METHOD OF MELT TREATMENT IN LADLE WITH VARYING POSITION OF LANCE Russian patent published in 1998 - IPC

FIELD: metallurgy; melt treatment in ladle with varying position of lance. SUBSTANCE: in the course of main period of melt blowing in ladle with inert gas, lance position is varied in time, for instance, by saw-tooth law. Information on pressure before lance is smoothed and reduced to the limit lower position of lance. Continuously sought on obtained relationship curve is absolute minimum and information characteristics Δ₁(t)-Δ₄(t), are determined. They indicate the actual lance section narrowing due to metal deposition and lance shortening. At low values of information characteristics blowing conditions are realized at the preset level. In case of considerable and slow shortening of lance, blowing is changed to the limit lower position. With further shortening of lance or considerable and slow narrowing of lance due to metal deposit, blowing time is increased in function of narrowing or shortening of lance. In case of intolerable narrowing or shortening of lance, blowing is to be discontinued and lance to be lifted. EFFECT: efficient treatment of melt in ladle due to position varying of lance during blowing, consideration of lance condition and improved quality of melt treatment. 2 dwg