dieselpartikelfilters

Dieselpartikelfilter, often abbreviated as DPF, is a device in diesel exhaust systems designed to reduce particulate matter emissions. In German usage, the term Dieselpartikelfilter is widely used as part of the aftertreatment system. A DPF uses a porous substrate, typically cordierite or silicon carbide ceramic, or, in some cases, a metallic monolith, arranged as a wall-flow filter. The exhaust gas flows through the filter channels in such a way that soot particles are deposited on the channel walls, while the clean gas exits.

Over time soot builds up and must be removed through a regeneration process that oxidizes the stored carbon. Regeneration can be passive, occurring when exhaust temperatures are high enough during normal driving, or active, requiring additional energy input such as controlled fuel injection to raise the exhaust temperature. Some systems use a catalyst, often in combination with a diesel oxidation catalyst (DOC), to lower the temperature at which soot oxidation occurs.

DPFs are designed to capture a large fraction of soot, reducing particulate emissions to levels required by emission standards. They may be combined with other aftertreatment devices, such as selective catalytic reduction for nitrogen oxides. However, DPFs can be affected by sulfur poisoning or oil-related ash deposition, which can reduce performance and cause clogging if regeneration does not occur properly. Regular maintenance includes monitoring for warning indicators and periodic forced regenerations or ash/removal services.

In practice, DPFs have become standard in modern diesel vehicles to meet increasingly stringent regulations, with installation in passenger cars, light trucks, and heavy-duty applications.