Hollow fiber membrane module

Abstract

To provide a hollow fiber membrane module which has low pressure loss when a flow rate increases and is excellent in humidification efficiency.SOLUTION: A hollow fiber membrane module has a hollow fiber membrane bundle 10 in a cylindrical module case 9. The hollow fiber membrane module has only outlets whose diameter is 5 mm or more and less than 10 mm in a region A, has only inlets whose diameter is 10 mm or more and 30 mm or less in a region B, has only outlets whose diameter is 5 mm or more and 10 mm or less in a region C, and has only outlets whose diameter is 10 mm or more and 30 mm or less in a region D. A center (output / large) is arranged at the position of 180±30° in a circumferential direction of the module case from a center (input / large), a center (input / small) is arranged at the position of 180±30°in a circumferential direction of the module case from the center (input / large), and a center (output / small) is arranged at the position of 180±30°in a circumferential direction of the module case from the center (output / large).SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] This invention relates to a hollow fiber membrane module that enables efficient moisture exchange. [Background technology]

[0002] Hollow fiber membrane modules are used in a variety of applications because they have a large membrane area and allow for miniaturization of the device. An example of such a hollow fiber membrane module is shown in Figure 4. In Figure 4, there is a hollow fiber membrane bundle 10 consisting of multiple hollow fiber membranes 1, a module case 9 as shown in Figure 4 that houses the hollow fiber membrane bundle 10, a sealing and fixing part consisting of a potting material 3 that adhesively seals both ends of the hollow fiber membrane bundle 10, hollow fiber membrane openings 2 in which both end faces of the hollow fiber membranes 1 open to the partition resin, and the module case 9 has inlets and outlets 5 and 6 on its side surface for fluid conduction.

[0003] Here, the side of the module case refers to the surface facing the outer portion of the hollow fiber membrane it contains. A module case is a structure that has hollow fiber openings formed by potting material at both ends, and can separate the processing fluid from the fluid to be processed by sealing material such as an O-ring.

[0004] In this example, the system is configured with a housing consisting of a port section 12 on the outside of the hollow fiber membrane, which has a first fluid inlet 13 on the inside of the hollow fiber membrane for the fluid to be processed and a second fluid inlet 15 on the outside of the hollow fiber membrane, a first fluid outlet 14 on the inside of the hollow fiber membrane, and a second fluid outlet 16 on the outside of the hollow fiber membrane, respectively, and a header section 11 on the inside of the hollow fiber membrane, and is equipped with elastic O-rings 21 for separating and sealing the fluids to be processed and the fluid to be processed, respectively. It is also possible to use a housing 22 that has ports for inflow and outflow fluids and nozzles for joining the module case itself.

[0005] In such hollow fiber membrane modules, measures are taken to improve the processing capacity of the humidifier, such as increasing the membrane area or reducing the space required for the processor to make it more compact. In such cases, the processing flow rate per unit hollow fiber membrane decreases for the fluid being processed inside the hollow fiber membrane. Therefore, various measures have been proposed to increase the humidification efficiency of humidifying membrane modules, such as conducting a large amount of gas to the outside of the hollow fiber membrane.

[0006] For example, Patent Document 1 describes an example of responding to flow rate changes by switching the airflow path, and Patent Document 2 describes an example of improving exchange efficiency by arranging circular holes at both ends of the case of a circular module to make the flow velocity uniform. Furthermore, Patent Documents 3 and 4 show examples of achieving flow uniformity by gradually decreasing the opening area from the inlet. In addition, Patent Document 5 describes an example of changing the flow velocity by switching the flow path of the conductive gas.

[0007] However, with these module shapes, if a large flow rate of processed or processed gas is passed on the outside of the hollow fibers, the opening area may not be sufficient, leading to a significant increase in pressure loss within the module. Conversely, if the opening diameter is excessive, there is a risk of damage to the hollow fiber membrane due to the impact of the flowing fluid.

[0008] In addition, there are examples of attempts to improve humidity exchange efficiency by providing circular outlets located on opposite sides of both ends (Patent Document 6), but at high airflow rates, compaction of the hollow fiber bundle occurs, making it unavoidable that pressure loss will increase. [Prior art documents] [Patent Documents]

[0009] [Patent Document 1] Japanese Patent Publication No. 2008-041335 [Patent Document 2] Japanese Patent Publication No. 2005-224719 [Patent Document 3] Japanese Patent Publication No. 2007-147139 [Patent Document 4] Japanese Patent Publication No. 2005-156039 [Patent Document 5] Japanese Patent Publication No. 2008-027674 [Patent Document 6] Japanese Patent Publication No. 2012-130864 [Overview of the project] [Problems that the invention aims to solve]

[0010] As described above, in order to improve exchange efficiency, if a large flow rate of the gas to be processed or the gas to be processed is passed on the outside of the hollow fibers, there is a risk of damage to the hollow fiber bundle due to the impact of the conductive gas, and an increase in pressure loss in the module, which could lead to an increase in the equipment load for processing and a decrease in the overall efficiency of the device. Therefore, there was a need for a hollow fiber membrane module design that would reduce the increase in conductive pressure loss while maintaining exchange efficiency.

[0011] As a means of solving the above problems, the present invention is characterized by appropriately securing the area of ​​the opening in the module case and securing a fluid flow path on the opposite side of the axis center of the main opening, thereby setting the position of the fluid inlet and outlet.

