CN111587145B

CN111587145B - Filtering module

Info

Publication number: CN111587145B
Application number: CN201880086284.7A
Authority: CN
Inventors: 池田启一; 森田徹
Original assignee: Sumitomo Electric Industries Ltd
Current assignee: Sumitomo Electric Industries Ltd
Priority date: 2018-01-24
Filing date: 2018-11-21
Publication date: 2022-06-14
Anticipated expiration: 2038-11-21
Also published as: WO2019146229A1; CN111587145A; JP7003685B2; JP2019126769A

Abstract

A filter module according to an aspect of the present disclosure is provided with: a plurality of hollow fiber membranes drawn to be aligned in one direction; a cylindrical housing that stores the hollow fiber membranes and has a concentrate nozzle for discharging a concentrate on one side surface thereof; and an introduction preventing member which is inserted into the concentrate nozzle and prevents the hollow fiber membranes from entering the concentrate nozzle.

Description

Filtering module

Cross Reference to Related Applications

This application is based on and claimed for priority from japanese patent application No. 2018-009547, filed on the sun at 24.1.2018, the entire content of which is incorporated herein by reference.

Technical Field

The present disclosure relates to a filtration module.

Background

In order to filter various process liquids, a filter module known as a cross-flow filtration module (cross-flow filtration module) is used in which a plurality of hollow fiber membranes arranged in one direction are accommodated in a tubular housing, a process liquid is supplied into the housing from a process liquid nozzle provided at one end of the housing, a filtrate that has passed through the hollow fiber membranes is discharged from a filtrate nozzle provided at the other end of the housing, and a concentrate concentrated from the process liquid is discharged from a concentrate nozzle provided at a side surface near the other end of the housing.

In such a filtration module, in order to prevent the introduction of hollow fiber membranes into the (draw intro) concentrate nozzle, a distribution cylinder having a plurality of distribution holes is arranged on the inside of the concentrate nozzle so as to surround the bundle of hollow fiber membranes (international publication WO 2008/035593).

Documents of the related art

[ patent document ]

Patent document 1: international publication WO2008/035593

Disclosure of Invention

According to an aspect of the present disclosure, a filtration module includes a plurality of hollow fiber membranes, a tubular housing, and an introduction prevention member. The plurality of hollow fiber membranes are arranged in one direction. A tubular housing houses the plurality of hollow fiber membranes and includes a concentrate nozzle. The concentrate nozzle is disposed on a side surface of the tubular housing and discharges the concentrate. The introduction preventing member is inserted into the concentrate nozzle and prevents the hollow fiber membranes from entering into the concentrate nozzle.

Drawings

Fig. 1 is a perspective cross-sectional view of a filtration module according to an embodiment of the present disclosure; and is

Fig. 2 is an enlarged perspective view of an introduction preventing member of the filter module of fig. 1.

Detailed Description

[ problem to be solved by the present disclosure ]

In the filter module including the dispensing cartridge as disclosed in patent document 1, if fibrous contaminants are contained in the treatment liquid, the contaminants may be tangled with the dispensing cartridge, and as a result, the dispensing holes of the dispensing cartridge may be clogged with the contaminants. In this case, it is difficult to remove contaminants without disassembling the filter module.

In view of the above, it is an object of the present disclosure to provide a filter module capable of easily removing contaminants when a flow path is clogged with the contaminants.

[ Effect of the present disclosure ]

According to an aspect of the present disclosure, the filter module can easily remove contaminants when the flow path is clogged with the contaminants.

[ description of embodiments of the present disclosure ]

A filtration module includes a plurality of hollow fiber membranes, a tubular housing, and an introduction-preventing member. The plurality of hollow fiber membranes are arranged in one direction, and a tubular housing accommodates the plurality of hollow fiber membranes and includes a concentrate nozzle. The concentrate nozzle is disposed on a side surface of the tubular housing and discharges the concentrate. The introduction prevention member is inserted into the concentrate nozzle and prevents the hollow fiber membranes from entering into the concentrate nozzle.

