Experimental Investigation of Power Consumption, Mass Transfer Coefficient and Flow Regime in Gas-Liquid Dispersion Systems

Gas liquid dispersion technology is a major part of the infrastructure of chemical, petrochemical and biochemical industries. Flooding is one of the characteristic features of stirred tank equipment used to disperse gases in liquids. Most investigators have studied the flow regime and mass transfer coefficient relying solely on the Rushton turbine. However, there are cases wherein the utilization of an inappropriate type of impeller results in both waste of energy and marked counter-productivity. Hence, the objective of this paper is to examine the performance of gas-liquid dispersion systems interms of flow regime, mass transfer coefficient and the loading zone for the gassed condition using the Rushton turbine, pitched blade, concave blade and the vaned disc type impellers. For the gassed conditions, we concluded that the vaned type disc gives the optimal mass transfer coefficient. We have also examined the hysteresis phenomena for the Rushton turbine and established a new flow region called transition, in which both the loading and flooding zone is present.