Physical characteristics of gas jets injected vertically upward into liquid metal

The time-averaged structure of plumes has been measured with a two-element electroresistivity probe during upward injection of nitrogen or helium into mercury in a ladle-shaped vessel. From these measurements and data obtained earlier for air jets in water, general correlations linking the spatial distribution of gas fraction with the Froude number and gas/liquid density ratio have been developed. Early evidence suggests that these correlations should be applicable to gas-stirred metallurgical baths. Measurements of the profiles of bubble velocity and bubble pierced length reveal that the kinetic energy of the gas is dissipated close to the nozzle, and buoyancy dominates flow over most of the plume.