Investigations of particle penetration in fibrous filters Part II. Theoretical

This article is the second part of a two-part series. The first part, "Inve stigation of Particle Penetration in Fibrous Filters: Experimental," appear ed in the January/February, 1999 issue of the Journal of the IEST. The performance of seven state-of-the-art air cleaning filter media having a wide range of filter efficiencies is described. The figure of merit value s have been obtained to compare the performance of different media. The exp erimentally obtained pressure drops and the theoretically calculated fiber drags are used in deriving an expression to calculate an equivalent fiber d iameter for different media. The theoretical values of fiber diameter compa re well with the experimental observations. Use of the equivalent fiber dia meter values in calculating the parameters of the dimensionless correlation model results in better agreement between the experiments and theory. The calculated equivalent fiber diameter is useful in predicting the mast penet rating particle size of different media.