Effects of operational and geometrical parameters on velocity distribution and micron mineral powders classification in cyclone separators

The application of cyclone separators in the classification of micron powders can achieve satisfactory performance with low operation costs. The effects of operational and geometrical parameters including the inlet velocity, vortex finder length, and vortex finder diameter on the velocity distributions and classification performance of micron powders in cyclone separators were studied via CFD simulation and experiments. The results revealed that the inlet velocity and vortex finder diameter significantly affect velocity distribution and particles separation owing to changes in swirl intensity and axial backflow. The vortex finder length influences the positive effects of vortex finder, and a sufficient length should be chosen to weaken the disturbance of inlet airflow and enhance particles separation. The classification results of micron ground calcium carbonate powder indicated that these parameters all significantly affect the cut size and classification sharpness, and moderate values of these parameters should be selected to obtain a satisfactory classification performance. • Optimizing vortex finder enhances powder classification in cyclone separators. • Sufficient inlet velocity is essential for micron powder centrifugal separation. • Vortex finder length determines short-circuited flow and bypass particles. • Vortex finder diameter affects swirl intensity and axial backflow drastically.