Fine particle sorting and classification in the cyclonic centrifugal field

Fine particle sorting and classification are not only important processes during the powder preparation, but also vital to the sequential separation of discrete fine particles with different sizes. The moving fine particles with different sizes have different trajectories in the cyclonic centrifugal field under the actions of radial and axial forces, which inspire us to develop a novel cyclonic multi-product sorting classifier. Both particle size and mass distribution gradually increase axially from the inlet side to the outlet side and radially from the inside to the outside at the rectangular outlet of the sorting classifier. When the mean particle size of the inlet is 15.7 mu m and the coefficient of variance is 90.1%, 12 different particle sizes (the minimum and maximum particle sizes are 8.41 and 26.16 mu m, respectively) with better monodispersion are obtained, all products achieve a particle coefficient of variance below 40%. An effective calculation method was used to represent the overall sorting and classification performance of sorting classifiers with different height. The results show that the best height is 5 times as high as the rectangular inlet, and the optimum gas flow is 30-60 m(3)/h with the pressure drop not exceed of 80 Pa. The present study could also serve as a useful guide in the industrial sequential separation and capture of fine particles of different sizes. Notably, it may exhibit a high potential for the control of PM2.5 throughout studies in future. (C) 2015 Elsevier B.V. All rights reserved.