JPS63143905A - Hollow yarn membrane filter - Google Patents

Abstract

PURPOSE:To prevent the damage of a hollow yarn and to perform effective backwashing, by a method wherein hollow yarns are arranged so that the length of each of the hollow yarns between both adhesive filling parts is so excessive as to satisfy a specific condition with respect to the interval between both adhesive filling parts. CONSTITUTION:In a hollow yarn membrane filter 2, the length L1 of each of the hollow yarns 2a arranged in a slightly loosened state between upper and lower end adhesive filling parts 6 is set so that an excessive length DELTAL satisfies the relation 0.01<=DELTAL/L1<=0.04 (wherein DELTAL=L1-L2) with respect to the distance L2 between both adhesive filling parts 6. By this method, the whirling-up of the hollow yarns 2a at the time of backwashing and the accompanying entanglement, bending or breakage can be prevented and, since the hollow yarns 2a are shaken properly, effective backwashing can be performed. Further, a solid component released at the time of backwashing is not accumulated in the hollow yarn membrane filter 2. Furthermore, a liquid effectively flows around the hollow yarns 2a positioned at a central part at the time of filtering.

Description

Detailed Description of the Invention [Objective of the Invention] (Industrial Application Field) The present invention is a hollow water treatment system used for the purpose of separating and removing solid parts in a liquid to be treated, in water treatment equipment of various plants. Regarding thread membrane filters.

(Prior Art) Generally, a hollow fiber is a hollow cylindrical fiber membrane having an outer diameter of 0.3 to 0.3 b and minute holes on its surface. It has the advantage of being able to provide a large filtration area within a unit volume and having excellent pressure resistance. Therefore, a filter is formed by bundling a large number of hollow fibers and hardening both ends with resin, which is an adhesive. This hollow fiber membrane filter is used as a filtration device for water treatment equipment.

Referring to FIG. 5 below, such a hollow fiber l! The configuration of the membrane filtration device will be explained. FIG. 5 is a sectional view of the hollow fiber membrane filtration device, and reference numeral 1 in the figure is the container body.

The inside of this container body 1 is divided into upper and lower halves by a partition plate 3, with the lower space serving as the filtration chamber 1a, and the upper space serving as the processing liquid chamber 1a.
b. A hollow fiber membrane filter 2- is suspended from the partition plate 3 in the filtration chamber 1a. The above-mentioned hollow fiber membrane filter L has a large number of hollow fibers 2a bundled around the outer periphery of a support 4, whose upper and lower ends are fixed with an adhesive filling part 6, and a collection fixing member 7 is further fixed from the outer periphery. It has a fixed and installed configuration. Further, at the position A shown in FIG. 1, two hollow fiber membrane filters 2- having the above structure are connected in the vertical direction, and reference numeral 8 in the figure is a connecting tube used in this case. A filtration chamber 1 is provided at the lower end of the container body 1.
A liquid supply pipe 10 communicating with the processing liquid chamber 1b is connected to the upper end thereof, and a processing liquid discharge pipe 11 communicating with the processing liquid chamber 1b is connected to the upper end. An on-off valve 12 is inserted into the liquid supply pipe 10, and a concentrated liquid discharge pipe 13 is branched and connected thereto. An on-off valve 14 is inserted into this concentrated liquid discharge pipe 13. The liquid supplied into the i11 passing chamber 1a through the liquid supply piping 10 is supplied to the hollow fiber membrane filter, ? - when passing through, it is filtered and discharged through the hollow portion of each hollow fiber 2a.

In the above configuration, by passing through a hollow fiber, a single filter,
When the differential pressure before and after 2- increases and reaches a specified value, a backwashing operation is performed to wash off solid matter adhering to the surface of each hollow fiber 2a. That is, pressurized gas for backwashing is supplied into each hollow fiber 2a of the hollow fiber membrane filter 2- through the treatment liquid discharge pipe 11. At the same time, perform bubbling operation from below the hollow fiber membrane filter L.
! ! vinegar. That is, a bubbling pipe 15 is disposed within the container body 1 below the hollow fiber membrane filter 72-, and a bubble hole 16 is formed in the lower surface of the bubbling pipe 15. In addition, the bubbling pipe 15 has an on-off valve 18
It is connected to an air supply pipe 17 having a.

Then, the air supply pipe 17 is connected to the bubbling pipe 15.
Air bubbles are generated from the air bubble holes 16 by supplying air through the air bubbles. Hollow fiber membrane filter, due to the air bubbles? −
Bubble to enhance the cleaning effect. In addition, the partition 1f
One overflow pipe is connected to the container body 1 located below i3, and an on-off valve 20 is inserted into the overflow pipe 19. Further, reference numeral 21 in the figure is a protection tube, and this protection tube 21 effectively introduces air bubbles from the above-mentioned bubbling into the hollow fiber membrane filter L.

