindrical container must be fixed straight and without loosening.

[0006] Typically, to fabricate the hollow fiber membrane module described above, a bundle of hollow fiber membranes is inserted axially through the opening of a cylindrical container and then placed inside the cylindrical container. In a hollow fiber membrane module with a high packing density, multiple hollow fiber membranes are bundled together into a single hollow fiber membrane bundle, and the outer periphery of the hollow fiber membrane bundle is squeezed before being inserted into the cylindrical container, preventing the hollow fiber membranes from moving freely. Therefore, if the hollow fiber membrane bundle can be squeezed without any disturbances, such as meandering, a hollow fiber membrane module with straight, aligned hollow fiber membranes inside the cylindrical container can be fabricated. However, when a process fluid is passed through the completed hollow fiber membrane module, the densely packed hollow fiber membranes result in increased flow resistance toward the inner layer of the hollow fiber membrane bundle. Therefore, most of the process fluid passes through the surface layer of the hollow fiber membrane bundle, where pressure loss is low, and does not reach the inner layer of the hollow fiber membrane bundle, where pressure loss is high. In this case, the hollow fiber membranes arranged in the inner layer portion of the hollow fiber membrane bundle are not used effectively, and the treatment performance of the module is significantly reduced.

[0007] Conversely, in hollow fiber membrane modules with low packing density, the hollow fiber membranes can move freely within the cylindrical container. This can lead to biasing of the hollow fiber membranes to one side of the cylindrical container during the hollow fiber membrane module fabrication stage, resulting in a large gap between the hollow fiber membrane bundle and the cylindrical container. When a process fluid is passed through a hollow fiber membrane module fabricated in this state, most of the process fluid passes through the gap between the hollow fiber membrane bundle and the cylindrical container, which has low pressure loss. This results in most of the process fluid passing through the module without contacting the hollow fiber membranes, significantly reducing the module's processing performance. Furthermore, when some hollow fiber membranes become biased within the cylindrical container, they move while meandering or sagging. Therefore, when they are fixed with a sealing material in a subsequent process, the hollow fiber membranes become curved in the completed hollow fiber membrane module. Stress is concentrated at the curved points of the curved hollow fiber membranes, creating a high load, reducing their durability during long-term use and ultimately shortening the life of the hollow fiber membrane module.

[0008] Here, as a means for allowing the treatment fluid to reach the inner layer of the hollow fiber membrane bundle loaded in the hollow fiber membrane module, it has been proposed to prepare multiple small hollow fiber membrane modules by placing multiple hollow fiber membranes in a small diameter cylindrical container, and to arrange these small hollow fiber membrane modules with gaps between them in one large cylindrical container (Patent Document 1). Another proposed method for preventing the hollow fiber membranes from becoming biased is to provide supports with multiple holes at both ends of the cylindrical container in a step prior to fixing the hollow fiber membranes to the cylindrical container with a sealing material, and insert the hollow fiber membranes into the holes to support them (Patent Document 2). [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-117094 [Patent Document 2] Patent No. 03908052 Summary of the Invention [Problem to be solved by the invention]

[0010] However, the hollow fiber membrane module described in Patent Document 1 has a large pressure loss in the second flow path and is premised on applying high pressure to the treatment fluid, so it cannot be applied to hollow fiber membrane modules in which the treatment fluid flows at a low pressure similar to atmospheric pressure.

[0011] In other words, with this method, multiple hollow fiber membrane bundles inserted into small-diameter cylindrical containers are inserted into one large cylindrical container with gaps between them, ensuring a reliable flow path to the small-diameter cylindrical container placed inside the large cylindrical container. Furthermore, since the hollow fiber membranes are packed in the small-diameter cylindrical container at a high packing density, the hollow fiber membranes do not slacken inside the cylindrical container.

[0012] However, when this method is applied to hollow fiber membrane modules for air conditioners, the process fluid not only enters and exits through small through-holes at the top and bottom of a small-diameter cylindrical container, but also flows longitudinally through the gaps between the densely packed hollow fiber membranes. In other words, when considered as a process fluid flow path, the narrow inlet and outlet ports, as well as the narrow and long flow path, result in large pressure losses. Therefore, when using this type of hollow fiber membrane module, the process fluid must be pressurized to flow. However, in the case of air conditioners, for example, the process fluid is ordinary outside air without compression, so pressures above atmospheric pressure cannot be applied. Therefore, the process fluid fed into the hollow fiber membrane module is blocked by high pressure losses, and most of it cannot pass through the hollow fiber membrane module, significantly reducing the processing performance of the hollow fiber membrane module.

[0013] On the other hand, the method for preventing hollow fiber membrane bias described in Patent Document 2 involves inserting both ends of the hollow fiber membrane into a support with multiple holes and then sealing the membrane using centrifugal force. Therefore, when the packing density of the hollow fiber membranes is high, the hollow fiber membranes are evenly arranged and tightly support each other, preventing slack. However, when gaps are provided between the hollow fiber membranes to ensure a flow path to the inner layer of the hollow fiber membrane bundle, the hollow fiber membranes are unable to support each other. Therefore, during the sealing process using centrifugal force, the hollow fiber membrane module must be held horizontally in the longitudinal direction, but the hollow fiber membranes slacken under their own weight. Furthermore, both ends of the hollow fiber membranes are inserted into the holes in the support but are not fixed. Therefore, once slack occurs in the hollow fiber membranes, they slide down through the holes in the support, further increasing the slack. As a result, the hollow fiber membranes are biased to one side of the cylindrical container, except for the area near the support, and a gap is formed between the cylindrical container and the hollow fiber membranes on the other side. This causes most of the treated fluid to pass through the gap, where pressure loss is low, resulting in a decrease in the performance of the hollow fiber membrane module. Furthermore, because the hollow fibers are in a slack, curved state, stress is concentrated at the curved area, creating a high load and reducing the durability of the module during long-term use. [Means for solving the problem]

[0014] The hollow fiber membrane module of the present invention that solves the above-mentioned problems is a hollow fiber membrane module in which the outer periphery of a fiber bundle made up of a plurality of hollow fiber membranes is surrounded by a cover, the fiber bundle made up of a plurality of hollow fiber membranes is a bundle of at least five hollow fiber membranes with connectors attached to both ends, the module is provided with headers made up of two or more membranes that are fitted with the connectors via sealing members, multiple sets of fiber bundles are fitted into the headers made up of two or more membranes, the fiber bundles are arranged with a gap between adjacent fiber bundles, the connectors and the hollow fiber membranes are fixed with a potting material, the multiple sets of fiber bundles fitted into the headers made up of two or more membranes are collectively surrounded by a cover at the outer periphery of the multiple sets of fiber bundles, the cover has an opening of 50% or more on at least one opposing surface, at least a portion of the connector is embedded in the header, and the sealing member is attached to the embedded portion. [Effects of the Invention]

[0015] When the hollow fiber membrane module of the present invention is used, a plurality of fiber bundles each consisting of at least five hollow fiber membranes with connectors attached to both ends are fitted with gaps into a header consisting of two or more membranes in one set, thereby ensuring a flow path to the fiber bundles arranged in the inner layer portion of the hollow fiber membrane module, and thus allowing the treatment fluid to reliably reach the hollow fiber membranes arranged in the inner layer portion of the hollow fiber membrane module while keeping pressure loss low.

[0016] Furthermore, multiple sets of fiber bundles with connectors attached to both ends are prepared in the same shape and fitted to one set of headers. Therefore, unless the fiber bundles and connectors are intentionally manufactured or assembled with different dimensions, there is no risk of some hollow fiber membranes becoming loose within the same hollow fiber membrane module.

[0017] Furthermore, the connector is designed so that at least a portion thereof, including one longitudinal end thereof, is embedded in the header, and a sealing member is disposed at this embedded location. Therefore, if the sealing member is disposed so as to be crushed between the side walls of the embedded portion, variations in the crushing amount of the sealing member do not affect the distance between the connectors described above.

[0018] Furthermore, by using a cover with an opening ratio of 50% or more on the side, pressure loss at the inlet and outlet portions of the flow path can be reduced. Furthermore, between the inlet and outlet, which form the flow path for the treatment fluid, there are no obstacles that prevent the treatment fluid from reaching the hollow fiber membranes, so the treatment fluid that has flowed into the hollow fiber membrane module can be applied to the hollow fiber membranes with high efficiency.

