The hollow fiber ultrafiltration membrane is made of PVDF raw material and has high impact toughness and organic chemical reliability. The uf membrane module is used throughout the use process because it will block some residues in the water. After a period of time, the blocked residue will slowly accumulate, causing blockage. At this time, it must be cleaned immediately.
1. Cleaning method of hollow fiber ultrafiltration membrane.
a. First open the air discharge valve and drain valve of the mechanical equipment;
b. Open the backwash valve, open the dosing metering pump and the backwash pump, and introduce the backwash water with organic chemicals into the uf membrane module. The total application flow of backwash water is generally 1.0-1.5 times of the total flow;
c. When checking the drain pipe, measure NaClO and close the drain pipe valve;
d. After confirming that water is discharged from the nozzle on the upper end of the hollow fiber ultrafiltration membrane, stop the NaCLO dosing metering pump, close the backwash valve, and stop the backwash pump;
e.Soak the membrane filament in the chemical solution for a period of time (usually 20 minutes). During the soaking process, the air flushing valve can be opened at intervals (usually once every 5 minutes, the air flushing time is 30 seconds);
f. Open the backwash valve, run the sodium bisulfite dosing metering pump and the backwash pump, and introduce the excess calcium hydroxide after the ro uf membrane recovers (generally delayed by 30 seconds);
g. Terminate the SBS dosing metering pump and backwash pump, close the backwash valve, and then open the air flush valve for cleaning (the delay time is 30 seconds);
h. Close the air flush valve and open the drain valve to remove the chemical solution;
i. Close the drain valve, open the backwash valve, and run the backwash pump (with a delay of 30 seconds). Stop the backwash pump, close the backwash valve, then open the air flush valve to hydrolyze the acidification tank (generally delayed by 30 seconds), repeat this whole process until the overflow water body can meet the requirements;
j. Make sure that the air flush valve and the backwash valve are closed, and the backwash pump is in a dormant state.
2. Backwashing and air washing of hollow fiber ultrafiltration membrane.
A. Close the water seepage valve and stop the power supply of the centrifugal pump;
B. Open the exhaust valve;
C. Close the filter valve, run the backwash pump, open the backwash valve, and return the filtered water from the backwash storage tank to the ro uf membrane. When backwashing, run the organic chemical dosing metering pump and add organic chemicals to the backwash water. The common organic chemical is calcium hydroxide, the concentration value should exceed 50mg/L (ascl2). The amount of backwash water used is 1.0-1.5 times the total flow;
D. After backwashing for a period of time (usually 30-60 seconds), close the backwash valve and terminate the backwash pump;
E. Open the air exhaust valve and open the air flush valve to flush for a period of time (usually 30-60 seconds);
F. Close the air flush valve and open the drain valve;
G. After the drain pipe is completed, close the drain valve;
H. Open the power supply centrifugal pump and water seepage valve;
I. After confirming that the hollow fiber ultrafiltration membrane is filled with water and purged all the air, close the air purge valve.