Collection Efficiency of Rectangular Slit-Nozzle Inertial Impactors with Impaction Plates of Elliptical Concave Curvature
Abstract:In this study, the impaction plate with an elliptical concave groove was employed in an effort to enhance the collection efficiency of the slit-nozzle inertial impactor. The major axis length (A) and the minor axis length (B) of the elliptical concave curvature were varied. The effect of the ratio of A to B on the collection efficiency of slit-nozzle inertial impactors was investigated both numerically and experimentally. The numerical results were in good agreement with the experimental data for different values of A/B ratio. The elliptical concave impaction plates were useful in not only reducing the particle bounce but also lowering the cut-off size. The optimum range of the A/B ratio was found to exist for minimizing the cut-off size. When the elliptical concave impaction plates with the A/B ratio of 2 were used for the slit-nozzle inertial impactors, the square-root of the Stokes number was estimated to be lowered from 0.77 to approximately 0.6, resulting in the decrease of the cut-off size by 22% compared with the typical flat impaction plates.
Copyright 2013 American Association for Aerosol Research
Document Type: Research Article
Publication date: 2013-01-01