| 摘要 |
PURPOSE:To prevent molten metal from splashing by providing a porous plate for a cracker which can be energized to the emitting portion of a vapor metal. CONSTITUTION:A cracker 7 which is formed by laminating three porous plates 11 made of high purity carbon plates detachably mounted in contact in high density is provided in the neck of a PBN crucible. When an energizing tantalum ribbon 8 is clamped with screws 9 to the cracker and a current flows to the ribbon, it is heated to operate as a heater. A temperature control thermocoupler 10 is mounted at the heater 7 to control the temperature of the heater, and vapor metal and splash from the melted raw metal 12 are fed through the pores of the first porous plate of the heater 7 to the pores of the second porous plate. The pores of the second plate are displaced from the geometrical positions of the pores of the first plate, and do not arrive directly at the final porous plate to which the metal vapor is directly injected to the exterior. Specially, the splashed small melted metal lumps are vaporized here.
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