| 摘要 |
PROBLEM TO BE SOLVED: To facilitate tapping of a molten metal from a copper crucible of an incompletely floating melting apparatus by providing a bottom hole at a bottom of the crucible, and providing a mechanically and electrically integral bottom cover at the hole. SOLUTION: An eddy current is induced at a bottom cover 4 by means of a magnetic flux tending to invade a bottom of a molten metal 1a through the cover 4, a magnetic flux of reverse direction to that of the magnetic flux tending to invade the cover 4 is induced, and the fluxes cancel to one another to be magnetically shielded. Accordingly, no eddy current is induced at the bottom of the metal 1a, and no floating force is generated as well. Accordingly, the bottom of the molten metal 1a is brought into contact with a side cover 4, and cooled to form a solidified layer 1c. Therefore, the layer 1c becomes a reception tray of the metal 1a, and the other molten metal is melted in an incompletely floating state to become a non-contact state with a copper crucible 1. Thus, since the bottom cover of the crucible is removed so that the molten metal can be output, a unit for inclining the crucible or an induction coil or a unit for withdrawing the molten metal in vacuum is unnecessarily eliminated.
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