A
Diesel Particulate Filter, shortly
termed as DPF, removes Diesel Particulate Matter from the exhaust
gas of a diesel engine. DPF cleans exhaust gas by forcing the gas
to flow through the wall of the filter. DPFs are made up of number
of materials; the most frequent is cordierite a ceramic material that
is also used as
catalytic converter supports and
silicon carbide. The device looks like catalytic converter nucleus
that have had alternate channels plugged - the plugs force the exhaust
gas to flow through the wall and the particulate collects on the inlet
face.
The DPF has numerous channels in analogous with
the ends plugged, in a checkerboard pattern. A DPF is regularly
followed by a lean NOx catalyst in a proprietary catalytic converter
for diesel engines. By entrapping the particulate matter, soot,
the DPF permits the lean NOx catalyst to work with no clog by the
soot. Hence the efficacy of the lean NOx catalyst
is not reduced by soot casing the active sites of the catalytic
converter.
These particle filters are a new technology: high
cost catalytic pollution control module added to diesel engined
cars to eradicate the attribute black smoke trail. It was first
presented as standard by the French manufacturers Peugeot
and Citroën in early 2005. Slow adoption by the German
car industry sparked local disapproval in March 2005. Despite costs,
the device will be mandatory for all newly built vehicles in the
EU starting in 2007.
