Hollow fiber membrane module, degassing device, air supply device and adjustment device

Abstract

The aim is to achieve a balance between suppressing the deterioration of the hollow fiber membrane, improving handling, and suppressing the adhesion of dirt. [Solution] The hollow fiber membrane module 100 comprises a hollow fiber membrane bundle 103 in which a plurality of hollow fiber membranes 102 are bundled together, and a housing 104 that houses the hollow fiber membrane bundle 103. The space inside the housing 104 is divided by the plurality of hollow fiber membranes 102 as boundaries into an internal space S101 that includes the hollow portion 102a of each of the plurality of hollow fiber membranes 102, and an external space S102 that does not include the hollow portion 102a of each of the plurality of hollow fiber membranes 102. The surface roughness Ra of the inner surface 104a of the housing 104 is smaller than the surface roughness Ra of the outer surface 104b of the housing 104.

Description

Technical Field

[0001] The present disclosure relates to a hollow fiber membrane module in which a plurality of hollow fiber membranes are housed in a housing, a degassing device, an air supply device, and an adjustment device.

Background Art

[0002] Conventionally, a hollow fiber membrane module in which a plurality of hollow fiber membranes are housed in a housing has been known (see, for example, Patent Document 1). The hollow fiber membrane module is used, for example, as a degassing module for degassing a liquid, a gas addition module for adding a gas to a liquid, and the like.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, the housing in which the hollow fiber membrane bundle is housed is manufactured by injection molding or the like. Conventionally, the surface roughness has not been made different between the inner surface and the outer surface of the housing, and the necessity has not been recognized.

[0005] However, as a result of research by the present disclosure author, different functions are required between the inner surface and the outer surface of the housing, and it has been found that it is effective to make the surface roughness different between the inner surface and the outer surface of the housing in order to realize the functions.

[0006] During the manufacturing of hollow fiber membrane modules, multiple hollow fiber membranes are inserted into a housing. At this time, some of the hollow fiber membranes may come into contact with and rub against the inner surface of the housing. Furthermore, during the use of the hollow fiber membrane module, some of the hollow fiber membranes may come into contact with and rub against the inner surface of the housing due to the flow of the liquid supplied to the module or the swelling of the multiple hollow fiber membranes. Therefore, if the surface roughness of the inner surface of the housing is large, the hollow fiber membranes are more susceptible to deterioration due to friction with the inner surface of the housing. For these reasons, the inner surface of the housing is required to have a function that suppresses the deterioration of the hollow fiber membranes, and this function is effectively achieved by reducing the surface roughness of the inner surface of the housing.

[0007] On the other hand, during the transport and installation of hollow fiber membrane modules, the modules are held by human hands, jigs, or robotic arms. In this case, if the surface roughness of the outer surface of the housing is low, the housing becomes slippery, reducing the handling of the hollow fiber membrane modules. Also, during storage and use, the hollow fiber membrane modules are left unattended for long periods of time. Therefore, if the surface roughness of the outer surface of the housing is low, dirt such as dust is more likely to adhere to the outer surface of the housing. When dirt adheres to the housing, the housing deteriorates more easily. For these reasons, the outer surface of the housing needs to have a function that improves handling and suppresses the adhesion of dirt, and this function is effectively achieved by increasing the surface roughness of the outer surface of the housing.

[0008] Therefore, this disclosure is, Compared to the case where the inner and outer surfaces of the housing have the same surface roughness, The objective is to provide a hollow fiber membrane module that can achieve both suppression of hollow fiber membrane deterioration, improved handling, and suppression of dirt adhesion. [Means for solving the problem]

[0009] [1] The hollow fiber membrane module according to the present disclosure comprises a hollow fiber membrane bundle in which a plurality of hollow fiber membranes are bundled together, and a housing that houses the hollow fiber membrane bundle, wherein the space within the housing is divided by the plurality of hollow fiber membranes into an internal space that includes the hollow portion of each of the plurality of hollow fiber membranes and an external space that does not include the hollow portion of each of the plurality of hollow fiber membranes, and the surface roughness Ra of the inner surface of the housing is smaller than the surface roughness Ra of the outer surface of the housing.

[0010] In this hollow fiber membrane module, the surface roughness Ra of the inner surface of the housing is smaller than the surface roughness Ra of the outer surface of the housing. Therefore, compared to the case where the surface roughness Ra of the inner surface of the housing and the surface roughness Ra of the outer surface of the housing are the same, it is possible to achieve both suppression of hollow fiber membrane deterioration, improved handling, and suppression of dirt adhesion.

[0011] [2] In the hollow fiber membrane module described in [1], the surface roughness Ra of the inner surface of the housing may be 0.1 μm or more and less than 2.0 μm. In this hollow fiber membrane module, the surface roughness Ra of the inner surface of the housing is 0.1 μm or more and less than 2.0 μm. Therefore, deterioration when the hollow fiber membrane rubs against the inner surface of the housing can be appropriately suppressed.

[0012] [3] In the hollow fiber membrane module described in [1] or [2], the surface roughness Ra of the outer surface of the housing may be 2.0 μm or more and 10 μm or less. In this hollow fiber membrane module, the surface roughness Ra of the outer surface of the housing is 2.0 μm or more and 10 μm or less. Therefore, the handling of the hollow fiber membrane module can be appropriately improved, and the adhesion of dirt to the outer surface of the housing can be appropriately suppressed.

[0013] [4] A hollow fiber membrane module according to any of [1] to [3] further comprises a first fixing part for fixing a first membrane bundle end, which is one end of the hollow fiber membrane bundle, to the housing, and a second fixing part for fixing a second membrane bundle end, which is the other end of the hollow fiber membrane bundle, to the housing, wherein the housing may have a first external space port opening to the external space between the first fixing part and the second fixing part, a second external space port communicating with the external space, an internal space port communicating with the internal space, and a baffle disposed between the hollow fiber membrane bundle and the first external space port.

[0014] In this hollow fiber membrane module, the first and second ends of the hollow fiber membrane bundle are fixed to the housing by a first and second fixing part, respectively. The housing has a first external space port opening to the external space between the first and second fixing parts, a second external space port communicating with the external space, an internal space port communicating with the internal space, and a baffle positioned between the hollow fiber membrane bundle and the first external space port. Therefore, when liquid is supplied to the external space from the second external space port, the liquid passes between the multiple hollow fiber membranes, flows around the baffle positioned between the hollow fiber membrane bundle and the first external space port, and is discharged from the first external space port. At this time, the liquid supplied to the external space can be degassed by sucking the internal space from the internal space port, and gas can be added to the liquid supplied to the external space by supplying gas to the internal space from the internal space port.

[0015] In the hollow fiber membrane module described in [5] [4], the surface roughness Ra of the inner surface of the baffle opposite to the first external space port may be greater than the surface roughness Ra of the inner surface of the housing other than the baffle.

[0016] In this hollow fiber membrane module, when the module is used as an external perfusion type module, the liquid supplied to the external space flows around a baffle positioned between the hollow fiber membrane bundle and the first external space port, and then flows into the first external space port. As a result, the hollow fiber membrane in contact with the inner surface of the baffle tends to vibrate significantly due to the force of the liquid flowing around the baffle and into the first external space port. When a large flow rate of liquid is supplied to the external space at this time, the force of the liquid flowing around the baffle and into the first external space port causes some of the hollow fiber membrane to be strongly pressed against the inner surface of the baffle. As a result, the surface roughness Ra of the inner surface of the baffle is greater than the surface roughness Ra of the inner surface of the housing other than the baffle. Therefore, friction between the hollow fiber membrane and the baffle causes the hollow fiber membrane to adhere closely to the inner surface of the baffle, suppressing the vibration of the hollow fiber membrane. This prevents a significant difference in the deterioration state of the hollow fiber membrane between the portion in contact with the inner surface of the baffle and the portion in contact with the inner surface of the housing other than the baffle when a large flow rate of liquid is supplied to the external space.

[0017] In the hollow fiber membrane module described in [6] [4], the surface roughness Ra of the inner surface of the baffle opposite to the first external space port may be smaller than the surface roughness Ra of the inner surface of the housing other than the baffle.

[0018] In this hollow fiber membrane module, when the module is used as an external perfusion type module, the liquid supplied to the external space flows around a baffle positioned between the hollow fiber membrane bundle and the first external space port, and then flows into the first external space port. As a result, the hollow fiber membrane in contact with the inner surface of the baffle tends to vibrate significantly due to the force of the liquid flowing around the baffle and into the first external space port. At this time, if a small flow rate of liquid is supplied to the external space, the hollow fiber membrane is not strongly pressed against the inner surface of the baffle by the force of the liquid flowing around the baffle and into the first external space port, so the vibration of the hollow fiber membrane in contact with the inner surface of the baffle becomes large. However, the surface roughness Ra of the inner surface of the baffle is smaller than the surface roughness Ra of the inner surfaces of the housing other than the baffle. Therefore, even if the hollow fiber membrane rubs against the inner surface of the baffle, the deterioration of the hollow fiber membrane is suppressed. This prevents a significant difference in the deterioration state of the hollow fiber membrane between the portion in contact with the inner surface of the baffle and the portion in contact with the inner surface of the housing other than the baffle when a small flow rate of liquid is supplied to the external space.

