Experimental and Numerical Analysis of Power Consumption for Mixing of High Viscosity Fluids with a Co-Axial Mixer

An experimental and numerical programme has been carried out to explore and determine design and mixing performance characteristics of co-axial agitation systems. Power consumption analyses in Newtonian and non-Newtonian fluids in laminar regime for a co-axial mixer configuration for chemical processes are discussed. An anchor impeller was used in combination with a dual set of pitched blade turbines in co-rotating mode. It was demonstrated that the power consumption of the proximity impeller is affected by the tip speed ratio, but no influence of the proximity impeller speed on the power drawn by the pitched blade turbines was observed. Computational fluid dynamics (CFD) was employed to calculate the flow field created by the co-axial mixer. CFD was able to predict well the power consumption of the co-axial mixing system. Power and Reynolds number were adapted to obtain the power characteristics of co-axial mixers. The approach employed to obtain a single master power curve succeeded for the investigated co-axial mixer configuration and is a useful engineering tool to predict the power consumption of co-axial mixing systems.