How often is the quartz sand filter backwashing

Quartz sand filter, it USES quartz sand as filter medium, under certain pressure, the high turbidity water by a certain thickness of granular or the grain of the quartz sand filter, effectively intercept to remove the suspended solids in the water, organic matter, colloid particles, microorganism, chlorine, smelling and some heavy metal ions, etc. , to reduce water turbidity, water quality purification effect of a high efficiency filtration equipment. Principle figure it out, then we will understand, quartz sand filter is a filter, mechanical filter, when the filter to intercept the large amount of impurities such as fine particulate matter, has formed a certain resistance, water pressure-out increased water pressure gauge, and the water pressure gauge is small, intercept the more impurities, water pressure gauge performance values and the greater the water pressure value is smaller.
then how long the filter backwashing once, in particular, no fixed time depending on the specific situation, we generally in the in and out of the water are equipped with a pressure gauge, differential pressure 1 kg will have to reverse wash and wash, backwashing time usually in 3 - 5 minutes, is 2 - washing 3 minutes.
in the case, you must want to change the filter material:
1, the filter backwash 'frequent, shorter effective during operation.
2, early after routine back flush filter press can't decline.
3, began to flow to normal after backwashing, flow decrease soon.