Experimental study on fluid flow of red mud separation thickener feedwell

Based on the similarity principle, a red mud separation thickener water model was established with the geometry ratio at 1:20. Finite granules trace method and residence time distribution (RTD) were chosen as the trace method and evaluation criteria respectively. Experiments were carried out to investigate the flow patterns of the thickener feedwell as well as RTD under different operating conditions. Two different non-ideal flow models were adopted to describe flow mixing extent in the feedwell in conjunction with the moments and non-linear regression calculation techniques. The results show that the moving fluid in the feedwell can be depicted as Swirling flow. Furthermore, the stagnant areas and short circuiting are found in the feedwell. The volume fraction of the stagnant zone decreases by 7.7% as the inlet flow rate increases from 0.20 L/s to 0.30 L/s. When the feedwell aspect ratio decreases from 1.60 to 0.75, the volume fraction of the stagnant zone decreases by 15.9%. There exists relative large magnitude mixing movement in the feedwell, and the extent of the mixing behavior increases with the increase of inlet flow rate and the decrease of feedwell aspect ratio. ©, 2015, Central South University of Technology. All right reserved.