Exhaust gas temperature reduction device for aftertreatment devices

Abstract

A motor vehicle exhaust system has at least a first housing for a pollution control element, a nozzle in the housing and a ventilation path into the housing through which outside air is drawn into the exhaust system for mixing with an exhaust flow following the nozzle.

1 . Apparatus comprising:
 a housing having an inlet, an outlet and defining a channel for a fluid from the inlet to the outlet;   a bulb having a hollow interior with the bulb located in the channel and having a closed end defining an upstream end of the bulb in the channel and an open end defining a downstream end of the bulb, the bulb being disposed in the channel to constrict the flow of a fluid in the channel;   at least a first opening through the housing; and   the bulb being mounted from the housing by at least a first wing conduit, said at least first wing conduit being connected between said first opening and hollow interior of the bulb.   
   
   
       2 . Apparatus as claimed in  claim 1 , further comprising:
 a second wing opening in the housing; and   a second wing conduit connecting the bulb to the housing, the second wing conduit being hollow and providing fluid communication between the hollow interior of the bulb and outside of the housing through the second opening.   
   
   
       3 . Apparatus as claimed in  claim 2 , further comprising:
 the bulb being located in the channel to position its open end to discharge into the outlet and to not occupy a substantial portion of the channel upstream from the bulb.   
   
   
       4 . An exhaust system for a motor vehicle engine comprising:
 a treatment system for a vehicle exhaust stream including a plurality of housings disposed along an exhaust pipe, the exhaust pipe and housings defining a conduit; and   a ventilation path for drawing ambient air into the vehicle exhaust stream at a point of discharge from at least a first housing to cool the vehicle exhaust, the ventilation path including a bulb mounted within said at least first housing to constrict the conduit within the housing, the bulb having a hollow interior, mounts between the bulb and the housing to fix the position of the bulb, channels through the mounts fluidically connecting the hollow interior to outside of the housing, the bulb having an open downstream end to allow fluid communication between the hollow interior and the conduit.   
   
   
       5 . An exhaust system for a motor vehicle in accordance with  claim 4 , further comprising:
 the open downstream end of the bulb being located to discharge into the exhaust pipe.   
   
   
       6 . An exhaust system for a motor vehicle in accordance with  claim 5 , the bulb being generally rounded and enclosed at an upstream end. 
   
   
       7 . An exhaust system for a motor vehicle in accordance with  claim 6 , the housing containing a diesel particulate filter subject to high temperature regeneration. 
   
   
       8 . An exhaust system for a motor vehicle in accordance with  claim 7 , the bulb and interior of the housing defining a venturi for promoting mixing of an exhaust stream with outside air drawn through the bulb downstream from the venturi. 
   
   
       9 . A motor vehicle comprises an exhaust system having at least a first housing for a pollution control element, a nozzle in the housing and a conduit defining a ventilation path into the housing through which outside air is drawn into the exhaust system for mixing with an exhaust flow, the conduit having an orifice discharge from the ventilation path into the exhaust system after the nozzle. 
   
   
       10 . A motor vehicle in accordance with  claim 9 , wherein the nozzle is formed in ring arcs between the housing and the conduit.