Hollow fiber membrane module

Abstract

Provided is a hollow fiber membrane module capable of inhibiting breakage of a hollow fiber membrane. A hollow fiber membrane module in which both ends of a bundle of hollow fiber membranes are housed in a housing via a bonded fixing portion, wherein, on an end surface of the bonded fixing portion at which the hollow fiber membranes are opened, a point corresponding to a portion on an outer peripheral surface of the bonded fixing portion having a smallest thickness is taken as an upper vertex, and when a horizontal line that is orthogonal to a perpendicular line from the upper vertex toward a center of the end surface and that passes through the center is drawn, a number of the hollow fiber membranes on an upper side of the horizontal line / a number of the hollow fiber membranes on a lower side is 0.9 to 1.1.

Description

Technical Field

[0001] This invention relates to a hollow fiber membrane module. Background Technology

[0002] Generally, hollow fiber membrane modules are broadly classified into internal pressure type and external pressure type. External pressure type hollow fiber membrane modules typically have both ends of their cylindrical shell sealed with potting material (adhesive), and the hollow fiber membrane bundles at both ends are bonded and fixed within the shell using this potting material. External pressure type hollow fiber membrane modules include single-end water collection modules (where one end of the hollow fiber membrane is sealed and the other end is open) and double-end water collection modules (where both ends of the hollow fiber membrane are open).

[0003] In the manufacture of hollow fiber membrane modules, centrifugal bonding is used, for example. In centrifugal bonding, a cylindrical shell is placed horizontally and rotated, using centrifugal force to cure the potting compound at both ends of the shell. Therefore, when the filler content of the hollow fiber membrane is low, the hollow fiber membrane is bonded and fixed in a biased position under the action of gravity.

[0004] When using external pressure hollow fiber membrane modules for sterilization or turbidity removal, regular backwashing or air washing is required to restore filtration performance in order to ensure stable filtration operation. During such air washing, if the density distribution of the hollow fiber membrane inside the housing is uneven, the hollow fiber membrane is prone to breakage due to large-scale oscillations.

[0005] Therefore, in order to prevent the density distribution deviation of the hollow fiber membrane, for example, patent documents 1 and 2 describe a hollow fiber membrane assembly in which a cross-shaped or rod-shaped limiting member is provided at the end of the hollow fiber membrane bundle to prevent the density distribution deviation of the hollow fiber membrane and is then bonded and fixed.

[0006] Existing technical documents

[0007] Patent documents

[0008] Patent Document 1: Japanese Patent Application Publication No. 2015-131267

[0009] Patent Document 2: Japanese Patent Application Publication No. 2000-185220 Summary of the Invention

[0010] The problem to be solved by the present invention

[0011] However, since hollow fiber membranes cannot be placed in the locations where restrictive components are configured, there is a problem that there are parts with relatively high density and parts with low density of hollow fiber membranes inside the shell.

[0012] The present invention was made in view of the above circumstances, and its object is to provide a hollow fiber membrane assembly that can prevent the density distribution deviation of the hollow fiber membrane inside the housing and can suppress the breakage of the hollow fiber membrane.

[0013] means for solving problems

[0014] The main points of this invention are as follows.

[0015] [1] A hollow fiber membrane module, the hollow fiber membrane module comprising: a cylindrical shell, a hollow fiber membrane bundle formed by bundling multiple hollow fiber membranes, a first bonding and fixing part, and a second bonding and fixing part, wherein,

[0016] The two ends of the hollow fiber membrane bundle are respectively housed in the cylindrical shell via the first bonding and fixing part and the second bonding and fixing part;

[0017] The first adhesive fixing part and the second adhesive fixing part have generally circular end faces that are perpendicular to the length direction of the shell, and the hollow portions of the plurality of hollow fiber membranes are open on at least one of the end faces.

[0018] In the first and / or second adhesive fixing portions of the end face having the hollow opening of the hollow fiber membrane, the region between the outer surface of the plurality of hollow fiber membranes and the inner surface of the housing, without the presence of restricting members that restrict the bias of the plurality of hollow fiber membranes, is filled with adhesive resin of a predetermined thickness in the length direction, and the hollow fiber membrane bundle is bonded and fixed to the housing.

[0019] On the end face of the hollow opening of the hollow fiber membrane, the point corresponding to the portion with the smallest thickness in the length direction on the outer peripheral surface of the adhesive fixing portion having the end face is taken as the upper vertex. When drawing a horizontal line that is orthogonal to the perpendicular line from the upper vertex toward the center of the end face and passes through the center, the ratio of the number of hollow fiber membranes above the horizontal line to the number of hollow fiber membranes below the horizontal line (number of hollow fiber membranes above the horizontal line) / (number of hollow fiber membranes below the horizontal line) is 0.9 or more and 1.1 or less.

[0020] [2] According to the hollow fiber membrane assembly of Project 1, wherein, on the end face of the hollow portion opening of the hollow fiber membrane of the first bonding and / or the second bonding and fixing portion, a first circle is defined as a circle with the smallest diameter including all hollow fiber membranes present on the end face, a second circle is concentric with the first circle and has a diameter 2 cm smaller than the first circle, a first square is defined as the largest of the squares located in the center of the second circle with a side length of N cm (where N is a natural number), and an N square is defined by dividing the first square into 1 cm squares. 2When there are two second squares, the ratio of the minimum number of hollow fiber membranes contained in each second square to the maximum number of hollow fiber membranes is 0.4 or higher.

[0021] [3] The hollow fiber membrane assembly according to item 1 or 2, wherein the diameter of the end face of the hollow portion opening of the hollow fiber membrane is 150 mm or more.

[0022] [4] The hollow fiber membrane assembly according to any one of items 1 to 3, wherein, (the average of the thickness L1 of the adhesive fixing portion at one intersection of the outer peripheral surface and the horizontal line and the thickness L2 of the adhesive fixing portion at another intersection of the outer peripheral surface and the horizontal line) - (the thickness L of the adhesive fixing portion at the center of the end face) О The value is 1mm or more and 12mm or less, and,

[0023] The thickness L4 of the adhesive fixing part at the intersection of the perpendicular line from the upper vertex toward the center of the end face and the other point of the outer peripheral surface is 3 mm or more and 12 mm or less.

[0024] [5] The hollow fiber membrane assembly according to any one of items 1 to 4, wherein the total length of the shell is 1 m or more.

[0025] [6] The hollow fiber membrane assembly according to any one of items 1 to 5, wherein the total cross-sectional area of ​​all hollow fiber membranes / the internal cross-sectional area of ​​the shell, i.e. the filling rate of the hollow fiber membrane on the end face of the hollow part opening of the hollow fiber membrane, is 10% or more and 45% or less.

[0026] [7] According to the hollow fiber membrane assembly described in Project 6, the total cross-sectional area of ​​all hollow fiber membranes / the internal cross-sectional area of ​​the shell, i.e. the filling rate of the hollow fiber membrane on the end face of the hollow part opening of the hollow fiber membrane, is 25% or more.

[0027] [8] The hollow fiber membrane assembly according to any one of items 1 to 7, wherein the resin constituting the first adhesive fixing part and / or the second adhesive fixing part of the end face having the hollow part opening of the hollow fiber membrane is a single thermosetting resin with a D hardness of 60 or less at 25°C according to JIS K7215.

[0028] [9] According to the hollow fiber membrane module of Project 8, wherein the single thermosetting resin is a two-component curable thermosetting resin, wherein the viscosity of the thermosetting resin is 1 Pa·s or more and 10 Pa·s or less after 10 minutes from the start of two-component mixing, and the viscosity after 30 minutes exceeds 100 Pa·s.

[0029]

[10] A hollow fiber membrane assembly according to any one of items 1 to 9, wherein the plurality of hollow fiber membranes are made of fluororesin.

[0030]

[11] In the hollow fiber membrane assembly according to any one of items 1 to 10, on the virtual bonding interface where the end face of the hollow portion opening of the hollow fiber membrane is virtually moved parallel to the center in the longitudinal direction towards the outer peripheral surface of the first bonding fixing part and / or the second bonding fixing part, the thickness of the portion with the smallest thickness in the longitudinal direction is 20% or more and 50% or less, and on the virtual bonding interface, taking the point corresponding to the portion with the smallest thickness in the longitudinal direction on the outer peripheral surface as the upper vertex, when drawing a horizontal line that is orthogonal to the perpendicular line from the upper vertex toward the center of the virtual bonding interface and passes through the center, the ratio of the number of hollow fiber membranes above the horizontal line to the number of hollow fiber membranes below the horizontal line (number of hollow fiber membranes above the horizontal line) / (number of hollow fiber membranes below the horizontal line) is 0.85 or more and 1.15 or less.

[0031] Invention Effects

[0032] According to the present invention, a hollow fiber membrane assembly capable of preventing deviations in the density distribution of the hollow fiber membrane inside the housing and suppressing the breakage of the hollow fiber membrane can be obtained. Attached Figure Description

[0033] [ Figure 1 [A diagram showing a schematic structure of one embodiment of the hollow fiber membrane module 1 of the present invention]

[0034] [ Figure 2 ]Will Figure 1 Enlarged cross-sectional view of the upper part of the hollow fiber membrane module 1 shown.

[0035] [ Figure 3 ] Figure 1 The cross-sectional view of the hollow fiber membrane module 1 along line CD shown.

[0036] [ Figure 4 A schematic diagram showing the appearance of the protective member 8 disposed inside the housing 5.

[0037] [ Figure 5 [Schematic diagram illustrating the protrusion 50 of the hollow fiber membrane 2]

[0038] [ Figure 6 ] Observe from the direction of arrow A Figure 1 and Figure 2 A schematic diagram of the end face 21a of the second adhesive fixing part 21 of the hollow fiber membrane assembly 1 shown.

[0039] [ Figure 7 A schematic diagram showing a section of the interior of the housing 5 to illustrate the location of the virtual bonding interface S'.

[0040] [ Figure 8 ] Observe from the direction of arrow A Figure 1 and Figure 2 A schematic diagram of the end face 21a of the second adhesive fixing part 21 of the hollow fiber membrane assembly 1 shown.

[0041] [ Figure 9 A schematic diagram showing a cross-section of a portion inside the housing 5 to illustrate the shape of the interface of the second adhesive fixing part 21.

[0042] [ Figure 10 A schematic diagram showing the end face of the second adhesive fixing part of the hollow fiber membrane module of Comparative Example 1 is shown. Detailed Implementation

[0043] The following describes in detail an exemplary mode for carrying out the present invention (hereinafter also referred to as this embodiment). Furthermore, the present invention is not limited to the embodiments described below, and various modifications and uses are possible within the scope of its indicated intent. In the accompanying drawings, the dimensions of the elements are appropriately emphasized for illustrative purposes.

