Impact of cone wall roughness on turbulence swirling flow in a cyclone separator

The influence of cyclone cone wall roughness on swirling flow characteristics is evaluated by considering different numbers of the inlet when the total flow rate is kept constant. Three-dimensional simulations are performed using the Eulerian–Lagrangian approach and RSM turbulence model. Effective parameters such as tangential and axial velocity distributions, turbulence intensity, pressure drop, particle collection efficiency, and erosion rate are investigated for the various number of inlets and different values of cone roughness. The results demonstrate that tangential and axial velocities are enhanced with the cone roughness. The pressure drop decreases with the cone roughness and increases with the inlet velocity. It is demonstrated that cutoff size diameter is affected by the number of inlets and cone wall roughness. For example, the three-inlet cyclone with a smooth-walled cone can collect 22.3-μm particles, while this cyclone collects 19.7-, 17.6-, 17-, 16.6-, and 16.2-μm particles when cone wall roughness is 0.2, 0.5, 1, 2, and 3 mm, respectively. Besides, it is observed that the collection efficiency is affected by the roughness slightly for the cone roughness ranging from 3 to 6 mm. The results demonstrate that the wall erosion rate is reduced with the cone wall roughness. It is maximum for the one-inlet cyclone and is minimum for a three-inlet one.