CFD Simulations of High Efficiency Gas Cyclones: An Influence of Dustbin Geometry

Abstract

The unsteady state simulation of gas-solid cyclone separator was carried out to investigate the performances of 0.29 m diameter (DB) cyclones with five different dustbin geometries, including dustbin without dipleg (cylindrical bin) and dustbins with 0.5DB, 1.0DB, 1.5DB, and 2.0DB (divergent conical bin) height divergent conical diplegs. The diameter and total height of five dustbins were 1DB and 2DB, respectively. The gas flow and turbulence fields inside the cyclones with the Reynolds number of 280,000 were simulated by Reynolds averaged Navier-Stokes equations (RANS) with Reynolds stress model (RSM). The collection efficiencies were investigated by using discrete phase model (DPM). For model validation, the simulated velocity profiles of the cyclone with cylindrical dustbin have been compared to the previous experimental data available in literature and were in good agreement with the previous results. Further, the simulated results revealed that the Stairmand cyclone with divergent conical and simple cylindrical dustbins respectively represented the highest and lowest collection efficiencies indicated by 50% cut-off diameter, which corresponded to the diameters of 1.692 and 1.744 microns, respectively.