[0044] Structure of Hollow Fiber Membrane Module 1

[0045] The hollow fiber membrane module 1 of this embodiment will now be described with reference to the accompanying drawings. The hollow fiber membrane module 1 of this embodiment is used in various fields such as water supply and drainage systems, food industry, general industry, medical applications, and physical and chemical processes. Figure 1 This is a diagram illustrating a schematic structure of the hollow fiber membrane module 1 according to this embodiment; Figure 2 It is Figure 1 An enlarged cross-sectional view of a portion of the hollow fiber membrane module 1 is shown. Additionally, in Figure 1 In the text, the up and down directions are represented by arrows: upward (T) and downward (B). Furthermore, the following will... Figure 1 The vertical direction shown is used to describe the vertical direction of the hollow fiber membrane module 1.

[0046] Figure 1 An embodiment of an externally pressurized hollow fiber membrane module is shown, but this embodiment can also be used as an internally pressurized hollow fiber membrane module.

[0047] like Figure 1As shown, the hollow fiber membrane assembly 1 of this embodiment schematically includes a cylindrical shell 5, a hollow fiber membrane bundle 3 formed by bundling multiple hollow fiber membranes 2, a first bonding and fixing part 20, and a second bonding and fixing part 21. The two ends of the hollow fiber membrane bundle 3 are respectively housed within the cylindrical shell 5 via the first bonding and fixing part 20 and the second bonding and fixing part 21. The hollow fiber membrane assembly 1 of this embodiment can also be vertically arranged with its length direction being vertical.

[0048] The overall length of the housing 5 is preferably 1m or more, more preferably 1.5m or more and 2.5m or less. This allows for space-saving design of the water treatment equipment while increasing the filtration flow rate of the hollow fiber membrane module 1.

[0049] <Shell 5>

[0050] The generally cylindrical housing 5 is constructed by joining together a first cylindrical member 51 located at the lower part of the housing 5, a second cylindrical member 52 located at the upper part of the housing 5 and integrally formed with a nozzle 52a, and a straight tubular third cylindrical member 53 disposed between the first cylindrical member 51 and the second cylindrical member 52. The nozzle 52a is provided on the side of the second cylindrical member 52 and is provided in a manner that protrudes in a direction orthogonal to the length direction of the housing 5.

[0051] At the two ends of the housing 5, there are hollow cone-shaped pipe connection caps 10 and 11, which are formed with pipes 10a and 11a for connecting pipes. The pipe connection caps 10 and 11 are fixedly installed on the housing 5 by clamps 13.

[0052] In the external pressure filtration process of this embodiment, the water to be treated (the liquid to be treated) is supplied from the pipe 10a of the cover 10 into the hollow fiber membrane module 1, and the filtered water is discharged from the cover 11 through the pipe 11a and the concentrated water through the nozzle 52a to the outside of the hollow fiber membrane module 1. Alternatively, the housing 5 may further have a nozzle (not shown) on the side of the first cylindrical member 51, through which the water to be treated (the liquid to be treated) can be supplied to the hollow fiber membrane module 1.

[0053] An annular groove is formed on the end face of the housing 5 side of the cover 10 and 11 and on the end face of the cover 10 and 11 side of the housing 5, and an annular sanitary gasket 12 is clamped by the groove. The sanitary gasket 12 seals the two ends of the housing 5 with the cover 10 and 11 to prevent water leakage from the hollow fiber membrane assembly 1.

[0054] Hollow fiber membrane bundles

[0055] The hollow fiber membrane bundle 3 is housed within the housing 5, extending along its entire length. The hollow fiber membrane bundle 3 is formed by binding together multiple hollow fiber membranes 2, each having a long, hollow cylindrical shape. The lengths of the hollow fiber membranes 2 constituting the hollow fiber membrane bundle 3 need not all be identical, but are preferably of a certain length. Through the hollow fiber membrane bundle 3, the internal space of the housing 5 is divided into an inner region and an outer region 5b, which are the hollow portions of the hollow fiber membranes 2.

[0056] The hollow fiber membrane 2 preferably has an inner diameter of 50 μm or more and 3000 μm or less, more preferably 500 μm or more and 2000 μm or less. Furthermore, it is preferable to use a hollow fiber membrane with an inner diameter to outer diameter ratio of 0.3 or more and 0.8 or less.

[0057] As the hollow fiber membrane 2, reverse osmosis membranes, nanofiltration membranes, ultrafiltration membranes, and microfiltration membranes can be used. There are no particular limitations on the raw materials for the hollow fiber membrane 2; examples include polysulfone, polyethersulfone, polyacrylonitrile, polyimide, polyetherimide, polyamide, polyetherketone, polyetheretherketone, polyethylene, polypropylene, poly(4-methylpentene), ethylene-vinyl alcohol copolymer, cellulose, cellulose acetate, polyvinylidene fluoride, ethylene-tetrafluoroethylene copolymer, and polytetrafluoroethylene, etc. Additionally, composite raw materials of these materials can also be used.

[0058] In one embodiment, the multiple hollow fiber membranes 2 are made of fluororesin, more preferably of polyvinylidene fluoride. This improves the ease of cleaning and durability of the hollow fiber membranes 2.

[0059] <First adhesive fixing part 20 and second adhesive fixing part 21>

[0060] At both ends of the hollow fiber membrane bundle 3, there are generally cylindrical first bonding and fixing portions 20 and second bonding and fixing portions 21, which are used to bond and fix the hollow fiber membranes 2 to each other and to bond and fix the hollow fiber membrane bundle 3 to the inner wall of the shell 5. The first bonding and fixing portions 20 and the second bonding and fixing portions 21 have generally circular end faces that are perpendicular to the length direction of the shell 5, and on at least one end face, the hollow portions of multiple hollow fiber membranes 2 are open.

[0061] In the hollow fiber membrane assembly 1 of this embodiment, in the bonding and fixing portions 20 and / or bonding and fixing portions 21 at the end faces having hollow openings of the hollow fiber membranes 2, the area between the outer surfaces of the plurality of hollow fiber membranes 2 and the inner surface of the housing 5, without the presence of restricting members that restrict the bias of the plurality of hollow fiber membranes 2, is filled with adhesive resin in the longitudinal direction to a predetermined thickness, and the hollow fiber membrane bundle 3 is bonded and fixed to the housing 5 in a liquid-tight state. Hereinafter, the term "bonding and fixing portion thickness" will equally refer to the thickness of the first bonding and fixing portion 20 and the second bonding and fixing portion 21 in the longitudinal direction of the hollow fiber membrane assembly 1.

[0062] By providing limiting members (e.g., described later) within the adhesive fixing portion 20 and / or adhesive fixing portion 21 at the end face that does not have an opening in the hollow portion of the hollow fiber membrane 2. Figure 10 (Similar to the limiting member 41), the hollow fiber membrane 2 can be uniformly disposed on this end face. As a result, the density distribution of the hollow fiber membrane 2 can be made uniform on the end face of at least one of the first adhesive fixing part 20 and the second adhesive fixing part 21, resulting in a more uniform density distribution of the hollow fiber membrane 2 within the housing 5.

[0063] In one implementation scheme, such as Figure 1 and Figure 2 As shown, in the second adhesive fixing part 21, the upper end of the hollow fiber membrane bundle 3 is open, and the inner region of the hollow fiber membrane 2 leads to the conduit 11a of the cover 11. On the other hand, the lower end of the hollow fiber membrane bundle 3 is sealed by the first adhesive fixing part 20. In other embodiments, the lower end of the hollow fiber membrane bundle 3 may be open and the upper end sealed, or both ends of the hollow fiber membrane bundle 3 may be open.

[0064] In this implementation plan, such as Figure 1 As shown, a plurality of through holes 20a are formed on the first adhesive fixing part 20. The through holes 20a are formed parallel to the length direction of the housing 5 and are holes that connect the outer region 5b to the outer region 5c on the opposite side of the first adhesive fixing part 20. During filtration, the water to be treated (the liquid to be treated) flows in from the pipe 10a of the cover 10 provided on the outside of the first adhesive fixing part 20, and the water to be treated is supplied to the outer region 5b through the through holes 20a.

[0065] Figure 3 yes Figure 1 The diagram shows a cross-sectional view along line CD of the hollow fiber membrane module 1. In this embodiment, as... Figure 3 As shown, a plurality of through holes 20a are formed and uniformly distributed within the first adhesive fixing portion 20. It should be noted that while it is desirable for the through holes 20a to be uniformly distributed within the first adhesive fixing portion 20 as in this embodiment, it is not limited to this and other configurations are also possible. Furthermore, in another embodiment, if the lower end of the hollow fiber membrane bundle 3 is open, the first adhesive fixing portion 20 may not have through holes 20a formed.

[0066] As the potting material constituting the first adhesive fixing part 20 and the second adhesive fixing part 21, epoxy resin, vinyl ester resin, polyurethane resin, unsaturated polyester resin, olefin polymer, silicone resin and fluorinated resin are preferred polymer materials. Any one of these polymer materials can be used, or a combination of multiple polymer materials can be used.

[0067] <Annular protrusion and concavity 5a>

[0068] like Figure 1 and Figure 2 As shown, the hollow fiber membrane assembly 1 of this embodiment has annular protrusions and concavities 5a on the inner walls of both ends of the housing 5. The annular protrusions and concavities 5a form annular protrusions and concavities on the sides of the first bonding and fixing portion 20 and the second bonding and fixing portion 21. This increases the bonding area between the housing 5 and the first bonding and fixing portion 20 and the second bonding and fixing portion 21, resulting in higher bonding strength.

[0069] <Rectifier 7>

[0070] like Figure 1 and Figure 2 As shown, the hollow fiber membrane assembly 1 of this embodiment has a cylindrical rectifying cylinder 7 located on the outer periphery of the upper end (nozzle 52a side) of the hollow fiber membrane bundle 3. The rectifying cylinder 7 is disposed between the opening on the inner wall side of the housing 5 of the nozzle 52a and the hollow fiber membrane bundle 3, and is arranged to surround the outer periphery of the hollow fiber membrane bundle 3. The rectifying cylinder 7 ensures the spacing between the hollow fiber membrane bundle 3 and the inner wall of the housing 5 near the nozzle 52a. As a result, when concentrated water is discharged from the nozzle 52a, the hollow fiber membrane 2 can be prevented from swinging towards the nozzle 52a side, and the breakage of the hollow fiber membrane 2 can be prevented. Alternatively, the rectifying cylinder 7 may also be disposed on the outer periphery of the lower end of the hollow fiber membrane bundle 3.

[0071] like Figure 1 As shown, the rectifier cylinder 7 has a drain-shaped cylindrical wall surface with multiple through holes 30. It is desirable that the through holes 30 of the rectifier cylinder 7 be formed in a region other than the area opposite the opening on the inner side of the housing 5 of the nozzle 52a, and not in the area opposite the opening. This allows for control of water flow and improves the effect of preventing the hollow fiber membrane 2 from swaying towards the nozzle 52a.

