JPH0621731U - Hollow fiber membrane module - Google Patents

Abstract

(57) [Abstract] [Purpose] To improve the pressure resistance of the hollow fiber membrane module by increasing the adhesive strength between the air vent member and the sealing material. [Structure] A large number of hydrophilic hollow fiber membranes 3 and a hydrophobic air vent member 4 are bundled and inserted into a module case 2,
A hollow fiber membrane in which a gap between the hollow fiber membrane 3, the air vent member 4 and the module case 2 is filled with a sealing material 6 in the opening 5 of the module case 2 to bond and fix the hollow fiber membrane 3 and the air vent member 4. In the module, the adhesive surface 7 of the air vent member 4 with which the sealing material 6 contacts is subjected to surface treatment such as corona discharge treatment for enhancing the wettability of the sealing material 6.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a hollow fiber membrane module used in, for example, a water purifier, and more particularly to a technique for improving pressure resistance in a sealing portion.

[0002]

[Prior art]

 A conventional hollow fiber membrane module of this type has a structure as shown in FIG. 4, for example. That is, a bundle of a large number of hydrophilic hollow fiber membranes 100 is inserted into the module case 101, and the opening 103 of the module case 101 is sealed and fixed by the sealing material 102. Then, the undiluted solution flown into the module case 101 is filtered through the membrane wall of each hollow fiber membrane 100, and the filtered solution flows out to the outside through the passage inside the hollow fiber membrane 100.

If air remains inside the module case 101, the filtering area is reduced by the amount of this air, and the filtering efficiency is deteriorated. Therefore, in order to remove the air staying inside the module case 101, the air is removed. The member 104 is inserted. The surface of the air bleeding member 104 is hydrophobic so that air can surely escape.

[0004]

[Problems to be solved by the device]

 However, in the above-described conventional hollow fiber membrane module, the surface of the air vent member 104 is hydrophobic, so that the sealing material 102 is repelled by the surface of the air vent member 104 when the liquid sealing material 102 is filled. There is a problem that the adhesion strength between the air vent member 104 and the sealing material 102 becomes low. Therefore, when the pressure inside the module case 101 rises due to the progress of clogging, the sealing material 102 may peel off and the hollow fiber membrane module may be damaged, resulting in poor pressure resistance.

The present invention has been made in order to solve the above-mentioned problems of the prior art. The purpose of the present invention is to enhance the adhesive strength between the air vent member and the encapsulant to increase the hollow fiber membrane module. Is to improve the pressure resistance of the.

[0006]

[Means for Solving the Problems]

 In order to achieve the above object, in the present invention, a large number of hydrophilic hollow fiber membranes and a hydrophobic air vent member are bundled and inserted into a module case, and at the opening of the module case. In the hollow fiber membrane module in which the sealing material is filled in the gap between the hollow fiber membrane, the air vent member and the module case to bond and fix the hollow fiber membrane and the air vent member, the adhesion of the air vent member with which the sealing material contacts The surface is subjected to a surface treatment for improving the wettability of the sealing material.

The surface treatment is preferably corona discharge treatment.

[0008]

[Action]

 According to the present invention, the surface of the air-bleeding member that is bonded to the sealing material is subjected to a surface treatment to improve the wettability of the sealing material, so that the sealing material can be widely spread over the bonding surface of the air-bleeding member. Adhesive strength increases. In addition, since the surface treatment is applied only to the adhesive surface, the exposed portion inside the module case retains its hydrophobicity and does not impair the air venting property.

In particular, when the surface of the air vent member is subjected to corona discharge treatment, the surface becomes extremely fine irregularities and wettability is improved. In addition, corona discharge treatment allows the device to be installed online and uses a commercial power source as the power source, so it is as easy to operate as a general machine.

[0010]

【Example】

 The present invention will be described below based on the illustrated embodiment. FIG. 1 shows a hollow fiber membrane module according to an embodiment of the present invention. That is, reference numeral 1 denotes the entire hollow fiber membrane module, and generally, a module case 2, a bundle of a large number of hydrophilic hollow fiber membranes 3 to be inserted into the module case 2, and a hydrophobic air vent member 4 are provided. And a sealing material 6 filled in the gap between the hollow fiber membrane 3, the air vent member 4 and the module case 2 in the case opening 5 of the module case 2.

The hollow fiber membrane module of this embodiment is a full-volume filtration type module in which the hollow fiber membranes 3 are bundled in a U-shaped bent state, and both ends are one of the module cases 2. It is aligned with the opening 5. As shown in FIG. 1 (c), each hollow fiber membrane 3 is formed with a passage 31 penetrating the entire length thereof, and the liquid is filtered through a porous membrane wall 32.

As the air vent member 4, in this embodiment, two hydrophobic flexible films are laminated and heat-welded while leaving a plurality of air passage portions 41 forming an air passage. The hollow fiber membranes 3 are wound around the hollow fiber membranes 3 in a bundle. The air bleeding member 4 has a rectangular shape in plan view, and the air passage portions 41 extend in parallel with the short pieces and are arranged at predetermined intervals in the long piece direction. When the hollow fiber membrane 3 is inserted into the module case 2, each air passage portion 41 of the air vent member 4 comes close to the inner wall surface of the module case 2.

