Abstract: An electric arc melting furnace includes a furnace shell (1) with an electrode (3) for melting scrap by heat of arc, an air blasting port (20) for blasting air, oxygen or oxygen-enriched air into the furnace shell (1) through an air control valve (19), a carbon blasted quantity indicator (CI) for measuring quantity of carbon to be charged into the furnace shell (1), a scrap charged quantity indicator (SI) for measuring quantity of the scrap charged into the furnace shell (1), an oxygen blasted quantity indicator (OI) for measuring quantity of oxygen blasted into the furnace shell (1) and an arithmetic processor (7) for computing quantity of air required for complete combustion of carbon monoxide (23) in the furnace shell (1) in response to measured value from the indicators (CI)(SI)(OI) to control a degree of opening of the air control valve (19).

Abstract: An electric arc melting furnace comprises a furnace shell (1) with an electrode (3) for melting scrap by heat of arc, an air blasting port (20) for blasting air, oxygen or oxygen-enriched air into the furnace shell (1) through an air control valve (19), a carbon blasted quantity indicator (CI) for measuring quantity of carbon to be charged into the furnace shell (1), a scrap charged quantity indicator (SI) for measuring quantity of the scrap charged into the furnace shell (1), an oxygen blasted quantity indicator (OI) for measuring quantity of oxygen blasted into the furnace shell (1) and an arithmetic processor (7) for computing quantity of air required for complete combustion of carbon monoxide (23) in the furnace shell (1) in response to measured value from the indicators (CI)(SI)(OI) to control a degree of opening of the air control valve (19).

Abstract: An apparatus for preheating and charging scrap material includes a throat section (38) having at one end thereof a material charging inlet (37) connected to a furnace shell (2), the throat section extending laterally and upwardly obliquely, a heat exchanger section (39) connected to the other end of the throat section (38) and extending upwardly, a sealing section (42) above the heat exchanger section (39), a material supply (43) for supplying the scrap material into the sealing section (42), an exhaust duct (53) formed at the heat exchanger section (39) just below the sealing section (42) and connected to an exhaust system (58) and a material delivery device (46) disposed at the other end of the throat section (38) for delivering the scrap material (13) from the heat exchanger section (39) to the material charging inlet (37). The scrap material (13) is substantially continuously charged into the furnace shell (2) while preheated by the high-temperature exhaust gases from the furnace shell (2).