[0019] In the hollow fiber membrane module described in any of [7] [4] to [6], the first fixing part seals the region of the hollow fiber membrane bundle other than the hollow portion in a cross section perpendicular to the direction of extension of the hollow fiber membrane bundle passing through the end of the first membrane bundle, the second fixing part seals the region of each of the multiple hollow fiber membranes other than the hollow portion in a cross section perpendicular to the direction of extension of the hollow fiber membrane bundle passing through the end of the second membrane bundle, the second external space port opens to the external space on the opposite side of the second fixing part to the first fixing part, and the internal space port may open to the internal space on the opposite side of the first fixing part to the second fixing part.

[0020] In this hollow fiber membrane module, in a cross-section perpendicular to the direction of extension of the hollow fiber membrane bundle passing through the end of the first membrane bundle, the region of the hollow fiber membrane bundle other than the hollow portion is sealed by the first fixing portion. Similarly, in a cross-section perpendicular to the direction of extension of the hollow fiber membrane bundle passing through the end of the second membrane bundle, the region of each of the multiple hollow fiber membranes other than the hollow portion is sealed by the second fixing portion. Therefore, within the housing, the space opposite the first fixing portion to the second fixing portion becomes the internal space, and the space opposite the second fixing portion to the first fixing portion becomes the external space. Furthermore, since the second external space port opens into the external space opposite the second fixing portion to the first fixing portion, the second external space port can be connected to the hollow portion of the hollow fiber membrane bundle. Additionally, since the internal space port opens into the internal space opposite the first fixing portion to the second fixing portion, the internal space port can be connected to the hollow portion of each of the multiple hollow fiber membranes.

[0021] In the hollow fiber membrane module described in any of [8] [4] to [7], the housing may further have a second internal space port that communicates with the internal space. In this hollow fiber membrane module, there are two ports that communicate with the internal space: an internal space port and a second internal space port. For example, when the hollow fiber membrane module is used as an external perfusion type module to add gas to a liquid, the gas in the internal space can be replaced by supplying gas to either the internal space port or the second internal space port and discharging the gas from the other of the internal space port or the second internal space port, thereby suppressing changes in the gas concentration in the internal space.

[0022] In the hollow fiber membrane module described in any of [9] [4] to [8], an inner support may be further provided, which is positioned in the hollow portion of the hollow fiber membrane bundle and supports the hollow fiber membrane bundle from the inner circumferential side. In this hollow fiber membrane module, the hollow fiber membrane bundle is supported from the inner circumferential side by the inner support. Therefore, when multiple hollow fiber membranes swell, it is possible to suppress the multiple hollow fiber membranes from entering the hollow portion of the hollow fiber membrane bundle and narrowing or blocking the hollow portion. This makes it possible to suppress an increase in the pressure loss of the liquid flowing through the hollow portion of the hollow fiber membrane bundle.

[0023]

[10] In the hollow fiber membrane module according to any one of [4] to [9], a net-like member covering the hollow fiber membrane bundle may be further provided. In this hollow fiber membrane module, the hollow fiber membrane bundle is covered by the net-like member. Therefore, by disposing the net-like member between the hollow fiber membrane bundle and the housing, it is possible to reduce the contact area between the hollow fiber membrane and the housing while ensuring the flow of liquid. Thereby, deterioration of the hollow fiber membrane due to rubbing against the housing can be suppressed.

[0024]

[11] The degassing device according to the present disclosure includes the hollow fiber membrane module according to any one of [1] to

[10] , a liquid supply pipe communicating with the second external space port, a suction pipe communicating with the internal space port, and a suction device that suctions the internal space port through the suction pipe.

[0025] In this degassing device, by suctioning the internal space port of the hollow fiber membrane module through the suction pipe by the suction device, the liquid supplied from the liquid supply pipe to the second external space port of the hollow fiber membrane module can be degassed. Moreover, since the above-described hollow fiber membrane module is provided, it is possible to degas the liquid while achieving both suppression of deterioration of the hollow fiber membrane, improvement in handling property, and suppression of adhesion of dirt.

[0026]

[12] The air supply device according to the present disclosure includes the hollow fiber membrane module according to any one of [1] to

[10] , a liquid supply pipe communicating with the second external space port, a gas supply pipe communicating with the internal space port, and a gas supply device that supplies gas to the internal space port through the gas supply pipe.

[0027] In this air supply device, by supplying gas to the internal space port of the hollow fiber membrane module through the gas supply pipe by the gas supply device, gas can be added to the liquid supplied from the liquid supply pipe to the second external space port of the hollow fiber membrane module. Moreover, since the above-described hollow fiber membrane module is provided, it is possible to add gas to the liquid while achieving both suppression of deterioration of the hollow fiber membrane, improvement in handling property, and suppression of adhesion of dirt.

[0028]

[13] The adjustment device according to the present disclosure comprises a hollow fiber membrane module as described in any of [1] to

[10] , a liquid supply pipe communicating with a second external space port, a liquid discharge pipe communicating with a first external space port, a gas supply pipe communicating with an internal space port, a gas supply device supplying gas to the internal space port through the gas supply pipe, and a bypass pipe communicating with a branch of the liquid supply pipe and a junction of the liquid discharge pipe so as to bypass the hollow fiber membrane module.

[0029] In this adjustment device, the liquid supplied to the liquid supply pipe is divided at the branching point into liquid supplied to the hollow fiber membrane module and liquid that bypasses the hollow fiber membrane module. At the confluence point, the liquid to which gas has been added in the hollow fiber membrane module and the liquid that bypasses the hollow fiber membrane module merge. Therefore, by adjusting the distribution ratio at the branching point, the amount of liquid supplied, the amount of gas supplied, etc., the dissolved gas concentration in the liquid supplied to the liquid supply pipe can be adjusted. Moreover, because it is equipped with the aforementioned hollow fiber membrane module, it is possible to adjust the dissolved gas concentration in the liquid while simultaneously suppressing deterioration of the hollow fiber membrane, improving handling, and suppressing the adhesion of dirt. [Effects of the Invention]

[0030] According to this disclosure, it is possible to achieve both suppression of hollow fiber membrane deterioration, improved handling, and suppression of dirt adhesion. [Brief explanation of the drawing]

[0031] [Figure 1] This is a schematic cross-sectional view of a hollow fiber membrane module according to an embodiment. [Figure 2] This is a schematic cross-sectional view of a portion of the hollow fiber membrane module shown in Figure 1. [Figure 3] This is a schematic cross-sectional view of a portion of the hollow fiber membrane module shown in Figure 1. [Figure 4] This is a schematic diagram of a degassing device according to an embodiment. [Figure 5]This is a schematic diagram of an air supply device according to an embodiment. [Figure 6] This is a schematic diagram of the adjustment device according to the embodiment. [Figure 7] This is a schematic cross-sectional view of a modified hollow fiber membrane module. [Figure 8] This is a schematic cross-sectional view of a modified hollow fiber membrane module. [Figure 9] This is a schematic cross-sectional view of a modified hollow fiber membrane module. [Modes for carrying out the invention]

[0032] The hollow fiber membrane module, degassing device, air supply device, and adjustment device of the embodiment will be described in detail below with reference to the drawings. In all the drawings, the same or corresponding parts are denoted by the same reference numerals, and redundant descriptions are omitted.

[0033] [Hollow fiber membrane module] Figure 1 is a schematic cross-sectional view of a hollow fiber membrane module according to an embodiment. Figure 2 is an enlarged schematic cross-sectional view of a part of the hollow fiber membrane module shown in Figure 1. Figure 3 is an enlarged schematic cross-sectional view of a part of the hollow fiber membrane module shown in Figure 1. As shown in Figures 1 to 3, the hollow fiber membrane module 100 according to this embodiment comprises a hollow fiber membrane bundle 103 in which a plurality of hollow fiber membranes 102 are bundled together in a cylindrical shape, and a cylindrical housing 104 that houses the hollow fiber membrane bundle 103. The direction in which the hollow fiber membrane bundle 103 extends is called the extension direction D. The extension direction D is also the direction along the central axis A of the hollow fiber membrane bundle 103.

[0034] The space within the housing 104 is divided by the multiple hollow fiber membranes 102 as boundaries into an internal space S101 that includes the hollow portions 102a of each of the multiple hollow fiber membranes 102, and an external space S102 that does not include the hollow portions 102a of each of the multiple hollow fiber membranes 102. The external space S102 includes the hollow portion 103a of the hollow fiber membrane bundle 103, the space between the multiple hollow fiber membranes 102 in the hollow fiber membrane bundle 103, and the space between the hollow fiber membrane bundle 103 and the housing 104. The hollow portion 103a is a hollow part located in the radial center of the hollow fiber membrane bundle 103.

