Arrangement and method for treatment of exahust gases

Abstract

An exhaust gas treatment arrangement and a method thereof is contemplated for treating exhaust gases flowing along a flow path in an exhaust pipe system. The arrangement comprises a supply element being in communication with a source comprising an ammonia gas. The supply element comprises at least two discharge apertures being adapted to communicate with the flow path such that the ammonia gas may be dispersible from the discharge apertures into the exhaust gases in the flow path in at least two discharge directions.

1 . An exhaust gas treatment arrangement for treating exhaust gases flowing along a flow path in an exhaust pipe system, the arrangement comprising:
 a supply element being in communication with a source comprising an ammonia gas, said supply element comprising at least two discharge apertures being adapted to communicate with the flow path such that the ammonia gas is dispersible from the discharge apertures into the exhaust gases in the flow path in at least two discharge directions.   
     
     
         2 . The arrangement according to  claim 1 , wherein the supply element is adapted to be arranged on an outside of said exhaust pipe system. 
     
     
         3 . The arrangement according to  claim 1 , wherein the supply element is adapted to be arranged in said exhaust pipe system. 
     
     
         4 . The arrangement according to  claim 1 , wherein the supply element is ring-shaped. 
     
     
         5 . The arrangement according to  claim 1 , wherein the supply element is adapted to extend across said flow path. 
     
     
         6 . The arrangement according to  claim 1 , wherein each discharge aperture comprises at least one of an opening, a spray nozzle and a discharge head. 
     
     
         7 . The arrangement according to  claim 1 , further comprising a mixing unit for mixing air with the ammonia gas before said ammonia gas is dispersed into the exhaust gases. 
     
     
         8 . An exhaust pipe system comprising:
 an exhaust pipe; and   a supply element being in communication with a source comprising an ammonia gas, wherein the supply element via at least one gas inlet through a wall element in the exhaust pipe system leads the ammonia gas into said flow path.   
     
     
         9 . The exhaust pipe system according to  claim 8 , wherein the supply element comprises at least two discharge apertures being adapted to communicate with the flow path such that the ammonia gas is dispersible from the discharge apertures into the exhaust gases in the flow path in at least two discharge directions 
     
     
         10 . The exhaust pipe system according to  claim 9 , further comprising a catalytic converter having a first substrate and a second substrate arranged in said flow path between an inlet and an outlet of said catalytic converter, said second substrate being arranged upstream of said first substrate, wherein said discharge apertures are arranged in the flow path between said first substrate and said second substrate. 
     
     
         11 . The exhaust pipe system according to  claim 10 , wherein the catalytic converter comprises a SCR catalytic converter or a SCR coated substrate. 
     
     
         12 . The exhaust pipe system according to  claim 9 , wherein the discharge apertures with respect to each other, seen in a cross-section in the flow path, have a symmetrical arrangement in the flow path. 
     
     
         13 . The exhaust pipe system according to  claim 12 , wherein at least a first plurality of the discharge apertures with respect to each other, seen in a cross-section in the flow path, cause the ammonia gas to discharge towards a center of the flow path. 
     
     
         14 . The exhaust pipe system according to  claim 12 , wherein at least a second plurality of the discharge apertures with respect to each other, seen in a cross-section in the flow path, cause the ammonia gas to discharge away from the center towards a perimeter of the flow path. 
     
     
         15 . The exhaust pipe system according to  claim 9 , wherein the discharge apertures with respect to each other, seen in a cross-section in the flow path, cause the ammonia gas to discharge away from a center towards a perimeter of the flow path. 
     
     
         16 . The exhaust pipe system according to  claim 9 , wherein the discharge apertures with respect to each other, seen in a cross-section in the flow path, have a first number of discharge apertures diametrically opposed to a second number of discharge apertures, the first number of discharge apertures causing the ammonia gas to discharge in a direction diametrically opposed to the second number of discharge apertures. 
     
     
         17 . A method of treating exhaust gases flowing along a flow path in an exhaust pipe system comprising:
 discharging ammonia gas into said flow path from at least two discharge apertures in at least two discharge directions.   
     
     
         18 . The method according to  claim 17 , further comprising discharging the ammonia gas symmetrically in three discharge directions. 
     
     
         19 . The method according to  claim 17 , further comprising discharging the ammonia gas into said flow path upstream of a first substrate in a catalytic converter. 
     
     
         20 . The method according to  claim 17 , further comprising mixing the ammonia gas with air prior to discharging the ammonia gas into said flow path.