Characteristics of Circulating Liquid in Bottom-blown Refining Vessel

Abstract

The recirculating flow rate of liquid in a ladle is one of the dominating factors for the mass transfer in bottom-blown refining vessel.
A mathematical model for predicting the recirculating flow rate of liquid in bottom-blown ladle is developed on the basis of the mass and momentum balances. In order to evaluate the recirculating flow rate, the recirculating time of a tracer particle was measured in the water model experiments. The recirculating flow rate obtained in the water model experiments is well predicted by the mathematical model.
On the basis of the mathematical model and the experiments, the following results regarding the recirculating flow rate were observed: (1) it increases with increase of liquid depth under the same amount of mixing power density, (2) it decreases with increase of vessel size of geometrical similarity, (3) it decreases when gas is injected at eccentric position, (4) the product of the mixing time and the recirculating flow rate in given vessels is nearly constant over the wide range of mixing power density.