Continuous melt electric furnace with continuous discharge

摘要

An electric melting furnace is provided with an exit comprising an overflow dam and a downwardly extending unmolten-substances blocking plate placed inwardly of the overflow dam. The exit is positioned on or near an extension of a line connecting the center O of a furnace body and one of the furnace electrodes, the distance L in centimeters between the electrode and the overflow dam being determined by the equation: <IMAGE> where P is the electric furnace load (w) and K is a constant in the range of 16 to 25. Lighter molten substances are continuously discharged over the dam under the weight of the combustion residue. Heavier molten metals accumulate on the furnace floor and are discharged over dam by tilting the furnace body in the direction of the exit. The furnace has a measuring means placed at an upper interior portion of the furnace for measuring the temperature of the furnace gases and another measuring means placed on the discharge passage for measuring the quantity of the luminous energy radiated by the molten substances. The values obtained by the temperature measuring means and the luminous energy measuring means are compared with respective standard values as set in advance to determine the feeding of the combustion residue. When one or both of the feeding conditions is/are met, a fixed amount of the combustion residue is fed into the furnace by opening a feeding gate.