Pressure Drop of Segmented Diesel Particulate Filters

Segmented, Silicon-Carbide Diesel Particulate Filters appear to be automotive industry's popular choice for reducing particulate emissions of Diesel Engines, particularly for light duty platforms. Since flow resistance represents an important performance feature of a filter, it is important that reasonable prediction tools for such filters are developed for use in their development, design, applications and regeneration control. A model for predicting pressure drop of segmented filters is presented here: an existing, well-accepted pressure drop model for monolithic (non-segmented) filters is customized to one for a segmented filter using a ‘weighted number of inlet channels’ based on equivalent filtration wall area of a monolithic filter. Flow resistance data collected experimentally on segmented filters are used to demonstrate the accuracy of the new model. It is exhibited that segmentation could increase a filter pressure drop by up to 30 - 35% depending on the particulate loading, thus necessitating choosing higher cell density segmented filters to diminish this effect. Relative significance of the four components of filter pressure drop is also discussed for both monolithic and segmented filter with or without particulate loading.