Heat Transfer between Bubbles and Molten Wood's Metal.

Abstract

In refining processes for steel and some other metals, gas is blown into molten metal from the top, the bottom or simultaneously from the top and bottom of the vessel to promote mixing and chemical reactions. Since the gas is usually injected at a temperature lower than the molten metal temperature, knowledge about the heat transfer between gas and molten metal is required to predict preciseiy the mixing effect. Present authors previously carried out cold model experiments for bottom injection to investigate the mechanism of convective heat transfer betweenbubbles and liquid, using cooled gas andwater and proposed an empirical correlation for the Nusselt number. In this paper, the mechanism of convective heat transfer betweenbubbles and molten metal was investigated using molten Wood's metal. Thefunctional relationship between the Nusselt numberand the Peclet number was the same as that for water models although the Prandtl numbers of water and Wood'smetal were much different with each other.