Temperature distribution in aluminium billets heated by rotation in static magnetic field produced by superconducting magnets

The efficiency of conventional induction heaters used in industrial processing of metals approaches 100% when materials with high magnetic permeability are concerned, whereas it reduces to about 50-60% when non magnetic metals such as aluminum or copper are considered. In order to improve the efficiency, a novel scheme of induction heater for non magnetic metal billets has been recently proposed. The idea is to force the billet to rotate the in a static magnetic field produced by a DC superconducting magnet, thus converting in thermal power all the supplied mechanical power. Since a static superconducting magnet has no losses, the efficiency of such a system coincides with the efficiency of the motor used, which for large powers is beyond 90%. In this paper the feasibility of such an heater is numerically investigated.