Backwashing status:
With the accumulation of impurities in the packing layer, the loss of internal pressure head will increase. When the loss of inlet and outlet pressure head reaches the set value, the system will automatically activate the pressure differential device to convert it to the backwash state. When the backwash is finished, the hydraulic valve changes the direction of the water supply to realize filter tank’s backwash one by one, which is more convenient to clean the accumulated impurities.
When the system is in the backwash state, filtration still continues. The standard filter tank to be backwashed is not in filtration state, while other standard filter tanks in the system are still in normal filtration state. A part of the filtered clean water is used to backwash the standard filter tank, and the rest of the filtered clean water is sent to the clean water tank. Backwash sewage is discharged through the backwash outlet of the hydraulic valve. In the high speed filter tank’s efficient filtration system, the special water collector design can make the sand rub each other, maximize the backwashing efficiency, reduce the required backwash water (clean water); at the same time, there is no sand loss phenomenon during backwashing. The backwashing time of one standard filter tank is 3 minutes. After the backwashing is finished, the loss of the pressure head inside the standard filter tank is reduced to a reasonable range, the constant pressure device gives a recovery signal, the hydraulic valve is restored to the filtering state, and the the next standard filter tank is ready to enter the backwashing state. The system’s backwashing can also be controlled by time, and the default backwashing time is 4 hours, user can adjust the time according to the working conditions. Dual system control is regardless of primary and secondary, which system first come first execution.