Powertrain Engines
Diesel Particulate Filter System
•
The DPF is a honeycomb structure with many channels closed off at alternate ends. The
soot particulates contained in the exhaust gas accumulate at the porous dividing walls,
while gaseous components such as CO and HC pass through the filter with no problem.
•
To prevent the filter becoming blocked with soot particulates, it must be ‘regenerated’ at
certain intervals, i.e. the collected soot particulates are burnt off. In order to facilitate the
regeneration process, the channels of the DPF feature a catalytic coating that lowers the
temperature required to burn off the soot particulates.
L1001.4_01147
1 Soot
2 Catalytic
coating
•
Pressure and temperature sensors in the DPF detect when the soot accumulation
capacity of the filter is reached. Then the engine control system increases the exhaust
gas temperature by multiple fuel injections to burn off the particulates.
Curriculum Training
01-75