CN117180993A

CN117180993A - External pressure type hollow fiber membrane assembly

Info

Publication number: CN117180993A
Application number: CN202310666757.3A
Authority: CN
Inventors: 谷口超; 笠井重徳
Original assignee: Asahi Kasei Corp
Current assignee: Asahi Kasei Corp
Priority date: 2022-06-08
Filing date: 2023-06-06
Publication date: 2023-12-08
Also published as: JP2023180121A

Abstract

The purpose of the present invention is to provide an external pressure type hollow fiber membrane module which has good durability, excellent uniformity of pressure distribution and velocity distribution of fluid passing through the inside, and high production efficiency. Comprising the following steps: a bundle of hollow fiber membranes; a housing; a first adhesive fixing part for adhering and fixing the hollow fiber membranes to each other and the hollow fiber membrane bundles and the inner wall of the housing on the end side of the opening of the hollow fiber membrane; and a second adhesive fixing portion that adheres and fixes the hollow fiber membranes to each other and the hollow fiber membrane bundle to the inner wall of the housing on the closed end side of the hollow fiber membranes, and that has at least one through hole parallel to the longitudinal direction of the housing on the outer periphery of the hollow fiber membrane bundle, wherein an outer end surface of the second adhesive fixing portion is separated from an end surface (closed end surface) on the closed end side of the hollow fiber membranes, and a spacer is buried between the outer end surface of the second adhesive fixing portion and the end surface (closed end surface) on the closed end side of the hollow fiber membranes.

Description

External pressure type hollow fiber membrane assembly

[ field of technology ]

The invention relates to an external pressure type hollow fiber membrane component.

[ background Art ]

In a production line of ultrapure water used for manufacturing electronic/electric components such as semiconductors and display elements, final filtration is performed using a microfiltration membrane or an ultrafiltration membrane before ultrapure water manufactured using a microfiltration membrane, an ion exchange resin, a reverse osmosis filtration membrane, or the like is supplied to a point of use. In such final filtration, an external pressure type hollow fiber membrane module is mainly used, in which a bundle of hollow fiber membranes bundled up by a plurality of hollow fiber membranes is accommodated in a housing, water to be treated is supplied to the outside of the hollow fiber membranes, and the water is filtered to the inside (hollow portion) of the hollow fiber membranes.

For example, the external pressure type hollow fiber membrane module described in patent document 1 is provided so as to stand with its longitudinal direction being a vertical direction, and an upper nozzle for discharging filtered water and a lower nozzle for supplying water to be treated are disposed on the vertical direction upper side and the vertical direction lower side, respectively, so as to protrude in a direction orthogonal to the longitudinal direction of the housing. Both ends of the hollow part of the hollow fiber membrane are opened, and the end parts of the hollow fiber membrane bundles are adhered and fixed on the shell through the adhesive fixing layer. The water to be treated supplied from the lower nozzle is filtered from the outside to the inside (hollow portion) of the hollow fiber membrane in the housing, filtered water is discharged from both upper and lower ends of the housing, and discharged water is discharged from the upper nozzle.

The external pressure type hollow fiber membrane module described in patent document 2 is erected so that the longitudinal direction thereof is a vertical direction, and the nozzle for discharging water is disposed on the vertical direction side so as to protrude in a direction orthogonal to the longitudinal direction of the housing. One end of the hollow portion of the hollow fiber membrane is sealed, and the other end of the hollow portion is opened, and the hollow fiber membrane is disposed in the housing such that the sealed end is a lower side in the vertical direction and the opened end is an upper side in the vertical direction. In addition, only the open end side of the hollow fiber membrane bundle is adhesively fixed to the housing. The water to be treated supplied from the lower end of the housing is supplied to the outside of the hollow fiber membrane through a gap between the inner wall of the housing and a sealing portion sealing one end of the hollow fiber membrane, filtered inside (hollow portion) of the hollow fiber membrane, filtered water is discharged from the upper end of the housing, and discharged water is discharged from the nozzle.

In the external pressure type hollow fiber membrane module described in patent document 3, when water to be treated is supplied from the lower end of the housing, the water is filtered from the outside to the inside (hollow portion) of the hollow fiber membrane, the filtered water is discharged from the upper end of the housing, and the discharged water is discharged from the nozzle, as in patent document 2, but both ends (sealed end and open end) of the hollow fiber membrane bundle are adhesively fixed to the housing by the adhesive fixing portion. The water to be treated supplied from the lower end of the housing is supplied to the outside of the hollow fiber membrane through the through-hole provided in the adhesive fixing portion.

[ Prior Art literature ]

[ patent literature ]

[ patent document 1 ] Japanese patent application laid-open No. 2012-45453

Japanese patent application laid-open No. 2015-182056

Japanese patent application laid-open No. 2017-100105

[ invention ]

[ problem to be solved by the invention ]

In the external pressure type hollow fiber membrane module described in patent document 1, the water to be treated is supplied from the lower nozzle in a direction perpendicular to the hollow fiber membranes, and the water to be discharged is discharged from the upper nozzle in a direction perpendicular to the hollow fiber membranes, so that there is a problem in that: the vertical water pressure is applied to the hollow fiber membranes, and the stress is concentrated on the fixed portions at both ends of the hollow fiber membrane bundle, so that breakage is likely to occur at the ends (roots) of the hollow fiber membranes.

In the external pressure type hollow fiber membrane module described in patent document 2, the water to be treated is supplied in parallel to the hollow fiber membranes, so that the concentration of the stress caused by the supply of the water to be treated is relaxed. However, since the concentration of stress due to the discharge of the discharged water still exists, there is a problem in that: the maximum deflection of the discharged water in the vicinity of the discharge nozzle increases, and breakage is still likely to occur at the end (root) of the hollow fiber membrane.

In the external pressure type hollow fiber membrane module described in patent document 3, the water to be treated is supplied in parallel to the hollow fiber membranes, and both end portions of the hollow fiber membrane bundle are adhesively fixed to the housing, so that the concentration of stress caused by the supply of the water to be treated as described above is relaxed, and the maximum deflection amount is reduced. However, there is room for further improvement in order to reduce the pressure loss and to perform filtration efficiently.

Further, the external pressure type hollow fiber membrane module described in patent document 3 is applied to a filtration device or the like for removing endotoxin from raw water clarified by a pure water production apparatus, and therefore, in order to be used for final filtration of ultrapure water, it is necessary to further improve the hollow fiber membrane to be used.

Accordingly, an object of the present invention is to provide an external pressure type hollow fiber membrane module having excellent durability, excellent uniformity of pressure distribution and velocity distribution of fluid passing through the inside, and high production efficiency.

[ means for solving the problems ]

Namely, the present invention is as follows.

[1] An external pressure type hollow fiber membrane module, comprising: a bundle of hollow fiber membranes, each bundle being formed by bundling a plurality of hollow fiber membranes each having one end portion thereof closed and the other end portion thereof open;

a housing that is a cylindrical body having at least one nozzle on a side surface, and that houses the hollow fiber membrane bundles so that a closed end portion of the hollow fiber membrane and an open end portion of the hollow fiber membrane face both end sides in a longitudinal direction of the cylindrical body, respectively;

a first adhesive fixing portion that adheres and fixes the hollow fiber membranes to each other and the hollow fiber membrane bundle to the inner wall of the housing on an end side of the opening of the hollow fiber membrane; and

a second adhesive fixing portion that adheres and fixes the hollow fiber membranes to each other and the hollow fiber membrane bundle to the inner wall of the housing on the closed end side of the hollow fiber membranes, and that has at least one through hole parallel to the longitudinal direction of the housing on the outer periphery of the hollow fiber membrane bundle,

Wherein an outer end surface of the second adhesive fixing portion is separated from an end surface (closed end surface) of the hollow fiber membrane on the closed end side,

and a spacer is buried between the outer end surface of the second adhesive fixing portion and the end surface (closed end surface) of the hollow fiber membrane on the closed end side.

