TRACK GP 1134190 - Caterpillar

Engine Rear Gear Train
Illustration 5 g00268312
(1) Crankshaft
(2) Large cluster idler
(3) Small cluster idler
(4) Camshaft
(5) Idler
Table 4
Rear Gear Train For C280 Series Engines
Gear Number Of Teeth
(1) Crankshaft 81
(2) Large Cluster Idler 90
(3) Small Cluster Idler 45
(4) Camshaft 81
(5) Idler 81 Aftertreatment Reference Weights
Table 5
Approximate Weights Of Aftertreatment System Components for C280-16 Engine
Aftertreatment Components Weight
SCR reactor housing (CEM)(1)(2) 1765 kg (3891 lb)
Single catalyst assembly 21.5 kg (47.3 lb)
Service/access door 24 kg (53 lb)
Mixing pipe(3) 145.5 kg (320.7 lb)
DEF injector lance assembly 6.35 kg (14 lb)
Dosing cabinet 125 kg (275.6 lb)
(1) Without catalyst assemblies
(2) Single reactor housing
(3) 457 mm (18 inch) diameter mixing pipeAftertreatment System Description
Illustration 6 g03498661
Typical aftertreatment system. Caterpillar supplied aftertreatment components are illustrated with dashed line rectangles. The aftertreatment system supplied may be different than the illustration shown.
Selective Catalyst Reduction (SCR) catalyst technology is used to reduce NOx emissions and particulate matter (PM).The aftertreatment system is composed of the following components:
Diesel Exhaust Fluid (DEF)
Dosing cabinet
Mixing tube
SCR reactor housings (CEM) (2)
SCR catalystsDEF fluid is injected into the exhaust stream before entering the SCR. When injected into the exhaust stream, the DEF is atomized into droplets. The atomized droplets are then sent through the mixer. The mixer disrupts the exhaust flow and allows DEF to be distributed throughout the exhaust gas. Water evaporates due to the high temperature of the exhaust and releases ammonia (NH3) that was bound to the DEF. NH3 is free to react with the NOX and the oxygen present in the exhaust system stream. This reaction occurs on the SCR catalyst. NH3 and NOX are converted into gas particles of nitrogen and water.Dual SCR reactor housings (CEM)
Specific Installations may require dual SCR systems. Installations with dual SCR systems, each CEM, and dosing system operate independently. A single engine with dual SCR systems shares control and monitoring data via dual data links in parallel. Be sure to note and mark which CEM corresponds to each monitoring data set on electronic displays. Consult your Cat dealer to configure your vessels displays with customer-selected names for each independent SCR system.Engine exhaust flows into both SCR System reactor housings through the exhaust inlet. Once sufficient temperature is achieved, the DEF is injected into the exhaust. Exhaust flows through a mixer assembly in the mixing tube to ensure that exhaust is stratified for uniformity. This mixing will ensure complete disbursement across SCR catalyst section. Precise DEF injection is monitored and controlled by an electronic controller