In the filtration module, the introduction prevention member is configured to be inserted into the concentrate nozzle and prevent the hollow fiber membranes from entering into the concentrate nozzle. Therefore, in the case where the introduction prevention member is clogged with the contaminants contained in the treatment liquid, the introduction prevention member can be pulled out from the concentrate nozzle to be cleaned. Therefore, the contaminants can be easily removed, and thus the filtering ability can be restored.

The introduction preventing member described above may include: an inner cylindrical portion disposed on an inner side of the concentrate nozzle; and a dome-shaped sealing portion that seals a tip end of the inner cylindrical portion and has a plurality of openings through which the concentrated liquid passes. The sealing portion may protrude into the housing, and the plurality of openings may be elongated openings extending toward a tip end of the sealing portion. With the above configuration, the introduction prevention member includes the inner cylindrical portion disposed on the inner side of the concentrate nozzle. Therefore, the sealing portion can be arranged at the inner side of the housing, and the hollow fiber membranes can be prevented from being introduced into the concentrate nozzle by the flow of the concentrate. Further, since the seal portion that seals the tip end of the inner cylindrical portion is formed in a dome shape, the total area of the plurality of openings through which the concentrate passes can be increased, and therefore a sufficient flow path area can be ensured. Further, the plurality of openings are elongated openings extending toward the tip end of the seal portion. Therefore, even if the hollow fiber membranes are brought into contact with the openings, since the direction in which the openings extend is different from the direction in which the hollow fiber membranes extend, the hollow fiber membranes are not easily introduced into the openings and do not easily clog the openings.

The elongated plurality of openings may be arranged in a plurality of rows in a direction toward a top end of the seal portion, and the rows may each include a plurality of openings. When the above-described elongated openings are arranged in a plurality of rows in a direction toward the tip end of the seal portion and the rows each include a plurality of openings, the total area of the plurality of openings can be increased.

An area where no opening exists may be included at a tip end in the protruding direction of the seal portion. The tip in the protruding direction of the seal portion easily contacts the hollow fiber membrane. Therefore, by forming a region where there is no opening at the tip end of the seal portion, introduction of the hollow fiber membrane can be reliably prevented while the strength of the seal portion can also be maintained.

The introduction prevention member may comprise a fitting portion fitted on the outer end of the concentrate nozzle. Since the introduction-preventing member comprises a fitting portion, and the fitting portion is fitted on the outer end of the concentrate nozzle, the seal portion can be easily and reliably arranged at a proper position. Therefore, the introduction of the hollow fiber membrane can be reliably prevented.

[ details of embodiments of the present disclosure ]

A filter module according to an embodiment of the present disclosure will be described below with reference to the accompanying drawings.

Fig. 1 illustrates a filtration module according to an embodiment of the present disclosure. The filtration module comprises a membrane element 2 and a tubular housing 3. The membrane element 2 includes a plurality of hollow fiber membranes 1 arranged in one direction, and the tubular housing 3 accommodates the membrane element 2 including the plurality of hollow fiber membranes 1.

The membrane element 2 includes a first holding member 4 and a second holding member 5, the first holding member 4 holding one end portion of the plurality of hollow fiber membranes 1, the second holding member 5 holding the other end portion of the plurality of hollow fiber membranes 1. Furthermore, the membrane element 2 comprises a coupling member 6, which coupling member 6 connects the first holding member 4 and the second holding member 5 and determines the relative position between the first holding member and the second holding member.

The housing 3 includes a treatment liquid nozzle 7 on one end surface, a filtration liquid nozzle 8 on the other end surface, and a concentrate liquid nozzle 9 on a side surface near the other end. The treatment liquid nozzle 7 supplies the treatment liquid, the filtrate nozzle 8 discharges the liquid that has been filtered through the plurality of hollow fiber membranes 1, and the concentrate nozzle 9 discharges the concentrate obtained by separating the filtrate from the treatment liquid.

