Abstract
In order to investigate the decarburization behavior in the 250 ton RH degassing unit, effect of [C], [O] and pressure in vacuum vessel, P, on apparent rate constant of decarburization, Kc, was studied based on CO bubble formation model.
1) Kc showed lower value in the initial and final stage of decarburization process and higher value in the middle stage. Low Kc in the initial stage was supposed to be due to low circulation rate, Q, and low Kc in the final stage was supposed to be due to low CO bubble formation rate.
2) Volmetric mass transfer coefficient for decarburization, ak, and Kc in the middle and final stage showed a good correlation with [C]·[O]. This relation could be derived from CO bubble formation model.
3) Pressure in the vacuum vessel had an effect on Q in the initial stage. Calculated Q with empirical equation coincided with the value of commercial RH obtained using observed Kc and estimated ak.
4) A new decarburization model for RH was constructed. Calculated results showed a good agreement with observed [C]. And effect of exausting rate on Kc could be evaluated with this model.