[0012] This invention provides a hollow fiber membrane module that reduces pressure loss when the flow rate increases by ensuring sufficient opening area in the module, and further reduces pressure loss in the outer portion of the hollow fiber by allowing some fluid to be conducted at positions opposite the axial center and longitudinal center of the opening center of the fluid inlet and outlet, thereby suppressing damage to the hollow fiber bundle. [Means for solving the problem]

[0013] The present invention, which solves the above-mentioned problems, is as follows: A hollow fiber membrane module having a bundle of hollow fiber membranes inside a cylindrical module case, At both ends of the hollow fiber membrane module, the hollow fiber membrane is open, and the gaps between the hollow fiber membranes and between the hollow fiber membrane and the module case are sealed with potting material. The module case has a region A that is half of the module case length from one end face of the module case and within 150° in the circumferential direction of the module case, and a region B within 210° at a position opposite to the region A in the circumferential direction. The module case has a region C that is half of the module case length from the other end face of the module case and within 150° in the circumferential direction of the module case, and a region D within 210° at a position opposite to the region C in the circumferential direction. Region A has only inlet ports (hereinafter referred to as small inlet ports) with a diameter of 5 mm or more and less than 10 mm. All the small inlet ports in region A are grouped together as a group (inlet / small), with the center of the group (inlet / small) being the center (inlet / small). Region B has inlet ports (hereinafter referred to as large inlet ports) with a diameter of 10 mm or more and 30 mm or less. All the large inlet ports in region B are grouped together as a group (inlet / large), with the center of the group (inlet / large) being the center (inlet / large). Region C has only outlet ports (hereinafter referred to as small outlet ports) with a diameter of 5 mm or more and less than 10 mm. All the small outlet ports in region C are grouped together as a group (outlet / small), with the center of the group (outlet / small) being the center (outlet / small). Region D has outlet ports (hereinafter referred to as large outlet ports) with a diameter of 10 mm or more and 30 mm or less. When all the large outlet ports in region D are grouped together as a group (outlet / large) and the center of the group (outlet / large) is the center (outlet / large), there may be ports with a diameter of less than 5 mm in regions A and C as well. The center (outlet / large) is arranged at a position 180 ± 30° in the circumferential direction of the module case from the center (inlet / large). The center (inlet / small) is arranged at a position 180 ± 30° in the circumferential direction of the module case from the center (inlet / large). The center (outlet / small) is arranged at a position 180 ± 30° in the circumferential direction of the module case from the center (outlet / large). Hollow fiber membrane module.

Advantages of the Invention

[0014] The hollow fiber membrane module of the present invention reduces the pressure loss during flow rate increase by ensuring the opening area of the fluid inlet and outlet in the module case, arranges the position of the opening center of the fluid inlet and outlet on the opposite side with respect to the axial center and the center in the length direction, and further opens a part of the fluid so that it can conduct through the position opposite to the axial center and the center in the length direction of the opening center of the fluid inlet and outlet, thereby providing a hollow fiber membrane module capable of improving the humidification efficiency.

Brief Description of the Drawings

[0015] [Figure 1] It is a cross-sectional view showing an example in which the hollow fiber membrane module of the present invention is incorporated into a housing. [Figure 2] It is a perspective view showing an example of the hollow fiber membrane module case of the present invention. [Figure 3] It is a developed configuration diagram of the circular opening portion arranged in the hollow fiber membrane circular module case of the present invention. The + marks and × marks in the figure are the opening centers of their respective opening groups. [Figure 4] It is a cross-sectional view showing an example in which a conventional hollow fiber membrane module is incorporated into a housing. [Figure 5] It is a perspective view showing an example of a conventional hollow fiber membrane module case. [Figure 6] It is a developed configuration diagram of the circular opening portion arranged in the conventional hollow fiber membrane circular module case. The ┼ marks in the figure are the opening centers of their respective opening groups. [Figure 7] It is a diagram showing a method for calculating the opening center in a general opening group. [[ID=二十七]] [Figure 8] It is a coordinate diagram for calculating the opening center of the opening portion of the present invention.

Embodiments for Carrying Out the Invention

[0016] The hollow fiber membrane module of the present invention is a hollow fiber membrane module having a bundle of hollow fiber membranes inside a cylindrical module case, wherein the hollow fiber membranes are open at both ends of the hollow fiber membrane module, the gaps between the hollow fiber membranes and the gaps between the hollow fiber membranes and the module case are sealed with a potting material, and the module case has a region A extending from one end face of the module case to half the length of the module case and within 150° in the circumferential direction of the module case, and a region A extending 210° or less at opposite positions in the circumferential direction of region A. The module case has an internal region B, a region C extending from the other end face of the module case to half the length of the module case and within 150° in the circumferential direction of the module case, and a region D extending within 210° at an opposing position in the circumferential direction of region C, and region A has only inlets with a diameter of 5 mm or more and less than 10 mm (hereinafter referred to as small inlets), all small inlets in region A are collectively called group (inlet / small), the center of group (inlet / small) is called center (inlet / small), and region B has inlets with a diameter of 10 mm or more and 30 mm or less (hereinafter referred to as large inlets) Region B has all large inlets except those with a diameter of less than 5 mm, and the center of this group (inlet / large) is designated as the center (inlet / large). Region C has only outlets with a diameter of 5 mm or more and less than 10 mm (hereinafter referred to as small outlets), and all small outlets in Region C have all small outlets, and the center of this group (outlet / small) is designated as the center (outlet / small). Region D has outlets with a diameter of 10 mm or more and 30 mm or less (hereinafter referred to as large outlets), and all large outlets in Region D have all large outlets, and the center of this group (outlet / large) is designated as the center (outlet / small). This is a hollow fiber membrane module in which, when the center (protruding / large) is defined, there may be openings with a diameter of less than 5 mm in regions A and C, the center (protruding / large) is positioned at a position of 180 ± 30° from the center (inlet / large) in the circumferential direction of the module case, the center (inlet / small) is positioned at a position of 180 ± 30° from the center (inlet / large) in the circumferential direction of the module case, and the center (protruding / small) is positioned at a position of 180 ± 30° from the center (protruding / large) in the circumferential direction of the module case.

