JPH09225269A - Two-layer centrifugal joining method of hollow fiber membrane module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the reinforcing effect of joining boundary by injecting a flexible resin from the inside of an adhesive layer into the inner part of a fiber bundle without stopping the revolution of a centrifugal joining machine after the injection of an adhesive is completed. SOLUTION: The flexible resin such as a silicone resin is injected without stopping the revolution of the centrifugal joining machine after the injection of the adhesive such as an epoxy resin from an adhesive injection cup 5 and an injection tube 6 is completed. At the time of injecting, both of the cup 5 for the adhesive and a cup 8 for the flexible resin are set in the centrifugal joining machine to inject into the module, the adhesive is injected while a passage of an injection tube 9 of the flexible resin is interrupted with an air cylinder 12 or the like by compressed air provided in the rotary shaft of the centrifugal joining machine and after the injection of the adhesive is completed, the flexible resin is injected by removing the interruption of the injection line of the flexible resin. As a result, the occupation time of the centrifugal joining machine is reduced and the flexible resin enters even the center of the fiber bundle with the increased temp. to reinforce the joining boundary.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for centrifugally adhering a hollow fiber membrane module. More specifically, it relates to a two-layer centrifugal bonding method in which the hollow fiber membrane at the bonding interface is reinforced with a flexible resin.

[0002]

2. Description of the Related Art Hollow fiber membrane modules are generally used for reverse osmosis membranes, ultrafiltration membranes, microfiltration membranes, etc. because of their large membrane area per unit volume. When assembling the hollow fiber membrane module, first, seal the open end of the hollow fiber membrane, and then fix the adhesive between the hollow fiber membranes and between the hollow fiber membrane and the case by centrifugal adhesion, and then The part is cut and the end of the hollow fiber membrane is opened to form a module.
It is preferable to inject the adhesive from the end of the yarn bundle and to make the thickness of the bonded portion constant and to overflow from the hole of the nozzle portion of the module in order to complete sterilization and sterilization.

Epoxy resin or urethane resin is generally used as the adhesive, but since the adhesive has a high viscosity, it passes between the case with a large gap and the yarn bundle and overflows from the nozzle portion, and then the yarn. Invade the bundle.
Therefore, the adhesive interface is located at a position lower than the nozzle portion, and the adhesive is thinly coated on the lowered portion to cure.

The hollow-fiber membrane where the adhesive is thinly coated hardens because it hardens in contact with the air and is fragile. In addition, the nozzle serves as an inlet / outlet for the stock solution and the filtrate. If the conditions are severe, the film may break at the adhesive interface. In particular, recently, in the condensate treatment and decontamination treatment of clean water in a nuclear power plant, a method of vibrating the solid content adhering to the film with air to shake it off is used. Reinforcement is important.

For this reason, in Japanese Utility Model Laid-Open No. 61-132002 and Japanese Patent Laid-Open No. 61-157308, it is proposed to reinforce this portion with a flexible resin. For two-layer bonding, the centrifugal bonding machine bonds while rotating,
It is difficult to provide electric piping or the like in the centrifugal bonding machine, and two-layer bonding has not been performed without stopping the centrifugal bonding machine.

Therefore, when performing two-layer bonding, the centrifugal bonding machine is stopped after the adhesive has hardened, and then the flexible resin is set and injected. In the hollow fiber membrane module,
If the curing of the adhesive is accelerated, the heat generation temperature of the curing of the adhesive becomes high, and it may be necessary to slow down the curing of the adhesive as much as possible because cracking of the adhesive part and peeling from the case occur. The above curing time is required. Also,
Since the flexible resin is used only to reinforce the adhesive interface, the amount of the resin is small, and even if the resin temperature is raised, heat is taken away to the surroundings, the curing time becomes long, and it is necessary to reinforce the flexible resin. A large module required a total bonding time of 10 hours or more.

[0007]

DISCLOSURE OF THE INVENTION According to the present invention, when the adhesive and the flexible resin are bonded in two layers without stopping the centrifugal bonding machine, the exclusive time of the centrifugal bonding machine is shortened. , So that the flexible resin can go deep into the yarn bundle,
An object of the present invention is to provide a two-layer centrifugal bonding method for hollow fiber membrane modules, which can enhance the reinforcing effect of the bonding interface.

[0008]

The inventors of the present invention have conducted extensive studies to solve the above-mentioned problems, and as a result, introduced compressed air into the rotary shaft of a centrifugal bonding machine and injected the adhesive with this compressed air. After the completion, if the flexible resin is injected without stopping the centrifugal adhesive machine, the adhesive and the flexible resin can be cured almost at the same time, and the adhesive layer has a high temperature. The inventors have found that not only the curing time of the flexible resin is accelerated, but also the flexible resin penetrates deep into the yarn bundle and has a great effect of reinforcing the adhesive interface, thus completing the present invention.

That is, the present invention provides a hollow fiber membrane module in which the ends of a large number of hollow fiber membranes are fixed with an adhesive and the inside of the adhesive layer is covered with a flexible resin to reinforce the hollow fiber membranes. In the layer centrifugal bonding method, after the injection of the adhesive is completed, the flexible resin is injected from the inside of the adhesive layer without stopping the rotation of the centrifugal bonding machine. In the layer centrifugal adhesion method and the flexible resin injection, the injection of the flexible resin is delayed by temporarily interrupting the injection with compressed air provided on the rotation shaft of the centrifugal adhesive machine. It is the above-mentioned two-layer centrifugal adhesion method.

