When gas is bubbled through a molten metal, overlying slag is pushed to the side forming an open ''eye'' of exposed metal. Eye sizes were measured in room-temperature modeling over a wide range of conditions including the fluids to simulate slag and metal, gas flow rates, and depths of both fluids. A mechanistic model for eye size was developed from fundamental fluid flow considerations. The model expresses a dimensionless eye area in terms of a density ratio of the fluids and a Froude number. The model is consistent with the present experimental results and those of others in different liquid systems. Finally, previously published correlations for eye size have been critically evaluated.

The behavior of metal droplets in a slag-metal-gas emulsion through impinging gas blowing was investigated experimentally using a cast iron-slag-nitrogen gas system at high temperatures. A mathematical model of the emulsification process for determining the generation rate, size distribution, and residence time of metal droplets has been developed and successfully validated using experimental data. From the present work, it was found that the generation rate and size distribution of metal droplets is strongly influenced by the ratio of the inertial force of blown gas to the surface tension and buoyancy forces of the liquid metal. A new dimensionless number, i.e. blowing number, which represents the ratio of inertial to surface tension and buoyancy forces and also the departure of the system from its stable condition defined by the Kelvin-Helmholtz criterion, is proposed. A functional relationship of generation rate and size distribution of metal droplets with the blowing number is proposed.KEY WORDS: droplet generation; droplet size distribution; residence time; impinging gas blowing; slagmetal emulsion; steelmaking.

In ladle metallurgical operations, it is common practice to use an inert gas for stirring. The stirring is used to achieve homogenization and to pursue chemical and physical changes. The raised region where the gas discharges from the bath during argon stirring is usually called a spout.Where the spout is uncovered by slag, the region is called the spout eye.1) The spout region is significance in industrial practice, since it is an important site for slag-metal reactions and the site of undesirable reactions between metal and air. However, there has been relatively little study to elucidate the phenomena.Recently, Yonezawa and Schwerdtfeger 1,2) reported a comprehensive investigation of the spout region. They studied the phenomena with the objectives to determine the dimensions of the spout and the spout eye. Data were obtained from cold model experiments, by using mercury and silicon oil for simulating metal and slag, respectively, and plant measurements on a 350 t ladle. A video camera was employed to measure the spout formation and spout eye area. For measuring the height of the spout, electroresistivity probes were used for the cold model and the dissolved tube length technique for the plant measurements. The results indicated that spout eye formation and spout eye size are highly dynamic, as a consequence of the discontinuous gas discharge at the nozzle and of the subsequent disintegration into bubbles.Despite their success in measuring spout eyes, both in the cold model experiments and plant trials, they failed to develop an adequate functional correlation between eye area, A es , and operational variables. By employing dimensional analysis technique,