JPH01218605A - Hollow fiber type filtration module - Google Patents

Abstract

PURPOSE:To improve chemical resistance and heat resistance of a filtration module by arranging a large number of hollow fibrous semi-permeable membranes almost linearly in an outer casing and by making use of a thermoplastic resin raw material in at least wetted parts of module members. CONSTITUTION:A large number of hollow fibrous semi-permeable membranes 1 are arranged almost linearly in an outer casing 4, which has an outlet port 2 for a permeating liquid and an inlet port 3 for a liquid to be treated. Both and parts of the hollow fibrous semipermeable membranes are bundled, fused together with a thermoplastic resin of the same raw material as that of the semi-permeable membranes and sealed within the outer casing 4. Then, a filtration module is completed by attaching cap parts 11 of outer casing. The chemical resistance and heat resistance of the module is improved, because at least wetted parts of members constituting the module are thus made of the thermoplastic resin.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a filtration module for fluid separation using a hollow fiber semipermeable membrane, and furthermore, the entire module has chemical resistance and heat resistance equivalent to that of the semipermeable membrane. The present invention relates to a filtration module for fluid separation that has high properties, low elution properties, and cold and heat hysteresis properties.

(Conventional technology and its problems) Hollow fiber semipermeable membranes used for reverse osmosis, ultrafiltration, and microfilters are economical because they have a large membrane area per unit volume when modularized, and are It has excellent features such as it is easy to maintain the filtration rate by using flow and backwashing, and there are no foreign substances such as spacers or strength supports on the secondary side, making it easy to maintain a clean state.
It is used in various fields such as food. Conventionally, hollow fiber semipermeable membranes have been modularized by liquid-tightly fixing the ends of the hollow fibers with a thermosetting resin 12 and bonding and/or O-ring sealing them to the outer cylinder. A sectional view of an example module is shown in FIG. Epoxy resins, epoxy acrylic resins, urethane resins, and the like are used as the thermosetting resin 12, but these have the following drawbacks, which limit their range of application.

1) In recent years, fluororesin has been proposed as a heat-resistant and chemical-resistant hollow fiber semipermeable membrane material. It is not possible to take advantage of the performance of the semipermeable membrane.

11) Thermosetting resins use crosslinking agents or curing agents, so they can completely suppress the elution of unreacted low-molecular substances. In the semiconductor field, which dislikes elution, even lower elution properties are required.

iii) Since the thermosetting resin and the outer cylinder are made of different materials and have different coefficients of thermal expansion, peeling may occur between the outer cylinder and the thermosetting resin when the module is alternately exposed to high-temperature fluid and low-temperature fluid. Problems such as cracks in the thermosetting resin may occur.

(Objective of the Invention) The object of the present invention is to solve the above-mentioned problems by providing a hollow fiber semipermeable membrane that does not reduce its inherent heat resistance, chemical resistance, low elution property, and cold and heat resistance. An object of the present invention is to provide a hollow fiber type filtration module.

(Structure of the Invention) The hollow fiber filtration module of the present invention has a plurality of hollow fiber semipermeable membranes arranged substantially linearly in an outer cylinder having at least one permeate fluid outlet and a population of the fluid to be treated. The present invention is characterized in that at least the liquid-contact parts of the members constituting the module are made of thermoplastic resin, preferably made of the same material. Furthermore, in the module, at least the hollow fiber semipermeable membranes are connected to each other or between the hollow fibers through a sealing member made of the same material as the hollow fibers, or between the hollow fibers and the sleeves, or between the hollow fibers and the sleeves. The hollow fiber is characterized by being thermally fused in a liquid-tight manner via a sealing member made of the same material as the hollow fiber to form an open end. Furthermore,
The sleeve, the outer cylinder, the body of the outer cylinder, and the cap are liquid-tightly heat-sealed to each other or between each member through a sealing member made of the same material as the member. .

