CFD Modelling of the Fluid Flow Characteristics in an External-Loop Air-Lift Reactor

Knowledge about hydrodynamics in the external-loop air-lift reactors is the key in equipment design and process optimization. The aim of the study presented in this paper was numerical analysis of the sparger construction influence on the fluid flow characteristics in an external-loop air-lift column. Unsteady simulations of air - water dispersion flow in the reactor were performed using two fluid Euler-Euler numerical approach. Computational grids were created in commercial package ANSYS Workbench 2. ANSYS CFX 13 solver was used for numerical simulations. The Shear Stress Transport model was used for calculation of the turbulent momentum transport in the liquid phase. Results of the numerical simulation have been worked out in the form of the axial and radial distributions and contours of the gas hold-up, fluid velocity fields, kinetic energy of turbulence and its dissipation rate in the air-lift reactor.