Model study of fluid flow phenomena in a bottom blown bath in the presence of reverse emulsification

Model experiments were carried out to elucidate the behavior of rising bubbles and resultant liquid flow motion in a cylindrical bath agitated by central bottom gas injection. Emphasis was placed on the bubble and liquid flow characteristics in the presence of reverse emulsification, i.e., the slag droplet formation in the lower metal layer. Silicone oil and n-pentane were used as models for top slag and water was used as a model for molten metal. A thin top oily liquid layer was placed on a pool of water. Air was injected through a central single-hole bottom nozzle. The bubble and liquid flow characteristics for the top silicone oil layer were modulated significantly from their respective characteristics in a water bath without a top oil layer. On the other hand, these two characteristics for the n-pentane layer were not influenced by the top oil layer at all inspite of the occurrence of the reverse emulsification. The difference of the bubble and liquid flow characteristics between the silicone oil and n-pentane layers can be explained by the fact that the fluid flow resistance at the silicone oil/water interface is much larger than that between the n-pentane/water interface.