This article is the second part of a two-part series. The first part, "Investigation of Particle Penetration in Fibrous Filters: Experimental," appeared 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 values have been obtained to compare the performance of different media. The experimentally obtained pressure drops and the theoretically calculated fiber drags are used in deriving an expression to calculate an equivalent fiber diameter for different media. The theoretical values of fiber diameter compare well with the experimental observations. Use of the equivalent fiber diameter 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 most penetrating particle size of different media.