In addition, in a module having only one open end, such as a module used in the external pressure filtration method, the hollow fiber end on the opposite side of the open end must be sealed liquid-tightly. It is also characterized in that the hollow fiber-like semipermeable membrane is heat-sealed to each vehicle, or the ends of the hollow fibers are heat-sealed to the sealing plate.

(Embodiments and Effects) Hereinafter, the outline of the embodiments of the present invention will be shown in the drawings, but the present invention is not limited to the scope thereof.

The first example of the module in which the hollow fiber semipermeable membrane, the sleeve, the body of the outer cylinder part, and the cap part are all heat-sealed in a liquid-tight manner is shown below.
Shown in Figures (A) to (C). An example in which only the body of the outer cylinder and the cap are sealed by a method other than heat fusion is shown in FIGS. 2A and 2B. An example in which the body of the outer cylinder part and the cap and the outer cylinder part and the sleeve are sealed by a method other than heat fusion is shown in FIGS. 3A and 3B.

The semipermeable membrane of the present invention includes reverse osmosis membranes, ultrafiltration membranes, microfilters, etc., which are conventionally known as membrane separation techniques.

Thermoplastic resin is suitable as the material for the hollow fiber semipermeable membrane of the present invention because it can be thermally bonded. For example, polyolefins such as polyethylene and polypropylene, fluororesins such as polyvinylidene fluoride, ethylene-tetrafluoroethylene copolymer, and tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer; polyvinyl chloride; nylon; polyester; polysulfone; polyether Sulfone; PEEK etc. can be mentioned.

When sealing the body of the outer cylinder part and the cap, if thermal fusion is not possible, for example, a method using a conventionally known rolling method can be used, and the surface of a rubber rolling material with appropriate elasticity is sealed with a hollow fiber-like semipermeable membrane. It may be used by coating with the same material.

Example 1 As a semipermeable membrane, hollow fiber polysulfone (manufactured by Asahi Kasei Kogyo (Shikiku)) having specifications shown in Table A was used.

First, one open end of this hollow fiber semipermeable membrane was
Sealing was performed according to the method described in Publication No. 4.3390. However, the material used for sealing was calcium carbonate. Approximately 5g of calcium carbonate was caught on line for 2m.
The mixture was kneaded in β and applied to one open end of the hollow fiber semipermeable membrane to seal it.

The sealed length is the depth to which the sealing material packed into one open end of the hollow fiber semipermeable membrane has penetrated, and in this example, the sealing length is approximately 5Qm
I set it to m.

The sealed ends of 100 hollow fiber semipermeable membranes were arranged and bundled, and an adhesive tape manufactured by Nippon Baliki Co., Ltd. was wrapped around the outer periphery of the bundle. At this time,
The gaps between the hollow fiber semipermeable membranes in this bundle were filled with fine powder made of the same material as the semipermeable membrane material.

Then, this end portion was placed in a 250° C. furnace and held for about 5 minutes, and then slowly cooled, and the sealing tape wrapped around the outer periphery was removed.

Furthermore, this melt-bonded bundle was inserted into a hollow cylindrical sleeve made of the same material as the semipermeable membrane material.

The inner diameter of the sleeve was adjusted so that the gap between this bundle and the inner diameter of the hollow cylinder was Q, 4 mm or less. Then, fill the gap with fine powder made of the same material as the semipermeable membrane material.
This bundle inserted into the sleeve was again placed in the oven at 250°C, held for about 5 minutes, and then slowly cooled. Thereafter, the sealing material was removed using concentrated hydrochloric acid at 50°C.

At this stage, the sleeve and the hollow fiber semipermeable membrane are heat-sealed. In the same way, the opposite end is heat-sealed as shown in Fig. 8 (A
A filtration element shown in L (B) was manufactured.

