Power Number Correlation between Newtonian and Non-Newtonian Fluids in a Mixing Vessel.

Abstract

The power consumed by the Rushton and 60° pitch-blade impellers with Newtonian fluids and CMC shear thinning solutions have been obtained as a function of impeller rotational speed. The Power number with the Rushton impeller increased gradually with Reynolds number while it remained almost the same with the 60° pitched blade impeller with a sudden drop in power at a point where the discharge flow change from a radial flow to an axial one. A good correlation between the power numbers of the Newtonian fluid and CMC solutions in turbulent flow have been obtained with both impellers, in particular with the Rushton impeller, when a shearing constant of 54 was used. With the 60° pitch-blade impeller, the CMC solution had the effect of delaying the flow transition to a higher Reynolds number with higher concentration causing more of a delay.