Numerical study of gas-solid flow in a square cyclone separator with different vortex finders

Abstract

In this study, the influence of a vortex finder shape with different hydraulic diameters on the pressure drop, flow pattern, and separation efficiency of a square cyclone separator was analyzed using Computational Fluid Dynamics (CFD). The considered vortex finders included square and cylindrical shapes with hydraulic diameters of 0.25, 0.5, and 0.75 times the square part hydraulic diameter of the cyclone separator. In this study, the Euler–Lagrange approach was applied to model two-phase flow inside square cyclone separators. The results demonstrated that the use of a cylindrical vortex finder increased the pressure drop and separation efficiency. Moreover, as the relative hydraulic diameter changed from 0.5 to 0.25, the pressure drop increased ten-fold, and the separation efficiency increased from 34.2 % to 83.1 % at an inlet velocity of 20 m/s and a particle diameter of 8 µm. In the cyclone separator with De/D= 0.75, employing the square vortex finder led to a decrease in the separation efficiency and an increase in the pressure drop compared to the cylindrical vortex finder because of dividing the inlet flow into two branches.