JPH02241523A - Hollow yarn membrane module - Google Patents

Abstract

PURPOSE:To prevent cutting troubles of hollow yarns and extend their service life by fixing protective yarns having similar properties to the hollow yarns with a cured layer around the outsides of upper and lower end parts of a plurality of hollow yarns and surrounding each end part of the hollow yarns with the protective yarns. CONSTITUTION:Each upper and lower end parts of a plurality of hollow yarns 1 are fixed with adhesive cured layers 3, 5 and the hollow yarns are gathered while each yarn being kept in a distance. A protective yarn 7 having similar properties to the hollow yarns is fixed with the cured layer around at least the outside of the upper part of each upper and lower end parts of a plurality of the hollow yarns 1 so as to surround at least the upper part of each upper and lower part of the hollow yarns 1 with the protective yarn 7. As a result, cutting troubles of the hollow yarns are prevented and service life of the hollow yarns are extended.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a hollow fiber membrane module whose peripheral wall is composed of a plurality of hollow fibers made of permeable membranes.

(Prior Art) A hollow fiber membrane module is known in which the upper and lower ends of a large number of hollow fibers are fixed with a hardened layer of adhesive at a distance from each other and bundled together.

The hollow fibers of each of these hollow fiber membrane modules trap impurities such as iron oxides and hydroxides in the raw water on the membrane surface by the water pressure that the raw water applies to the outer periphery of the permeable membrane. The permeated treated water is collected in the hollow part. When the amount of impurities captured on the membrane surface increases, air or treated water is injected into the hollow part and backwashed to remove the impurities, or air bubbles are brought into contact with the outer peripheral surface, which is the capture surface, and the air flow Impurities are peeled off using the shearing force of the material, recycled, and used repeatedly.

The upper and lower ends of this hollow fiber are inserted into a cylindrical frame made of Noryl resin, polysulfone resin, etc., and a hardened layer of epoxy resin adhesive filled inside the cylindrical frame is used to create a tube. Either it is combined with a frame or the like, or it is shaped like a cylinder with the frame removed after the adhesive has hardened.

<Problems to be Solved by the Invention> When an adhesive such as an epoxy resin is filled into a cylindrical frame, the permeable membranes at the upper and lower ends of the cylindrical frame become watery. The adhesive penetrates by capillary action, and at the upper end, it is 10 to 30 m++ from the bottom surface of the hardened layer inside the cylindrical frame.
from the upper surface of the hardened layer in the cylindrical frame to the lower end.
The area up to about 30a+m is the cured part containing the cured adhesive.

On the other hand, during filtration to obtain treated water in the hollow part, pressure is applied from the outer periphery of the hollow fiber monohydric permeable membrane, and conversely, pressure is applied from the inner periphery during backwashing.

The upper and lower hardened parts are reinforced by the hardened adhesive in response to the pressure applied from the outer periphery and the inner periphery, and the degree of contraction and expansion is small, but the part that does not contain adhesive between the upper and lower hardened parts is large. The hollow fiber contracts and expands, causing the hollow fiber to vibrate around the boundary between the upper and lower hardened portions and the portion that does not contain adhesive between them, causing fatigue at this boundary and causing the hollow fiber to break.

In addition, when removing impurities trapped on the outer surface with air bubbles, the shearing force of the air flow causes the hollow fibers to sway, but the fulcrum of this swaying is the upper and lower hardened parts, and does not include the adhesive between them. Since it becomes the boundary between the parts, the boundary also gets fatigued and the hollow fiber is cut from this point. This tendency is particularly noticeable in the hollow fibers located in the outer layer of a bundle of multiple hollow fibers and in the upper end of the module where the hollow fibers vibrate during cleaning by blowing air into the module.

<Means for Solving the Problems> Therefore, the present invention provides a hollow fiber membrane module in which the upper and lower ends of a large number of hollow fibers are fixed with a hardened layer of adhesive while maintaining a water-dead interval, and are bundled together. Protective fibers having physical properties similar to those of the hollow fibers are fixed with the hardening layer around at least the outside of the upper and lower ends of each of the upper and lower ends of the plurality of hollow fibers. It is characterized in that the outside is surrounded by the above-mentioned protective thread.

<Examples> In each of the illustrated examples, 1 is a hollow fiber constituting a bundle, and 2 is an epoxy resin filled inside the upper end portions of a large number of the hollow fibers, with a water-dead interval maintained. A cylindrical frame made of noryl resin, polysulfone resin, etc. is fixed with a hardened layer 3 of adhesive such as a resin type, and 4 is a cylindrical frame made of a bundled noryl resin or polysulfone resin. Noryl resin fixed and focused with a cured layer 5 of filled adhesive such as epoxy resin,
Shows a cylindrical frame made of polysulfone resin or the like.