[0019] That is, by using the hollow fiber membrane module of the present invention, a structure is achieved in which the treatment fluid reliably reaches all of the hollow fiber membranes in the hollow fiber membrane module while keeping pressure loss low, so that the treatment performance of the hollow fiber membrane module can be maintained high even when the pressure of the treatment fluid is low. Furthermore, by preventing slack in the hollow fiber membranes, a decrease in durability due to bending can be prevented, allowing the module to be used for a long period of time. [Brief explanation of the drawings]

[0020] [Figure 1] FIG. 1 is a cross-sectional side view of a hollow fiber membrane module of the present invention. [Figure 2] FIG. 2 is a perspective view of a connector constituting the hollow fiber membrane module of Example 1. [Figure 3] FIG. 2 is a perspective view of a header constituting the hollow fiber membrane module of Example 1. [Figure 4] FIG. 2 is a perspective view of a cover constituting the hollow fiber membrane module of Example 1. [Figure 5] FIG. 1 is an explanatory perspective view showing the insertion of hollow fiber membranes into a connector in the production of a hollow fiber membrane module in Example 1. [Figure 6] FIG. 2 is an explanatory cross-sectional view showing a step of treating the ends of a hollow fiber membrane bundle with a sealing material in the production of a hollow fiber membrane module in Example 1. [Figure 7] FIG. 1 is a perspective view showing a state in which the attachment of a connector to only one side has been completed in the production of a hollow fiber membrane module in Example 1. [Figure 8] FIG. 1 is a perspective view of a hollow fiber membrane bundle that constitutes the hollow fiber membrane module of Example 1, with the attachment of connectors completed. [Figure 9]FIG. 2 is an explanatory cross-sectional view showing the step of attaching a hollow fiber membrane bundle to a header in the production of the hollow fiber membrane module of Example 1. [Figure 10] FIG. 1 is a perspective view of a hollow fiber membrane module of Example 1. DETAILED DESCRIPTION OF THE INVENTION

[0021] The present invention will be described with reference to the drawings, taking as an example a hollow fiber membrane module for dehumidification in an air conditioner. Fig. 1 shows a side cross-sectional view of a hollow fiber membrane module 1 according to the present invention. However, preferred embodiments and examples are not limited to this.

[0022] The hollow fiber membrane module 1 of the present invention includes a plurality of hollow fiber membranes 2 arranged at intervals as a hollow fiber membrane bundle 3, enclosed in a rectangular parallelepiped cover 4 having an internal space.

[0023] Here, since the hollow fiber membrane bundles 3 are arranged at intervals as described above, if one hollow fiber membrane bundle 3 is composed of less than five hollow fiber membranes 2, the space efficiency within the hollow fiber membrane module 1 will be poor and the humidification performance per hollow fiber membrane module will be low. Therefore, it is preferable that one hollow fiber membrane bundle 3 is composed of at least five hollow fiber membranes 2 or more.

[0024] Moreover, the hollow fiber membranes 2 enclosed in the cover 4 are preferably arranged in one direction along the longitudinal direction of the hollow fiber membrane module 1.

[0025] Both longitudinal ends of the hollow fiber membrane bundle 3 are inserted into the inner diameter of a cylindrical connector 5, and the gaps between the hollow fiber membranes 2 and the gaps between the hollow fiber membranes 2 and the connector 5 are fixed, i.e., sealed, with a sealant 6, and the cross section of the hollow fiber membrane bundle 3 is opened at the end of the connector 5. Here, as long as the flow path of the treatment fluid that has flowed into the hollow fiber membrane module 1 until it reaches the hollow fiber membranes 2 is not blocked, the connectors 5 fixed to both ends of the same hollow fiber membrane bundle 3 may be connected and integrated with thin supports or the like (not shown) to improve handleability when assembling the hollow fiber membrane module 1.

