Burner And Method For The Regeneration Of Filtration Cartridges And Devices Equipped With Such Burner

Abstract

A burner for heating a filter cartridge for the exhaust gases of an engine until the oxidation and/or combustion of the solid particulates trapped in the cartridge, including a burner body having a closed end and, on the side opposite this closed end, an opening for removing the said gases. The burner further including at least one intake duct for a mixture of fuel and oxidiser terminating in the burner body tangentially to the burner body, so as to cause the mixture to swirl in the burner; an electrical ignition means for igniting the said mixture positioned inside the burner body; and a closure element obstructing the burner body, to limit the turbulence of the exhaust gases in the volume of the burner body bounded by the said closure element.

1 . A burner for heating at least one filter cartridge for the exhaust gases of an internal combustion engine at a temperature above the oxidation temperature and/or the combustion temperature of the solid particulates trapped in the filter cartridge, said burner comprising:
 a burner body having side walls, a closed end side and having on a side opposite the closed end side a discharge opening suitable for connection to a duct for removing the exhaust gases;   at least one intake duct for a mixture of fuel and oxidiser terminating in the burner body in a direction essentially tangential to the burner body, so as to apply a swirl motion to the mixture inside the burner body;   an electrical ignition means for igniting the mixture, positioned inside the burner body; and   a closure element obstructing a substantial portion of the burner body, so as to limit turbulence that may be generated by the exhaust gases on fluid flows within a volume of the burner body bounded by the closure element.   
   
   
       2 . The burner according to  claim 1 , wherein an inner surface of the side walls of the burner body is uniform and has an overall symmetry of revolution about an axis of revolution. 
   
   
       3 . The burner according to  claim 2 , wherein the closure element comprises a disc having a diameter slightly smaller than an inside diameter of the burner body, and positioned perpendicular to the axis of revolution, on the closed end side of the burner body. 
   
   
       4 . The burner according to  claim 3 , wherein the disc is perforated with a plurality of holes, whereof at least one of a number and diameters are proportional to the diameter of the disc, the holes being intended for propagating a combustion flame of the mixture throughout the volume of the burner body. 
   
   
       5 . The burner according to  claim 3 , wherein the closure element further comprises a straight cylinder whereof one end is covered by the disc and whereof an opposing end is covered by the closed end of the burner body, the straight cylinder being perforated with a plurality of holes, whereof at least one of a number and diameters are proportional to the diameter of the disc, the holes being configured for propagating a combustion flame of the mixture throughout the volume of the burner body. 
   
   
       6 . The burner according to  claim 2 , wherein the closure element consists of a shutter placed outside the volume of the burner body near the discharge opening, an area of the shutter corresponding substantially to an internal area of the burner body, the shutter being mounted movably under an action of a member. 
   
   
       7 . The burner according to  claim 1 , further comprising two concentric lines, one for the fuel and the other for the oxidiser, the lines being placed upstream of the duct. 
   
   
       8 . The burner according to  claim 2 , wherein the mixture intake duct consists of a pipe extending along the side walls inside the burner body and parallel to the axis of revolution, the pipe having one end bent at a right angle. 
   
   
       9 . The burner according to  claim 1 , further comprising a second electrical ignition means positioned inside the burner body, the first and the second electrical ignition means consisting of a conventional heater plug and a conventional electric arc plug or of at least two heater plugs. 
   
   
       10 . The burner according to  claim 1 , further comprising a second intake duct for a mixture of fuel and oxidizer terminating in the burner body in a direction essentially tangential to the burner body, so as to apply a symmetrical swirl motion to the mixture inside the burner body. 
   
   
       11 . The burner according to  claim 1 , further comprising a control device for controlling an injection flow rate of the oxidiser and fuel according to signals delivered by a temperature sensor located in the burner body and by a pressure sensor indicating a pressure drop due to a clogging of the filter cartridge by the solid particulates. 
   
   
       12 . The burner according to  claim 1 , wherein the oxidiser is air from a turbocharger mounted on the engine. 
   
   
       13 . The burner according to  claim 1 , wherein a ceramic textile, in a form of at least one of a mat, fabric and felt, is placed on the closed end side of the burner body and in contact with at least one electrical ignition means, the ceramic textile being suitable for collecting and for concentrating the mixture in order to promote its ignition. 
   
   
       14 . The burner according to  claim 1 , wherein it comprises, at the side wall partly defining said burner, one or more through orifices, terminating in the burner body above the closure element intended for introducing part of the exhaust gases into the body. 
   
   
       15 . The burner according to  claim 14 , wherein at least one of the through orifices is prolonged inside the burner by a line, whereof an end is curved and pointed towards the closure element. 
   
   
       16 . An exhaust line of an internal combustion engine, comprising:
 at least one inlet orifice for the gases issuing from the internal combustion;   at least one filter cartridge for trapping the solid particulates contained in the exhaust gases of the engine;   at least one orifice for discharging the gases to the atmosphere, located downstream of the filter cartridge; and   at least one burner according to  claim 1 .   
   
   
       17 . The exhaust line according to  claim 16 , wherein the burner is placed upstream of the filter cartridge, at a location inside the exhaust line, outside the exhaust line, or near the filter cartridge. 
   
   
       18 . The exhaust line according to  claim 16 ,
 further comprising:
 at least two filter cartridges, the burner being accommodated between the two filter cartridges; and 
 two shutters for stopping the exhaust gas flows respectively reaching each filter cartridge, so as to burn and/or oxidise the particulates alternately in each filter cartridge. 
   
   
   
       19 . The exhaust line according to  claim 16 , further comprising a flap foldable on an outside wall of the burner, in order to cause the introduction of part of the exhaust gases thereinto. 
   
   
       20 . A method for heating at least one filter cartridge for the exhaust gases of an internal combustion engine at a temperature above the oxidation temperature and/or the combustion temperature of the solid particulates trapped in the filter cartridge, by means of a burner comprising a burner body having a symmetry of revolution, the burner body having a closed end and having on the side opposite the closed end a discharge opening suitable for connection to a duct for removing the exhaust gases;
 said method consisting of:
 injecting, in a direction essentially tangential to the burner body, a mixture of fuel and oxidiser, so as to apply a swirl motion to the mixture inside the burner body; 
 supplying electricity to an electrical ignition means positioned inside the burner body, in order to ignite the mixture, the burner body comprising a closure element obstructing a substantial portion of the burner body, so as to limit the turbulence that may be generated by the exhaust gases on fluid flows within the volume of the burner body bounded by the closure element; 
 interrupting the mixture injection after the oxidation temperature and/or the combustion temperature has(have) been reached during a period depending on parameters such as a load withstood by the engine and a pressure drop due to a clogging of the filter medium by these solid particulates. 
   
   
   
       21 . The method according to  claim 20 , wherein the fuel and the oxidiser are mixed in stoichiometric proportions. 
   
   
       22 . A machine for regenerating the filter cartridges of particulate filters, wherein it comprises a burner according to  claim 1  and a site for accommodating at least one filter cartridge to be regenerated.