GROWTH-INDEPENDENT BREAKAGE FREQUENCY OF PROTEIN PRECIPITATES IN TURBULENTLY AGITATED BIOREACTORS

A model is provided to describe the influence of hydrodynamic conditio ns on the breakage of protein precipitates in turbulent suspension. To examine the applicability of the model, experiments are performed to measure the breakage of soya protein precipitates in a 0.29 m diameter vessel at impeller Reynolds numbers ranging from 3.6 x 10(4) to 5.6 x 10(5) and with initial protein concentrations of 0.35, 3.5 and 35 kg/ m3. An analysis of the experimental results based on the proposed mode l shows that the initial frequency of breakage of protein precipitates is a unique function of the energy dissipation rate in the vessel, en compassing both effects of impeller diameter and impeller speed. The m odel accurately describes the influence of both energy dissipation rat e and protein concentration on the initial breakage frequency of the a ggregates.