[2] The external pressure type hollow fiber membrane module according to [1], wherein a cross-sectional shape of the spacer in a direction orthogonal to a longitudinal direction of the housing is a shape selected from the group consisting of a ring (round), a lattice, a cross, a radial, a honeycomb, and a combination thereof.

[3] The external pressure type hollow fiber membrane module according to [1] or [2], wherein the spacer is composed of the same raw material as the second adhesive fixing portion.

[ Effect of the invention ]

According to the present invention, an external pressure type hollow fiber membrane module having excellent durability and excellent uniformity of pressure distribution and velocity distribution of fluid passing through the inside can be efficiently produced and provided.

[ description of the drawings ]

Fig. 1 is a longitudinal sectional view showing a brief structure of one embodiment of an external pressure type hollow fiber membrane module according to the present invention.

Fig. 2 is a cross-sectional view of the external pressure type hollow fiber membrane module shown in fig. 1 taken along the line A-A.

Fig. 3 (a) to (c) are perspective views showing one example of a spacer used in the external pressure type hollow fiber membrane module according to the present invention.

Fig. 4 (a) to (d) are perspective views showing one example of a spacer used in the external pressure type hollow fiber membrane module according to the present invention.

Fig. 5 (a) is a photograph showing one example of a spacer used in the external pressure type hollow fiber membrane module according to the present invention. (b) Is a photograph of the spacer of (a) provided in the external pressure type hollow fiber membrane module, as viewed from the outside in the longitudinal direction of the external pressure type hollow fiber membrane module.

Fig. 6 (a) is a photograph showing one example of a spacer used in the external pressure type hollow fiber membrane module according to the present invention. (b) Is a photograph of the spacer of (a) provided in the external pressure type hollow fiber membrane module, as viewed from the outside in the longitudinal direction of the external pressure type hollow fiber membrane module.

Fig. 7 (a) is a perspective view showing an example of a casting jig for forming the through-hole in the production of the external pressure type hollow fiber membrane module shown in fig. 1. (b) A perspective view of a cup for centrifugal casting attached to an end portion of a first tubular member for producing a first adhesive fixing portion when the external pressure type hollow fiber membrane module shown in fig. 1 is produced.

Fig. 8 is a schematic diagram showing an evaluation apparatus used for filtration evaluation of examples and comparative examples. (a) shows the evaluation device used in examples 1 and 2; (b) shows an evaluation device used in comparative example 1.

Fig. 9 is a diagram showing a simulation model used in example 3.

Fig. 10 is a diagram showing a simulation model used in comparative example 2.

Fig. 11 is a graph showing simulation results of deformation analysis of example 3. (a) is a perspective view; (b) is a cross-sectional view.

Fig. 12 is a graph showing simulation results of deformation analysis of comparative example 2. (a) is a perspective view; (b) is a cross-sectional view.

[ detailed description ] of the invention

Hereinafter, specific embodiments of the present invention (hereinafter, referred to as "the present embodiment") will be described in detail, but the present invention is not limited to the following description, and various modifications may be made within the scope of the gist thereof.

[ external pressure type hollow fiber Membrane Module ]

The external pressure type hollow fiber membrane module of the present embodiment is particularly suitable as a final filtration membrane module of ultrapure water used in cleaning at the time of manufacturing a silicon wafer, LSI, liquid crystal, or the like.

The constitution of an example of an external pressure type hollow fiber membrane module (hereinafter, also simply referred to as "hollow fiber membrane module") of the present embodiment will be described with reference to the drawings.

Fig. 1 is a longitudinal sectional view showing a schematic structure of one example of an external pressure type hollow fiber membrane module of the present embodiment. In fig. 1, the vertical direction is indicated by an arrow. In the following, the vertical direction shown in fig. 1 will be described as the vertical direction of the hollow fiber membrane module 1.

As shown in fig. 1, the hollow fiber membrane module 1 of the present embodiment includes: a bundle 3 of hollow fiber membranes formed by bundling a plurality of hollow fiber membranes 2; and a cylindrical housing 4 for housing the hollow fiber membrane bundle 3.

As the hollow fiber membrane 2, a reverse osmosis membrane, a nanofiltration membrane, an ultrafiltration membrane, and a microfiltration membrane can be used. The material of the hollow fiber membrane is not particularly limited, and examples thereof include polysulfone, polyethersulfone, polyacrylonitrile, polyimide, polyetherimide, polyamide, polyetherketone, polyetheretherketone, polyethylene, polypropylene, poly (4-methylpentene), ethylene-vinyl alcohol copolymer, cellulose acetate, polyvinylidene fluoride, ethylene-tetrafluoroethylene copolymer, polytetrafluoroethylene, and the like, and composite materials thereof may be used.

The hollow fiber membrane preferably has an inner diameter of 100 μm to 3000 μm and an outer diameter of 200 μm to 4000 μm; more preferably 200 μm to 2000 μm in inner diameter and 300 μm to 3000 μm in outer diameter; further preferably, the inner diameter is 400 μm to 1000 μm and the outer diameter is 500 μm to 2000. Mu.m. If the inner diameter and the outer diameter are in the above ranges, the filter has both permeation flux and durability, and is suitable for final filtration of ultrapure water.

The molecular weight cut-off of the hollow fiber membrane is preferably 6000 or more, more preferably more than 6000. If the molecular weight cut-off of the hollow fiber membrane is in the above range, it can be suitably used as a final filtration membrane module for ultrapure water used in cleaning at the time of production of silicon wafers, LSIs, liquid crystals and the like. Generally, although ultrapure water in which the number of particles mixed is small and the presence of particles is suppressed to be only small is desired as ultrapure water, it is preferable to use a hollow fiber membrane having a high water permeability with a molecular weight cut-off in the above range from the viewpoint of ensuring a large amount of water, because ultrapure water used for cleaning silicon wafers, LSI, liquid crystal and the like is used for the purpose of cleaning surface impurities of silicon wafers and the like. In filtration for removing endotoxin, water equivalent to distilled water used for washing of (dilution water of) an injection solution, a container of a pharmaceutical, or the like is obtained as filtered water, and therefore, a hollow fiber membrane having a molecular weight cut-off smaller than the above range is often used in preference to the permeation amount in terms of water quality, such that the endotoxin amount is not more than the detection limit (negative). On the other hand, in the filtration of ultrapure water for cleaning at the time of production of silicon wafers, LSI, liquid crystals, etc., a hollow fiber membrane having a high water permeability with a molecular weight cut-off in the above range is preferably used from the viewpoint of the removal object having a larger size than endotoxin and securing a large amount of water as described above.

The number of hollow fiber membranes depends on the size of the hollow fiber membranes and the inner cross-sectional area of the housing accommodating the hollow fiber membranes, but is preferably 5000 to 20000, more preferably 7000 to 15000, and even more preferably 9000 to 13000 from the viewpoint of collecting more filtered water.

Caps 8a and 8b for connecting pipes having a funnel-shaped cross section may be provided at both ends of the housing 4, and the caps 8a and 8b may be provided with openings (pipes) for connecting pipes. The covers 8a, 8b are fixedly mounted to the housing 4, for example by nuts 13.

Annular grooves are formed in the end surfaces of the covers 8a, 8b on the side of the case 4 and the end surfaces of the case 4 on the side of the covers 8a, 8b, and the O-ring 14 is sandwiched between the grooves. By this O-ring 14, both ends of the housing 4 and the covers 8a, 8b are sealed liquid-tightly. Specifically, the sealing structure by the O-ring 14 may be a structure described in, for example, japanese patent application laid-open No. 2017-39122.