The filtration module further comprises an introduction preventing member 10. The introduction prevention member 10 is inserted into the concentrate nozzle 9 from the outside and prevents the hollow fiber membranes 1 from entering into the concentrate nozzle 9.

In the filtration module, the introduction prevention member 10 is inserted into the concentrate nozzle 9 from the outside, and the hollow fiber membranes 1 are prevented from being introduced into the concentrate nozzle 9 together with the concentrate. Therefore, if the flow path of the introduction prevention member 10 is clogged by the contaminants contained in the process liquid (the concentrate), the introduction prevention member 10 can be pulled out from the concentrate nozzle 9 and the contaminants can be removed. Therefore, even if the flow path of the concentrate is blocked, the filter module can easily recover the filtering capability without being completely disassembled.

Hereinafter, constituent elements of the filter module will be described.

< Membrane element >

The membrane element 2 allows the plurality of hollow fiber membranes 1 to be integrally held by the first holding member 4, the second holding member 5, and the coupling member 6 in a state where the plurality of hollow fiber membranes 1 are arranged in the housing in one direction.

(hollow fiber Membrane)

The hollow fiber membrane 1 is a tubular porous membrane that prevents permeation of impurities contained in the treatment liquid and having a certain particle diameter or more, while allowing a solvent in the treatment liquid to permeate through the hollow fiber membrane. For example, the main component of the hollow fiber membrane 1 may be a thermoplastic resin. As used herein, the term "major component" refers to the component having the greatest content.

Examples of the thermoplastic resin include polyethylene, polypropylene, polyvinylidene fluoride, ethylene-vinyl alcohol copolymer, polyamide, polyimide, polyetherimide, polystyrene, polysulfone, polyvinyl alcohol, polyphenylene ether, polyphenylene sulfide, acetyl cellulose, polyacrylonitrile, and Polytetrafluoroethylene (PTFE). Among them, preferred is PTFE, which is porous and has excellent mechanical strength, chemical resistance, heat resistance, weather resistance and incombustibility, and more preferred is uniaxially (uniaxially) or biaxially (biaxially) stretched PTFE. Note that the material of the hollow fiber membrane 1 may suitably include other polymers and additives, such as a lubricant.

The lower limit of the ratio of the average pitch (pitch) to the average outer diameter of the hollow fiber membrane 1 is preferably 1. The upper limit of the ratio of the average pitch to the average outer diameter of the hollow fiber membrane 1 is preferably 3/2, more preferably 7/5. If the ratio of the average pitch to the average outer diameter of the hollow fiber membranes 1 is less than the above lower limit, the hollow fiber membranes 1 will be arranged in a state of being pressed in the radial direction, and thus it is difficult to manufacture the membrane element 2. If the ratio of the average pitch to the average outer diameter of the hollow fiber membranes 1 exceeds the above upper limit, the density of the hollow fiber membranes 1 decreases, resulting in insufficient filtration efficiency.

The lower limit of the average outer diameter of the hollow fiber membrane 1 is preferably 1mm, more preferably 1.5mm, and even more preferably 2 mm. The upper limit of the average outer diameter of the hollow fiber membrane 1 is preferably 6mm, more preferably 5mm, and even more preferably 4 mm. If the average outer diameter of the hollow fiber membranes 1 is less than the above lower limit, the mechanical strength of the hollow fiber membranes 1 will be insufficient. If the average outer diameter of the hollow fiber membranes 1 exceeds the above upper limit, the flexibility of the hollow fiber membranes 1 will be insufficient, resulting in that the hollow fiber membranes 1 cannot be sufficiently vibrated and oscillated when the bubbles contact the hollow fiber membranes 1. As a result, the gap between the hollow fiber membranes 1 will not increase, and therefore the air bubbles will not be guided to the center of the bundle of hollow fiber membranes 1. In addition, the ratio of the surface area to the sectional area of the hollow fiber membrane 1 will be reduced, thus resulting in insufficient filtration efficiency.