[0026] Next, the connectors 5 are inserted into a plurality of through-holes 8 provided in a pair of headers 7 arranged in parallel. Here, the connectors 5 do not need to be completely embedded in the through-holes 8; at least a portion of the connectors 5, including one longitudinal end, needs to be inserted into the through-holes 8 to an extent that space is secured for attaching a sealing member 10 (described later) at the embedded portion. Furthermore, to prevent the inserted connectors 5 from slipping out of the through-holes 8, it is preferable to fix them together using a fixing means such as a convex tab and a concave groove (not shown) or an adhesive. Furthermore, when two headers 7 are arranged in parallel, the through-holes 8 are open at the same position, and the two connectors 5 attached to one hollow fiber membrane bundle 3 are arranged on the same straight line. Thus, by appropriately adjusting the distance between the two headers 7, the hollow fiber membranes 2 can be arranged straight without slack. If the size of the hollow fiber membranes 1 is large, two or more miniaturized headers 7 may be used to reduce the load during assembly, for example, a set of four miniaturized headers 7 may be prepared and two of the miniaturized headers 7 may be connected together to form one hollow fiber membrane module 1. In this case, the connecting parts of the miniaturized headers 7 may be integrated by fixing and sealing them with an adhesive or the like.

[0027] A groove 9 is provided in the outer peripheral wall of the connector 5, and an O-ring 10, which is a sealing member, is provided in the recessed portion of the groove, thereby ensuring sealing between the connector 5 and the header 7. As a result, the header 7 has a structure in which the open faces of multiple hollow fiber membrane bundles 3 are bundled together, with one end face of the header 7 functioning as a humidity-conditioning liquid inlet 11 and the other end face of the header 7 functioning as a humidity-conditioning liquid outlet 12. Here, instead of an O-ring, a packing, gasket, or the like may be used as the sealing member, as long as it can be arranged so as to be crushed perpendicular to the outer peripheral wall surface of the connector 5.

[0028] In addition, the connectors are provided with a step portion 13, and when inserted into the through-holes 8 and fixed, the step portion 13 hits the entrance portion of the through-hole, so that all connectors 5 are buried in the header 7 to a constant and identical depth.

[0029] As a result, the distance L1 between the connectors 5 of the multiple hollow fiber membrane bundles 3 assembled to the header 7 within the same hollow fiber membrane module 1 is the same. If the distance L1 between the connectors 5 can all be made the same, there is no need to provide a step 13 in the connectors 5. As a specific example, a step may be provided inside the through-hole 8 to restrict the insertion depth of the connector 5, or an assembly jig that restricts the insertion depth of the connector 5 may be used during the module assembling process. Furthermore, as described above, when the connectors 5 are previously connected and integrated with thin supports or the like during the integration process, there is no need to provide a step or the like in the connectors 5 or through-hole 8 or to use an assembly jig, as long as the distance L1 between the connectors 5 is constant.

[0030] In addition, the plurality of hollow fiber membrane bundles 3 to be assembled to the header 7 may be held vertically with the connectors 5 spaced apart by a distance L1 so as to prevent unnecessary slack in the hollow fiber membranes 2 during the fabrication process, and the connectors 5 and hollow fiber membranes 2 may be fixed with a sealing material 6. In this way, the hollow fiber membranes 2 are stretched straight by gravity and fixed with the sealing material 6, making it possible to easily fabricate a hollow fiber membrane bundle 3 without slack.

[0031] By assembling the plurality of hollow fiber membrane bundles 3 thus produced into the header 7, the state of the hollow fiber membrane bundles 3 at the time of production is reproduced, and the hollow fiber membranes 2 incorporated into the hollow fiber membrane module 1 can be prevented from loosening and bending. As a result, the hollow fiber membranes 2 can be used for a long period of time without decreasing in durability.

[0032] Next, a cover 4 is arranged to surround the outer periphery of the hollow fiber membrane bundle 3 and the pair of headers 7, and is fastened to the headers 7 with bolts (not shown). An outside air inlet 14 and an outside air outlet 15 are provided through a pair of opposing side wall surfaces of the cover 4 as holes for outside air, which is the treatment fluid, to enter and exit the hollow fiber membrane module 1, and are configured to supply outside air to the hollow fiber membranes 2 arranged in the hollow fiber membrane module 1. The humidity-conditioning liquid with a low moisture content that enters through the humidity-conditioning liquid inlet 11 described above adsorbs water vapor contained in the outside air through the outer wall of the hollow fiber membranes 2 as it passes through the inside of the hollow fiber membranes 2, and is discharged from the humidity-conditioning liquid outlet 12 as a humidity-conditioning liquid with an increased moisture content, thereby functioning to dehumidify the outside air.