[0017] The hollow fiber membrane module of the present invention will be described in detail below with reference to the figures.

[0018] Figure 1 is a cross-sectional view showing an example in which the hollow fiber membrane module according to the present invention is incorporated into the housing 22, as described above.

[0019] The present invention has a hollow fiber membrane bundle 10 made of hollow fiber membranes 1 inside a cylindrical module case 9, and furthermore, the hollow fiber membranes 1 open at both ends of the hollow fiber membrane module, and the gaps between the hollow fiber membranes 1 and between the hollow fiber membranes 1 and the module case 9 are sealed with potting material 3. In other words, a bundle of hollow fiber membranes 1 is inserted into a module case 9 which has openings such as a large inlet 5, a large outlet 6, a small inlet 7, and a small outlet 8 as shown in Figures 2 and 3, and both ends of the module case 9 are sealed with potting material 3 by a known method, and the ends are cut to form hollow fiber membrane openings 2. This module case 9 is fixed with a support 21 together with a header section 11 and a port section 12, which have ports for a first fluid inlet 13, a first fluid outlet 14, a second fluid inlet 15, and a second fluid outlet 16 on the inside and outside of the hollow fiber membrane, respectively, and an O-ring 23 for sealing, to constitute a hollow fiber membrane module.

[0020] Here, the module case 9 ensures an appropriate area for the inlet and outlet openings, and sets the position of the center of the fluid inlet and outlet openings. By ensuring an appropriate area for the inlet and outlet openings of the module case 9, the increase in pressure loss when the flow rate increases is reduced, and furthermore, by positioning the center of the fluid inlet and outlet openings on the opposite side of the axial center and the longitudinal center, the humidification efficiency is improved.

[0021] Furthermore, while maximizing the area of ​​the outlet and inlet openings of the module case is expected to suppress conductivity resistance and reduce pressure loss, the arrangement of the outlet and inlet openings can cause fluid short paths, creating dead spaces and reducing humidification efficiency. Therefore, the area of ​​the large inlet and outlet module cases viewed from the inside is preferably 5.0-30.0% of the internal surface area of ​​half the total length of the module case, and the area of ​​the small inlet and outlet module cases viewed from the inside is preferably 1.0-3.0% of the internal surface area of ​​half the total length of the module case. The internal surface area of ​​half the total length of the module case refers to the internal surface area of ​​the module case in a portion of the module case that is half the total length of the module case. This module case has a zone in the center that separates the fluid inlet and outlet on the outside of the hollow fiber membrane. However, it is also possible to vary the opening area on the fluid inlet and outlet sides, and this can be determined appropriately for efficient fluid exchange. Even in this case, it is preferable to set it as described above. In the present invention, the module case has a region A extending from one end face of the module case to half the length of the module case and within 150° in the circumferential direction of the module case, and a region B extending from the opposite circumferential position of region A to within 210°, and a region C extending from the other end face of the module case to half the length of the module case and within 150° in the circumferential direction of the module case, and a region D extending from the opposite circumferential position of region C to within 210°. Region A has only inlets with a diameter of less than 10 mm (hereinafter referred to as "small inlets"), and all small inlets in Region A are collectively called the group (inlet / small), with the center of the group (inlet / small) being designated as the center (inlet / small). Region B has inlets with a diameter of 10 mm or more and 30 mm or less (hereinafter referred to as "large inlets"), and all large inlets in Region B are collectively called the group (inlet / large), with the center of the group (inlet / large) being designated as the center (inlet / large). Region C has only outlets with a diameter of less than 10 mm (hereinafter referred to as "small outlets"), and all small outlets in Region C are collectively called the group (outlet / small), with the center of the group (outlet / small) being designated as the center (outlet / small). Region D has outlets with a diameter of 10 mm or more and 30 mm or less (hereinafter referred to as "large outlets"), and all large outlets in Region D are collectively called the group (outlet / large), with the center of the group (outlet / large) being designated as the center (outlet / large). In this case, it is preferable that the diameter in Regions A and C is 5 mm or more. Furthermore, in determining the groups and centers within regions A, B, C, and D in this invention, inlets with a diameter of less than 5 mm are excluded from consideration. To explain this in detail with reference to the drawings, in Figure 1, the small inlets 7 are arranged on the side where the second fluid inlet 15 is located, and the large inlet 5 is arranged on the opposite side. Also, the small outlet 8 is arranged on the side where the second fluid outlet 16 is located, and the large outlet 6 is arranged on the opposite side, forming a module case. Here, in this invention, all the large inlets within region B are collectively defined as a group (inlet / large), so the area of ​​the group (inlet / large) as seen from inside the module case means the sum of the areas of all the large inlets as seen from inside the module case. The same applies to the area of ​​the group (outlet / large) as seen from inside the module case, the area of ​​the group (inlet / small) as seen from inside the module case, and the area of ​​the group (outlet / large) as seen from inside the module case.

