Trapping Performance of Fine Particles from a Diesel Engine by Various DPFs with Different Surface Structures

The regulation of particulate matter (PM) from diesel engines is coming to be very stringent at present. The usage of diesel particulate filter (DPF) is now under consideration in many heavy-duty diesel vehicle manufacturers to reduce PM emission from a diesel engine. The possibility that very fine particles may pass through DPF is suggested. The understanding of fine particles emission behaviors and the countermeasure of reducing particle emissions from DPF will come to be important in near future. The behavior of particle size distribution after DPF has not been studied enough yet.

In this study, fine particles generated by a diesel engine are introduced to honeycomb type and SiC (Silicon Carbite) fiber type DPFs and the collection performances of fine particles by various DPFs with different surface structures have been examined. Moreover, the simultaneous measurement of particle size distribution before and after various DPFs by two ELPIs (Electric Low Pressure Impactor) has been carried out and the relationship between the change of exhaust gas flow and the trapping of fine particles has been investigated under various transient driving conditions. As the result, it can be seen that while an increase in exhaust gas flow rate through the active regeneration type SiC fiber DPF has influence on a decline in trapping efficiency, a new alumina-coated active regeneration type DPF can be considered effective in trapping PM ultrafine particles.