[0072] The rectifier tube 7 includes a flange 7a at the central end of the hollow fiber membrane assembly 1. The flange 7a is clamped by the joint of the second cylindrical member 52 and the third cylindrical member 53, thereby fixing the rectifier tube 7 between the hollow fiber membrane bundle 3 and the inner wall of the housing 5. The other end of the rectifier tube 7 is bonded and fixed in the second adhesive fixing part 21 described above.

[0073] <Protective Component 8>

[0074] Figure 4 The appearance of the protective member 8 disposed within the housing 5 is shown. In one embodiment, the hollow fiber membrane assembly 1 may also include a cylindrical protective member 8 covering the outer peripheral surface of the hollow fiber membrane bundle 3. Additionally, in Figure 4 In the middle, the following was omitted. Figure 1 The illustration shows the hollow fiber membrane bundle 3 and the rectifier cylinder 7. Furthermore, in Figure 1 The illustration of protective component 8 is omitted in the text.

[0075] The protective member 8 is a flexible member formed by shaping the mesh into a cylindrical shape. The material used for the mesh protective member 8 is preferably a heat-resistant material such as PFA (tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer), FEP (tetrafluoroethylene-hexafluoropropylene copolymer (4-6 fluorinated)), ETFE (tetrafluoroethylene-ethylene copolymer), PTFE (polytetrafluoroethylene (4 fluorinated), polysulfone, etc.

[0076] The two ends of the protective component 8 are located in the first adhesive fixing part 20 and the second adhesive fixing part 21, respectively, and are bonded to the inner wall of the housing 5 through the first adhesive fixing part 20 and the second adhesive fixing part 21.

[0077] During the external pressure filtration process, the water to be treated, supplied to the outer region 5b, permeates through the protective member 8 and then seeps into the outer surface of each hollow fiber membrane 2. The filtered water that has passed through the hollow part of each hollow fiber membrane 2 is discharged from the pipe 11a of the cover 11, and the concentrated water is discharged from the nozzle 52a.

[0078] Cleaning and Treatment

[0079] In the hollow fiber membrane module 1 of this embodiment, after the external pressure filtration process as described above, a periodic air-washing cleaning process is performed. Specifically, washing water is supplied from the upper second bonding and fixing part 21 side, while air is supplied from the through hole 20a of the lower first bonding and fixing part 20. The two supplied fluids are discharged from the nozzle 52a of the second cylindrical member 52, thereby shaking the hollow fiber membrane 2 to remove dirt adhering to the membrane surface.

[0080] The end face of the hollow section opening of hollow fiber membrane 2

[0081] As described above, the first adhesive fixing part 20 and / or the second adhesive fixing part 21 have a generally circular end face with an opening in the hollow portion of the hollow fiber membrane 2. Here, "generally circular" means that the shape includes not only a perfect circle but also an ellipse. When the end face is an ellipse, the diameter of the end face refers to the minor axis of the ellipse. The diameter of the end face is consistent with the inner diameter of the end on the surface perpendicular to the length direction of the housing 5.

[0082] In one implementation scheme, such as Figure 2 As shown, the hollow portion of the hollow fiber membrane 2 opens on the end face 21a of the second bonding and fixing portion 21. In another embodiment, the hollow portion of the hollow fiber membrane 2 may open on the end face of the first bonding and fixing portion 20, or the hollow portion of the hollow fiber membrane 2 may open at both the first bonding and fixing portion 20 and the second bonding and fixing portion 21.

[0083] <Diameter>

[0084] The diameter of the opening end face of the hollow portion of the hollow fiber membrane 2 is preferably 50 mm or more, or 100 mm or more, or 150 mm or more, or 165 mm or more; and preferably 300 mm or less or 250 mm or less. This allows for space-saving installation of the water treatment equipment while uniformly injecting the potting material into the required areas inside the housing 5.

[0085] <Fill Rate>

[0086] In one embodiment, the total cross-sectional area of ​​all hollow fiber membranes 2 (ratio of the total cross-sectional area of ​​the shell 5), i.e., the filling rate of the hollow fiber membrane 2 on the end face of the hollow portion opening of the hollow fiber membrane 2, is preferably 45% or less or 40% or less. This allows for the formation of appropriate gaps between the hollow fiber membranes 2 and enables the uniform injection of potting material into the desired areas inside the shell 5.

[0087] Furthermore, the filling rate of the hollow fiber membrane 2 at the end face of the hollow portion opening (total cross-sectional area of ​​all hollow fiber membranes 2 / internal cross-sectional area of ​​the shell 5) is preferably 10% or more, or 25% or more, or 30% or more. This reduces the proportion of potting material in the adhesive fixing portion 20 and / or adhesive fixing portion 21, thereby suppressing cracking and peeling at the adhesive fixing portion 20 and / or adhesive fixing portion 21 due to curing shrinkage.

[0088] Furthermore, the cross-sectional area of ​​all the hollow fiber membranes 2 mentioned above is defined as the cross-sectional area including the hollow portion of the hollow fiber membrane 2. The total cross-sectional area of ​​all the hollow fiber membranes 2 is the product of the cross-sectional area of ​​each hollow fiber membrane 2 and the number of hollow fiber membranes 2. The fill rate can be calculated by dividing this total cross-sectional area by the internal cross-sectional area of ​​the shell 5.

[0089] <Resin material forming the end face of the hollow section opening>

[0090] The resin (potting material) constituting the first adhesive fixing portion 20 and / or the second adhesive fixing portion 21 at the end face of the hollow portion opening of the hollow fiber membrane 2 is preferably a single thermosetting resin with a D hardness of 60 or less at 25°C according to JIS K7215. By using a single resin, there is no need to worry about the resin peeling off from each other, and cracking at the adhesive fixing portion 20 and / or the adhesive fixing portion 21 can be prevented. By setting the resin hardness to 60 or less, the hollow fiber membrane 2 can move flexibly near the interface of the adhesive fixing portion 20 and / or the adhesive fixing portion 21, and the breakage of the hollow fiber membrane 2 can be suppressed. Here, "the interface of the adhesive fixing portion" refers to the surface located on the opposite side of the end face of the first adhesive fixing portion 20 and the second adhesive fixing portion 21, and specifically refers to the surface facing the central side of the housing 5, and the same applies below.

[0091] Furthermore, the D hardness of the resin material is more preferably 58 or less, and even more preferably 56 or less. This further suppresses breakage of the hollow fiber membrane 2 near the interface between the adhesive fixing portion 20 and / or the adhesive fixing portion 21. From the viewpoint of obtaining good fixing strength, the D hardness of the resin material is preferably 45 or more, or 50 or more. Additionally, the hardness value of the resin material constituting the end face of the adhesive fixing portion 20 and / or the adhesive fixing portion 21 can be obtained, for example, by measuring the portion of the end face composed only of resin material.

[0092] The aforementioned single thermosetting resin is preferably a two-component curing thermosetting resin. The two-component curing thermosetting resin is preferably, when measured using a type B viscometer, having a viscosity of 1 Pa·s or more and 10 Pa·s or less 10 minutes after the start of mixing the two components, and a viscosity exceeding 100 Pa·s 30 minutes later.

[0093] By ensuring that the viscosity of the thermosetting resin is 1 Pa·s or higher 10 minutes after the start of mixing the two components, unnecessary impregnation of the thermosetting resin into the hollow fiber membrane 2 can be suppressed. On the other hand, if the viscosity is 10 Pa·s or lower 10 minutes after the start of mixing the two components, the injection state of the thermosetting resin is more easily made more uniform. Furthermore, by ensuring that the viscosity exceeds 100 Pa·s after 30 minutes, the leakage of the thermosetting resin into the hollow portion of the hollow fiber membrane 2 can be suppressed. The viscosity 10 minutes after the start of mixing the two components is more preferably 1.5 Pa·s or higher; and more preferably 8 Pa·s or lower or 5 Pa·s or lower. The viscosity 30 minutes after the start of mixing the two components is more preferably 150 Pa·s or higher.

[0094] Prominent Part 50

[0095] Figure 5 This is a schematic diagram showing the potting material P and the hollow fiber membrane 2 constituting the second adhesive fixing part 21. Figure 5As shown, in each hollow fiber membrane 2 near the interface S of the potting material P, there exists a portion where the potting material P is cured while impregnating the hollow fiber membrane 2. This portion is called the protrusion 50.

[0096] The protrusion 50 is formed during the manufacturing process of the hollow fiber membrane assembly 1 when the first bonding and fixing portion 20 and the second bonding and fixing portion 21 are cured. When forming the bonding and fixing portions 20 and 21 using a centrifugal bonding method, the housing 5 is placed horizontally along its length, the potting material P is injected into both ends, and the housing 5 is rotated horizontally with its center as the center. As a result, the potting material P gathers towards both sides of the housing 5 under centrifugal force, thereby forming the first bonding and fixing portion 20 and the second bonding and fixing portion 21. At this time, a portion of the potting material P impregnates towards the central portion of each hollow fiber membrane 2 due to capillary action, and cures in this state to form the protrusion 50.

[0097] The minimum length of the protrusion 50 from the interface S of the potting material P is preferably 3 mm or more and 20 mm or less. Here, the interface S of the potting material P is the surface of the potting material P excluding the protrusion 50 formed in the hollow fiber membrane 2. In addition, the aforementioned minimum length refers to the length of the shortest protrusion 50 among the plurality of protrusions 50 formed in each hollow fiber membrane 2.

[0098] The length of the protrusion 50 is obtained by disassembling the hollow fiber membrane assembly 1, cutting out each hollow fiber membrane 2 from the interface S of the potting material P, and measuring the height from the interface S to the portion of the hollow fiber membrane 2 impregnated by the potting material P.

[0099] In this invention, the inventors discovered that when the minimum length of the protrusion 50 is short, the hollow fiber membrane 2 cannot be flexibly bent near the interface S of the potting material P, and therefore the hollow fiber membrane 2 is more prone to breakage due to oscillation. Furthermore, the inventors discovered that when the filling density of the hollow fiber membrane 2 is high, the length of the protrusion 50 becomes shorter.

[0100] The following explains why the length of the protrusion 50 becomes shorter when the density of the hollow fiber membrane 2 is high. During the formation processes of the first adhesive fixing part 20 and the second adhesive fixing part 21, when the filling density of the hollow fiber membrane 2 is high, the distance between adjacent hollow fiber membranes 2 is short and close, making it difficult for the potting material P to be injected along the length of the shell 5. As a result, since the interface S is formed at a high viscosity without capillary action, the protrusion 50 is not formed, or its length becomes shorter. Furthermore, when the filling density of the hollow fiber membrane 2 is high, the potting material P cannot uniformly fill the end of the shell 5, making poor potting more likely.

