JPH0410371B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a method for treating overused modules using porous hollow fibers.

More specifically, the present invention relates to a method of hydrophilizing only the hollow fibers in an arbitrary portion of a module using hydrophobic porous hollow fibers.

Prior Art Conventionally, a supermodule in which a bundle of porous hollow fibers having micropores is enclosed in a cylinder is used to pass through an aqueous liquid (hereinafter abbreviated as water), and the water is passed through the micropores. Components in the water that cannot pass through the micropores are separated. In order for water to pass through the micropores, the hollow fibers must originally be hydrophilic, or if they are made of a hydrophobic material, the tube walls of the hollow fibers must be made hydrophilic. However, ordinary water to be treated often contains gases mainly composed of air (abbreviated as air), and when this reaches the hydrophilized pipe wall, it will not react at a normal pressure of about 1 kg/ ^cm2 , for example. They cannot pass through the tube wall and remain as bubbles on the tube wall of the hollow fiber, inhibiting the permeation of the water to be treated. Therefore, the overefficiency of the module decreases over time, and it may eventually reach a state where it is completely ineffective.

In order to improve this situation, it is considered that a part of the hollow fibers constituting the module is made hydrophobic so that the entrained air bubbles can penetrate into the hollow interior through the hydrophobic part and escape from the system through the open end. It is being In this way, in order to make only some fibers hydrophobic and other fibers hydrophilic, it is necessary to mix hydrophilic hollow fibers and hydrophobic hollow fibers in the desired ratio in advance and create a fiber bundle. A method of making modules is being considered. This method requires the preparation of both hollow fibers made of a hydrophilic material and hollow fibers made of a hydrophobic material, and has the disadvantage that the manufacturing cost is relatively high. Another drawback is that materials that are naturally hydrophilic are easily degraded by microorganisms.

Of course, it is also possible to make hydrophobic fibers hydrophilic through a hydrophilic treatment and to mix them with the original hydrophobic fibers in a desired ratio to form a fiber bundle, but it is also possible to make a fiber bundle by enclosing the fiber bundle in a module. When fixing the end of the fiber bundle to the housing with potting material, it must be done in a dry state, so the hydrophilic treatment in this case must be a permanent hydrophilic treatment that maintains its hydrophilicity even in the dry state. be. Hydrophilic monomer grafting, plasma treatment under special conditions, and the like are known methods for this, but these methods are cumbersome and increase the cost.

OBJECTS OF THE INVENTION The present invention has been made in order to overcome the drawbacks of the prior art, and it is an object of the present invention to provide a method for easily partially hydrophilizing a permodule made of hydrophobic hollow fibers.

Structure of the Invention The gist of the present invention is that a fiber bundle formed by bundling a large number of hydrophobic porous hollow fibers is housed in a cylinder, and at least one end of the fiber bundle has a hollow interior at one end of the cylinder. An open end is formed that communicates with the outside of the cylinder, but is filled and fixed with a potting material so that the spaces between the fibers and between the fibers and the inner wall of the cylinder are maintained watertight, and the opening end is filled and fixed with a potting material to maintain watertightness between the fibers and between the fibers and the inner wall of the cylinder. The liquid to be treated that is supplied into the cylinder is passed through only the porous pipe wall of the fibers and permeates into the hollow interior thereof, and the superhydrous water is discharged from the open end to the outside of the cylinder through the hollow interior. In the supermodule made,
Prior to use, an appropriate hydrophilic medium is press-fitted into the hollow interior of some of the hollow fibers constituting the fiber bundle through a part of the open end surface, or a hydrophilic medium is press-fitted into the hollow interior of the hollow fibers. After making the fiber bundle hydrophilic, a suitable hydrophobizing contact is press-fitted into the hollow interior of some of the hollow fibers through a part of the open end surface, thereby forming a supermodule having a hydrophilic part and a hydrophobic part. A method of processing a permodule using hollow fibers is provided.

In the present invention, any hydrophobic hollow fiber can be used as long as it is made of a hydrophobic material, including polyolefins such as polyethylene and polypropylene, and fluorinated fibers such as polytetrafluoroethylene and polyvinylidene fluoride. Examples include polyolefins.

The permutation module to which the present invention is applied includes both full permutation modules and partial permutation modules.

As the hydrophilic medium of the present invention, lower alcohols such as methyl alcohol, ethyl alcohol, and propyl alcohol, surfactant aqueous solutions, etc. can be used. Ethyl alcohol is preferably used from the viewpoint of ease of removal of the hydrophilic medium after substitution.

Although chemical substances such as fluorocarbons can be used as the hydrophobic medium, it is most convenient to use air.

EXAMPLES The present invention will be described in more detail below with reference to the drawings.

An example of the structure of the overuse module to which the present invention is applied is shown in FIGS. 1 and 2.