[0035] The inner surface (internal space side) of the housing 104 is called the inner surface 104a, and the outer surface of the housing 104 is called the outer surface 104b. The inner surface 104a is the surface that defines the internal space S101 and the external space S102. The outer surface 104b is the surface that is exposed to the outside of the hollow fiber membrane module 100.

[0036] The hollow fiber membrane 102 is a hollow fiber membrane that allows gas to pass through but not liquid. The material, membrane shape, and membrane morphology of the hollow fiber membrane 102 are not particularly limited. Examples of materials for the hollow fiber membrane 102 include polyolefin resins such as polypropylene, polyethylene, and polymethylpentene, silicone resins such as polydimethylsiloxane and its copolymers, and fluorine resins such as polytetrafluoroethylene (PTFE) and vinylidene fluoride. Examples of membrane shapes (sidewall shapes) of the hollow fiber membrane 102 include porous membranes, microporous membranes, and homogeneous membranes (non-porous membranes) that do not have porosity. Examples of membrane morphologies of the hollow fiber membrane 102 include symmetrical membranes (homogeneous membranes) in which the chemical or physical structure of the entire membrane is homogeneous, and asymmetrical membranes (heterogeneous membranes) in which the chemical or physical structure of the membrane differs depending on the part of the membrane. An asymmetrical membrane (heterogeneous membrane) is a membrane that has a non-porous dense layer and a porous layer. In this case, the dense layer may be formed anywhere in the membrane, such as on the surface or inside the porous membrane. Heterogeneous membranes also include composite membranes with different chemical structures and multilayer membranes such as three-layer structures. Heterogeneous membranes using poly-4-methylpentene-1 resin are particularly suitable for degassing liquids other than water, such as ink, because they have a dense layer that blocks liquids. Furthermore, when used in an external perfusion type, it is preferable that the dense layer is formed on the outer surface of the hollow fiber.

[0037] As shown in Figure 1, the housing 104 comprises a cylindrical portion 105, a first lid portion 106, and a second lid portion 107.

[0038] The cylindrical portion 105 is the part that houses the hollow fiber membrane bundle 103. The cylindrical portion 105 is formed in a cylindrical shape with both ends open. The hollow fiber membrane bundle 103 is housed in the cylindrical portion 105 such that the extending direction D of the cylindrical portion 105 and the extending direction D of the hollow fiber membrane bundle 103 are substantially the same. The first membrane bundle end 103b, which is one end of the hollow fiber membrane bundle 103, is fixed to the first open end 105a, which is one end of the cylindrical portion 105, by the first fixing portion 108. The second membrane bundle end 103c, which is the other end of the hollow fiber membrane bundle 103, is fixed to the second open end 105b, which is the other end of the cylindrical portion 105, by the second fixing portion 109.

[0039] As shown in Figures 1 and 2, the first fixing portion 108 is made of resin. Examples of resins used for the first fixing portion 108 include epoxy resin, urethane resin, UV-curing resin, and polyolefin resins such as polyethylene and polypropylene. The first fixing portion 108 seals the region of the hollow fiber membrane bundle 103 other than the hollow portion 103a in a cross section perpendicular to the extending direction D of the hollow fiber membrane bundle 103, passing through the first membrane bundle end 103b. In other words, the first fixing portion 108 fills the hollow portions 102a of each of the multiple hollow fiber membranes 102, the spaces between the multiple hollow fiber membranes 102 in the hollow fiber membrane bundle 103, and the space between the hollow fiber membrane bundle 103 and the cylindrical portion 105. The first fixing portion 108 has a communication opening 108a that opens the hollow portion 103a of the hollow fiber membrane bundle 103. The first fixing portion 108 may be provided in a part of the hollow portion 103a of the hollow fiber membrane bundle 103, provided that the hollow portion 103a of the hollow fiber membrane bundle 103 is open.

[0040] As shown in Figures 1 and 3, the second fixing portion 109 is made of the same resin as the first fixing portion 108. The second fixing portion 109 seals the areas within the cylindrical portion 105 other than the hollow portions 102a of each of the multiple hollow fiber membranes 102 in a cross section perpendicular to the extending direction D of the hollow fiber membrane bundle 103, passing through the second membrane bundle end 103c. In other words, the second fixing portion 109 does not fill the hollow portions 102a of each of the multiple hollow fiber membranes 102, but fills the spaces between the multiple hollow fiber membranes 102 in the hollow fiber membrane bundle 103, the space between the hollow fiber membrane bundle 103 and the cylindrical portion 105, and the hollow portion 103a of the hollow fiber membrane bundle 103.

[0041] As shown in Figure 1, the cylindrical portion 105 has a first external space port 105c and a baffle 105d formed therein.

[0042] The first external space port 105c is in communication with the external space S102. The first external space port 105c connects the external space S102 with the outside of the hollow fiber membrane module 100. The first external space port 105c is formed in the side wall of the cylindrical portion 105 between the first fixing portion 108 and the second fixing portion 109, and opens to the external space S102 between the first fixing portion 108 and the second fixing portion 109.

[0043] The baffle 105d is a roughly plate-shaped portion positioned between the hollow fiber membrane bundle 103 and the first external space port 105c. The baffle 105d prevents liquid supplied to the external space S102 from flowing directly into the first external space port 105c when liquid is supplied to the external space S102. For this reason, the baffle 105d is also called a baffle plate. The baffle 105d is formed so as to cover the first external space port 105c, and is positioned to overlap the first external space port 105c when viewed from the direction along the central axis B of the first external space port 105c (the direction of extension of the first external space port 105c). Therefore, the baffle 105d divides the external space S102 between the first fixing part 108 and the second fixing part 109 into an internal space S105 on the opposite side of the first external space port 105c to the baffle 105d, and an external space S106 on the side of the first external space port 105c to the baffle 105d. A communication space S107 is formed in the external space S102 that connects the internal space S105 and the external space S106, which are separated by the baffle 105d. Therefore, when liquid is supplied to the external space S102, the liquid supplied to the external space S102 flows around the baffle 105d and into the first external space port 105c. Here, the surface of the baffle 105d opposite to the first external space port 105c is called the inner surface 105e.

[0044] The first lid portion 106 is airtightly joined to the first open end 105a of the cylindrical portion 105. The joining of the first lid portion 106 to the cylindrical portion 105 can be done, for example, by screwing, fitting, welding, etc. The first lid portion 106 is formed in a shape that decreases in diameter as it moves away from the cylindrical portion 105. Inside the first lid portion 106, a first end space S103 is formed. The first end space S103 is part of the external space S102 and is in communication with the hollow portion 103a of the hollow fiber membrane bundle 103. A port 106a for the second external space is formed at the tip of the first lid portion 106.

[0045] The second external space port 106a is in communication with the external space S102. The second external space port 106a connects the external space S102 with the outside of the hollow fiber membrane module 100. The second external space port 106a is formed in the first lid portion 106 and opens to the first end space S103. That is, the second external space port 106a opens to the external space S102 on the opposite side of the second fixing portion 109 from the first fixing portion 108. Therefore, the second external space port 106a is in communication with the hollow portion 103a of the hollow fiber membrane bundle 103, making it possible to supply liquid to the hollow portion 103a of the hollow fiber membrane bundle 103.

[0046] The second lid portion 107 is airtightly joined to the second open end 105b of the cylindrical portion 105. The second lid portion 107 can be joined to the cylindrical portion 105 by, for example, screwing, fitting, welding, etc. The second lid portion 107 is formed in a shape that decreases in diameter as it moves away from the cylindrical portion 105. Inside the second lid portion 107, a second end space S104 is formed. The second end space S104 is part of the internal space S101 and is in communication with the respective hollow portions 102a of the multiple hollow fiber membranes 102. An internal space port 107a is formed at the tip of the second lid portion 107.

[0047] The internal space port 107a communicates with the internal space S101. The internal space port 107a connects each of the hollow portions 102a of the multiple hollow fiber membranes 102 to the outside of the hollow fiber membrane module 100. The internal space port 107a is formed in the second lid portion 107 and opens to the second end space S104. That is, the internal space port 107a opens to the internal space S101 on the side opposite to the first fixing portion 108 relative to the second fixing portion 109.

[0048] Incidentally, during the manufacturing of the hollow fiber membrane module 100, the hollow fiber membrane bundle 103 is inserted into the housing 104 (cylindrical portion 105). At this time, some of the hollow fiber membranes 102 may come into contact with and rub against the inner surface 104a of the housing 104 (cylindrical portion 105). Furthermore, during the use of the hollow fiber membrane module 100, some of the hollow fiber membranes 102 may come into contact with and rub against the inner surface 104a of the housing 104 (cylindrical portion 105) due to the flow of liquid supplied to the hollow fiber membrane module 100 or the swelling of the multiple hollow fiber membranes 102. For this reason, if the surface roughness of the inner surface 104a of the housing 104 is large, the hollow fiber membranes 102 are more likely to deteriorate due to friction with the inner surface 104a of the housing 104.