By the way, when performing backwashing on the hollow fiber membrane filter 2- having the above-described structure, with respect to the distance between both ends (indicated by the symbol L2 in FIG. 5) determined by the adhesive filling portions 6 at both ends, How much extra length should be determined for the length of the hollow fibers 2a arranged between them (the length of the hollow fibers 2a is slightly slack between the intervals 1 and 2 as described above, so it is larger than L2) to ensure that the bubbling described above is effective. At present, it has not been determined whether this can be done and damage to the hollow fibers 2a can be prevented. Conventionally, it was set with an extra length of about 5Z. However, as filtration and backwashing were repeated, multiple hollow fibers 2a
A situation occurred in which the parts became tangled, bent, and damaged.

This means that the hollow fibers 2a are made of a polymeric material. ! ! ! It is thought that the hollow fibers 2a were thrown up and bent/damaged because their relative widths were almost equal to water, which is the main component of the treatment liquid. As a means to solve such problems, the above-mentioned 5X
It is conceivable to shorten or eliminate the extra length set to a certain degree. However, when such a method is adopted, the following problems occur.

(1) First, the swinging width of the hollow fibers 2a when performing the bubbling described above is restricted more than necessary, making it impossible to obtain a sufficient bubbling effect.

■Hollow fiber membrane filter, 2- as mentioned above? ! Several hollow fibers 2a are bundled in a dense arrangement,
If the extra length is reduced, the liquid to be treated will not effectively flow between the hollow fibers 28, resulting in only the hollow fibers 2a located on the outer periphery of the hollow fiber membrane filter 2- being subjected to filtration.

This is not preferable from the point of view of filtration efficiency, and also causes a phenomenon in which solid matter adheres only to the hollow fibers 2a located on the outer periphery.

(2) Furthermore, when backwashing is performed, there is a problem in that the solids exfoliated by the backwashing accumulate between the hollow fibers 2a, and the exfoliated solids are not efficiently discharged. This is also due to the fact that the hollow fibers 2a are densely arranged and the remaining length is small, resulting in poor flowability between the hollow fibers 2a, as in the above case.

(Problems to be Solved by the Invention) As described above, sufficient consideration has not been given to how to determine the extra length of conventional hollow fiber membrane filters, and as a result, various problems have arisen. The present invention has been made based on the following points, and its purpose is to provide a hollow fiber having an extra length that prevents breakage of the hollow fiber and enables effective backwashing. The purpose of the present invention is to provide a membrane filter.

[Structure of the Invention] (Means for Solving the Problems) That is, the hollow membrane filter according to the present invention collects a plurality of hollow fibers and fills them with a filler so that both bundled ends thereof are open. In the hollow fiber membrane filter in which the adhesive-filled portions at both ends are connected by a predetermined length by installing and fixing a focusing fixing member around the outer periphery of the adhesive-filled portion filled with the adhesive, the indirect The length L1) of the hollow fiber between the adhesive filled parts is arranged with a predetermined extra length (ΔL) with respect to the distance (L1) between the adhesive filled parts, and this extra length (ΔL)
) is characterized by satisfying the following conditions.

0.01≦(ΔL/Ls)≦0.04, where Ll Length Ll of the hollow fiber arranged between the two adhesive-filled parts; Distance ΔL between both adhesive-filled parts; (Ll-12) ( Effect) By keeping the extra length of the hollow fibers within the above range, it is possible to eliminate the entanglement of the hollow fibers that occurs due to the extra length, as well as the bending and breakage caused by this, as well as the backwashing that occurs when the extra length is too small. This effectively solves problems such as decreased effectiveness.

(Embodiment) An embodiment of the present invention will be described below with reference to FIGS. 1 to 4. It should be noted that the same parts as in the prior art are denoted by the same reference numerals and the explanation thereof will be omitted. FIG. 1 is a cross-sectional view showing the structure of the hollow fiber membrane filter 2-.
L1) is the distance lI! between each of the adhesive filling portions 6! 1 (12
) has a surplus length of (△L), and this surplus length (
ΔL) is set within the following range. 0.01≦(
ΔL,'1-1)≦0.04...(I>However, Ll; Length 2 of hollow fiber arranged between both adhesive-filled parts; Between both adhesive-filled parts The interval ΔL; (L+ -12>) The reason why the extra length (8L) is set within this range is to effectively eliminate both the negative effects of having too large a surplus length and the negative effects of having a surplus length that is too small. This will be explained below with reference to FIGS. 3 and 4.

