Prediction of Power Consumption in a Mechanically Agitated Gassed Reactor in Viscous Batches

Volumetric mass transfer coefficient, power input, and gas holdup are key parameters in the design of mechanically agitated gas‐liquid contactors. Although the majority of industrial batches are of higher viscosity, reliable transport characteristics correlations for viscous batches are lacking in literature. These correlations are often based on the power input as the scale of energy dissipation. In order to develop reliable power input correlations, its measurements were carried out in a pilot‐plant vessel using multiple impellers of various types and diameters. Power input correlation shapes providing the best match with the comprehensive database are also expected to predict most precisely the impeller power in industrial‐scale vessels. Scalable correlations for power consumption in a viscous batch for various impellers with different impeller‐to‐vessel diameter ratios were developed. With the aim to determine one of the design parameters for industrial fermenters, power consumption in laboratory and pilot plant vessels was measured. Viscous batch behavior was found to be similar to that of a non‐coalescent batch.