Study of the short-circuit flow and circulation flow's impact on separation performance of cyclone separator with volute-helical inlet

Short-circuit flow and circulation flow are important secondary flows in a cyclone, which have a negative impact on separation performance. This work proposed new cyclones (VH cyclone), incorporating volute-helical inlets with five tilt angles based on the characteristics of short-circuit flow and circulation flow, in order to enhance separation efficiency without a significant pressure drop compared to a Lapple-type cyclone with a tangential inlet (TI cyclone). The separation performance and Euler number of six cyclones are obtained by experiments and analytical models. The simulation is utilized to explore characteristics of short-circuit flow and circulation flow, with a focus on the impact of these flow patterns on particle motion. The result shows that proportion of short-circuit flow increases initially and then decreases with the increase of the tilt angle, while circulation flow is continually weakened. The cutoff diameter increases first and then decreases while the trend of Euler number is opposite for new cyclones. By considering both separation performance and Euler number, VH4 cyclone (Tilt angle of volute-helical inlet is 6.5°) exhibits optimal performance, with a cutoff diameter 20.41% lower than that of TI cyclone, while their Euler numbers are similar.