Abstract: A system for filtering liquids, such as coolant liquid from process machinery. The system includes an improved liquid storage tank having a partition dividing the tank into a clean tank for receiving clean liquid from a filter for return to the process machinery, and a dirty tank for receiving process or dirty liquid from process machinery. The storage tank further includes a second partition forming a blowdown chamber and a recirculation chamber below the blowdown chamber, the two chambers being coupled together by a valve which can be opened and closed depending upon the cycle of operation of the system. The recirculation chamber is coupled by a filter pump to the inlet of the filter. The filter has a return line to the clean tank and a blowdown line to the blowdown chamber. The blowdown chamber has a conical bottom and the recirculation chamber has a sidewall provided with tangential inlet ports communicating with the dirty tank.

Abstract: An improved filter plate of the type used with a vertical stack of other such plates to form an industrial filter of the type known as a horizontal plate filter. The improved filter plate has a generally upright side wall, and a divider plate or transverse planar plate portion secured to the side wall below the upper margin thereof. An open top trough is formed in the divider plate to receive the filtrate passing through a filter medium above the filter plate when the latter forms a part of a horizontal plate filter. A hole in the side wall permits the filtrate to be removed from the trough. The filter plate further includes a fluid inlet conduit and an air vent/blowdown conduit extending through the side wall into the space below the divider plate. The trough and removable conduits eliminate the need for fixed baffles for use as the fluid inlet, outlet, and blowdown means as found in a conventional filter plate.

Abstract: Disclosed is an improved liquid filter in which contaminated liquid is pumped into an inlet chamber, through a filter element, into an outlet chamber and out of the filter through an outlet pipe. The inlet and outlet chambers have compartments which hold compressed air. When the filter element becomes clogged with contaminants, inlet and outlet valves are closed, sealing off the filter. A vent valve is then opened to quickly exhaust the compressed air in the inlet air compartment. This allows the compressed air in the outlet air compartment to energetically force liquid back through the filter element thereby dislodging the deposited contaminants. The compartments and a liquid column between them are sized so that a discharge of liquid from the inlet compartment during the venting thereof is prevented.

Abstract: A liquid filter apparatus wherein an elongated sheet of filter media is movable along an inclined support at the bottom of a receiving tank for dirty liquid below which is a collection tank for filtered liquid. The periphery of the collection tank is sealed by clean liquid supplied from an auxillary reservoir at a pressure greater than the liquid in the receiving tank. A suction pump attached to the outlet from the collection tank helps to maintain flow of clean liquid through the media while filtered out material is accumulated on its upper surface. Fresh filter media is pulled into position from a supply roll to replace loaded filter media by drive means controlled to operate automatically after the pressure in the collection tank is substantially equalized temporarily with that in the receiving tank.

Abstract: A filter apparatus wherein filter media is submerged in liquid being filtered and suction is employed under the media to increase the flow through it. The filter media in elongated strip form is supported for movement in one direction on an inclined endless pervious conveyor comprised of rigid plate members fixed to a pair of drive chains. A receiving tank for dirty liquid is above the conveyor and media with a lower tank for clean liquid below the conveyor with the sides and ends of the lower tank being constantly sealed in order to maintain reduced pressure therein to enhance flow through the media. Filtered liquid at a somewhat higher pressure is supplied at the sides of the conveyor and at end walls of the receiving tank to prevent any migration of dirty liquid into the lower tank at the periphery of the lower tank.

Abstract: A filter apparatus wherein filter media is submerged in liquid being filtered and suction is employed under the media to increase the flow through it. The filter media in elongated strip form is supported on an incline for movement in one direction by an endless pervious conveyor. A receiving tank for dirty liquid is above the conveyor and media with a lower tank for clean liquid below the conveyor with the sides and ends of the lower tank being constantly sealed in order to maintain reduced pressure therein to enhance flow through the media. Filtered liquid is supplied at the sides of the conveyor and at an end wall of the receiving tank to prevent any migration of dirty liquid into the lower tank at the periphery of the lower tank. Advancement of the filter media is controlled automatically in response to variations in the pressure differential on opposite sides of the media which varies in proportion to the dirt load of the media.