In the present invention, the adhesive is one generally used for fixing hollow fiber membranes such as epoxy resin and urethane resin, and the flexible resin is more than the adhesive. It needs to be a soft material, and has flexibility such as urethane resin and silicon resin. In the present invention, the hollow fiber membrane may be made of any material, but it is particularly effective to use it for a membrane having hardness and small elongation such as polysulfone and polyacrylonitrile.

After the injection of the adhesive has been completed, the method of injecting the flexible resin without stopping the rotation of the centrifugal adhesive machine is a method for injecting the adhesive cup and the flexible resin into the centrifugal adhesive machine. Both of the cups are set so that they can be injected into the module, and the compressed air provided on the rotary shaft of the centrifugal bonding machine shuts off the flow path of the flexible resin injection tube with an air cylinder or the like. After the injection of the adhesive is completed, the blocking of the injection of the flexible resin may be released and the flexible resin may be injected.

The injection of the adhesive is usually completed in about 10 minutes, but it is more effective to inject the flexible resin after the adhesive is gelated and does not mix with the adhesive. It is preferable to perform the injection 20 to 120 minutes after the start of the injection. If the injection of the flexible resin is too early, the adhesive and the flexible resin will be mixed, and the reinforcing effect will be small, and if it is too late, the flexible resin will start to harden and the flexible resin will enter the yarn bundle. It will not enter and the reinforcing effect will be lost.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described specifically with reference to examples, but the present invention is not limited to these examples.

[0014]

Example 1 A 5-inch PVC module case (1) with a molecular weight cut-off of 13,000 and an outer diameter of 1.35 mm.
4800 hollow fiber membranes (2) made of polyacrylonitrile whose opening is sealed with are filled, and the bonding jig (3) is fixed by the holding jig (4) as shown in FIG. 3) Adhesive injection cup (5) and injection tube (6) at the end
Connected. A flexible resin injection cup (8) and an injection tube (9) were attached to the nozzle (7) of the module case (1) and set in a centrifugal bonding machine.

Then, the adhesive injection cup (5) is filled with 30
The two-component epoxy resin (10) at a temperature of 0 ° C. is filled, and the flexible resin injection cup (8) is filled with the two-component silicone resin (11) at a temperature of 30 ° C. It was pressed by the air cylinder (12) so that the flexible resin was not injected even when the centrifugal bonding machine was rotated. Next, the inside of the centrifugal bonding machine was kept at 35 ° C. and rotated at 50 G for bonding. When the epoxy resin (10) was observed with a stroboscope, the injection was completed in 9 minutes.

After 40 minutes from the start of rotation of the centrifugal bonding machine, the pressing of the air cylinder (12) was released and the silicone resin (11) was injected. Five and a half hours after the start of rotation, the centrifugal adhesive machine was stopped and the module was taken out. As a result, the epoxy resin and the silicone resin were cured to such an extent that neither flowed. Also, the silicone resin has entered the center of the yarn bundle.

[0017]

[Comparative Example 1] In the same manner as in Example 1, when only the epoxy resin was injected and the centrifugal adhesion time was stopped at 5 hours and 5 hours and a half, the curing was insufficient in 5 hours and the epoxy resin flowed and the adhesion occurred. The shape of the agent layer could not be maintained, but that for 5 and a half hours did not flow.

[0018]

[Comparative Example 2] The module manufactured in Comparative Example 1 with a centrifugal bonding time of 5 hours and a half was set in a centrifugal bonding machine, and as in Example 1, 30 ° C was applied from the nozzle (7) of the module case (1).
5 hours and a half later, the centrifugal adhesive machine was stopped and the module was taken out. The curing of the silicone resin was insufficient and the silicone resin flowed, and the shape could not be maintained.

When the centrifugal adhesion time was set to 6 hours, the silicone resin was hardened, but the silicone resin entered only the middle part of the yarn bundle.

[0020]

As described above, it is possible to set the adhesive and the flexible resin for reinforcing the adhesive interface in the centrifugal bonding machine at the same time, and do not stop the centrifugal bonding machine after the injection of the adhesive is completed. By injecting the flexible resin, the exclusive time of the centrifugal bonding machine can be significantly shortened. Further, when the flexible resin is injected, the temperature of the adhesive is high, so that the flexible resin enters the central portion of the yarn bundle and is effective in reinforcing the adhesive interface.

[Brief description of drawings]

FIG. 1 is a conceptual diagram of module manufacturing according to the method of the present invention.

[Explanation of symbols]

 1 Module Case 2 Hollow Fiber Membrane 3 Adhesive Jig 4 Holding Jig 5 Adhesive Injection Cup 6 Adhesive Injection Tube 7 Nozzle 8 Flexible Resin Injection Cup 9 Flexible Resin Injection Tube 10 Adhesive (Epoxy Resin) 11 Yes Flexible resin (silicon resin) 12 Air cylinder

Claims (2)

[Claims] 1. A two-layer hollow fiber membrane module in which the ends of a large number of hollow fiber membranes are fixed with an adhesive and the inside of the adhesive layer is covered with a flexible resin to reinforce the hollow fiber membrane at the adhesive interface. In the centrifugal bonding method, after the injection of the adhesive is completed, the flexible resin is injected from the inside of the adhesive layer without stopping the rotation of the centrifugal bonding machine, which is a two-layer centrifugation of the hollow fiber membrane module. Bonding method. 2. The injection of the flexible resin is delayed by temporarily interrupting the injection with compressed air provided on the rotary shaft of the centrifugal bonding machine. The two-layer centrifugal adhesion method described in 1.