Modeling instantaneous pressure drop of pleated thin filter media during dust loading

In this paper, we present a modeling methodology for studying the effects of dust loading on the pressure drop across pleated filters. Our simulations demonstrate that there exists an optimum pleat count for clean filters at which pressure drop reaches a minimum regardless of the in-plane or through-plane orientation of the fibers. With the particle deposition included in the analysis, our results indicated that the rate of increase in pressure drop decreases with increase in the pleat count. We demonstrated that a higher pleat count results in a higher flow velocity inside the pleat channels causing more non-uniformity in the dust deposition across the pleat. Especially when particles are sufficiently large, the dust cake tends to form deeper inside the pleated channel when the pleat count is high. This effect is observed to be less pronounced when the pleats have a triangular shape. We also showed that if the dust cake permeability is higher than that of the filters fibrous media, the rate of increase in pressure drop does not always decrease with increase in the pleat count. Finally, by comparing filters having 15 pleats per inch, we observed that rectangular pleats are preferred over the triangular pleats when the particles are highly inertial, i.e., filtering high-speed large particles. When particle's inertia is small, our results indicate that triangular pleats cause less pressure drop, and so are recommended.

A new simulation method is presented to predict the rate of increase in pressure drop in pleated filters loaded with dust particles of different diameters. It is shown that the rate of increase in pressure drop decreases with increase in the pleat count. Filters having triangular pleats are shown to produce more uniform dust distribution and often perform better than their counterparts having rectangular pleats.Figure optionsDownload high-quality image (126 K)Download as PowerPoint slideHighlights
► A new methodology is developed to simulate dust loading in pleated filters.
► The rate of pressure drop increase due to dust deposition is simulated.
► The influence of pleat geometry on pressure drop is studied.
► Effects of air velocity and particle size on pressure drop are simulated.
► Reasonable agreement with published materials is observed.