Air inlet filter for gas turbine engine

Claim 1

An air inlet filter assembly for filtering debris from air for a gas turbine engine, said gas turbine engine having an inlet end for receiving the filtered air, said air inlet filter assembly comprising: a plenum box fixedly mounted to and surrounding the inlet end of the engine, said plenum box including an inlet for receiving debris laden air; an annular air filter rotationally mounted within said plenum box intermediate the inlet of the plenum box and the inlet end of the engine, said annular air filter being operative to filter debris from air passed therethrough; an air pressure nozzle fixedly mounted in said plenum box and adjacent the inner circumferential surface of said annular air filter, said air pressure nozzle being selectively operable to direct pressurized air generally radially outwardly and through said annular air filter to loosen debris thereon; a suction nozzle fixedly mounted within said plenum box and adjacent the outer circumferential surface of said annular air filter and generally radially opposite the air pressure nozzle, said suction nozzle being selectively operable to remove the loosened debris from the annular air filter; driving means for selectively rotating said annular air filter about its central axis and relative to the plenum box, the air pressure nozzle and the suction nozzle such that the entire annular air filter passes between the air pressure and suction nozzles with each rotation, whereby simultaneous operation of said air pressure nozzle, said suction nozzle and said driving means enables the entire annular air filter to be cleaned with each rotation of said annular air filter; at least one flexible seal mounted intermediate said air filter and said plenum box, said flexible seal being operative to prevent debris from bypassing the air filter and entering the engine, is generally annular in configuration and is biased in radially inward direction to prevent the inward movement of debris toward the turbine engine and is fixedly mounted to the plenum box and is biased against the annular air filter; and an array of seal air pressure nozzles disposed generally adjacent and radially inwardly from said flexible seal, said array of seal air pressure nozzles being selectively operable to direct air radially outward against said flexible seal to facilitate rotation of said air filter and to prevent movement of debris past the seal.