Definitions of Aftertreatment (ATS) Terms

sd mm 49.01.002

Note: Diagrams of ATS configurations are provided later in this chapter. For Detroit Diesel, see Fig., Fig., and Fig.. For Cummins, see Fig., Fig., and Fig..

Refer to the following list of definitions of ATS terms and components.

  • Aftertreatment System (ATS)—the entire exhaust system from the turbocharger to the exhaust stack or tail pipe.

  • Aftertreatment Device (ATD)—a housing that contains the DOC and DPF.

  • BlueTec®—Daimler's proprietary SCR technology.

  • Diesel Oxidation Catalyst (DOC)—a flow through device located at the ATD inlet that enhances the oxidation of hydrocarbons in order to reduce particulate emissions.

  • Diesel Particulate Filter (DPF)—a device installed on a diesel engine system that captures and reduces particulate matter (PM) from the exhaust gas.

  • Diesel Exhaust Fluid (DEF)—the chemical agent that reacts with the exhaust gases in the SCR to reduce NOx.

  • DEF Pump—filters and supplies DEF to the DEF metering unit.

  • DEF Tank—holds DEF and regulates its temperature.

  • DEF Metering Unit—mixes DEF with compressed air, and meters this mixture into the exhaust flow via an injection nozzle.

  • SCR Catalyst—the housing containing a treated ceramic flow-through block where the DEF and exhaust gases undergo selective catalytic reduction (SCR).

  • Selective Catalytic Reduction (SCR)—a process used to reduce NOx emissions.

Note: The sensor box (item 8) contains the SCR inlet and outlet NOx sensors, DPF outlet pressure sensor, and the DOC inlet pressure sensor.

Fig. 1, Detroit Diesel One-Box ATS (with Sensor Locations)

  1. DEF Metering Unit

  2. DEF Nozzle

  3. SCR Outlet Temperature Sensor

  4. SCR Inlet Temperature Sensor

  5. DOC Inlet Temperature Sensor

  6. DOC Inlet Pressure Sensor

  7. DPF Inlet Temperature Sensor

  8. DPF Outlet Pressure Sensor

  9. DPF Outlet Temperature Sensor

  10. DPF Outlet NOx Sensor

  11. SCR Outlet NOx Sensor

Fig. 2, Detroit Diesel 2V2 Two-Box ATS (with Sensor Locations)

  1. DPF Inlet Temperature Sensor

  2. DOC Inlet Temperature Sensor

  3. DOC Inlet Pressure Sensor

  4. DPF Sensor Box

  5. DPF Outlet Pressure Sensor

  6. DPF Outlet Temperature Sensor

  7. DPF Outlet NOx Sensor

  8. SCR Inlet Temperature Sensor

  9. DEF Metering Unit

  10. SCR Outlet Temperature Sensor

  11. SCR Sensor Box

  12. SCR Outlet NOx Sensor

Fig. 3, Detroit Diesel 2V2 Two-Box ATS (with Sensor Locations)

  1. ATD

  2. Mixer Tube

  3. DEF Injector

  4. NOx Sensor

  5. SCR Outlet Temperature Sensor

  6. SCR Inlet Temperature Sensor

  7. SCR Catalyst

  8. DOC Inlet Temperature Sensor

  9. DPF Inlet Temperature Sensor

  10. DPF Inlet Pressure Sensor

  11. DPF Outlet Temperature Sensor

  12. DPF Outlet Pressure Sensor

Fig. 4, Cummins Switchback Understep ATS (with Sensor Locations)

  1. ATD

  2. DOC Inlet Temperature Sensor

  3. DPF Inlet Temperature Sensor

  4. DPF Outlet Temperature Sensor

  5. DEF Injector

  6. NOx Sensor

  7. SCR Outlet Temperature Sensor

  8. SCR Catalyst

  9. SCR Inlet Temperature Sensor

  10. Mixer Tube

  11. DPF Outlet Pressure Sensor

  12. DPF Inlet Pressure Sensor

Fig. 5, Cummins 2HH ATS (with Sensor Locations)

  1. ATD

  2. NOx Sensor

  3. SCR Catalyst

  4. DPF Outlet Pressure Sensor

  5. DPF Inlet Pressure Sensor

  6. DEF Injector

  7. Mixer Tube

  8. SCR Inlet Temperature Sensor

  9. SCR Outlet Temperature Sensor

  10. DOC Inlet Temperature Sensor

  11. DPF Inlet Temperature Sensor

  12. DPF Outlet Temperature Sensor

Fig. 6, Cummins Switchback 2V2 ATS (with Sensor Locations)

Note:
Parent topic: EPA10 and Newer Exhaust System
Document Number: 0000120094
Manual Publication Date: 2024-05-23
Topic Publication Date: 2024-10-30