Patent ID: 7435351

Claim:
A method for removing backwash fluid and solids from a filter apparatus with circulating compressible filter media during backwash comprising: directing air in a filter apparatus to circulate an uncompressed bed of compressible filter media and to elevate a localized portion of air-elevated backwash fluid to a highest level above a lower fluid surface level and through a partition near the top of a filter apparatus; and directing backwash fluid and solids away from re-entering the partition by receiving air-elevated backwash fluid from the localized portion of backwash fluid in at least one conveyance, comprising a trough, the trough being contiguous to and in contact with the localized portion of the air-elevated backwash fluid for capturing the air-elevated backwash fluid, the trough being adjacent to and positioned above the partition, and the trough being in fluid communications between at least one opening in the partition and with an outlet.