[0101] Density Distribution of Hollow Fiber Membrane 2

[0102] Figure 6 Viewed from the direction of arrow A Figure 1 and Figure 2 This is a schematic diagram of the end face 21a of the second adhesive fixing part 21 of the hollow fiber membrane assembly 1. Figure 7 This is a schematic diagram showing a cross-section of a portion of the interior of housing 5. The following will use... Figure 6 and Figure 7 The density distribution of the hollow fiber membrane 2 in the hollow fiber membrane module 1 of this embodiment is described.

[0103] <Macroscopic density distribution on the open end face of hollow fiber membrane 2>

[0104] The hollow fiber membrane assembly 1 of this embodiment is characterized in that, at the end face of the hollow portion opening of the hollow fiber membrane 2 in the first bonding and fixing portion 20 and / or the second bonding and fixing portion 21 (on... Figure 6 In the illustrated embodiment, on the end face 21a) of the second adhesive fixing part 21, the point corresponding to the portion with the smallest thickness in the length direction on the outer peripheral surface of the first adhesive fixing part 20 and / or the second adhesive fixing part 21 having the end face is taken as the upper vertex R. When drawing a horizontal line that is orthogonal to the perpendicular line from the upper vertex R toward the center of the end face and passes through the center, the ratio of the number of hollow fiber membranes 2 above the horizontal line to the number of hollow fiber membranes 2 below the horizontal line (number of hollow fiber membranes 2 above the horizontal line) / (number of hollow fiber membranes 2 below the horizontal line) is 0.9 or more and 1.1 or less. The above ratio is preferably 0.92 or more or 0.95 or more; and preferably 1.08 or less or 1.05 or less.

[0105] The above content will be explained in detail. Figure 7 The thickness of the second adhesive fixing part 21 shown is uneven, with some parts being thicker and others thinner in both the first adhesive fixing part 20 and the second adhesive fixing part 21. Figure 7 In the second adhesive fixing part 21 shown, the distance between points RR′ is the minimum thickness on the outer peripheral surface of the second adhesive fixing part 21. Figure 7 When the end face 21a of the second adhesive fixing part 21 is viewed from above, the part with the smallest thickness on the outer peripheral surface of the second adhesive fixing part 21 corresponds to point R.

[0106] Figure 6The horizontal line EF is a horizontal line that is orthogonal to the perpendicular line from the aforementioned upper vertex R toward the center of the end face 21a and passes through the center. In this embodiment, the hollow fiber membrane assembly 1 is characterized in that the end face 21a is divided into an upper region and a lower region by the horizontal line EF, and the ratio of the number of hollow fiber membranes 2 located on the upper side of the horizontal line EF to the number of hollow fiber membranes 2 located on the lower side (number of hollow fiber membranes 2 on the upper side) / (number of hollow fiber membranes 2 on the lower side) is 0.9 or more and 1.1 or less. Furthermore, when hollow fiber membranes 2 are present on the horizontal line EF, the number of membranes is counted in the region where the cross-sectional area of ​​the hollow fiber membrane 2 occupies a larger proportion.

[0107] Therefore, on the end face 21a of the second bonding and fixing portion 21, which serves as one end of the hollow fiber membrane bundle 3, the density distribution of the hollow fiber membrane 2 can be made uniform overall, thus suppressing the breakage of the hollow fiber membrane 2 due to oscillation. Furthermore, as a result of making the density distribution of the hollow fiber membrane 2 uniform overall on the end face 21a, compared to the case where there are locally higher densities in the hollow fiber membrane 2, the minimum length of the protrusion 50 near the second bonding and fixing portion 21 can be increased. By increasing the minimum length of the protrusion 50, the hollow fiber membrane 2 can be flexibly bent near the second bonding and fixing portion 21, preventing the hollow fiber membrane 2 from breaking due to oscillation.

[0108] exist Figure 6 and Figure 7 In this paper, the end face of the opening of the hollow fiber membrane 2 is described as the second bonding and fixing part 21, but the same applies when the end face of the opening of the hollow fiber membrane 2 is the first bonding and fixing part 20.

[0109] <Density distribution on virtual bonding interface S′>

[0110] In one implementation scheme, when making Figure 7 On the virtual bonding interface S', the end face 21a of the hollow opening of the hollow fiber membrane 2 of the second bonding fixing part 21 is virtually parallel to the center of the length direction and moves towards the virtual bonding interface S', which is the amount of the thickness RR′ of the thinnest part in the length direction on the outer peripheral surface of the second bonding fixing part 21. The total cross-sectional area of ​​all hollow fiber membranes 2 / the internal cross-sectional area of ​​the shell 5 is preferably 20% or more, or 22% or more, or 25% or more; and preferably 50% or less, or 48% or less, or 45% or less.

[0111] By setting the fill rate (i.e., the total cross-sectional area of ​​all hollow fiber membranes 2 / the internal cross-sectional area of ​​the shell 5) on the virtual bonding interface S' to 50% or less, the gap between the hollow fiber membranes 2 can be sufficiently ensured, and the potting material can be easily and uniformly injected between the hollow fiber membranes 2. On the other hand, by setting the fill rate to 20% or more, the proportion of potting material in the first bonding fixing part 20 and / or the second bonding fixing part 21 can be kept small, thereby suppressing cracking or peeling at the first bonding fixing part 20 and / or the second bonding fixing part 21 due to curing shrinkage.

[0112] In one embodiment, on the virtual bonding interface S', the point corresponding to the portion with the smallest thickness in the length direction on the outer peripheral surface is designated as the upper vertex R'. When drawing a horizontal line that is orthogonal to the perpendicular line from the upper vertex R' toward the center of the virtual bonding interface S' and passes through the center, the ratio of the number of hollow fiber membranes 2 located above the horizontal line to the number of hollow fiber membranes 2 located below (number of hollow fiber membranes 2 on the upper side) / (number of hollow fiber membranes 2 on the lower side) is preferably 0.85 or more, or 0.88 or more, or 0.90 or more; and preferably 1.15 or less, or 1.12 or less, or 1.10 or less. Furthermore, when hollow fiber membranes 2 are present on the horizontal line, the number of membranes is included in the area where the cross-sectional area of ​​the hollow fiber membrane 2 occupies a larger proportion. The same applies when the end face of the opening of the hollow fiber membrane 2 is the first bonding fixing part 20.

[0113] Therefore, the density distribution of the hollow fiber membrane 2 can be made uniform overall at the virtual bonding interface S' of the first bonding and fixing part 20 and / or the second bonding and fixing part 21. Compared with the end face of the first bonding and fixing part 20 and / or the second bonding and fixing part 21, the density distribution of the hollow fiber membrane 2 can be made uniform overall at the virtual bonding interface S' which is closer to the center of the hollow fiber membrane bundle 3, thereby further suppressing the breakage of the hollow fiber membrane 2 due to oscillation.

[0114] Furthermore, as a result of achieving an overall uniform density distribution of the hollow fiber membrane 2 at the virtual bonding interface S' of the first bonding fixing portion 20 and / or the second bonding fixing portion 21, the minimum length of the protrusion 50 in the hollow fiber membrane bundle 3 can be increased compared to the case where there are locally higher densities of the hollow fiber membrane 2. By increasing the minimum length of the protrusion 50, the hollow fiber membrane 2 can be flexibly bent near the interface of the first bonding fixing portion 20 and / or the second bonding fixing portion 21, preventing the hollow fiber membrane 2 from breaking due to oscillation.

[0115] <Micro density distribution on the open end face of hollow fiber membrane 2>

[0116] Figure 8 Viewed from the direction of arrow A Figure 1 and Figure 2 This is a schematic diagram of the end face 21a of the second adhesive fixing portion 21 of the hollow fiber membrane assembly 1. In one embodiment of the hollow fiber membrane assembly 1, the end face of the hollow portion opening of the hollow fiber membrane 2 in the first adhesive fixing portion 20 and / or the second adhesive fixing portion 21 (at...) Figure 8 In the illustrated embodiment, on the end face 21a) of the second adhesive fixing part 21, there are defined a first circle F1, which is a circle with the smallest diameter including all the hollow fiber membranes present on the end face; a second circle F2, which is concentric with the first circle F1 and has a diameter 2 cm smaller than the first circle F1; a first square F3, which is the largest of the squares located in the center of the second circle F2 (i.e., concentric with the circle F2) with a side length of N cm (where N is a natural number); and N squares formed by dividing the first square F3 into 1 cm squares. 2 When there are two second squares F4, the ratio of the minimum to the maximum number of hollow fiber membranes 2 contained in each second square F4 is preferably 0.4 or higher, or 0.42 or higher, or 0.45 or higher. When hollow fiber membranes 2 are present on the sides of a second square F4, the number of membranes is counted in the second square that contains the largest proportion of the cross-sectional area of ​​the hollow fiber membrane 2. Furthermore, in... Figure 8 In this paper, the end face of the opening of the hollow fiber membrane 2 is described as the second bonding and fixing part 21, but the same applies when the end face of the opening of the hollow fiber membrane 2 is the first bonding and fixing part 20.

[0117] In the assembly, if there are areas where the hollow fiber membrane is too densely packed, the adhesive will have difficulty penetrating between the hollow fiber membranes in these areas, and the thickness of the bonded fixing portion will tend to be smaller. On the other hand, if there are areas where the hollow fiber membrane is too sparsely packed, the hollow fiber membrane will tend to wobble and break easily in these areas. The aforementioned (minimum) / (maximum) ratio within the above range means that the degree of local over-dense or under-dense packing of the hollow fiber membrane is small, and the above problems can be well avoided. The (minimum) / (maximum) ratio is preferably 1.

[0118] <Shapes of the first adhesive fixing part 20 and the second adhesive fixing part 21>

[0119] Figure 9 This is a schematic diagram showing a cross-section of a portion inside the housing 5 to illustrate the shape of the interface of the second adhesive fixing part 21. Figure 9 A is based on Figure 6 A cross-sectional view of shell 5 along the horizontal line EF. Figure 9 In the cross-section shown in (A), the interface of the second adhesive fixing part 21 is an arc shape with high ends and low center. This is due to the centrifugal force exerted on the potting material during the centrifugal bonding process. Figure 9The influence of arrow G in (A) and the shape of the arc depends on the radius of rotation in the centrifugal bonding process and the inner diameter of the housing 5.

[0120] In this embodiment, (the average of the thickness L1 of the second adhesive fixing part 21 at one intersection of the outer peripheral surface of the second adhesive fixing part 21 and the thickness L2 of the second adhesive fixing part 21 at the other intersection of the outer peripheral surface of the second adhesive fixing part 21 and the horizontal line EF) - (the average of the thickness L1 of the second adhesive fixing part 21 at the center of the end face 21a of the second adhesive fixing part 21) О The difference between the two parts is preferably 1 mm or more, or 1.5 mm or more, or 2 mm or more; and preferably 12 mm or less, or 10 mm or less, or 8 mm or less. The same applies to the first adhesive fixing part 20.

