Study on the characteristics of flow field in disc partition in disc centrifuge

Abstract

In this paper, the characteristics of flow field in the disc partition divided by ribs and its influence on the separation efficiency of disc centrifuge were investigated by numerical simulation and experiment. The simulated results show good agreement with the experimented data. The shape and intensity of the vortex in the thin‐layer flow in the disc gap were significantly affected by the disc partition, as well as the solid–liquid two‐phase interface and particle concentration. The analysis of Q criterion indicated that vortexes with different scales and strengths in the disc gap were produced by the disc partition with higher intensity near the neutral hole and lower intensity away from the neutral hole. In addition, the increase of disc partition led to the decrease of the scales of vortex. Especially, the motion of solid particles in the disc gap was affected by the scales and intensity of vortex. There was a critical value of separation efficiency along with the disc partition (n = 6), that is, higher or less than this value leads to the decrease of separation efficiency. And the maximal separation efficiency is 14%, 3%, and 7% higher than the disc partition of 2, 4, and 8, respectively. This research revealed that the flow field in the disc gap could be controlled by the disc partition, as well as the intensity and distribution range of vortex, by which the separation efficiency of disc centrifuge could be improved. The results presented here may provide a workable reference for the design, optimization, and application of disc centrifuge.