A turbulent fluid flow model of gas agitated reactors

Abstract

A general, time independent, turbulent fluid flow model is developed to predict the gas dispersion and recirculating flowfields inside gas agitated reactors. The gas/liquid mixture is treated as a continuous fluid of variable density, and the dispersion of the gas is described by a turbulent diffusion equation in conjunction with a simple ad hoc effective viscosity formula. The model is applied to the three main submerged injection configurations encountered in the metallurgical industry. For the two cases of injection vertically upwards through the base of a reactor, and vertically downwards through a submerged lance, the model predictions are in semi-quantitative agreement with experiment and the model provides a useful means of calculating the gas concentration distribution over a wide range of flowrates. The limitations of the above approach are discussed in the context of horizontal injection and a more comprehensive model to overcome the current constraints is highlighted.