BACKWASHABLE SAND FILTER
Sand filters are a common type of side stream filtration system.
Sand filters direct fluid into the top of their tank(s) and onto the surface of a bed of specified sand and/or other media.
As the cooling water flows through the bed of sand media, suspended solids and other particles are captured within the
upper layer of media. The water moves downward, passing into a drain at the bottom of the filter tank and discharging
through an outlet pipe.
Sand filters are usually very efficient at removing the extremely fine and low density particles that cooling towers scrub
from the air. Therefore, they generally have very high filtration rates. However, sand filters work less effectively
with high density sand-like materials because these materials cannot be properly removed by backwashing.
The development of high efficiency sand filters has revolutionized cooling water filtration. Airborne contaminants can now
be cost effectively removed with a backwashing filter.