US: Caterpillar to use downstream fuel injection to clear DPF soot

摘要

HEAVY-DUTY diesel engine manufacturer Caterpillar has revealed more about its next-generation ACERT (advanced combustion emissions reduction technology) system geared to achieve EPA 2007 legislation compliance. As well as incorporating cooled EGR for the first time, a catalytic diesel particulate filter (DPF) will become standard. Caterpillar says periodic active regeneration of the DPF - necessary when exhaust temperatures are too low for accumulated particulates (soot) to be oxidised by catalytically released NO_2 alone - will be accomplished through an injection of 'raw fuel' into the exhaust stream behind the turbocharger.