JPH06226065A - Membrane washing method - Google Patents

Abstract

(57) [Summary] [Purpose] The purpose is to efficiently use the treated water with a minimum amount when cleaning the solid-liquid separation membrane of the water treatment device. [Structure] The separation membrane can be completely exfoliated by simultaneously performing air washing and back washing with water so that the exfoliated portion can be completely pushed out of the system using raw water. Constitute.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solid-liquid separation device for a water treatment device, and more particularly to a method for cleaning a microfilter membrane and an ultrafilter membrane.

[0002]

2. Description of the Related Art Conventionally, a method of washing the surface of a membrane by bubbling with air or the like, or backwashing with water, and then draining turbidity out of the system.

However, according to this method, it is insufficient to remove the turbidity or the like adhering to the film surface, and with the drain,
It is difficult to completely discharge suspended matter out of the system. or,
The method of discharging treated water to the outside of the system has a drawback that the water recovery rate is lowered.

[0004]

SUMMARY OF THE INVENTION According to the present invention, in order to efficiently wash a membrane with a minimum amount of treated water and efficiently perform backwashing with air and backwashing with treated water, the generated washing wastewater is treated with raw water. It is designed to be pushed out of the system, and it is to provide a cleaning method that keeps the membrane stable for a long period of time.

[0005]

According to the present invention, the washing with air and the backwashing with water are carried out at the same time to completely remove turbidity and push it out of the system by using raw water. The minimum amount of treated water used for cleaning is
This is configured as an efficient cleaning method.

[0006]

[Example] An example will be described with reference to FIG. In the filtration step, raw water is supplied to the membrane module 2 by the supply pump 1 through the supply valve 10. The raw water is solid-liquid separated in the membrane module, and the treated water that has permeated the membrane passes through the treated water valve 6 and is collected in the raw water tank 8. Water that did not permeate through the membrane
Returned through the circulating water valve.

At the time of cleaning, first, the supply pump is stopped, the supply water valve and the treated water valve are closed, and the cleaning water valve 5 is opened. After that, the air washing valve 3 and the back washing water valve 7 are opened, and the air washing blower 9 and the back washing pump 11 are operated to remove turbidity and the like on the membrane surface. Next, in order to discharge the separated suspended matters from the inside of the membrane module to the outside of the system, close the air washing valve and the backwash water valve, stop the air washing blower and the backwash water pump, open the supply water valve, and supply. The water pump is operated to supply raw water into the membrane module, and the cleaning drainage inside the module is discharged from the system through the cleaning drain valve. After washing, return to the filtration process.

[0008] The backwash water washing is not continuous but is performed intermittently during the air washing, and the use of treated water can be further reduced. Note that FIG. 2 shows a time chart for explaining the open / closed state of the valve.

[0009]

The performance of the membrane can be maintained for a long period of time, the treated water used for cleaning is minimized, and the water recovery rate is increased.

[Brief description of drawings]

FIG. 1 shows a system configuration of the present invention.

FIG. 2 is a time chart showing a valve opening / closing state during operation.

[Explanation of symbols]

 1 Supply pump 2 Membrane module 3 Air cleaning automatic valve 4 Circulating water automatic valve 5 Cleaning drainage automatic valve 6 Treated water automatic valve 7 Backwash water automatic valve 8 Treated water tank 9 Washing blower 10 Supply water automatic valve 11 Backwash pump

Claims (1)

[Claims] 1. A method for cleaning a membrane surface of a microfilter membrane for solid-liquid separation and an ultrafilter membrane of a water treatment device, comprising:
A method of washing the membrane surface by washing the membrane surface with air, and at the same time flowing back washing water from the membrane back surface to separate suspended substances, and then introducing raw water and discharging it out of the system.