Fluid flow and mixing characteristics in RH degasser of Companhia Siderúrgica de Tubarão, and influence of bottom gas injection and nozzle blockage through physical modelling study. - da Silva, C. A.; da Silva, I. A.; de Castro Martins, E. M.; V. Seshadri; Perim, C. A.; Filho, G. A. Vargas (Ironmaking & Steelmaking, 2004)