[0033] Here, for efficient water vapor exchange, it is necessary to expose the entire hollow fiber membrane bundle 3 to outside air, so it is preferable to provide an outside air inlet 14 that opens over 50% or more of the area of ​​one of the opposing surfaces of the cover 4, and an outside air outlet 15 that opens over 50% or more of the area of ​​the surface on the other surface. Furthermore, in order to expose the hollow fiber membranes evenly to outside air, it is more preferable that the outside air inlet 14 and the outside air outlet 15 are evenly arranged with respect to the area of ​​the surface to which they open. Note that in the example of this embodiment, the hollow fiber membrane module 1 is box-shaped, but even if the hollow fiber membrane module 1 is cylindrical, it is sufficient that the outside air inlet 14 and the outside air outlet 15 each open over 50% or more of the opposing surface.

[0034] That is, by opening the wall as large as possible and arranging the outside air inlet 14 and the outside air outlet 15 on either side of the hollow fiber membrane bundle 3, the outside air that enters the hollow fiber membrane module 1 from the outside air inlet 14 is discharged to the outside of the hollow fiber membrane module 1 from the outside air outlet 15 while coming into contact with the entire hollow fiber membrane bundle 3, so that the hollow fiber membranes 2 can be used effectively over their entire length, improving dehumidification performance and keeping pressure loss at the inlet and outlet low.

[0035] However, because the cover 4 also has the function of fixing the header 7 and maintaining the shape of the hollow fiber membrane module 1, increasing the opening area of ​​the outside air inlet 14 and the outside air outlet 15 may result in insufficient rigidity of the cover 4. In this case, by dividing the opening on each side into multiple pieces and combining them, the opening will have some wall surface of the cover 4 remaining, and the remaining wall surface will function as a rib, thereby achieving both an increase in the opening area and rigidity of the cover 4.

[0036] Furthermore, if the cover 4 is not one piece but is made of a divided structure, it is preferable to apply a sealant to the joints so that the outside air that enters through the outside air inlet 14 is discharged from the outside air outlet 15 without leaking from the divided parts.

[0037] Furthermore, when the pressure of the treatment fluid flowing into the hollow fiber membrane module 1 is approximately atmospheric pressure, in order to ensure a sufficient distance between the hollow fiber membranes 2 forming the flow paths and reduce pressure loss, it is preferable to adjust the packing amount of the hollow fiber membranes 2 so that the relationship (B × C) / A < 0.30 is satisfied, where A is the area inside the inner wall of the cover 4 in a cross section perpendicular to the longitudinal direction of the hollow fiber membranes 2, B is the area inside the outer diameter of the hollow fiber membranes 2, and C is the number of hollow fiber membranes. Furthermore, if it is desired to increase the distance between the hollow fiber membranes 2 forming the flow paths to a level that can be distinguished visually in order to further reduce pressure loss, it is more preferable to adjust the packing amount of the hollow fiber membranes 2 so that the relationship (B × C) / A < 0.15 is satisfied.

[0038] The materials that can be used for the connector 5, header 7, and cover 4 that constitute the hollow fiber membrane module 1 of the present invention may be any material, such as metal or resin. However, it is preferable to use a resin that is inexpensive, highly processable, and can be mass-produced by injection molding, and polyacetal, polycarbonate, polypropylene, etc. are more preferable.

[0039] If it is desired to make the cover 4 thin while maintaining high rigidity, it is preferable to use a metal, such as stainless steel or an aluminum alloy.

[0040] The material of the hollow fiber membrane 2 is not particularly limited, and may be selected appropriately from polysulfone, polyethersulfone, polyimide, polyolefin, etc. depending on the conditions of use.

[0041] The use of the hollow fiber membrane module 1 of the present invention is not particularly limited, and it can be used as a humidifying module for moisturizing the ion exchange membrane of a fuel cell, a humidifying and dehumidifying module inside an air conditioner, or a heat exchanger module.

