Exhaust aftertreatment system for an engine

Abstract

An exhaust aftertreatment system for an engine operating within a range of stoichiometric and sub-stoichiometric air-fuel ratios (0.92<λ≤1) includes an exhaust passageway, and a first catalytic module that has an inlet disposed in fluid communication with the exhaust passageway for receiving exhaust from the exhaust passageway. The exhaust aftertreatment system also includes a first device for introducing an oxidant into the exhaust of the first catalytic module, and a second device for mixing the introduced oxidant with the exhaust of the first catalytic module. The exhaust aftertreatment system also includes a second catalytic module concentric with the first catalytic module such that heat transfer is facilitated between the first and second catalytic modules while exhaust is prevented from flowing radially between the first and second catalytic modules, and a means for diverting the exhaust from an outlet of the first catalytic module to an inlet of the second catalytic module.

Dependencies are inferred from the claim text.