Abstract: A clarifier allowing increased fluid pressure differentials across the filter septum is arranged with one face of the septum exposed to the contaminated liquid and the opposite face exposed to the suction pressure of a pump with the discharge of the pump capable of being redirected to backflush through the filter septum, such backflushing being carried out sequentially through small area segments of the septum. The return of a flight conveyor may be moved selectively into and out of scraping or wiping relation with the filter and filter wiping and backflushing may be automatically controlled.

Abstract: Method and apparatus for clarifying liquids wherein a flight conveyor in the settling tank has a forwarding run for removing sludge from the bottom of the tank and a return run which is selectively moved into and out of wiping cooperation with a filter between the settling tank and a clean-liquid tank, and a filter backwasher in the clean tank is selectively operable to progressively backwash the filter, and both the wiping and backwashing being accomplished in accordance with the clogged condition of the filter.