JPH1085565A - Membrane separator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To operate stably a treatment tank for a long period of time without the membrane cleaning work and carry out the high concentration condensation of foul water by disposing an air diffuser pipe with an upward air jet hole on the upper section and a diffuser with an upward discharge hole on the lower section below membrane modules. SOLUTION: Vertical plane membrane modules 2 are immersed in parallel in water to be treated in a treatment tank 1. An air diffuser pipe 4 having an air suction pipe 5 and an upward air jet hole 3 is disposed on the upper section and a diffuser 8 with an upward discharge hole 7 of an ejector 6 using the water to be treated as operating water is disposed on the lower section below the plane membrane modules 2. Then ultrafine foames are jetted out of the diffuser 8 together with the water to be treated as operating water in addition to comparatively large foams from the diffuser 4. Both foams are moved upward along the modules 2 to generate the turbulent flow, remove slag to be likely to adhere to the membrane surfaces and prevent the growth of slag.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cross-flow filtration type membrane separation apparatus used for purification of waste water.

[0002]

2. Description of the Related Art Conventionally, there is known a membrane separation apparatus in which an air diffuser having an upward blowing port is disposed below a vertical flat membrane module immersed in parallel in water to be treated in a treatment tank.

[0003]

The above-mentioned conventional apparatus aims to prevent bubbles from adhering and depositing on the membrane surface by raising bubbles along both sides of each vertical flat membrane module by means of an air diffuser. However, when trying to concentrate sewage to a high concentration, the above-mentioned bubbles were relatively large and the rising speed was slow, so that it was not possible to prevent the cake from growing on the membrane surface. As a result, the operation of the processing tank was stopped, and the membrane cleaning operation had to be performed. SUMMARY OF THE INVENTION An object of the present invention is to provide a membrane separation apparatus that enables a long-term stable operation of a treatment tank to be continuously performed without performing a membrane cleaning operation, and enables high-concentration concentration of wastewater.

[0004]

SUMMARY OF THE INVENTION A membrane separation apparatus according to the present invention comprises a diffuser tube having an upward blowing port below a vertical flat membrane module immersed in parallel in the water to be treated in a treatment tank; A diffuser having a pipe and having an upward discharge port of an ejector using the water to be treated as working water is arranged with the former up and the latter down, and a relatively large bubble from the diffuser and a diffuser. Are raised along both sides of each vertical flat membrane module.

[0005] According to the membrane separation apparatus of the present invention, in addition to the relatively large bubbles rising from the air diffuser rising along both sides of each vertical flat membrane module, the diffused water is treated with ultra-fine bubbles from the diffuser. As a result, strong turbulence is generated in the water to be treated near the surface of the membrane, and the filter cake that tends to adhere to the membrane surface is removed to prevent its growth. In addition, the upward discharge from the diffuser causes a downward flow outside the vertical flat membrane module group, and the water to be treated circulates, so that the overall concentration is made uniform.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. The membrane separator shown is a processing tank
Below the vertical flat membrane module (2) immersed in parallel in the water (W) to be treated (1), a diffuser (4) having an upward blowing port (3) and an air suction pipe (5) ) And a diffuser (8) having an upward discharge port (7) of an ejector (6) that uses the water to be treated (W) as working water, and the diffuser (8) is disposed with the former facing upward and the latter facing downward. .

[0007] The flat membrane module (2) has an upper end outlet (9).
And a pair of vertical water collecting pipes (10) having slit-shaped inward openings and arranged in parallel at a predetermined interval, and reinforcing bars (11) fixed to the upper and lower sides of both water collecting pipes (10). )When,
It consists of a mesh spacer (12) for forming filtered water passage space with both edges fixed to the openings of both water collection pipes (10), and a flat membrane (13) stretched on both sides of the mesh spacer (12) In the drawings, the number is reduced for the sake of clarity.
Several tens of sheets are vertically arranged in a rectangular enclosure (15) having fixed legs (14) at intervals of 〜30 mm. The outlet (9) of the water collecting pipe (10) of each flat membrane module (2) is located above the treatment tank (1) and has a filtered water suction pipe (17) that is associated with a suction pump (16). U-shaped branch pipe (1
The hose (19) is connected to the communication port (27) of (8).

[0008] The air supply pipe (21) which is perpendicular to the flat membrane module (2) and which has a required number of blowers (20) so as to cover the entire width of the flat membrane (13). The air outlets (3) of each diffuser (4) are located between and at both ends of the adjacent flat membrane module (2). As many as possible outside each of the flat membrane modules (2) that exist in the vertical air membrane module (2), and relatively large bubbles from the air diffuser (4) rise along both sides of each vertical flat membrane module (2). It has been made to be.

As shown in detail in FIG. 4, a downwardly-treated water suction port (24) is opened immediately below an impeller (23) of the ejector (6), and a tip of the nozzle (25) is provided. Is connected to an air suction pipe (5), and further has two diffusers (2) on each side having a diffuser (8).
6) is provided. Four diffusers in total (8)
The shape and arrangement are such that the entire ultrafine bubbles ejected together with the water to be treated as working water rises along both surfaces of each vertical flat membrane module (2).
The number and arrangement of the diffusers (8) are appropriately changed according to the size of the vertical flat membrane module (2).

According to the above-mentioned membrane separation apparatus, the water to be treated (W), which is the sewage in the treatment tank (1), is converted into a flat membrane (1) by cross flow.
3) Filtered when passing through, becomes filtered water and spacer
Through the channel space held by (12), water collecting pipe (10),
It is sent to a predetermined place by a filtered water suction pipe (17) via a hose (19).

On the other hand, relatively large bubbles ejected from the upward blowing holes (3) of each diffuser (4) rise along both surfaces of each vertical flat membrane module (2). Further, below the diffuser pipe (4), the ultrafine bubbles are discharged from the diffuser (8) together with the water to be treated, which is working water, in a vigorous upward direction. As a result, the turbulent air flows from the air diffuser (4), causing strong turbulence in the water to be treated near the membrane surface. prevent. In addition, the upward discharge from the diffuser (8) causes a downward flow outside the vertical flat membrane module (2) group, and the water to be treated (W) circulates. Stable filtration is performed over a wide range from 1 to 50,000 ppm.

[0012]

According to the membrane separation device of the present invention, the synergistic effect of the sprinkler tube and the ejector allows the treatment tank to be continuously operated for a long time without performing the membrane cleaning operation.
High concentration of sewage becomes possible.

[Brief description of the drawings]

FIG. 1 is a vertical sectional view of a membrane separation device according to the present invention.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a sectional view taken along line III-III in FIG. 1;

FIG. 4 is a partially enlarged cross-sectional view of an ejector provided with a diffuser having an air suction pipe and an upward discharge port.

[Explanation of symbols]

 (1): Treatment tank (2): Vertical flat membrane module (3): Upward fumarole (4): Air diffuser (5): Air suction pipe (6): Ejector (7): Upward discharge port (8): Diffuser (W): Water to be treated

Claims (1)

[Claims] 1. An air diffusion pipe having an upward blast hole and an air suction pipe below a vertical flat membrane module immersed in parallel in water to be treated in a treatment tank, and the water to be treated is used as working water. A diffuser having an upward discharge port of the ejector is arranged with the former facing upward and the latter facing downward, and relatively large bubbles from the diffuser and ultrafine bubbles from the diffuser are both vertical flat membranes. A membrane separation device that rises along both sides of the module.