A dry low NO.sub.X staged combustion system includes a fuel nozzle and a combustion compartment. The fuel nozzle includes a purge gas tube, a diffusion combustion fuel tube, an isolation gas tube, a premixed combustion fuel tube, a premixed combustion air tube. The purge gas tube is configured to feed a purge gas. The diffusion combustion fuel tube is fitted over the purge gas tube, and having an end provided with a diffusion combustion fuel swirler. The isolation gas tube is fitted over the diffusion combustion fuel tube. The premixed combustion fuel tube is fitted over the isolation gas tube. The premixed combustion air tube is fitted over the premixed combustion fuel tube. The combustion compartment is located downstream of the fuel nozzle.

A flare gas burner and a process for disposing of a waste gas using such a burner. The burner has a rounded outer surface that includes a plurality of dimples. The dimples increase the mixing of the waste gas and ambient air prior to combustion. The flare gas burner may have a diameter of 0.61 m and between 300 and 400 dimples. The flare gas burner may comprise a cast material.

A combustor for a gas turbine is provided. The combustor includes a pre-combustion chamber having a center axis and a swirler which is mounted to the pre-combustion chamber. The swirler surrounds the pre-combustion chamber in a circumferential direction with respect to the center axis. The swirler has a bottom surface which forms a part of a slot through which oxidant/fuel mixture is injectable into the pre-combustion chamber, wherein the bottom surface is located in a bottom plane. The swirler further includes a fuel injector which is arranged to the bottom surface such that a fuel is injectable into the slot with a fuel injection direction, wherein a first component of the fuel injection direction is non-parallel to the normal (n) of the bottom plane.

A nozzle, a combustor, and a gas turbine, which are capable of atomizing fuel efficiently, are provided. A fuel injection device for the combustor may include a plurality of guide channels connected to a pilot fuel passage through which fuel is supplied, an injection chamber connected to the plurality of guide channels, the fuel being merged in the injection chamber, and an injection hole formed at a tip of the injection chamber to inject the fuel, and the injection chamber may include a decompression space to drop a pressure therein.

A burner apparatus and method of operating the burner apparatus include a burner housing, and a group of fuel and air swirlers maintained by the burner housing, with the group of fuel and air swirlers supplied by a common fuel and air source. The fuel and air can be directed to one or more of the fuel and air swirlers at a time. Each fuel and air swirler among the group of fuel and air swirlers can mix the fuel and the air, resulting in a combustible mixture of the fuel and the air downstream of the group of fuel and air swirlers. The burner apparatus be implemented as a low NOx multi-port burner apparatus.

A fuel injector is disclosed for reducing flashback. In an embodiment, the fuel injector may comprise an injector head with purge holes on a radial wall along a radial axis between an assembly axis of the fuel injector and a plurality of vanes arranged circumferentially around the assembly axis. In addition, the plurality of vanes may comprise fuel outlets connecting interior fuel passages to spaces between the vanes. The introduction of these purge holes near the bases of the vanes and the configuration and positioning of the fuel outlets in the vanes and elsewhere in the fuel injector may alter the stoichiometry (e.g., fuel-air ratio) within the premix passage of the fuel injector to reduce flashback. A plurality of such fuel injectors may be used in the combustor of a gas turbine engine.

Emissions of NO.sub.X and/or CO are reduced at the stack by systems and methods wherein a primary fuel is thoroughly mixed with a specific range of excess combustion air. The primary fuel-air mixture is then discharged and anchored within a combustion chamber of a burner. Further, the systems and methods provide for dynamically controlling NO.sub.X content in emissions from a furnace by adjusting the flow of primary fuel and of a secondary stage fuel, and in some cases controlling the amount or placement of combustion air into the furnace.

The fuel nozzle for the gas turbine includes a radial swirler and an axial swirler. The radial swirler is arranged to swirl a first flow of a first oxidant-fuel mixture and the axial swirler is arranged to swirl a second flow of a second oxidant-fuel mixture. The first flow may be fed by a central conduit and the second flow may be fed by an annular conduit surrounding the central conduit.

A premixed low-nitrogen gas boiler is provided, which includes a reversed flow-swirl mixer being opposite mixing of natural gas and air. A flow deflector is arranged at a gas mixture outlet of the reversed flow-swirl mixer. An upper flow equalizing plate and a lower flow equalizing plate are arranged below the flow deflector, the upper flow equalizing plate is positioned above the lower flow equalizing plate, and a channel for enhancing mixing of gas mixture is formed between the upper flow equalizing plate and the lower flow equalizing plate. A comb-shaped water-cooled burner is arranged at the rear end of the lower flow equalizing plate, a combustion chamber is arranged at the rear end of the comb-shaped water-cooled burner, hearth tube bundles are arranged in a ladder-shaped convergent hearth, and the hearth tube bundles form an inner loop with a working medium water-steam mixture in a hearth water tank.

An air and gas feeder device for gas boilers, comprising an air-gas conveyance body which comprises: a boiler coupling face configured to be coupled to a boiler at an intake duct of the boiler; an air intake port connected to an air discharge opening by means of an air passage, the air discharge opening leading out from the boiler coupling face; a gas intake port, configured to be fixed to a gas dispensing duct in fluid communication with a gas discharge opening, which leads out from the boiler coupling face; wherein the air discharge opening is coaxial to, and at least partially surrounded by, the gas discharge opening; the air passage accommodates a flow diverter configured to divert an air flow in output from the air discharge opening in the direction of the gas in output from the gas discharge opening and to impart a rotation to said air flow.