The Effect of Classifier Chamber Configuration on Flow Field and Performance in Vertical Three-Cage Classifiers

To address the issues of insufficient pre-dispersion in the classification zone and inadequate powder-processing capacity in traditional turbine-type air classifiers, this paper proposes a bottom-fed vertical triple-cage classifier. Numerical simulations were performed using the finite element analysis software ANSYS FLUENT to compare and analyze the influence of the classifier chamber structure on flow patterns and classification performance. The results reveal that when the top diameter of the classification chamber is relatively large, with a top-diameter-to-rotor-diameter ratio of 1.45–1.50, the energy consumption of the rotating cage increases, and the scale of vortices within the classification zone increases significantly. Conversely, when this ratio falls within the range 1.30–1.35, wear on the chamber walls becomes markedly more severe. Among the tested configurations, the T-C-type chamber, which features a ratio of 1.40, proved to be the optimal structure, delivering a separation sharpness of 0.71 and a cut size (Dc) of 22.4 µm. This study provides a theoretical basis for the structural optimization design of such classifiers.