[0121] Figure 9 (B) indicates that it is based on... Figure 6 A schematic diagram of a cross-section of a portion of the interior of the housing 5, perpendicular to the vertical line from the upper vertex R of the housing 5 to the center of the end face 21a of the second adhesive fixing part 21. The vertical direction of the housing 5 during the centrifugal bonding process is... Figure 9 (B) has the same vertical direction. Figure 9 In the cross-section shown in (B), the interface of the second adhesive fixing part 21 is inclined, with the upper side lower and the lower side higher. During the centrifugal bonding process, the potting material is subjected to gravity in the lower direction and centrifugal force from the center of rotation outwards. Figure 9 (B) arrow G), therefore the degree of tilt of the interface depends on the magnitude of the centrifugal force.

[0122] In this embodiment, the thickness L4 of the second adhesive fixing part 21 at the intersection of the perpendicular line from the upper vertex R towards the center of the end face 21a of the second adhesive fixing part 21 and another point on the outer peripheral surface of the second adhesive fixing part 21, and the thickness L3 of the second adhesive fixing part 21 at the upper vertex R, is preferably 3 mm or more, or 3.5 mm or more, or 4 mm or more; and preferably 12 mm or less, or 11 mm or less, or 10 mm or less. The same applies to the first adhesive fixing part 20.

[0123] <Thickness of the first adhesive fixing part 20 and the second adhesive fixing part 21>

[0124] The thickness of the first adhesive fixing portion 20 and / or the second adhesive fixing portion 21 at the end face of the hollow portion opening of the hollow fiber membrane 2 preferably has a small local deviation. Figure 10 This is a diagram showing the end face of the hollow section opening of the hollow fiber membrane in the conventional hollow fiber membrane module shown in Comparative Example 1, which will be described later. In conventional hollow fiber membrane modules, such as Figure 10As shown, due to the formation of the membrane bundle by the limiting member 41, there are variations in the density of the hollow fiber membrane within the hollow fiber membrane bundle. When injecting the potting material, the amount of potting material injected depends on the density of the hollow fiber membrane, resulting in a large deviation in the thickness of the bonding and fixing portion. Thus, when the thickness deviation of the first bonding and fixing portion 20 and / or the second bonding and fixing portion 21 is large, there are problems such as weak pressure resistance. However, as described above, this problem can be solved by reducing the thickness deviation of the first bonding and fixing portion 20 and / or the second bonding and fixing portion 21.

[0125] Example

[0126] Next, embodiments and comparative examples of the hollow fiber membrane module of the present invention will be described, but the present invention is not limited to these embodiments.

[0127] (Example 1)

[0128] 16,500 PVDF (polyvinylidene fluoride) hollow fiber membranes (manufactured by Asahi Kasei) were bundled together at a length of 2.3 m, suspended vertically, and the lower end faces were cut to align them. Next, repair tape was applied around the entire circumference of the membrane bundle to achieve a circumference of 170 mm. Further, 300 g of polyurethane resin SA-8100A / SA-8100B (manufactured by SANYU REC) was measured using a mixing sprayer and impregnated on the lower surface of the membrane bundle for 30 seconds, then immediately separated. Afterward, the bundle was left at room temperature for 4 hours to allow the polyurethane resin impregnated on the lower surface of the membrane bundle to cure, sealing the hollow portion while maintaining the specified membrane bundle diameter. The membrane bundle thus prepared was inserted into a housing having a second cylindrical member (end face diameter 218 mm) with a rectifier tube mounted on its inner side with an inner diameter of 216 mm. The hollow fiber membranes used had an average pore size of 0.1 μm, an inner diameter of 0.6 mm, and an outer diameter of 1.0 mm.

[0129] Next, at the end of the hollow fiber membrane bundle on the first cylindrical member side, a columnar member is inserted at the position where a through hole is to be formed.

[0130] Next, the adhesive fixing part of the container, which houses the potting material inlet tube, is fixed to both ends of the shell. While rotating it horizontally, the potting material is injected into the first and second cylindrical components of the shell. As the potting material, a two-component thermosetting polyurethane resin (SANYU REC: SA-6330A2 / SA-6330B5 (trade name), viscosity after 10 minutes of mixing measured at 25°C: 3.5 Pa·s, viscosity after 30 minutes of mixing measured at 25°C: 210 Pa·s) is used. When the potting material stops flowing due to the curing reaction, the centrifuge is stopped and the material is removed and heated to 50°C in an oven to cure. Furthermore, the viscosity after 10 minutes and 30 minutes of mixing is measured using a type B viscometer.

[0131] Then, the end of the shell on the second cylindrical member side is cut off, making the total length of the shell 2.1m, thereby sealing the hollow opening on one side of the hollow portion before bonding. On the other hand, the columnar member is removed from the first bonding fixing part on the first cylindrical member side, thereby forming multiple through holes. Furthermore, the effective membrane length of this hollow fiber membrane assembly is 2m.

[0132] At this point, on the end face of the hollow fiber membrane opening of the second bonding and fixing part, the point corresponding to the thinnest part on the outer peripheral surface of the second bonding and fixing part is taken as the upper vertex. When drawing a horizontal line that is orthogonal to the perpendicular line from the vertex towards the center of the end face and passes through the center, the number of hollow fiber membranes above the horizontal line is 8099, and the number of hollow fiber membranes below the horizontal line is 8401. That is, the ratio of the number of hollow fiber membranes to the number of hollow fiber membranes located on the lower side (number of hollow fiber membranes on the upper side) / (number of hollow fiber membranes on the lower side) is 0.96. The filling rate of the manufactured hollow fiber membrane assembly is 34.7%.

[0133] On the end face of the hollow fiber membrane opening of the second adhesive fixing part, a first circle is defined as the smallest circle containing all the hollow fiber membranes present on the end face; a second circle is concentric with the first circle and has a diameter 2 cm smaller; a first square of 10 cm square, which is the largest among the squares located in the center of the second circle and with a side length of N cm (where N is a natural number); and 100 (=10×10) second squares are formed by dividing the first square into 1 cm squares. Regarding the number of hollow fiber membranes contained in each second square, the minimum value among the 100 is 50, and the maximum value is 91, therefore (minimum value) / (maximum value) = 0.55. Furthermore, when hollow fiber membranes are present on the sides of the second square, the number of membranes is counted in the second square that contains the largest proportion of the cross-sectional area of ​​the hollow fiber membrane.

[0134] Additionally, in the second adhesive fixing part, (the average value of L1 and L2) - L o =6mm, L4-L3 =9mm.

[0135] The resin fixing part on the end face of the manufactured hollow fiber membrane module has a (JIS K7215) D hardness of 55D. In the hardness measurement of the resin fixing part, the load holding time was set to 10 seconds, and the hardness value was the average of 5 points randomly selected on the end face of the adhesive fixing part.

[0136] The filling rate of the hollow fiber membrane at the virtual bonding interface S' of the second bonding and fixing part of the manufactured hollow fiber membrane module is 32.6%. Furthermore, in the virtual bonding interface S', taking the point corresponding to the part with the smallest thickness on the outer peripheral surface as the upper vertex, when drawing a horizontal line that is orthogonal to the perpendicular line from the upper vertex towards the center of the virtual bonding interface S' and passes through the center, the ratio of the number of hollow fiber membranes above the horizontal line to the number of hollow fiber membranes below the horizontal line (number of hollow fiber membranes above) / (number of hollow fiber membranes below) is 0.92.

[0137] Next, with the side of the hollow opening facing upwards, the hollow fiber membrane module is installed on the filter device, and the following physical cleaning durability test is conducted.

[0138] From the second adhesive fixing part on the upper side, 7m 3 The washing water is supplied at a flow rate of / hr, while maintaining a flow rate of 8.5Nm. 3 Air is supplied at a flow rate of / hr through the first adhesive fixing part on the lower side. The two supplied fluids are discharged from the nozzle of the second cylindrical member on the upper side. The above operation was carried out continuously except for monthly leak tests. In addition, the water temperature was maintained at 10°C during operation.

[0139] After six months of operation, five leaks occurred due to hollow fiber membrane rupture. Following the test, the membrane module was disassembled to confirm the condition of the second bonding and fixing section. The thickest part of the second bonding and fixing section was 70 mm, and the thinnest part was 66 mm, with a maximum thickness minus a minimum thickness of 4 mm. Additionally, the minimum length of the hollow fiber membrane protrusion in the longitudinal direction was 5 mm.

[0140] (Example 2)

[0141] Except for the use of 11,000 PVDF (polyvinylidene fluoride) hollow fiber membranes (manufactured by Asahi Kasei), the application of repair tape around the circumference of the membrane bundle to achieve a circumference of 135 mm, the end face diameter of the second cylindrical member being 168 mm, and the inner diameter of the rectifier being 165 mm, the hollow fiber membrane module was manufactured and evaluated in the same manner as in Example 1.

[0142] At this point, on the end face of the hollow fiber membrane opening of the second bonding and fixing part, the point corresponding to the thinnest part on the outer peripheral surface of the second bonding and fixing part is taken as the upper vertex. When drawing a horizontal line that is orthogonal to the perpendicular line from the vertex towards the center of the end face and passes through the center, the number of hollow fiber membranes above the horizontal line is 5365, and the number of hollow fiber membranes below the horizontal line is 5635. That is, (number of hollow fiber membranes on the upper side) / (number of hollow fiber membranes on the lower side) is 0.95. The filling rate of the manufactured hollow fiber membrane assembly is 39%. Other measurement results are shown in Table 1.

[0143] (Example 3)

[0144] Except that 11,500 PVDF (polyvinylidene fluoride) hollow fiber membranes (manufactured by Asahi Kasei) were used, and the average pore size of the hollow fiber membranes used was 0.1 μm, the inner diameter was 0.7 mm, and the outer diameter was 1.22 mm, the hollow fiber membrane module was manufactured in the same manner as in Example 1, and its evaluation was carried out.

[0145] At this point, on the end face of the hollow fiber membrane opening of the second bonding and fixing part, the point corresponding to the thinnest part on the outer peripheral surface of the second bonding and fixing part is taken as the upper vertex. When drawing a horizontal line that is orthogonal to the perpendicular line from the vertex towards the center of the end face and passes through the center, the number of hollow fiber membranes above the horizontal line is 5703, and the number of hollow fiber membranes below the horizontal line is 5797. That is, (number of hollow fiber membranes on the upper side) / (number of hollow fiber membranes on the lower side) is 0.98. The filling rate of the manufactured hollow fiber membrane module is 36%. Other measurement results are shown in Table 1.

[0146] (Example 4)

[0147] Except that a hollow fiber membrane module was manufactured in the same manner as in Example 2, using 6600 PVDF (polyvinylidene fluoride) hollow fiber membranes (manufactured by Asahi Kasei) and the hollow fiber membranes used had an average pore size of 0.1 μm, an inner diameter of 0.7 mm, and an outer diameter of 1.22 mm, the module was evaluated.

