1994 Volume 34 Issue 4 Pages 322-329
A mathematical model for estimating liquid and bubble rising velocities in metallurgical reactors subject to bottom gas injection was proposed. The mass conservation of gas and the momentum conservations of gas and liquid were employed as governing equations. Radial profiles of gas holdup and liquid velocity were assumed to be Gaussian distribution. Axial distributions of the center line value and the half-value radius of gas holdup were given by empirical correlations. The ratio of the half-value radius of gas holdup to that of liquid velocity was also given by empirical correlation. The slip flow model and the drift flux model were employed for estimating bubble rising velocity. Concerning the liquid velocity, the results of this study agreed well with experimental results published so far. For the bubble rising velocity, in the region near the nozzle where gas holdup on the center line, αc/l, is higher than about 10%, it is hard to define which model is more appropriate, but in the region far from the nozzle where αc/l is lower than about 10% as a result of very highly turbulent mixing, the slip flow model would be better.