SCR muffler

Abstract

An SCR muffler retains the heat of a reducing agent, etc., supplying nozzle and an exhaust pipe, thereby preventing the reduction of the efficiency of an SCR catalyst purging nitrogen oxide (NOx) even at low temperatures and improving the durability of the reducing agent, etc., supplying nozzle. The SCRmuffler comprises an SCRcatalyst 1 for selectively reducing and purging nitrogen oxide (NOx) contained in exhaust gas; an exhaust pipe 2 that allows the exhaust gas to flow into the SCR catalyst; and a reducing agent, etc., supplying nozzle 3 that supplies a reducing agent or a reducing agent precursor to the exhaust gas. The reducing agent, etc., supplying nozzle 3 or the exhaust pipe 2 is of a heat-retaining double pipe structure.

1 . An SCR muffler which comprises: 
 an SCR catalyst for selectively reducing and purging nitrogen oxide (NOx) contained in exhaust gas;    an exhaust pipe that allows the exhaust gas to flow into the SCR catalyst; and    a reducing agent, etc., supplying nozzle that supplies a reducing agent or a reducing agent precursor to the exhaust gas,    characterized in that the reducing agent, etc., supplying nozzle is of a double pipe structure.    
     
     
         2 . The SCR muffler according to  claim 1 , characterized in that a heat retaining material is provided in between an inner pipe and an outer pipe that form the double pipe structure.  
     
     
         3 . The SCR muffler according to  claim 1 , characterized in that there is a space defined between an inner pipe and an outer pipe that form the double pipe structure.  
     
     
         4 . An SCR muffler which comprises: 
 an SCR catalyst for selectively reducing and purging nitrogen oxide (NOx) contained in exhaust gas;    an exhaust pipe that allows the exhaust gas to flow into the SCR catalyst; and    a reducing agent, etc., supplying nozzle that. supplies a reducing agent or a reducing agent precursor to the exhaust gas,    characterized in that the exhaust pipe is of a double pipe structure.    
     
     
         5 . The SCR muffler according to  claim 4 , characterized in that a heat retaining material is provided in between an inner pipe and an outer pipe that form the double pipe structure.  
     
     
         6 . The SCR muffler according to  claim 4 , characterized in that there is a space defined between an inner pipe and an outer pipe that form the double pipe structure.