Abstract: A method of concentrating solids in a liquid suspension using a microporous filter assembly having a plurality of hollow microporous, elastic membranes within a vessel, the method including the steps of applying the suspension to an outer surface of the hollow fibers whereby a portion of the suspension passes through the fibers walls and at least a portion of the solids is retained on or in the hollow fibers or within the vessel as suspended solids; dislodging the retained solids from the fibers by applying a gas under pressure after opening the vessel to atmospheric pressure.