JPH0810591A - Method for coating end of hollow-fiber membrane - Google Patents

Abstract

PURPOSE:To conduct good patting regardless of the kind of a hollow-fiber membrane at the time of coating the end of the bundle of the membranes by rotating the bundle and injecting a coating agent into the end of the bundle. CONSTITUTION:When the end of the bundle of hollow-fiber membranes 6 is coated, the bundle is rotated, and a coating agent is injected into the end of the bundle. Namely, the coating agent is centrifugally applied on the end of the membrane 6, the excess coating agent is centrifugally shaken off, and the impregnation with the coating agent is prevented. Further, a coating of optional thickness is applied at an optional position by adjusting the application position, viscosity and centrifugal force (revolving speed) of the agent. Consequently, the partial coating of the hollow-fiber membrane which has been difficult in the state of long fiber immediately after filature, is ideally applied. Further, a hollow-fiber membrane module without generating an impermeable fiber and using the membrane area efficiently is produced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hollow fiber membrane coating apparatus, and more particularly to a hollow fiber membrane coating apparatus for coating the end portions of a plurality of hollow fiber membranes prior to manufacturing a hollow fiber membrane module. Is.

[0002]

2. Description of the Related Art Conventionally, a hollow fiber membrane module has a large effective membrane area per unit volume as compared with a spiral type module or a tubular type module, and water treatment relations such as microfiltration and ultrafiltration, nitrogen, It is used in numerous fields such as gas separation related to oxygen and hydrogen, chemical related, bio related. However, in order to modularize this hollow fiber membrane, it is necessary to hermetically seal (potting) between the hollow fiber membranes and the hollow fiber membranes and between the hollow fiber membranes and the module container at the ends. Currently, most of the potting materials for the end plates of this module are urethane-based or epoxy-based adhesives.The potting method uses gravity to fill the module ends with gravity. Examples include a placing method, a vacuum method of accelerating filling by decompression, and a centrifugal molding method of filling by utilizing centrifugal force. Among them, the centrifugal molding method is often used. By using this method, the potting material is sufficiently filled even in a small gap of the hollow fiber membrane by centrifugal force, and the hollow fiber membrane can be ideally fixed and sealed. Also, urethane type,
Epoxy adhesives are relatively easy to adjust the initial viscosity, the time and temperature required for curing, and are easy to pot.

[0003]

However, since the centrifugal molding method applies a very large centrifugal force (usually 10 times or more of gravity) as compared with gravity, especially when the hollow fiber membrane is a porous membrane, The potting material easily penetrates into the inside of the hollow fiber membrane through the pores of the hollow fiber membrane, so that a so-called "impervious fiber" is likely to occur. Currently, the most common methods for preventing non-threading include increasing the viscosity of the potting material, decreasing the rotational speed to reduce the centrifugal force, pretreating the potting part of the hollow fiber membrane, and the like. If the viscosity of the potting material is increased, it becomes difficult for the potting material to permeate between the hollow fibers, and a so-called "impermeable" state is likely to occur.
Also, even if the centrifugal force is lowered, "impermeability" tends to occur,
It is not always a good idea because the potting surface may be inclined due to the influence of gravity. The potting part of the hollow fiber membrane is heat treated in advance (Japanese Patent Laid-Open No. 61-97005),
A method of closing the pores by coating the ends in advance has also been considered, but heat treatment is
It is easy to deteriorate in shape and requires high technology, and when the hollow fiber membrane is immersed in a liquid for both heat treatment and coating,
When the hollow fiber membranes are bundled, the liquid permeates between the hollow fiber membranes, and it is difficult to control the area to be immersed in the liquid, which is not a suitable means. It is an object of the present invention to provide a hollow fiber type module manufacturing means capable of performing good potting regardless of the type of hollow fiber membrane.

[0004]

The present invention is a method for coating the ends of a hollow fiber membrane bundle, which comprises rotating the hollow fiber membrane bundle and injecting a coating agent into the ends of the hollow fiber membrane bundle. It is basically achieved by a hollow fiber membrane bundle end coating method characterized by

That is, the coating agent can be applied to the end of the hollow fiber membrane by centrifugal force, and the excess coating agent can be shaken off by the centrifugal force, so that the coating agent can be prevented from bleeding. Further, by adjusting the coating position of the coating agent, the viscosity, and the centrifugal force (rotation speed), it is possible to apply the coating of any thickness to any position.

