Numerical Investigation on the Effects of Pipe Rotation on a Dynamic Hydrocyclone

Abstract

Dynamic hydrocyclone and compound hydrocyclone are both new high efficiency separators whose difference is whether the pipe wall (wall of separation chamber) is rotating when working, but the influences of rotating pipe on hydrodynamics and performance of dynamic hydrocyclone has not been well studied. In this paper, a three dimensional numerical simulation applying Reynolds Stress Model (RSM) coupled with Multiple Reference Frame (MRF) model and algebraic slip mixture model was conducted to analyze flow field of dynamic hydrocyclone with and without pipe rotation. The results show that, pipe rotation can accelerate the flow around the wall leading to an increase of tangential velocity as well as avoidance of large velocity gradient around the wall. On the other hand, pipe rotation has little impact on axial velocity. And investigation on the turbulence shows that pipe rotation may effectively attenuate turbulent transport. What’s more, pipe rotation significantly improves aggregation effect of oil droplet, which leads to an increase of separation performance.