It is preferable that the openings of the covers 8a and 8b and the pipes connected thereto are sealed and fixed by a gasket having the same inner diameter as the inner diameter of the openings of the covers 8a and 8 b. If the inner diameter of the opening of the cover 8a, 8b is the same as the inner diameter of the gasket, dust caused by stagnation of liquid and turbulence of the fluid in the corresponding portion of the fluid flowing inside can be suppressed.

The housing 4 is configured by joining a first tubular member 9a integrally formed with the nozzle 12a, a second tubular member 9b integrally formed with the nozzle 12b, and a straight tubular third tubular member 10 disposed between the first tubular member 9a and the second tubular member 9b to each other. The nozzles 12a and 12b are provided on the side portions of the end portion of the housing 4, respectively, and are provided so as to protrude in a direction orthogonal to the longitudinal direction of the housing 4. The nozzle 12a is a nozzle that discharges water during the outside pressure filtration process. Since the nozzle 12b is not particularly used in the hollow fiber membrane module 1 of the present embodiment, the opening thereof is sealed.

The hollow fiber membrane module 1 of the present embodiment is erected so that the longitudinal direction thereof is the vertical direction, and is provided such that the nozzle 12a is disposed on the vertical direction upper side and the nozzle 12b is disposed on the vertical direction lower side.

As shown in fig. 1, a first rectifying cylinder 11a and a second rectifying cylinder 11b may be mounted between both end portions of the hollow fiber membrane bundle 3 and the first tubular member 9a and the second tubular member 9b, respectively.

The first rectifying cylinder 11a and the second rectifying cylinder 11b are formed in a cylindrical shape, the first rectifying cylinder 11a is provided between the opening on the inner side surface side of the housing 4 of the upper nozzle 12a and the hollow fiber membrane bundle 3, and the second rectifying cylinder 11b is provided between the opening on the inner side surface side of the housing 4 of the lower nozzle 12b and the hollow fiber membrane bundle 3, and is provided so as to surround the outer circumference of the hollow fiber membrane bundle 3, respectively.

The first rectifying cylinder 11a and the second rectifying cylinder 11b are provided to maintain the interval between the hollow fiber membrane bundle 3 and the inner wall of the housing 4 in the vicinity of the nozzles 12a and 12 b.

The upper end of the first rectifying cylinder 11a may be adhesively fixed in a first adhesive fixing portion 5a described later, and the lower end of the second rectifying cylinder 11b may be adhesively fixed in a second adhesive fixing portion 5b described later.

By attaching the first rectifying cylinder 11a and the second rectifying cylinder 11b to both end portions of the housing 4, in the production of the hollow fiber membrane module 1, when the hollow fiber membrane bundle 3 is adhesively fixed in the housing 4 by centrifugal adhesion described later, the hollow fiber membrane bundle 3 can be prevented from falling down during centrifugation.

First and second adhesive fixing portions 5a and 5b for adhering and fixing the hollow fiber membranes 2 to each other and the hollow fiber membrane bundle 3 to the inner wall of the housing 4 by a potting material are formed at both end portions of the hollow fiber membrane bundle 3.

By bonding and fixing the both ends of the hollow fiber membrane bundle 3 in this manner, the maximum deflection of the hollow fiber membrane bundle 3 is reduced and stress concentration is relaxed, compared with the case where only one end is bonded and fixed, and therefore, breakage of the hollow fiber membranes 2 can be prevented, and a hollow fiber membrane module having excellent durability can be obtained.

As the potting material, a polymer material such as an epoxy resin, a vinyl ester resin, a polyurethane resin, an unsaturated polyester resin, an olefin polymer, a silicone resin, and a fluorine-containing resin is preferable. These polymer materials may be used alone or in combination of two or more.

The first adhesive fixing portion 5a and the second adhesive fixing portion 5b made of these potting materials are required to have pressure resistance capable of withstanding a pressure difference between the primary side and the secondary side due to pressurization during filtration, and for this reason, preferably have moderate hardness. On the other hand, in order to reliably prevent breakage of the hollow fiber membrane 2 due to the flow of the fluid during physical cleaning for a longer period of time, it is desirable to use a potting material having an appropriate softness. Therefore, in order to provide sufficient pressure resistance required for use and to reliably prevent film breakage, it is preferable to use a potting material having a hardness of 80D to 50A in the use temperature range.

The hardness as referred to herein means a value which is displayed after 10 seconds when the Durometer type D or a is pressed against a material surface having a substantially smooth surface in accordance with JIS K6253. If the value exceeds 80D, the above-mentioned film breakage may occur, and, if it is less than 50A, the pressure resistance may be insufficient.

A region (hereinafter referred to as "outer region") into which the treatment target liquid flows is formed outside the hollow fiber membrane bundle 3 between the first adhesive fixing portion 5a and the second adhesive fixing portion 5b formed at both end portions of the hollow fiber membrane bundle 3.

In addition, as shown in fig. 1, when the hollow fiber membrane module 1 is erected in the vertical direction, at least one through hole 6 is formed in the second adhesive fixing portion 5b located on the lower side. Here, fig. 2 is a sectional view of the hollow fiber membrane module 1 shown in fig. 1 taken along a line A-A.

The through hole 6 is formed in parallel along the longitudinal direction of the housing 4, and communicates the outer region with the inside of the cover 8 b. As shown in fig. 2, the through-hole 6 is preferably provided in a second adhesive fixing portion 5b between a protective member 7 described later and the inner wall of the housing 4, and is disposed adjacent to the outer peripheral surface of the hollow fiber membrane bundle 3.

The shape of the through hole 6 is not particularly limited, and examples thereof include a shape of a cross section (opening shape) in a direction orthogonal to the longitudinal direction of the housing 4, such as a circle, an ellipse, a polygon, a partial arc shape having a width, and a circular ring shape.

If the opening shape of the through-holes 6 is a partial circular arc having a width, the opening area of the through-holes 6 can be made larger while accommodating a plurality of hollow fiber membranes 2 per unit volume, as compared with the case where the opening shape is a circle, an ellipse, a polygon, or the like, and the number of hollow fiber membranes 2 per unit volume and the amount of water to be treated supplied to the hollow fiber membrane bundle 3 are balanced to have a larger value, so that filtration can be performed more efficiently.

In the present disclosure, the partial arc having the width may be a partial arc of a concentric circle centered on the center of the hollow portion (region divided by the inner wall of the housing) of the housing 4 as shown in fig. 2, and may be a shape extending in the circumferential direction of the housing, for example, a shape in which the contour line constituting the shape is wavy or zigzag. The shape of the end of the partial arc is not particularly limited, and may be, for example, a shape with rounded corners as shown in fig. 2.

Regarding the opening shape of the through hole 6, for example, in the case where four through holes 6 are provided, the center angle of the partial circular arc centering on the center of the hollow portion of the housing 4 is preferably 45 ° to 85 °, more preferably 60 ° to 80 °, still more preferably 70 ° to 80 °.

The width of the partial arc (the width in the radial direction of the hollow portion of the housing) is preferably 0.05r to 0.25r, more preferably 0.07r to 0.20r, and even more preferably 0.09r to 0.12r, with the radius of the hollow portion of the housing being r.

The number of the through holes 6 is not particularly limited, but is preferably plural, more preferably 2 to 8, and even more preferably 3 to 6, from the viewpoint of setting the total sum a of opening areas described later to a value as large as possible.

When a plurality of through holes 6 are provided, the area of each opening (cross section in the direction orthogonal to the longitudinal direction of the housing 4) is preferably substantially the same (within a range of ±5%).