The lower limit of the average inner diameter of the hollow fiber membrane 1 is preferably 0.3mm, more preferably 0.5mm, and even more preferably 0.9 mm. The upper limit of the average inner diameter of the hollow fiber membrane 1 is preferably 4mm, and more preferably 3 mm. If the average inner diameter of the hollow fiber membranes 1 is less than the above lower limit, there will be an increase in pressure loss when the treatment liquid filtered through the hollow fiber membranes 1 is discharged. If the average inner diameter of hollow fiber membranes 1 exceeds the above upper limit, the thickness of hollow fiber membranes 1 will decrease, resulting in insufficient mechanical strength and insufficient effect of preventing permeation of impurities.

The lower limit of the ratio of the average inner diameter to the average outer diameter of the hollow fiber membrane 1 is preferably 3/10, and more preferably 2/5. The upper limit of the ratio of the average inner diameter to the average outer diameter of the hollow fiber membrane 1 is preferably 4/5, and more preferably 3/5. If the ratio of the average inner diameter to the average outer diameter of the hollow fiber membranes 1 is less than the above lower limit, the thickness of the hollow fiber membranes 1 will be excessively large. As a result, the water permeability of the hollow fiber membrane 1 will be reduced. If the ratio of the average inner diameter to the average outer diameter of the hollow fiber membranes 1 exceeds the above upper limit, the thickness of the hollow fiber membranes 1 will decrease, resulting in insufficient mechanical strength and insufficient effect of preventing the permeation of impurities.

(first holding member)

The first holding member 4 airtightly holds the end portions on one side of the plurality of hollow fiber membranes 1 while allowing the end portions on the one side of the plurality of hollow fiber membranes 1 to be opened. In addition, the first holding member 4 is airtightly engaged with the inner wall near one side of the housing 3, thereby dividing a space in the housing 3. A smaller space leading to the inner cavities of the plurality of hollow fiber membranes 1 is formed at the one side of the housing 3.

The first holding member 4 may be configured to include a support body and a filler. The support body has a shape engaged with the housing 3, and has a plurality of through holes into which end portions on the one side of the plurality of hollow fiber membranes 1 are inserted. Gaps between the support body and the plurality of hollow fiber membranes 1 are filled with a filler.

Examples of the material of the support body include PTFE, polyvinyl chloride, polyethylene, and Acrylonitrile Butadiene Styrene (ABS) resin.

Examples of the filler used include a material having high adhesion to the hollow fiber membrane 1 and capable of curing in the support body. In particular, when PTFE is used as the main component of the hollow fiber membrane 1, the main component of the filler is preferably epoxy resin or polyurethane, which has high adhesion to PTFE and can reliably prevent the shedding of the hollow fiber membrane 1. By filling the support body with the filler, the space between the hollow fiber membranes 1 and the support body can be hermetically sealed, and therefore, the filtered treatment liquid can be prevented from being mixed with the unfiltered treatment liquid from the outside of the membranes.

(second holding Member)

The second holding member 5 holds the end portions on the other side of the plurality of hollow fiber membranes 1 so that the plurality of hollow fiber membranes 1 are arranged in one direction without entanglement. The second holding member 5 holds the end portions on the other side of the plurality of hollow fiber membranes 1 so as not to allow the internal space of the hollow fiber membranes 1 to be opened. Further, the second holding member 5 is configured to form a space between the second holding member 5 and the inner wall of the housing 3, or to have an opening that allows the processing liquid to pass through, so that the inner space of the housing 3 is not divided by the second holding member 5.

The second holding member 5 may be configured to include a support body and a filler. The support body has a plurality of non-through holes into which the end portions on the other side of the plurality of hollow fiber membranes 1 are inserted, and the gaps between the support body and the plurality of hollow fiber membranes 1 are filled with a filler.

The material of the support body and the material of the packing of the second holding member 5 may be the same as the material of the support body and the packing of the first holding member 4.

(connecting member)

The coupling member 6 couples the first holding member 4 and the second holding member 5, which are arranged opposite to each other in the vertical direction, and holds the second holding member 5 at a predetermined position in the housing 3.

