Abstract
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 center line value and half-value radius of gas holdup were given by empirical correlations. The ratio of half-value radius of gas holdup to that of liquid velocity was also given by empirical one. 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 the inertia force of injected gas prevails and the gas holdup on the center line, αCl, is higher than about 10%, it is hard to define which model is more adequate, but in the region far from the nozzle where αCl is lower than about 10% as a result of very high turbulent mixing, the slip flow model would be better.
