An engineering study of solid-liquid suspension in shaken and stirred bioreactors

• Main Author: Esbati, E.
• Published: University College London (University of London) 2013
• Subjects: 660.6
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.626238

Using shaken microwell and stirred miniature bioreactors in early stage bioprocess development requires understanding such devices from an engineering perspective. One particular area which has not to this date been fully explored is the suspension of solid particles in multi-phase operations in such devices. In order to broaden our understanding of this phenomena, a novel correlation is described for predicting the minimum shaking frequency required to suspend at least 90% of solid particles (0.81 gml−1 < ρp < 1.33 gml−1) present in a bioprocess involving shaken microwell operations. It was found that predictions made by this correlation are in good general agreement with empirical data with an uncertainty figure of just ±17%. Suitability of Zwietering’s correlation for predicting the minimum stirring frequency required to suspend solid particles in a miniature and a laboratory scale stirred tank was examined by comparing its predictions to empirical data. It was found that the correlation overestimates the required agitation rate, sometimes by as much as ≈ 70%, for the miniature bioreator. Flow inside the two stirred tank bioreactors were also numerically simulated and the results found to be in general agreement with the empirical data.