Inlet for exhaust treatment device

An exhaust gas treatment device for treating an exhaust flow from an engine, the exhaust gas treatment device comprising:

• an inlet housing having an inlet opening for receipt of the exhaust flow from the engine, the inlet opening being aligned along a first axis;
• a main housing including a cylindrical body portion defining a treatment zone and an exhaust outlet aligned along a second axis extending parallel to the first axis, the inlet housing being in fluid communication with and fixed to an outer surface of the main housing, the inlet housing including a contoured wall including an end portion positioned opposite the inlet opening and an aperture extending through the wall transverse to the first axis, wherein a portion of the contoured wall opposite the aperture includes a radially outwardly sloping portion intersecting a radially inwardly sloping portion at an inflection point, the inflection point being positioned axially downstream from the inlet opening and upstream from an upstream edge of the aperture to redirect the exhaust flow through the aperture;
• and
• a component coupled to the main housing for treating exhaust flowing through the treatment zone.