Collection Efficiency of Various Filter Media in Diesel Exhaust

Compliance of modern diesel engines with future European legislation for particulate emissions is possible only with the implementation of particulate traps known as Diesel Particulate Filters (DPF) in the exhaust of diesel engines. The types of filter media that can be used for that purpose vary according to material and geometric configuration. In this paper a number of ceramic extruded filters (SiC and Cordierite) as well as cylindrical cartridges embedded with fibrous structures were tested in terms of their collection efficiency for diesel soot particulates by using a newly developed optical nano-particle sensor with an adjustable optical path and an electric mobility based instrument.