How to clean quartz sand filter?

How to clean quartz sand filter?

Quartz sand filter is the use of quartz sand as a filter medium, under the corresponding pressure, the high turbidity of water through the corresponding thickness of granular or non-granular quartz sand filtration, interception to remove the suspended matter in the water, organic matter, colloid particles, microorganisms, to reduce the turbidity of water, water purification effect of equipment. So, how to clean quartz sand filter?

Start preparation

Check whether the filter body and all kinds of valves, piping instruments and accessories are in good condition;

Whether the metering pump is in good condition Check whether the original pump electrical equipment, various on-site instruments and various ancillary facilities are in good condition;

Confirm that all discharge forward wash and reverse wash valves are closed;

Filter exhaust valve after water closed.

Boot operation

Operation workflow: exhaust → washing → backwash (two) → positive wash → water making → backwash (one) → drainage → soda scrub

Note: The backwash (I) process should be started when driving after a long period of outage.

1 Exhaust and rinse

1) The exhaust sequence is set during the initial debugging because there is air inside the equipment. Open the inlet valve and exhaust valve of the quartz sand filter. After the exhaust valve is discharged, close the exhaust valve and open the forward washing exhaust valve for reserve.

2) Various filter layers cannot be formed in time during the initial operation of the equipment, so the filtering effect is not good, so the flushing sequence is set. Open the filter inlet valve and forward wash discharge valve and run until the effluent turbidity is less than or equal to 2mg/L.

2 Operation Cycle

Open the filter inlet valve and outlet valve, and open the metering pump of the original water pump. When running to the inlet and outlet pressure difference or set the water, the running cycle ends. The running time can be adjusted according to the actual situation on site.

3 Soda Scrub

Close the water inlet valve and water outlet valve, open the forward wash discharge valve and air inlet valve, and reverse wash the water inlet valve. Scrub the mixture of air and water for about 10 minutes.

4Backwash

The purpose of backwashing is to loosen the filter layer and wash away the filter layer, so as to clean the filter layer. The length of recoil time is related to the amount of filter cut and recoil velocity.

Backwash drainage should not contain normal particulate filter media.

Backwash close water inlet valve outlet valve, open backwash discharge valve backwash valve, backwash flow is generally controlled by the filter material is not rushed out, generally about three times the running time.

Backwash ends when the transparency of water and water is similar. At the end of backwashing, the backwashing flow rate gradually decreases to facilitate the stratified settlement of filter material according to the particle size.

5 Forward Wash

Open the forward washing discharge valve of the filter inlet valve. The forward washing flow is the running flow, and the time is generally 20 minutes. The equipment can continue to be put into operation after the forward washing is completed when the water is clear and transparent.

6 Drainage

Open the filter exhaust valve and positive wash discharge valve, and drain the water in the filter to 200mm on the filter material layer. The time should be determined according to the specific situation.