Eddy current calculations in a segmented cold crucible

F. R. Block - K. Gailitis - K. Hoffer

University of Technology Aachen, Germany

Abstract
Experimental results reported in the literature show that in cold crucibles instabilities occur on the surface of the charge. In order to investigate the fundamental background of this phenomena, eddy current and electromagnetic force distributions have been calculated in a cylindrical, segmented copper crucible containing an electrically conducting charge. The calculations show, that eddy current and electromagnetic force distributions in the charge vary strongly with the azimuth and that local eddy current whirls occur near the insulating gaps. This explains the instabilities. The construction of cold crucibles can be optimized using computer-aided electromagnetic field calculations. Figs 9, Ref. 1.