Aftertreatment device having an improved inlet cone

Abstract

An aftertreatment device is provided for purifying exhaust gases of an internal combustion engine for an automotive vehicle. The aftertreatment device includes a catalyst substrate and an inlet cone from which exhaust gases reach the catalyst substrate. The inlet cone includes a baffle accommodated inside the inlet cone and configured to realize a flow uniformity index, representing the percentage of utilized catalyst volume, higher than a flow uniformity index threshold.

1 - 5 . (canceled) 
     
     
         6 . An aftertreatment device for purifying exhaust gases of an automotive vehicle having an internal combustion engine, the aftertreatment device comprising a catalyst substrate and an inlet cone directing exhaust gases to the catalyst substrate, and a baffle accommodated inside the inlet cone and configured to realize a flow uniformity index (UI), which represents a percentage of utilized catalyst volume, higher than a flow uniformity index threshold (UI thr ). 
     
     
         7 . The aftertreatment device according to  claim 6 , wherein the flow uniformity index is defined as follows: 
       
         
           
             
               
                 U 
                  
                 
                     
                 
                  
                 I 
               
               = 
               
                 1 
                 - 
                 
                   
                     1 
                     
                       2 
                        
                       
                           
                       
                        
                       A 
                        
                       
                         V 
                         _ 
                       
                     
                   
                    
                   
                     ∫ 
                     
                       
                         ( 
                         
                           V 
                           - 
                           
                             V 
                             _ 
                           
                         
                         ) 
                       
                        
                       
                          
                         A 
                       
                     
                   
                 
               
             
           
         
         where: 
         UI=flow uniformity index; 
         A=surface of the first layer of cells in the catalyst substrate; 
         V=exhaust gas speed; and 
           V =exhaust gas average speed; and 
       
       the flow uniformity index threshold is 0.9. 
     
     
         8 . The aftertreatment device according to  claim 6 , wherein the baffle comprises a shaped metal sheet. 
     
     
         9 . The aftertreatment device according to  claim 6 , wherein the baffle comprises an inner cone. 
     
     
         10 . The aftertreatment device according to  claim 9 , wherein the inner cone is downscaled with respect to the inlet cone. 
     
     
         11 . The aftertreatment device according to  claim 9  wherein a cross section between the inlet cone and the inner cone is substantially the same width along a circumference. 
     
     
         12 . An internal combustion engine equipped with an aftertreatment device according to  claim 6 .