Self-cleaning rotary fluid filtration system

Claim 1

A combined pump and self-cleaning centrifugal contamination separator comprising: a housing having a longitudinal axis; an inlet in said housing, and extending along said axis, for receiving fluid subject to contamination by the presence therein of undesirable suspended solid particles; means, including a cylindrical filter screen having radially inner and outer surfaces, for providing within said housing an inner chamber radially inward of said filter screen and an outer generally annual chamber radially outward of and encircling said cylindrical screen; a first discharge outlet in said housing communicating with said inner chamber; a second discharge outlet in said housing communicating with said outer chamber; means, including a centrifugal impeller, for rotating said cylindrical filter screen and for spinning the contaminated fluid around said outer annular chamber at a relatively high velocity while at the same time pumping that contaminated fluid radially inward toward said inner chamber, the solid contaminants centrifuging radially outward to facilitate their separation and removal through said second discharge outlet while the remaining clean fluid passes radially inward through said cylindrical filter screeN to said inner chamber from which it may be exhausted through said first discharge outlet, some of the separated contaminants tending to adhere to and collect on said radially outer surface of said screen; and filter cleaning means for back-flushing said filter screen to remove from said outer surface those contaminants tending to collect thereon and including a stationary hydrodynamic skid positioned radially inward of said filter screen adjacent to a very small section of tee rotating inner surface and tear drop shaped to cause a small portion of the clean fluid to be diverted and driven back out through an incremental area of said screen, in the direction from said radially inner to said radially outer surface, thereby subjecting the entirety of the rotating filter screen to the cleaning action of the reverse fluid flow during each revolution.