Gas burner for a cooktop

Abstract

A gas burner comprises a flame ring, a Venturi tube to feed said flame ring, and a gas injector having a nozzle with an orifice to inject a burnable gas in said Venturi tube to feed said flame ring, wherein a flow perturbation element is provided in a region between said orifice and a middle portion of said Venturi tube to impact the air-gas mixing.

1 . Gas burner ( 1 ) comprising a flame ring ( 2 ), a Venturi tube ( 3 ) to feed said flame ring ( 2 ) with air/gas mixture and a gas injector ( 4 ) having a nozzle ( 20 ,  30 ,  40 ,  50 ) with an orifice ( 10 ) to inject a burnable gas in said Venturi tube ( 3 ), characterized in that a flow perturbation element ( 22 ,  32 ,  42 ,  52 ) is provided in a region between said orifice ( 10 ) and a middle portion ( 17 ) of said Venturi tube ( 3 ) to impact the air-gas mixing. 
     
     
         2 . Gas burner according to  claim 1 , characterized in that said flow perturbation element ( 22 ,  32 ,  42 ,  52 ) is set outside of said Venturi tube ( 3 ) and between an inlet ( 6 ) of said Venturi tube and said orifice ( 10 ). 
     
     
         3 . Gas burner according to  claim 2 , characterized in that said flow perturbation element ( 22 ,  32 ,  42 ) is carried by said nozzle ( 20 ,  30 ,  40 ,  50 ). 
     
     
         4 . Gas burner according to  claim 1 , characterized in that said flow perturbation element ( 22 ,  32 ,  42 ,  52 ) comprises at least an upward projection of said nozzle extending beyond the exit of the orifice ( 10 ) in a vertical direction. 
     
     
         5 . Gas burner according to  claim 4 , characterized in that said flow perturbation element ( 22 ,  32 ,  42 ) comprises a planar wall ( 23 ) facing a central axis (A) of said orifice ( 10 ). 
     
     
         6 . Gas burner according to  claim 5 , characterized in that said nozzle ( 20 ,  30 ,  40 ,  50 ) is a single body with said projection ( 22 ,  32 ,  42 ). 
     
     
         7 . Gas burner according to  claim 1 , characterized in that said flow perturbation element ( 22 ,  32 ,  42 ,  52 ) is distanced from a central axis (A) of said orifice ( 10 ). 
     
     
         8 . Gas burner according to  claim 4  characterized in that the position of said perturbation element ( 22 ,  52 ) is given by:
   0.5* D<X< 5* D   
   0.5* D<Y< 4* D   
 Where: 
 D is the diameter of said orifice ( 10 ); 
 X is the height of a top edge ( 24 ,  54 ) of said perturbation element ( 22  , 52 ) with respect to the exit of said orifice ( 10 ); 
 Y is the distance of said perturbation element ( 22 ,  52 ) from said axis (A). 
 
     
     
         9 . Gas burner according to  claim 1 , characterized in that said flow perturbation element comprises a further perturbation element ( 32 ,  42 ). 
     
     
         10 . Gas burner according to  claim 9 , characterized in that the position of said further perturbation element ( 32 ,  42 ) is given by:
   0.5* D<X 2<5* D       0.5* D<Y 2<4* D     Where:   X 2  is the height of a further top edge ( 33 ,  43 ) of said further perturbation element ( 32 ,  42 ) with respect to said orifice ( 10 );   Y 2  is the distance of said further perturbation element ( 32 ,  42 ) from said axis (A).   
     
     
         11 . Gas burner according to  claim 9 , characterized in that said perturbation element ( 22 ) and said further perturbation element ( 32 ,  42 ) are on opposite sides with respect to said axis (A). 
     
     
         12 . Gas burner according to  claim 9  characterized in that said perturbation element ( 22 ) and said further perturbation element ( 32 ,  42 ) define a slot therebetween. 
     
     
         13 . Gas burner according to  claim 1 , characterized in that said Venturi tube ( 3 ) comprises a diffuser ( 16 ) having a divergent cross section along the gas flow direction to feed said flame ring ( 2 ) and in that said flow perturbation element ( 22 ,  32 ,  42 ,  52 ) is placed upstream of said divergent portion ( 16 ). 
     
     
         14 . Method of operating a gas burner ( 1 ) comprising a flame ring ( 2 ), a Venturi tube ( 3 ) to feed said flame ring ( 2 ) with air/gas mixture and a gas injector ( 4 ) having a nozzle ( 20 ,  30 ,  40 ,  50 ) with an orifice ( 10 ) to inject a burnable gas in said Venturi tube ( 3 ), by providing a flow perturbation element ( 22 ,  32 ,  42 ,  52 ) in a region between said orifice ( 10 ) and a middle portion ( 17 ) of said Venturi tube ( 3 ) to impact the air-gas mixing. 
     
     
         15 . Method according to  claim 14 , characterized in that said flow perturbation element ( 22 ,  32 ,  42 ) is carried by said nozzle ( 10 ) and that said nozzle is releasably connectable to a body ( 8 ) of said injector ( 4 ).