Exhaust system and process for operating the same

Abstract

A process for operating an exhaust gas system comprises: producing an exhaust gas flow, introducing the exhaust gas flow to a system comprising a restricting device in fluid communication with an exhaust emission control device, and an exhaust conduit comprising an exhaust throttle device, restricting the flow of the exhaust gas stream to the restricting device, and discharging the exhaust gas stream from the restricting device into the exhaust emission control device. The flow is sufficiently restricted such that the exhaust gas stream discharged into the exhaust emission control device has a temperature perform a desired function selected from the group consisting of regeneration and light-off.

What is claimed is:  
     
         1 . A process for operating an exhaust gas system, comprising: 
 producing an exhaust gas flow;    introducing the exhaust gas flow to a system comprising a restricting device in fluid communication with an exhaust emission control device, and an exhaust conduit comprising an exhaust throttle device;    restricting the flow of the exhaust gas stream to the restricting device; and    discharging the exhaust gas stream from the restricting device into the exhaust emission control device;    wherein the flow is sufficiently restricted such that the exhaust gas stream discharged into the exhaust emission control device has a temperature perform a desired function selected from the group consisting of regeneration and light-off.    
     
     
         2 . The process for operating an exhaust gas system according to  claim 1 , wherein the flow is restricted when an engine producing the exhaust gas stream is operating at idle.  
     
     
         3 . The process for operating an exhaust gas system according to  claim 1 , wherein the flow is restricted based upon a vacuum level produced from the flow of the exhaust gas stream through the exhaust conduit.  
     
     
         4 . The process for operating an exhaust gas system according to  claim 1 , further comprising unrestricting the flow of the exhaust gas stream through the exhaust conduit when an engine producing the exhaust gas stream is operating under a load.  
     
     
         5 . The process for operating an exhaust gas system according to  claim 4 , further comprising producing the exhaust gas stream, and wherein the load is greater than or equal to about 20% of a maximum load for the engine.  
     
     
         6 . The process for operating an exhaust gas system according to  claim 1 , further comprising restricting the flow at timed intervals.  
     
     
         7 . The process for operating an exhaust gas system according to  claim 1 , further comprising producing the exhaust gas stream, sensing an operating load of the engine, and restricting the flow based upon the operating load.  
     
     
         8 . The process for operating an exhaust gas system according to  claim 1 , further comprising sensing an exhaust stream temperature at an inlet of the exhaust emission control device and restricting the flow based upon the exhaust stream temperature.  
     
     
         9 . The process for operating an exhaust gas system according to  claim 1 , wherein the restricting device and the exhaust gas conduit are separate conduits.  
     
     
         10 . The process for operating an exhaust gas system according to  claim 1 , wherein the exhaust gas conduit is in fluid communication with a second emission control device and the restricting device is only in fluid communication with the exhaust emission control device.  
     
     
         11 . The process for operating an exhaust gas system according to  claim 1 , wherein the exhaust emission control device is selected from the group consisting of catalytic converters, scrubbing devices, particulate filters/traps, adsorbers, and absorbers.  
     
     
         12 . An exhaust system, comprising: 
 a restricting device disposed in an exhaust conduit and in fluid communication with a exhaust emission control device; and    a second emission control device disposed in fluid communication with the exhaust conduit and downstream from the exhaust throttle device.    
     
     
         13 . The system according to  claim 12 , wherein the restricting device is a control conduit having a cross-sectional area less than or equal to about 50% of a cross-sectional area of the exhaust conduit.  
     
     
         14 . The system according to  claim 13 , wherein the control conduit cross-sectional area is less than or equal to about 40% of the cross-sectional area of the exhaust conduit.  
     
     
         15 . The system according to  claim 14 , wherein the control conduit cross-sectional area is less than or equal to about 30% of the cross-sectional area of the exhaust conduit.  
     
     
         16 . The system according to  claim 15 , wherein the control conduit cross-sectional area is less than or equal to about 20% of the cross-sectional area of the exhaust conduit.  
     
     
         17 . The system according to  claim 13 , wherein the control conduit and the exhaust conduit are separate conduits.  
     
     
         18 . The system according to  claim 17 , wherein the control conduit further comprises an inlet extending at or beyond a plane defined by the shutter portion.  
     
     
         19 . The system of  claim 13 , wherein the control conduit and the exhaust conduit comprise a single conduit with a divider disposed therein.  
     
     
         20 . The system according to  claim 12 , wherein the exhaust conduit further comprises an exhaust throttle device comprising a shutter portion.  
     
     
         21 . The system according to  claim 20 , wherein the control conduit is disposed within the exhaust gas conduit and is formed by a partition disposed in the exhaust conduit, with the shutter portion disposed on a side of the partition opposite the control conduit.  
     
     
         22 . The system according to  claim 21 , wherein the partition at least partially extends through the exhaust emission control device.  
     
     
         23 . The system according to  claim 20 , wherein the shutter further comprises at least one blade pivotable about a pivot point.  
     
     
         24 . The system according to  claim 20 , wherein the shutter portion further comprises an actuator, a support member and a blade, and wherein the actuator is in operable communication with the blade.  
     
     
         25 . An exhaust system, comprising: 
 an exhaust conduit in fluid communication an outlet of an engine and with a exhaust emission control device;    a means for restricting flow in the exhaust conduit under selected conditions; and    a means for controlling the means for restricting flow.