procedures for the operation of coreless induktionsschmelz and / or holding furnaces and appropriate electrical schalteinheit

摘要

PCT No. PCT/DE95/00175 Sec. 371 Date Oct. 7, 1996 Sec. 102(e) Date Oct. 7, 1996 PCT Filed Feb. 10, 1995 PCT Pub. No. WO95/22238 PCT Pub. Date Aug. 17, 1995In a process for the operation of coreless induction melting and/or holding furnaces-in which there results in the melting operation at a relatively high induction frequency (as compared to the mains frequency) a slight stirring motion in the melt, but a high degree of effectiveness for the melting process, and in the melting and holding operation at a correspondingly lower induction frequency there results a greater stirring motion in the melt, but a lower degree of effectiveness for the melting process-it is provided that at least one capacitor switched in parallel to the induction coil(s) is provided, which capacitor(s), together with the induction coil(s), form a resonant circuit; and that in the transition from the melting operation with slight stirring motion in the melt to the melting or holding operation with greater stirring motion, or in the reverse transition, the capacitor capacitance and/or the inductance present in the resonant circuit is increased, or as the case may be, decreased.