JPS62144708A - Hollow yarn mold membrane module - Google Patents

Abstract

PURPOSE:To eliminate cutting troubles caused by breaks of hollow yarn at the interface between the hollow membrane and the adhesive by introducing as protective layers the non-deflective adhesive having swelling effect against hollow yarn for the first stage and the deflective adhesive without swelling effect for the next stage. CONSTITUTION:At the end of a hollow yarn type membrane module, the non- deflective layer 3 having partly swelling effect against the hollow yarns 1 such as epoxy adhesive and the like for the first stage and the deflective adhesive layer 2 having swelling effect against hollow yarn 1 such as urethane-based adhesive and the like for the next stage are provided. The non-deflective adhesive having a high adhesive strength is cured to which each of hollow yarns 1 is adhered and, after arranging the said adhering section to receive most of the working forces during operation, part of the hollow yarn deteriorated during curing process with the non-deflective adhesive is allowed to come into the protective coating layer by introducing the deflective adhesive as protective coating layer and cured. Through the said process, provided a force of lateral direction acts on the hollow yarn, the protective layer is not transformed to prevent the hollow yarn from being sharply curved.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Industrial Application Field The present invention relates to a hollow fiber membrane module made of polysulfone or polyethersulfone. More specifically, the present invention includes a layer of an inflexible epoxy adhesive in which the adhesive sealing part has the effect of partially swelling the hollow fibers, and a layer of flexible adhesive that does not have the effect of swelling the hollow fibers. The present invention relates to a hollow fiber membrane module having a structure in which the layers are arranged in layers in the length direction of the module, thereby improving the strength of the hollow fibers at the interface between the adhesive sealing part and the hollow fibers in the module.

(b) Conventional technology The semipermeable membrane module, which is the heart of reverse osmosis and ultrafiltration equipment, is of various types depending on the application, one of which is a hollow fiber membrane. Modules are widely used in various fields because of their compactness and small priming volume.

This hollow fiber membrane module has a length of 300 to 1000 mm.
.

Thousands to tens of thousands of hollow fibers with an outer diameter of about 0.1 to 2 mm are bundled together, inserted into a cylindrical case, and the ends are adhesively sealed with a non-flexible epoxy adhesive. After curing. The cap is then manufactured by cutting to open the end and for trimming, and then attaching the cap by gluing, welding, or screwing. Conventionally, epoxy adhesives have been used alone to adhesively seal the ends of such hollow fiber membrane modules.

(c) Problems to be Solved by the Invention However, this epoxy adhesive has the effect of partially swelling or dissolving polysulfone or polyethersulfone hollow fibers. This will be explained in detail below.

A force of 20 g is applied to one polyethersulfone hollow fiber with a breaking strength of 130 (), and the middle part of this hollow fiber is heated to 70°C with Epicoat 82, an epoxy base agent.
8 (registered trademark, Yuka Shell 1FJ), about 1
It was cut at the point where it was attached in 0 minutes. Similarly 80℃
When applied to Epikote 828, it was cut in about 2 minutes. Next, a similar experiment was carried out using Epicote 815 (registered trademark, manufactured by Yuka Shell Co., Ltd.), which was cut at 50° C. in about 2 minutes. Similar experiments were conducted with polysulfone hollow fibers, which broke several times faster than polyethersulfone hollow fibers.

Considering the above, it can be seen that polysulfone and polyether sulfone are swollen by epoxy, and the speed of this swelling is faster as the temperature is higher, and that they are dissolved by epoxy over a long period of time. However, epoxy adhesives are generally used because they have high heat resistance and strong adhesive strength. This is because the above-mentioned swelling effect is a problem only when the adhesive is in liquid form, and once it hardens, this effect disappears. In reality, hollow fiber membrane modules are made by curing the agent. However, this method partially degrades the hollow fibers. The biggest problem at that time occurs at the interface between the hollow fiber and the adhesive. In the adhesive part, the hollow fibers are firmly supported by the adhesive and there is no problem, but deterioration of the interface between the hollow fibers and the adhesive part becomes a problem when force is applied to the hollow fibers.

Another problem when using epoxy adhesives is that
Epoxy adhesive is non-flexible. At the interface between the adhesive and the hollow fibers, the adhesive creeps up between the hollow fibers due to capillary action, as shown in FIG. This height is inversely proportional to the distance between the hollow fibers. The tip of the hollow fiber is an interface between the hollow fiber and the part surrounded by adhesive from the outside. If a lateral force is applied to the hollow fiber above this interface, the hollow fiber will break with a very weak force. This is thought to be because the epoxy adhesive is inflexible and has little ability to deform and release force. This causes the hollow fiber module to become very weak. That is, by passing water through the module, a lateral force is applied to the hollow fibers, and this also causes problems when the hollow fiber module is dropped and subjected to impact (due to carelessness). Furthermore, in steam sterilization performed by aeration of live steam, a gas-liquid interface between water and steam may occur, resulting in severe bubbling.
This causes the yarn to be violently shaken, and there is also a risk that the hollow fiber may break. As described above, when used, there is a risk that the hollow fibers may be cut at the adhesive interface, leading to leaks. In view of this situation, the present inventors have completed the present invention as a result of intensive studies.

(d) Means for solving the problem and its effect The present invention is characterized in that a cylindrical case is filled with a hollow fiber bundle, and adhesive is applied between the hollow fibers and between the ends of the hollow fiber bundle and the end of the case. A hollow fiber membrane module that is adhesively sealed in a hollow fiber type membrane module, in which the configuration of the adhesive layer of the adhesive sealing portion causes each hollow fiber to partially swell from the longitudinal end of the module toward the center of the module. A hollow fiber type characterized in that a non-flexible adhesive layer that has a function is arranged in one stage and a flexible adhesive layer that does not work to swell the hollow fibers is arranged in the next stage. It is a membrane module.