[0148] At this point, on the end face of the hollow fiber membrane opening of the second bonding and fixing part, the point corresponding to the thinnest part on the outer peripheral surface of the second bonding and fixing part is taken as the upper vertex. When drawing a horizontal line that is orthogonal to the perpendicular line from the vertex towards the center of the end face and passes through the center, the number of hollow fiber membranes on the upper side of this horizontal line is 3215, and the number of hollow fiber membranes on the lower side is 3385. That is, (number of hollow fiber membranes on the upper side) / (number of hollow fiber membranes on the lower side) is 0.95. The filling rate of the manufactured hollow fiber membrane assembly is 34.8%. Other measurement results are shown in Table 1.

[0149] (Example 5)

[0150] Except that 6,000 PVDF (polyvinylidene fluoride) hollow fiber membranes (manufactured by Asahi Kasei) were used, and the average pore size of the hollow fiber membranes used was 0.02 μm, the inner diameter was 0.7 mm, and the outer diameter was 1.3 mm, the hollow fiber membrane module was manufactured in the same manner as in Example 2, and its evaluation was carried out.

[0151] At this point, on the end face of the hollow fiber membrane opening of the second bonding and fixing part, the point corresponding to the thinnest part on the outer peripheral surface of the second bonding and fixing part is taken as the upper vertex. When drawing a horizontal line that is orthogonal to the perpendicular line from the vertex towards the center of the end face and passes through the center, the number of hollow fiber membranes above the horizontal line is 2970, and the number of hollow fiber membranes below the horizontal line is 3030. That is, (number of hollow fiber membranes on the upper side) / (number of hollow fiber membranes on the lower side) is 0.98. The filling rate of the manufactured hollow fiber membrane module is 35.9%. Other measurement results are shown in Table 1.

[0152] (Example 6)

[0153] Except for the use of 8300 PVDF (polyvinylidene fluoride) hollow fiber membranes (manufactured by Asahi Kasei) as potting material, and the use of a two-component thermosetting polyurethane resin (manufactured by Sanyo Kasei Corporation: JA-553 / JB-553 (trade name), viscosity after 10 minutes of mixing at 25°C: 2.5 Pa·s, viscosity after 30 minutes of mixing at 25°C: 170 Pa·s), the hollow fiber membrane module was manufactured and evaluated in the same manner as in Example 3.

[0154] At this point, on the end face of the hollow fiber membrane opening of the second bonding and fixing part, the point corresponding to the smallest thickness on the outer peripheral surface of the second bonding and fixing part is taken as the upper vertex. When drawing a horizontal line that is orthogonal to the perpendicular line from the vertex toward the center of the end face and passes through the center, the number of hollow fiber membranes above the horizontal line is 4071, and the number of hollow fiber membranes below the horizontal line is 4229. That is, (number of hollow fiber membranes on the upper side) / (number of hollow fiber membranes on the lower side) is 0.96. The filling rate of the manufactured hollow fiber membrane assembly is 26.0%. Furthermore, in this hollow fiber membrane assembly, a gap can be seen in the length direction in a portion of the circumferential direction of the surface where the bonding and fixing part is bonded to the shell. Other measurement results are shown in Table 1.

[0155] (Example 7)

[0156] Except for using 8800 PVDF (polyvinylidene fluoride) hollow fiber membranes (manufactured by Asahi Kasei), setting the total length of the bundled membrane to 1.6m, attaching repair tape around the circumference of the membrane bundle to achieve a circumference of 110mm, using a second cylindrical member with an end face diameter of 140mm, a rectifier inner diameter of 135mm, and setting the total length of the shell after cutting off the ends of the hollow fiber membrane bundle to 1.4m, the hollow fiber membrane module was manufactured and evaluated in the same manner as in Example 1.

[0157] At this point, on the end face of the hollow fiber membrane opening of the second bonding and fixing part, the point corresponding to the smallest thickness on the outer peripheral surface of the second bonding and fixing part is taken as the upper vertex. When drawing a horizontal line that is orthogonal to the perpendicular line from the vertex towards the center of the end face and passes through the center, the number of hollow fiber membranes above the horizontal line is 4316, and the number of hollow fiber membranes below the horizontal line is 4484. That is, (number of hollow fiber membranes on the upper side) / (number of hollow fiber membranes on the lower side) is 0.96. The filling rate of the manufactured hollow fiber membrane assembly is 44.9%. Other measurement results are shown in Table 1.

[0158] (Example 8)

[0159] Except for the use of 3100 PVDF (polyvinylidene fluoride) hollow fiber membranes (manufactured by Asahi Kasei), the application of repair tape around the circumference of the membrane bundle to achieve a circumference of 75 mm, the end face diameter of the second cylindrical member being 84 mm, and the inner diameter of the rectifier being 79 mm, the hollow fiber membrane module was manufactured and evaluated in the same manner as in Example 1.

[0160] At this point, on the end face of the hollow fiber membrane opening of the second bonding and fixing part, the point corresponding to the thinnest part on the outer peripheral surface of the second bonding and fixing part is taken as the upper vertex. When drawing a horizontal line that is orthogonal to the perpendicular line from the vertex towards the center of the end face and passes through the center, the number of hollow fiber membranes above the horizontal line is 1485, and the number of hollow fiber membranes below the horizontal line is 1615. That is, (number of hollow fiber membranes on the upper side) / (number of hollow fiber membranes on the lower side) is 0.92. The filling rate of the manufactured hollow fiber membrane module is 43.9%. Other measurement results are shown in Table 1.

[0161] (Example 9)

[0162] Except that the total length of the hollow fiber membrane (manufactured by Asahi Kasei) made of PVDF (polyvinylidene fluoride) was set to 1.2m and the total length of the shell after the ends of the hollow fiber membrane bundle were cut off was set to 1.0m, the hollow fiber membrane module was manufactured in the same manner as in Example 4 and evaluated.

[0163] At this point, on the end face of the hollow fiber membrane opening of the second bonding and fixing part, the point corresponding to the smallest thickness on the outer peripheral surface of the second bonding and fixing part is taken as the upper vertex. When drawing a horizontal line that is orthogonal to the perpendicular line from the vertex towards the center of the end face and passes through the center, the number of hollow fiber membranes above the horizontal line is 3294, and the number of hollow fiber membranes below the horizontal line is 3306. That is, (number of hollow fiber membranes on the upper side) / (number of hollow fiber membranes on the lower side) is 1.00. The filling rate of the manufactured hollow fiber membrane module is 34.8%. Other measurement results are shown in Table 1.

[0164] (Example 10)

[0165] Except for the use of 11,000 PVDF (polyvinylidene fluoride) hollow fiber membranes (manufactured by Asahi Kasei), hollow fiber membrane modules were manufactured and evaluated in the same manner as in Example 4.

[0166] At this point, on the end face of the hollow fiber membrane opening of the second bonding and fixing part, the point corresponding to the thinnest part on the outer peripheral surface of the second bonding and fixing part is taken as the upper vertex. When drawing a horizontal line that is orthogonal to the perpendicular line from the vertex towards the center of the end face and passes through the center, the number of hollow fiber membranes above the horizontal line is 5527, and the number of hollow fiber membranes below the horizontal line is 5473. That is, (number of hollow fiber membranes on the upper side) / (number of hollow fiber membranes on the lower side) is 1.01. The filling rate of the manufactured hollow fiber membrane assembly is 58.0%. Other measurement results are shown in Table 1.

[0167] (Example 11)

[0168] Except for the use of 21,000 PVDF (polyvinylidene fluoride) hollow fiber membranes (manufactured by Asahi Kasei), hollow fiber membrane modules were manufactured in the same manner as in Example 1, and their evaluation was conducted.

[0169] At this point, on the end face of the hollow fiber membrane opening of the second bonding and fixing part, the point corresponding to the thinnest part on the outer peripheral surface of the second bonding and fixing part is taken as the upper vertex. When drawing a horizontal line that is orthogonal to the perpendicular line from the vertex towards the center of the end face and passes through the center, the number of hollow fiber membranes on the upper side of this horizontal line is 10286, and the number of hollow fiber membranes on the lower side is 10714. That is, (number of hollow fiber membranes on the upper side) / (number of hollow fiber membranes on the lower side) is 0.96. The filling rate of the manufactured hollow fiber membrane module is 44.2%. Other measurement results are shown in Table 1.

[0170] (Example 12)

[0171] Except for the use of 6,000 PVDF (polyvinylidene fluoride) hollow fiber membranes (manufactured by Asahi Kasei), hollow fiber membrane modules were manufactured in the same manner as in Example 2, and their evaluation was conducted.

[0172] At this point, on the end face of the hollow fiber membrane opening of the second bonding and fixing part, the point corresponding to the smallest thickness on the outer peripheral surface of the second bonding and fixing part is taken as the upper vertex. When drawing a horizontal line that is orthogonal to the perpendicular line from the vertex toward the center of the end face and passes through the center, the number of hollow fiber membranes above the horizontal line is 2846, and the number of hollow fiber membranes below the horizontal line is 3154. That is, (number of hollow fiber membranes on the upper side) / (number of hollow fiber membranes on the lower side) is 0.90. The filling rate of the manufactured hollow fiber membrane assembly is 21.3%. Furthermore, in this hollow fiber membrane assembly, a gap can be seen in the length direction in a portion of the circumferential direction of the surface where the bonding and fixing part is bonded to the shell. Other measurement results are shown in Table 1.

[0173] (Comparative Example 1)

[0174] 16,500 PVDF (polyvinylidene fluoride) hollow fiber membranes (manufactured by Asahi Kasei) were bundled together and inserted into a shell containing a second cylindrical component (end face diameter 218 mm) with an inner diameter rectifier cylinder mounted on its inner side. The hollow fiber membranes used had an average pore size of 0.1 μm, an inner diameter of 0.6 mm, and an outer diameter of 1.0 mm.

[0175] Next, at the end of the hollow fiber membrane bundle on one side of the hollow section sealed with plaster, such as Figure 10 The diagram shows the insertion configuration of 12 cylindrical constraint members with an outer diameter of 11 mm (these members are formed by pre-casting an adhesive, the same as the potting material described below, into a mold and allowing it to cure). On the other hand, columnar members are inserted at the ends of the hollow fiber membrane bundle on the first cylindrical member side, at positions where through holes are predetermined. Subsequently, the hollow fiber membrane assembly is manufactured in the same manner as in Example 1, and its evaluation is performed.

[0176] like Figure 10 As shown, on the end face of the hollow opening of the hollow fiber membrane, the point R corresponding to the thinnest part on the outer peripheral surface of the second adhesive fixing part of the end face of the hollow opening of the hollow fiber membrane is taken as the upper vertex. When drawing a horizontal line that is orthogonal to the perpendicular line from point R toward the center of the end face and passes through the center, the number of hollow fiber membranes above the horizontal line is 7641 and the number of hollow fiber membranes below the horizontal line is 8859. That is, (number of hollow fiber membranes on the upper side) / (number of hollow fiber membranes on the lower side) is 0.86.

