Hydrodynamics of Two-Phase Upflow in a Pneumatic Classifier with the Variable Cross-Section

Abstract

This paper is aimed at the investigation of the two-phase upflow hydrodynamics in prismatic-shape apparatuses with the variable cross-section. To reach this aim, the mathematical model of the gas flow was developed based on the averaged in time and space velocities of the turbulent flow. This model is supplemented by the research of the solid particle movement in this flow. The research novelty of the proposed research is in the obtained dependencies for determining the velocity field of solid particles in a pneumatic classifier, as well as for estimating the friction coefficient. Additionally, equations for determining the velocity field of a gas phase were developed by velocity components of the two-dimensional gas flow. As a result, related graphical characteristics of the gas flow in the pneumatic classifier were built, and trajectories of solid particles were defined with respect to the apparatus width and height. The approach for evaluating empirical parameters was proposed based on the quasi-linear regression analysis. Moreover, the conducted regression analysis allows identifying the parameters of the mathematical model by the results of numerical simulations. The proposed approach will allow optimizing the technological and operating parameters of the pneumatic classification process and design of the related separation equipment.