Patent ID: 8292615

Claim:
A burner for burning non-premixed gaseous fuel and air with low NOx emissions, said burner comprising: an outer tube configured to supply combustion air, and being terminated by a conically converging section; an inner gaseous fuel tube configured to supply gaseous fuel gas to the combustion, and being positioned concentrically inside the outer tube; and a burner head disposed at the end of the inner gaseous fuel tube, and having a conical part, the burner head being a downstream diverging cone, wherein the conical part of the burner head has a series of circumferentially arranged primary orifices through which a major portion of the gaseous fuel is capable of exiting into an annular space between the outer tube and an upstream end of the burner head, the burner head also having a secondary inlet for gaseous fuel at a free end of the conical part, the secondary inlet configured to introduce a minor part of the gaseous fuel to the burning zone and wherein the burner head protrudes a predetermined distance from an end of the conically converging section of the outer tube.