[0177] Next, with the side of the hollow opening facing upwards, the hollow fiber membrane module is installed on the filter device, and the following physical cleaning durability test is conducted.

[0178] From the second adhesive fixing part side above, 7m 3 The washing water is supplied at a flow rate of / hr, while maintaining a flow rate of 8.5Nm. 3 Air is supplied at a flow rate of / hr through the first adhesive fixing part on the lower side. The two supplied fluids are discharged from the nozzle of the second cylindrical member on the upper side. The above operation was carried out continuously except for monthly leak tests. In addition, the water temperature was maintained at 10°C during operation.

[0179] After 6 months of operation, 105 leaks occurred due to membrane rupture. Following the test, the membrane module was disassembled to confirm the condition of the second adhesive fixing part. The thickness of the second adhesive fixing part ranged from 54 mm to 69 mm, and the minimum and maximum length of the protrusion was 2 mm. Other measurement results are shown in Table 2.

[0180] (Comparative Example 2)

[0181] Except for not using a restricting member at the end of the hollow fiber membrane bundle on the side where the hollow portion is sealed with plaster, the hollow fiber membrane assembly was manufactured in the same manner as in Comparative Example 1, and its evaluation was carried out.

[0182] At this point, on the end face of the hollow opening of the hollow fiber membrane, the point corresponding to the thinnest part on the outer peripheral surface of the adhesive fixing part of the end face with the hollow opening of the hollow fiber membrane is taken as the upper vertex. When drawing a horizontal line that is orthogonal to the perpendicular line from the vertex toward the center of the end face and passes through the center, the number of hollow fiber membranes above the horizontal line is 6513 and the number of hollow fiber membranes below the horizontal line is 9987. That is, (number of hollow fiber membranes on the upper side) / (number of hollow fiber membranes on the lower side) is 0.65. Other measurement results are shown in Table 2.

[0183] (Comparative Example 3)

[0184] Except for the fact that a plate-shaped limiting member with a thickness of 3 mm, a width of 210 mm, and a length of 50 mm is provided at the end of the hollow fiber membrane bundle on the side where the hollow part is sealed with gypsum (the member is formed by casting the same adhesive as the potting material described below into the mold and then curing it), 11,500 PVDF (polyvinylidene fluoride) hollow fiber membranes (manufactured by Asahi Kasei) are used, and the hollow fiber membranes used have an average pore size of 0.1 μm, an inner diameter of 0.7 mm, and an outer diameter of 1.22 mm, the hollow fiber membrane assembly was manufactured in the same manner as Comparative Example 1, and its evaluation was carried out.

[0185] At this point, on the end face of the hollow opening of the hollow fiber membrane, the point corresponding to the thinnest part on the outer peripheral surface of the adhesive fixing part of the end face with the hollow opening of the hollow fiber membrane is taken as the upper vertex. When drawing a horizontal line that is orthogonal to the perpendicular line from the vertex toward the center of the end face and passes through the center, the number of hollow fiber membranes above the horizontal line is 5350 and the number of hollow fiber membranes below the horizontal line is 6150. That is, (number of hollow fiber membranes on the upper side) / (number of hollow fiber membranes on the lower side) is 0.87. Other measurement results are shown in Table 2.

[0186] (Comparative Example 4)

[0187] Except that a limiting member was not used at the end of the hollow fiber membrane bundle on the side where the hollow part was sealed with gypsum, 11,000 PVDF (polyvinylidene fluoride) hollow fiber membranes (manufactured by Asahi Kasei) were used, the end face diameter of the second cylindrical member used was 168 mm, and the inner diameter of the rectifier tube was 165 mm, the hollow fiber membrane assembly was manufactured in the same manner as Comparative Example 1 and its evaluation was carried out.

[0188] At this point, on the end face of the hollow section opening of the hollow fiber membrane, the point corresponding to the thinnest part on the outer peripheral surface of the adhesive fixing part of the end face with the hollow section opening of the hollow fiber membrane is taken as the upper vertex. When drawing a horizontal line that is orthogonal to the perpendicular line from the vertex toward the center of the end face and passes through the center, the number of hollow fiber membranes above the horizontal line is 4453 and the number of hollow fiber membranes below the horizontal line is 6547. That is, (number of hollow fiber membranes on the upper side) / (number of hollow fiber membranes on the lower side) is 0.68. Other measurement results are shown in Table 2.

[0189] (Comparative Example 5)

[0190] 11,000 PVDF (polyvinylidene fluoride) hollow fiber membranes (manufactured by Asahi Kasei) were bundled together and inserted into a shell containing a second cylindrical member (end face diameter 168 mm) with an inner diameter rectifier cylinder mounted on its inner side (165 mm). The hollow fiber membranes used had an average pore size of 0.1 μm, an inner diameter of 0.6 mm, and an outer diameter of 1.0 mm. At the end of the hollow fiber membrane bundle on the side where the hollow portion was sealed with plaster, such as... Figure 10 The diagram shows the insertion configuration of 12 cylindrical constraint members with an outer diameter of 11 mm (these members are formed by pre-casting an adhesive, the same as the potting material described below, into a mold and allowing it to cure). On the other hand, columnar members are inserted at the ends of the hollow fiber membrane bundle on the first cylindrical member side, at positions where through holes are predetermined. Subsequently, the hollow fiber membrane assembly is manufactured in the same manner as in Example 1, and its evaluation is performed.

[0191] At this point, on the end face of the hollow opening of the hollow fiber membrane, the point corresponding to the thinnest part on the outer peripheral surface of the adhesive fixing part of the end face with the hollow opening of the hollow fiber membrane is taken as the upper vertex. When drawing a horizontal line that is orthogonal to the perpendicular line from the vertex toward the center of the end face and passes through the center, the number of hollow fiber membranes above the horizontal line is 5180 and the number of hollow fiber membranes below the horizontal line is 5820. That is, (number of hollow fiber membranes on the upper side) / (number of hollow fiber membranes on the lower side) is 0.89. Other measurement results are shown in Table 2.

[0192] (Comparative Example 6)

[0193] Except that a limiting member was not used at the end of the hollow fiber membrane bundle on the side where the hollow part was sealed with gypsum, 3100 PVDF (polyvinylidene fluoride) hollow fiber membranes (manufactured by Asahi Kasei) were used, the end face diameter of the second cylindrical member used was 84 mm, and the inner diameter of the rectifier tube was 79 mm, the hollow fiber membrane module was manufactured in the same manner as Comparative Example 1, and its evaluation was carried out.

[0194] At this point, on the end face of the hollow opening of the hollow fiber membrane, the point corresponding to the thinnest part on the outer peripheral surface of the adhesive fixing part of the end face with the hollow opening of the hollow fiber membrane is taken as the upper vertex. When drawing a horizontal line that is orthogonal to the perpendicular line from the vertex toward the center of the end face and passes through the center, the number of hollow fiber membranes above the horizontal line is 1329, and the number of hollow fiber membranes below the horizontal line is 1771. That is, (number of hollow fiber membranes on the upper side) / (number of hollow fiber membranes on the lower side) is 0.82. Other measurement results are shown in Table 2.

[0195] (Comparative Example 7)

[0196] Except that the total length of the hollow fiber membrane (manufactured by Asahi Kasei) when bundled with PVDF (polyvinylidene fluoride) was set to 1.2m, and the total length of the shell after the ends of the hollow fiber membrane bundle were cut off was set to 1.0m, the hollow fiber membrane module was manufactured in the same manner as Comparative Example 1, and its evaluation was carried out.

[0197] At this point, on the end face of the hollow opening of the hollow fiber membrane, the point corresponding to the thinnest part on the outer peripheral surface of the adhesive fixing part of the end face with the hollow opening of the hollow fiber membrane is taken as the upper vertex. When drawing a horizontal line that is orthogonal to the perpendicular line from the vertex toward the center of the end face and passes through the center, the number of hollow fiber membranes above the horizontal line is 7384, and the number of hollow fiber membranes below the horizontal line is 9116. That is, (number of hollow fiber membranes on the upper side) / (number of hollow fiber membranes on the lower side) is 0.81. Other measurement results are shown in Table 2.

[0198] (Comparative Example 8)

[0199] Except for the absence of a limiting member at the end of the hollow fiber membrane bundle on the side where the hollow part is sealed with gypsum, the use of 10,000 PVDF (polyvinylidene fluoride) hollow fiber membranes (manufactured by Asahi Kasei), the end face diameter of the second cylindrical member used being 168 mm, the inner diameter of the rectifier being 165 mm, and the average pore size of the hollow fiber membranes used being 0.1 μm, the inner diameter being 0.7 mm, and the outer diameter being 1.22 mm, the hollow fiber membrane module was manufactured in the same manner as Comparative Example 1, and its evaluation was conducted.

[0200] At this point, on the end face of the hollow opening of the hollow fiber membrane, the point corresponding to the thinnest part on the outer peripheral surface of the adhesive fixing part of the end face with the hollow opening of the hollow fiber membrane is taken as the upper vertex. When drawing a horizontal line that is orthogonal to the perpendicular line from the vertex toward the center of the end face and passes through the center, the number of hollow fiber membranes above the horizontal line is 4448, and the number of hollow fiber membranes below the horizontal line is 5552. That is, (number of hollow fiber membranes on the upper side) / (number of hollow fiber membranes on the lower side) is 0.80. Other measurement results are shown in Table 2.

[0201] (Comparative Example 9)

[0202] Except that a limiting member was not used at the end of the hollow fiber membrane bundle on the side where the hollow part was sealed with gypsum, 5600 PVDF (polyvinylidene fluoride) hollow fiber membranes (manufactured by Asahi Kasei) were used, the end face diameter of the second cylindrical member used was 168 mm, and the inner diameter of the rectifier tube was 165 mm, the hollow fiber membrane assembly was manufactured in the same manner as Comparative Example 1, and its evaluation was carried out.

[0203] At this point, on the end face of the hollow opening of the hollow fiber membrane, the point corresponding to the smallest thickness on the outer peripheral surface of the adhesive fixing part of the end face with the hollow opening of the hollow fiber membrane is taken as the upper vertex. When drawing a horizontal line that is orthogonal to the perpendicular line from the vertex toward the center of the end face and passes through the center, the number of hollow fiber membranes above the horizontal line is 2202, and the number of hollow fiber membranes below the horizontal line is 3398. That is, (number of hollow fiber membranes on the upper side) / (number of hollow fiber membranes on the lower side) is 0.65. In addition, in this hollow fiber membrane assembly, a gap can be seen in the length direction in a portion of the circumferential direction of the surface where the adhesive fixing part is bonded to the shell. Other measurement results are shown in Table 2.

