Influence of fluid rheology on circulation, mixing and blending

Abstract

Abstract The measurements of the integral physical quantities such as circulation, mixing and blending times for helical screw impellers with the draught tube are presented in this paper. The influence of shear‐thinning and elastic properties of the liquids on these quantities are analysed both experimentally and theoretically. The overall circulation was found to be independent of the shear‐thinning character of the liquid. The influence of elasticity is considered in the light of the existing knowledge on sonic simple flow situations. A relation which incorporates the geometry of the mixer and the rheological properties of the liquid is proposed. The mixing and blending time results are analysed and related to the hydrodynamics using the laminar mixing approach of Mohr and his co‐workers. Although the analysis is approximate, it provides a useful tool in explaining the effects of rheology. It also suggests a way to estimate the blending times.