Water model experiments on mixing phenomena in a VOD ladle

Mixing phenomena in a VOD ladle were characterized by a watermodel simulati on from the determination of mixing times by electrical conductivity measur ements. Two mixing times defined for two degrees of mixing, viz., t(95) (95 % mixing) and t(99) (99% mixing) were identified for each experiment. Vario us operating conditions as well as different placements of bottom nozzle wi th and without a top jet were simulated. irrespective of whether the top bl ow is present or not, mixing rates were found to be increasing considerably as the nozzle position is moved from the center to the mid-radius position . The presence of a top jet, as in a VOD ladle, was found to weaken mixing for both a coaxial and non coaxial placement of the lance with the bubble p lume. The results of watermodel experiments have been used to construct a s imple two-tank model of mixing inside the actual ladle, in which the parame ters are obtained as functions of process variables.