Further, the coupling member 6 allows the first holding member 4, the second holding member 5, and the plurality of hollow fiber membranes 1 arranged therebetween to be integrally coupled, thereby facilitating the disassembly and assembly of the filtration module.

The coupling member 6 may be a support rod made of resin, metal, or the like.

< housing >

The housing 3 may be configured to include a tubular body 11, a first bushing 12, a first cap 13, a second bushing 14, and a second cap 15. The first bushing 12 is attached to one end of the body 11 and is provided with an engagement structure with which the concentrate nozzle 9 and the first holding member 4 are engaged. The first cap 13 seals the end of the first liner 12 on the opposite side of the body 11, and is provided with the filtrate nozzle 8. A second bushing 14 is attached to the other end of the body 11. The second cap 15 seals an end of the second liner 14 on the opposite side of the body 11, and is provided with the treatment liquid nozzle 7.

With the above configuration, a commercially available pipe or the like can be used as the main body 11. Therefore, the length of the hollow fiber membrane 1 to be used, that is, the filtration area can be selected relatively freely. In particular, by separately producing the body 11 and the first bush 12, the engaging structure with which the nozzle 9 and the first holding member 4 are engaged can be produced accurately and inexpensively.

Further, first and

second caps

13 and 15 are removably attached to first and

second bushings

12 and 14, respectively. Thus, the filter module can be disassembled when cleaned. To remove and attach the first and

second caps

13 and 15, any structure used as a pipe joint, such as a screw, a flange, or a ferrule, may be employed.

For example, the material of each constituent element of the case 3 may be a metal such as iron, stainless steel, or aluminum, or may be a resin composition including PTFE, polyvinyl chloride, polyethylene, or ABS resin as a main component. The constituent elements may be of different materials.

The treatment liquid nozzle 7, the filtrate nozzle 8 and the concentrate nozzle 9 include joint structures that connect pipes to the outer ends of the nozzles. As the engaging structure, a flange or a ferrule may be employed instead of the external screw as shown in the drawings.

< introduction prevention means >

Fig. 2 shows a detail of the introduction-preventing member 10. The introduction prevention member 10 includes: an inner cylindrical portion 16 arranged on the inside of the concentrate nozzle 9; a seal portion 17 that seals the tip end of the inner cylindrical portion 16; a fitting portion 18 which is fitted on the outer end of the concentrate nozzle 9.

The introduction prevention member 10 is connected to the joint structure of the concentrate nozzle 9. The attachment member 19 presses the fitting 18 against the outer end of the concentrate nozzle 9, so that the introduction preventing member 10 inserted into the concentrate nozzle 9 is fixed to the concentrate nozzle 9.

(inner cylindrical part)

In order to allow the inner cylindrical portion 16 to be inserted into the concentrate nozzle 9 and to remove the inner cylindrical portion 16 from the concentrate nozzle 9, the inner cylindrical portion 16 is preferably formed in a tubular shape with an outer diameter that minimizes a clearance with an inner wall surface of the concentrate nozzle 9. In addition, it is also possible to make the diameter of the inner cylindrical portion 16 slightly smaller toward the seal portion 17 so that the inner cylindrical portion 16 is formed integrally with the seal portion 17 and the fitting portion 18 by injection molding.

The inner cylindrical portion 16 may be connected to the tip of a tube that discharges the concentrated liquid, or may be fixed inside the concentrated liquid nozzle 9 by an attachment member 19 connected to the tip of the tube that discharges the concentrated liquid.

The average thickness of the inner cylindrical portion 16 may be any thickness as long as sufficient strength can be maintained, and can be greater than or equal to 2mm and less than or equal to 10mm, depending on the material, for example.

(sealing part)

The sealing portion 17 is formed in a dome shape and has a plurality of openings 20 through which the concentrate can pass. Furthermore, the seal 17 projects into the housing 3. The term "dome shape" refers to any gently protruding circular shape, such as a sphere, an ellipsoid, or a cone with a chamfered top.