The hollow fibers are made of PVA, polysulfone, polyethersulfone, polyolefin, polypropylene, polyethylene, etc., and the filtration area is approximately 1.6 mm in outer diameter, approximately III m in inner diameter, and 1 mm in length. 0.00
5 m". Therefore, approximately 1,200 hollow fibers with a length of 1.5 m are bundled in the upper and lower cylindrical frames 2.4 of the inner diameter 1 G (lam), and the filtration area of one mosier is The upper end of the hollow part of the hollow fiber is opened on the upper surface of the hardened layer 3, so that the treated water that permeates through the hollow part is collected, and the lower end is opened in the hardened layer 5. In addition, the hardened layer 5 converging the lower ends of the hollow fibers is provided with ventilation holes 6 located at intervals between the hollow fibers and penetrating in the vertical direction, so that impurities captured by the hollow fibers on the membrane surface are It is designed to supply air that separates the particles using shear force.

Now, 7 indicates a protective thread which is fixed around the outside of each of the upper and lower ends of a large number of hollow fibers with a hardening layer 3.5, and surrounds the outside of each of the upper and lower ends of the hollow fiber, according to the present invention. The protective fiber 7 having similar physical properties to the hollow fiber 1 means that it may be made of the same material, or may be made of a different or similar polymeric substance. The protective thread may be hollow like a hollow fiber, or may be solid instead of hollow.

Furthermore, the protective threads are provided outside each of the upper and lower ends of the bundle of hollow fibers, in an internally and externally dispersed manner, in approximately 2 to 6 layers.

In any case, filtration is performed only by the hollow fiber l...
Even if the protective thread 7 is hollow, it does not participate in filtration.

In the embodiment shown in Fig. 1, the hollow fibers are fixed together with 10 bundles of hollow fibers by hardened adhesive layers 3 and 5 filled in the upper and lower cylindrical frames 2 and 4. The downward length of the protective thread from the bottom surface of the upper hardened layer 5 and the upward length of the protective thread from the top surface of the lower hardened layer 5, showing the case where the outside of each upper and lower end of the bundle 1 is surrounded. is 2 to 4 times longer than the level of the boundary I' between the cured part of the hollow fiber containing the cured adhesive and the other part not containing the adhesive.

If the protective thread 1 is solid, it does not inherently have a filtration function, so when used as the upper protective thread, even if the upper end is exposed on the upper surface of the hardened layer 3, it is buried in the hardened layer 3. Alternatively, when used as a lower protective thread, its lower end may also be exposed on the lower surface of the hardened layer 5 or buried in the hardened layer 5.

However, if the protective thread 7 is hollow like the hollow fiber 1, the upper end of the upper protective thread is buried in the hardened layer 3 to lose its filtration function, and the lower end of the lower protective thread is also preferably hardened. Embedded in layer S.

In this way, by surrounding the upper and lower ends of the bundle of hollow fibers 1 several times inside and outside with protective threads 7 that are longer than the boundary l' and protrude downward and upward from the hardened layers 3 and 5, The hollow fibers in the outer layer of the bundle are prevented from vibrating or swinging around the boundary 1゛ as a fulcrum, which reduces fatigue at the boundary and prevents the hollow fibers from being cut from there.Using a hollow fiber membrane module Lifespan can be extended.

In addition, in the figure, 8 indicates a protection tube.

FIG. 2 shows an embodiment in which the length of the protective thread 7 is the same as that of the hollow fiber 1, and each of the protective threads for water damage is fixed at the top and bottom with hardened M3 and M5 like the hollow fiber 1. If the protective thread 7 is hollow, it is preferable that the upper end is buried in the hardened layer 3 to lose its filtration function, and the lower end is also buried in the hardened layer 5. Of course, the protective thread has a filtration function. If it is a solid yarn that does not contain any solid fibers, the upper and lower ends may be buried in the hardened layer 3.5, or they may be exposed on the upper surface of the hardened layer 3 or the lower surface of the hardened layer 5.

In this way, by surrounding the outside of a bundle of hollow fibers several times inside and outside with protective fibers of the same length as the hollow fibers, the hollow fibers in the outer layer of the bundle can be prevented from vibrating or swaying around the boundary 1゜ as a fulcrum. It can be prevented more effectively.

<Effects of the Invention> The present invention can prevent hollow fiber cutting accidents and provide a hollow fiber membrane module with a long service life.

[Brief explanation of drawings]

FIG. 1 is an enlarged cross-sectional view of a main part of an embodiment of a hollow fiber membrane module according to the present invention, and FIG. 2 is a cross-sectional view of another embodiment of a hollow fiber membrane module according to the present invention. . In the figure, 1 is a hollow fiber and its boundary, 2 and 4 are cylindrical frames, 3 and 5 are cured layers of adhesive, 6 is a ventilation hole, and 7 is a protective thread.

Claims (1)

[Scope of Claims] In a hollow fiber membrane module in which the upper and lower ends of a large number of hollow fibers are fixed with a cured layer of adhesive with a distance between each fiber, the upper and lower ends of the above-mentioned large number of hollow fibers are Protective fibers having physical properties similar to those of the hollow fibers were fixed with the hardening layer around at least the outside of the upper end of each end, and at least the outside of the upper end of each of the upper and lower ends of the hollow fiber was surrounded by the protective thread. A hollow fiber membrane module characterized by: