| 摘要 |
PROBLEM TO BE SOLVED: To expand the controllable range of a tapping amount per unit time, and reduce the rising and trailing intervals at the times of a tapping start and a completion by providing a bulkhead section which divides a vacuum tank into the top and the bottom, above the tapping port of a metal crucible, and performing air dischargings for respective top and bottom vacuum tanks by individual vacuum air discharging systems. SOLUTION: Both top and bottom vacuum tanks 10 and 12 in which a cooling type metal crucible 1 is fitted, are partitioned into the top and the bottom with the side surface of a partition jacket 11 attached to the lower end of the metal crucible 1 as a border, and the top and bottom vacuum tanks 10 and 12 are vacuumized by respective vacuum air discharging systems 13 and 14 which are respectively individually arranged. Then, in the metal crucible 1, a material to be molten is charged in advance, and current is fed to induction coils 3 and 4 from respective AC power sources 5 and 6, and respective eddy currents 8 and 9 are induced in the metal crucible 1, and thus, the material to be molten is heated, and at the same time, an electromagnetic force is generated. By imparting a floating force to the material to be molten with the electromagnetic force as a repulsion force, the material to be molten is molten and made into a floated molten metal 1a.
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