[0022] A large inlet refers to an inlet with a diameter of 10 mm or more and 30 mm or less, a small inlet refers to an outlet with a diameter of less than 10 mm, a large outlet refers to an outlet with a diameter of 10 mm or more and 30 mm or less, and a small outlet refers to an outlet with a diameter of less than 10 mm. Here, the shape of the inlet and outlet is not particularly limited and includes circles, ellipses, etc. In the case of shapes other than circles, the diameter of the inlet and outlet can be determined by replacing them with the hydraulic diameter DH, which is expressed by the following formula.

[0023] Hydraulic diameter (DH) = 4 × area of ​​opening / perimeter of opening.

[0024] In this invention, when all the large inlets in region B are collectively called group (inlet / large) and the center of group (inlet / large) is called center (inlet / large), all the large outlets in region D are collectively called group (outlet / large) and the center of group (outlet / large) is called center (outlet / large), all the small inlets in region A are collectively called group (inlet / small) and the center of group (inlet / small) is called center (inlet / small), and all the small outlets in region C are collectively called group (outlet / small) and the center of group (outlet / small) is called center (outlet / small), then center (outlet / large) is positioned at a position 180±30° from center (inlet / large) in the circumferential direction of the module case, center (inlet / small) is positioned at a position 180±30° from center (inlet / large) in the circumferential direction of the module case, and center (outlet / small) is positioned at a position 180±30° from center (outlet / large) in the circumferential direction of the module case. In this way, the gas flow can be directed from the outer circumference of the large inlet, through the radial center of the hollow fiber membrane bundle, and to the other large outlet. Furthermore, by placing the small inlet and small outlet on opposite sides of the circumference of the large inlet and large outlet, respectively, short paths for the fluid are eliminated, allowing for effective use of the entire hollow fiber membrane bundle, improving exchange efficiency and reducing pressure loss. More preferably, by positioning them at 180±15°, it becomes possible to ensure that the fluid passes through the center of the hollow fiber membrane bundle, further improving exchange efficiency.

[0025] Here, the group (inlet / large) refers to all the large inlets. Therefore, the center (inlet / large), which is the center of the group (inlet / large), refers to the centroid obtained using all the large inlets. As shown in Figure 7, if the centers of the large inlets (inlet / large) with opening areas S1, S2, S3, ... are located on the module case at coordinates x1y1, x2y2, x3y3, ..., the coordinates xGyG of the center (inlet / large), which is the center of the group (inlet / large), are expressed by the following equation. xG=(s1×x1+s2×x2+s3×x3+...) / (s1+s2+s3+...) yG=(s1×y1+s2×y2+s3×y3+...) / (s1+s2+s3+...) Therefore, when an opening is made in the module case as shown in Figure 3, the centers (inlet / outlet) of each will be the points indicated by the "+" sign.

[0026] When determining the center (inlet / large) of the group (inlet / large), the coordinate base point can be set anywhere, but to simplify the specification, as shown in Figure 8, the point 1L13, the center of the outlet large at one end, is used as the starting point on the circumference.

[0027] The center of the group (inlet / large) is the centroid obtained using all inlet large containers except those with a diameter of less than 5 mm. To find this, it is necessary to determine the center of each individual inlet large container. Here, the center of each individual inlet large container is the centroid of that individual inlet large container. Therefore, if the inlet large container is a circle, the center of the circle becomes the center of the inlet large container. If the shape of the inlet large container is not circular, and it is a regular shape such as an oval or rectangle, the center can be found by calculating the centroid according to the formula for finding the centroid. If the shape is irregular, the shape can be cut into small parallel strips, and the centroid of each strip can be calculated to find the center. The centroid of the irregularly shaped inlet large container can then be found by calculating the centroid from the coordinates of the centers of all the strips.

[0028] Up to this point, we have described how to find the large inlet, the large group (inlet), and the large center (inlet). The same method applies to the large center (outlet), the small center (inlet), and the small center (outlet).

[0029] Furthermore, the statement that the center (outgoing / large) is positioned 180±30° from the center (ingoing / large) in the circumferential direction of the module case means that the center (outgoing / large) is positioned at a location rotated 180±30° from the center (ingoing / large) in the circumferential direction of the module case. This means that the center (outgoing / large) is positioned at a location rotated 180±30° around the longitudinal direction of the cylindrical module case. The same applies to the points that the center (ingoing / small) is positioned 180±30° from the center (ingoing / large) in the circumferential direction of the module case, and the points that the center (outgoing / small) is positioned 180±30° from the center (outgoing / large) in the circumferential direction of the module case.

