Hydrodynamic characteristics of the industrial stirred tank bioreactor

 

J. Raffo-DurĂ¡n, A. Figueredo-Cardero and J.C. Dustet-Mendoza

 

 

This paper proposes the use of Computational Fluid Dynamics (CFD) to gain insight into the on flow patterns and other variables related to them in the industrial bioreactor for animal cell culture, and experimentation and to obtain information on the hydrodynamics by handling of the air flow and agitation operating parameters. We propose a mathematical model using the CFD tool, with which velocity fields comparable to those reported in the literature for a bioreactor with the same geometry as the one studied were obtained. By experimentation the time of mixing and the residence time distribution (RTD) were determined in the operating condition of the bioreactor (without aeration), and a flow pattern of perfect mix for the liquid phase was obtained. Also the mixing time was determined by CFD reaching a good approximation to that obtained experimentally. The operation of the bioreactor with air was characterized using a factorial experimental design 32 and the results obtained showed that the coefficient of volumetric oxygen transfer (kLa) depends on the variables stirring speed (N) and air flow rate (Qa).Using published correlations in the literature it was concluded that the phenomenon of flooding of the impeller occurs in the operating condition.