By forming the seal 17 in a dome shape, any hollow fiber membrane 1 that may come into contact with the seal 17 is not easily damaged. In addition, the total area of the openings 20 can be increased, and thus a sufficient flow path area can be ensured.

It is preferable that a region where the opening 20 does not exist is included at the tip end in the protruding direction of the seal portion 17. The tip in the protruding direction of the seal part 17 can easily contact the hollow fiber membrane 1. Therefore, by forming a region where there is no opening 20 at the tip end in the protruding direction of the seal part 17, damage of the hollow fiber membrane 1 can be reliably prevented. Further, the tip in the protruding direction of the seal portion 17 has a surface substantially parallel to the extending direction of the hollow fiber membranes 1. Therefore, the hollow fiber membranes 1 are easily attached to the seal part 17 by the flow of the concentrated solution. If the area of the opening 20 is reduced due to the attachment of the hollow fiber membrane to the opening 20, contaminants are easily attached to the opening 20. Therefore, by not forming the opening 20 in this region, adhesion of contaminants can be reduced.

The thickness of the seal portion 17 may be any thickness as long as sufficient strength can be maintained. To increase the flow path area, the thickness of the sealing portion 17 may be slightly smaller than the thickness of the inner cylindrical portion 16. The average thickness of the sealing portion 17 may be greater than or equal to 2mm and less than or equal to 10mm depending on the material.

Preferably, each opening 20 of the seal 17 is an elongated opening extending towards the top end of the seal 17. When each opening 20 is an elongated opening extending toward the tip of the seal 17, even if the hollow fiber membranes 1 come into contact with the opening 20, the opening 20 is not easily clogged with the hollow fiber membranes 1. This is because the direction in which the openings 20 extend is different from the direction in which the hollow fiber membranes 1 extend.

Furthermore, preferably several openings 20 are arranged in the sealing 17 in a direction towards the top end of the sealing 17. If a long opening extending from the vicinity of the inner cylindrical portion 16 to the vicinity of the tip end of the seal portion 17 is formed, the strength of the seal portion 17 becomes insufficient. Therefore, by arranging several openings 20 in a direction toward the tip end of the seal portion 17, the strength of the seal portion 17 can be easily ensured. In addition, by forming and arranging several openings 20 in a direction toward the tip end of the seal portion 17, the opening ratio in the circumferential direction of the seal portion 17 can be increased, thus increasing the total area of the plurality of openings 20.

Preferably, the peripheral edge of each opening 20 at least on the outer surface side of the seal 17 is chamfered so that any hollow fiber membranes 1 that may come into contact with the seal 17 are not damaged.

The lower limit of the short axis (longest width) of the opening 20 is preferably 3mm, and more preferably 5 mm. The upper limit of the minor axis of the opening 20 is preferably 12mm, and more preferably 10 mm. If the minor axis of the opening 20 is less than the above lower limit, the opening 20 will be easily clogged with contaminants. If the short axis of the opening 20 exceeds the above upper limit, the hollow fiber membrane will be easily introduced into the opening, thereby clogging the opening.

The lower limit of the major axis (longest length) of the opening 20 is preferably 10mm, and more preferably 15 mm. The upper limit of the long axis of the opening 20 is preferably 30mm, and more preferably 25 mm. If the long axis of the opening 20 is smaller than the above lower limit, it will be difficult to increase the area of the opening 20 in the seal portion 17, and thus it will be difficult to sufficiently increase the flow path area. If the long axis of the opening 20 exceeds the upper limit, it is difficult to maintain the strength of the seal 17.

The lower limit of the total area of the plurality of openings 20 is preferably 110% of the sectional area of the inner cylindrical portion 16, and more preferably 130%. The upper limit of the total area of the plurality of openings 20 is preferably 180% of the sectional area of the inner cylindrical portion 16, and more preferably 160%. If the total area of the plurality of openings 20 is less than the above-mentioned lower limit, the openings 20 will be easily clogged with contaminants. If the total area of the plurality of openings 20 exceeds the above upper limit, the strength of the seal 17 will become insufficient, or the size of the seal 17 will excessively increase, thereby interfering with the hollow fiber membranes 1.