[0204] (Comparative Example 10)

[0205] Except for the absence of a limiting member at the end of the hollow fiber membrane bundle on the side where the hollow part is sealed with gypsum, the use of 6600 PVDF (polyvinylidene fluoride) hollow fiber membranes (manufactured by Asahi Kasei), the end face diameter of the second cylindrical member being 168 mm, the inner diameter of the rectifier being 165 mm, and the use of a two-component thermosetting polyurethane resin (manufactured by TOSOH: KC-462 / N-4273 (trade name), viscosity after mixing for 10 minutes at 25°C: 5 Pa·s, viscosity after mixing for 30 minutes at 25°C: 850 Pa·s) as the potting material, the hollow fiber membrane module was manufactured in the same manner as Comparative Example 1, and its evaluation was conducted.

[0206] At this point, on the end face of the hollow opening of the hollow fiber membrane, the point corresponding to the thinnest part on the outer peripheral surface of the adhesive fixing part of the end face with the hollow opening of the hollow fiber membrane is taken as the upper vertex. When drawing a horizontal line that is orthogonal to the perpendicular line from the vertex toward the center of the end face and passes through the center, the number of hollow fiber membranes above the horizontal line is 2763, and the number of hollow fiber membranes below the horizontal line is 3837. That is, (number of hollow fiber membranes on the upper side) / (number of hollow fiber membranes on the lower side) is 0.72. Other measurement results are shown in Table 2.

[0207] (Comparative Example 11)

[0208] 11,500 PVDF (polyvinylidene fluoride) hollow fiber membranes (manufactured by Asahi Kasei) were bundled together at a length of 2.3 m, suspended vertically, and the lower end faces were cut off to align them. One side of the membrane bundle was sealed with plaster to enclose the hollow portion, and then inserted into a shell containing a second cylindrical member (end face diameter 218 mm) with an inner rectifier tube mounted on its inner side (216 mm inner diameter). The hollow fiber membranes used had an average pore size of 0.1 μm, an inner diameter of 0.7 mm, and an outer diameter of 1.22 mm.

[0209] Next, at the end of the hollow fiber membrane bundle on the first cylindrical member side, a columnar member is inserted at the position where a through hole is to be formed.

[0210] Next, the adhesive fixing container with the potting material inlet tube is fixed to the second cylindrical member of the housing 5, and the potting material is injected into the second cylindrical member of the housing by its own weight in the vertical direction. After the potting material has cured and stopped flowing, the housing 5 is flipped upside down, and the adhesive fixing container with the potting material inlet tube is fixed to the first cylindrical member of the housing, and the potting material is injected into the first cylindrical member of the housing by its own weight in the vertical direction. As the potting material, a two-component thermosetting epoxy resin (SANYU REC: A-751A / A-751B (trade name), viscosity after mixing for 10 minutes at 25°C: 1.2 Pa·s, viscosity after mixing for 30 minutes at 25°C: 2.0 Pa·s) is used. After the potting material has cured and stopped flowing, it is heated to 50°C in an oven and cured. In addition, the viscosity after 10 minutes and 30 minutes after mixing was measured using a type B viscometer.

[0211] Then, the end of the shell on the second cylindrical member side is cut off, making the total length of the shell 2.1m, thereby sealing the hollow opening on one side of the hollow portion before bonding. On the other hand, the columnar member is removed from the first bonding fixing part on the first cylindrical member side, thereby forming multiple through holes. Furthermore, the effective membrane length of this hollow fiber membrane assembly is 2m.

[0212] At this point, on the end face of the hollow opening of the hollow fiber membrane, the point corresponding to the thinnest part on the outer peripheral surface of the adhesive fixing part of the end face with the hollow opening of the hollow fiber membrane is taken as the upper vertex. When drawing a horizontal line that is orthogonal to the perpendicular line from the vertex toward the center of the end face and passes through the center, the number of hollow fiber membranes above the horizontal line is 5602 and the number of hollow fiber membranes below the horizontal line is 5898. That is, (number of hollow fiber membranes on the upper side) / (number of hollow fiber membranes on the lower side) is 0.95.

[0213] Although embodiments of the present invention have been described in detail above, various design changes can be made to the present invention without departing from its spirit.

[0214] [Table 1]

[0215]

[0216] [Table 2]

[0217]

[0218] Label Explanation

[0219] 1 Hollow fiber membrane module

[0220] 2 Hollow fiber membrane

[0221] 3 Hollow fiber membrane bundles

[0222] 5. Housing

[0223] 5a Annular concave-convex portion

[0224] 5b Outer region

[0225] 5c External Area

[0226] 7. Rectifier tube

[0227] 7a Flange

[0228] 8 Protective components

[0229] 10, 11 Cover

[0230] 10a, 11a piping

[0231] 12 Sanitary pads

[0232] 13 Fixtures

[0233] 20 First adhesive fixing part

[0234] 20a Through Hole

[0235] 21 Second adhesive fixing part

[0236] 21a End face of the second adhesive fixing part

[0237] 30 through hole

[0238] 41. Restricting Components

[0239] 50 Protrusion

[0240] 51 First cylindrical component

[0241] 52 Second cylindrical component

[0242] 53 Third cylindrical component

[0243] 52a nozzle

[0244] P potting material

[0245] S. Interface of potting material

[0246] S' Virtual Adhesion Interface

Claims

1. A hollow fiber membrane module, the hollow fiber membrane module comprising: The device comprises a cylindrical shell, a hollow fiber membrane bundle consisting of multiple hollow fiber membranes bound together, a first bonding and fixing part, and a second bonding and fixing part, wherein... The two ends of the hollow fiber membrane bundle are respectively housed in the cylindrical shell via the first adhesive fixing part and the second adhesive fixing part; The first adhesive fixing part and the second adhesive fixing part have a circular or elliptical end face perpendicular to the length direction of the shell, and the hollow part of the plurality of hollow fiber membranes is open on at least one of the end faces; In the first and / or second adhesive fixing portions of the end face having the hollow opening of the hollow fiber membrane, the region between the outer surface of the plurality of hollow fiber membranes and the inner surface of the housing, without the presence of restricting members that restrict the bias of the plurality of hollow fiber membranes, is filled with adhesive resin of a predetermined thickness in the length direction, and the hollow fiber membrane bundle is bonded and fixed to the housing. On the end face of the hollow opening of the hollow fiber membrane, the point corresponding to the portion with the smallest thickness in the length direction on the outer peripheral surface of the adhesive fixing portion having the end face is taken as the upper vertex. When drawing a horizontal line that is orthogonal to the perpendicular line from the upper vertex toward the center of the end face and passes through the center, the ratio of the number of hollow fiber membranes above the horizontal line to the number of hollow fiber membranes below the horizontal line, that is, the ratio of the number of hollow fiber membranes above the horizontal line to the number of hollow fiber membranes below the horizontal line, is 0.9 or more and 1.1 or less.

2. The hollow fiber membrane module according to claim 1, wherein, On the end face of the hollow opening of the hollow fiber membrane in the first bonding and / or the second bonding and fixing part, a first circle is defined as the smallest circle containing all the hollow fiber membranes present on the end face, a second circle is concentric with the first circle and has a diameter 2 cm smaller than the first circle, a first square is defined as the largest of the squares with sides of N cm located in the center of the second circle, and N is defined as the first square divided into 1 cm squares. 2 When there are two second squares, the ratio of the minimum to the maximum number of hollow fiber membranes contained in each second square is 0.4 or greater, where N is a natural number.

3. The hollow fiber membrane module according to claim 1 or 2, wherein, The diameter of the end face of the hollow section opening of the hollow fiber membrane is 150 mm or more.

4. The hollow fiber membrane module according to claim 1, wherein, The average of the thickness L1 of the adhesive fixing part at one intersection of the outer peripheral surface and the horizontal line and the thickness L2 of the adhesive fixing part at the other intersection of the outer peripheral surface and the horizontal line - the thickness L of the adhesive fixing part at the center of the end face. О It is 1mm or more and 12mm or less, and, The thickness L4 of the adhesive fixing part at the intersection of the perpendicular line from the upper vertex toward the center of the end face and the other point of the outer peripheral surface, and the thickness L3 of the adhesive fixing part at the upper vertex, are 3 mm or more and 12 mm or less.

5. The hollow fiber membrane module according to claim 1, wherein, The shell has a total length of 1m or more.

6. The hollow fiber membrane module according to claim 1, wherein, The total cross-sectional area of ​​all hollow fiber membranes / the internal cross-sectional area of ​​the shell, i.e., the filling rate of the hollow fiber membrane on the end face of the hollow part opening of the hollow fiber membrane, is 10% or more and 45% or less.

7. The hollow fiber membrane module according to claim 6, wherein, The total cross-sectional area of ​​all hollow fiber membranes / the internal cross-sectional area of ​​the shell, i.e., the filling rate of the hollow fiber membrane on the end face of the hollow part opening of the hollow fiber membrane, is 25% or more.

8. The hollow fiber membrane module according to claim 1, wherein, The resin constituting the first adhesive fixing part and / or the second adhesive fixing part of the end face having the hollow opening of the hollow fiber membrane is a single thermosetting resin with a D hardness of 60 or less at 25ºC according to JIS K7215.

9. The hollow fiber membrane module according to claim 8, wherein, The single thermosetting resin is a two-component curable thermosetting resin, wherein the viscosity of the thermosetting resin is 1 Pa·s or higher and 10 Pa·s or lower 10 minutes after the start of two-component mixing, and the viscosity exceeds 100 Pa·s after 30 minutes.

10. The hollow fiber membrane module according to claim 1, wherein, The multiple hollow fiber membranes are made of fluororesin.

11. The hollow fiber membrane module according to claim 1, wherein, On a virtual bonding interface, where the end face of the hollow opening of the hollow fiber membrane is virtually moved parallel to the center of the length direction towards the outer peripheral surface of the first bonding and / or the second bonding and fixing part, the thickness of the portion with the smallest thickness in the length direction is measured. The ratio of the total cross-sectional area of ​​all hollow fiber membranes to the internal cross-sectional area of ​​the shell is 20% or more and 50% or less. Furthermore, on this virtual bonding interface, taking the point corresponding to the portion with the smallest thickness in the length direction on the outer peripheral surface as the upper vertex, and drawing a horizontal line perpendicular to the vertical line from the upper vertex towards the center of the virtual bonding interface and passing through the center, the ratio of the number of hollow fiber membranes above the horizontal line to the number of hollow fiber membranes below the horizontal line, i.e., the ratio of the number of hollow fiber membranes above the horizontal line to the number of hollow fiber membranes below the horizontal line, is 0.85 or more and 1.15 or less.

12. The hollow fiber membrane module according to claim 1, wherein, In each hollow fiber membrane near the interface of the bonding and fixing part, there are protrusions where the potting material cures after permeating the hollow fiber membrane. The interface is the surface located on the opposite side of the end face of the adhesive fixing part.

13. The hollow fiber membrane module according to claim 12, wherein, The minimum length of the protrusion from the resin interface is 3 mm or more and 20 mm or less. The minimum length is the length of the shortest protrusion.

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