Effects of the geometric configuration on cyclone performance

Abstract

A cyclone׳s performance can be optimized by changing its configuration, which is a very challenging task that depends on critical performance indicators. In this work, a comprehensive overview of the effects of a cyclone׳s longitudinal and radial dimensional ratios (including a/Dc, b/Dc, De/Dc, S/Dc, h/Dc, H/Dc, B/Dc) on its cutoff size, pressure drop, as well as the steepness of the sampling curve, was briefly reviewed. In addition, systematic experimental examinations were conducted to investigate different effects of geometric configurations on cyclone performance, and the optimal ranges for the geometric dimensional ratios were proposed. The results were analyzed according to four cyclone geometric components: the overall cyclone body, the cyclone contraction cone, the vortex finder (V.F.), and the inlet, and were compared to the observations reported in the literature. It was found that the effect of the overall cyclone body height (H) is closely related to the natural vortex length (Lv). The optimal H/Dc value based on the compromise between small dimensionless cutoff size (d50˜) and dimensionless pressure drop (ΔH) is around 5.5–7.0, which is slightly larger than the traditional Stairmand design. A cyclone with a short and wide cone would have a steeper cutoff curve and larger optimal H/Dc value than one with a long and sharp cone. Although a cyclone with cone results in higher collection efficiency, the slope of the efficiency curve is less steep than one without cone. On the other hand, both the collection efficiency and sharpness of the collection curve of a cyclone could be improved by reducing the outlet diameter and using an inlet with higher aspect ratio. The d50˜ can be double and ΔH can be reduce 70% by varying the De/Dc from 0.28 to 0.71, while the effect of the inlet aspect ratio (a/b) is relatively insignificant.