FIG. 1 shows a state in which a nozzle is pressed against a part of the open end face of the full-flow module in order to inject a hydrophilic medium or a hydrophobic medium. In this module, a plurality of fibers 1 having a hollow structure are bundled in parallel to form a fiber bundle, which is housed in a cylinder 3 in the axial direction, and one end of the fiber bundle is attached to a potting material 2 at one end of the cylinder. It is fixed to the inner wall of the cylinder. At this time, each fiber 1 is held so that its hollow interior is not blocked, that is, its hollow interior can communicate with the outside at the outlet 5, and the spaces between each fiber and between the fibers and the inner wall of the cylinder are completely watertight. It is necessary that the filling is fixed. The other end of the fiber bundle is a tube 3.
The other end is hermetically fixed to the cylinder 3.
Further, a water supply port 4 is provided in a part of the outer wall of the tube 3. FIG. 2 is a plan view of this module as seen from the exit side.

The pipe wall of the hollow fiber 1 has a large number of micropores, and the water to be treated injected into the cylinder 3 from the water supply port 4 penetrates into the hollow part of the hollow fiber 1 through the micropores, and at this time, the water to be treated penetrates into the hollow part of the hollow fiber 1. The purified water is filtered out of impurities and is discharged out of the system from the outlet 5 through the hollow section.

The one shown in FIG. 3 is another example of a supermodule, in which the hollow fiber bundle is housed in a tube 3 not in a straight line but in a U-shaped curve, and the hollow interior of both ends is connected to the outlet 5. It is fixed at one end of the tube 3 so as to be able to communicate with the outside. In this case as well, the spaces between the fibers and between the fibers and the inner wall of the cylinder are filled with the potting material 2 in a watertight manner. In this example, the water supply port 4 is provided at the lower end of the tube 3, and as in the previous example, the water supplied into the tube is passed through the porous tube wall of the fiber 1, and then exits from the outlet 5. Exhausted from the system.

In either case, as mentioned above, a part of the tube wall of the hollow fiber in the module, specifically about several percent of the total tube wall area, is hydrophobic, and the remaining portion is hydrophilic. Necessary to discharge air mixed in the treated water to the outside of the system.

In order to impart such a hydrophobicity ratio to the hollow fibers, in one embodiment of the present invention, a module is prepared using hydrophobic hollow fibers, and then a hydrophilic treatment is performed by a known method. When overwork is carried out in the normal manner using this, as mentioned above, the mixed air accumulates on the pipe wall, the overcapacity gradually decreases, and air bubbles grow one after another, causing air pockets 6 in the cylinder (Fig. 3). is accumulated and overefficiency decreases. In order to avoid this drawback, a nozzle 7 with a constant outlet cross-sectional area connected to a pressurized air supply source (not shown) is installed in the tube 3, either in advance or at the point where the air bubbles have accumulated during the course of filling the module with water. Pressurized air is supplied into the cylinder through the hollow part of the fiber by pressing against a certain area of the outlet end 5. The pressurized air passes through the tube wall of the hollow fiber in the region pushed up by the nozzle 7 from the inside to the outside and is discharged into the cylinder, at which time water in the tube wall of the hollow fiber is removed and replaced with water. Ru. As a characteristic of porous hollow fibers made of a hydrophobic material, once the air is encapsulated, it adheres to the walls of the micropores and is captured, making that part hydrophobic. Therefore, after this treatment, the air in the water can easily permeate into the hollow part of the fiber through the hydrophobized part, and the water permeation efficiency of other parts is prevented from being inhibited due to the accumulation of air bubbles. Ru.

According to the method of the present invention, the hydrophobization rate can be reliably controlled by changing the exit area of the nozzle 7 for supplying pressurized air, and by changing the area to which the nozzle 7 is pressed. The hollow fibers can be made hydrophobic at desired locations.

The above aspects will be further elucidated in the following examples.

Example 1 Hollow fiber made of polyethylene, outer diameter 0.38
mm, hole diameter 0.27 mm, a bundle of 960 pieces was bent into a U-shape with a length of 120 mm, an inner diameter of 25 mm,
The supermodule shown in FIG. 3 was prepared by housing the product in a polycarbonate cylinder having a thickness of 3 mm and a length of 150 mm, and fixing both together with a polyurethane resin potting material. 70% alcohol prior to use,
After pressurizing an alcohol solution containing 30% water into the module and then replacing it with water to make the fibers hydrophilic, two nozzles with a diameter of 2.0 mm are inserted into the open end of the fiber bundle at the outlet 5 of the module. pressure 4
Kg/cm ² and pressurized air at a temperature of about 23° C. was supplied for 3 minutes. As a result, the fibers with open ends in the area against which the nozzle was pressed were made hydrophobic.