Since the air vent member 4 is hydrophobic and the surface of the heat-welded portion 42 is smooth, the liquid sealing material 6 is repelled. Therefore, the surface of the air vent member 4 is subjected to corona discharge treatment in order to improve the wettability with the sealing material 6. However, if corona discharge treatment is applied to the entire surface of the air bleeding member 4, the wettability of the portion where air should escape becomes better and the air bleeding ability deteriorates. Apply processing. The adhesive surface 7 that contacts the sealing material 6 is present not only on the inner surface side around which the hollow fiber membrane 3 is wound, but also on the outer peripheral surface side facing the inner wall surface of the module case 2. Therefore, corona discharge treatment is performed on both front and back surfaces of the air vent member 4. When corona discharge treatment is performed, the surface becomes very fine irregularities, and the wettability can be improved.

As a method of this surface modification, various surface treatment techniques such as treatment with an additive, treatment with a coupling agent, and ultraviolet irradiation treatment can be applied as long as they can enhance the wettability of the surface. . However, the corona discharge treatment is advantageous because it can be installed online, the commercial power source can be used as the power source, etc.

Here, as shown in FIG. 3, the interfacial tension between the sealing material 6 (liquid) and the film 43 (solid) forming the air vent member 4 is γSL, the sealing material 6 and air (gas), the film. Assuming that the interfacial tensions of 43 and air are γLV and γSV, respectively, and the contact angle of the sealing material 6 on the film 43 is θ, the force balance is γSV = γSL + γLV ・ COSθ. It is expressed as COS θ = γSV-γSL.

Easily wettable (adhesive) means that the contact angle is small, and in the above equation, when θ = 0, γLV = γSV−γSL = γC (seaside interface tension).

That is, the larger the γC, the more easily the surface of the solid gets wet. For example, JIS K6 768 "Method for wetting test of polyethylene and polypropylene film" provides a simple method for obtaining this γC and is evaluated as "wetting index".

In this example, the corona discharge treatment increased the wetting index of the layered air vent member 4 from about 34 [dyne / cm] to 70 [dyne / cm] or more.

The peel strength was about 0.7 kgf / 25 mm before the treatment, but after the treatment, not the peeling of the sealing material 6 but the material destruction occurred (reference 2.2 kgf / 25 mm).

FIG. 2 simply shows a manufacturing process of the hollow fiber membrane module.

That is, a sheet-shaped air vent member 4 is wrapped around a bundle of a large number of U-shaped bent hollow fiber membranes 3 and is inserted into the module case 2 in this state (FIG. 2 (a), ( b) Reference). As shown in FIG. 1 (d), the sheet-shaped air bleeding member 4 has both ends of the air passage portion 41 closed in a state before the sealing step, and an area of the adhesive surface 7 that contacts the sealing material 6. Has been previously subjected to corona discharge treatment.

Next, the adapter 8 is attached to the case opening of the module case 2 and filled with the liquid sealing material 6 (see FIG. 2C). In the present invention, since the wettability of the adhesive surface 7 of the hydrophobic air vent member 4 is enhanced, the liquid sealing material 6 spreads widely over the adhesive surface 7 of the air vent member 4 and the adhesive area is increased. It is possible to obtain high adhesive strength.

After the filled sealing material 6 is solidified, the unnecessary portion 9 is cut to open the end portion of each hollow fiber membrane 3 and the air passage portion 41 of the air vent member 4 to thereby open the hollow fiber membrane module. Is completed.

In the above embodiment, a layered air vent member formed by laminating two films is used as the air vent member. It can be used, and even in that case, the wettability can be improved and the adhesive strength can be increased by subjecting the adhesive surface to the sealing material to a surface treatment such as corona discharge treatment.

[0025]

[Effect of device]

 The present invention has the above-described configuration and operation. Since the adhesive surface of the air vent member that comes into contact with the sealing material is subjected to surface treatment to improve wettability, the adhesive strength of the sealing material is increased and the hollow fiber membrane is increased. It is possible to improve the pressure resistance of the module.

Further, since the peeling of the adhesive of the sealing material is less likely to occur, the product defect rate can be significantly reduced.

[Brief description of drawings]

1 shows a hollow fiber membrane module according to an embodiment of the present invention, in which FIG. 1 (a) is a partially broken vertical sectional view, FIG. 1 (b) is a side view, and FIG. 1 (c). 8D is an enlarged cross-sectional view of a main part of the hollow fiber membrane, and FIG. 8D is a plan view of the air vent member.

2 (a) to 2 (d) are explanatory views showing a manufacturing process of the hollow fiber membrane module of FIG.

FIG. 3 is an explanatory diagram for explaining a state of interfacial tension between a sealing material and an air vent member.

FIG. 4 is a vertical cross-sectional view of a conventional hollow fiber membrane module.

[Explanation of symbols]

 1 Hollow Fiber Membrane Module 2 Module Case 3 Hollow Fiber Membrane 31 Passage 32 Membrane Wall 4 Air Venting Member 41 Air Passing Section 42 Heat Welding Section 43 Film 5 Case Opening 6 Sealing Material 7 Adhesive Surface 8 Adapter 9 Unnecessary Parts

Claims (2)

[Scope of utility model registration request] 1. A large number of hydrophilic hollow fiber membranes and a hydrophobic air vent member are bundled and inserted into a module case, and the hollow fiber membrane, the air vent member and the module case are connected to each other at the opening of the module case. In a hollow fiber membrane module in which the gap is filled with a sealing material to bond and fix the hollow fiber membrane and the air vent member, in order to enhance the wettability of the sealing material on the adhesive surface of the air vent member with which the sealing material comes into contact. A hollow fiber membrane module characterized by being subjected to the surface treatment of. 2. The hollow fiber membrane module according to claim 1, wherein the surface treatment is corona discharge treatment.