Experimental and numerical investigations of motion and mass transfer of single bubbles in a turbulent flow chamber

Abstract

Background Gas-liquid mass transfer is a common transport phenomenon in the chemical industry. It is important to relate the mass transfer of single bubbles to the flow of the surrounding liquids. Many research on single bubbles mass transfer is on the experiment where the bubble is free rising in stagnant liquids, resulting a relative low liquid Reynolds number and short residence time. Therefore, the chamber flow is utilized to create a controllable flow field which can keep single bubbles in the chamber for a long period, which enables the accurate determination of the mass transfer coefficient.Methods First, the accuracy of three turbulence models describing the liquid flow in industrial stirred tanks were evaluated, by validating the liquid velocity and turbulent kinetic energy distribution in the chamber with experiments. Then, by coupling the turbulence model, volume of fluid method and several mass transfer models, the bubble motion and mass transfer were simulated. In this coupling approach, five classic models were respectively used to evaluate kL in the turbulent chamber flow.Significant findings This paper provides a reference for the selection of mass transfer model in the liquid flow chamber. The large eddy simulation is typically suitable for calculating turbulent liquid flow in the chamber. By coupling large eddy simulation and volume of fluid method, the mass transfer process of single bubbles in this cavity flow can be predicted. Considering the present partially contaminated and reactive system, Brauer mass transfer model can predict the mass transfer coefficient more accurately than other models.