That is, in the present invention, each hollow fiber is bonded by curing a non-flexible adhesive with a high adhesive strength, and after this bonded portion has the majority of the force acting during use, the hollow fibers are bonded together. A flexible adhesive that does not swell the yarn is introduced as a protective coating layer and then cured. This allows the portion of the hollow fiber that deteriorated during the curing of the epoxy adhesive to enter the protective coat layer, and because the protective coat layer is flexible, lateral force acts on the hollow fiber. Since the protective coating layer is not deformed and the hollow fibers are not bent at an acute angle, the hollow fibers are extremely resistant to bending.

(e) Example Next, the present invention will be explained using FIG. Note that the present invention is not limited to this.

FIG. 1 is an explanatory view of the main part configuration showing one embodiment of the hollow fiber membrane module according to the present invention, that is, a schematic vertical cross-sectional view of the end of the module (M), (1) shows the individual hollow fiber membranes, (2)
(1) is a highly heat-resistant, flexible two-layer adhesive layer that does not have the effect of swelling the hollow fibers, and (3) is a non-flexible adhesive layer that has the effect of partially swelling the hollow fibers. The step epoxy adhesive layer (4) is a cylindrical case, which is usually made of acrylic resin, folysulfone resin, vinyl chloride resin, or FRP.

As the adhesive for the adhesive layer (2), in terms of chemical properties, an adhesive containing a soft segment and having a urethane bond, an adhesive having a siloxane bond, etc. are selected. Next, the adhesive for the next adhesive layer (2) and the first adhesive layer (3)
Describe the innermost ratio of each adhesive. Generally, when sealing the end of a hollow fiber membrane module (M) with adhesive, it is necessary to
Calculate the amount of adhesive and inject it so that the length is ~100 nun. This bonding length depends on the size of the module (M), especially the inner diameter of the cylindrical case (4) and the hollow fiber (1
) can be lengthened or shortened as appropriate depending on the filling rate, etc.

If this adhesive length is too short, the pressure applied to Mogicol (M) during operation is b1 to 10ka4 in the case of ultrafiltration, so it will not be able to withstand this pressure, and the adhesive adjacent to the hollow fiber (1) will not be able to withstand this pressure. parts are destroyed. Furthermore, if this length is made longer than necessary, the effective filtration area of the hollow fibers (1) will decrease and the efficiency of the entire module (M) will decrease.

Among these bonding lengths, the bonding length of adhesive layer (2) is 1 to 4
0% is preferred.

Here, the effects of the hollow fiber membrane module (M) described above will be explained using a specific example.

Specific example 1 A polyether sulfone hollow fiber with a breaking strength of 130 g was subjected to a force of 20 g, and the middle part of this hollow fiber was dipped in urethane adhesive at 90°C, but it did not break even after 1 hour. Ta. Similarly, it was soaked in a silicone adhesive at 90°C, but it did not break.

Specific example 2 A polysulfone cylindrical case with an inner diameter of 82 mmφ, an outer diameter of 90 mmφ, and a length of 320 mm has an inner diameter of 500 seats and an outer diameter of 70 mm.
Insert a fiber bundle consisting of 6,400 0fiπ polyethersulfone hollow fibers, set it in a centrifugal sealing machine, and use epoxy adhesive at a temperature of 50°C and a rotational speed of 90 rpm to bond one side to a length of 25 mm. After curing, centrifugal sealing was performed under the same centrifugal conditions using a silicone adhesive so that the adhesive length on one side was 5 mm. After this was completed as a module as shown in Figure 1, steam at a temperature of 130℃ and water at a temperature of 25℃ were alternately heated for 100 minutes.
After the loop was passed through (the hollow fiber was shaken quite violently at this time), an inspection after the completion revealed no leakage caused by the adhesive interface.

Comparative Example 1 The same procedure as in Example 1 was carried out except that the silicone adhesive of Example 2 was not used. When steam was passed three times, cracks occurred at the interface between the hollow fiber and the adhesive, resulting in a leak. Occurred.

(F) Effects of the Invention The hollow fiber membrane module according to the present invention can be manufactured by introducing a specific adhesive layer serving as a protective coat layer into the next stage, unlike the conventional hollow fiber membrane having only one adhesive layer. Compared to modules, cutting troubles due to hollow fiber bending can be prevented.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of the main part configuration showing one embodiment of the present invention, and FIG.
The figure is an explanatory diagram showing a state in which adhesive creeps up between hollow fibers. (M)...Hollow fiber membrane module, (1)...
...Hollow fiber, (2)...1 layer of adhesive layer, (3)...2 layer of adhesive layer, (4)...Cylindrical shape Case. Figure 2

Claims (1)

[Claims] 1. A hollow fiber type in which a cylindrical case is filled with a hollow fiber bundle, and the spaces between the hollow fibers and between the ends of the hollow fiber bundle and the end of the case are adhesively sealed. A non-flexible membrane module in which the adhesive layer of the adhesive sealing part has the effect of partially swelling each hollow fiber from the lengthwise end of the module toward the center of the module. A hollow fiber membrane module characterized in that an adhesive layer is disposed in one stage and a flexible adhesive layer that does not swell the hollow fibers is disposed in the next stage. 2. The hollow fiber membrane module according to claim 1, wherein the hollow fibers are made of polysulfone or polyethersulfone. 3. The hollow fiber membrane module according to claim 1, wherein the first adhesive layer is made of an epoxy adhesive, and the next adhesive layer is made of an adhesive having a urethane bond. 4. The hollow fiber membrane module according to claim 1, wherein the first adhesive layer is made of an epoxy adhesive, and the next adhesive layer is made of an adhesive having a siloxane bond.