Pulsed field induction heating for metals - using rotating DC coils or rotating yoke element to vary magnetic circuit reluctance

摘要

The metal object (1) to be heated has an overall flat form positioned across the poles of two DC coils (3,4) forming a series magnetic circuit via the metal and a 'U' shaped yoke (2). The coil arrangement spins about its centre line (5) over the metal and a pair of fixed low reluctance magnetic material elements. The field in the metal varies as a function of rotation of the coil group. Alternatively the two coils may be fixed, the field variation being due to rotation of an inter-connecting yoke element. The method overcomes the poor power factor achieved in orthodox continuous systems.