In the case where there are a plurality of through holes 6, the through holes 6 are preferably provided at equal intervals on the circumference of the circle formed by the openings. In the case where there are an even number of through holes 6, each through hole 6 is preferably point-symmetrical about the center of the hollow portion of the housing 4.

In the second adhesive fixing portion 5b, the outer end face 5e of the second adhesive fixing portion 5b is separated from the end face (closed end face) 2e of the closed end portion of the hollow fiber membrane 2 buried in the second adhesive fixing portion 5 b. As shown in fig. 1, the outer end surface 5e of the second adhesive fixing portion 5b is an end surface on the outer side (lower side in fig. 1) in the longitudinal direction of the housing 4.

By separating the outer end surface 5e of the second adhesive fixing portion 5b from the closed end surface 2e of the hollow fiber membrane 2, it becomes easier to inject the potting material into the hollow portion of the hollow fiber membrane 3 at the time of adhesive fixing of the hollow fiber membrane bundle 3 in the production of the hollow fiber membrane module 1, and thus it becomes difficult to generate an initial defect such as a defective seal, so that it is possible to improve the production efficiency and to provide a large amount of products at a lower cost.

The separation distance between the outer end face 5e of the second adhesive fixing portion 5b and the closed end face 2e of the hollow fiber membrane 2 is preferably 1mm to 10mm, more preferably 3mm to 8mm, and even more preferably 3mm to 5mm, from the viewpoint of ensuring a gap for the potting material to wrap around a predetermined portion at the time of adhesive fixing.

The separation distance is a value obtained by measuring, for 20 or more hollow fiber membranes 2, the distance between the closed end face 2e of the hollow fiber membrane 2 and the outer end face 5e of the second adhesive fixing portion 5b in the longitudinal direction (up-down direction in fig. 1) of the housing 4, and averaging the measured distances.

A spacer other than the hollow fiber membrane 2 is provided between the outer end surface 5e of the second adhesive fixing portion 5b and the closed end surface 2e of the hollow fiber membrane 2 so that a part or the whole of the spacer is embedded in the second adhesive fixing portion 5 b. When a spacer is provided between the outer end face 5e of the second adhesive fixing portion 5b and the closed end face 2e of the hollow fiber membrane 2, the second adhesive fixing portion 5b becomes firm, and is excellent in pressure resistance against a pressure difference between the primary side and the secondary side due to pressurization at the time of filtration, and the hollow fiber membrane bundle 3 is firmly supported, so that breakage of the hollow fiber membrane 2 can be reliably prevented for a long period of time, and a hollow fiber membrane module having good durability can be obtained.

Examples of the shape of the spacer include the spacer 15 shown in fig. 1 and various shapes shown in fig. 3 to 6.

The spacer may have a portion exposed from the second adhesive fixing portion 5b by embedding only a part of the second adhesive fixing portion 5b, or may be entirely embedded in the second adhesive fixing portion 5b, but is preferably entirely embedded from the viewpoint of surface smoothness of the outer end surface 5e of the second adhesive fixing portion 5 b.

The distance from the closed end face 2e of the hollow fiber membrane 2 to the spacer is not particularly limited, but is preferably 0mm to 10mm, more preferably 0mm to 8mm, still more preferably 0mm to 5mm. If the distance from the closed end face 2e of the hollow fiber membrane 2 to the spacer is within the above range, the hollow fiber membrane bundle 3 can be firmly and uniformly supported, and breakage of the hollow fiber membrane 2 can be reliably prevented for a long period of time, and the hollow fiber membrane module tends to have good durability.

In addition, the distance from the closed end face 2e of the hollow fiber membrane 2 to the spacer is the minimum value of the distance in the longitudinal direction (up-down direction in fig. 1) of the housing 4 from the closed end face 2e of the hollow fiber membrane 2 to the spacer.

The distance from the outer end face 5e of the second adhesive fixing portion 5b to the spacer is not particularly limited, but is preferably 0mm to 10mm, more preferably 0mm to 8mm, still more preferably 0mm to 5mm. If the distance from the outer end face 5e of the second adhesive fixing portion 5b to the spacer is within the above range, the hollow fiber membrane module tends to have excellent pressure resistance against the pressure difference between the primary side and the secondary side due to pressurization during filtration, and thus has excellent durability.

The distance from the outer end surface 5e of the second adhesive fixing portion 5b to the spacer is the minimum value of the distance from the outer end surface 5e of the second adhesive fixing portion 5b to the spacer in the longitudinal direction (up-down direction in fig. 1) of the housing 4.

The shape of the spacer 15 is not particularly limited, but from the viewpoint of firmly and uniformly supporting the hollow fiber membranes 2 by the second adhesive fixing portions 5b, the cross-sectional shape of the housing 4 in the direction orthogonal to the longitudinal direction (up-down direction in fig. 1) is preferably any one of a circle, a lattice, a cross, a radial shape, a honeycomb shape, and a combination thereof.

In addition, from the viewpoint of making the second adhesive fixing portion 5b stronger and supporting the hollow fiber membranes 2 more uniformly, it is preferable that the circumscribed circle of the spacer 15 having a cross-sectional shape in the direction orthogonal to the longitudinal direction of the housing 4 (up-down direction in fig. 1) be substantially identical to the circumscribed circle of the hollow fiber membrane bundle 3 having a cross-sectional shape in the direction orthogonal to the longitudinal direction of the housing 4 (up-down direction in fig. 1).

The "substantially uniform" includes not only the case of complete uniformity but also the case where the difference between the diameter of the circumscribed circle of the spacer 15 and the diameter of the circumscribed circle of the hollow fiber membrane bundle 3 is less than ±10% of the diameter of the circumscribed circle of the hollow fiber membrane bundle 3.

The number of spacers 15 is not particularly limited, and may be 1 or a plurality of spacers.

Fig. 3 and 4 show an example of a spacer used in the external pressure type hollow fiber membrane module of the present embodiment.

Fig. 5 and 6 show photographs (fig. 5 (a) and 6 (a)) of an example of a spacer used in the external pressure type hollow fiber membrane module of the present embodiment and photographs (fig. 5 (b) and 6 (b)) of a state in which the spacer is provided in the external pressure type hollow fiber membrane module (taken from the outside in the longitudinal direction of the external pressure type hollow fiber membrane module).

The material of the spacer 15 is not particularly limited, and examples thereof include polymer materials such as epoxy resin, vinyl ester resin, urethane resin, unsaturated polyester resin, olefin polymer, silicone resin, and fluorine-containing resin. These polymer materials may be used alone or in combination of two or more.

The spacer 15 may be made of the same material as the second adhesive fixing portion 5b (potting material) (see fig. 5 a and 5 b), or may be made of a different material, but is preferably made of the same material from the viewpoint of preventing peeling inside the second adhesive fixing portion 5 b. In the case of a material different from the second adhesive fixing portion 5b, it is desirable to cut out and stack a plurality of protective members 7 on a net to be described later, and the like, to be the same material as other constituent members (see fig. 6 (a) and 6 (b)).

The ratio (a/S) of the sum a of the opening areas of the through holes 6 to the area S obtained by subtracting the area of the region divided by the outer peripheral surface of the protection member 7 (hereinafter, also referred to as the "inner occupied area of the protection member 7") from the area of the region divided by the inner wall of the housing 4 (hollow portion) (hereinafter, also referred to as the "inner cross-sectional area of the housing 4") in the cross section orthogonal to the longitudinal direction of the housing 4 is preferably 0.2 to 0.7, more preferably 0.3 to 0.6, and further preferably 0.4 to 0.5. If the a/S is within the above range, the amount of water to be treated supplied to the hollow fiber membrane bundle 3 through the through-holes 6 increases, and filtration can be performed efficiently.