[0049] On the other hand, when transporting and installing the hollow fiber membrane module 100, the module 100 is held by human hands, jigs, robot arms, etc. At this time, if the surface roughness of the outer surface 104b of the housing 104 is small, the housing 104 becomes slippery, reducing the handling of the hollow fiber membrane module 100. Also, when storing and using the hollow fiber membrane module 100, the module 100 is left unattended for long periods of time. Therefore, if the surface roughness of the outer surface 104b of the housing 104 is small, dirt such as dust is more likely to adhere to the outer surface 104b of the housing 104. When dirt adheres to the housing, the housing deteriorates more easily. Moreover, if the surface roughness of the outer surface of the housing is small, dirt attached to the housing and scratches formed on the housing become more noticeable.

[0050] Therefore, from the viewpoint of achieving both the suppression of deterioration of the hollow fiber membrane 102 and the improvement of the handling of the hollow fiber membrane module 100 and the suppression of dirt adhesion to the housing 104, the surface roughness Ra (arithmetic mean roughness) of the inner surface 104a of the housing 104 is smaller than the surface roughness Ra (arithmetic mean roughness) of the outer surface 104b of the housing 104.

[0051] The surface roughness Ra of the inner surface 104a of the housing 104 is not particularly limited, but from the viewpoint of suppressing deterioration of the hollow fiber film 102, it is, for example, 0.1 μm or more and less than 2.0 μm, preferably 0.5 μm or more and 1.7 μm or less, and more preferably 0.8 μm or more and 1.5 μm or less.

[0052] The surface roughness Ra of the outer surface 104b of the housing 104 is not particularly limited, but from the viewpoint of improving the handling of the hollow fiber membrane module 100 and suppressing the adhesion of dirt to the housing 104, it is, for example, 2.0 μm or more and 10 μm or less, preferably 2.3 μm or more and 5.0 μm or less, and more preferably 2.5 μm or more and 3.0 μm or less.

[0053] When the hollow fiber membrane module 100 is in use, if a large flow rate of liquid is supplied to the external space S102, the force of the liquid flowing around the baffle 105d and into the first external space port 105c causes some of the hollow fiber membrane 102 to be strongly pressed against the inner surface 105e of the baffle 105d.

[0054] Therefore, when a large flow rate of liquid is supplied to the external space S102, in order to suppress a large discrepancy in the deterioration state of the hollow fiber membrane 102 between the portion in contact with the inner surface 105e of the baffle 105d and the portion in contact with the inner surface 104a of the housing 104 other than the baffle 105d, the surface roughness Ra (arithmetic mean roughness) of the inner surface 105e of the baffle 105d may be greater than the surface roughness Ra (arithmetic mean roughness) of the inner surface 104a of the housing 104 other than the baffle 105d.

[0055] On the other hand, when the hollow fiber membrane module 100 is used and a small flow rate of liquid is supplied to the external space S102, the force of the liquid flowing around the baffle 105d into the first external space port 105c prevents the hollow fiber membrane 102 from being strongly pressed against the inner surface 105e of the baffle 105d. As a result, the vibration of the hollow fiber membrane 102 in contact with the inner surface 105e of the baffle 105d increases.

[0056] Therefore, when a small flow rate of liquid is supplied to the external space S102, in order to suppress a large discrepancy in the deterioration state of the hollow fiber membrane 102 between the portion that contacts the inner surface 105e of the baffle 105d and the portion that contacts the inner surface 104a of the housing 104 other than the baffle 105d, the surface roughness Ra (arithmetic mean roughness) of the inner surface 105e of the baffle 105d may be smaller than the surface roughness Ra (arithmetic mean roughness) of the inner surface 104a of the housing 104 other than the baffle 105d.

[0057] The hollow fiber membrane module 100 configured in this way can be applied to degassing devices for removing gas from liquids, gas supply devices for adding gas to liquids, and adjustment devices for adjusting the dissolved gas concentration in liquids. Adding gas to a liquid means dissolving gas in the liquid.

[0058] The liquids to be degassed in a degasser are not particularly limited and include, for example, ultrapure water, pure water, seawater, wastewater, food, beverages, tap water, industrial water, ink, and constant temperature water. The gases to be degassed from the liquids in a degasser are not particularly limited and include, for example, oxygen, carbon dioxide, ammonia gas, and nitrogen.

[0059] Examples of such degassing equipment include: degassing equipment for removing (separating) oxygen from ultrapure water or pure water for semiconductor cleaning water applications; degassing equipment for removing (separating) carbon dioxide from ultrapure water or pure water for semiconductor cleaning water applications; degassing equipment for removing (separating) carbon dioxide from seawater for seawater decarbonation applications; degassing equipment for removing (separating) ammonia gas from wastewater for wastewater treatment applications; degassing equipment for removing (separating) oxygen, carbon dioxide, or nitrogen from food or beverages for oxidation prevention applications; degassing equipment for removing (separating) oxygen from boiler makeup water for boiler makeup water applications; degassing equipment for removing (separating) oxygen from ink for inkjet printer applications; and degassing equipment for removing (separating) oxygen from constant temperature water for biochemical analysis applications.

[0060] The liquid to be supplied in the air supply system is not particularly limited and includes, for example, ultrapure water, pure water, and ammonia water. The gas to be added to the liquid in the air supply system is not particularly limited and includes, for example, oxygen, carbon dioxide, nitrogen, and hydrogen.

[0061] Examples of such air supply devices include those that add carbon dioxide to ultrapure water or pure water for antistatic purposes, those that add oxygen, carbon dioxide, or nitrogen to ultrapure water for semiconductor cleaning water purposes, those that add hydrogen or nitrogen to ammonia water for semiconductor cleaning water purposes, and those that add oxygen, carbon dioxide, or nitrogen to food or beverages for food or beverage applications.

[0062] The liquid to which the gas to be adjusted is added in the adjustment device is not particularly limited, and examples include ultrapure water. The gas to be adjusted in the adjustment device is not particularly limited, and examples include oxygen, carbon dioxide, nitrogen, etc.

[0063] Examples of such adjustment devices include those used to adjust the dissolved concentrations of oxygen, carbon dioxide, or nitrogen in ultrapure water for semiconductor cleaning applications. These adjustment devices can also be used, for example, to adjust the resistivity of ultrapure water.

[0064] Thus, in the hollow fiber membrane module 100 according to this embodiment, the surface roughness Ra of the inner surface 104a of the housing 104 is smaller than the surface roughness Ra of the outer surface 104b of the housing 104. Therefore, compared to the case where the surface roughness Ra of the inner surface 104a of the housing 104 and the surface roughness Ra of the outer surface 104b of the housing 104 are the same, it is possible to achieve both suppression of deterioration of the hollow fiber membrane 102, improvement of handling, and suppression of dirt adhesion.

[0065] Furthermore, in this hollow fiber membrane module 100, the surface roughness Ra of the inner surface 104a of the housing 104 is 0.1 μm or more and less than 2.0 μm, preferably 0.5 μm or more and 1.7 μm or less, and more preferably 0.8 μm or more and 1.5 μm or less. Therefore, deterioration when the hollow fiber membrane 102 rubs against the inner surface 104a of the housing 104 can be appropriately suppressed.

[0066] Furthermore, in this hollow fiber membrane module 100, the surface roughness Ra of the outer surface 104b of the housing 104 is 2.0 μm or more and 10 μm or less, preferably 2.3 μm or more and 5.0 μm or less, and more preferably 2.5 μm or more and 3.0 μm or less. Therefore, the handling of the hollow fiber membrane module 100 can be appropriately improved, and the adhesion of dirt to the outer surface 104b of the housing 104 can be appropriately suppressed.

[0067] Furthermore, in this hollow fiber membrane module 100, the first membrane bundle end 103b and the second membrane bundle end 103c of the hollow fiber membrane bundle 103 are fixed to the housing 104 by the first fixing part 108 and the second fixing part 109. The housing 104 has a first external space port 105c that opens into the external space S102 between the first fixing part 108 and the second fixing part 109, a second external space port 106a that communicates with the external space S102, an internal space port 107a that communicates with the internal space S101, and a baffle 105d positioned between the hollow fiber membrane bundle 103 and the first external space port 105c. Therefore, when liquid is supplied to the external space S102 from the second external space port 106a, the liquid passes between the multiple hollow fiber membranes 102, goes around the baffle 105d located between the hollow fiber membrane bundle 103 and the first external space port 105c, and is discharged from the first external space port 105c. At this time, the liquid supplied to the external space S102 can be degassed by sucking the internal space S101 from the internal space port 107a, and gas can be added to the liquid supplied to the external space S102 by supplying gas to the internal space S101 from the internal space port 107a.

[0068] In this case, when the hollow fiber membrane module 100 is used as an external perfusion type module, the liquid supplied to the external space S102 flows around the baffle 105d, which is positioned between the hollow fiber membrane bundle 103 and the first external space port 105c, and into the first external space port 105c. As a result, the hollow fiber membrane 102, which is in contact with the inner surface 105e of the baffle 105d, tends to oscillate greatly due to the force of the liquid flowing around the baffle 105d and into the first external space port 105c.

