Studying the separation of particles in a turbulent vortex flow

摘要

This work deals with modeling the aerodynamics of a two-phase vortex turbulent flow in the separation chamber of a pneumatic centrifugal classifier. The velocity field of a gas-phase vortex turbulent flow is determined based on Reynolds equations closed with the Wilcox two-parametric turbulence model. The motion of a finely dispersed solid phase is modeled by calculating the trajectories of individual particles in the Lagrangian coordinate system with allowance for inertial, centrifugal, gravitational, and aerodynamic forces. The effect of the turbulent diffusion of particles due to the pulsating motion of a gas phase is predicted based on a semi-empirical probabilistic model. As shown by numerical calculations, the allowance for this phenomenon has a considerable effect on the separation of particles. The reliability of obtained results is confirmed by test studies and the comparison of numerical calculations with known experimental data. The effect of regime parameters on the aerodynamics and separation of finely dispersed particles in a pneumatic centrifugal classifier is also analyzed.