JPH07251039A - Reinforcement of bonding interface of hollow yarn membrane modules - Google Patents

Abstract

PURPOSE:To prevent the breakage of a hollow yarn membrane at a bonding interface by providing holes to the circumferential end part of a module case in two stages and closing the outside hole by centrifugal adhesion while allowing an adhesive to overflow from the outside hole and subsequently injecting a flexible resin from the inside hole. CONSTITUTION:Holes 2 are provided to a case 1 at a 180 deg. interval at two places so that the outer peripheral parts of the holes come to the circumference of the case 1 and four holes 3 are provided to the circumference of the case 1 at a 90 deg. interval inside the holes 2 so that a distance is provided from the holes 2 and the center axes of both holes are shifted by 45 deg.. Both end parts are fixed by the press jigs 8 of bonding jigs 7 and adhesive injection tubes 9 and adhesive cups 10 are fixed to the bonding jigs 7 and centrifugal adhesion is performed while an adhesive is allowed to overflow from the holes 2. Next, the holes 2 are sealed with a vinyl tape and a flexible resin is injected from the holes 3 to perform centrifugal adhesion and allowed to overflow from the holes 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for reinforcing a bonding interface of a hollow fiber membrane module. More specifically, it relates to a method of reinforcing a hollow fiber membrane at an adhesive interface 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 module is cut by cutting the end and opening the end of the hollow fiber membrane. In general, the adhesive is injected from the end of the yarn bundle or from the side, and in order to keep the thickness of the bonded portion constant, the adhesive is generally overflowed from the hole of the nozzle portion of the module or the like and bonded.

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 before the yarn bundle. Invade inside. 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.

Since the hollow fiber membrane is thinly coated with an adhesive and hardens because it cures in contact with air, it is not sufficiently cured and is very brittle. In addition, the nozzle serves as an inlet / outlet for the stock solution and the filtrate. Frequently, the thread rolls and breaks easily. For this reason,
No. 02 and Japanese Patent Application Laid-Open No. 61-157308 propose reinforcing this portion with a flexible resin.

[0005]

However, since the flexible resin must be injected from the hole of the case such as the nozzle portion, the flexible resin also overflows from the nozzle, and the adhesive becomes thin. The coated part cannot be completely covered and the reinforcing effect is reduced.
Therefore, it is also possible to inject the flexible resin by partially or completely closing the hole of the nozzle portion, but this method partially closes the hole of the nozzle portion, and it looks unpleasant or the undiluted solution of the nozzle portion. Alternatively, there is a problem that the flow of the filtrate is deteriorated.

[0006]

Means for Solving the Problems As a result of intensive studies for solving the above-mentioned problems, the present inventor provided two holes at the circumferential end of the module case and overflowed the adhesive from the outer holes. It was found that the hollow fiber membrane can be fixed to the case by performing centrifugal adhesion while being carried out, then the hole can be closed, and the flexible resin can be injected from the hole inside the hole, and the present invention has been completed. It was

That is, according to the present invention, in the method of reinforcing the adhesive interface of the hollow fiber membrane module with the flexible resin, the adhesive is injected until it overflows from the hole on the circumference of the case, and the case and the hollow fiber are sealed. After the adhesive is cured, the hole is closed, and then a flexible resin is injected from a hole on the inner circumference of the hole to reinforce the adhesive interface of the hollow fiber membrane module.

The term "adhesive" as used herein is generally used for fixing hollow fiber membranes such as epoxy resin and urethane resin, and the term "flexible resin" means a material softer than the above adhesive. It is necessary that the rubber has elasticity such as urethane resin and silicon resin.
The hole for overflow of the adhesive is provided on the circumferential side surface of the module case. However, when the module case has a nozzle, it is provided on the circumference closer to the end than the nozzle. 1 to several holes, preferably 1 to 2 holes may be provided. The size of the hole varies depending on the viscosity of the adhesive and the number of hollow fiber membranes filled, but is usually 3 mm or more, preferably 5 to 10 mm.
If it is good.

On the other hand, the hole for injecting the flexible resin may be utilized if there is a nozzle, and if there is no nozzle, the diameter is about the same as that for providing a normal nozzle. By doing so, it is possible to play a role of a nozzle by fixing an injection hose or the like to the hole later. Since the flexible resin is preferably as thin as possible within the range of completely covering the portion where the adhesive is thinly coated on the hollow fiber membrane, the effective area of the membrane is increased, so that the hole is a hole for adhesive overflow. It is necessary to shift the axis on the circumference. The holes for the overflow of the adhesive and the holes for injecting the flexible resin are provided such that the shortest distance between the circumferences of the former and the latter is 3 to 15 mm, preferably 5 to 10 mm (A in FIG. 3).
Distance).

The injection of the adhesive and the flexible resin is performed as follows. (1) The adhesive is first injected until it overflows from the adhesive overflow hole (the injection port is, for example,
It is provided at the end of the case as shown in FIG. ) The case, the hollow fibers, and the hollow fibers are adhesively cured with the remaining adhesive. (2) The hole is closed, and then the flexible resin is injected from the hole for injecting the flexible resin, which is provided on the inner circumference of the hole,
Inject and cure until the entire adhesive surface is coated.

