Method and Apparatus for Cleaning Electrodes of a Fuel-Fired Burner of an Emission Abatement Assembly

Abstract

A method of operating a fuel-fired burner of an emission abatement assembly includes detecting a burner shutdown request. The method further includes adjusting an air-to-fuel ratio of an air/fuel mixture being supplied to the burner to a ratio greater than a stoichiometric ratio in response to the burner shutdown request. The method further includes advancing the adjusted air/fuel mixture to an electrode assembly of the burner for a predetermined amount of time in response to the burner shutdown request. The method further includes shutting down the burner after the predetermined period of time has elapsed. An associated emission abatement assembly is also disclosed.

1 . A method of operating a fuel-fired burner of an emission abatement assembly, the method comprising:
 detecting a burner shutdown request,   adjusting an air-to-fuel ratio of an air/fuel mixture being supplied to the burner to a ratio greater than a stoichiometric ratio in response to the burner shutdown request,   advancing the adjusted air/fuel mixture to an electrode assembly of the burner for a predetermined amount of time in response to the burner shutdown request, and   shutting down the burner after the predetermined period of time has elapsed.   
   
   
       2 . The method of  claim 1 , wherein advancing the adjusted air/fuel mixture comprises energizing the electrode assembly to combust matter accumulated thereon. 
   
   
       3 . The method of  claim 2 , wherein:
 the electrode assembly comprises a first electrode and a second electrode spaced apart from one another to define a gap, and   energizing the electrode assembly comprises applying power to at least one of the first electrode and the second electrode to generate a spark in the gap.   
   
   
       4 . The method of  claim 1 , wherein advancing the adjusted air/fuel mixture comprises advancing the adjusted air/fuel mixture to a flame of the burner to combust soot accumulated on the electrode assembly. 
   
   
       5 . The method of  claim 4 , wherein adjusting the air-to-fuel ratio further comprises moving the flame of the burner toward the electrode assembly. 
   
   
       6 . The method of  claim 5 , wherein the adjusting the air-to-fuel ratio comprises supplying oxygen to the exhaust gas to adjust the air-to-fuel ratio of the air/fuel mixture to a ratio greater than a stoichiometric ratio. 
   
   
       7 . An emission abatement assembly for an internal combustion engine, comprising:
 a particulate filter,   a fuel-fired burner positioned upstream of the particulate filter, the fuel-fired burner having an electrode assembly,   an electronically-controlled fuel delivery assembly operable to deliver fuel to the fuel-fired burner, and   a controller electrically coupled to the fuel-fired burner, the controller comprising (i) a processor, and (ii) a memory device electrically coupled to the processor, the memory device having stored therein a plurality of instructions which, when executed by the processor, cause the processor to:   detect a burner shutdown request,   operate, in response to the burner shutdown request, the fuel delivery assembly for a predetermined amount of time to adjust an air-to-fuel ratio of an air/fuel mixture being supplied to the electrode assembly of the burner to a ratio greater than a stoichiometric ratio, and   shut down the burner after the predetermined amount of time has elapsed.   
   
   
       8 . The emission abatement assembly of  claim 7 , wherein:
 the electrode assembly comprises a first electrode and a second electrode spaced apart from one another to define a gap, and   the plurality of instructions, when executed by the processor, further cause the processor to cease power to the first electrode and the second electrode after the predetermined period of time has elapsed.   
   
   
       9 . The emission abatement assembly of  claim 7 , further comprising an oxygen supply, wherein the controller is electrically coupled to the oxygen supply, wherein the plurality of instructions, when executed by the processor, further cause the processor to operate the oxygen supply to supply oxygen to adjust the ratio of the air-to-fuel ratio of the air/fuel mixture being supplied to the electrode assembly of the burner. 
   
   
       10 . The emission abatement assembly of  claim 9 , wherein the oxygen supply comprises an air pump. 
   
   
       11 . The emission abatement assembly of  claim 9 , wherein the oxygen supply comprises a turbocharger. 
   
   
       12 . The emission abatement assembly of  claim 7 , wherein the plurality of instructions, when executed by the processor, further cause the processor to operate the fuel delivery assembly to adjust an air-to-fuel ratio of an air/fuel mixture being supplied to the electrode assembly of the burner to a ratio greater than a stoichiometric ratio to move a flame of the burner toward the electrode assembly.