Separation of Saccharomyces cerevisiae from alcoholic fermentation broth by two commercial hydrocyclones

Two different commercial hydrocyclones, Doxie® type-A and AKW® type RWK 21, were employed to separate yeast from alcoholic fermentation broth and their performances were compared. The independent variables selected for this study were the pressure at the inlet of both hydrocyclones, the pressure on the underflow of the Doxie hydrocyclone and the underflow diameter of the AKW hydrocyclone. It was found that the AKW hydrocyclone showed better separation performance than the Doxie hydrocyclone, providing a separation efficiency of up to 89.13% and a processing capacity of more than 239.25 kg/h. Mathematical models were generated to predict the performance of the hydrocyclones (mass flow inlet, separation efficiency, flow ratio and reduced separation efficiency) under different experimental conditions. To evaluate the flow field of the hydrocyclones, a three-dimensional simulation was performed using the Large Eddy Simulation (LES) approach, providing detailed information about the flow and turbulence inside these devices, which was essential to understand the separation performance exhibited by them.