Mechanisms Influencing Crystal Breakage Experiments in Stirred Vessels

Abstract

Crystal breakage experiments in saturated solutions and nonsolvents often fail to accurately represent breakage in a suspension crystallizer because the saturated solution experiments have other mechanisms occurring, and the nonsolvent experiments have different particle dynamics and hydrodynamics. This research investigates NaCl crystal breakage in an aqueous saturated solution and in the nonsolvent acetonitrile at different magma densities and agitation rates to determine the significance of these effects. It is concluded that due to significant agglomeration in a saturated solution a nonsolvent should be used. The approach of performing experiments with both suspension fluids at the same magma density, and using the Zwietering correlation to adjust the agitation rate of the nonsolvent experiment for comparison with the saturated solution is shown to decrease the differences between the resulting crystal size distributions compared to operating both systems at the same agitation rate.