Engine Exhaust After Treatment System Flashcards
Beginning in 2007, U.S Diesel engines were required to comply with more stringent emissions standards to reduce:
Soot (partially burned fuel)
Ash (partially burned oil)
Nitrogen oxide (NOx)
Emissions equipment and used by Cummins: ATD- DOC- DPF- SCR- DEF-
After treatment device Diesel oxidation catalyst Diesel particulate filter Selective catalyst reduction Diesel exhaust fluid
An exhaust canister, which replaced the typical muffler.
After treatment device (ATD)
ATD- An exhaust canister. Contains a _____ and _____.
Diesel oxidation catalyst (DOC) and Diesel particulate filter (DPF)
The DPF will trap _______, _____ and ____.
Particulate matter, soot and ash.
Soot accumulation in the DPF requires self cleaning through ____.
Regeneration
A catalytic converter that uses vaporized diesel exhaust fluid to reduce nitrogen oxide emissions.
Selective catalyst reduction
Diesel exhaust fluid (DEF) also known as: DEF, ____ ,or ___.
Urea or Ad-Blue
Diesel Exhaust Fluid = ____ % of urea and _____ water
32.5% urea and deionized water
DEF which breaks down into _____ (NH3) in a decomposition reactor through the process ______
Ammonia, hydrolysis
The NOx and ammonia pass into the ___ element where NOx is converted into harmless _____ and ______.
Selective catalyst reduction(SCR) Nitrogen gas (N2) and water vapor (h2o)
The high exhaust system temperature (hest) light indicates an active regeneration has been initiated and exhaust temps are elevated above normal levels. The HEST light will remain on until exhaust temperatures have dropped below _____
977 degrees F
525 degrees C
Diesel particulate filter lights (DPF)
On solid:
Flashing:
Flashing with amber check engine:
Flashing with red stop engine:
Solid- (low to medium levels of particulate build up. Vehicle requires regen but should be able to complete its mission before regen is performed.
Flashing-(medium to high levels of particulate build up). The vehicle requires a regen ASAP
Flashing with amber check engine: A DPF regen is required immediately.
Flashing with red stop engine:. as soon it is safe to do so, the vehicle should be stopped and remain shut down until serviced by Cummins dealer.
Passive regeneration
Initiate a DPF regeneration by switching to a more challenging duty cycle (such as highway driving for at least ___ min or pumping)
20 min
If the hest light is on and the vehicle speed has dropped below the threshold of ____ mph, the light will remain on until the vehicle speed increases ____mph back above the speed threshold and the regeneration process finishes.
5mph threshold
3mph above