The filter element was inserted into the body of the outer cylinder. Adjust the inner diameter of the body so that the gap between the outer diameter of the sleeve and the inner diameter of the body is Q,4 tva or less, fill the gap with fine powder of the same material as the semipermeable membrane material, and heat it again at 250°C. It was placed in a furnace and held for about 7 minutes, and then gradually cooled. A rolling type outer cylinder cap part was set on the outside of the body part to create a hollow fiber type filtration module as shown in the conceptual diagram of FIG. 2A.

(Table D) Module specification example 2 The semipermeable membrane is a hollow fiber ETFE with the specifications shown in Table B.
(manufactured by Asahi Kasei Kogyo ■) was used.

First, one open end of this hollow fiber semipermeable membrane was
Sealing was performed according to the method described in Publication No. 43.390. However, the material used for sealing was a mixture of 1=5 by weight of baked stone and calcium carbonate, which was dispersed in water. ml and applied to one open end of the hollow fiber semipermeable membrane to seal it.

The sealed length is the depth to which the sealing material packed into one open end of the hollow fiber semipermeable membrane has penetrated, and in this example, the sealing length is about 50 meters. I made it so that

The sealed ends of the 100 hollow fiber semipermeable membranes were arranged and bundled, and an adhesive tape manufactured by Nihon Bariki Co., Ltd. was wrapped around the outer periphery of the bundle. At this time,
The gaps between the hollow fiber semipermeable membranes in this bundle were filled with fine powder made of the same material as the semipermeable membrane material.

Then, this end portion was placed in a furnace at 290° C. and held for about 5 minutes, and then slowly cooled, and the 4J sealing tape wrapped around the outer periphery was removed.

Further, this melt-bonded bundle was inserted into a hollow cylindrical sleeve made of the same material as the semipermeable membrane material.

The inner diameter of the sleeve was adjusted so that the gap between this bundle and the inner diameter of the hollow cylinder was 0.4 mm or less. Then, fill the gap with I-Atsushi powder, which is made of the same material as the semi-membrane material, and with this bundle inserted into the sleeve, both are fixed from the outside with sealing tape and heated again at 290°C. It was placed in a furnace and held for about 5 minutes, and then slowly cooled.

At this stage, the sleeve and the hollow fiber semipermeable membrane are heat-sealed. In the same manner, the opposite end was heat-sealed to produce the filter element shown in FIG. 8.

The filter element was inserted into the body of the outer cylinder. Adjust the inner diameter of the body so that the gap between the outer diameter of the sleeve and the inner diameter of the body is 0.4 degrees or less, fill the gap with fine powder of the same material as the semipermeable membrane material, and heat it again at 290°C. Put it in the furnace, about 5
After holding for a minute, it was slowly cooled. A rolling type outer cylinder cap part was set on the outside of the body part to produce a hollow fiber type filtration module as shown in the conceptual diagram of FIG. 2(A).

(Table B) Specifications of Hollow Fiber Type Semipermeable Membrane (Table 1Σ) Module Specifications Example 3 As the semipermeable membrane, hollow fiber polyethylene (manufactured by Asahi Kasei Industries, Ltd.) with specifications shown in Table C was used.

First, one opening L1◇:11 of this hollow fiber semipermeable membrane was sealed according to the method described in Japanese Patent Publication No. 53-4.3390. However, the material used for sealing is a mixture of sintered stone and calcium carbonate in a weight ratio of 1:5, dispersed in water, and specifically about 1 g of sintered stone.
and about 5 g of calcium carbonate were mixed together in a 2.5 d fishing rod and applied to one open end of the hollow fiber semipermeable membrane to seal it.

The sealed length is the depth to which the sealing material packed into one open end of the hollow fiber semipermeable membrane has penetrated, and in this example, the sealing length is approximately 5Qm+
I made it to be i.

The sealed end of the sealed 100-wood hollow fiber semipermeable membrane was adjusted and bundled, and adhesive tape manufactured by Nippon Haruki Co., Ltd. was wrapped around the outer periphery of the bundle. At this time,
The gaps between the hollow fiber semipermeable membranes in this bundle were filled with fine powder made of the same material as the semipermeable membrane material.