[0042] Furthermore, the hollow fiber membrane module 1 of the present invention is not limited to being used alone, but can also be used as a module for separation membrane applications by combining multiple modules to remove particles contained in liquids or gases, or to filter, concentrate, or purify solutions or substances dissolved in solutions. [Example]

[0043] The present invention will be specifically described below with reference to examples. Note that, although one embodiment of the hollow fiber membrane module of the present invention will be described below, the content of the present invention is not limited to these. [Example 1] Using polysulfone as the material, 36 connectors 5 with the shape shown in Figure 2 and two headers 7 with the shape shown in Figure 3 were produced by injection molding and cutting. In addition, using stainless steel as the material, two covers 4 with the shape shown in Figure 4 were produced.

[0044] The dimensions of each part of the connector 5 were D1=13 mm, D2=5 mm, D3=9 mm, D4=11 mm, L1=18 mm, L2=15 mm, and L3=2.5 mm.

[0045] The dimensions of each part of the header 7 were L4 = 55 mm, L5 = 100 mm, L6 = 18 mm, L7 = 3 mm, L8 = 3 mm, L9 = 3 mm, L10 = 15 mm, L11 = 15 mm, and D5 = 11 mm.

[0046] The dimensions of each part of the cover 4 were L12=29.5 mm, L13=104 mm, L14=336 mm, L15=95 mm, L16=90 mm, and T1=2 mm.

[0047] A hollow fiber membrane bundle 3 was produced using the above connectors 5. First, as shown in Fig. 5, two connectors 5 were arranged symmetrically and on the same line, and with the distance L17 between the opposing faces maintained at 300 mm, they were fixed using a fixing jig (not shown) so that their axes were aligned vertically.

[0048] Ten hollow fiber membranes 2 made of polysulfone, each having an outer diameter of 1000 μm and an inner diameter of 720 μm and cut to a length of 450 mm, were then inserted together into the holes in the connector 5. At this time, the hollow fiber membranes 2 were fixed with a jig (not shown) so that the distance L18 between the lower end of the hollow fiber membrane bundle 3 and the lower end of the connector 5 was 10 mm. Thereafter, a urethane-based sealant (manufactured by Sanyu Rec Co., Ltd., model number: SA8215) was applied to the lower end of the hollow fiber membrane bundle 3, and a sealing treatment was performed to fill the inner diameter portion of the hollow fiber membranes 2.

[0049] Next, with reference to FIGS. 6(a) to 6(d), the procedure for treating the ends of the hollow fiber membrane bundle 3 with the sealing material 6 and opening the inner diameter portions of the hollow fiber membranes 2 will be described.

[0050] First, as shown in Fig. 6(a), a cylindrical cap-shaped sealing jig 16 was attached in close contact with the tip of the connector 5, and the injection of the same sealing material 6 as described above was started through the bottom hole 17. Then, as shown in Fig. 6(b), the injection was stopped when the injected sealing material 6 reached the upper end of the connector 5, and a cap 18 was attached. Next, after the sealing material 6 solidified, as shown in Fig. 6(c), the sealing jig 16 was removed from the connector 5, and the hollow fiber membranes 2 and sealing material 6 protruding from the lower end of the connector 5 were cut as close to the lower end of the connector 5 as possible, as shown in Fig. 6(d), thereby opening the inner diameter of the hollow fiber membranes 2.

[0051] The hollow fiber membranes 2 arranged below the hollow fiber membrane bundle 3 were now opened, and the hollow fiber membrane bundle 3 was turned upside down. Then, as shown in FIG. 7, the hollow fiber membranes 2 were cut so that the distance L19 between the lower end of the hollow fiber membrane bundle 3 and the lower end of the connector 5 was 10 mm. After straightening the hollow fiber membranes 2 to eliminate any slack, the sealing material 6 was applied to the lower end of the hollow fiber membrane bundle 3 to seal the hollow fiber membranes. The same procedures as those used to process the end of the upper hollow fiber membrane bundle 3 were then carried out, from the installation of the sealing jig 16 (state shown in FIG. 6(a)) to the opening of the inner diameter of the hollow fiber membranes 2 (state shown in FIG. 6(d)). By repeating the above procedures, a total of 18 hollow fiber membrane bundles 3 equipped with connectors 5 were produced, as shown in FIG. 8.

