JPH0798135B2 - Hollow fiber type membrane module and manufacturing method thereof - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a hollow fiber type membrane module in which impurities are hardly eluted and a method for producing the same, and more specifically, impurities are accumulated in a hollow fiber membrane in an adhesive sealing part. TECHNICAL FIELD The present invention relates to a hollow fiber type membrane module and a method for manufacturing the same.

[Conventional technology]

In recent years, there have been significant advances in membrane technology, including reverse osmosis,
Separation membranes having various separation characteristics such as microfiltration type and ultrafiltration type have been developed. Along with this, as membrane modules for accommodating membranes, those having various forms such as spiral type and hollow fiber type are manufactured according to various membranes.

Among them, the hollow fiber type membrane module is used in a wide range of fields because it is compact and has advantages such as a small priming volume. For example, in the field of electronics industry, it is used for ultrafiltration just before the point of use of ultrapure water.

Such a hollow fiber type membrane module has a length of 200 to 1000 m.
Thousands to tens of thousands of hollow fibers with m and outer diameter of 0.05 to 2 mmφ are bundled and inserted into a cylindrical case, and the ends are adhesively sealed mainly with an epoxy adhesive to cure and It is manufactured by cutting and then attaching a cap and the like.

By the way, once the membrane module thus obtained is contaminated with impurities or the like, it is not easy to discharge the impurities. Some of these impurities are contained in the liquid to be separated and some are generated from the constituent members in the module, etc., and remain in each part in the module to contaminate the filtrate.

Therefore, in the above manufacturing process, the members of the module, the sealant and the like are carefully selected in order to reduce the elution of impurities from the module. In addition, as for the structure of the module, a structure is adopted in which the vicinity of a seal portion such as an O-ring where impurities easily accumulate and the water retention portion between the permeate nozzle and the adhesive sealing portion are improved.

[Problems to be solved by the invention]

However, even if the components of the module are selected and the structure is improved as described above, the elution of impurities from the hollow fiber type membrane module may be a problem. According to the investigation conducted by the present inventors, it was found that such a portion where impurities are accumulated is inside the hollow fiber membrane that is adhesively sealed at the end of the container of the module.

Therefore, an object of the present invention is to develop a hollow fiber type membrane module in which impurities are not eluted from the hollow fiber type membrane module due to the above causes.

[Means for solving problems]

The present inventors have conducted extensive studies and research to solve the above problems, and as a result, when manufacturing a hollow fiber type membrane module,
We have succeeded in developing a hollow fiber type membrane module that can reduce the eluted impurities by preventing the impurities from accumulating in the hollow fiber in the sealant portion by the following treatment.

That is, the present invention provides a hollow fiber type membrane module in which both ends of a cylindrical container for accommodating a hollow fiber bundle separate and seal the hollow fibers from each other. The present invention provides a hollow fiber type membrane module having a surface that is impermeable to water.

Furthermore, the present invention also provides a method for producing the above hollow fiber membrane module.

In the present invention, making the hollow fiber water impermeable means that the filtrate is not substantially allowed to enter the porous portion on the surface of the hollow fiber membrane. Examples of such water-impermeable methods include, for example, a method of infiltrating the hollow fiber with a solvent, a method of applying or dipping an adhesive on the surface of the hollow fiber and then removing excess adhesive to cure the hollow fiber, and dipping the hollow fiber in water and then drying. In particular, in the method of the present invention in which an adhesive is applied to the inner surface of the hollow fiber, the inner surface of the hollow fiber is completely impermeable to water.
Great effect. The adhesive used is, for example, an epoxy adhesive or a urethane adhesive, and is not particularly limited to these and any adhesive may be used.

In the water-impermeable treatment as described above, the above-mentioned treatment is applied to the portion that is adhesively sealed after the membrane module is manufactured.

Examples of the material of the hollow fiber membrane used in the present invention include, but are not particularly limited to, polysulfone-based resin, polyether sulfone-based resin, polyimide resin, polyacrylonitrile resin, polymethylmethacryl resin or cellulose acetate-based resin. .

The material and shape of the membrane module are not particularly limited, and any one can be used.

In the present invention, the method for producing the membrane module other than the step of making the water impermeable is not particularly limited, and a usual production method can be used.

The hollow fiber type membrane module of the present invention obtained as described above, the porous portion of the inner surface of the hollow fiber membrane having the adhesive sealing portion is impermeable so that the filtrate containing impurities does not enter, Impurities do not accumulate in such portions.

〔Example〕

Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited thereto.

Example of manufacturing hollow fiber membrane module A bundle of 5000 hollow fibers made of polyethersulfone with an inner diameter of 500 μm and an outer diameter of 800 μm is inserted into a polysulfone case with an inner diameter of 89 mmφ, a thickness of 5 mm, and a length of 320 mm, which is centrifugally sealed. It was set in the machine and a heat resistant epoxy adhesive was injected and centrifugally sealed to cure. This was taken out, and after cutting the end portion of the case, the adhesive was sufficiently cured at 100 ° C.

Example 1 As shown in FIG. 1, epoxy adhesive 6 is applied to one end of the hollow fiber type membrane module obtained in the above production example so as to fill at least the hollow fiber 2 in the adhesive sealing portion. Immediately after that, pressurized air was sent from the other end of the case to discharge the excess epoxy adhesive 6 filled in the hollow portion of the hollow fiber. After wiping off the excess adhesive, the adhesive was heated to 90 ° C. and cured. After that, the other case end portion was treated in the same manner to make the hollow fiber membrane in the adhesive sealing portion impermeable to water.

The membrane module treated in this manner was subjected to the following tests in order to evaluate the retention of impurities.

The above hollow fiber type membrane module was filled with a 5% aqueous formaldehyde solution as an impurity and left at room temperature for 1 hour. Then, pure water is passed through the module at 25 ° C at a flow rate of 400 l / h (360 l / h on the permeate side and 40 l / h on the concentrated side) to determine the formaldehyde concentration of the permeate in the formaldehyde test Wako (Wako Pure Drug). The formaldehyde concentration 10 minutes after the start of water flow is shown in Table 1.

Comparative Example 1 A retention test with formaldehyde was conducted in the same manner as in Example 1 except that the membrane module obtained in the above Production Example was not subjected to the water-impermeable treatment. The results obtained are shown in Table 1.

From the results of the above test, in the membrane that has not been subjected to the water-impermeable treatment, the amount of impurities eluted is high, and the impurities are retained in the porous hollow fiber in the sealant portion of the membrane module. it is conceivable that.

〔The invention's effect〕

As described above, the hollow fiber type membrane module obtained by the present invention has very little elution of impurities, and is suitable for separation to obtain a high-purity product.

[Brief description of drawings]

FIG. 1 is a conceptual diagram showing how a hollow fiber is subjected to a water-impermeable treatment in Example 1. [Main reference numbers] 1 ... Hollow fiber type membrane module, 2 ... Hollow fiber, 4 ... Adhesive sealing part, 6 ... Adhesive

Claims (2)

[Claims] 1. A hollow fiber type membrane module in which both ends of a cylindrical container for accommodating a hollow fiber bundle are separated from each other and adhesively sealed, and an inner surface of the hollow fiber in the adhesively sealed portion. Is a water-impermeable hollow fiber membrane module. 2. A method for producing a hollow fiber type membrane module in which both ends of a cylindrical container for accommodating a hollow fiber bundle separate hollow fibers from each other and adhere and seal the hollow fiber type membrane module. A method for producing a hollow fiber type membrane module, characterized in that an adhesive is applied to the inner surface of the hollow fiber in the adhesive sealing portion and cured to make it impermeable.