Abstract
The particle diameter at 50% partial collection efficiency is usually used as critical cut size to evaluate a particle separator. However, such assumption is not adequate for exact estimation of the overall collection efficiency, because the latter depends on the inlet particle size distribution too.
The theoretical correlations between overall collection efficiency and equilibrium (real) cut size are herein derived, assuming the Rosin-Rammler or the logarithmic normal distribution for the inlet particle size. The ratio of the equilibrium and an arbitrary cut size is also calculated for any R-R distribution, assuming an equation of partial collection efficiency. As an example, this calculation method is applied to the measurement of size distribution of monodisperse aerosol by a two-stage cascade impacter.
