Mixing phenomena inside the ladle during RH decarburization of steel melts

The RH (Rheinstahl-Heraeus) process is in widespread use to produce ultra-low carbon steel by vacuum treatment. Among other factors, the decarburization rate is effected by mixing phenomena inside the ladle. Thus, supervisory control of the RH treatment requires an adequate and precise representation of the mixing conditions. In this work, mixing is characterised by concepts of chemical reaction engineering. Different sizes and geometries of RH installations are taken into account using similarity criteria. A simple model is derived from the experimental results and detailed numerical flow computations. For this model, a mathematical function of mixing is developed which can be incorporated into supervisory control systems.