Backwash sand filter is made of
cylindrical double-tank, it adopts the filter mediums such as
silica sand and scree with the grain size of 0.**1.0mm, the filter
accuracy can be changed by alternation of grain of sand. Clean
water in the double-tank directly backwashes the impurities in the
other tank, and so making it the most efficient filter at present
to dispose of the organic and inorganic impurities in the water,
and generally applied for filtering the surface water (such as
river and pond water). Sand filter can be used in combination with
screen filter.