The hollow portion of each hollow fiber membrane 2 on the side where the through hole 6 is provided is closed by the second adhesive fixing portion 5b, and the hollow portion of each hollow fiber membrane 2 on the opposite side to the side where the through hole 6 is formed is opened. In the filtering process, the water to be treated flows in from the opening of the cover 8b, and is supplied to the outside region through the through hole 6. Then, the water to be treated supplied to the outer region permeates from the outer surface of each hollow fiber membrane 2, the filtered water passing through the hollow portion of each hollow fiber membrane 2 is discharged from the opening of the cap 8a, and the discharged water is discharged from the nozzle 12 a.

The hollow fiber membrane module 1 further includes a protective member 7 that is provided so as to cover the entire circumference of the outer circumferential surface of the hollow fiber membrane bundle 3 in a state of being in close contact with the outer circumferential surface. The protective member 7 may be provided in at least one of an end region having at least a predetermined length from the first adhesive fixing portion 5a toward the second adhesive fixing portion 5b and an end region having at least a predetermined length from the second adhesive fixing portion 5b toward the first adhesive fixing portion 5a, and may be disposed so as to cover the entire length of the hollow fiber membrane bundle 3 from the first adhesive fixing portion 5a to the second adhesive fixing portion 5b, as shown in fig. 1.

The protective member 7 is preferably flexible, and examples of the material thereof include polyolefin such as PE (polyethylene) and PP (polypropylene), fluororesin such as PFA (tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer), FEP (tetrafluoroethylene-hexafluoropropylene copolymer (4.6 fluorinated)), ETFE (tetrafluoroethylene-ethylene copolymer), and super engineering resin such as polysulfone, polyethersulfone, and polyphenylsulfone.

The protective member 7 is particularly preferably a member formed in a tubular shape as a net-like member. When a member formed into a tubular shape instead of a mesh-like member is used as the protective member 7, it is desirable that the protective member be provided only at both ends of the hollow fiber membrane bundle 3 or only at one end of the hollow fiber membrane bundle 3, not at substantially the entire outer peripheral surface of the hollow fiber membrane bundle 3, so as not to reduce the filtration efficiency.

In the case where the protective member 7 is a net-like member, the wire diameter of the net is preferably 0.2mm to 1.5mm, more preferably 0.4mm to 1.2mm, still more preferably 0.5mm to 1.0mm. If the wire diameter is within the above range, the hollow fiber membrane bundle 3 deforms with deformation such as expansion and bending due to water flow, and the net itself is not easily broken.

The shape of the opening of the mesh-like protection member 7 is not particularly limited, and examples thereof include a triangle, a quadrangle (diamond, square, rectangle, parallelogram, etc.), a hexagon, and the like.

The cross section of the net wires constituting the net is not particularly limited, and may be any of a polygon such as a circle, triangle, quadrangle, and the like, an ellipse, and the like.

In order to efficiently supply a large amount of water to be treated to the hollow fiber membrane bundle 3, the opening ratio of the net-like protective member 7 is preferably 40% to 90%, more preferably 50% to 80%, and still more preferably 60% to 70%.

The aperture ratio is a ratio obtained from the area of the portion where no net wire exists projected in a plan view.

Both ends of the protection member 7 are located in the first and second adhesive fixing portions 5a and 5b, respectively, and are fixed by the first and second adhesive fixing portions 5a and 5 b.

The protective member 7 is preferably provided in a state of being in close contact with the outer peripheral surface of the hollow fiber membrane bundle 3 at least one end portion of the hollow fiber membrane bundle 3. Specifically, the end portions are a first end portion region R1 including a boundary between the second adhesive fixing portion 5b and the outer region and a region extending from the boundary to the outer region by a predetermined length L1, and a second end portion region R2 including a boundary between the first adhesive fixing portion 5a and the outer region and a region extending from the boundary to the outer region by a predetermined length L2.

The length L1 from the boundary in the first end region R1 is desirably 5cm and more. In the hollow fiber membrane module 1 of the present embodiment, as described above, the discharged water is discharged from the nozzle 12a, but when the discharged water is discharged from the nozzle 12a, attractive force acts on the hollow fiber membranes 2 in the vicinity of the nozzle 12a, and the tendency of breakage increases, and the hollow fiber membranes 2 may be easily broken. Therefore, the length L2 from the boundary in the second end region R2 is desirably a length in which the lower end of the second end region R2 is located further below the lower end of the opening on the inner side surface side of the housing 4 of the nozzle 12 a. This can suppress deformation of the hollow fiber membranes 2 in the vicinity of the nozzle 12a due to the suction force generated when the water is discharged from the nozzle 12a, and can further suppress breakage of the hollow fiber membranes 2.

Here, the term "the state where the protective member 7 is in close contact with the outer peripheral surface of the hollow fiber membrane bundle 3" means that when the length of the inner periphery of the protective member 7 is L, the number of the hollow fiber membranes 2 in contact with the protective member 7 is m, the outer diameter of the hollow fiber membranes 2 filled in the protective member 7 is d, the md/L is the contact ratio, and the md/L is 0.90 or more. The higher the adhesion ratio, the more preferable, and the more preferable is that the md/L is 0.95 or more. In the case where the inner diameter of the protective member 7 is sufficiently larger than the outer diameter of the hollow fiber membrane 2, in theory, if the maximum number of hollow fiber membranes 2 in the outermost peripheral portion that can be in contact with the protective member 7 is M, l≡md is established, and hence an approximation of Md/l≡md/md=m/M is established.

The contact between the protective member 7 and the hollow fiber membranes 2 means that the hollow fiber membranes 2 disposed on the outermost peripheral portion of the hollow fiber membrane bundle 3 and the protective member 7 are in contact with each other at least at one point or more in the thickness direction of the first adhesive fixing portion 5a and the second adhesive fixing portion 5b (the longitudinal direction of the hollow fiber membranes 2).

In the hollow fiber membrane module 1 of the present embodiment, when the sum of the opening areas of the through holes 6 is a, the sum of the opening areas of the hollow portions of the hollow fiber membranes 2 is B, and the opening areas of the opening portions of the covers 8a, 8B are C, the relationship of A, B, C is preferably 0.5< a/B <1.5, and 0.5< C/B <1.5. If a/B and C/B are within the above ranges, concentration of stress to a specific portion is reduced, and uniformity of pressure distribution and velocity distribution of fluid passing through the inside of the hollow fiber membrane module 1 tends to be improved. This reduces the pressure loss, and more filtered water can be collected efficiently.

More preferably, A/B is 0.8< A/B <1.2, still more preferably 0.9< A/B <1.1. Further, C/B is more preferably 0.8< C/B <1.2, still more preferably 0.9< C/B <1.1.

In the hollow fiber membrane module of the present embodiment, the filtration water amount (permeate water amount) of each module is preferably 10m ³ And/h and above, more preferably 12m ³ Preferably/h and above, more preferably 16m ³ And/h and above. If the amount of filtered water per unit is in the above range, it can be suitably used as a final filtration membrane unit for ultrapure water used in cleaning at the time of production of silicon wafers, LSIs, liquid crystals and the like.

The hollow fiber membrane module according to the present embodiment may include a baffle plate or the like for adjusting the flow of the feed water, in addition to the above-described members, as needed.

[ method for producing external pressure type hollow fiber Membrane Module ]

The method of manufacturing the external pressure type hollow fiber membrane module according to the present embodiment will be described by taking the method of manufacturing the external pressure type hollow fiber membrane module 1 shown in fig. 1 as an example.