In Figure 3, the horizontal axis is the length of the hollow fiber 2a (L1) with extra length (Δ).
), and the vertical axis represents the number of bent portions of the hollow fibers 2a (per 1000 hollow fibers). According to this, it can be seen that when the ratio of the extra length (ΔL) to the length L1) of the hollow fibers 2a is 4 or less, the number of hollow fibers 2a in which bent portions have occurred is extremely small. Therefore, if the excess length (ΔL) ratio is set to 4 or less, the adverse effects caused by the large excess length can be effectively eliminated.On the other hand, the lower limit value will be explained with reference to FIG.

Figure 4 shows a length comb 1 of the hollow fiber 2a with extra length (ΔL) on the horizontal axis.
), and the vertical axis is the backwashing efficiency (solids removed by backwashing/captured solids, %).As is clear from Figure 4, Extra length (
It can be seen that when the ratio of the hollow fibers 2a (ΔL) to the length L1) becomes 1 or less, the backwashing efficiency deteriorates rapidly.

This is because, as shown in Fig. 2, when bubbling is performed during backwashing, the hollow fibers 2a need to swing to some extent.
This is because the solid content is washed away by the shaking. Furthermore, the following was observed. In other words, when the ratio of the surplus length (ΔL) is less than 1, the movement of the hollow fibers 2a is restricted more than necessary, so that the filtrate is Not distributed,
As a result, only the hollow fibers 2a at the outer periphery are subjected to filtration.

This can be observed from the fact that the solid content adheres only to the hollow fibers 2a located on the outer periphery. At the same time, it was also confirmed that when the ratio was less than 1, solids separated during backwashing accumulated on the hollow fiber membrane filter and could not be removed effectively. For this reason, the lower limit of the ratio of the extra length (ΔL) to the length L1) of the hollow fiber 2a is set to 1.

According to this embodiment, the following effects can be achieved.

(1) First, it is possible to effectively prevent the hollow fibers 2a from flying up during backwashing and thereby becoming entangled, bent or damaged.

(2) Next, during backwashing, the hollow fibers 2a are swayed appropriately, making it possible to perform effective backwashing.

・■Also, the solid content peeled off during backwashing is transferred to the hollow fiber membrane filter 2.
It doesn't get stuck inside.

■A hollow fiber membrane filter even during filtration? - Since the filtrate effectively flows around the hollow fibers 2a located in the center of the area, it is possible to prevent a situation where filtration is performed only at the outer periphery, and it is possible to provide efficient filtration. .

[Effects of the Invention] As detailed above, according to the hollow fiber membrane filter of the present invention, it is possible to prevent hollow fibers from flying up, entanglement, and even bending and breakage, as well as to effectively prevent Its effects are great, such as being able to provide cleansing.

[Brief explanation of the drawing]

Figures 1 to 4 are diagrams showing one embodiment of the present invention.
The figure is a front view of a hollow fiber membrane filter, Figure 2 is a front view of a hollow fiber membrane filter showing the action during backwashing, and Figure 3 is a change in the number of bent portions when the extra length of the hollow fibers is changed. Characteristic diagram showing Figure 4 is hollow fiber filter, 2-... hollow fiber filter, 2a
... hollow fiber, 4 ... support body, 6 ... adhesive filling part, 7 ... focusing fixing member. Figure 1 Figure 2 1&ΔL/) Hollow spear, long LzC'iV? v Rei ('10
) Pi9) Hollow 1 of Socho ΔL (4 harm wealth noted in L2)
11/. (Δ1n)

Claims (1)

[Claims] A plurality of hollow fibers are bundled and fixed by being filled with an adhesive so that both bundled ends are open, and a bundle fixing member is provided on the outer periphery of the adhesive-filled part filled with the adhesive. In a hollow fiber membrane filter in which the adhesive-filled parts at both ends are connected with a predetermined length by installing and fixing, the length (L_1) of the hollow fiber between the two adhesive-filled parts is equal to the length (L_1) of the hollow fiber between the two adhesive-filled parts. The interval between (L_
2) A hollow fiber membrane filter, characterized in that it is arranged with a predetermined extra length (ΔL) relative to 2), and this extra length (ΔL) satisfies the following conditions. 0.01≦(ΔL/L_1)≦0.04 However, L_1; Length of hollow fiber arranged between both adhesive-filled parts L_2; Distance ΔL between both adhesive-filled parts; (L_1-L_2)