Optimization of spiral guide vane for tangential inlet cyclone separator based on CFD and response surface methodology

The inlet geometry influences the development of short-circuit flow and the performance of the tangential inlet cyclone. The spiral guide vane (a special inlet geometry) within annular space of the cyclone is proposed to guide initial flows, decrease short-circuit flow rate and enhance performance. This study is to investigate the effects of spiral guide vanes on the flow field and performance of the cyclone, and then determine an optimal spiral guide vane geometry by computational fluid dynamics (CFD) and response surface methodology. The influence of spiral guide vane dimensions (length, width, and helix angle) is investigated at first, and two key factors (width and helix angle) are identified. Then the width, helix angle, and inlet velocity are selected to calculate sample points, and predicted models of separation efficiency and pressure drop are developed. Finally, Pareto solutions are gained to determine the best-performing spiral guide vane design for the cyclone. When the spiral guide vane helix angle is 2.84°, the spiral guide vane width is 0.013 m, and the inlet velocity is 12.32 m/s, the studied tangential inlet cyclone has the best performance. Compared with original design without spiral guide vane, the collection efficiency of fine particles (1 μm) for the optimized cyclone increases by almost 13%, the separation efficiency increases by 2.30%, and the pressure drop decreases by 8.41%.