As a result of the present invention, it becomes possible to ideally perform partial coating of a hollow fiber membrane, which has been difficult to perform in the state of a long yarn immediately after spinning.

As an example of the present invention, based on FIG.
As described below, the present invention is not limited thereto.

FIG. 1 is a sectional view of an example of the hollow fiber membrane coating apparatus of the present invention. The hollow fiber membrane 6 is a turntable 9
It is rotated by the motor 10 while being placed on the table.
On the other hand, the coating agent is supplied from the coating agent tank 1 through the supply port 2 to the coating agent container 3 while the apparatus is rotating. The supplied coating agent is discharged from the nozzle 4 toward the hollow fiber membrane 6 and applied to the hollow fiber membrane. The surplus portion of the applied coating agent is expelled to the outside by the centrifugal force, and finally shaken off. The excess coating agent that has been shaken off is collected in the excess coating agent reservoir container 8.

The number of revolutions and the magnitude of centrifugal force are appropriately selected depending on the purpose, the viscosity characteristics of the coating agent, the conditions such as the length of the hollow fiber, and are not particularly limited. Taking into consideration the permeability of the coating agent, the rotation limit of the motor, and the like, an approximate value is preferably indicated, and the centrifugal force at the end to be coated is preferably 5 to 10
0G, more preferably 10 to 50G.

Of course, the coating agent in the present invention is not particularly limited, and any coating agent may be used according to the purpose. However, it is preferable that the solution can have a relatively low viscosity because coating can be easily performed. Further, a hollow fiber membrane used or one that modifies or dissolves the potting material is not desirable, and it is better not to be invaded by a target substance to be separated later.

Further, depending on the coating conditions, it is possible to set various conditions such as temperature / humidity control, exhaust, and inert gas atmosphere. This may enclose the device or, if circumstances permit, make the entire room suitable for coating.

As the coating agent, a very large number can be mentioned such as silicone, nylon, polyacrylonitrile, rubber-like polymer such as ethylene propylene rubber and neoprene rubber.

Examples of the hollow fiber membrane in the present invention include homogeneous hollow fiber membranes, porous hollow fiber membranes, composite hollow fiber membranes, etc., but are not particularly limited. However, even for the purpose of the present invention, the case of the porous hollow fiber membrane which is most likely to cause impermeability is most applicable. Further, it is also effective when coating as a so-called bond role for improving the adhesiveness between the hollow fiber membrane and the potting material.

Specific examples of these hollow fiber membranes include solvent-resistant polyacrylonitrile porous hollow fiber membranes, polyimide porous hollow fiber membranes, polyethersulfone porous hollow fiber membranes, polyphenylene sulfide sulfone porous hollow fiber membranes. Porous hollow fiber membranes such as polytetrafluoroethylene porous hollow fiber membranes, polypropylene porous hollow fiber membranes, polyethylene porous hollow fiber membranes, etc., and crosslinked silicone, polybutadiene as a functional layer for these porous hollow fiber membranes, Examples thereof include a composite hollow fiber membrane in which a rubber-like polymer such as polyacrylonitrile butadiene, ethylene propylene rubber, and neoprene rubber is compounded, and a homogeneous hollow fiber membrane such as a crosslinked silicone tube.

In the hollow fiber membrane coating apparatus shown in FIG. 1, both ends of the hollow fiber membrane are shown to be coated. However, when it is desired to coat only one of the hollow fiber membranes depending on the shape of the module, the nozzle 4 should be provided with a hollow fiber membrane end portion. In addition to using only one of the above, by setting a plurality of hollow fiber membranes as shown in FIG. 2, it becomes possible to coat many hollow fiber membranes at the same time. FIG. 3 is a top view showing an example of how to set the hollow fiber membranes. In this case, the nozzle 4
Will be provided for each bundle.

