Superheated urea injection for aftertreatment applications

Abstract

An urea SCR system for enhancing internal combustion engine aftertreatment applications includes a supply tank containing aqueous urea, a delivery pump operatively connected to the supply tank and configured for elevating the pressure of aqueous urea drawn from said supply tank. The urea SCR system further includes a conduit arrangement connecting the delivery pump to an injection nozzle which is positioned adjacent an exhaust stream, the conduit arrangement being configured for the delivery of aqueous urea to the injection nozzle. Downstream of the delivery pump and upstream from the injection nozzle, a heating element is positioned for preheating of the aqueous urea to a superheated condition prior to injection into the exhaust stream.

1 . An urea SCR system for enhancing internal combustion engine aftertreatment applications, said urea SCR system comprising: 
 a supply of urea solution;    delivery means for delivering urea solution into an exhaust stream at an injection location; and    heating means positioned between said supply of urea solution and said injection location for preheating urea solution prior to injection into said exhaust stream.    
   
   
       2 . The urea SCR system of  claim 1  which further includes a delivery pump flow coupled to said supply of urea solution.  
   
   
       3 . The urea SCR system of  claim 2  which further includes an injection nozzle adjacent said injection location.  
   
   
       4 . The urea SCR system of  claim 3  wherein said heating means includes a glow plug.  
   
   
       5 . The urea SCR system of  claim 4  wherein said preheating corresponds to a superheated condition for said urea solution.  
   
   
       6 . The urea SCR system of  claim 5  wherein said exhaust stream includes a catalyst and said injection location is upstream of said catalyst.  
   
   
       7 . The urea SCR system of  claim 1  which further includes an injection nozzle adjacent said injection location.  
   
   
       8 . The urea SCR system of  claim 1  wherein said heating means includes a glow plug.  
   
   
       9 . The urea SCR system of  claim 1  wherein said heating means includes a glow plug.  
   
   
       10 . The urea SCR system of  claim 1  wherein said exhaust stream includes a catalyst and said injection location is upstream of said catalyst.  
   
   
       11 . The urea SCR system of  claim 1  wherein said urea solution is a mixture of water and urea.  
   
   
       12 . An urea SCR system for enhancing internal combustion engine aftertreatment applications, said urea SCR system comprising: 
 a container holding a supply of aqueous urea;    a delivery pump operatively connected to said container;    a conduit connecting said delivery pump to an injection nozzle for delivery of aqueous urea to said injection nozzle; and    a heating element acting on aqueous urea in said conduit for elevating the temperature of said aqueous urea prior to injection into an exhaust stream by way of said injection nozzle.    
   
   
       13 . The urea SCR system of  claim 12  wherein said heating element is a glow plug.  
   
   
       14 . The urea SCR system of  claim 13  wherein said elevating of the temperature of said aqueous urea raises said temperature to a superheated condition.  
   
   
       15 . The urea SCR system of  claim 14  wherein said exhaust stream includes a catalyst and the location of said injection nozzle defines an injection location, said injection location being upstream of said catalyst.  
   
   
       16 . The urea SCR system of  claim 12  wherein said elevating of the temperature of said aqueous urea raises said temperature to a superheated condition.  
   
   
       17 . The urea SCR system of  claim 12  wherein said exhaust stream includes a catalyst and the location of said injection nozzle defines an injection location, said injection location being upstream of said catalyst.