Inlet assembly for aftertreatment system

An aftertreatment system to treat exhaust gases exiting an engine, the aftertreatment system comprising:

• an inlet portion adapted to receive a flow of exhaust gases;
• a diesel oxidation catalyst (DOC) assembly in fluid communication with the inlet portion, the DOC assembly including:
• a first DOC:
• a second DOC disposed adjacent to the first DOC in a parallel configuration;
• a diffuser plate disposed between the inlet portion and the DOC assembly along an exhaust gas flow path, wherein the diffuser plate includes a body, the body including:
• a first section disposed in front of the first DOC, the first section defining a plurality of first holes, wherein each of the plurality of first holes has a first diameter, and wherein each of the plurality of first holes directs a portion of the flow of exhaust gases from the inlet portion towards the first DOC;
• and
• a second section disposed in front of the second DOC, the second section defining a plurality of second holes and an elliptical opening adjacent to the plurality of second holes, wherein each of the plurality of second holes has a second diameter that is different from the first diameter of each of the plurality of first holes, and wherein each of the plurality of second holes and the elliptical opening direct a portion of the flow of exhaust gases from the inlet portion towards the second DOC;
• a diesel particulate filter (DPF) assembly in fluid communication with and disposed downstream of the DOC assembly along the exhaust gas flow path;
• and
• a selective catalytic reduction (SCR) module in fluid communication with and disposed downstream of the DPF assembly along the exhaust gas flow path.

A method of treating exhaust gases exiting an engine using an aftertreatment system, the aftertreatment system including a diesel oxidation catalyst (DOC) assembly, the DOC assembly including a first DOC and a second DOC disposed adjacent to the first DOC in a parallel configuration, the method comprising:

• receiving, via an inlet portion of the aftertreatment system, a flow of exhaust gases within the aftertreatment system along a first direction;
• redirecting the flow of exhaust gases from the first direction to a second direction, wherein the first direction is orthogonal to the second direction;
• contacting the flow of exhaust gases with a diffuser plate of the aftertreatment system, wherein the diffuser plate is disposed between the inlet portion and the DOC assembly along an exhaust gas flow path, and wherein the diffuser plate includes a body, the body including:
• a first section disposed in front of the first DOC, the first section defining a plurality of first holes, wherein each of the plurality of first holes has a first diameter;
• and
• a second section disposed in front of the second DOC, the second section defining a plurality of second holes and an elliptical opening adjacent to the plurality of second holes, wherein each of the plurality of second holes has a second diameter that is different from the first diameter of each of the plurality of first holes;
• uniformly dividing, by each of the plurality of first holes, each of the plurality of second holes and the elliptical opening in the diffuser plate, the flow of exhaust gases into a first stream of exhaust gases and a second stream of exhaust gases;
• and
• flowing the first stream of exhaust gases through the first DOC and the second stream of exhaust gases through the second DOC.