Method of operating a shaft furnace for the production of sintered iron ore pellets

摘要

In a method of operating a shaft furnace for the production of sintered iron ore pellets, in which the pellets are fired by introducing hot gas at the level of the furnace adjacent the opening for introducing the pellets to be fired and located at the top of the furnace and cooling air for cooling the pellets after having been heated by the hot gas is introduced into the shaft at the bottom thereof to pass upwardly through the shaft while cooling the pellets, the improvement of applying a substantial portion of the coolant air through air inlet channels distributed around the circumference of the shaft at a level of the shaft located between the bottom opening of the shaft and the burner openings at a substantial distance from both said openings as compared with the distance between the openings, to provide a temperature distribution of the coolant air flowing through the shaft such that the temperature of the coolant air flowing along and in the vicinity of the shaft adopts a value which is substantially lower around the circumference of the shaft than at the central parts of the shaft. A shaft furnace having a port for introducing iron ore pellets to be sintered in the furnace at the top of the furnace shaft, ports distributed around the circumference of the shaft adjacent the top port thereof for introducing hot gas for heating the pellets to be sintered, a port located at the bottom of the shaft for discharging sintered pellets and introducing coolant air to cool the pellets after sintering during descent thereof throught the shaft, and means for introducing coolant air throught ports distributed around the circumference of the shaft and located between the burner ports and the bottom port of the furnace at a distance from both.