JPH05285354A - Washing and regenerating method for filter membrane - Google Patents

Abstract

PURPOSE:To effectively remove solid material stuck on the membrane surfaced of a ceramic filter by combining a gaseous washing fluid with a liquid washing fluid and acting the combined washing fluid on the solid material stuck on the membrane surface of the ceramic filter. CONSTITUTION:A stop valve 7 is opened and both of high-pressure gas for washing and washing liquid are sent and allowed to act on solid material S stuck on the membrane surface 1a of a ceramic filter 1. In other words, the stuck solid material is peeled by the high-pressure gas and thereafter washed down by the liquid washing fluid. Therefore even the solid material is completely removed which is clogged on the membrane surface of a filter medium such as the ceramic filter and strongly stuck thereon.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for cleaning and regenerating a filtration membrane in a filtration device using an ultrafiltration membrane.

[0002]

2. Description of the Related Art Various methods for cleaning and regenerating an ultrafiltration membrane of this type have been proposed. JP-A-3-188928
In No. 6, the filtration membrane is vibrated to remove the deposits. In Japanese Patent Publication No. 55-37283, gas and liquid are made to flow on the surface of the film.

[0003]

However, in the above-mentioned prior art, since the membrane is vibrated or the cleaning liquid or gas flows on the surface of the membrane, even solid matter clogged in the fine through-holes of the membrane can be obtained. Is also difficult to remove. Therefore,
As it ages, its filtration efficiency decreases, and if it reaches the limit, it must be decomposed and regenerated or replaced.

[0004]

The present invention has solved the above-mentioned problems, and its gist is to provide a cleaning liquid and a cleaning gas to a solid matter attached to a film surface. As a specific method of causing the cleaning liquid and the cleaning gas to act on the solid matter, for example,
After blowing the film with the solid matter on it from the back side with high-pressure gas, the cleaning solution may be sent from the back side to backwash it. Alternatively, the cleaning solution may be poured onto the surface of the film with the solid matter on the back side. The high-pressure gas may be blown from the side, the back-washing may be performed with the cleaning liquid in accordance with the high-pressure gas to be blown, and the high-pressure gas may be also flowed in the cleaning liquid flowing on the membrane surface. Alternatively, the cleaning gas may be dissolved in the cleaning liquid under high pressure without separately supplying the cleaning liquid and the high-pressure gas, and the cleaning gas may be liberated and vaporized on the membrane surface to act on the solid matter. Furthermore, the stock solution on the film surface may be vacuumed to float the solid matter, and then a high-pressure cleaning gas may be blown from the back surface side of the film.

[0005]

As described above, according to the present invention, the cleaning liquid and the cleaning gas are used together to remove the solid matter generated on the film. Therefore, the cleaning gas first gives an impact to the solid matter on the film to remove it. In addition, the peeled solid matter is washed away, and therefore, even the solid matter clogged can be removed. For example, when backwashing with a cleaning gas and a cleaning liquid, the solid matter can be floated by the cleaning gas and then washed away with the cleaning liquid.When a cleaning liquid in which the cleaning gas is supersaturated is used, the cleaning liquid is When the cleaning gas is released from the solution by contacting with the solid matter, the cleaning gas acts on the solid matter and is separated from the filtration membrane, and at the same time, it can be washed away by the cleaning solution. Hereinafter, the present invention will be described more specifically with reference to the drawings.

[0006]

1 to 5 show an outline flow of a method for cleaning and regenerating a filtration membrane according to the present invention, in which reference numeral 1 is a ceramic filter, 2 is a storage container for the ceramic filter, 3 is a feed pump for the undiluted solution,
4 is an opening / closing valve provided in the stock solution supply passage, 5 is an opening / closing valve provided in the filtrate outlet passage, 6 is an opening / closing valve provided in the wash water discharge passage, 7 is an opening / closing valve provided in the cleaning fluid supply passage, 8 Is an on-off valve provided in the air supply path into the stock solution, and 9 is a filtrate receiving tank. Although a large number of ceramic filters 1 are provided in parallel in the storage container 2, only one ceramic filter 1 is shown as a representative.

In the filtration device thus constructed, the stock solution supplied into the ceramic filter 1 by the stock solution pump 3 is filtered by the ceramic filter 1 and the filtrate is stored in the filtrate receiving tank 9 and concentrated. Collects in the storage container 2. Then, when the solid S is accumulated on the inner surface 1a of the ceramic filter 1 by such an operation and the filterability is deteriorated, the open / close valve 7 is opened to send the high pressure gas for cleaning and the cleaning liquid (arrow a). Backwash Ceramic Filter 1 and Ceramic Filter 1
Can be played. At this time, the backwash drainage is taken out to the outside using the open / close valve 6 (arrow B). In this invention, since the solid matter is peeled off with a high-pressure gas and then washed with the backwash solution during the backwashing, it is possible to remove even the solid matter clogging the membrane.

