JPH0346833Y2 - - Google Patents

Description

[Detailed explanation of the idea]

(Field of Industrial Application) The present invention relates to a hollow fiber type over-element which is reinforced near the end where it is bonded to a resin. (Prior art) In recent years, a hollow fiber type over-element in which a large number (usually 100 or more) hollow fibers having a microporous structure with one end sealed and the other end open is bundled and fixed by adhesive is housed in a container. By flowing the treatment liquid through the outside of the hollow fiber, various waste liquid treatments or pretreatments for recovering useful components such as sugar solution are performed. When hollow fibers are used in the above fields, they not only have high pressure resistance and durability, but also chemical resistance such as acid and alkali resistance and heat resistance for cleaning to restore the performance of clogged membranes. sexuality is required. For this purpose, not only the hollow fibers but also the resin that adhesively fixes the hollow fiber bundles must have a high degree of pressure resistance and durability, and are usually relatively hard with a Rockwell hardness of 60 or higher at room temperature. Resin is used.
However, when a hollow fiber bundle is bundled and fixed using the above-mentioned resin with high hardness, many of the hollow fibers at the bonded ends, mainly in the area near the outer edge, become hollow due to aging or backwashing with gas or liquid. There were many accidents in which the bonded ends broke due to swinging of the thread.
In order to prevent breakage at the adhesive end of the hollow fiber,
The present applicant has developed a hollow fiber type over-element in which the outer edge of the bonded end of a hollow fiber bundle is surrounded by an elastic band.
Proposed in No. 99073. The hollow fiber type over-element described above was extremely effective in preventing breakage of the hollow fibers mainly at the outer edge due to bending moments. (Problems to be Solved by the Invention) However, when the above-mentioned over-element was used, although leakage due to breakage of the hollow fibers was eliminated, leakage of unknown cause still occurred. When this leak of unknown cause occurs, the above-mentioned over-element must be replaced or the end opening of the hollow fiber where the leak has occurred must be sealed and reused, but it is applicable to the treatment of liquids with relatively high SS components. In this case, leaks of unknown cause frequently occurred, which was extremely problematic in practical terms. The inventors of the present invention assumed that the above-mentioned leak of unknown cause was due to external factors, and as a result of thoroughly observing each hollow fiber in which the leak had occurred, they found that all of the hollow fibers were connected to the adhesive end with the resin. It was found that extremely small cracks occurred in the circumferential direction of the hollow fibers near the outer periphery of the hollow fiber type super-element, and moreover, they were found to occur more often in the hollow fibers in the part slightly inside the hollow fibers at the outer periphery of the hollow fiber type super-element. . It is presumed that the above-mentioned cracks were caused by SS components accumulated on the surface of the hollow fibers over time and pushed into the bonded parts of the hollow fibers. (Means for Solving the Problems) In order to prevent cracks in the hollow fibers near the bonded ends, the inventors of the present invention further investigated and found that the hollow fibers near the bonded ends surrounded by a flexible band were The present invention was developed based on the discovery that cracks can be reliably prevented by improving the bending strength of the steel. That is, the present invention is a hollow fiber type over-element in which the open ends of a large number of hollow fibers having a micropore structure, one end of which is closed and the other end of which is open, are bundled and the bundled ends are adhesively fixed with resin. Then, the adhesive end of the hollow fiber bundle adhesively fixed with the resin is surrounded by a flexible band-like body, and the micropores of each hollow fiber near the adhesive end surrounded by the flexible band-like body are has at least bending strength within
This is a hollow fiber type over-element that is characterized by being impregnated with resin to a 1.3 times the amount. (Example) Next, an example of the hollow fiber type over-element of the present invention will be described with reference to the drawings. Figure 1 shows a hollow fiber type over-element 10.
This element includes a large number of hollow fibers 1 with one end sealed and the other end open, a resin 2 with the open ends of the hollow fibers converged and adhesively fixed, and a resin 2 near the adhesive end A. The resin is impregnated into the many micropores provided in the wall membrane of the hollow fiber. The bending strength of hollow fibers impregnated with this resin is usually improved by 1.3 times or more, but if the surface of the hollow fibers impregnated with the resin is thinly coated with resin 3 to the extent that the hollow fibers do not adhere to each other, the bending strength can be further improved. be able to. One end of the hollow fiber 1 is liquid-tightly sealed with a closure member 4 made of epoxy resin, polyurethane resin, etc., and the other end is open for introduction or extraction of liquid. Examples of materials for this hollow fiber include polyvinyl alcohol, polyacrylonitrile,
