Mixing device

Abstract

A mixing device for integrating into an exhaust pipe of an internal combustion engine and for intermixing an exhaust gas flow T, which device is formed by a housing including a pipe wall for guiding the exhaust gas in a main flow direction H, an intermediate wall which at least partially delimits a flow cross section Qs of the housing, and by a mixing pipe, wherein: the mixing pipe has an injection nozzle for an additive to be incorporated, the nozzle being in the region of a first end E1 of the mixing pipe, and the mixing pipe is accommodated, in the region of a second end E2, in the intermediate wall; a perforation zone having a through-flow cross section Qp is provided at least between the injection nozzle and the intermediate wall; the intermediate wall and the mixing pipe 5 separate the housing into an inflow sector and an outflow sector; at least 90% of the gas to be guided from the inflow sector to the outflow sector can be directed through the perforation zone; a wedge-shaped flow-directing element having a directing nose is provided after the mixing pipe, which nose protrudes beyond the pipe wall and/or the intermediate wall and by means of which the exhaust gas flow T can be divided into two partial flows T1, T2; and wherein the partial flows T1, T2 can be brought into a counter swirl flow in relation to the main flow direction H.

What is claimed is: 
     
         1 . A mixing device for integrating into an exhaust pipe of an internal combustion engine and for intermixing an exhaust gas flow T, comprising: a housing comprising a pipe wall for guiding the exhaust gas in a main flow direction H and an intermediate wall which at least partially delimits a flow cross section Qs of the housing and by a mixing pipe, wherein the mixing pipe has an injection nozzle for an additive to be incorporated in the region of a first end, and is accommodated in the region of a second end in the intermediate wall, wherein a perforation zone having a through-flow cross-section Qp is provided at least between the injection nozzle and the intermediate wall, wherein the intermediate wall and the mixing pipe separate the housing into an inflow sector and an outflow sector, wherein at least 90% of the gas to be guided from the inflow sector to the outflow sector can be directed through the perforation zone, wherein after the mixing pipe, a wedge-shaped flow directing element is provided with a directing nose which protrudes over the pipe wall and/or the intermediate wall, and by means of which the exhaust gas flow T can be divided into two partial flows T 1 , T 2 , wherein the partial flows T 1 , T 2  can be brought into a counter swirl in relation to the main flow direction H. 
     
     
         2 . The mixing device according to  claim 1 , wherein
 the mixing tube has an oval profile form F with a height h   running along a main axis and a breadth b   running along an auxiliary axis wherein the main axis is aligned   transverse to the main flow direction H of the exhaust gas flow, with
     h>= 1.2  b.    
   
     
     
         3 . The mixing device according to  claim 2 , wherein
 the following applies to the through-flow cross section Qp of the perforation zone   in relation to the flow cross section Qs of the housing:
   0. 05  Qs<=Qp<= 0.6  Qs  or 0.07  Qs<=Qp<= 0.5  Qs  or 0.08  Qs<=Qp<= 0.45  Qs.    
   
     
     
         4 . An exhaust pipe with an integrated mixing device according to  claim 1 . 
     
     
         5 . An exhaust system with an exhaust pipe according to  claim 4 . 
     
     
         6 . An exhaust pipe with an integrated mixing device according to  claim 2 . 
     
     
         7 . An exhaust pipe with an integrated mixing device according to  claim 3 . 
     
     
         8 . An exhaust system with an exhaust pipe according to  claim 7 .