Air heating burner

Claim 1

IN COMBINATION WITH A DUCT, BURNER APPARATUS FOR HEATING A STREAM OF AIR FLOWING IN THE DUCT FROM AN UPSTREAM END THEREOF TO A DOWNSTREAM END THEREOF, SAID BURNER APPARATUS BEING OPERABLY POSITIONED IN THE DUCT INTERMEDIATE THE UPSTREAM AND DOWNSTREAM ENDS THEREOF AND COMPRISING, IN COMBINATION: FUEL SUPPLY MEANS FOR DELIVERING A STREAM OF FUEL TO THE BURNER; ANNULAR FUEL NOZZLE MEANS FOR RECEIVING AT LEAST A PORTION OF THE FUEL STREAM; FLAME STABILIZING MEAN DOWNSTREAM OF THE FUEL NOZZLE MEANS FOR RECEIVING AN ANNULAR STREAM THEREFROM AND FOR INITIATING AND STABILIZING THE COMBUSTIBLE REACTION OF AT LEAST A PORTION OF THE ANNULAR FUEL STREAM; PERFORATE WALL MEANS DEFINING A PRIMARY MIXING CHAMBER HAVING AN OPEN UPSTREAM END IN COMMUNICATION WITH THE STABILIZING MEANS AND AN OPEN DOWNSTREAM END; BAFFLE MEANS IN THE DUCT DISPOSED TRANSVERSELY OF THE BURNER FOR DIRECTING THE AIR FLOWING IN THE DUCT PAST THE BURNER AND FOR INCREASING THE VELOCITY THEREOF TO 1400 TO 2600 FEET PER MINUTE; MIXING BAFFLE MEANS DISPOSED DOWNSTREAM OF THE OPEN DOWNSTREAM END OF THE PRIMARY MIXING CHAMBER AND TRANSVERSELY THEREFO AND CONSTITUTING SECONDARY MIXING MEANS; AND MEANS FOR INTERPOSING A LAYER OF COOL AIR ADJACENT THE UPSTREAM SIDE OF THE MIXING BAFFLE INTERMEDIATE THE BAFFLE AND FUEL FLOWING FROM THE PRIMARY MIXING CHAMBER.