High perimeter stability burner

Abstract

Herein a gas boiler burner ( 1 ) is described comprising a diffuser, suitable for diffusing premixed fuel gases in a combustion chamber, in which the diffuser comprises a diffuser central portion ( 10 ) and two diffuser longitudinally peripheral portions ( 5 ), the two diffuser longitudinally peripheral portions ( 5 ) being connected together through the- central diffuser portion ( 10 ), the central diffuser portion ( 10 ) extending longitudinally in a direction perpendicular to the flow of the fuel gases over a length l greater than zero and having transversal cross- sections shaped as a circumference arc having a uniform radius of curvature r, each of the diffuser longitudinally peripheral portions ( 5 ) being shaped as a portion of a sphere having radius r.

What is claimed is: 
     
         1 . Burner for gas boiler comprising a diffuser, suitable for diffusing premixed fuel gases in a combustion chamber, each cross-section of said diffuser having a uniform radius of curvature, wherein said diffuser comprises a diffuser central portion and two diffuser longitudinally peripheral portions, said two diffuser longitudinally peripheral portions being connected together through said diffuser central portion, said diffuser central portion longitudinally extending in a direction perpendicular to the fuel gas flow for a length l greater than zero and having a cross-section being shaped as a circumference arc having a radius r, each of said diffuser longitudinally peripheral portions being shaped as a portion of sphere having radius r. 
     
     
         2 . Burner according to  claim 1 , further comprising a distributor, associated to the diffuser suitable for distributing fuel gases on the diffuser, having a shape substantially equal to that of the diffuser. 
     
     
         3 . Burner according to  claim 2 , wherein said distributor comprises a metal sheet provided with openings or a metal net or a porous material. 
     
     
         4 . Burner according to  claim 1 , wherein said diffuser comprises a mesh made of metal or ceramic fibres or of a compact material having openings or a porous material. 
     
     
         5 . Burner according to  claim 1 , wherein the diffuser is connected to a frame substantially perpendicular to the flow direction of the fuel gas.