Intensification of suspension of solid particles in non-Newtonian fluids with coaxial mixers

Abstract

The coaxial mixers intensify the suspension of solids in complex fluids, which is highly desirable for process intensifications in food processing, pharmaceuticals production, and cosmetics manufacturing. The prime aim of this research work was to examine the mixing efficacy of a coaxial mixing system, comprising of a close clearance outer anchor and an inner axial impeller, in intensifying the suspension and dissemination of solid particles in carboxymethyl cellulose (CMC) solutions employing response surface methodology (RSM) and electrical resistance tomography (ERT). RSM was utilized in this research study to examine the impacts of three different numeric factors and one categoric factor on two response variables. The ERT conductivity data were utilized to generate axial as well as radial concentration profiles. The solids distribution quality in CMC solutions was assessed employing three different mixing indexes. The fluid flow patterns generated by the coaxial mixers in suspending and dispersing the solids in CMC solutions was obtained utilizing computational fluid dynamics (CFD) turbulent modeling approach. The influences of various important factors namely outer anchor speed, speed ratio, solids content, CMC concentration, average particle size, inner impeller types, and rotating mode on the slurry suspension and dispersion behaviour were comprehensively analyzed in this study.