Further, in FIGS. 1, 2 and 3, the hollow fiber membrane is directly
Although it is set in the device, as shown in FIG. 4, there is no particular problem even when it is loaded in the module case 11. In this case, the module case needs to have a hole for applying the coating agent, but in general, the nozzle 12 is often provided as a fluid inlet / outlet port, which often causes no problem.

[0017]

The present invention will be described more specifically with reference to the following examples. However, the present invention is not limited to this.

Example 1 Hollow fiber membrane 50 having an outer diameter of 450 μm, an inner diameter of 350 μm and a length of 500 mm
A bundle of 0 polyacrylonitrile porous hollow fiber membranes with an inner diameter of 20
It was inserted into a polystyrene module container having a length of mm and a length of 450 mm and set in the hollow fiber membrane coating apparatus of the present invention. After that, while rotating at a rotation speed of 200 rpm, a cross-linking silicone liquid was injected as a coating agent from two nozzles located 180 mm from both ends from the center of the module container.
The coating was removed by coating and centrifugal force. After the coating is completed, it is dried thoroughly and then the conventional centrifugal molding method is used to rotate Coronate 4403 at 1000 rpm.
Nipporan 4226 (manufactured by Nippon Polyurethane Co., compounding ratio 53:47
) Was used for sealing and potting.

After the completion, both ends of the potting fixing portion were cut and the hollow fiber membrane inner hole was opened to manufacture a module having an effective length of 400 mm. External pressure 0.5k using the obtained module
When a pure water permeation test was conducted at gf / cm ² , the water permeation rate was 0.82k.
It was g / min.

Comparative Example 1 A hollow fiber membrane module was manufactured under the same conditions as in Example except that the hollow fiber membrane coating was immersed in the coating solution as a bundle in a static state, and the obtained module was the same as that in Example. When evaluated under the conditions, the water permeation rate was 0.68 kg / min.

Comparative Example 2 When a hollow fiber membrane module was manufactured under the same conditions as in Example except that the hollow fiber membrane was not coated, more than half of the hollow fiber membranes became impermeable and the obtained module was used as an example. When evaluated under the same conditions, the water permeation rate was 0.27 kg / min.

[0022]

As described above, according to the present invention, it is possible to manufacture a hollow fiber membrane module which is excellent in performance and which does not cause a non-threading and wastes the membrane area.

[Brief description of drawings]

FIG. 1 is a side sectional view of an example of a hollow fiber membrane coating apparatus according to the present invention.

FIG. 2 is a side sectional view of an example of an apparatus for coating only one end of a hollow fiber membrane according to the present invention.

FIG. 3 is a top view of an example of a turntable used in the hollow fiber membrane coating apparatus according to the present invention.

FIG. 4 is a cross-sectional view of an example of a general hollow fiber membrane module container.

[Explanation of symbols]

 1: Coating agent tank 2: Coating agent supply port 3: Coating agent reservoir container 4: Coating agent injection nozzle 5: Hollow fiber membrane fixing jig 6: Hollow fiber membrane 7: Excess coating agent recovery vessel 8: Excess coating agent vessel 9 : Turntable 10: Motor 11: Module case 12: Nozzle

Claims (5)

[Claims] 1. A method for coating the end of a hollow fiber membrane bundle, wherein the hollow fiber membrane bundle is rotated and a coating agent is injected into the end of the hollow fiber membrane bundle. Membrane bundle end coating method. 2. The method for coating a hollow fiber membrane bundle end portion according to claim 1, wherein an excess of the injected coating agent is removed from the hollow fiber membrane bundle end portion by centrifugal force. 3. The hollow fiber membrane bundle end coating method according to claim 1, wherein the coating agent is dripped into a coating material container that rotates together with the hollow fiber membrane bundle. 4. The method for coating the end portion of a bundle of hollow fiber membranes according to claim 1, wherein a cross-linking silicone liquid is used as a coating agent. 5. A potting method characterized in that, when potting the end portion of the hollow fiber membrane bundle, the end portion of the hollow fiber membrane bundle is coated with the coating method according to any one of claims 1 to 4.