A scale-up framework for aerated coaxial mixers with yield-pseudoplastic fluids

The volumetric mass transfer coefficient is crucial for evaluating two-phase mixing performance, and experimental data from large-scale systems are essential to bridge the gap between lab-scale studies and industrial applications. This study provides pilot-scale data for aerated PBT-anchor coaxial mixers with xanthan gum solutions and proposes a scale-up framework designed to maintain constant mass transfer performance based on findings from a 50-L setup. Experimental validation in a 170-L vessel was conducted, and further refinement strategies were employed, yielding a maximum error of 14.65 % for the volumetric mass transfer coefficient and a reduction in power consumption by up to 14.52 %. Computational fluid dynamics (CFD) simulations for a 785-L vessel demonstrated the framework’s scalability, provided that the flow regime does not transition to flooding. Overall, combining CFD simulations with the refined scale-up strategy ensures the framework's validity, leading to cost savings and offering a practical approach for efficient bioreactor scaling. • Proposed an efficient scale-up framework for aerated coaxial mixers. • Experiments validated scale-up for constant volumetric mass transfer coefficient. • CFD results confirmed scale-up predictions for larger vessel sizes. • Framework valid as long as flow regime avoids transition to flooding. • Combining simulations and experiments boosts efficiency and cost savings.