Patent ID: 7197061
Filing Date: 2007-03-27
Classification: C30B,F27B,F27D

Abstract:
1. An apparatus for directional solidification of a metal comprising: a vessel for containing a molten mass of the metal; a plurality of induction coils surrounding the height of the exterior of the vessel; a switching means for each of the plurality of induction coils, each of the switching means having a first switch terminal and a second switch terminal, each of the first switch terminals exclusively connected to a first coil terminal of each of the plurality of induction coils; a single source of ac current having a first source terminal and a second source terminal, the first source terminal connected to all of the second switch terminals, the second source terminal connected to all of the second coil terminals; and a control means for selectively opening and closing each of the switching means to progressively decrease the induced heat from the bottom to the top of the molten mass of the metal in the vessel.