GB768365A - Improvements in hot blast cupola installations - Google Patents

Abstract

768,365. Cupola furnaces. STRIKFELDT, W. S. June 4, 1954 [June 6, 1953; Dec. 28, 1953; Jan. 20, 1954], No. 16603/54. Class 51 (2). In a hot blast cupola installation, gases withdrawn from the cupola shaft by a duct 2 disposed below the tuyere level, pass in turn through a forehearth 3, a combustion chamber 5 in which are mounted air, water or steamheating tubes 6, a heat exchanger 10 and a fan 11 discharging into a chimney 12 from which part of the gases may be by-passed by the duct 13 into the duct 9 connecting the combustion chamber 5 and the heat exchanger 10. Air heated in the heat exchanger 10 may be supplied to the blast ring 16 of the cupola, and may be additionally heated in the combustion chamber 5 if necessary. Additional hot gases may be supplied to the combustion chamber 5 from above the tuyere level by a duct 8 and an auxiliary burner may be fitted thereto at 19. Three cupolas may serve a common forehearth, Fig. 2 (not shown). In another embodiment, Fig. 3, hot gases drawn off by a duct 3 below the tuyere level pass in turn through a blast air heater 4 supplying the tuyeres 2, a combustion chamber 5 which is also fed through a duct 7 with gases taken. from the cupola shaft above the tuyere level, and a heat exchanger 8 for heating air, water or steam. Part of the air from the heater 4 may be diverted through the branch pipe 6 to the combustion chamber 5. A final modification, Fig. 4 (not shown), leads the gases off below the tuyeres through a combustion chamber which is also arranged as a cyclone separator, and finally through a blast-air heater to a chimney above the cupola charging opening.