Patent ID: 6468421
Filing Date: 2002-10-22
Classification: B01D

Abstract:
A filtering apparatus for removing solid particles from a liquid, comprising in combination:(a) a substantially vertical, pressure-tight cylindrical housing having upper and lower ends; (b) a filter assembly coaxially mounted within an interior of said housing, said filter assembly comprising a perforated cylinder and a flexible fabric filter, said perforated cylinder having an inner circumferential surface defining an internal filtered liquid passage and an outer circumferential surface supporting said flexible fabric filter thereon; (c) a liquid inlet in said housing adjacent the upper end of said filter assembly and including an inlet valve for opening and closing said liquid inlet; (d) a liquid outlet connected for draining filtered liquid from said internal filtered liquid passage through a bottom portion of said housing and including an outlet valve for opening and closing said liquid outlet; (e) a drain in the lower end of said housing for draining off accumulated solids from the housing and including a drain valve for opening and closing said drain; (f) a vacuum-break valve for providing exterior air into the interior of said housing when said vacuum-break valve is opened; (g) a wash-down apparatus in the upper end of said housing for directing a wash liquid under pressure against an outer surface of said flexible fabric filter and including a wash-down valve for opening and closing said wash-down apparatus; and (h) a controller having a pressure differential sensor connected for sensing the pressure differential between the liquid outlet and the interior of said housing upstream of said fabric filter, said controller adapted to close said inlet and outlet valves and open said drain, vacuum-break, and wash-down valves to initiate a wash-down of said filter assembly when a predetermined pressure differential is attained, wherein said controller is adapted to open said vacuum-break valve after closing said inlet and outlet valves to cause the flexible fabric filter to pulse and thereby initially dislodge entrapped solid particles therefrom before said wash-down.