Apparatus having gas-actuated pump and charge well and method of melting

Abstract

The charge well of a metal melting furnace is provided with an internal cavity having a circular cross section when viewed from the top, preferably a cavity of cylindrical or conical configuration, and with a peripheral exit port located tangentially with respect to said cavity at a lower level thereof for exit of molten metal into the main chamber of the furnace. An inert gas bubble-actuated molten metal pump brings molten metal from a hotter section of the furnace, advantageously directly from the main chamber, and has its exit port located tangentially to the periphery of the cavity at an upper level thereof, thereby creating vortical flow of molten metal within the charge well for the more rapid and efficient melting of metal chips and scraps into the molten metal therein and for circulation of hotter molten metal throughout the furnace. A head of molten metal can be created in the charge well, which advantageously has an exit port of restricted internal cross-sectional area, to assist with attainment of these objectives. A heat and flame-resistant cover may be located above the cavity and advantageously has an aperture therein for the loading of metal chips or scrap thereinto. A gravity-feed chip charger may surmount the aperture for the discharge of new metal chips or scrap into the cavity through the said aperture.