Induction furnace providing controlled escape of superheated metal

摘要

An induction furnace which provides a controlled escape pathway for superheated metal is disclosed. The induction furnace comprises a base layer of refractory material in the bottom of the furnace vessel. The base layer of refractory is composed of a first refractory having a maximum operational temperature and a second refractory having a maximum operational temperature lower than that of the first refractory. At least a portion of the second refractory is arranged in a contiguous zone through the thickness of the base layer. The base layer supports a packed granular refractory lining that extends up along the side wall of the vessel. In one embodiment of the invention, the base layer takes the form of a means for pushing out the packed granular lining from the furnace. The pusher means is arranged for axial movement within the furnace in response to a driving force applied from below the base layer. The pusher means contains the contiguous zone of the second refractory. In another embodiment of the invention, the base layer is comprised of tiers of refractory, each tier comprising a portion of the second refractory in the same location as in each other tier forming a contiguous zone of the second material. The failure of the second refractory zone allows the superheated metal to escape through the base of the furnace in a controlled manner at the preselected location of the second zone.