As a method for producing the external pressure type hollow fiber membrane module 1, for example, the following methods are mentioned: the first rectifying tube 11a and the second rectifying tube 11b are mounted on the housing 4, after the hollow fiber membrane bundle 3 and the spacer 15 covered with the protective member 7 are inserted into the housing 4, a casting jig having at least one convex portion having an arc-shaped cross section parallel to the substantially disk-shaped surface is mounted on the substantially disk-shaped surface so that the convex portion is located between the protective member 7 and the housing 4, and after the gap between the protective member 7 and the housing 4 is filled with the potting material, the casting jig is removed, whereby the outer peripheral surface of the hollow fiber membrane bundle 3 is brought into close contact with the protective member 7, and at least one through hole 6 having an arc-shaped cross section in a direction orthogonal to the longitudinal direction of the housing 4 is opened outside the protective member 7.

More specifically, first, a predetermined number of hollow fiber membranes 2 are bundled to prepare a hollow fiber membrane bundle 3. At this time, the openings of the sealing side ends of the hollow fiber membranes 2 of the hollow fiber membrane bundle 3 may be sealed in advance with a sealing material.

Next, the first tubular member 9a and the second tubular member 9b are joined to both ends of the third tubular member 10 to form the housing 4, and the first rectifying cylinder 11a and the second rectifying cylinder 11b are attached to form the assembly housing main body. Then, the outer peripheral surface of the hollow fiber membrane bundle 3 is covered with the protective member 7, and the hollow fiber membrane bundle 3 covered with the protective member 7 is inserted into the housing 4 so that the end on the sealing side becomes the second cylindrical member 9b side.

Then, a cup-shaped bonding jig (for example, fig. 7 (b)) is attached to the first cylindrical member 9a side, the spacer 15 is disposed at a predetermined position on the second cylindrical member 9b side, and then a casting jig (for example, fig. 7 (a)) having at least one circular arc-shaped convex portion in a cross section parallel to the substantially circular-disk-shaped surface is attached to the substantially circular-disk-shaped surface so that the convex portion of the casting jig is interposed between the outer peripheral surface of the hollow fiber membrane bundle 3 surrounded by the protective member 7 and the second cylindrical member 9b, and the first cylindrical member and the second cylindrical member are liquid-tightly bound to the respective bonding jigs by a known method. At this time, the outer peripheral surface of the hollow fiber membrane bundle 3 is brought into close contact with the protective member 7 by inserting the arcuate portion of the jig (for example, fig. 7 (a)) having the convex portion. The convex portion of the casting jig is also a portion of the mold that serves as the through-hole 6, and as described later, the through-hole 6 is formed by removing the casting jig after the potting material is cured.

As necessary, as the offset regulating member, a cross plate (two plates are joined or integrally molded so that the cross section in the direction orthogonal to the height direction is cross-shaped) may be provided in the hollow fiber membrane bundle 3 so that the height direction of the cross plate is the longitudinal direction of the hollow fiber membrane bundle 3. The cross plate is preferably of the same composition as the potting material.

Next, the first adhesive fixing portion 5a and the second adhesive fixing portion 5b are formed by injecting a potting material into both end portions of the case 4. At this time, the opening of the hollow portion of the hollow fiber membrane bundle 3 on the second cylindrical member 9b side is closed with a potting material. Thereafter, the casting jig is removed to form the through-hole 6.

The bonding and fixing of the hollow fiber membrane bundles 3 and the housing 4 can be performed by centrifugal bonding, which bonds the housing 4 containing the hollow fiber membrane bundles 3 while rotating the housing 4 in the horizontal direction with the nozzles 12a and 12b directed upward in the vertical direction, or by static bonding; the stationary bonding is to arrange the longitudinal direction of the case 4 in the vertical direction and to inject the potting material from the lower end of the case 4.

Centrifugal bonding can bond both ends of the hollow fiber membrane bundle 3 at the same time, and since the coating layer on the outer surface of the hollow fiber membrane bundle 3 can be uniform, it is difficult to cause membrane breakage, but high equipment investment and electric power for high-speed rotation are required. Here, in order to separate the outer end surface of the second adhesive fixing portion 5b from the end surface (closed end surface) of the hollow fiber membrane 2 on the closed end side, it is necessary to adhere the outer end surface of the second adhesive fixing portion 5b and the closed end surface of the hollow fiber membrane 2 while ensuring a gap therebetween. Unlike the present embodiment, in the external pressure type hollow fiber membrane module 1 in which the spacer is not used, it is difficult to perform centrifugal bonding in a state where the above gap is ensured, and therefore, for example, the following method is required: the method of holding the hollow fiber membrane bundle 3 in the housing 4 so that the hollow fiber membrane bundle 3 is not moved by centrifugal force and then performing centrifugal bonding, the method of holding the hollow fiber membrane bundle 3 in an exposed state without holding it in the housing 4 and performing centrifugal bonding (first time), and then further performing centrifugal bonding (first time) after holding it in the housing 4, and the like. However, in the present embodiment, since the spacer is interposed between the hollow fiber membrane bundle 3 and the casting jig, the outer end surface of the second adhesive fixing portion 5b can be easily formed in a state of being separated from the closed end surface of the hollow fiber membrane 2.

On the other hand, since the stationary bonding requires side-by-side bonding (bonding of the first bonding fixing portion 5a and bonding of the second bonding fixing portion 5b are performed 2 times in total), the time required for bonding is increased compared with the centrifugal bonding, but large equipment investment is not required, and the stationary bonding can be performed with a simple jig. Here, in order to separate the outer end surface of the second adhesive fixing portion 5b from the closed end surface of the hollow fiber membrane 2, it is necessary to adhere the outer end surface of the second adhesive fixing portion 5b and the closed end surface of the hollow fiber membrane 2 while ensuring a gap therebetween, as described above. Accordingly, as a method of bonding efficiently by standing bonding, for example, there is a method of cutting the end portion of the hollow fiber membrane bundle 3 after opening the hollow portion of the hollow fiber membrane 2, as described later, and thus, even if the end portion of the hollow fiber membrane bundle 3 on the first bonding and fixing portion 5a side is firmly gripped, the hollow fiber membrane bundle 3 is accommodated in the case 4, the end portion on the first bonding and fixing portion 5a side of the hollow fiber membrane bundle 3 is firmly gripped, the hollow fiber membrane bundle 3 is brought into a floating state (a state in which the first bonding and fixing portion 5a side is directed upward and the hollow fiber membrane bundle 3 is lifted from above), the spacer 15 is provided under the hollow fiber membrane bundle 3, and the bonding and fixing of the second bonding and fixing portion 5b are performed, and then the bonding and fixing of the first bonding and fixing portion 5a are performed.

After the potting material is cured, the curing may be accelerated by heating with an oven or the like as necessary.

Next, after confirming that the potting material in the case 4 is cured, the first tubular member side 9a opens the hollow portion of the hollow fiber membrane bundle 3 by removing the adhesive fixing portion forming container and the sealing material (for example, by cutting off the end portion of the first adhesive fixing portion 5 a). The second tubular member 9b side can form the through hole 6 having an arc-shaped opening by removing the adhesive fixing portion forming container and the casting jig.

Finally, the covers 8a and 8b were attached to both end portions of the housing 4 to which the hollow fiber membrane bundles 3 were bonded via the O-rings 14, and after the hollow fiber membrane bundles were fastened and fixed by the nuts 13, it was confirmed that the hollow fiber membrane modules 1 were manufactured as desired by performing leak inspection, test run, and the like.

[ example ]

The present embodiment will be described below with reference to specific examples and comparative examples, but the present embodiment is not limited to these examples.

The measurement method and test method used in examples and comparative examples will be described below.