[0069] When a large flow rate of liquid is supplied to the external space S102, the force of the liquid flowing around the baffle 105d and into the first external space port 105c causes some of the hollow fiber membrane 102 to be strongly pressed against the inner surface 105e of the baffle 105d. Therefore, if the surface roughness Ra of the inner surface 105e of the baffle 105d is greater than the surface roughness Ra of the inner surfaces 104a of the housing 104 other than the baffle 105d, the friction between the hollow fiber membrane 102 and the baffle 105d causes the hollow fiber membrane 102 to adhere tightly to the inner surface 105e of the baffle 105d, suppressing the vibration of the hollow fiber membrane 102. This makes it possible to suppress a significant difference in the deterioration state of the hollow fiber membrane 102 between the portion that contacts the inner surface 105e of the baffle 105d and the portion that contacts the inner surface 104a of the housing 104 other than the baffle 105d when a large flow rate of liquid is supplied to the external space S102.

[0070] On the other hand, when a small flow rate of liquid is supplied to the external space S102, the force of the liquid flowing around the baffle 105d into the first external space port 105c prevents the hollow fiber membrane 102 from being strongly pressed against the inner surface 105e of the baffle 105d. As a result, the vibration of the hollow fiber membrane 102 in contact with the inner surface 105e of the baffle 105d increases. However, if the surface roughness Ra of the inner surface 105e of the baffle 105d is smaller than the surface roughness Ra of the inner surfaces 104a of the housing 104 other than the baffle 105d, the deterioration of the hollow fiber membrane 102 is suppressed even if it rubs against the inner surface 105e of the baffle 105d. This makes it possible to suppress a significant difference in the deterioration state of the hollow fiber membrane 102 between the portion that contacts the inner surface 105e of the baffle 105d and the portion that contacts the inner surface 104a of the housing 104 other than the baffle 105d when a small flow rate of liquid is supplied to the external space S102.

[0071] Furthermore, in this hollow fiber membrane module 100, in a cross-section perpendicular to the extending direction D of the hollow fiber membrane bundle 103 passing through the first membrane bundle end 103b, the region of the hollow fiber membrane bundle 103 other than the hollow portion 103a is sealed by the first fixing portion 108, and in a cross-section perpendicular to the extending direction D of the hollow fiber membrane bundle 103 passing through the second membrane bundle end 103c, the region of each of the multiple hollow fiber membranes 102 other than the hollow portion 102a is sealed by the second fixing portion 109. Therefore, the space in the housing 104 opposite to the first fixing portion 108 relative to the second fixing portion 109 becomes the internal space S101 (second end space S104), and the space opposite to the second fixing portion 109 relative to the first fixing portion 108 becomes the external space S102 (first end space S103). Furthermore, since the second external space port 106a opens into the external space S102 (first end space S103) on the opposite side of the second fixing part 109 to the first fixing part 108, the second external space port 106a can be connected to the hollow portion 103a of the hollow fiber membrane bundle 103. Also, since the internal space port 107a opens into the internal space S101 (second end space S104) on the opposite side of the first fixing part 108 to the second fixing part 109, the internal space port 107a can be connected to the hollow portions 102a of each of the multiple hollow fiber membranes 102.

[0072] [Degassing device] Figure 4 is a schematic diagram of a degassing device according to this embodiment. As shown in Figures 1 and 4, the degassing device 200 according to this embodiment comprises the hollow fiber membrane module 100 described above, a liquid supply pipe 201, a liquid discharge pipe 202, a suction pipe 203, and a suction device 204. The degassing device 200 is a device that degasses liquid L using the hollow fiber membrane module 100 as an external perfusion type hollow fiber membrane module.

[0073] The liquid supply pipe 201 is a pipe for supplying liquid L to the external space S102 through the second external space port 106a. The liquid supply pipe 201 is connected to the housing 104 and communicates with the second external space port 106a. The liquid supply pipe 201 may be fitted with a liquid supply device (not shown), such as a pump, to send the liquid L in the liquid supply pipe 201 to the hollow fiber membrane module 100 side. The liquid supply pipe 201 may also be fitted with a liquid supply device (not shown) to supply liquid L to the liquid supply pipe 201.

[0074] The liquid discharge pipe 202 is a pipe for discharging liquid L from the external space S102 through the first external space port 105c. The liquid discharge pipe 202 is connected to the housing 104 and communicates with the first external space port 105c. The liquid discharge pipe 202 may also be fitted with a liquid transfer device (not shown), such as a pump, to send the liquid L in the liquid discharge pipe 202 to the opposite side from the hollow fiber membrane module 100.

[0075] The suction tube 203 is a tube for drawing gas G from the internal space S101 through the internal space port 107a. The suction tube 203 is connected to the housing 104 and communicates with the internal space port 107a.

[0076] The suction device 204 is a device for aspirating gas G from the internal space S101 through the suction tube 203. The suction device 204 is connected to the suction tube 203 and sucks the internal space port 107a through the suction tube 203. As the suction device 204, for example, a vacuum pump, air pump, or suction device can be used.

[0077] Next, the operation of the degassing device 200 will be explained.

[0078] In the degassing device 200, the suction device 204 is activated to draw in the internal space S101 from the internal space port 107a. Liquid L is also supplied to the external space S102 from the second external space port 106a via the liquid supply pipe 201. The liquid L supplied to the external space S102 then flows around the multiple hollow fiber membranes 102, coming into contact with them. At this time, the internal space S101 is drawn in, causing the hollow portions 102a of each of the multiple hollow fiber membranes 102 to be under reduced pressure. Therefore, as the liquid L passes around the multiple hollow fiber membranes 102, dissolved gases, bubbles, and other gases G in the liquid L permeate through each of the multiple hollow fiber membranes 102 and move into the internal space S101. This results in the degassing of the liquid L. The degassed liquid L flows around the baffle 105d, passing through the inner space S105, the communication space S107, and the outer space S106, and is discharged from the first external space port 105c to the liquid discharge pipe 202. The gas G that has moved to the internal space S101 by permeating through each of the multiple hollow fiber membranes 102 is discharged from the internal space port 107a to the suction pipe 203.

[0079] Thus, in the degassing device 200 according to this embodiment, the liquid L supplied from the liquid supply pipe 201 to the second external space port 106a can be degassed by sucking the internal space port 107a through the suction pipe 203 using the suction device 204. Moreover, because it is equipped with the hollow fiber membrane module 100 described above, the liquid L can be degassed while simultaneously suppressing deterioration of the hollow fiber membrane 102, improving handling, and suppressing the adhesion of dirt.

[0080] [Air supply system] Figure 5 is a schematic diagram of the air supply device according to this embodiment. As shown in Figures 1 and 5, the air supply device 300 according to this embodiment comprises the hollow fiber membrane module 100 described above, a liquid supply pipe 301, a liquid discharge pipe 302, a gas supply pipe 303, and a gas supply device 304. The air supply device 300 is a device that adds gas G to liquid L using the hollow fiber membrane module 100 as an external perfusion type hollow fiber membrane module.

[0081] The liquid supply pipe 301 is a pipe for supplying liquid L to the external space S102 through the second external space port 106a. The liquid supply pipe 301 is connected to the housing 104 and communicates with the second external space port 106a. The liquid supply pipe 301 may be fitted with a liquid supply device (not shown), such as a pump, to send the liquid L in the liquid supply pipe 301 to the hollow fiber membrane module 100 side. The liquid supply pipe 301 may also be fitted with a liquid supply device (not shown) to supply liquid L to the liquid supply pipe 301.

[0082] The liquid discharge pipe 302 is a pipe for discharging liquid L from the external space S102 through the first external space port 105c. The liquid discharge pipe 302 is connected to the housing 104 and communicates with the first external space port 105c. The liquid discharge pipe 302 may also be fitted with a liquid transfer device (not shown), such as a pump, to send the liquid L in the liquid discharge pipe 302 to the opposite side from the hollow fiber membrane module 100.

[0083] The gas supply pipe 303 is a pipe for supplying gas G to the internal space S101 through the internal space port 107a. The gas supply pipe 303 is connected to the housing 104 and communicates with the internal space port 107a. The gas supply pipe 303 may be fitted with, for example, a diaphragm valve, a regulator, or other pressure regulating device (not shown) or flow rate regulating device (not shown) for regulating the pressure or flow rate of gas G flowing through the gas supply pipe 303.

[0084] The gas supply device 304 is a device for supplying gas G to the internal space S101 through the gas supply pipe 303. The gas supply device 304 is connected to the gas supply pipe 303 and supplies gas G to the internal space port 107a through the gas supply pipe 303. The gas supply device 304 can be configured, for example, with a gas cylinder filled with gas G and a gas delivery device that delivers gas G from the gas cylinder. As the gas delivery device, for example, a pump that delivers gas G by mechanical force, or a pressure delivery device that delivers gas G by air pressure can be used. If gas G is a gas that is a mixture of multiple gases, such as a mixed gas, multiple gas supply devices 304 may be provided, and the multiple gases delivered from the multiple gas supply devices 304 may be mixed, and this mixed gas may be supplied as gas G to the internal space S101 through the gas supply pipe 303.

