Pressure Drop and Flow Characteristics for a Heavy-Duty Air Filter During Dust Loading 872220

In order to examine the possible application of computational fluid dynamics to the prediction of the dust-loading characteristics of heavy-duty air filters, experimental studies have been made to obtain dust-loading data for a complete heavy-duty filter, for a complete filter with various sections of the outer cartridge surface blocked and for a panel of the cartridge. Tests on the complete and sectionalized filters were made on a facility corresponding to SAE Test Code J726. Tests on the panel were made on a separate apparatus.

Normalized plots of the dirty-to-clean stagnation drops versus the dust mass collected per unit face area showed that the data for the complete filter formed a single curve which was largely independent of air volume flow rate. This curve, when combined with clean stagnation pressure drop data, can be used to predict the variation of capacity with flow rate.

A series of tests were made with the complete and sectionalized filters in which the dust-loading test was interrupted periodically in order to inspect the dust-collection patterns on the pleats. Four dust collection patterns were observed. These patterns are the “uniformly” dusted pleat, a “separated” pattern in which dust collects on one-side of the pleat tip, a “two-sided” pattern in which dust collects on both sides of the tip, and a “bridged” pattern in which the pleat opening is completely closed.

THE POSSIBLE USE OF COMPUTATIONAL FLUID DYNAMICS to reduce the costs of development of new heavy-duty air filters has been discussed in Reference (1)*. The research program to investigate this possibility is concerned with the predictive accuracy which can be achieved and the manpower and computational costs which are involved. Specifically, full-scale model design, fabrication and testing would be replaced completely by numerical design until a satisfactory design had been achieved. If such a complete substitution was not possible, then some combination of numerical analysis and low-cost experiments might still provide significant cost savings. Reference (1) summarizes the status of the present effort relative to prediction of the clean pressure drop of heavy-duty air filters. This paper is concerned with studies of the dust-loading characteristics of these filters.