Heat flow sensing system for an induction furnace

Abstract

An induction melting furnace includes a detection system for sensing metal penetration into a wall of the furnace depending upon detecting heat flow from the hearth to the furnace. The furnace includes a crucible including a refractory lining for holding molten metal, a coil for inductively heating the molten metal, and a power supply for supplying energy to the coil and the detection system. An electrode system is interposed between the coil and the lining comprising a sensing mat housing conductors receiving a test signal from the power supply, wherein the sensing mat includes a temperature sensitive binder that varies conductivity between the conductors in response to heat penetration through the lining. The sensing mat is preferably comprised of flexible phillosilicate mica for enhanced thermal conduction and the binder comprises an organic resin compound which carburizes at a predetermined elevated temperature.

Dependencies are inferred from the claim text.