The aim of this study is to determine optimum operating conditions for a self-aspirating disk impeller on the basis of mass transfer coefficient per unit of mixing power, kL/PG.
Gas bubble sizes and interfacial area of the system were calculated using a photographic method and the impeller operation efficiency was presented on the basis of measurements of the volumetric mass transfer coefficient. For the tested impeller, the values of mass transfer coefficient are settled starting from Fr'≈0.4.
In the case of electrolyte solution (NaCl), the mass transfer efficiency is slightly lower than in the case of liquids being non-electrolytes, e.g. water and rokrysol solution
A method to determine mixing power of screw impellers in evaporating crystallizers is proposed. Relevant calculations were made on the basis of two numerical coefficients whose values are determined experimentally.