Simulation of flows in stirred vessels agitated by dual rushton impellers using computational snapshot approach

Abstract

Flow in baffled stirred vessels involves interactions between flow around rotating impeller blades and stationary baffles. When more than one impeller is used (which is quite common in practice), the flow complexity is greatly increased, especially when there is an interaction between two impellers. The extent of interaction depends on relative distances between the two impellers and clearance from the vessel bottom. In this paper we have simulated flow generated by two Rushton (disc) impellers. A computational snapshot approach was used to simulate single-phase flow experiments carried out by Rutherford et al. (1996). The computational model was mapped on the commercial CFD code FLUENT (Fluent Inc., USA). The simulated results were analyzed in detail to understand flow around impellers and interaction between impellers. The model predictions were verified using the data of Rutherford et al. (1996). The results presented in this paper have significant implications for applications of computational fluid mixing tools for designing multiple impeller stirred reactors.