16871-ZV7-000 Honda TUBE C, FUEL (Honda Code 4432225).

Illustration 1 g03536143
(1) CEM
(2) Air compressor
(3) Dosing control cabinet
(4) DEF main tank
(5) Engine
Illustration 2 g03410867
(1) CEM
(2) Dosing control cabinet
(3) DEF main tank
(4) Compressed air supply
(5) Air to air aftercooler
(6) Air cleaner
(7) Turbocharger compressor
(8) Turbocharger turbine
(9) Diesel Oxidation Catalyst (DOC)
(10) Mixing tube
(11) Selective Catalyst Reduction (SCR)
(12) Exhaust out Diesel Exhaust Fluid (DEF)
Note: A tool is available to measure the DEF concentration. The tool is the 360-0774 Refractometer.Selective Catalyst Reduction (SCR) refers to a method of treating engine exhaust in order to reduce the undesired oxides of nitrogen compounds NOx. SCR uses a catalyst which promotes a desired chemical reactions over other possible chemical reactions. The catalyst remains unchanged. Ammonia (NH3) is mixed into the exhaust, and reacts with the NOx in the presence of the catalyst to form harmless compounds (water and nitrogen). In this system, urea ((NH2)2CO) is injected into the exhaust, which quickly decomposes into ammonia under the heated conditions. Urea is used because urea is inexpensive, and does not need the special handling that ammonia requires.DEF is aqueous urea (urea salt dissolved in water).A 32.5 percent (by weight) solution of DEF is required for the system.A 32.5 percent concentration has the lowest freezing point possible, −11 °C (11 °F), for this solution.A 32.5 percent concentration of urea keeps a constant concentration through freezing and thawing.DEF must be stored below 50 °C (122 °F) to delay decomposition.Note: The customer is responsible for providing primary filtering of the DEF from the site tank to the main tank. The system requires a 40 micron primary filter.Use only DEF that meets quality properties per ISO 22241-1. Using DEF that does not meet ISO 22241-1 can result in clogging of the injection nozzle.Refer to Operation and Maintenance Manual, "Maintenance Section" in order to obtain locations for DEF suppliers.DEF is a non-toxic source of ammonia. A 32.5 percent concentration is slightly alkaline, having a pH of 9.5, similar to baking soda or soap. DEF is corrosive. Do not store DEF in a tank or use supply lines that are made of the following materials: aluminum, brass and steel. Use only corrosion resistant materials such as PVC or stainless steel. Any O-rings must be Ethylene Propylene Diene Monomer (EPDM).Clean Emissions Module (CEM) for Progress Rail
Illustration 3 g03536316
Internal view of the CEM for the 3500 engine
(1) Treated exhaust leaving the CEM
(2) SCRs
(3) Mixing tube
(4) DOC CEM Operation
The aftertreatment system for the exhaust combines the following technologies:
Selective Catalyst Reduction (SCR)
Diesel Oxidation Catalyst (DOC)The SCR reduces NOx.The DOC reduces the following:
Carbon monoxide
Hydrocarbons
Soluble organic fractionThe DOC and SCR are packaged together in a module. The module is called the Clean Emissions Module (CEM). Exhaust gas enters into the CEM through the inlet housing and passes through the DOC.The exhaust gas then enters the mixing tube, where the DEF is injected into the exhaust stream.The DEF decomposes into ammonia and carbon dioxide.The mixture of exhaust and ammonia travels through the SCR.The ammonia reacts with the NOx in the exhaust stream at the SCR catalyst to produce water vapor and nitrogen.Dosing Control Cabinet
Illustration 4 g03539539
Dosing control cabinet
(1) Dosing control cabinet
(2) SCR system ECM
(3) DEF pump
(4) DEF manifold The dosing control cabinet controls the following:
Rate of DEF flow to the injector
Compressed airCompressed air is used for the following:
Assist in the atomizing of the liquid DEF during injection into the exhaust stream
Shield the liquid DEF in the injector from the exhaust heat until spraying, so that no crystallization occurs which could plug the injection nozzle.
Purge the DEF line to the injector during shutdown in order to prevent crystallization of DEF resulting in a plug.Compressed Air Supply to Dosing Cabinet
The air provided to the dosing cabinet needs to be dry and clean. An oil-less air compressor is required.Oil can foul the catalyst and prevent the necessary chemical reactions from occurring. Sediment in the airline can plug the injection system.
Table 1
Aftertreatment Air Supply Specification
Air Quality Class 5
Oil content – maximum 25 mg/m3
Particle size – maximum 40 micron
Particle density – maximum 10 mg/m3
Relative air humidity – maximum 10%
Air flow capacity – minimum 9 SCFM / 255 L/min
Air pressure – minimum 60 psi / 414 kPag
Air pressure – maximum 150psi / 1034 kPag The SCR system will use up to 255 L/min (9 SCFM) at 414 kPag (60 psi). The system contains an air regulator with a maximum rating of 1034 kPa (150 psi) inlet pressure.To avoid clogging the air system with oil and/or sediment from piping, use a coalescing filter/separator that is 90 percent effective rated for 1034 kPa (150 psi) and 849.5 L/min (30 CFM).Air lines must be sized and routed so pressure loss across the line is no greater than 1.0 psi with air delivery at 50 psi and 5 CFM.Dosing Control System
The purpose of the dosing control system is to meter DEF into the exhaust stream.The dosing control cabinet houses an Electronic Control Module (ECM) that provides the basic logic.The desired rate of DEF injection is determined via a closed loop system, utilizing NOx sensors for feedback. The sensors measures the level of nitrogen oxide in the exhaust gas exiting the SCR.If the NOx sensor indicates high NOx in the exhaust outlet, the closed loop system will request an increase of the DEF flow rate.DEF flow rate is increased by increasing the duty cycle of the command signal to the dosing pump.The aftertreatment ECM controls the duty cycle of the command signal to the dosing pump. A communication adapter plug is provided on the side of the dosing control cabinet for easy connection.Injector
Injector Assembly