[0030] In this invention, in order to form such a flow, it is preferable that the enclosed hollow fiber membrane bundle be arranged in close contact with the module case. That is, it is preferable that the hollow fiber membrane bundle inserted when creating the hollow fiber membrane module be inscribed within the module case, and that the inscribed portion be arranged so that the second fluid conducting outside the hollow fiber membrane does not short-circuit the outer circumference. However, even if some short-circuiting occurs during actual use, it is permissible as long as it is within a range that can form the counterflow which is the objective of this invention. The "close contact" state is determined by observing the arrangement of the hollow fiber membrane bundle from the opening of the hollow fiber membrane module. In order to arrange the hollow fiber membrane bundle in close contact with the module case, it is also an effective means to fix the hollow fiber membrane bundle with a protective net as shown in Figure 1, 4.

[0031] In the present invention, it is preferable that the large inlet is located at least 15 mm from one end face of the module case, and further located in a region no more than 75% of half the length of the module case from one end face; the large outlet is located at least 15 mm from the other end face of the module case, and further located in a region no more than 75% of half the length of the module case from the other end face; the small inlet is located at least 15 mm from one end face of the module case, and further located in a region no more than 35% of half the length of the module case from one end face; and the small outlet is located at least 15 mm from the other end face of the module case, and further located in a region no more than 35% of half the length of the module case from the other end face. To explain this in more detail, the positions of the large inlet, large outlet, small inlet, and small outlet are set to be at least 15 mm from their respective end faces, taking into consideration the thickness of the potting material. Furthermore, regarding the position of the large inlet within 75% of half the module case length from one end face of the module case, since half the module case length is 50% of the module case, the position of the large inlet within 75% of half the module case length from one end face of the module case means that the large inlet is positioned at 37.5% (= 50% × 75%) of the total length of the module case from one end face. The same applies to the large outlet, small inlet, and small outlet. Note that the position of the large inlet within 15 mm or more from one end face of the module case, and within 75% of half the module case length from one end face of the module case, means that if there are multiple large inlets, at least one large inlet is located in this area, and it is particularly preferable that all large inlets are located in this area. The same applies to the large outlet, small inlet, and small outlet.In this way, the entire length of the bundle is utilized, from the bundle near the end face of the module case, where most of the potting material is located, to the bundle near the outlet on the other side. At the same time, the second fluid is prevented from short-circuiting the gap between the module case and the hollow fiber bundle near the center of the hollow fiber bundle in the length direction, and the water vapor exchange efficiency is improved by maintaining the opening area.

[0032] In the present invention, it is preferable to place a protective net between the module case and the hollow fiber membrane bundle. Here, the protective net is a net-like material composed of fibers. The material of the fibers constituting the protective net is preferably highly rigid so as to mitigate the impact when the second fluid is introduced and exited on the outside of the hollow fiber membrane, and further preferably has a melting point or softening point so that the tips of the fibers constituting the protective net can be heat-processed. Furthermore, in order to mechanically suppress the deformation of the hollow fiber membrane, the fiber diameter constituting the protective net is preferably 100 to 500 μm, and the inter-fiber gap distance constituting the protective net is preferably 200 to 1,000 μm. At the same time, in order to ensure these configurations and to allow for easy setting of fiber embedding, the structure of the protective net is preferably plain weave.

[0033] Mesh sheets are also a preferred material for protective nets. Furthermore, polyethylene terephthalate resins, polysulfone resins, nylon resins, fluorine-containing resins, PPS resins, AS resins, ABS resins, etc., can be appropriately selected as the material for the protective net depending on the intended use of the module.

[0034] In this invention, it is preferable that the ratio of the sum of the volumes based on the outer diameter of the hollow fiber membranes to 100% of the internal volume of the module case (hereinafter referred to as the packing rate) is 50% or more and 65% or less. When the packing rate is 50% or more, the gap between the hollow fiber membrane bundle and the module case becomes smaller, making it less likely for the second fluid to short-circuit, which leads to an improvement in humidification efficiency. Furthermore, when the packing rate is 65% or less, the operability when inserting the hollow fiber membrane bundle into the module case is improved and the hollow fiber membrane bundle is less likely to be damaged. Here, the sum of the volumes based on the outer diameter of the hollow fiber membranes means the value obtained by multiplying the cross-sectional area using the outer diameter of the hollow fiber membrane by the length of the bundle to find the volume, and then summing the volumes of all the hollow fiber membranes.

[0035] Furthermore, the applications of the hollow fiber membrane module of the present invention are not particularly limited, and it can also be used for humidification and dehumidification applications that take advantage of its water vapor permeability.

[0036] In this case, when the hollow fiber membrane module of the present invention is used for humidification purposes, it is preferable to use a fuel cell humidifier in which the center (inlet / large) of the hollow fiber membrane module is positioned 180±30° opposite the fluid inlet of the housing having a port portion on the circumference.

[0037] The present invention provides a method for recovering water vapor using the hollow fiber membrane module, which involves either a counterflow or crossflow of the first and second fluids. This technology combines both methods. Specifically, by setting an arrangement that allows for both a counterflow, which offers high water vapor exchange efficiency, and a crossflow, which reduces pressure loss, an ideal hollow fiber membrane module can be obtained. Therefore, the technology of this invention can be effective in stationary fuel cells and fuel cell vehicles that process large volumes of fluid. In other words, the stationary fuel cell of this invention is a stationary fuel cell that includes the hollow fiber membrane module of this invention, and the fuel cell vehicle of this invention is a fuel cell vehicle that includes the hollow fiber membrane module of this invention. [Examples]

[0038] (1) How to find the center of various groups (e.g., group (entry / large)) As shown in Figures 3 and 6, the centers of the groups at the inlet and outlet were determined by representing them on a coordinate system as shown in Figure 8, as described above.

