Patent EA-001012-B1 (EA)
Title: Filter with counter flow clearing
Inventor: OBST YURI
IPC: B01D29/01
Filed: 1997-12-01
Abstract: 1. A filter comprising: a filter medium, for filtering contaminants from a process fluid, having a filtration side on which said contaminants collect and a filtrate side from which filtrate flows; a counter-flow generator comprising at least one fluid outlet, located on said filtrate side that directs a localised stream of counter-flow fluid from said filtrate side to said filtration side of said filter medium to thereby dislodge said contaminants which have collected on said filtration side of said filter medium, means for moving said counter-flow generator and thereby said localised stream of counter flow fluid, relative to and over a substantial portion of said filter medium, clearing-flow generator comprising at least one fluid outlet, located on said filtration side that directs a localised stream of clearing-flow fluid, with a velocity having a component which is parallel to the surface of said filter medium, onto said filter medium, and means for moving said clearing-flow generator and thereby said localised stream of clearing-flow fluid, relative to and over a substantial portion of said filter medium. 2. A filter according to claim 1 wherein said localised stream of clearing-flow fluid is directed onto an area adjacent to the area on said filter medium through which said localised stream of counter-flow fluid flows. 3. A filter according to claims 1 or 2, wherein said localised steam of counter-flow fluid and said localised stream of clearing-flow fluid move substantially in unison for at least a portion of their said movement. 4. A filter system according to claims 1, 2, or 3 wherein said filter medium is substantially cylindrical in shape.  5. A filter according to claim 4 wherein said counter-flow generator additionally comprises a manifold with a plurality of fluid outlets, said manifold being rotatable about an axis within said substantially cylindrical filter medium to traverse said filter medium. 6. A filter according to claims 4 or 5 wherein said clearing-flow generator additionally comprises a manifold with a plurality of fluid outlets, said manifold being rotatable about an axis within said substantially cylindrical filter medium to traverse said filter medium. 7. A filter system according to claims 4, 5 or 6 wherein said substantially cylindrical filter medium is substantially immersed in a vessel containing said process fluid. 8. A filter comprising: substantially planar inclined filter medium for filtering contaminants from a process fluid, wherein said process fluid flows downwards from the upper end of said inclined filter medium, having filtration side on which said contaminants collect and a filtrate side from which filtrate flows, a counter-flow generator comprising at least one fluid outlet, located on said filtrate side that directs a localised stream of counter-flow fluid from said filtrate side to said filtration side of said filter medium to thereby dislodge said contaminants which have collected on said filtration side of said filter medium, and means for moving said counter-flow generator and thereby said localised stream of counter-flow fluid, relative to and over a substantial portion of said filter medium. 9. A filter as claimed in claim 8, wherein said filter medium bows in the direction of flow of said filtrate and, when exposed to said localised counter-flow, bows in the direction of said counter-flow fluid to thereby assist in the dislodgment of said contaminants from said filter medium. 10. A filter as claimed in claim 8 or 9, additionally comprising a filtrate collection means positioned under said filter medium. 11. A filter as claimed in claim 8, 9 or 10, wherein counter-flow generator additionally comprises a manifold with a plurality of fluid outlets producing an elongate counter-flow steam across said inclined filter medium which moves relative to and over a substantial portion of said inclined filter medium. 12. A filter as claimed in claim 8, 9, 10 or 11 additionally comprising clearing-flow generator comprising at least one fluid outlet, located on said filtration side that directs a localised stream of clearing-flow fluid, with a velocity having a component which is parallel to the surface of said filter medium, onto said filter medium, and means for shifting said clearing-flow generator and, correspondingly, said localised stream of clearing-flow fluid, relative to and over a substantial portion of said filter medium. 13. A filter according to claim 12, wherein said localised stream of clearing-flow fluid is directed onto an area adjacent to the area on said filter medium through which said localised stream of counter-flow fluid flows. 14. A filter according to claim 13, wherein clearing-flow generator additionally comprises a manifold with a plurality of fluid outlets thereby producing an elongate clearing-flow stream. 15. A filter according to claims 12, 13 or 14, wherein said localised steam of counter-flow fluid and said localised stream of clearing-flow fluid move substantially in unison for at least a portion of their said movement. 16. A filter system according to claims 8, 9, 10, 11, 12, 13, 14 or 15 additionally comprising a flow distribution means located adjacent said upper end of the top side of said inclined filter medium adapted to provide an even distribution of process fluid onto said filter medium.