AIR HEATER Russian patent published in 2002 - IPC

FIELD: metallurgy, particularly, high-temperature heating of blast-furnace blast. SUBSTANCE: blast-furnace air heater has nozzle, under-nozzle space, air heater, central combustion chamber connected with burner nozzle located in combustion chamber in zone of under-nozzle space. Combustion chamber in zone of under-nozzle space is expanded, and burner and air header with adjacent annular slot for air supply to burner nozzle are located inside expanded part of combustion chamber - in zone of under-nozzle space. Inner diameter of expanded cylindrical part of combustion chamber equals to 1.3-1.5 of inner diameter of main part of combustion chamber. EFFECT: higher stability of air heater, its operating reliability and economic efficiency. 2 cl, 2 dwg