[0085] Next, the operation of the air supply device 300 will be explained.

[0086] In the air supply device 300, the gas supply device 304 is activated to supply gas G to the internal space S101 from the internal space port 107a. In addition, liquid L is supplied to the external space S102 from the second external space port 106a through the liquid supply pipe 301. The liquid L supplied to the external space S102 then flows around the multiple hollow fiber membranes 102 and comes into contact with them. At this time, because gas G is supplied to the internal space S101, the hollow portions 102a of each of the multiple hollow fiber membranes 102 are pressurized by the gas G supplied to the internal space S101. Therefore, the gas G supplied to the internal space S101 moves to the external space S102 by passing through each of the multiple hollow fiber membranes 102. As a result, gas G is added to the liquid L passing around the multiple hollow fiber membranes 102. The liquid L to which gas G has been added flows around the baffle 105d, through the inner space S105, the communication space S107, and the outer space S106, and is discharged from the first external space port 105c to the liquid discharge pipe 302.

[0087] Thus, in the air supply device 300 according to this embodiment, gas G can be added to the liquid L supplied from the liquid supply pipe 301 to the second external space port 106a by supplying gas G to the internal space port 107a through the gas supply pipe 303 using the gas supply device 304. Moreover, because it is equipped with the hollow fiber membrane module 100 described above, gas G can be added to the liquid L while simultaneously suppressing deterioration of the hollow fiber membrane 102, improving handling, and suppressing the adhesion of dirt.

[0088] [Adjustment device] Figure 6 is a schematic diagram of the adjustment device according to the embodiment. As shown in Figures 1 and 6, the adjustment device 400 according to this embodiment comprises the hollow fiber membrane module 100 described above, a liquid supply pipe 401, a liquid discharge pipe 402, a gas supply pipe 403, a gas supply device 404, and a bypass pipe 405. The adjustment device 400 is a device that adjusts the dissolved concentration of gas G in liquid L by using the hollow fiber membrane module 100 as an external perfusion type hollow fiber membrane module.

[0089] The liquid supply pipe 401 is a pipe for supplying liquid L to the external space S102 through the second external space port 106a. The liquid supply pipe 401 is connected to the housing 104 and communicates with the second external space port 106a. The liquid supply pipe 401 may be fitted with a liquid supply device (not shown), such as a pump, to send the liquid L in the liquid supply pipe 401 to the hollow fiber membrane module 100 side. The liquid supply pipe 401 may also be fitted with a liquid supply device (not shown) to supply liquid L to the liquid supply pipe 401.

[0090] The liquid discharge pipe 402 is a pipe for discharging liquid L from the external space S102 through the first external space port 105c. The liquid discharge pipe 402 is connected to the housing 104 and communicates with the first external space port 105c. The liquid discharge pipe 402 may also be fitted with a liquid transfer device (not shown), such as a pump, to send the liquid L in the liquid discharge pipe 402 to the side opposite the hollow fiber membrane module 100.

[0091] The gas supply pipe 403 is a pipe for supplying gas G to the internal space S101 through the internal space port 107a. The gas supply pipe 403 is connected to the housing 104 and communicates with the internal space port 107a. The gas supply pipe 403 is fitted with a gas supply rate adjustment device 406, such as a diaphragm valve or regulator, for adjusting the pressure or flow rate of gas G flowing through the gas supply pipe 403.

[0092] The gas supply device 404 is a device for supplying gas G to the internal space S101 through the gas supply pipe 403. The gas supply device 404 is connected to the gas supply pipe 403 and supplies gas G to the internal space port 107a through the gas supply pipe 403. The gas supply device 404 can be configured, for example, with a gas cylinder filled with gas G and a gas delivery device that delivers gas G from the gas cylinder. As the gas delivery device, for example, a pump that delivers gas G by mechanical force, or a pressure delivery device that delivers gas G by air pressure can be used. If gas G is a gas that is a mixture of multiple gases, such as a mixed gas, multiple gas supply devices 404 may be provided, and the multiple gases delivered from the multiple gas supply devices 404 may be mixed, and this mixed gas may be supplied as gas G to the internal space S101 through the gas supply pipe 403.

[0093] The bypass pipe 405 is a pipe that allows the liquid to bypass the hollow fiber membrane module 100. The bypass pipe 405 is connected to the branch 407 of the liquid supply pipe 401 and the junction 408 of the liquid discharge pipe 402 so as to bypass the hollow fiber membrane module 100. The branch 407 is located at any position in the liquid supply pipe 401. The junction 408 is located at any position in the liquid discharge pipe 402.

[0094] The branching section 407 branches (distributes) the liquid L supplied to the liquid supply pipe 401 into two routes: one that flows to the liquid discharge pipe 402 via the hollow fiber membrane module 100, and another that bypasses the hollow fiber membrane module 100 and flows to the liquid discharge pipe 402.

[0095] The confluence section 408 combines the liquid L that has flowed through the hollow fiber membrane module 100 with the liquid L that has flowed bypassing the hollow fiber membrane module 100. In other words, the confluence section 408 combines the liquid L that has bypassed the hollow fiber membrane module 100 with the liquid L that has been discharged from the hollow fiber membrane module 100 to the liquid discharge pipe 402.

[0096] The bypass pipe 405 may be directly connected to the liquid supply pipe 401 at the branching section 407, or it may be indirectly connected to the liquid supply pipe 401 via other components such as a branching device. Furthermore, the bypass pipe 405 may be directly connected to the liquid discharge pipe 402 at the merging section 408, or it may be indirectly connected to the liquid discharge pipe 402 via other components such as a merging device.

[0097] The distribution ratio of liquid L at the branching section 407 can be adjusted by various known methods. For example, the distribution ratio of liquid L at the branching section 407 may be adjusted by adjusting the pressure loss of liquid L from the branching section 407 through the hollow fiber membrane module 100 to the confluence section 408, and the pressure loss of liquid L from the branching section 407 through the bypass pipe 405 to the confluence section 408. Alternatively, the distribution ratio of liquid L at the branching section 407 may be adjusted by installing a flow control valve 409 in at least one of the liquid supply pipe 401, liquid discharge pipe 402, and bypass pipe 405, and adjusting the opening degree of this flow control valve. In this embodiment, the flow control valve 409 is installed between the hollow fiber membrane module 100 of the liquid discharge pipe 402 and the confluence section 408.

[0098] Next, the operation of the adjustment device 400 will be explained.

[0099] The adjustment device 400 activates the gas supply device 404 to supply gas G to the internal space S101 from the internal space port 107a. Then, it supplies liquid L to the liquid supply pipe 401. At the branching section 407, the liquid L supplied to the liquid supply pipe 401 is divided into liquid L supplied to the hollow fiber membrane module 100 and liquid L that bypasses the hollow fiber membrane module 100.

[0100] The liquid L supplied to the hollow fiber membrane module 100 is supplied to the external space S102 through the second external space port 106a. The liquid L supplied to the external space S102 flows around the multiple hollow fiber membranes 102 and comes into contact with them. At this time, gas G is supplied to the internal space S101, so that the hollow portions 102a of each of the multiple hollow fiber membranes 102 are pressurized by the gas G supplied to the internal space S101. Therefore, the gas G supplied to the internal space S101 moves to the external space S102 by passing through each of the multiple hollow fiber membranes 102. As a result, gas G is added to the liquid L passing around the multiple hollow fiber membranes 102.

[0101] From the viewpoint of precisely adjusting the dissolved concentration of gas G in liquid L, it is preferable to adjust the supply amounts of liquid L and gas G in the hollow fiber membrane module 100 so that gas G is added (dissolved) in liquid L in a saturated state. The supply amount of liquid L can be adjusted, for example, by adjusting the flow control valve 409. The supply amount of gas G can be adjusted, for example, by adjusting the gas supply amount adjustment device 406.

[0102] The liquid L to which gas G has been added flows around the baffle 105d, through the inner space S105, the communication space S107, and the outer space S106, and is discharged from the first external space port 105c to the liquid discharge pipe 402. Then, at the confluence section 408, the liquid L that has bypassed the hollow fiber membrane module 100 is joined to the liquid L discharged from the first external space port 105c to the liquid discharge pipe 402. This results in a liquid L with an adjusted gas G dissolution concentration. The gas G dissolution concentration can be adjusted by adjusting the distribution ratio at the branching section 407, the supply amount of liquid L, and the supply amount of gas G.

