Exhaust aftertreatment unit

Abstract

An exhaust aftertreatment unit for cleaning exhaust gases, the exhaust aftertreatment unit including a fluid channel for providing a fluid pathway for the exhaust gases, the fluid channel having an outer casing; a catalyst casing housing a selective catalyst reduction (SCR) catalyst and an ammonia slip catalyst (ASC) arranged downstream of the SCR catalyst, the catalyst casing being arranged inside the outer casing forming an intermediate space between the inner and outer casings; and a detector configured to measure ammonia and/or NOx in the exhaust gases; wherein the catalyst casing includes one or more perforations upstream of the ASC to enable a by-pass flow of exhaust gases from inside the catalyst casing into the intermediate space, and wherein the detector is arranged in the fluid channel to measure the ammonia and/or NOx in the exhaust gases including the by-pass flow.

Dependencies are inferred from the claim text.