DESCRIPTION AND OPERATION
Page 47
35
Figure 35 — DPF Non-Catalyzed System Diagram
In the non-catalyzed system (Figure 35),
compressed air and fuel combine with the
exhaust gases in an enclosed space. An
electrode ignites the mixture. This process also
quickly clears the filter. There is a separate
controller to manage the combustion cycling
based on the back pressure in the output stream.
At these temperatures, the process is rapid
(10–12 minutes).
As with passive regeneration, the process is not
complete. Remove the filters and physically
remove the remaining material using the special
machine for cleaning. The filters are reusable.
CONTINUOUS AIR PURGE SYSTEM
The purpose of the Continuous Air Purge System
(CAPS) is to purge any residual fuel left in the
aftertreatment fuel injector (AFI) to help prevent
carbon fouling after regeneration. Any time the
engine is running and regeneration is not taking
place, air is purged through the AFI. Air for
system operation is drawn from the chassis
secondary air system.
The CAPS system includes an in-line filter, a
chassis-mounted pressure regulator, an in-line
check valve and double check valve assembly
(CVA) mounted on the AFI. The pressure
regulator reduces chassis air pressure to the
approximately 32 psi level required for the air
purge system operation. The double check valve
assembly, which has both air and fuel ports,
directs the flow of air and fuel to the AFI while
preventing fuel from entering the air system and
air from entering the fuel system.
DISCHARGE RECIRCULATION VALVE
The discharge recirculation valve (DRV) redirects
some of the turbocharger output back through the
turbocharger. This results in elevated exhaust
temperature. The EECU uses this feature to
maintain adequate exhaust temperature in
support of active regeneration in the DPF system.
1. DPF Muffler
2. Muffler and Exhaust Stack
3. Temperature Sensors
4. Diesel Particulate Filter
5. Delta Pressure Differential Sensor
6. Combustion Chamber Assembly
7. Flex Pipe
8. Hose Clamp
9. Exhaust Pipe
10. Turbocharger
11. Inlet Manifold
12. Fuel Return
13. Fuel Supply
14. Air Tank
15. Fuel Pump
16. Atomization Block
17. Check Valve
18. Solenoid Valve
19. NOx Sensor
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