Device and method for post-treatment of exhaust gases of an internal combustion engine

Abstract

An exhaust gas treatment device has a cylindrical body with axial passages having a catalyst and a central cavity. A filter is provided in the cavity and the cylindrical body is mounted for rotation in a housing through which the exhaust gas flows.

In the claims:  
     
         1 . Apparatus for treatment of exhaust gases of an internal combustion engine comprising a housing having a gas inlet and a gas outlet and a chamber arranged between said inlet and said outlet, a gas permeable body at least partially coated with a catalyst for reduction of pollutant gases, and arranged for rotation in said chamber about an axis transverse to a direction corresponding to flow of gas between said inlet and said outlet, said gas permiable body having a central cavity having a filter arranged therein, said gas permeable body being arranged in said chamber such that gases entering said gas inlet flow through a first region of said body, through said filter in said central cavity and through a second region of said body to said gas outlet.  
     
     
         2 . Apparatus as specified in    claim 1    wherein said gas inlet of said housing is in flow communication with channels in said first region of said body.  
     
     
         3 . Apparatus as specified in    claim 1    wherein said filter is arranged to rotate with said body.  
     
     
         4 . Apparatus as specified in    claim 1    wherein said body has a cylindrical shape and includes radially extending gas flow channels.  
     
     
         5 . Apparatus as specified in    claim 4    wherein said cavity comprises a cylindrical recess extending along the axis of said cylindrical body.  
     
     
         6 . Apparatus as specified in    claim 1    further including a heating element.  
     
     
         7 . Apparatus as specified in    claim 1    wherein said body is arranged to rotate about a cylindrical axis within said housing.  
     
     
         8 . Apparatus as specified in    claim 7   , wherein said housing is made of a nonmetallic material.  
     
     
         9 . Apparatus as specified in    claim 1    wherein said body is rotated by a drive unit.  
     
     
         10 . Apparatus as specified in    claim 9   , wherein said drive unit is an electric motor.  
     
     
         11 . Apparatus as specified in    claim 9   , wherein said drive unit is formed by providing an magnetic field and magnets arranged within the housing.  
     
     
         12 . Apparatus as specified in    claim 1    wherein said body is arranged to rotate a speed of about 0.3 to 10 rpm.  
     
     
         13 . Apparatus as specified in    claim 1    wherein said body comprises ceramic.  
     
     
         14 . Apparatus as specified in    claim 1    wherein said body is fabricated using metal.  
     
     
         15 . Apparatus as specified in    claim 1    wherein said body is a monolith.  
     
     
         16 . Apparatus as specified in    claim 1    wherein said body comprises segments that are traversed by channels.  
     
     
         17 . Apparatus as specified in    claim 1    further including an inlet for the introduction of additional fuel.  
     
     
         18 . Apparatus as specified in    claim 17    wherein said inlet apparatus for the introduction of additional fuel is arranged at the axis of rotation of the body.  
     
     
         19 . A method for post-treatment of an exhaust gust gas stream of an internal combustion engine comprising: 
 providing a body having a catalyst in portions thereof and having a cavity with a filter; passing said exhaust gas through channels in a first region of said body, through said filter and through channels a second region of said body whereby soot particles are retained in said filter; and    rotating said body to interchange said first and second regions of said body.    
     
     
         20 . A method as specified in    claim 19    wherein said body is rotated at a speed which causes a maximum temperature region of said body to be located at said filter thereby to cause combustion of said soot particles.  
     
     
         21 . A method as specified in    claim 19    wherein reducing agents are added to cause continuous reduction of Nox accumulation in said body.  
     
     
         22 . A method as specified in    claim 19    further providing desulfurigation of said body, comprising periodically increasing the pollutant quantity of supplied exhaust gas and retarding or interrupting rotation of said body until a maximum temperature region is in said second region, and wherein said body is thereafter rotated so that second region assumes the original position of said first region and said maximum temperature region is predominantly in said repositioned first region and thereafter reducing the pollutant quantity.  
     
     
         23 . Method according to    claim 22   , wherein said retardation or interruption of rotation is repeated a number of times, until said body is substantially desulfurized.  
     
     
         24 . Method according to    claim 22   , wherein that continuous rotation of said body is resumed when the temperature maximum is located at approximately the interface of the first and second regions.