EVALUATION OF PERFORMANCE OF MIXING APPARATUS FOR HIGH VISCOSITY FLUIDS

Abstract
There exists no universally accepted technique for evaluating the functional status of equipment for high-viscosity mixing based upon generalized basic information such as flow patterns and shearing deformation characteristics. This paper deals with the measurement of flow patterns. After obtaining the overall flow patterns in a mixing vessel, circulation capacity and fluid deformations which cover information about energy dissipation were correlated with the homogenizing time. The physical meanings of C1=nTM and C2=TM √Pυgc/μ are interpreted by using a concept of striation thickness. A measure of an averaged dimensionless shear rate number √Pυgc/μ/n is plotted against the dimensionless nearest distance between moving part and fixed wall in the mixing vessel. This diagram could give an useful comparison as to averaged shear rate characteristics for any device for high-viscosity mixing regardless of geometrical configuration. A novel technique is also proposed for quick evaluation of the shear distribution in a given apparatus.