The effects of inlet number and positions on the flow pattern and performance of a Stairmand cyclone

This study conducts numerical investigations to analyze the influence of inlet number and vertical positioning on flow patterns, collection efficiency, pressure drop, and efficiency of Stairmand cyclones. The maximum displacement of inlets is considered approximately equal to the cyclone diameter, and the inlets are arranged in a gradual manner. The Reynolds Stress Turbulence model (RSM) was employed to calculate flow properties in turbulent conditions. Out of the 44 cases examined, the four-inlet cyclone with L4 = 0.1 exhibited the smallest cut-size diameter, while the single-inlet cyclone with L1 = 0.9 displayed the lowest pressure drop. Notably, shifting one of the inlets of the two-inlet cyclone by 20% relative to the cyclone diameter resulted in higher pressure levels on the cyclone wall compared to other geometries explored in this study. Collection efficiency in cyclones is generally enhanced by an increase in tangential velocity, but it is also influenced by the position of the inlet(s).