APPARATUS AND METHOD FOR SUPPLYING COVERING GAS FOR MOLTEN METAL

摘要

PROBLEM TO BE SOLVED: To provide a apparatus for supplying covering gas for molten metal by which fluctuations in the concentration of effective components in the covering gas for molten metal can be suppressed. SOLUTION: This covering gas supplying apparatus has: a filling vessel 1 to be filled with a molten metal treating agent composed of a liquid mixture containing liquefied carbon dioxide and fluoroketone; a vaporizer 2 for vaporizing the molten metal treating agent to prepare vaporized gas; a vaporized gas pressure regulator 3 for keeping the pressure of the vaporized gas nearly constant; a vaporized gas flow regulating valve 4 for regulating the flow rate of the vaporized gas; a base gas supply part 5 to be a base gas supply source; a base gas pressure regulator 6 for keeping the pressure of the base gas nearly constant; a concentration detecting means 8 for detecting the fluoroketone concentration in the covering gas prepared by mixing the vaporized gas and the base gas; and a control part 11 for controlling the flow rate of the vaporized gas by regulating the opening of the vaporized gas flow regulating valve 4 on the basis of the detected value of the concentration detecting means 8. COPYRIGHT: (C)2005,JPO&NCIPI