Synthetic polymers such as polysulfone, polyamide, and polyvinyl chloride; natural or recycled polymers such as cellulose acetate and cellulose; inorganic materials such as glass and ceramic; and carbon. The hollow fibers usually used have an outer diameter of 50 to 5000μ and an inner diameter of 20 to 2000μ. The number of hollow fibers per bundle completely depends on the diameter of the hollow fibers, and is rather limited by the bundle diameter of the hollow fibers (the bundle diameter when only the hollow fibers are made into a round bundle), and is usually 0.5 to 20 cm. The hollow fibers used in the present invention have a homogeneous micropore structure, and hollow fibers having such a structure are described, for example, in Japanese Patent Application Laid-Open No. 117380/1983. The resin 2 for bundling the hollow fibers and adhesively fixing their open ends is an adhesive having a relatively high hardness, that is, an adhesive having a Rockwell hardness (M scale) of 60 or more at room temperature. These resins include, for example, plastics such as epoxy resins, unsaturated epoxy resins, unsaturated polyester resins, phenol resins, urea resins, and polyurethanes, and plastics in which inorganic substances such as talc, titanium, and silica are added as fillers to these plastics, and These include composites in which fibers such as glass and vinylon are dispersed. The adhesive mentioned above is used when the hollow fiber and the housing are integrally molded, or in the case of a cartridge type bundle where the hollow fiber and sheath (a jig attached to the handle to fasten the handle to the housing) are filled with adhesive and bonded. Adhesives with little curing shrinkage are preferred, and for example, epoxy resins, polyurethane, vinyl ester resins, etc. alone, inorganic fillers, fibers, or composites of these in combination are useful. Near the bonded end of the hollow fiber with the resin 2, in order to prevent cracks in the hollow fiber, resin is impregnated into the micropores provided in the membrane wall of the hollow fiber, and a thin coating layer 3 is formed on the surface of the hollow fiber. to reinforce the hollow fibers. As this resin, a resin having excellent heat resistance and chemical resistance, such as epoxy resin or polysulfone resin, is used like the resin for adhesively fixing the hollow fiber bundle. This covering layer 3 may be made of the same resin as the resin that adhesively fixes the hollow fiber bundle, or may be made of a different resin. In addition, the coating layer 3 needs to cover the area where cracks occur in the hollow fiber, for example, an area of at least 2 mm from the bonded end A of the hollow fiber, but if it covers too wide an area, the effective membrane area will decrease. Undesirable. For this reason, the surface of the hollow fiber within a range of 1 to 20 cm from the bonded end A is usually covered, but in practice it is possible to cover the vicinity of the bonded end of the hollow fiber type over-element proposed in Utility Model Application Publication No. 55-99073. It is preferred to cover an area larger than the flexible band (usually 2-5 cm). The coating layer 3 is effective in preventing cracks in the hollow fibers so that the micropores provided in the membrane walls of the hollow fibers are sufficiently impregnated with resin. Further, the thickness of the resin layer coated on the surface may be such that adjacent hollow fibers are not bonded to each other. To impregnate and coat the hollow fibers with resin, before adhesively fixing the hollow fiber bundle, the resin is applied directly to a predetermined area of the hollow fibers, or it is diluted with a solvent and then applied and cured, or centrifugal adhesive is used. When adhesively fixing the ends of the hollow fiber bundle using a machine, the position of the resin tank, which stores the resin to be supplied to the hollow fiber ends and is located on the same circumference as the adhesive end A of the bundle, is set at a predetermined position. After forming a thin resin layer on the entire surface of the end of the hollow fiber in advance, move this tank to the same circumference as the adhesive end A and fix the end of the hollow fiber with adhesive. You can. FIG. 2 shows an example of a liquid treatment device using the hollow fiber type over-element 10, in which a gas inlet 1 is provided at the top.
2. Stock solution inlet 13 and concentrated solution outlet 18 at the bottom
The hollow fiber bundle 10 is liquid-tightly attached to a partition plate 14 having a plurality of openings for accommodating the hollow fiber bundle, which is provided at the upper end of a cylindrical container 11 having a cylindrical container 11. Additionally, a lid 16 having a liquid outlet 15 is provided at the top of the container 11.
is attached. The hollow fiber bundle 10 housed in the container is provided with a flexible band 17 made of rubber or woven fabric to protect the hollow fibers at the outer edge of the hollow fiber bundle near the bonded end. The hollow fibers are impregnated with resin, and a coating layer 3 is formed on the hollow fibers. In the above-mentioned apparatus, a predetermined amount of stock solution is introduced under pressure into the container from the stock solution inlet 13 during the over-step process, and the liquid that has passed through the hollow fibers is discharged from the liquid outlet 15 provided in the lid 16. The concentrated stock solution is discharged from a discharge port 18 provided at the bottom of the container and supplied to the next process. On the other hand, once the passing step is completed, a chemical solution is introduced into the container and chemical washing is performed. After this chemical washing is completed, the above operation is performed. Example 1 The PVA hollow fiber having a microporous structure manufactured in Example 1 of JP-A-54-117380 was cut into a length of 1 m, and after bundling 3000 hollow fibers, one end of the hollow fiber was The sample was immersed for 20 minutes in a liquid mixture consisting of 300 parts of Epiclon 850 (manufactured by Dainippon Ink), 100 parts of 2-ethyl, and 5 g of 4-methylimidazole, and then thoroughly drained. Next, the hollow fibers were air-dried, being careful not to adhere to each other, and then heated at 90° C. for 3 hours to impregnate and coat the hollow fibers with resin. As shown in Utility Model Application Publication No. 55-99073, the outer periphery of the thus reinforced hollow fiber type over-element was covered with a flexible band, and then adhesively fixed with epoxy resin.
Table 1 shows the results of comparing the strength of this element with the strength of an element not impregnated with resin or coated.