[0039] (2) Opening ratio of the module case (the ratio of the area of ​​the module case as seen from the inside to the total internal surface area of ​​half the length of the module case) The inner surface of a cylindrical or rectangular module case is unfolded onto a plane, and the ratio of the total area of ​​the groups (in / large), (in / small), (out / large), and (out / small) placed on it to the unfolded case area (the ratio of the area of ​​the group (in / large) as seen from inside the module case, the area of ​​the group (out / large) as seen from inside the module case, the area of ​​the group (in / small) as seen from inside the module case, and the area of ​​the group (out / small) as seen from inside the module case, to the inner surface area of ​​half the length of the entire module case) was defined as the opening ratio.

[0040] (3) Axial center and longitudinal center of the module case In a hollow fiber membrane bundle inserted into a module case, the center of the cross-sectional surface of the hollow fiber membrane bundle is the axial center, and the line perpendicular to it is defined as the length direction.

[0041] (4) Leakage air volume test The first fluid outlet 14 and second fluid inlet 15 of the device consisting of the module and housing shown in Figure 1 were closed, and a pneumatic pressure of 50 kPa was applied from the first fluid inlet 13. At this time, the amount of air coming out of the second fluid outlet 16 was measured and recorded as the amount of leaked air.

[0042] (5) Conduction pressure loss test In the device consisting of the module and housing shown in Figure 1, electrical conduction was initiated from the first fluid inlet 13, and the gas discharged from the first fluid outlet 14 was humidified to a predetermined dew point by adding water vapor in a separate circuit. This humidified gas was then supplied to the second fluid inlet 15 and discharged from the second fluid outlet 16 to stabilize the system. The differential pressure between the first fluid inlet pressure measurement point 17 and the first fluid outlet pressure measurement point 18 was defined as the internal conduction pressure loss of the hollow fiber membrane. Furthermore, the differential pressure between the second fluid inlet pressure measurement point 19 and the second fluid outlet pressure measurement point 20 was defined as the external conduction pressure loss of the hollow fiber membrane.

[0043] (6) Humidification performance test In the module configured in the aforementioned conduction pressure loss test, air with a dew point (Dpdi) of -40°C and a temperature of 20°C is supplied at a predetermined flow rate from the first fluid inlet 13 to the first fluid outlet 14. This air is humidified to a predetermined dew point (Dpwi) by a separate humidifier, supplied to the second fluid inlet 15, and discharged to the second fluid outlet 16. After the values ​​at each measurement point stabilize, the dew point (Dpdo) of the discharged air from the first fluid outlet 14 and the dew point (Dpwo) of the discharged air from the second fluid outlet 16 are measured, and the humidification efficiency (Eh), defined by the amount of moisture at the inner outlet of the hollow fiber membrane relative to the amount of moisture at the outer inlet of the hollow fiber membrane, and the overall mass transfer coefficient (Ko) are calculated. Eh = Wdo / Wwi × 100% Ko = M / A / (ΔW)m (ΔW)m=(ΔW2-ΔW1) / (Ln(ΔW2 / ΔW1) Here, Wdo is the amount of air moisture at the inner outlet of the hollow fiber calculated from Dpdo, Wwi is the amount of air moisture at the outer inlet of the hollow fiber membrane calculated from Dpwi, Ko is the overall mass transfer coefficient (m / h), M is the mass transfer rate (g / h), and A is the effective membrane area converted to inner diameter (m²). 2 ), (ΔW)m is the logarithmic mean difference in moisture content (g / m^3), and ΔW1 and ΔW2 represent the difference in moisture content at the first fluid inlet 13 and the first fluid outlet 14, calculated from the dew points of the respective air.

[0044] The method for manufacturing the hollow fiber membrane module of the present invention will be described in more detail below with reference to examples and figures, but the present invention is not limited to these.

[0045] [Example 1] A film-forming stock solution consisting of 27 parts by mass of polysulfone resin (Solvay P3500), 3.5 parts by mass of polyvinylpyrrolidone (ISP K30), 68.5 parts by mass of dimethylacetamide, and 1 part by mass of water was dissolved at 90°C, then kept warm at 50°C, and simultaneously discharged from a double-ring nozzle with a core solution consisting of 30.5 parts of dimethylacetamide and 69.5 parts of water. The mixture passed through a 350 mm dry section at 30°C and was immersed in a 40°C coagulation bath consisting of 90 parts of water and 10 parts of dimethylacetamide to coagulate. The coagulated hollow fiber membrane was then washed in an 80°C water bath, and 170 dtex polyester processed yarn was wound around two hollow fiber membranes. After covering, the membrane was wound onto a winding skein. The wound hollow fiber membrane was dried in a 50°C dry heat dryer for 24 hours to obtain a hollow fiber membrane bundle.

