Design and MHD (Magnetohydrodynamics) Stability for Horizontal Electromagnetic Continuous Casting

摘要

High-frequency electromagnetic (EM) fields are proposed for the continuous casting of thin sheets of metal in a horizontal orientation. Major EM components of the caster include a picture- frame magnet, conducting side guards for positioning and side containment, and an eddy current return path that requires an electrode near the inlet and pickup brushes or roller near the outlet of the caster. An inductance stabilization method provides global stability, and magnetic flux compression provides local stability. Stability analysis and EM heating constraints indicate that frequencies in the range of 25-100 kHz are desirable to levitate 6-mm-thick steel. For systems without active feedback, a conducting screen is required below the metal with a gap between the screen and the molten metal no more than twice the metal thickness. Experiments using 10-kHz EM fields to statically levitate sheets of molten tin indicate that dominant MHD instabilities correspond to theory. 23 refs., 3 figs. (ERA citation 14:000876)