Dual surface heaters

摘要

A dual plate heater provides two parallel temperature self-regulating heater plates or wire mesh comprising ferromagnetic material with one or more electrically energized coils parallel to and located between the heater plates which coil(s) when energized by a constant current or by an otherwise controlled current heat the plates to their Curie temperature or temperatures. The coil may be a flat spiral of thin conductive (copper) wire embedded in a thin layer of a heat conductive, electrically non-conductive material between said plates whereby heat energy generated in the coil is supplied to the heater plates. The dual plate heater may be employed to heat plastic pipes to their butt welding temperatures after which the heater is removed to the ends of the pipes to be joined are brought into contact under pressure. The dual plate heaters may also be employed in other arrangements such as shelves in a dispensing machine.