Patent ID: 8795521

Claim:
A filter system for removing contaminants from a liquid flowing through the system where the system comprises: a vessel having an upper end, a lower end, and an inlet in the upper end for receiving a contaminated liquid flow, said vessel adapted to hold a quantity of particulate filter material therein; at least one lateral screened enclosure supported within the vessel at the lower end, the lateral screened enclosure comprising an outlet through which filtered liquid can exit the vessel; a scrubber apparatus connected to said vessel by which the filter material can be cleaned, wherein said scrubber apparatus comprises: (i) a pump having a suction and a discharge; (ii) a scrubber tube located inside the vessel, the scrubber tube having an enclosed top and bottom, a scrubber tube inlet at the top for receiving flow from the pump discharge, a scrubber tube outlet in a sidewall of the scrubber tube, and a scrubber tube opening at the bottom through which a nozzle extends so flow is discharged outside of the scrubber tube; (iii) a filter tube having a screened wall construction contained within the scrubber tube, wherein an annulus is defined between the scrubber tube and the filter tube, wherein said filter tube comprises an inner passage which receives a flow of filter material and contaminants suspended in water from the scrubber tube inlet, a conical tube having an upper end and a lower end, wherein the upper end of the conical tube has an outer diameter that is larger than an outer diameter of the lower end of the conical tube, wherein the upper end of the conical tube is connected to a lower end of the filter tube and a lower end of the conical tube is hydraulically connected to the nozzle, the nozzle comprising a flow restricting orifice that is hydraulically connected to the inner passage of the filter tube via the conical tube, wherein the flow restricting orifice reduces a pressure to which the vessel is subjected during a backwash cycle and discharges filter material and water into the vessel, wherein flow of contaminants and water through the inner passage may pass through the screen wall into the annulus for discharge through the scrubber tube outlet and flow of filter material and water may pass through the nozzle for discharge into the vessel; and said pump suction connected to receive flow of filter material and contaminants suspended in water from the interior of said vessel and exiting the pump discharge, wherein said flow is directed to flow through the inner passage, and filter material suspended in water pass through the orifice of the nozzle, causing the liquid and particulate filter material within the vessel to assume a flow path which scrubs the filter material inside the vessel.