40VOLVOEngines
SelectiveCatalyticReduction(SCR)
SelectiveCatalyticReduction(SCR)isanemissions-reductiontechnologywiththeability
todelivernear-zeroemissionsofnitrogenoxides(NOx),asmog-causingpollutantand
greenhousegas.SCR'sperformancehasbeenprovedinmillionsofmilesofreal-worldtruck
operationsinothercountries,aswellasinlong-termeldtestsintheU.S.
SCRreducesNOxemissionstoverylowlevels,whileatthesametimedeliveringexcellent
fueleconomyandreliability.Thesystemdoesn'tchangethedesignoroperationofthebasic
engine.Rather,SCRisanaftertreatmentsystemwhichconvertsNOxintheexhauststream
intoharmlessgases.Moderndieselsalreadyuseexhaustaftertreatmentsystems,called
dieselparticulatelters,tocontrolemissionsofanotherpollutant,soot(alsoknownas
particulatematterorPM).
SCRworksbyinjectingDieselExhaustFluid(DEF)intotheexhauststeam,aftertheDPF.
DEFisasafe,simplesolutionofwaterandurea.DEFworkswiththeheatoftheexhaust
andacatalysttoconvertNOxintonitrogenandwatervapor-twoharmlessandnatural
componentsoftheairwebreathe.Theendresultiscleanerair,excellentfuelefciencyand
areliableemissionscontrolsystemfortoday'smoderndieselengine.
W2031651
1.DieselEngine
2.AftertreatmentDEFTank
3.AftertreatmentDEFPump
4.AftertreatmentDEFDosingUnit
5.AftertreatmentDieselParticulateFilter(DPF)
6.SelectiveCatalyticReduction(SCR)Catalyst
7.AftertreatmentDEFTankSendingUnitandDEFLowLevelIndicator