Next, in the flow shown in FIG. 2, in addition to the above-described backwashing of the cleaning liquid and the high-pressure gas, the on-off valves 4 and 8 are opened to form a membrane with the stock solution (arrow D) containing high-pressure air (arrow C). I try to clean the surface. That is, the solid matter separated by backwashing is washed away with a stock solution containing high-pressure air, and the filtration surface of the ceramic filter 1 is washed from inside and outside, so that it can be completely regenerated.

Next, in the flow shown in FIG. 3, the valves 4 and 5 are closed and the valve 6 is opened to suck the filtrate in the storage container 2 by the vacuum pump V so that the membrane is backwashed with this filtrate. I have to. In this case as well, since the solid matter attached to the membrane is subjected to suction negative pressure and backwashed with the filtrate, even the solid matter clogging the inside of the ceramic filter 1 can be removed. Further, in the case of this system, as shown in FIG. 4, a large number of ceramic filters 1 ... Can be installed in a large open type storage tank 9 to form a filtration device.

Further, in the present invention, the cleaning liquid and the cleaning gas may be acted on the solid matter adhering to the ceramic filter 1 to be removed as follows. That is, in FIG. 1, the high-pressure gas is supersaturatedly dissolved in the backwash liquid introduced into the storage container 2 from the valve 7, and the dissolved gas is vaporized when the pressure of the backwash liquid drops at the membrane surface portion. The solid matter can also be peeled off. The state is shown in FIG. In the figure, reference numeral a is a bubble generated on the film surface, which pushes up the solid matter S attached to the film surface.

[0011]

As described above, according to the present invention, since the liquid cleaning fluid and the gaseous cleaning fluid act on the solid matter attached to the surface of the filtration membrane, even the fine through holes of the filtration membrane are clogged. Even a solid matter can be removed, and it is particularly effective when used for cleaning a membrane formed on the surface of a support having fine passages such as a ceramic membrane filter.

[Brief description of drawings]

FIG. 1 is a schematic flow sheet of a method for cleaning and regenerating a filtration membrane according to the present invention.

FIG. 2 is likewise a schematic flow sheet for explaining another embodiment.

FIG. 3 is likewise a schematic flow sheet for explaining another embodiment.

FIG. 4 is likewise a schematic flow sheet of a case where a ceramic filter is used in an internal pressure system.

FIG. 5 is a longitudinal sectional view of a part of the ceramic filter according to the present invention.

[Explanation of symbols]

 S solid

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Toshiji Kashide 3594-2 Hayashida-cho, Sakaide-shi, Kagawa (72) Inventor Hiroyasu Takashima 2-16-11 Yoshida-shinmachi, Kawagoe-shi, Saitama (72) Inventor Nishinokata Kan 2500-11, Ikuno-cho, Zentsuji-shi, Kagawa Inventor Osamu Yamashita 3-1-5 Saiho-cho, Takamatsu-shi, Kagawa (72) Inventor Hirozo Sasaki 1590-24 Ko, Kata-cho, Kanonji-shi, Kagawa (72) Inventor Shigeru Miyoshi 3-25 Aoba-cho, Sakaide-shi, Kagawa (72) Inventor Kimio Araki 1-2-15, Taimachi, Hachioji-shi, Tokyo

Claims (6)

[Claims] 1. A filtration membrane characterized in that a liquid and a gas cleaning fluid are applied to the fine solids (S) when removing the fine solids (S) attached to the membrane surface in the membrane filtration device. How to clean and recycle. 2. The cleaning of a filtration membrane according to claim 1, wherein in removing the solid matter S, the membrane is blown from the back side with a high-pressure gas and then the washing solution is also permeated from the back side. How to play. 3. The cleaning of a filtration membrane according to claim 1, wherein in removing the solid matter S, the membrane is blown with a high-pressure gas and a washing solution from the back side of the membrane while flowing an undiluted solution onto the membrane surface. How to play. 4. The method for cleaning and regenerating a filtration membrane according to claim 1, wherein in removing the solid matter S, a high-pressure gas is caused to flow along the surface of the membrane with the stock solution. 5. The cleaning of a filtration membrane according to claim 1, wherein the cleaning fluid that acts on the fine solid matter S is a supersaturated high-pressure fluid in which a high-pressure gas is dissolved, and that acts on the back surface of the membrane. How to play. 6. The method for regenerating and cleaning a filtration membrane according to claim 1, wherein in removing the solid matter S adhering to the membrane surface, the membrane surface is vacuum-suctioned and then blown with high pressure gas from the back surface. ..