Patent ID: 6638422
Filing Date: 2003-10-28
Classification: B01D,C02F

Abstract:
A process liquid filtration apparatus for removing particulates from a flowing process liquid having a predetermined specific gravity, comprising:a) a source of said particulate laden process liquid; b) a filter chamber having an inlet port for receiving said particulate laden process liquid and an outlet port for discharging filtered process liquid therefrom; c) a composite filter bed within said filter chamber formed by distinct filter particles having a specific gravity lower than the said predetermined specific gravity of said process liquid; d) means for conveying particulate laden process liquid into said filter chamber from said source thereof for passage through said composite filter bed for separation of said particulates from said process liquid and discharge of filtered process liquid through said outlet port of said filter chamber; e) means communicating with said outlet port for conveying said filtered process liquid away from said filter chamber for re-use as a non-contaminated process liquid; f) at least one backwash spray head mounted within said filter chamber; g) means connecting said at least one backwash spray head to the outlet port of said filter chamber to convey filtered process liquid from said filter chamber to said at least one backwash spray head; h) means interposed in said means connecting said at least one spray head to said filter chamber selectively operable to initiate conveyance of said filtered process liquid to said at least one spray head in response to a reduced flow rate when said filter bed is so clogged by particulates that the rate of flow of said filtered process liquid drops below a selected predetermined flow rate, whereby said filter bed is backwashed to remove said particulates therefrom; and i) said means responsive to said reduced flow rate from said filter chamber includes a sensor that measures said flow rate, a plurality of solenoid valves, a filtered process liquid reservoir, a pump and an electronic control system interconnecting said sensor, valves reservoir and pump.