Fuel burning air heating apparatus

Claim 1

A BURNER HEATING APPARATUS COMPRISING IN COMBINATION, MEANS FORMING A TUBULAR COMBUSTION CHAMBER HAVING A LARGER UPSTREAM PORTION AND A SMALLER DOWNSTREAM PORTION, FUEL BURNER MEANS IN ONE END OF SAID COMBUSTION CHAMBER ADAPTED TO PRODUCE AN OUTWARDLY FLARING FLAME WHICH STRIKES THE WALL OF THE COMBUSTION CHAMBER AT A CIRCUMFERENTIAL REGION WHERE THE LARGER UPSTREAM PORTION OF THE COMBUSTION CHAMBER MERGES WITH THE SMALLER DOWNSTREAM PORTION THEREOF, MEANS FORMING AN ANNULAR COMBUSTION AIR INTAKE DUCT OF APPROXIMATELY UNIFORM RADIAL WIDTH SURROUNDING SAID COMBUSTION CHAMBER IN HEAT EXCHANGE RELATIONSHIP WITH THE OUTER SURFACE OF THE COMBUSTION CHAMBER FOR SUBSTANTIALLY THE ENTIRE LENGTH OF SAID COMBUSTION CHAMBER, MEANS FORMING AN AIR HEATING DUCT SURROUNDING SAID COMBUSTION AIR INTAKE DUCT, SAID AIR HEATING DUCT CLOSELY SURROUNDING AND BEING IN HEAT EXCHANGE RELATIONSHIP WITH THE COMBUSTION AIR INTAKE DUCT ALONG THE LARGER PORTION OF SAID COMBUSTION CHAMBER, AND MEANS FORMING A DEAD AIR SPACE AROUND THE PORTION OF THE COMBUSTION AIR INTAKE DUCT SURROUNDING THE SMALLER PORTION OF SAID COMBUSTION CHAMBER AND INWARD OF SAID AIR HEATING DUCT.