JPH04334529A - Hollow yarn filter module - Google Patents

Abstract

PURPOSE:To still more efficiently perform washing due to an air valve by preventing the damage of hollow yarn membranes at the bonded part of the hollow yarn membranes and a fixing member to almost perfectly prevent the leak caused by said damage. CONSTITUTION:In a hollow yarn filter module having a bundled body of hollow yarn membranes 2 and a fixing member 1 for fixing the end parts of the hollow yarn membranes, the protective elastic resin layer 3 in which the base parts of the hollow yarn membranes the outer pheripheral part of the bundled body are embedded and the protective net material 4 covering the outer periphery of the bundled body at the base part thereof and suppressing the expansion of the bundled body are arranged.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hollow fiber filtration module for a water purifier, and more particularly to a hollow fiber filtration module in which the joint between a hollow fiber membrane and a fixing member is less likely to be damaged.

0002

2. Description of the Related Art Hollow fiber filtration modules are used in various fields because of their compactness, and in recent years, the range of their use has expanded, and it is desired that they be used under more severe conditions. For example, it may be used in hot water or hot water, and in this case, a material such as a heat-resistant epoxy resin is used as a fixing member for the hollow fiber membrane. However, because heat-resistant epoxy resin has a high hardness, the stress applied to the hollow fiber membrane when handling or using the hollow fiber filtration module is concentrated at the root of the hollow fiber membrane that connects to the fixing member, causing the hollow fiber membrane to break. Problems such as leakage occurred due to breakage occurred.

[0003] As a solution to such problems,
There are known those having a protective layer as described in JP-A-2-107318 and those having a protective body as described in JP-A-59-147603.

0004

[Problem to be solved by the invention] JP-A-2-1073
In the case of the protective layer described in Publication No. 18, no leakage was observed under normal water flow. However, under more severe conditions, for example, backwashing with air bubbles that cleans the outer surface of the hollow fiber membrane by shaking the hollow fiber membrane by applying air bubbles to the membrane causes damage to the root part of the hollow fiber membrane. It turned out that there was a problem with leaks. In addition, in the case of the protector described in JP-A-59-147603, although the hollow fiber membranes are prevented from expanding to the outer periphery of the hollow fiber bundle, diagonal cross-section of the hollow fiber membranes inside the protector is difficult. It was also ineffective against the occurrence of defects due to stress concentration near the root of the hollow fiber membrane due to vibration. When the hollow fiber membrane is covered with a protector over a wide range in its longitudinal direction, cleaning efficiency is not good even when vibration is applied to the hollow fiber membrane. When the protector was shortened to improve cleaning efficiency, leakage occurred due to vibration damage to the hollow fiber membrane.

[0005] An object of the present invention is to prevent leakage caused by breakage of the hollow fiber membrane, which tends to occur at the joint between the hollow fiber membrane and the fixing member during cleaning, without reducing the cleaning efficiency of the hollow fiber membrane. The objective is to provide a hollow fiber filtration module that can.

[0006]

[Means for Solving the Problems] That is, the hollow fiber filtration module of the present invention includes a bundle of multiple hollow fiber membranes and a fixing member that fixes the ends of the hollow fiber membranes while keeping them open. In the hollow fiber filtration module, a protective elastic resin layer embedding the root portion of the hollow fiber membrane at least on the outer periphery of the bundle is disposed in contact with a fixing member, and the outer periphery of the root portion of the bundle A protective net material that wraps the bundle and suppresses the spread of the bundle is fixed to the fixing member through the resin layer.

[0007]

[Operation] Hereinafter, the hollow fiber filtration module of the present invention will be explained in more detail with reference to the drawings.

FIG. 1 is a schematic sectional view showing an example of the hollow fiber filtration module of the present invention. The hollow fiber filtration module of the present invention basically includes a fixing member 1, a hollow fiber membrane 2,
It is composed of a protective elastic resin layer 3 and a protective net 4. In addition to these, members such as the annular member 5 may be attached, if desired, to function as a support member when installing the hollow fiber filtration module in the water purifier. In addition, in FIG. 1, illustration of the tip portion of the hollow fiber membrane is omitted.

The fixing member 1 focuses and fixes each end of a large number of hollow fiber membranes 2 while keeping them open, and also serves as a filtration membrane for water to be purified and purified water. It functions as a partition member from water. The fixing member 1 is generally made of hardened epoxy resin, unsaturated polyester resin, or the like.

Various materials can be used as the hollow fiber membrane 2, such as those made of various materials such as cellulose, polyolefin, polysulfone, polyvinyl alcohol, and PMMA. In addition, the hollow fiber membrane may be of the type in which the opening is fixed with a fixing member, the hollow fiber membrane may be converged into a U-shape, or one end of the linear membrane may be sealed. It may also be of the same type.

[0011] The protective elastic resin layer 3 protects the roots of the hollow fiber membranes (the portions located near the exposed fixing member of the hollow fiber membranes) at least in the outer peripheral portion of the bundle of multiple hollow fiber membranes. It is arranged so that it is buried. The protective elastic resin layer is
Usually, it is disposed in close contact with the fixing member, but it is not necessarily necessary to be disposed in close contact with it, and there may be some gap between it and the fixing member. However, if this gap is too large, the effect of providing the protective elastic resin layer will be weakened, and stress will again be concentrated at the root of the hollow fiber membrane in contact with the fixing member, which is not appropriate. As the resin used for the protective elastic resin layer 3, a resin having relatively high elasticity even after curing, such as urethane resin or silicone resin, is used.

