DCA300SSJU4F2 60 HZ GENERATOR• OPERATION MANUAL — REV. #0 (06/26/18) — PAGE 53
MAINTENANCE
EMISSION CONTROL
The emission control system employed with the
John
Deere 6090HF
diesel engine consist of a
Diesel Oxidation
Catalyst
(DOC) and a
Selective Catalytic Reduction
(SCR) catalyst as an exhaust gas after-treatment system
that helps reducing harmful gases and destroying the
organic fraction of the particulate matter produced from
the exhaust gas to meet the requirement for EPA Tier 4
Final regulations.
The DOC device (Figure 73) helps in filtering out large
amounts of harmful
Nitrogen Oxides
(NOx) and
Particulate
Matter
(PM) which are emitted by diesel engines. These
exhaust emissions pose serious environmental and health
risks. It is important to maintain and service the DOC
emission safety device on a periodic basis.
Diesel Oxidation Catalyst (DOC)
The DOC does not filter particles it oxidizes them. This
catalyst (honeycomb like structure) uses a chemical
process to break down pollutants in the exhaust stream
into less harmful components. In general, this catalyst
collects/burns accumulated particulates. The DOC contains
palladium and platinum which serve as a catalysts to oxidize
hydrocarbons and carbon monoxide.
EMISSION CARBON CHECK
Deposition of carbon (soot, unburned fuel) in the exhaust
pipe line and muffler could cause not only system derates
but also could lead to fires.
To reduce soot and unburned fuel, run the unit at rated
power until the exhaust gas becomes mostly colorless every
250 hours operation time. More carbon will be generated
when the unit operates at less then 30% of rated power. In
this case, perform the above procedures more frequently.
NOTICE
Applying a large load suddenly to the unit when the
carbon deposition is generated in the exhaust system
could produce sparks and will lead to abnormal
combustion. Therefore, apply load gradually and
observe the exhaust gas color during the process.
Figure 73. Diesel Oxidation Catalyst DOC)
