METAL MELTING FURNACE UTILIZING BOTH VACUUM DEGASSING AND BUBBLING ACTIONS

摘要

PURPOSE:To promote degassing of molten metals by air permeation and clarifying gas bubbles in the melt, wherein means for introducing innert gas from lower part of the furnace is provided together with lowering the pressure of the furnace. CONSTITUTION:In a molten metal bath 1, vacuum degassing is conducted using pipe 5 of vacuum suction pump system to reduce the inside pressure of the furnace. Clarifying by degassing is made by ejecting such innert gas as N2 from a refractory pipe end 3 positioned near the bottom of the furnace to which N2 gas for bubbling is introduced through the pipe 6. By this means, small sized gas bubbles entrapped in the melt are allowed to move to get together and to form large sized bubbles to come-up to the surface of the melt. Thus, acceleration of degassing is achieved with the synergistic effects of both vacuum degassing and bubbling.