Another embodiment of the present invention is to leave the originally hydrophobic fibers constituting the module as they are, and only the remaining fibers are made hydrophilic so as to have a predetermined affinity/phobicity ratio. That is, prior to use, a nozzle 7 having a constant outlet cross-sectional area is pressed against a part of the outlet end 5 of the cylinder 3, and alcohol is supplied from the nozzle 7. Alcohol is supplied into the cylinder through the hollow part of the fibers having openings in this region, passes through the pipe wall of the fibers, is discharged outside the upper hollow part filled with the fine pores, and is discharged to the outside of the system from the water supply port 4. Ru. Next, when water is injected from the nozzle 7, the alcohol remaining in the fiber tube wall is mixed with water and discharged, and the inside of the tube wall is replaced with water, thereby imparting hydrophilicity. This hydrophilic treatment is performed only on the fibers that have openings in the area where the nozzle 7 is applied, and the other fibers are left hydrophobic, so the exit area of the nozzle 7 is reduced as in the first embodiment. By changing the ratio, the affinity ratio can be reliably controlled, and only the hollow fibers at desired locations can be selectively made hydrophilic.

This second aspect will be further elucidated in the following examples.

Example 2 Hollow fiber made of polyethylene, outer diameter 0.38
25 mm in inner diameter, 3 mm in thickness, and 250 mm in length, 1,920 bundles of 1,920 bundles were placed in a polycarbonate tube with an inner diameter of 25 mm, a thickness of 3 mm, and a length of 250 mm, and both were placed in a potting material made of polyurethane resin. The supermodule shown in FIG. Prior to use, press four nozzles with an inner diameter of 8 mm against the open end of the fiber bundle at outlet 5 of the module.
After injecting 200 ml of an alcohol solution of 70% alcohol and 30% water, 500 ml of water was press-injected to replace the alcohol solution and make it hydrophilic.

The hydrophilic ratio was about 40%, which approximately matched the ratio of the nozzle exit cross-sectional area (π·8 ² /4×4 mm ² ) and the cylinder cross-sectional area (π·25 ² /4 mm ² ).

Effects of the Invention As detailed above, according to the present invention, by simply pressing the nozzle against a partial area of the open end of the module and pressurizing the hydrophilic medium or the hydrophobic medium, the desired ratio can be reliably obtained. It is possible to make the hollow fibers hydrophilic or hydrophobic at certain points, and it is far superior to conventional methods in terms of both quality and cost.

[Brief explanation of drawings]

FIG. 1 is a side sectional view of a module showing a first embodiment of the present invention. FIG. 2 is a plan sectional view taken along line A--A in FIG. 1. Figure 3 shows the second embodiment of the present invention.
FIG. 2 is a side sectional view of a module showing an embodiment. 1...Hollow fiber, 2...Potting material, 3...
...Cylinder 3, 4...Water supply port, 5...Outlet, 6...Air pocket, 7...Nozzle.

Claims (1)

[Scope of Claims] 1. A fiber bundle formed by bundling a large number of hydrophobic porous hollow fibers is housed in a cylinder, and at least one end of the fiber bundle is arranged such that the hollow interior thereof forms a cylinder at one end of the cylinder. An open end is formed that communicates with the outside of the cylinder, but is filled and fixed with a potting material so that the spaces between the fibers and between the fibers and the inner wall of the cylinder are maintained watertight, and the cylinder is inserted through a part of the cylinder. The liquid to be treated that is supplied into the tube permeates into the hollow interior through only the porous tube wall of the fiber, and the permeable water passes through the hollow interior and is discharged from the open end to the outside of the tube. In the above module, prior to use, an appropriate hydrophilic medium is press-fitted into the hollow interior of some of the hollow fibers constituting the fiber bundle through a partial region of the open end surface, or a hydrophilic medium is press-fitted into the hollow interior of some of the hollow fibers constituting the fiber bundle. After making the fiber bundle hydrophilic by press-fitting it inside, a suitable hydrophobizing medium is press-fitted into the hollow interior of some of the hollow fibers through a part of the open end surface, thereby separating the hydrophilic part and the hydrophobic part. 1. A method for processing permodule using hollow fibers, characterized by obtaining permodule having the following properties. 2. The processing method according to claim 1, wherein the ends of the fiber bundle other than the open end are watertightly sealed. 3. The processing method according to claim 1, wherein the fiber bundle is housed in a cylinder in a U-shape, and both ends of the fiber bundle form the open end. 4. Any one of claims 1 to 3, in which the fibers are first treated using an alcohol or a surfactant as a treatment medium, and then replaced with water to make a part of the hydrophobic module hydrophilic. The processing method described in paragraph 1. 5 Claim 1 in which a part of the module that has been made hydrophilic is made hydrophobic using air as a treatment medium
The processing method described in any one of Items 1 to 3.