(matching part)

The mating portion 18 projects outwardly from the inner cylindrical portion 16 and abuts the outer end of the concentrate nozzle 9. In this way, the position of the introduction-preventing member 10 with respect to the housing 3 is determined. Therefore, the introduction blocking member 10 can be fixed at an appropriate position of the housing 3, and the hollow fiber membranes 1 can be reliably prevented from being introduced into the concentrate nozzle 9.

The fitting portion 18 may be provided on a part of the outer periphery of the inner cylindrical portion 16. However, in order to hermetically seal the gap between the fitting portion 18 and the concentrate nozzle 9, it is preferable to provide the annular fitting portion 18 on the entire outer periphery of the inner cylindrical portion 16. The fitting portion 18 may have a structure that holds a sealing member, such as an O-ring 21, which seals a gap between the fitting portion 18 and the outer end of the concentrate nozzle 9.

< attachment Member >

The attachment member 19 has a joint structure similar to that of the treatment liquid nozzle 7, and holds the fitting portion 18 such that the fitting portion 18 abuts against the outer end of the concentrate nozzle 9. The attachment member 19 may be a flange or ferrule rather than a nipple nut (union nut) as shown in the figures.

Depending on the joint structure of the treatment liquid nozzle 7, a part or all of the attachment member 19 may be integrally formed with the introduction-preventing member 10.

[ other examples ]

It should be understood that the embodiments disclosed herein are exemplary in all respects, and are not intended to be limiting in any way. The scope of the present invention is defined not by the above-described embodiments but by the scope of the claims, and is intended to include all modifications within the meaning and scope equivalent to the scope of the claims.

In the filtration module, the membrane element including the plurality of hollow fiber membranes may have any configuration. Further, it is not necessary to form a removable membrane element, and the plurality of hollow fiber membranes may be permanently arranged in the housing.

The introduction preventing member of the filtration module need not include the inner cylindrical portion and the sealing portion as long as the introduction preventing member allows the concentrate to flow into the concentrate nozzle while preventing the hollow fiber membranes from entering into the concentrate nozzle. Further, the sealing portion of the introduction prevention member may have any configuration.

List of reference numerals

1 hollow fiber membrane

2 Membrane element

3 case

4 first holding member

5 second holding Member

6 connecting component

7 treating liquid nozzle

8 filtering liquid nozzle

9 concentrated solution nozzle

10 introduction prevention member

11 body

12 first bush

13 first cap

14 second bushing

15 second cap

16 inner cylindrical part

17 sealing part

18 mating part

19 attachment member

20 opening

21O-ring

Claims

1. A filtration device comprising:

a plurality of hollow fiber membranes arranged in one direction;

a tubular housing that accommodates the plurality of hollow fiber membranes and includes a concentrate nozzle that is arranged on a side surface of the tubular housing and discharges a concentrate; and

an introduction preventing member that is inserted into the concentrate nozzle and prevents the hollow fiber membranes from entering into the concentrate nozzle,

wherein the introduction preventing member includes:

an inner cylindrical portion disposed inside the concentrate nozzle; and

a dome-shaped seal portion that seals a tip end of the inner cylindrical portion and has a plurality of openings through which the concentrated liquid passes, and

wherein the seal portion protrudes into the housing, and the plurality of openings are elongated openings extending toward a top end of the seal portion.

2. The filtration device of claim 1, wherein the plurality of elongated openings are arranged in a plurality of rows in a direction toward the top end of the seal portion, the rows each including a plurality of openings.

3. The filter device according to claim 1 or 2, wherein the seal comprises an area where the opening is absent, the area being located at the top end of the seal.

4. A filter device according to claim 1 or 2, wherein the introduction preventing member comprises a fitting part which is fitted on an outer end of the concentrate nozzle.

5. A filter device according to claim 3, wherein the introduction preventing member comprises a fitting portion fitted on an outer end of the concentrate nozzle.