Aftertreatment system having a combined wall-flow and flow-through substrate

摘要

An exhaust aftertreatment system for a vehicle having an internal combustion engine. The aftertreatment system comprises a single substrate 600 with a plurality of exhaust gas channels. Some channels are open at both ends, and other channels have a porous surface and are plugged at one end. The substrate comprises an outer cone 650 having channels open at both ends, and an inner cone 670 having channels with a porous surfaces and plugged at one end. Exhaust gases are redirected from the outer cone to the inner cone. The outer cone may accommodate a flow-through diesel oxidation catalyst, and the inner cone may accommodate a wall-flow diesel particulate filter. The outer cone may also accommodate a flow-through ammonia clean up catalyst. The inner cone may also accommodate a selective catalytic reduction system.