Prediction of temperature in secondary steelmaking: mathematical modellingof fluid flow and heat transfer in gas purged ladle

As a first step towards prediction of temperatures in secondary steelmaking , mathematical modelling of fluid flow and heat transfer in ladle furnace w as undertaken. A two-dimensional quasi-single phase model has been develope d for turbulent recirculating flow by solving Reynolds averaged Navier-Stok es equations along with a two-equation k-epsilon model. The model was then extended to include thermal transport in a conjugate domain (i.e., molten s teel + refractory shell + steel shell). The flow model was validated with w ater model data reported in literature by different researchers. Good agree ment for velocity field and satisfactory agreement for turbulent kinetic en ergy field were obtained. The thermal model showed good agreement with resu lts predicted in literature. The paper also presents findings of tests for sensitivity of flow on modell ing and process parameters. By comparison with water model experiments, it has been demonstrated that the flow field in a ladle with a porous plug can be represented using a gas voidage fraction in the plume: obtained from ex periments with nozzles for axial gas injection from the bottom. Flow and th ermal fields were insensitive to initial turbulence level at nozzle. Maximu m temperature inhomogeneity in the melt was 2 degreesC after 1.5 min and ne gligible after 3 min of onset of gas purging.