[0046] A cylindrical protective net made of polyester was placed inside a cylindrical module case as shown in Figure 2. A bundle of 2510 hollow fiber membranes made of polysulfone, with an outer diameter of 816 μm and an inner diameter of 630 μm, was inserted into the net using a slippery film. This module case has an inner diameter of 55 mm, a thickness of 5 mm, and a length of 220 mm, and has 14 large-diameter holes of φ18 mm and 2 small-diameter holes of φ8 mm positioned as shown in Figure 8 / Table 1. The opening centers, opening areas, and opening ratios are shown in the table. The area of ​​the large inlet and outlet groups viewed from the inside of the module case was 18.7% of the total internal surface area of ​​half the module case, while the area of ​​the small inlet and outlet groups viewed from the inside of the module case was 0.5% of the total internal surface area of ​​half the module case. All large inlets and outlets were located at a position of 15 mm or more from one end face of the module case and no more than 75% of half the module case length from one end face. All small inlets and outlets were located at a position of 15 mm or more from one end face of the module case and no more than 35% of half the module case length from one end face. After sealing both ends of the hollow fiber membrane bundle, centrifugal potting was performed to cut both ends and open the hollow fiber membrane. The condition of the fiber bundle was checked from this opening in the module case to confirm that the fiber bundle was in close contact with the inner wall of the module case.

[0047] This module case was assembled using a support to create a cylindrical module, with a header section having internal fluid inlets for the hollow fiber membrane at both ends, and a port section having external fluid inlets for the hollow fiber membrane, each sealed with an O-ring. The membrane area, based on the inner diameter of the hollow fiber membrane, was 0.85 m². 2 The ratio of the sum of the cross-sectional areas based on the outer diameter of the hollow fiber membrane in the hollow fiber membrane bundle to the cross-sectional area based on the inner diameter of the module case (hereinafter referred to as the packing rate) was 50%. The amount of leaked air from this hollow fiber membrane module was 1 L / min or less, and no damage to the hollow fiber membrane was observed. Using this hollow fiber membrane module, humidification performance was evaluated by supplying air with a dew point of -40°C to the inside of the hollow fiber membrane at 400 NLM and humid air with a dew point of 90°C to the outside of the hollow fiber membrane. The humidification efficiency of this hollow fiber membrane module was 55%, and the overall mass transfer coefficient was 0.066 g / cm³. 2 The pressure was / hr / kPa, and the electrical pressure loss on the outside of the hollow fiber membrane was 40kPa. [Example 2] Except for changing the number of small inlets and outlets, the procedure was the same as in Example 1, and the membrane area based on the inner diameter of the hollow fiber membrane was 0.94 m². 2, a hollow fiber membrane module with a filling rate of 55% was fabricated. In the evaluation of the humidification performance of this hollow fiber membrane module, the humidification efficiency was 60%, the overall mass transfer coefficient was 0.070 g / cm 2 / hr / kPa, and the pressure loss of the outer side of the hollow fiber membrane was as low as 20 kPa. Since the aperture ratios of the group with small inlets (in / small) and the group with small outlets (out / small) were slightly high at 3.7%, some air leakage from the hollow fiber membrane was confirmed during the 100-hour evaluation period. [Example 3] The number of small inlets and small outlets was changed, and all large inlets and large outlets were the same as in Example 1 except that they were located in the region from 15 mm or more from one end face of the module case to 80% or less of half of the module case length. A hollow fiber membrane module with a membrane area of 0.94 m based on the inner diameter of the hollow fiber membrane was fabricated with a filling rate of 55%. 2 , a hollow fiber membrane module with a filling rate of 55% was fabricated. In the evaluation of the humidification performance of this hollow fiber membrane module, the humidification efficiency was 57%, the overall mass transfer coefficient was 0.067 g / cm 2 / hr / kPa, and the pressure loss of the outer side of the hollow fiber membrane was a slight value of 21 kPa, and no increase in air leakage was observed even after the evaluation time exceeded 100 hours. [Example 4] All large inlets and large outlets were the same as in Example 3 except that they were located in the region from 15 mm or more from one end face of the module case to 75% or less of half of the module case length. A hollow fiber membrane module with a membrane area of 0.94 m based on the inner diameter of the hollow fiber membrane was fabricated with a filling rate of 55%. 2 , a hollow fiber membrane module with a filling rate of 55% was fabricated. In the evaluation of the humidification performance of this hollow fiber membrane module, it showed good performance with a humidification efficiency of 60%. Also, the overall mass transfer coefficient of this hollow fiber membrane module at this time was 0.070 g / cm 2 / hr / kPa, and the pressure loss of the outer side of the hollow fiber membrane was a slight value of 22 kPa.

[0048]

Table 1

[0049] In the table, "Group (In / Large) Opening Area" refers to the area of ​​the Group (In / Large) as viewed from the inside of the module case. "Group (In / Large) Opening Ratio" refers to the ratio of the area of ​​the Group (In / Large) as viewed from the inside of the module case to the total internal surface area of ​​half the length of the module case.

[0050] "Circumferential position of the center (inlet / large)" refers to the circumferential position of the module case with the center (inlet / large) as the starting point, "Circumferential position of the center (outlet / large)" refers to the circumferential position of the module case with the center (inlet / large) as the starting point, "Circumferential position of the center (inlet / small)" refers to the circumferential position of the module case with the center (inlet / large) as the starting point, and "Circumferential position of the center (outlet / small)" refers to the circumferential position of the module case with the center (outlet / large) as the starting point.

