CIRCULATION RATE OF LIQUID STEEL IN RH DEGASSERS

Vacuum-decarburization with the Ruhrstahl-Heraeus process is used for the production of ultra-low carbon steels. One important aspect of the RH process is the circulation of liquid steel between the degassing u nit and the transport ladle. Thus, supervisory control of the RH treat ment requires precise mathematical modelling of the circulation rate, in this work, a numerical model of the circulation flow is described i n detail. This newly developed model as well as a frequently used semi -empirical equation are compared with measured data. It is shown that the numerical model is in far better accordance with the measured data than the semi-empirical equation. The numerical model is then applied to data of a conventional RH treatment. Special emphasis is put on th e coupling of circulation rate and reaction rate. Both, circulation ra te and reaction rate, are calculated as a function of time.