A direct approach to the design of cyclones for aerosol-monitoring applications

During the past four decades, many investigators have attempted to discover models to describe the performance of cyclone aerosol selectors. These eff orts were in general not successful and resulted in "semi-empirical" relati onships of narrow application. The introduction of regulatory size-selectio n curves for air-monitoring applications means that it is no longer adequat e to predict only the median cut point (D-50) of a size selector. This furt her complicates the search for a useful cyclone model. Building on previous work, a completely empirical investigation was devised which has resulted in the development of the "Family" approach to cyclone design, and a method for predicting both the D-50 cut point and the shape (or slope) of the sel ection curve. Three cyclone families have been developed and tested, which cover the current range of requirements for size selective particulate samp ling. Although this empirical approach does not advance the physical unders tanding of cyclone separators, it does provide a practical means to design cyclones for specific applications. (C) 2000 Published by Elsevier Science Ltd.