Then, put this end in a 190°C oven and
After holding for a minute, it was slowly cooled and the sealing tape wrapped around the outer periphery was removed.

Furthermore, this melt-bonded bundle was inserted into a hollow cylindrical sleeve made of the same material as the semipermeable membrane material.

The inner diameter of the sleeve was adjusted so that the gap between this bundle and the inner diameter of the hollow cylinder was 0.4 mm. Then, a fine powder made of the same material as the semipermeable membrane material was filled into this gap, and this bundle, inserted into the sleeve, was placed in the oven at 190°C again, kept for about 15 minutes, and then slowly cooled. .

At this stage, the sleeve and the hollow fiber semipermeable membrane are heat-sealed. In the same way, the opposite end is heat-sealed as shown in Fig. 8 (A
) and (B) were manufactured.

The filter element was inserted into the body of the outer cylinder. Adjust the inner diameter of the body so that the gap between the outer diameter of the sleeve and the inner diameter of the body is 0.4 or less, fill the gap with fine particles made of the same material as the semipermeable membrane material, and heat it again in an oven at 190°C. about 15
After holding for a minute, it was slowly cooled. Thereafter, the sealing material was removed using concentrated hydrochloric acid at 50°C. A rolling type outer cylinder cap part was set on the outside of the body part to create a hollow fiber type filtration module shown in the conceptual diagram of FIG. 2(A).

(Table F) Module Specifications (Comparative Example 1) A module was created using the conventional adhesive technology with the same effective membrane area and other specifications as the module created in Example 2.

The module is ST- manufactured by Asahi Kasei Corporation except for the effective membrane area.
It is the same module as 309.

5T-309 Specifications (Table 1) Each module was immersed in 70'CX 27% ammonia water to evaluate chemical resistance. The results are shown in Table 2.

Table 2 Ammonia immersion test (weight change rate; %) The open end of the module of Comparative Example 1 swelled with ammonia and deteriorated.
On the other hand, the module of Example 2 showed the same chemical resistance as the hollow fiber, and the change in physical properties was rated as ○.

(Comparative Example 2) A module was created using a conventional bonding technique with the same effective membrane area as the module created in Example 1 and the same other specifications.

The module is manufactured by Asahi Kasei Kogyo @ Kiku 5I except for the effective membrane area.
It is the same module as P-3013.

SIP-301,3 Specifications (Table 3) Thermal and thermal tests 1 to 1 were simultaneously conducted for each module.

Test I/Conditions 1) Heating time 90℃ hot water x 15 minutes ii
) Cooling time: 5°C cold water x 15 minutes iii) Experimental flow, see Figure 7 iv) Filtration pressure: 1 kg/c The results are shown in Table 4.

Table 4 Cold/heat cycle test results (observation of open end) In the module of Comparative Example 2, stress was generated due to the difference in thermal expansion coefficient between the outer cylinder part (polysulfone) and the adhesive (epoxy resin), and the adhesive at the open end Cracks occurred and the fluid to be treated and the permeate fluid could no longer be separated, making it unusable. In contrast, no change was observed in the module of Example 1.

(Comparative Example 3) Modules were prepared in the same manner as in Comparative Example 1. After filling each module with 35% hydrogen peroxide and leaving it at room temperature, T, O,
C, (total organic carbon content) was measured with a T, O, C, meter (@Shimadzu Corporation, TOC-500).

Renew the hydrogen peroxide solution once a day, T, 0. C.

The decreasing trend was measured. (Limit of quantification - several PPm) Table 5
T, 0. C, measurement results) (PPm) In the module of Comparative Example 3, the number PP, which reached the limit of quantification, was finally reached at the third elution.
In contrast, the module of Example 1 showed a low value of several ppm or less in the first elution test, and the elution was essentially zero.

