JPH032008B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for treating the end face of a hollow fiber membrane separation module, and more particularly to a method for completely and easily repairing leak spots on the end face of the module.

Hollow fiber membrane separation modules are widely used for processing various industrial liquids and gases, for medical purposes, and as equipment for producing ultrapure water.

As such hollow fiber membrane separation module,
For example, the hollow fiber membranes and the cylindrical case housing them are adhesively fixed at both ends with casting resin,
It is known that a hollow fiber membrane is opened at the end face of the casting resin.

When separating liquids using the above module, the stock solution is supplied from one open end surface of the hollow fiber membrane, the concentrated liquid flows out from the other open end surface, and the obtained permeate is placed in a cylindrical case. The permeate is discharged from the permeate outlet. In this case, the stock solution and concentrated solution must not leak to the permeate side, and if leakage occurs, the performance of the module will deteriorate and it will become unusable. The cause of this leak is often due to poor adhesion between the casting resin, hollow fiber membrane, and cylindrical case at the ends, and therefore, it is necessary to repair this poor adhesion.

Conventionally, as the above-mentioned repair methods, repair methods using decompression method (Japanese Patent Application Laid-open No. 135675/1982) and repair method using pressurization method (Japanese Patent Application Laid-Open No. 138874/1989) have been proposed.
In these methods, the opening of the hollow fiber membrane is blocked during repair, so the end must be further cut to open the hollow fiber membrane, which is very complicated and disadvantageous in terms of cost. It had the disadvantage of being

The present invention has been made to solve the drawbacks of the prior art, and provides a method for repairing the end face of a module without blocking the opening of the hollow fiber membrane.

That is, the present invention provides a module in which a plurality of hollow fiber membranes are bonded and fixed to each other with a casting resin at both ends of a plurality of hollow fiber membranes bundled in parallel. A hollow fiber membrane separation module characterized in that the repair casting resin is transferred to the end face of the casting resin by pressing a repair material having a peelable and uniform repair casting resin layer on the surface. The present invention relates to an end surface treatment method.

The repair material used in the present invention is one in which a layer of repair casting resin is removably and uniformly provided on the surface of a foam made of rubber or synthetic resin, and the repair casting resin is applied to a module. It is designed so that it can be transferred to the end face of the mold resin.

In order to manufacture such a repair material, a repair casting resin layer can be directly provided on the surface of a foam having releasability, but from the viewpoint of uniformity and releasability of the resin layer, it is manufactured by the following operation. is preferable.

That is, first, a repair casting resin is uniformly applied to the surface of a sheet-like object so that the resin layer has a thickness of about 50 to 200 μm. The above-mentioned sheet-like material may be any material having a smooth surface and capable of providing a uniform resin layer in a releasable manner, such as a plastic sheet made of polypropylene, polyethylene, Teflon, polyvinyl chloride, etc. is used. Next, the repair casting resin layer provided on the sheet-like material is transferred onto the surface of the foam. The foam may be any material as long as the resin layer can be peeled off from the sheet-like material to provide a uniform resin layer on the surface of the foam and can also be transferred to the end face of the casting resin of the module, such as rubber or It is sufficient to use a foam made of synthetic resin or the like which has been subjected to hydrous treatment or mold release treatment. In this way, a repair material can be obtained in which a repair casting resin layer is releasably and uniformly provided on the surface of the foam.

In the present invention, by pressing the above-mentioned repair material against the casting resin surface on the hollow fiber membrane opening side of the module, the repair casting resin is peeled off from the foam surface and transferred to the above-mentioned end surface, filling the defective adhesion area. be done. On the other hand, at the opening of the hollow fiber membrane, the repair casting resin does not come into contact with it and remains attached to the foam surface.
It will not enter the opening.

The above-mentioned repair casting resin may be any resin that can be uniformly provided on the surface of the foam so that the resin layer can be peeled off, and those having a viscosity of usually 200 to 10,000 cp, preferably 500 to 2,000 cp can be used. The viscosity
If the viscosity is less than 200 cp, it will be difficult to uniformly apply a resin layer of the specified amount, and if the viscosity is more than 10,000 cp, the hollow fiber membrane opening will be damaged when the repair material is pressed against the end face of the cast resin of the module. There is a possibility that even the resin layer in the opening may be peeled off and the resin may enter the opening.
The material of the repair casting resin is not particularly limited, but it is preferable to use the same type of casting resin as the module, such as epoxy resin or urethane resin.

Furthermore, in the present invention, when the repair material is pressed against the end face of the cast resin of the module, if the outside of the hollow fiber membrane is reduced in pressure (usually 300 to 750 mmHg),
The repair casting resin can be more effectively filled into areas with poor adhesion.

As described above, according to the present invention, a repair material in which a repair casting resin layer is releasably and uniformly provided on the surface of a foam is pressed against the casting resin end face on the hollow fiber membrane opening side of the module. In particular, since the repair casting resin can be transferred to the end face without blocking the hollow fiber membrane opening, there is an advantage that defective adhesion on the end face of the module can be completely and easily repaired.

Hereinafter, the present invention will be specifically explained with reference to Examples.

Example 3,700 polysulfone hollow fiber membranes with an inner diameter of 500 μm and a membrane thickness of 250 μm were housed in a vinyl chloride cylindrical case with an inner diameter of 77 mm and a length of 1077 mm, and both ends were adhesively fixed with epoxy resin. After the resin solidified, the hollow fiber membranes were Both ends were cut open to obtain a hollow fiber membrane separation module.

When a leak test was conducted by supplying pressurized gas to the outside of the hollow fiber membrane of this module, it was found that the pressure of the pressurized gas had decreased and a leak point had occurred.

Therefore, an epoxy resin with a viscosity of 1000 cp is uniformly applied as a repair casting resin onto a polypropylene sheet so that the resin layer has a thickness of 70 to 150 μm, and then this epoxy resin is applied to a polyurethane sheet impregnated with water. A repair material was created by transferring it to foam. Thereafter, this repair material was pressed against the cast resin end face of the module, and the epoxy resin was transferred to the end face and solidified. At this time, the outside of the hollow fiber membrane is
The pressure was reduced to 300 mmHg.

A leak test was conducted again on the module whose end face had been treated as described above, but no leakage points were observed. Further, the openings of the hollow fiber membranes were not blocked in any way.

Claims (1)

[Claims] 1. A repair tool is applied to the surface of the foam on the end face of the casting resin on the opening side of the hollow fiber membrane of a module in which the hollow fiber membranes are adhesively fixed to each other with casting resin at both ends of a plurality of hollow fiber membranes bundled in parallel. A method for treating an end face of a hollow fiber membrane separation module, comprising transferring a repair casting resin to the end face of the casting resin by pressing a repair material having a peelable and uniform casting resin layer.