(1) Leak check

The external pressure type hollow fiber membrane modules of examples and comparative examples were subjected to leak inspection as follows.

That is, after removing the covers (two in comparative example 1 and one in comparative example 1) on the side where the filtered water was collected, the hollow fiber membrane module was immersed in a water tank to fill the inside with water. Then, the lid (nozzle in comparative example 1) on the side to which the feed water was supplied was sealed, and an air pressure of 0.3[ MPa ] was applied from the water discharge nozzle. The filtration water collection side end surfaces (two end surfaces and one end surface in comparative example 1) of the hollow fiber membrane were observed, and the occurrence of leakage was examined based on the presence or absence of generation of open bubbles from the hollow portion.

(2) Deformation analysis

Regarding the examples and comparative examples, the deformation amount of the second adhesive fixing portion was measured by simulation software. As the simulation software, the stress analysis software "midas-NFX" manufactured by midas corporation was used.

The boundary conditions are as follows.

Constraint: completely restraining the outer peripheral surface of the second adhesive fixing portion (the surface that is originally adhered and fixed to the housing)

Contact of the parts with each other: type of surface contact, welding

Stress: applying 0.5MPa as pressure only to the outer end face of the second adhesive fixing portion

Input physical property values (flexural modulus): as described in "(3) bending test" described later, a test piece of a predetermined shape was cut out from each constituent part, and an average value of values (n=5) obtained by the 3-point bending test was calculated and used as flexural modulus (MPa)

(3) Bending test

Before the deformation analysis of "(2), 3-point bending test was performed on both a single material portion (including a spacer made of the same material as the potting material) of the second adhesive fixing portion and a film bundle containing portion (an area of the hollow fiber film bundle which occupies approximately 70% of its outer diameter in a cross section perpendicular to the longitudinal direction of the housing) of the second adhesive fixing portion, in which the hollow fiber film bundle occupies a large part, to obtain a bending elastic modulus (MPa) required for simulation.

Cutting 7 test pieces with the width of 12.7mm, the thickness of 3.2mm and the length of 60mm and above from a single material part; in the film bundle containing portion, 7 test pieces 15mm wide, 10mm thick, 60mm long and above were cut out, and the measurement was performed under the following equipment and conditions.

Measurement instrument: autograph AGS-X manufactured by Shimadzu corporation

Distance between fulcrums: 18.6mm

Fulcrum movement speed: 1 mm/min

Among the 7 pieces of data, an average value of data of n=5 excluding the minimum value and the maximum value was used. The values are as follows.

Single material portion (including spacer): 2800MPa

The membrane bundle contains parts: 75MPa of

Example 1 (use case)

Manufacturing of external pressure hollow fiber membrane module

An external pressure type hollow fiber membrane module was manufactured as follows (see fig. 1).

11600 polysulfone hollow fiber membranes (manufactured by Asahi chemical Co., ltd.) were bundled to form a bundle of hollow fiber membranes, and the bundle was inserted into a polyethylene net (wire diameter 0.45mm, opening ratio 55%, corresponding to a protective member) formed in a tubular shape having an inner diameter of 138 mm. The hollow fiber membrane bundles inserted into the mesh were inserted into a housing having first and second tubular members (inner diameter: 168 mm) and a third tubular member (inner diameter: 154 mm), and first and second rectifying cylinders (inner diameter: 140 mm) were respectively mounted on the inner sides of the first and second tubular members. The first tubular member has a nozzle for discharging water having an inner diameter of 40mm, and the second tubular member has a nozzle sealed. A hollow fiber membrane having a molecular weight cut-off of 6000 and an inner diameter of 0.6mm and an outer diameter of 1.00mm was used.

The hollow fiber membrane end portion on the first tubular member side was sealed with a sealing material, and a cross plate having the same composition as the potting material described later (two plates having a height of 63mm×136mm×5mm in thickness were joined so that the cross section in the direction orthogonal to the height direction was cross-shaped) was disposed in the hollow fiber membrane bundle so that the height direction of the cross plate became the length direction of the hollow fiber membrane bundle as the offset restricting member. Further, a centrifugal casting cup having a shape shown in fig. 7 (b) is attached to an end portion of the first tubular member.

At the second tubular member end, a spacer of the shape shown in fig. 3 (a) (a shape obtained by combining 6 prism members of 0.4cm×0.6cm×10 cm) using the same material as the potting material was disposed such that the distance between the end face of the hollow fiber membrane on the second tubular member side and the outer end face of the second adhesive fixing portion was 0.8mm, the distance between the spacer and the end face of the hollow fiber membrane on the second tubular member side was 0mm (the state where the spacer was substantially in contact with the hollow fiber membrane), and the distance between the spacer and the outer end face of the second adhesive fixing portion was 0mm (the state where the outer end face of the spacer was in agreement with the outer end face of the second adhesive fixing portion). Next, a casting jig made of high-density polyethylene having the shape shown in fig. 7 (a) was attached, and after casting of a potting material described later was completed, openings having a partially circular arc shape were formed around (opening area 800 mm) ² Center angle: 80 °, width: 8 mm), the partially circular-arc-shaped opening has a width. Thereafter, a centrifugal casting cup is attached in the same manner as the end of the first tubular member.

Next, the potting material introduction tube is mounted in the cups mounted on the first and second cylindrical members, respectively. The housing is fixed to the centrifugal frame with the nozzle oriented vertically upward, and the potting material is injected into the first and second cylindrical members of the housing by rotating the housing in the horizontal direction. The potting material used was a two-pack curable epoxy resin. The curing reaction of the potting material is performed, and the rotation of the centrifuge is stopped at the time when the fluidization is stopped. The housing was removed from the centrifuge frame and heated to 90 ℃ in an oven to complete curing.

The cup is removed from the first tubular member, and the outer end of the cured potting material is cut off, so that the hollow portion of the hollow fiber membrane is opened. On the second tubular member side, the cup and the casting jig were removed to form an opening having a partially circular arc shape (opening area: 800 mm) ² ) The partial circular arc opening has a width.

Then, caps having the shape shown in fig. 1 with an opening of 66mm in diameter were fixed to both sides of the housing in a liquid-tight manner by tightening nuts via O-rings, thereby obtaining an external pressure type hollow fiber membrane module.

The sum A of the opening areas of the through holes of the external pressure type hollow fiber membrane module was 3200mm ² The sum of the opening areas of the hollow parts of the hollow fiber membrane was 3280mm ² The opening area C of the opening of the cover is 3421mm ² The area S obtained by subtracting the inner occupied area of the net (protective member) from the inner cross-sectional area of the housing (second tubular member) was 7210mm ² . Thus, A/B was 0.98, C/B was 1.04, and A/S was 0.44.

Operation of external pressure hollow fiber Membrane Module

The obtained external pressure type hollow fiber membrane module was attached to an evaluation device shown in fig. 8 a such that the first tubular member side was the upper side in the vertical direction and the second tubular member side was the lower side in the vertical direction (in fig. 8 a, a water tank, a pump, etc. were omitted). The following operations were performed: at 12.4m ³ The flow rate of the water supply was 0.4m ³ The flow rate of/h discharged water from the nozzle was 12m ³ Flow rate of filtered water/h. At this time, the fluid velocity (linear velocity) at each portion calculated from the opening area was 1.07m/s at the through-hole, and was found to be in the hollow fiber membraneThe hollow portion was 1.02m/s, 1.00m/s at the opening of the lid on the water supply side, and 0.97m/s at the opening of the lid on the filtered water side.

The above-described operation conditions were maintained for continuous operation, and leakage was checked once a day for about 5 minutes. Leakage due to breakage of the hollow fiber membranes did not occur after one year.

