Method and apparatus for preheating and feeding material

Abstract

A casting furnace for preheating and melting solid feed material includes a melting chamber with a melting hearth therein and a feed chamber in fluid communication with the melting chamber for conveying the solid material into the melting chamber. A heat source melts the feed material within the melting hearth and produces surplus heat used to preheat the solid feed material. Preferably, gas is heated by the heat source and moved into the feed chamber to preheat the feed material while it is conveyed toward the melting hearth. The heated gas is recycled back into the melting chamber to be re-heated therein and reused to preheat additional feed material in the feed chamber. Where the heat source in the melting chamber includes a plasma torch, the gas is recycled via the plasma torch, which ionizes the gas to create a plasma plume for melting the solid material.

Dependencies are inferred from the claim text.