Abstract

Furnaces, Electric, Arc Furnaces. J. Kevin Cotchen (MAN GHH Corp.). Arc furnaces used in electric melting, smelting, and electrochemical operations are of two basic designs; indirect and direct arc. The arc of the indirect-arc furnace is maintained between two electrodes and radiates heat to the charge. The arcs of the direct-arc furnace are maintained between the charge and the electrodes, making the charge a part of the electrical power circuit. Not only is heat radiated to the charge, but the charge is heated directly by the arc and the current passing through the charge.

Indirect-arc furnaces have been used primarily in foundries for melting copper, copper alloys, and other nonferrous metals that have a low melting point. Direct-arc furnaces include open-arc furnaces, d-c arc furnaces; submerged arc-furnaces; and arc-resistance furnaces. All new furnace installations require pollution control equipment. This normally consists of off-gas afterburning (sometimes with energy recovery), and dust collection equipment, typically a baghouse.