| 摘要 |
PURPOSE:To extend the life of a torch and to perform economically titled degassing by providing a plasma arc heating chamber adjacently to a riser for a molten steel and admitting the working gas for plasma arc into the bottom end part of said riser. CONSTITUTION:A reflux type vacuum degassing device 3 constituted of a vacuum vessel 4, a riser 5 and a downcomer 6 is provided in a ladle 1, and a heating chamber 8 of a plasma arc heater 7 is positioned adjacently to the riser 5. An electrode 9 for generating plasma arc is provided atop the chamber 8 toward the molten steel 2 and working gas such as gaseous Ar is supplied from the outside circumference of the torch. Then, the working gas used in the stage of plasma arc heating emerges from an aperture 10 and enters the inside of the riser 5 to accelerate the rise of the molten steel 2 in the riser 5, thereby performing economically vacuum degassing. |
