A NEW METHOD FOR THE DETERMINATION OF THE INTERCEPTION EQUIVALENT DIAMETER

Interception is one of the important particle deposition mechanisms. Nevertheless there is at present no practical and efficient method to characterise non-spherical particles with respect to interception and assign a unique equivalent diameter. A new method for the determination of the interception equivalent diameter dR is presented. The method is demonstrated on cluster-cluster grown carbon agglomerates, themselves representing an important group of non-spherical particles in industry, with diffusion equivalent diameters from 0.04 up to 0.9µm. dR was determined on the basis of penetration measurements through a model filter with the agglomerates and spherical wax particles in the diffusion-interception regime. The measurements show that dR was independent over a range of filter face velocities of 0.6, 1.7 and 4.8cms-1. This indicates that the equivalent diameter dR, determined according to the present method, represents a particle property, independent of the parameters of the measurement process.