[0052] Next, as shown in the cross-sectional view of Figure 9, an O-ring 10 (standard: S9, material: NBR) was attached to the groove 9 of the connector 5, and the connector 5 was inserted into the hole portion of the header 7 arranged in parallel. Then, when the step portion 13 of the connector 5 came into contact with the header 7, the insertion operation of the connector 5 was stopped, and the position of the header 7 was adjusted so that the two connectors 5 were in the same straight line and the distance L17 between the opposing surfaces was 300 mm, and connectors 5 with O-rings 10 attached were inserted into all the remaining holes in the same manner as above.

[0053] Next, to prevent the connector 5 from coming loose, the same sealant 6 as described above was poured into the recess of the header 7 and allowed to solidify. The sealant 6 was poured to a liquid depth L20 of 2.5 mm, while the depth L7 of the recess of the header 7 was 3 mm.

[0054] Finally, as shown in Fig. 10, while the header 7 was maintained in the position described above, the two covers 4 were fastened and fixed to the upper and lower headers 7 with bolts (not shown), thereby fixing the positions of the upper and lower headers 7 and completing the hollow fiber membrane module 1. The same sealant 6 as above was applied to the joints of the cover 4 to seal any gaps.

[0055] The hollow fiber membrane module 1 fabricated as described above was visually inspected to check the degree of slack in the hollow fiber membranes 2 and the gaps between the hollow fiber membrane bundles 3. The results showed that the hollow fiber membranes 2 were not curved and showed no slack that would cause stress concentration. Furthermore, the hollow fiber membrane bundles 3 were slightly bulged at the center compared to the ends, and the spacing between the hollow fiber membrane bundles 3 was narrower at the center than at the base of the bundle, but the spacing was still large enough to be clearly visible. In other words, visually visible flow paths were formed between the hollow fiber membrane bundles 3, and it was clear that even a treatment fluid pumped into the hollow fiber membrane module at atmospheric pressure could reach all of the hollow fiber membranes 2 and easily pass through to the outside of the hollow fiber membrane module 1 without being obstructed by pressure loss. [Explanation of symbols]

[0056] 1. Hollow fiber membrane module 2. Hollow fiber membrane 3 Hollow fiber membrane bundle 4 Cover 5 Connectors 6. Encapsulating material 7. Header 8 through holes 9 grooves 10 O-rings 11 Humidity control liquid inlet 12 Humidity control liquid outlet 13 Step 14 Fresh air intake 15. Outside air outlet 16 Sealing jig 17 Bottom hole 18 Cap

Claims

1. A hollow fiber membrane module in which an outer periphery of a fiber bundle formed by bundling a plurality of hollow fiber membranes is surrounded by a cover, and the fiber bundle formed by bundling a plurality of hollow fiber membranes is formed by bundling at least five hollow fiber membranes each having a connector attached to both ends thereof, a set of two or more headers fitted to the connector via a seal member; A plurality of sets of the yarn bundles are fitted to the headers, each set consisting of two or more bundles, The yarn bundles are arranged with a gap between adjacent yarn bundles, the connector and the hollow fiber membrane are fixed by a potting material, The plurality of sets of yarn bundles fitted into the headers, each consisting of two or more headers, are collectively surrounded by a cover at their outer peripheries, the cover is open by 50% or more on at least one pair of opposing surfaces, At least a portion of the connector including one end in the longitudinal direction is embedded in the header, The hollow fiber membrane module has the sealing member attached to the buried portion.

2. 2. The hollow fiber membrane module according to claim 1, wherein, in a cross section perpendicular to the longitudinal direction of the hollow fiber membranes, the area of ​​the portion inside the inner wall of the cover is A, the area inside the outer diameter of the hollow fiber membrane is B, and the number of the hollow fiber membranes is C, the relationship (B × C) / A < 0.30 is satisfied.

3. 3. The hollow fiber membrane module according to claim 1 or 2, which is used for dehumidification or humidification.

4. The hollow fiber membrane module according to claim 3, which is used for an air conditioner.

5. 3. The hollow fiber membrane module according to claim 1 or 2, wherein a plurality of the hollow fiber membrane modules are used in combination as separation membranes.

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