Hydrodynamics and mass transfer in a bioreactor with gas-to-liquid supply from the vortex cavity

Abstract

The results of the study of hydrodynamic and mass transfer parameters of a stirred bioreactor during gas dispersion from the cavity of an open vortex to the area with reduced pressure in the liquid behind the impeller paddles are presented. New data were obtained on gas content, dispersed composition of gas bubbles, stirring power, and intensity of mass transfer in the air-water system, aqueous solutions of sucrose and glycerol of various concentrations and with different content of surfactants. The dependence of the stirring power on the gas content and Reynolds number, as well as the mass transfer coefficient on the boundary surface and energy dissipation, have been established. It is assumed that when calculating the dissipation of energy spent on developing a boundary surface, it is necessary to take into account the influence of viscous friction forces in the liquid. Dispersion of gas into liquid through an open vortex cavity in a stirred bioreactor allowed to increase the gas content, the boundary surface and to intensify mass transfer compared to conventional aeration systems.