Flow Distributor For Engine Exhaust Aftertreatment Component

Abstract

An engine exhaust aftertreatment component includes a housing defining an exhaust flow from an exhaust inlet to an exhaust outlet. An exhaust aftertreatment substrate is positioned within the housing between the exhaust inlet and the exhaust outlet and has an upstream face, which includes an inner region surrounded by an outer region. A flow distributor is positioned in the housing upstream from the exhaust aftertreatment substrate and divides the exhaust flow into a first portion directed toward the inner region through a first set of perforations and a second portion directed toward the outer region serially through a second set of perforations and a third set of perforations.

What is claimed is: 
     
         1 . An engine exhaust aftertreatment component, comprising:
 a housing defining an exhaust flow from an exhaust inlet to an exhaust outlet;   an exhaust aftertreatment substrate positioned within the housing between the exhaust inlet and the exhaust outlet and having an upstream face, wherein the upstream face includes an inner region surrounded by an outer region; and   a flow distributor positioned in the housing upstream from the exhaust aftertreatment substrate, wherein the flow distributor divides the exhaust flow into a first portion directed toward the inner region through a first set of perforations and a second portion directed toward the outer region serially through a second set of perforations and a third set of perforations.   
     
     
         2 . The engine exhaust aftertreatment component of  claim 1 , wherein the flow distributor includes:
 a flow distribution conduit oriented along a longitudinal axis of the housing, extending from the exhaust inlet toward the inner region, and including the second set of perforations; and   a flow distribution plate oriented perpendicularly to the longitudinal axis and including the first and third sets of perforations.   
     
     
         3 . The engine exhaust aftertreatment component of  claim 2 , wherein the first and third sets of perforations define an axial flow direction, and the second set of perforations define a radial flow direction. 
     
     
         4 . The engine exhaust aftertreatment component of  claim 2 , wherein a flow rate per unit area at the inner region is of a same order of magnitude of a flow rate per unit area at the outer region. 
     
     
         5 . The engine exhaust aftertreatment component of  claim 4 , wherein a total flow area defined by a sum of the second set of perforations is greater than a total flow area defined by a sum of the first set of perforations. 
     
     
         6 . The engine exhaust aftertreatment component of  claim 5 , wherein the total flow area defined by the sum of the second set of perforations is greater than a total flow area defined by a sum of the third set of perforations. 
     
     
         7 . The engine exhaust aftertreatment component of  claim 4 , wherein a perimeter of an outlet opening of the flow distribution conduit matches a perimeter of the inner region. 
     
     
         8 . The engine exhaust aftertreatment component of  claim 7 , wherein a perimeter defined by a tangent to a peripheral set of perforations of the third set of perforations matches a perimeter of the upstream face. 
     
     
         9 . The engine exhaust aftertreatment component of  claim 4 , wherein an axial length of the flow distributor is less than a diameter of the exhaust inlet. 
     
     
         10 . The engine exhaust aftertreatment component of  claim 9 , wherein a diameter of the upstream face is about two times a diameter of the flow distribution conduit. 
     
     
         11 . The engine exhaust aftertreatment component of  claim 2 , wherein the exhaust aftertreatment substrate is coated in a diesel oxidation catalyst. 
     
     
         12 . A method of distributing exhaust flow in an engine exhaust aftertreatment component, the engine exhaust aftertreatment component including a housing defining an exhaust flow from an exhaust inlet to an exhaust outlet, an exhaust aftertreatment substrate positioned within the housing between the exhaust inlet and the exhaust outlet and having an upstream face, wherein the upstream face includes an inner region surrounded by an outer region, and a flow distributor positioned in the housing upstream from the exhaust aftertreatment substrate, the method comprising:
 dividing the exhaust flow into a first portion and a second portion using the flow distributor;   directing the first portion toward the inner region of the upstream face of the exhaust aftertreatment substrate through a first set of perforations; and   directing the second portion toward the outer region of the upstream face of the exhaust aftertreatment substrate serially through a second set of perforations and a third set of perforations.   
     
     
         13 . The method of  claim 12 , further including directing the first portion through a flow distribution conduit of the flow distributor and through the first set of perforations of a flow distribution plate of the flow distributor. 
     
     
         14 . The method of  claim 13 , further including directing the second portion into the flow distribution conduit, through the second set of perforations of the flow distribution conduit, and through the third set of perforations of the flow distribution plate. 
     
     
         15 . The method of  claim 14 , wherein directing the first portion through the first set of perforations and directing the second portion through the third set of perforations includes directing the first and second portions in an axial flow direction; and wherein directing the second portion through the second set of perforations includes directing the second portion in a radial flow direction. 
     
     
         16 . The method of  claim 13 , further including providing a flow rate per unit area at the inner region that is a same order of magnitude of a flow rate per unit area at the outer region. 
     
     
         17 . The method of  claim 16 , further including dimensioning and arranging the first and second sets of perforations such that a total flow area defined by a sum of the second set of perforations is greater than a total flow area defined by a sum of the first set of perforations. 
     
     
         18 . The method of  claim 17 , further including dimensioning and arranging the second and third sets of perforations such that a total flow area defined by the sum of the second set of perforations is greater than a total flow area defined by a sum of the third set of perforations. 
     
     
         19 . The method of  claim 12 , further including performing the dividing and directing steps along an axial length of the flow distributor that is less than a diameter of the exhaust inlet. 
     
     
         20 . The method of  claim 12 , further including directing the first and second portions through the exhaust aftertreatment substrate having a diesel oxidation catalyst coating.