Liquid-phase mixing in an unbaffled agitated vessel with an unsteady forward-reverse rotating impeller

For an unbaffled agitated vessel with an unsteady forward-reverse rotating impeller, whose rotation reverses its direction with a constant angular displacement, the progress of liquid-phase mixing was studied experimentally in relation to the characteristics of the liquid flow produced by the impeller. The forward-reverse rotating disk turbine impeller with six flat blades has about 1.5 times the shear level of a unidirectionally rotating impeller of identical design. The turbulence generated in the liquid was more intense within the vessel agitated by the forward-reverse rotating impeller. In the forward-reverse agitation mode, the agitation function of the impeller demonstrably enhanced the liquid-phase mixing, which shows a pattern with a higher level of mixedness. (c) 2007 Curtin University of Technology and John Wiley & Sons, Ltd.