(Effects of the invention) As shown in the comparative example, according to the hollow fiber filtration module of the present invention, all the components constituting the module have the same heat resistance, chemical resistance, and low elution properties as the hollow fiber semipermeable membrane.・The module has improved safety and reliability due to its cold and heat resistance.
It is possible to expand the scope of application.

BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1 to 3 are conceptual diagrams showing embodiments of the hollow fiber filtration module of the present invention. FIG. 4 is a conceptual diagram of a cross section of the eastern end of a hollow fiber in which hollow fiber semipermeable membranes are heat-sealed to each other. FIG. 5 is an explanatory view in longitudinal section of a state in which a hollow fiber-like semipermeable membrane is heat-sealed and sealed at its ends. FIG. 6 is an explanatory diagram of a module manufactured by a conventionally known method of bonding hollow fiber bundles with a thermosetting resin. FIG. 7 shows a flow sheet of the thermal cycle test device. FIG. 8 is a conceptual diagram showing one embodiment of the module of the present invention. 2 is a hollow fiber semipermeable membrane, 2 is a permeate fluid outlet, 3 is an inlet and/or outlet of the fluid to be treated, 4 is an outer cylinder part of the module, 5 is a hollow fiber semipermeable membrane;
6 is an example of a hollow fiber type filtration module, 6 is an open end where the hollow fibers are heat-sealed to each other and the hollow fiber and the sleeve, 7 is a protective cylinder of a hollow fiber semipermeable membrane, 8 is an example of a sealing plate, and 9 is an example of a sealing plate. sleeve, 10
Reference numeral 11 indicates a body portion of the outer cylinder, 11 a cap portion of the outer cylinder, 12 an adhesive portion made of thermosetting resin, 13 a hot water tank, 14 a cold water tank, and 15 a liquid pump. Patent applicant Asahi Kasei Industries, Ltd.

Claims (8)

[Claims] (1) In a hollow fiber filtration module 5 in which a large number of hollow fiber semipermeable membranes 1 are arranged approximately linearly in an outer cylinder 4 having at least one permeate fluid outlet 2 and an inlet 3 for a liquid to be treated, the module is A hollow fiber filtration module characterized in that at least the wetted parts of all the constituent members are made of a thermoplastic resin material. (2) The constituent members of the module consist of a hollow fiber-like semipermeable membrane, an outer cylinder part, and an open end part 6, and a protective cylinder 7 as necessary.
The hollow fiber type filtration module according to claim 1, characterized in that it has: (3) The module according to claim 1, wherein the constituent members of the module are comprised of a hollow fiber semipermeable membrane, an outer cylinder part, an open end part, and a sealing plate 8, and further includes a protective cylinder if necessary. Hollow fiber filtration module (4) Hollow fiber-like semipermeable membranes or between the hollow fibers and the hollow fibers through a sealing member made of the same material as the hollow fibers, and between the hollow fibers and the sleeve 9 or between the hollow fibers and the sleeves. 2. The hollow fiber filtration module according to claim 1, wherein the open end is formed by liquid-tight heat-sealing via a sealing member made of the same material. (5) In the hollow fiber semipermeable membranes on the side opposite to the open end of the hollow fiber filtration module, each hollow fiber semipermeable membrane is individually sealed by heat fusion, or a bundle of hollow fiber semipermeable membranes is sealed. The hollow fiber type filtration module according to claim 1 or 4, wherein the hollow fiber filtration module is heat-sealed to the sealing plate. (6) The sleeve and the outer cylindrical portion are heat-sealed in a liquid-tight manner either directly or through a sealing member made of the same material as the sleeve. Hollow fiber filtration module described in 4. (7) The body part 10 of the outer cylinder part and the cap part 11 are heat-sealed in a liquid-tight manner either directly or through a sealing member made of the same material as the body part and the cap part. The hollow fiber type filtration module according to claim 1, 4 or 6, wherein (8) The hollow fiber filtration module according to claim 1, wherein the thermoplastic resins are made of the same material.