Abstract: Filtering apparatus employs both pneumatic controls and a pneumatic drive to eliminate all electrical components. The filtering apparatus includes a perforate plate and a tank with a strip of filtering media supported on the plate. Contaminated liquid is supplied from above and clean liquid is removed from below the filtering media and plate. The filtering media is advanced across the plate by conveying apparatus. The pneumatic drive for the conveying apparatus is operated by pneumatic controls and a float which actuates the drive when the liquid in the tank rises to a predetermined level as the filtering media becomes plugged. The drive is shut off when the liquid drops to a lower predetermined level.

Abstract: A filtering system includes a filter drum assembly. The system includes a filter tank with a conveyor in the bottom which removes contaminants from liquid in the tank. The filter tank also has supports therein by means of which the filter drum assembly is removably supported in the tank and can be removed as a single assembly. The filter drum assembly includes a filtering drum located in the tank and supported by a suction pipe connected by a separable fitting to a suction pump. A drive shaft is vertically positioned above the drum and is rotatably supported by an end wall of the drum. The shaft drives a wiper arm having a wiper blade in contact with the filtering drum wall and the blade is periodically moved around the drum wall to clean filter cake therefrom. The wiper arm is driven by a one-way clutch, an arm, and a fluid-operated ram which is also supported by the suction pipe.