Hydrodynamic Comparative Study on the Pumping Effects of a Square Tank Equipped with Single-Stage and Bi-Stage Impellers

A computational fluid dynamics simulation is done for comparative study from the pumping effect on the four surfaces of the stirred tank. The flow field generated by one-stage and bi-stage six-bladed Rushton turbine in the unbaffled square tank was studied. The Reynolds-averaged Navier-Stokes equation with steady-state multi-reference frame approach (MRF) is used to simulate hydrodynamic flow in the tank. The turbulent viscosity, the turbulent kinetic energy and mean velocity distributions obtained in vertical and horizontal plans are analyzed and discussed. We can deduce that the additional Rushton turbine in the upper part of the square tank improves the quality of the mixture.