A single-phase turbulent flow numerical simulation of a cyclonic-static micro bubble flotation column

摘要

Improved fluid dynamics can enhance the separation efficiency of flotation methods. A Computational Fluid Dynamics simulation using FLUENT was performed to model the fluid environment of a cyclonic-static micro bubble flotation column. The simulation results visually show the interior flow and illustrate mixing of the different flows within the apparatus. An analysis of the distribution in velocity and vorticity was used to analyze the separation mechanism and the synergism of the component parts and to strengthen the design of each unit. The conclusions are that axial back mixing and vortexes still exist in the separation unit even in the presence of packing media. The inverted cone structure near the tangential inlet (cone 1) within the cyclonic unit is the main reason for this. The cone 1 structure enhances swirling and focuses energy within the inner area of the cone where there are abundant bubbles. As a result slowly floating minerals are forcibly recovered and tailings are effectively separated within this unit. However, cone 1 also reduces the vorticity downstream from it, which reduces the efficiency of tailings separation within this part. Therefore, the design of cone 1 should be based on the principles of lessening disturbances to the column unit while strengthening the separation effect of the cyclonic unit. Also, the axial distance between the paired cyclonic structures at the bottom of the column (cone 2) and cone 1 poses tough requirements because of an interaction between separation of the middlings and tailings.