CFD Analysis Of Particle Laden Flow In A Cyclone Separator Using Rans And Les Methodologies

Abstract

This study is concerned with the most common reverse flow type of cyclones where the flow enters to the cyclone through a tangential inlet and leaves via an axial outlet pipe at the top of the cyclone. In the present work numerical simulation of three-dimensional particle-gas turbulent flows in the Stairmand High Efficiency cyclone separator is carried out using ANSYS FLUENT . In the present work, all simulations are carried out using ANSYS FLUENT having the same inlet Reynolds number, R e = 91327 and the same solid-air loading ratio (ṁs/ṁa) of 0.06. Euler-Lagrange approach is used to simulate solid-gas flow inside cyclone where fluid is simulated in eulerian framework and solid particles are simulated in Lagrangian framework. The nature of the gas-solid flow inside cyclone is highly swirling and anisotropic turbulent. Therefore, advanced turbulence models like Reynolds Stress Model (RSM) and Large Eddy Simulation (LES) is applied for fluid flow simulation hence solid particles are simulated using Discrete Phase Model (DPM). The objective of this study is to optimize the cyclone performance by optimizing the geometrical parameters. First, to determine the significant parameters affecting the cyclone performance which is based on the previous studies i.e. vortex finder diameter, cone length, barrel height, vortex finder length and con-tip diameter. Second, to study each single parameter separately having different ranges for each parameter to obtain more details about its effect on the flow field pattern and the performance. For this, initially sixteen simulations are carried out using steady state Reynolds stress model (RSM). Finally, to obtain the most efficient cyclone designs i.e. design for minimum pressure drop, design for maximum collection efficiency and the final optimum design (having optimum pressure drop and optimum collection efficiency), simulations are done using transient Large Eddy Simulation (LES). These optimum configurations are identified based on five significant parameters performance curves of sixteen steady state simulation using RSM. Key Words: Cyclone separator, Reynolds stress model (RSM), Large Eddy Simulation (LES), Discrete phase modeling (DPM), Vortex finder diameter, Cone length, Barrel height, Vortex finder length and Cone-tip diameter.