[Table] Example 2 A 1 m long hollow fiber was installed in the liquid treatment device shown in Figure 2.
The device was equipped with 55 hollow fiber type over-elements with 3000 bundled together.
As elements to be installed in the above device, 30 elements were impregnated with resin and coated with the resin produced in Example 1, and 30 elements were impregnated with resin and were not coated.
It accommodated 25 bottles. With this equipment, at 40°Bx and 60°C, the SS component content (ratio of the height of SS sediment after heating the raw material and standing for 24 hours) is 16% Susomono sugar solution (mother liquor obtained by crystallizing sugar components). The durability of the hollow fiber bundles was tested by continuously treating the fibers (Group) for 90 days using a chemical-washing sequence. Passing process [(sugar solution passing 90 minutes +
Concentrate discharge) + (hot water filling + air washing discharge) × 3] ×
3 Chemical washing process (2%, 60℃ aromatic soda immersion for 90 minutes + cold water washing + 0.5% RT hydrochloric acid immersion for 5 minutes + cold water washing) (However, the air amount is 400Nl/hr.m ² (per membrane area).
(performed in minutes). Table 2 shows the leak status of the element when the lid was opened for inspection. However, if a leak occurred, we repaired it at that point and restarted it with no leak.

[Table] (Effects of the invention) As described above, the present invention impregnates the fine pores of the hollow fibers near the ends where they are bonded with the resin, and coats the surface with a thin resin layer. Or, the rocking or vibration of the hollow fiber during backwashing with gas or liquid and the concentration on the surface of the hollow fiber.
This is extremely useful in practice as it can completely prevent cracks in the hollow fibers due to the phenomenon of the SS component interfering with the hollow fiber bonding area.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a hollow fiber type over-element of the present invention, and FIG. 2 is a sectional view of a liquid treatment apparatus using the above-mentioned element. 1...Hollow fiber, 2...Resin, 3...Coating layer, A
...Adhesive end.

Claims (1)

[Scope of utility model registration request] It is a hollow fiber type over-element in which the open ends of a large number of hollow fibers having a micropore structure, one end of which is closed and the other end of which is open, are bundled and the bundled ends are adhesively fixed with a resin. Surrounding the adhesive end of the adhesively fixed hollow fiber bundle with a flexible band-like body, and at least bending it into the micropore of each hollow fiber near the adhesive end surrounded by the flexible band-like body. A hollow fiber type superelement characterized by being impregnated with resin so that its strength is 1.3 times higher.