METHOD FOR PREHEATING STEEL SCRAP BY EXHAUST GAS FROM STEELMAKING ELECTRIC FURNACE

摘要

ABSTRACT OF THE DISCLOSUREA method for preheating steel scrap by exhaustgas from a steelmaking electric furnace, which comprises:directing, when manufacturing steel from steel scrap inan electric furnace, exhaust gas produced in the electricfurnace to an exhaust gas combustion chamber provided alonga discharge duct for the exhaust gas, to combust carbonmonoxide contained in the exhaust gas to form combustionexhaust gas; and selectively directing part of the combustionexhaust gas into at least one scrap preheating chamberprovided along a branch duct branching off from the dischargeduct to preheat steel scrap charged in the scrap preheatingchamber to a predetermined temperature. The method beingcharacterized by: feeding back all of the combustionexhaust gas after preheating the steel scrap charged in thescrap preheating chamber to the exhaust gas combustion chamberto combust any incomplete-combustion products which areproduced by the incomplete combustion of combustible sub-stances entrapped in the steel scrap and which are containedin the combustion exhaust gas. The method has the advantageof reducing pollution. A method of controlling the preheatingof the steel scrap at a constant level irrespective ofvariations in the temperature of the combustion exhaust gasis also taught.