Macromixing study for various designs of impellers in a stirred vessel

Abstract

The effect of the impeller designs and impeller clearance level (C/T) on power consumption, mixing time and air entrainment point in a single liquid phase under turbulent conditions (Re>10 4) were investigated. Different impeller designs including conventional and new designs, were used to consider both axial and radial flow impellers. The electric conductivity method, suspended motor system and observation method were employed to determine the mixing time, the power consumption and the air entrainment point, respectively. The reduction in the impeller clearance level form T/3 to T/6 resulted in a decrease in power number values for up-flow pumping impellers while it was increased for down-flow pumping. The same trend was observed for the mixing time results. Moreover, axial flow impellers and specially HE3 are preferable for higher agitation speeds due to the less air entrainment. The results verified that the axial flow impellers and specifically down-flow impellers are more efficient than the radial flow impellers. ANFIS-Fuzzy C-means (ANFIS-FcM) and nonlinear regression were used to develop models to predict the mixing time based on the energy dissipation rate and clearance. The results verified that the model predictions successfully fit the experimental mixing time data.

Computational prediction of blend time in a large‐scale viral inactivation process for monoclonal antibodies biomanufacturing

“…Because no actual experimental data were available for our system, we used the literature data to validate the computational prediction for Po, namely the results of (Afshar Ghotli et al, 2019; Afshar Ghotli et al, 2020) that these investigators obtained in a vessel of 0.3 m diameter ( T ) and height ( H ), equipped with four equally spaced wall‐mounted baffles with width, W B , of T /10 and agitated by a 0.1 m HE‐3 impeller with a clearance C equal to the impeller diameter. The vessel in that case had a flat bottom (as opposed to a torispherical bottom as in our system).…”

A qualitative study of mixing a fluid inside a mechanical mixer with the effect of thermal buoyancy

“…In addition to this, there are also some recently published papers [17][18][19][20][21][22][23][24][25], which on aggregate are hydrodynamic studies of the mixing process. The ultimate purpose of all these works is to reach a more efficient impeller that allows for speeding up the mixing process while reducing the consumption of mechanical energy.…”