Swirl jet burner

Abstract

A burner includes a combustor having a generally cylindrical, hollow shape extending along a centerline, and a closed end. A fuel tube that is connectable to a fuel supply has at least one opening fluidly connecting an interior of the combustor with the fuel source such that fuel can be delivered from the fuel source into the interior of the combustor. At least one air inlet disposed to provide an air stream into the interior of the combustor. The air stream is arranged and configured to create a vortex flow structure within the combustor.

We claim: 
     
         1 . A burner, comprising:
 a combustor having a generally cylindrical, hollow shape extending along a centerline, and a closed end;   a fuel tube that is connectable to a fuel source and having at least one opening fluidly connecting an interior of the combustor with the fuel source such that fuel can be delivered from the fuel source into the interior of the combustor;   at least one air inlet disposed to provide an air stream into the interior of the combustor, the air stream arranged and configured to create a vortex flow structure within the combustor.   
     
     
         2 . The burner of  claim 1 , wherein the combustor is configured to maintain the vortex flow structure through a length of the combustor along the centerline such that fuel from the fuel tube is mixed with the air stream, and to deliver a swirling mixture of air and fuel from an open end of the combustor. 
     
     
         3 . The burner of  claim 1 , further comprising a converging nozzle disposed at an open end of the combustor opposite the closed end. 
     
     
         4 . The burner of  claim 1 , wherein the at least one air inlet is disposed to inject the air stream in a tangential direction relative to a circular cross section of the combustor adjacent the closed end, such that the air stream has momentum components in both a radial direction and an axial direction with respect to the centerline. 
     
     
         5 . The burner of  claim 1 , further comprising an additional air inlet providing an additional air stream into the combustor. 
     
     
         6 . The burner of  claim 1 , wherein the fuel tube is disposed in the combustor and extends generally concentrically along the combustor. 
     
     
         7 . The burner of  claim 1 , wherein the fuel tube is disposed to inject fuel into the combustor in a tangential direction with respect to a circular cross section of the combustor. 
     
     
         8 . The burner of  claim 7 , wherein the air stream and the fuel are provided in opposing directions into the interior of the combustor. 
     
     
         9 . The burner of  claim 1 , further comprising an air distribution manifold having an air inlet opening in fluid communication with an air distribution passage, the air distribution passage being fluidly open to the at least one air inlet. 
     
     
         10 . The burner of  claim 9 , wherein the air distribution manifold has a generally hollow cylindrical shape disposed around the combustor adjacent the closed end, the air distribution manifold forming internally an annular passage extending around the combustor and surrounding a central ring, and wherein the at least one air inlet is formed as a straight passage extending through the central ring between the annular passage and the interior of the combustor. 
     
     
         11 . The burner of  claim 10 , wherein a second straight passage defining a second air inlet is formed in the central ring, the second straight passage being oriented in parallel with the at least one air inlet and disposed at an offset therewith such that the at least one air inlet and the second straight passage are both opposingly tangential at an offset relative to a circular cross section of the combustor. 
     
     
         12 . The burner of  claim 11 , wherein the at least one air inlet is disposed between 70°-80° with respect to the air inlet opening and the second straight passage is disposed between 100°-110° with respect to the air inlet opening around a periphery of the combustor. 
     
     
         13 . The burner of  claim 1 , further comprising a shroud disposed around an open end of the combustor opposite the closed end. 
     
     
         14 . The burner of  claim 13 , wherein the shroud has a generally cylindrical shape and forms a plurality of openings that are axially aligned with the open end of the combustor. 
     
     
         15 . The burner of  claim 14 , further comprising a collar being slidably selectively disposed along the shroud, wherein the collar is configured to cover at least partially each of the plurality of openings. 
     
     
         16 . The burner of  claim 1 , wherein the burner includes one or two pairs of opposed air inlets, each pair of air inlets being disposed in parallel and at an offset distance such that each air inlet provides the air stream in a tangential direction with respect to a circular cross section of the combustor. 
     
     
         17 . The burner of  claim 1 , wherein the combustor forms an open end opposite the closed end, the open end including an outlet opening formed at an end of a converging nozzle. 
     
     
         18 . A method for operating a burner, comprising:
 providing a combustor having a generally hollow cylindrical shape defining a closed end and an open end, the combustor defining an interior volume therein;   injecting at least one stream of air into the interior volume in a direction that is tangential to a circular cross section of the combustor adjacent the closed end;   inducing a swirling flow of the at least one stream of air into the combustor;   providing a flow of fuel into the combustor such that the flow of fuel mixes with the swirling flow of the at least one stream of air to form a swirling flow of a combustible mixture;   expelling the swirling flow of the combustible mixture from the open end of the combustor; and   when the swirling flow of the combustible mixture is burning, admitting at least a portion of combustion products created by the combustible mixture back into the swirling flow of the combustible mixture as the combustible mixture is expelled from the combustor.   
     
     
         19 . The method of  claim 18 , wherein the flow of fuel is provided through a fuel tube extending along the interior volume of the combustor. 
     
     
         20 . The method of  claim 18 , wherein the flow of fuel is provided as a stream tangentially into the interior volume with respect to the circular cross section of the combustor adjacent the closed end.