The protective elastic resin layer 3 usually has a thickness of about 10 to 100
It is sufficient that the roots of the hollow fiber membranes located at least in the outer peripheral part of the bundle consisting of 000 hollow fiber membranes are buried;
The root portion of the hollow fiber membrane located in the center of the bundle does not necessarily have to be buried. The concentration of stress at the root portion of the hollow fiber membrane is noticeable at the outer periphery of the hollow fiber membrane due to the degree of freedom of movement of the hollow fiber membrane, so protection is particularly required at the outer periphery. Since the protective elastic resin layer 3 is made of a material that is more elastic than the fixing member and has a rigidity close to that of the hollow fiber membrane, it can function to relieve stress concentration at the root of the hollow fiber membrane. The thickness (depth) of the hollow fiber membranes in the outer peripheral portion of the bundle of the protective resin layer is preferably 1 to 30 mm, more preferably 3 to 10 mm.

The protective net 4 has the function of suppressing the spread of the bundle in the hollow fiber filtration module, but when the hollow fiber membrane comes into contact with the protective net due to shaking or vibration of the hollow fiber membrane, the hollow fiber membrane may It is preferable that the entire protective net material has flexibility so as not to be damaged, and has a perforated structure that does not affect the filtration performance of the hollow fiber membrane. Specific examples include net-like bodies, knitted and woven fabrics, perforated nonwoven fabrics, perforated films, and the like. As the material for the protective net material, organic polymers are preferred.

[0014] The protective net material is arranged at the base of the bundle of hollow fiber membranes so as to wrap around the outer periphery of the bundle. Usually, the protective net material is fixed to the fixing member in a state where it is buried to a depth of about 5 mm, and the root part of the bundle is passed through the protective elastic resin layer to a length of usually 1 to 100 mm, preferably 10 mm.
A length of ~30 mm surrounds the outer periphery of the bundle. If there is a wide gap between the protective net material and the bundle, it is not possible to suppress the expansion of the hollow fiber membrane, so usually at least a part of the protective net material is in contact with the hollow fiber membrane, preferably. The protective net material is placed so as to surround the outer periphery of the bundle in such a manner as to be in close contact with the hollow fiber membranes.

[0015]

[Examples] Hereinafter, the hollow fiber filtration module of the present invention will be explained in more detail with reference to Examples. Example 1 Both ends of a bundle consisting of 10,000 polyethylene porous hollow fiber membranes (EHF410C, trade name, manufactured by Mitsubishi Rayon Co., Ltd.) with a length of 50 mm were protected on an annular member 5 with an inner diameter of 79 mmφ and an outer diameter of 100 mmφ. Net material (TTX-
243 (trade name, manufactured by Nippon Netron Co., Ltd.) wrapped in epoxy resin (Epicoat ED834,
Product name: Yuka Shell Epoxy Co., Ltd., C950
, trade name, manufactured by Nippon Kayaku Co., Ltd. at a ratio of 13:2 (weight ratio)) was poured into the inner surface of the annular member and hardened to form a fixing member. At this time, the protective net material was exposed by about 20 mm from the end of the fixing member. Next, the root portion of the hollow fiber membrane at the outer periphery of the hollow fiber bundle is approximately 3 to 6 mm deep, and the root portion of the hollow fiber membrane at the center is approximately 2 to 5 m.
Silicone resin (KE-
1300T (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.), a protective elastic resin layer was formed to protect the joint end of the hollow fiber membrane and the fixing member, and a hollow fiber filtration module as shown in FIG. 1 was produced. The effective fiber length of one hollow fiber membrane is 1000 m.
It was m. Comparative Example 1 A hollow fiber filtration module was produced in exactly the same manner as in Example 1, except that the protective net material was not provided. Comparative Example 2 A hollow fiber filtration module was produced in exactly the same manner as in Example 1, except that the protective elastic resin layer was not provided. Comparative Example 3 A hollow fiber filtration module was produced in exactly the same manner as in Example 1, except that the protective net material was disposed so as to be exposed by about 500 mm from the end of the fixing member. Evaluation example Using the hollow fiber filtration modules obtained in Example 1 and Comparative Examples 1 to 3 above, 100 p of ferric oxide was applied at a constant linear flow rate.
Table 1 shows the evaluation results of the differential pressure of the hollow fiber filtration module after filtering water containing pm for one month and the differential pressure of the hollow fiber filtration membrane after functional recovery treatment was performed by backwashing with air bubbles. Ta.

[0016] Furthermore, after backwashing with air bubbles, air was blown into the outer surface of the hollow fiber membranes at a rate of 0.5 kg/cm2, and the number of hollow fiber membranes with air leaks in the module was measured. Table 1 shows the results. Ta.

[0017]

[Table 1]

[0018]

[Effects of the Invention] According to the present invention, damage to the hollow fiber membrane that is likely to occur at the joint between the hollow fiber membrane and the fixing member during use or cleaning of the hollow fiber filtration module is prevented, and leakage caused by this damage is almost completely eliminated. could be prevented. Furthermore, when cleaning this hollow fiber filtration module, the conventional method using air bubbles could be efficiently implemented.

[Brief explanation of drawings]

FIG. 1 is a schematic cross-sectional view showing an example of a hollow fiber filtration module of the present invention.

[Explanation of symbols]

1: Fixing member 2: Hollow fiber membrane 3: Protective elastic resin layer

Claims (1)

[Claims] 1. A hollow fiber filtration module comprising a bundle of a large number of hollow fiber membranes and a fixing member that fixes the ends of the hollow fiber membranes while keeping them open, wherein at least the outer periphery of the bundle A protective elastic resin layer embedding the root portion of the hollow fiber membrane is disposed in contact with the fixing member, and a protective net material wraps the outer periphery of the root portion of the bundle to suppress the spread of the bundle, A hollow fiber filtration module, characterized in that it is fixed to a fixing member via the resin layer.