Patent ID: 6358406
Filing Date: 2002-03-19
Classification: B01D

Abstract:
A vacuum fluid filter for continuously filtering contaminated fluid in a tank comprising:a) a right cylindrical filter drum having a perforate section and an imperforate section disposed in said tank and supported for rotation about a central longitudinal axis on a tubular shaft, said tubular shaft journaled at a plurality of points in bearings so as to be freely rotatable or independently rotatable from said filter drum, said imperforate section of said filter drum being positioned upwardly in said tank when said filter drum is stationary; b) a level controller for controlling the level of contaminated fluid in said tank such that when said filter drum is stationary, the contaminated fluid level is maintained above the perforate section but below the top of the imperforate section of said filter drum; c) an idler drum supported for rotation about an axis substantially parallel to the axis of said filter drum; d) a continuous permanent filter belt having a portion thereof wrapped substantially around the periphery of said filter drum and in contact with the imperforate section thereof, and a portion thereof wrapped around said idler drum; e) a means for withdrawing filtered fluid from an interior of said filter drum comprising a plurality of suction pipes extending downwardly from said tubular shaft, said plurality of suction pipes each having a single inlet end continuously located proximate the lowest point of said filter drum and providing fluid communication between the interior of said filter drum and an interior of said tubular shaft, said vacuum fluid filter configured to maintain the level of filtered fluid in said filter drum above each of said inlet ends to thereby facilitate continuous filtration throughout operation and indexing of said vacuum fluid filter, said tubular shaft only having suction pipes that extend from a bottom side thereof; f) means for sensing differential pressure between the interior and exterior of said filter drum; g) means for sensing rotation of said filter drum; h) means for effecting rotation of said filter drum so as to effect advancement of said filter belt responsive to said means for sensing differential pressure, wherein rotation commences when the differential pressure reaches a predetermined level, said means for effecting rotation further responsive to said means for sensing rotation of said filter drum wherein rotation ceases when said filter drum completes one revolution; and i) means for removing contaminants from said filter belt.