[0051] [Comparative Example 1] Except for the absence of small inlet and outlet sections, the configuration is the same as in Example 1, resulting in a membrane area of ​​0.81 m² relative to the inner diameter of the hollow fiber membrane, as shown in Figure 5. 2 A hollow fiber membrane module with a filling rate of 50% was created. In the humidification performance evaluation of this hollow fiber membrane module, the humidification efficiency was 53%, and the overall mass transfer coefficient was 0.065 g / cm³. 2 Although the pressure was / hr / kPa, the electrical pressure loss on the outside of the hollow fiber membrane was a high value of 52kPa. [Explanation of symbols]

[0052] 1. Hollow fiber membrane 2. Hollow fiber membrane opening 3. Potting material 4. Protective net 5. Large Inlet 6.Large outlet 7.Inlet small 8. Outlet small 9. Module Case 10.Hollow fiber membrane bundle 11. Header section 12. Port Section 13.First fluid inlet 14.First fluid outlet 15.Second fluid inlet 16.Second fluid outlet 17. First fluid inlet pressure measurement point 18. First fluid outlet pressure measurement point 19. Second fluid inlet pressure measurement point 20. Second fluid outlet pressure measurement point 21. Supports 22. Enclosure 23. O-ring

Claims

1. A hollow fiber membrane module having a bundle of hollow fiber membranes inside a cylindrical module case, At both ends of the hollow fiber membrane module, the hollow fiber membrane is open, and the gaps between the hollow fiber membranes and between the hollow fiber membrane and the module case are sealed with potting material. The module case has a region A extending from one end face of the module case to half the length of the module case and within 150° in the circumferential direction of the module case, and a region B extending within 210° at an opposite position in the circumferential direction of region A. The module case has a region C extending from the other end face of the module case to half the length of the module case and within 150° in the circumferential direction of the module case, and a region D at an opposite position in the circumferential direction of region C, within 210°. Region A contains only inlets with a diameter of less than 10 mm (hereinafter referred to as "small inlets"), all small inlets within region A are collectively called a group (inlet / small), and the center of this group (inlet / small) is called the center (inlet / small). Region B has inlets with a diameter of 10 mm or more and 30 mm or less (hereinafter referred to as "large inlets"), and all the large inlets within region B are collectively called a group (inlet / large), and the center of the group (inlet / large) is called the center (inlet / large). Region C contains only outlets with a diameter of less than 10 mm (hereinafter referred to as "small outlets"), all small outlets within region C are collectively called a group (outlet / small), and the center of this group (outlet / small) is called the center (outlet / small). Region D has outlets with a diameter of 10 mm or more and 30 mm or less (hereinafter referred to as "large outlets"), and all the large outlets within region D are collectively called a group (outlet / large), and when the center of the group (outlet / large) is designated as the center (outlet / large), The aforementioned center (outward / large) is positioned at a position of 180 ± 30° from the aforementioned center (inward / large) in the circumferential direction of the module case. The aforementioned center (in / small) is positioned at a position 180 ± 30° from the aforementioned center (in / large) in the circumferential direction of the module case. The aforementioned center (small projection) is positioned at a position 180 ± 30° from the aforementioned center (large projection) in the circumferential direction of the module case. Hollow fiber membrane module.

2. The area of ​​the module case viewed from the inside of the aforementioned group (in / large) and the area of ​​the module case viewed from the inside of the aforementioned group (out / large) are, respectively, 5.0% to 30.0% of the internal surface area of ​​half the length of the entire module case. The hollow fiber membrane module according to claim 1, wherein the area of ​​the group (in / small) as viewed from the inside of the module case and the area of ​​the group (out / small) as viewed from the inside of the module case are each 1.0 to 3.0% of the internal surface area of ​​half the length of the entire module case.

3. The large inlet is located in a region of 15 mm or more from one end face of the module case and no more than 75% of half the length of the module case from the other end face of the module case, and the large outlet is located in a region of 15 mm or more from the other end face of the module case and no more than 75% of half the length of the module case from the other end face of the module case. The hollow fiber membrane module according to claim 1, characterized in that the small inlet is located in a region of 15 mm or more from one end face of the module case and no more than 35% of half the length of the module case from one end face of the module case, and the small outlet is located in a region of 15 mm or more from the other end face of the module case and no more than 35% of half the length of the module case from the other end face of the module case.

4. The hollow fiber membrane module according to claim 1, characterized in that a protective net is placed between the module case and the hollow fiber membrane bundle.

5. The hollow fiber membrane module according to claim 1, characterized in that the ratio of the sum of the volumes based on the outer diameter of the hollow fiber membrane to 100% of the internal volume of the module case is 50% or more and 65% or less.

6. A fuel cell humidifier in which the center (inlet / outlet) of the hollow fiber membrane module according to any one of claims 1 to 5 is positioned 180 ± 30° opposite on the circumference to the fluid inlet of a housing having a port portion.

7. A stationary fuel cell comprising a hollow fiber membrane module according to any one of claims 1 to 5.

8. A fuel cell vehicle comprising a hollow fiber membrane module according to any one of claims 1 to 5.

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