[0103] As described above, in the adjustment device 400 according to this embodiment, the liquid L supplied to the liquid supply pipe 401 is distributed at the branching section 407 into liquid L supplied to the hollow fiber membrane module 100 and liquid L that bypasses the hollow fiber membrane module 100, and at the confluence section 408, the liquid L to which gas G has been added in the hollow fiber membrane module 100 and the liquid L that bypasses the hollow fiber membrane module 100 are combined. Therefore, by adjusting the distribution ratio at the branching section 407, the amount of liquid L supplied, the amount of gas G supplied, etc., the dissolved concentration of gas G in the liquid L supplied to the liquid supply pipe 401 can be adjusted. Moreover, because it is equipped with the hollow fiber membrane module 100 described above, the dissolved concentration of gas G in the liquid L can be adjusted while simultaneously suppressing deterioration of the hollow fiber membrane 102, improving handling, and suppressing the adhesion of dirt.

[0104] While preferred embodiments of this disclosure have been described above, this disclosure is not limited to the embodiments described above.

[0105] For example, although the configuration of the hollow fiber membrane module was specifically described in the above embodiment, the configuration of the hollow fiber membrane module can be changed as appropriate. For example, although the hollow fiber membrane bundle was described in the above embodiment as a bundle of multiple hollow fiber membranes in a cylindrical shape, the hollow fiber membrane bundle may simply be a bundle of multiple hollow fiber membranes.

[0106] Furthermore, as shown in the modified hollow fiber membrane module 100A in Figure 7, the hollow fiber membrane module may be equipped with an inner support that is positioned in the hollow portion of the hollow fiber membrane bundle and supports the hollow fiber membrane bundle from the inner circumferential side.

[0107] Figure 7 is a schematic cross-sectional view of a modified hollow fiber membrane module. The modified hollow fiber membrane module 100A shown in Figure 7 is basically the same as the hollow fiber membrane module 100 of the above embodiment, and differs from the hollow fiber membrane module 100 of the above embodiment in that it further comprises an inner support 110.

[0108] The inner support 110 is positioned in the hollow portion 103a of the hollow fiber membrane bundle 103 and is a member that supports the hollow fiber membrane bundle 103 from the inner circumference. The inner support 110 is formed in a cylindrical (pipe-like) shape. One end of the inner support 110 is fixed to the cylindrical portion 105 by a first fixing part 108, and the other end of the inner support 110 is fixed to the cylindrical portion 105 by a second fixing part 109. The outer diameter of the inner support 110 is approximately the same as the inner diameter of the hollow fiber membrane bundle 103. The thickness of the inner support 110 can be appropriately set within a range that can support, for example, a plurality of swollen hollow fiber membranes 102. The inner support 110 also has a plurality of openings. The inner support 110 is formed in a mesh-like shape, for example. Therefore, when liquid is supplied to the external space S102 from the second external space port 106a, the liquid comes into contact with the multiple hollow fiber membranes 102 through the hollow portion 110a of the inner support 110 and the opening of the inner support 110. The liquid, which has been degassed or gas added through contact with the multiple hollow fiber membranes 102, is then discharged to the outside of the hollow fiber membrane module 100 from the first external space port 105c, passing through the inner space S105, the communication space S107, and the outer space S106, as if circling around the baffle 105d.

[0109] Thus, in the modified hollow fiber membrane module 100A, the hollow fiber membrane bundle 103 is supported from the inner circumference by the inner support 110. Therefore, when multiple hollow fiber membranes 102 swell, it is possible to suppress the multiple hollow fiber membranes 102 from entering the hollow portion 103a of the hollow fiber membrane bundle 103 and narrowing or blocking the hollow portion 103a. This makes it possible to suppress an increase in the pressure loss of the liquid flowing through the hollow portion 103a of the hollow fiber membrane bundle 103.

[0110] Furthermore, as shown in the modified hollow fiber membrane module 100B in Figure 8, the hollow fiber membrane module may further include a mesh-like member that covers the bundle of hollow fiber membranes.

[0111] Figure 8 is a schematic cross-sectional view of a modified hollow fiber membrane module. The modified hollow fiber membrane module 100B shown in Figure 8 is basically the same as the hollow fiber membrane module 100 of the above embodiment, and differs from the hollow fiber membrane module 100 of the above embodiment in that it further comprises a mesh member 111.

[0112] The mesh member 111 is a mesh-like member that covers the hollow fiber membrane bundle 103. The mesh member 111 is a member that suppresses the separation of the multiple hollow fiber membranes 102 and reduces the contact area between the hollow fiber membranes 102 and the housing 104. The mesh member 111 is formed in a cylindrical (pipe-like) shape and has multiple mesh openings through which liquid can pass. The mesh member 111 is capable of expanding and contracting in the circumferential direction of the hollow fiber membrane bundle 103. Therefore, the mesh member 111 can deform its outer shape to follow the swelling of the multiple hollow fiber membranes.

[0113] As described above, in the modified hollow fiber membrane module 100B, the hollow fiber membrane bundle 103 is covered by a mesh member 111. Therefore, by positioning the mesh member 111 between the hollow fiber membrane bundle 103 and the housing 104, the contact area between the hollow fiber membrane 102 and the housing 104 can be reduced while ensuring the flow of liquid. This makes it possible to suppress the deterioration of the hollow fiber membrane 102 due to friction with the housing 104.

[0114] Furthermore, as shown in the modified hollow fiber membrane module 100C in Figure 9, the hollow fiber membrane module may have two ports that communicate with the internal space.

[0115] Figure 9 is a schematic cross-sectional view of a modified hollow fiber membrane module. The modified hollow fiber membrane module 100C shown in Figure 9 is basically the same as the modified hollow fiber membrane module 100A shown in Figure 7, but differs from the modified hollow fiber membrane module 100A shown in Figure 7 in that it has two ports that communicate with the internal space: a first internal space port and a second internal space port.

[0116] The hollow fiber membrane module 100C comprises a hollow fiber membrane bundle 103 in which a plurality of hollow fiber membranes 102 are bundled together in a cylindrical shape, an inner support 110 positioned in the hollow portion 103a of the hollow fiber membrane bundle 103 to support the hollow fiber membrane bundle 103 from the inner circumference, and a cylindrical housing 104C that houses the hollow fiber membrane bundle 103. The housing 104C comprises a cylindrical portion 105, a first lid portion 106C, and a second lid portion 107C. The first membrane bundle end 103b of the hollow fiber membrane bundle 103 is fixed to the first open end 105a of the cylindrical portion 105 by a first fixing portion 108C. The second membrane bundle end 103c of the hollow fiber membrane bundle 103 is fixed to the second open end 105b of the cylindrical portion 105 by a second fixing portion 109C.

[0117] The first fixing portion 108C seals the areas within the cylindrical portion 105 other than the hollow portions 102a of each of the multiple hollow fiber membranes 102 and the hollow portion 103a of the hollow fiber membrane bundle 103, in a cross section perpendicular to the extending direction D of the hollow fiber membrane bundle 103, passing through the first membrane bundle end 103b. In other words, the first fixing portion 108C fills the spaces between the multiple hollow fiber membranes 102 in the hollow fiber membrane bundle 103 and the space between the hollow fiber membrane bundle 103 and the cylindrical portion 105. The first fixing portion 108C has a communication opening 108Ca that opens the hollow portion 103a of the hollow fiber membrane bundle 103.

[0118] The second fixing portion 109C seals the areas within the cylindrical portion 105 other than the hollow portions 102a of each of the multiple hollow fiber membranes 102 and the hollow portion 103a of the hollow fiber membrane bundle 103, in a cross section perpendicular to the extending direction D of the hollow fiber membrane bundle 103, passing through the second membrane bundle end 103c. In other words, the second fixing portion 109C fills the spaces between the multiple hollow fiber membranes 102 in the hollow fiber membrane bundle 103 and the space between the hollow fiber membrane bundle 103 and the cylindrical portion 105. The second fixing portion 109C has a communication opening 109Ca that opens the hollow portion 103a of the hollow fiber membrane bundle 103.

[0119] The first lid portion 106C is airtightly joined to the first open end 105a of the cylindrical portion 105. Inside the first lid portion 106C, a first end space S103C is formed. The first end space S103C is It is part of the internal space S101, and each of the hollow portions 102a of the multiple hollow fiber membranes 102.It is connected to the first lid portion 106C, which has a second external space port 106Ca and a first internal space port 106Cb formed therein.

[0120] The second external space port 106Ca is in communication with the external space S102. Furthermore, the second external space port 106Ca connects the external space S102 to the outside of the hollow fiber membrane module 100C. The second external space port 106Ca extends in a pipe-like shape toward the inside of the housing 104C, is inserted into the communication opening 108Ca of the first fixing part 108C, and is connected to the end of the inner support 110. As a result, the second external space port 106Ca is in communication with the hollow portion 103a of the hollow fiber membrane bundle 103, enabling the supply of liquid to the hollow portion 103a of the hollow fiber membrane bundle 103.

[0121] The first internal space port 106Cb is in communication with the internal space S101. Furthermore, the first internal space port 106Cb connects each of the hollow portions 102a of the multiple hollow fiber membranes 102 to the outside of the hollow fiber membrane module 100C. The first internal space port 106Cb is formed in the first lid portion 106C and opens into the first end space S103C. That is, the first internal space port 106Cb opens into the internal space S101 on the opposite side of the second fixing portion 109C from the first fixing portion 108C.