Example 2 (use case)

The operation was continued in the same manner as in example 1 except for the operation conditions shown in table 1, and the leak test was performed once a day for about 5 minutes.

Since no leakage due to breakage of the hollow fiber membrane occurred even after 30 days from the start of operation, the amount of water to be supplied was increased by 30% from the 31 st day and the operation was continued (amount of water to be supplied 20.6 m) ³ /h, discharge water content 0.6m ³ /h, water permeation quantity 20m ³ On day 91, the occurrence of leakage due to breakage of one hollow fiber membrane was confirmed. After that, the broken hollow fiber membrane was repaired and the operation was continued, and then the operation was terminated until 150 days, without leakage.

Example 3 (simulation)

In the external pressure type hollow fiber membrane module manufactured in example 1, as shown in fig. 9, a calculation model was constructed in which only half of the second adhesive fixing portion (one of the two portions divided into two on the surface parallel to the longitudinal direction of the housing) was taken out, and the deformation amount was estimated when only the predetermined water pressure was applied to the outer end surface of the second adhesive fixing portion.

As for the calculation model, more specifically, it is half of the end portion of the hollow fiber membrane bundle 3 and the second adhesive fixing portion 5b in which the spacer 15 is buried. The shape of the spacer 15 is as described in example 1 above, and is as shown in fig. 3 a. The second adhesive fixing portion 5b is composed of two parts, that is, a portion 5bh in which the hollow fiber membrane bundle is fixed with the potting material and a portion 5bm (including a spacer 15 made of the same material as the potting material and disposed so as to separate the hollow fiber membrane bundle from the outer end surface) which is a single material portion, in a majority of the hollow fiber membrane bundle 3 (the hollow fiber membrane bundle occupies approximately 70% in terms of its outer diameter in a cross section orthogonal to the longitudinal direction of the housing).

The simulation result (displacement distribution) is shown in fig. 11. Fig. 11 (a) is a perspective view; fig. 11 b is a cross-sectional view (a view of a dividing surface when the second adhesive fixing portion is divided into two portions as described above). The second adhesive fixing portion has a concave shape at the center as viewed from the outer end surface side, and the deformation amount gradually increases from the outer periphery toward the center, and the maximum value of the deformation amount is 0.98mm at the center.

Comparative example 1 (use example)

In the evaluation device shown in fig. 8 (b), the hollow fiber membrane module disclosed in example 1 of patent document 1 was manufactured, and the hollow fiber membrane module was mounted so that the pipe 10a was the upper side in the vertical direction and the pipe 11a was the lower side in the vertical direction in the same manner as in example 1 of patent document 1 (in fig. 8 (b), the water tank, the pump, and the like were omitted). In this hollow fiber membrane module, a gap portion having a concentric shape in a cross section orthogonal to the longitudinal direction of the housing between the outer wall of the rectifying tube 28 and the inner wall of the main body 13 is regarded as a portion corresponding to the through hole in the external pressure type hollow fiber membrane module of the embodiment.

The dimensions of each part were calculated by proportional calculation from the values disclosed in patent document 1 and fig. 1 and 3 of patent document 1. Thus, the outer diameter and the inner diameter of the concentric openings of the gap portion were calculated as 154mm and 149.6mm, respectively, and the area corresponding to the sum A of the opening areas of the through holes was calculated as 1049mm ² . Similarly, since the hollow portion of the hollow fiber membrane has a diameter of 0.6mm and the number of the hollow portions is 11600, the sum B of the opening areas of the hollow portions of the hollow fiber membrane is calculated to be 3280mm ² . Further, since the opening diameter of the cover 10 corresponding to the filtered water discharge side cover in the present invention was calculated to be 20mm by the ratio, the opening area C of the filtered water side was calculated to be 314mm ² Since the diameter of the opening 21a of the lower nozzle 21 corresponding to the water supply side cover of the present invention is 58mm, the opening area C of the water supply side is 2642mm ² . Further, the outer diameter of the drift suppression section 29 is calculated from the inner diameter 162mm of the header section 15 and the ratio calculation145.2mm the area S obtained by subtracting the inner occupied area of the protection member (the net-like drift suppression section 29) from the inner cross-sectional area of the housing (the header 15) was 4053mm ² 。

The linear velocity at each location and A/B, C/B, A/S at this time are shown in Table 1.

The membrane module was continuously operated under the same operating conditions as in example 2, and was subjected to leak test once a day for about 5 minutes.

Since no leakage due to breakage of the hollow fiber membrane occurred even after 30 days from the start of operation, the amount of water to be supplied was increased by 30% from the 31 st day and the operation was continued (amount of water to be supplied 20.6 m) ³ /h, discharge water content 0.6m ³ /h, water permeation quantity 20m ³ On day 49, the occurrence of leakage due to breakage of one hollow fiber membrane was confirmed. After that, the broken hollow fiber membranes were repaired and further operation was continued, and then, on the 77 th day, the occurrence of leakage due to the breakage of one hollow fiber membrane was confirmed, and the operation was terminated.

Comparative example 2 (simulation)

As shown in fig. 10, the same conditions as those in example 3 were applied except that the calculation model was changed to a state in which no spacer was provided and the outer end face of the second adhesive fixing portion was not separated from the closed end face of the hollow fiber membrane bundle 3 (the end face on the closed end side (closed end face) of the hollow fiber membrane bundle 3 was only the membrane bundle containing portion 5bh that was coincident with the outer end face of the second adhesive fixing portion).

The simulation result (displacement distribution) is shown in fig. 12. Fig. 12 (a) is a perspective view; fig. 12 b is a cross-sectional view (a view of a dividing surface when the second adhesive fixing portion is divided into two as described above). The point where the deformation amount gradually increases from the outer peripheral center portion and the position of the maximum value of the deformation amount are the same as in example 3, but the maximum value of the deformation amount is 2.15mm, showing a maximum deformation amount of about 2 times that of example 3.

[ Table 1 ]

[ Table 2 ]

[ Utility ] A method for manufacturing a semiconductor device

The external pressure type hollow fiber membrane module of the present invention has excellent durability and excellent uniformity of pressure distribution and velocity distribution of fluid passing through the inside, and has little pressure loss, and therefore, is particularly suitable for use as a final filtration membrane module of ultrapure water used in cleaning in the production of silicon wafers, LSI, liquid crystals, and the like.

[ PREPARATION ] A method for producing a polypeptide

1. External pressure type hollow fiber membrane assembly

2. Hollow fiber membrane

Closed end face of 2e hollow fiber membrane

3. Hollow fiber membrane bundle

4. Shell body

5a first adhesive fixing portion

5b second adhesive fixing portion

The 5bh membrane bundle contains portions

5bm single material portion

5e outer end face of the second adhesive fixing portion

6. 23, 33 through holes

7. Protective member

8. Cover for a container

9a first tubular member

9b second tubular member

10. Third tubular member

11a first rectifying cylinder

11b second rectifying cylinder

12. Nozzle

13. Nut

14 O-shaped ring

15. Spacing piece

21. 31, 41, 51 output (outlet)

22. 32, 42, 52 input (intlet)

53 baffle

Claims

1. An external pressure type hollow fiber membrane module, comprising: a bundle of hollow fiber membranes, each bundle being formed by bundling a plurality of hollow fiber membranes each having one end portion thereof closed and the other end portion thereof open;

2. The external pressure type hollow fiber membrane module according to claim 1, wherein a cross-sectional shape of the spacer in a direction orthogonal to a longitudinal direction of the housing is a shape selected from the group consisting of a ring (circle), a lattice, a cross, a radial, a honeycomb, and a combination thereof.

3. The external pressure type hollow fiber membrane module according to claim 1 or 2, wherein the spacer is composed of the same raw material as the second adhesive fixing portion.