RAM 3500 Chassis Cab Truck 2WD L6-6.7L DSL Turbo (2010)
Diesel Particle Filter (DPF): Description and Operation
DESCRIPTION
1.
The After treatment System consists of three catalyst elements, all working together to drastically reduce tailpipe emissions:
DIESEL OXIDATION CATALYST (DOC)
The Diesel Oxidation Catalyst (DOC) is a ceramic flow through substrate coated with a catalyst waistcoat that is integral to the DOC assembly. The close
coupled DOC treats engine exhaust gases by converting harmful carbon monoxide, unburned hydrocarbons and other compounds into water, carbon
dioxide and heat.
Pick-up vehicles use a separate DOC assembly.
Cab-Chassis vehicles use a combination Diesel Oxidation Catalyst/Diesel Particulate Filter (DOC/DPF)
CLOSE COUPLED CATALYST (CCC)
The CCC is basically a diesel oxidation catalyst (DOC) that is mounted very close to the turbocharger exhaust outlet. It is a metallic flow through
substrate coated with a catalyst waistcoat that is essential to the integrated operation of the after treatment assembly. The close coupled DOC treats
engine exhaust gases by converting harmful carbon monoxide, unburned hydrocarbons and other compounds into water, carbon dioxide and heat. The
ability to create heat is an important part of the system regeneration process.
NOx ADSORBER CATALYST (NAC)
The NAC is located downstream of the CCC. Using the heat and exhaust constituents coming from the CCC, the NAC traps various oxides of nitrogen,
and then converts those into Carbon Dioxide, Nitrogen (N2) and water via a regeneration process controlled by the engine's electronic control module
(ECM). The NAC also plays a role in reducing non-methane hydrocarbons (NMHC) from the exhaust gas.
DIESEL PARTICULATE FILTER
The NAC is located downstream of the CCC. Using the heat and exhaust constituents coming from the CCC, the NAC traps various oxides of nitrogen,
and then converts those into Carbon Dioxide, Nitrogen (N2) and water via a regeneration process controlled by the engine's electronic control module
(ECM). The NAC also plays a role in reducing non-methane hydrocarbons (NMHC) from the exhaust gas. DIESEL PARTICULATE FILTER (DPF):
The diesel particulate filter (DPF) is a wall-pass ceramic filter substrate coated with a catalyst waistcoat. It is located just downstream of the NAC.
Exhaust gases flow from the NAC into the catalyzed diesel particulate filter (DPF) which traps and accumulates particulate matter, and further treats the
exhaust gases to reduce any remaining unburned hydrocarbons and other harmful compounds. The trapped particulate matter will be periodically
removed from the DPF via a regeneration process controlled by the engine's electronic control module (ECM).
