Conical gas turbine burner having a fuel lance with inclined side nozzles

1. A burner useful in a gas turbine, the burner comprising:

a swirl generator;

a mixing tube downstream of the swirl generator;

wherein the swirl generator comprises at least two walls facing one another to define a substantially conical swirl chamber, the swirl generator comprising nozzles configured and arranged to inject a fuel and apertures configured and arranged to feed an oxidizer into said swirl chamber;

a lance which extends along a longitudinal axis of the swirl generator and comprises side nozzles configured and arranged to eject a fuel within the burner, the lance having a longitudinal axis;

wherein said lance side nozzles have axes inclined with respect to the lance longitudinal axis;

wherein said lance comprises a protrusion, wherein said lance side nozzles open within said mixing tube and the lance side nozzle axes extend towards said protrusion.

2. A burner as claimed in claim 1 , wherein said protrusion comprises an annular lip encircling said lance.

3. A burner useful in a gas turbine, the burner comprising:

a swirl generator;

a mixing tube downstream of the swirl generator;

wherein the swirl generator comprises at least two walls facing one another to define a substantially conical swirl chamber, the swirl generator comprising nozzles configured and arranged to inject a fuel and apertures configured and arranged to feed an oxidizer into said swirl chamber;

a lance which extends along a longitudinal axis of the swirl generator and comprises a lateral wall and side nozzles on said lateral wall, the side nozzles being configured and arranged to eject a fuel within the burner, the lance having a longitudinal axis;

wherein said lance side nozzles have axes inclined with respect to the lance longitudinal axis;

wherein said lance side nozzle axes are inclined less than 30° with respect to the lance longitudinal axis; and

wherein said lance comprises a body and an annular lid encircling the lance body, the lid and the body together defining an annular slit, wherein the lance side nozzles open in said annular slit.

4. A burner as claimed in claim 3 , wherein said lance side nozzles are positioned in a part of the lance which is housed within either the swirl generator or the mixing tube.

5. A burner as claimed in claim 3 , wherein said lance side nozzles axes extend towards said annular lid.

6. A burner as claimed in claim 3 , wherein said lance comprises a nozzle at its tip configured and arranged to inject fuel.

7. A burner as claimed in claim 6 , wherein said lance comprises a first pipe configured and arranged to feed the lance side nozzles and a second pipe configured and arranged to feed the tip nozzle, said first and second pipes being independently operable.

8. A burner as claimed in claim 3 , wherein said mixing tube comprises an end diffusion portion.

9. A burner as claimed in claim 8 , wherein said mixing tube comprises a contraction in a zone between a tip of the lance and a region of the lance provided with the side nozzles.

10. A burner as claimed in claim 3 , said swirl generator wall nozzles being divided into at least two independently operable nozzle groups.

11. A burner as claimed in claim 10 , wherein the at least two independently operable nozzle groups comprise a first nozzle group and a second nozzle group located downstream of the first nozzle group.

12. A sequential gas turbine comprising:

a plurality of burners positioned along a gas path, including a burner as claimed in claim 3 positioned as the first burner of said plurality of burners.

13. A burner as claimed in claim 3 , wherein said lance lateral wall is cylindrical.