Yojukinzokunokyuyo * toshutsuhanpukunyorukakuhanseirenniokerukyuyoseigyohoho

摘要

PURPOSE:To effectively inhibit the formation of splashes inside a tubular refractory material, by gradually raising the speed of changing internal pressure inside the tubular refractory material in the step of sucking-up molten metal from the starting point toward the terminal of said step to control the sucking- up. CONSTITUTION:In agitatively refining molten metal 3 in a refining vessel by immersing the lower end of a tubular refractory material 1 into said molten metal 3 and alternately repeating evacuation, and pressurization to repeat sucking-up and vomitting, a plurality of switch valves #1, 2, 3, 4... n parallelly connected to an exhaust system are provided between the top part of the tubular refractory material 1 and an evacuating pump 2. Driving commands 5 are dispatched in response to the output of a detector 6 for detecting internal pressure inside the tubular refractory material 1 by a computer 7 to sequentially open the switch valves #1, 2, 3, 4... n in order to gradually raise the speed of changing the internal pressure with the advance from the starting point to the terminal of the sucking-up. Thus, there exists no possibility of a functional disorder in the evacuating and pressurizing systems.