Using computational fluid dynamics to analyze the performance of the Maxblend impeller in solid-liquid mixing operations

Abstract

Solid- liquid mixing is prevalent in several industries due to its wide range of utilization in various unit operations. The goal of this work was to examine the performance of the Maxblend impeller for the particle suspension in a slurry tank employing the computational fluid dynamics (CFD) technique. The CFD model was created using the Eulerian and Eulerian (E-E) method, standard k-ε turbulence model, and sliding mesh (SM) technique for simulating the two-phase fluid flow, turbulence effects, and stirrer rotation, respectively. The CFD model was validated by comparing and analyzing the results obtained from the generated model to the experimental data in terms of stirrer torque, just suspension speed, and degree of homogeneity obtained from the tomography technique. The validated model was utilized to obtain the particle concentration profiles and to determine the local particle distributions attained by the Maxblend impeller. The data were utilized to analyze the impacts of various important parameters such as the agitation speed, particle concentration, particle diameter, specific gravity of the particle, and the use of baffles on the mixing efficiency of the Maxblend impeller in terms of the extent of homogeneity. A new mixing index was adopted to understand the effect of both axial and radial concentration gradients on the mixing performance of the Maxblend impeller. The particle distribution in the slurry reactor furnished with a Maxblend impeller was also assessed through clouding height approach in this study.