[0122] The second lid portion 107C is airtightly joined to the second open end 105b of the cylindrical portion 105. Inside the second lid portion 107C, a second end space S104C is formed. The second end space S104C is part of the internal space S101 and is in communication with each of the hollow portions 102a of the multiple hollow fiber membranes 102. The second lid portion 107C has a boss portion 107Ca and a port 107Cb for the second internal space.

[0123] The boss portion 107Ca is the part that closes the communication opening 109Ca of the second fixing portion 109C. The boss portion 107Ca extends columnarly toward the inside of the housing 104C and is inserted into the communication opening 109Ca of the second fixing portion 109C, thereby closing the communication opening 109Ca of the second fixing portion 109C. The boss portion 107Ca is also referred to as a plug. The boss portion 107Ca prevents the liquid supplied to the hollow portion 103a of the hollow fiber membrane bundle 103 from being discharged into the second end space S104C. The boss portion 107Ca may be constructed separately from the second lid portion 107C.

[0124] The second internal space port 107Cb is in communication with the internal space S101. Furthermore, the second internal space port 107Cb connects each of the hollow portions 102a of the multiple hollow fiber membranes 102 to the outside of the hollow fiber membrane module 100C. The second internal space port 107Cb is formed in the second lid portion 107C and opens into the second end space S104C. That is, the second internal space port 107Cb opens into the internal space S101 on the opposite side of the first fixing portion 108C from the second fixing portion 109C.

[0125] Thus, in the modified hollow fiber membrane module 100C, there are two ports, a first internal space port 106Cb and a second internal space port 107Cb, which communicate with the internal space S101. Therefore, when the hollow fiber membrane module 100C is used as an external perfusion type module to add gas to a liquid, the gas in the internal space S101 can be replaced by supplying gas from either the first internal space port 106Cb or the second internal space port 107Cb and discharging the gas from the other of the two internal space ports 106Cb or the second internal space port 107Cb, thereby suppressing changes in the gas concentration in the internal space S101.

[0126] Furthermore, in the modified hollow fiber membrane module 100C shown in Figure 9, instead of the second lid having a boss portion, the second fixing portion may seal the hollow portion of the hollow fiber membrane bundle. Even with such a configuration, the same effects as the hollow fiber membrane module 100C can be achieved.

[0127] Furthermore, in the adjustment device 400 according to the above embodiment, a modified hollow fiber membrane module 100C shown in Figure 9 may be used instead of the hollow fiber membrane module 100, and a gas discharge pipe (not shown) may be further provided. In this case, the liquid supply pipe 401 may be connected to the second external space port 106Ca, the liquid discharge pipe 402 may be connected to the first external space port 105c, the gas supply pipe 403 may be connected to either the first internal space port 106Cb or the second internal space port 107Cb, and the gas discharge pipe may be connected to the other of either the first internal space port 106Cb or the second internal space port 107Cb. This makes it possible to adjust the dissolved concentration of gas G in liquid L with higher precision.

[0128] Furthermore, although the above embodiment describes the case in which the hollow fiber membrane module is used as an external perfusion type module, the hollow fiber membrane module may also be used as an internal perfusion type module. In this case, as shown in the modified hollow fiber membrane module 100C in Figure 9, a port communicating with the internal space may be formed in the housing, separate from the internal space port in the above embodiment, to supply liquid to the hollow portions of each of the multiple hollow fiber membranes. Various known hollow fiber membrane modules may be used as such a hollow fiber membrane module. [Explanation of symbols]

[0129] 100...Hollow fiber membrane module, 100A...Hollow fiber membrane module, 100B...Hollow fiber membrane module, 100C...Hollow fiber membrane module, 102...Hollow fiber membrane, 102a...Hollow section, 103...Hollow fiber membrane bundle, 103a...Hollow section, 103b...First membrane bundle end, 103c...Second membrane bundle end, 104...Housing, 104a...Inner surface, 104b...Outer surface, 104C...Housing, 105...Cylindrical section, 105a...First open end, 105b...Second open end, 105c ...First external space port, 105d...Baffle, 105e...Inner surface, 106...First lid, 106a...Second external space port, 106C...First lid, 106Ca...Second external space port, 106Cb...First internal space port, 107...Second lid, 107a...Internal space port, 107C...Second lid, 107Ca...Boss, 107Cb...Second internal space port, 108...First fixing part, 108a...Communication opening, 108C...First fixing part, 108C a...Communication port, 109...Second fixing part, 109C...Second fixing part, 109Ca...Communication port, 110...Inner support, 110a...Hollow part, 111...Mesh member, 200...Degassing device, 201...Liquid supply pipe, 202...Liquid discharge pipe, 203...Suction pipe, 204...Suction device, 300...Air supply device, 301...Liquid supply pipe, 302...Liquid discharge pipe, 303...Gas supply pipe, 304...Gas supply device, 400...Adjustment device, 401...Liquid supply pipe, 402...Liquid discharge pipe, 403... Gas supply pipe, 404... Gas supply device, 405... Bypass pipe, 406... Gas supply amount adjustment device, 407... Branch section, 408... Junction section, 409... Flow control valve, A... Central axis, B... Central axis, D... Extension direction, G... Gas, L... Liquid, S101... Internal space, S102... External space, S103... First end space, S103C... First end space, S104... Second end space, S104C... Second end space, S105... Inner space, S106... Outer space, S107... Communication space.

Claims

1. A bundle of multiple hollow fiber membranes, The system comprises a housing for accommodating the aforementioned hollow fiber membrane bundle, The space within the housing is divided by the plurality of hollow fiber membranes into an internal space including the hollow portion of each of the plurality of hollow fiber membranes and an external space not including the hollow portion of each of the plurality of hollow fiber membranes, The surface roughness Ra of the inner surface of the housing is 0.1 μm or more and less than 2.0 μm. The surface roughness Ra of the inner surface of the housing is smaller than the surface roughness Ra of the outer surface of the housing. Hollow fiber membrane module.

2. The surface roughness Ra of the outer surface of the housing is 2.0 μm or more and 10 μm or less. The hollow fiber membrane module according to claim 1.

3. A first fixing part that fixes the first membrane bundle end, which is one end of the hollow fiber membrane bundle, to the housing, The system further includes a second fixing part for fixing the second membrane bundle end, which is the other end of the hollow fiber membrane bundle, to the housing, The housing includes a first external space port opening into the external space between the first fixed portion and the second fixed portion, a second external space port communicating with the external space, an internal space port communicating with the internal space, and a baffle positioned between the hollow fiber membrane bundle and the first external space port. The hollow fiber membrane module according to claim 1.

4. The surface roughness Ra of the inner surface of the baffle on the side opposite to the first external space port is greater than the surface roughness Ra of the inner surface of the housing other than the baffle. The hollow fiber membrane module according to claim 3.

5. The surface roughness Ra of the inner surface of the baffle on the side opposite to the first external space port is smaller than the surface roughness Ra of the inner surface of the housing other than the baffle. The hollow fiber membrane module according to claim 3.

6. The first fixing portion seals the region of the hollow fiber membrane bundle other than the hollow portion in a cross-section perpendicular to the direction of extension of the hollow fiber membrane bundle, passing through the end of the first membrane bundle. The second fixing portion seals the regions of each of the plurality of hollow fiber membranes other than the hollow portion in a cross-section that passes through the end of the second membrane bundle and is perpendicular to the extending direction of the hollow fiber membrane bundle, The second external space port opens to the external space on the side opposite to the second fixed part relative to the first fixed part, The port for the internal space opens to the internal space on the side of the second fixing part that is opposite to the first fixing part. The hollow fiber membrane module according to claim 3.

7. The housing further has a port for a second internal space that communicates with the internal space. The hollow fiber membrane module according to claim 3.

8. The hollow fiber membrane bundle is further provided with an inner support which is disposed in the hollow portion and supports the hollow fiber membrane bundle from the inner circumferential side. The hollow fiber membrane module according to claim 3.

9. The system further comprises a mesh-like member covering the hollow fiber membrane bundle. The hollow fiber membrane module according to claim 3.

10. A hollow fiber membrane module according to any one of claims 3 to 9, A liquid supply pipe connected to the second external space port, A suction pipe that communicates with the aforementioned internal space port, The system includes a suction device that sucks the internal space port through the suction tube, Degassing device.

11. A hollow fiber membrane module according to any one of claims 3 to 9, A liquid supply pipe connected to the second external space port, A gas supply pipe connected to the aforementioned internal space port, The system includes a gas supply device that supplies gas to the internal space port through the gas supply pipe. Air supply device.

12. A hollow fiber membrane module according to any one of claims 3 to 9, A liquid supply pipe connected to the second external space port, A liquid discharge pipe connected to the first external space port, A gas supply pipe connected to the aforementioned internal space port, A gas supply device that supplies gas to the internal space port through the gas supply pipe, The system includes a bypass pipe that communicates with the branch of the liquid supply pipe and the junction of the liquid discharge pipe so as to bypass the hollow fiber membrane module. Adjustment device.

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