As a method for closing the overflow hole of the adhesive, the same member as the case may be welded or sealed with a vinyl tape or the like and then filled with the injected flexible resin. The adhesion and the reinforcement may be performed while they are allowed to stand, but in order to make the adhesion surface and the resin-filled surface uniform, centrifugal adhesion and centrifugal reinforcement are preferable. The specific procedure may be performed based on a known method.

[0012]

EXAMPLES The present invention will be described below with reference to specific examples, but the present invention is not limited to these examples.

[0013]

EXAMPLE 1 As shown in FIG. 1, a hole 2 having a diameter of 5 mm is formed so that the outer peripheral portion of the hole comes on the case circumference of 40 mm from both ends of the transparent 1B PVC case 1 (that is, B in FIG. 3). The distance is 40mm) Two pieces are provided at intervals of 180 °, the distance between the outer circumferences of the holes is 10mm, and the center axes of both holes are offset by 45 °. Four 10 mm holes 3 were provided at intervals of 90 °. Furthermore, using a module case in which screws 4 for fixing an adhesive jig are provided on the outer peripheries of both ends of the case, the outer diameter is 0.98 m.
m, an inner diameter of 0.70 mm and a water permeability of 12,000 liters / m ² · Hr · at 25 ° C. made of polysulfone hollow fiber membranes 5 and a pipe 6 having an inner diameter of 8 mm as a water collecting pipe.
A module was manufactured using one of the above.

As shown in FIG. 2, the module has a bonding jig 7 fixed to both ends by pressing jigs 8, and the bonding jig 7 is fixed.
The tube 9 for injecting the adhesive and the adhesive cup 10 are fixed to the hole 2, and the epoxy resin 11 is provided in the hole 2 provided outside the case 1.
Centrifugal adhesion was performed while further overflowing. The epoxy resin 11 was cured at a position 5 mm lower than the lower surface of the hole 2 of the case.

Next, the hole 2 provided in the case was sealed with a vinyl tape, the silicone resin 12 was injected from the hole 3 provided inside the hole 2 of the case, and centrifugally adhered, and overflowed from the hole 3. The silicone resin 12 was cured at a position 1 mm lower than the lower surface of the hole 3. After curing, the adhesive jig and the pressing jig were removed, and the end face of the case was cut to obtain a module hollow fiber membrane.

The effective length of this module hollow fiber membrane is 220
A filtrate collection chamber was installed at one end at 0 mm, and external pressure total filtration was performed.
When the filtrate was withdrawn from the opposite side of the water collection chamber, the water permeation rate was 30.7 liter / min · kg / cm ² · at 33 ° C. This module was backwashed with the filtrate 5 times at an air pressure of 3 kg / cm ² , but the hollow fiber membrane was not broken.

[0017]

Comparative Example 1 A module was manufactured in the same manner as in Example 1, but when the epoxy resin 11 was centrifugally adhered, the hole 2 of the case was previously sealed with vinyl tape and overflowed from the hole 3 of the case. The epoxy resin 11 is used in Example 1.
Similarly to the above, the resin was cured at a position 5 mm lower than the lower surface of the hole 3 of the case.

Then, as in the first embodiment, the hole 3 in the case is formed.
A silicone resin 12 was further injected, centrifugally adhered, and overflowed from the hole 3 of the case to manufacture a module.
The silicone resin 12 was cured at a position 1 mm lower than the lower surface of the hole 3. The water permeation rate of this module is 30.2 liters / minute · kg / cm ² · at 33 ° C.
When the filtrate was backwashed with an air pressure of 3 kg / cm ² as in the above, 12 hollow fiber membranes were broken. The broken hollow fiber membranes were all generated at the opening of the hole 3 and at the portion where the silicone resin was thinly coated on the epoxy resin.

[0019]

According to the present invention, since the adhesive interface of the hollow fiber membrane can be reliably protected by a simple method, the hollow fiber membrane will not be broken. Further, since the flow of the stock solution and the filtrate is not hindered, it is possible to prevent the amount of the filtrate from decreasing and the hollow fiber membrane from being damaged.

[Brief description of drawings]

1A is a conceptual view of a module case of the present invention, FIG. 1B is a sectional view taken along the line AA ′ in FIG. 1A, and FIG. 1C is a sectional view taken along the line BB ′ in FIG.

FIG. 2 is a conceptual diagram showing a reinforcing method of the present invention.

FIG. 3 is an enlarged view of a module case end portion of the present invention.

[Explanation of symbols]

 1 Case 2 Holes (for Adhesive Injection) 3 Holes (Flexible Resin) 4 Screws 5 Hollow Fiber Membrane 6 Water Collection Tube 7 Adhesive Jig 8 Holding Jig 9 Tube 10 Adhesive Cup 11 Epoxy Resin 12 Silicone Resin

Claims (1)

[Claims] 1. A method for reinforcing an adhesive interface of a hollow fiber membrane module with a flexible resin, in which an adhesive is injected until it overflows from a hole on a circumference of a case to bond and cure the case and the hollow fiber. Thereafter, the hole is closed, and then a flexible resin is injected from a hole located on the inner circumference of the hole, to reinforce the bonding interface of the hollow fiber membrane module.