A system and method for reducing emissions from a boiler. A boiler generally has a combustion area. The system further includes a fuel pipe for delivering fuel. The system further includes a conduit. A bore extends through the conduit. The bore of the conduit is in fluid communication with the fuel pipe and the combustion area of the boiler. A pre-ignition source is positioned in the conduit. The pre-ignition source operates to pre-ignite at least a portion of the fuel flowing through the conduit.

A pre-ignition conduit for a pulverized fuel nozzle includes a duct having first and second opposing end portions, the first end portion configured to face an outlet of an igniter. The conduit further includes a cone-shaped concentrator for collecting and forwarding pulverized fuel into the duct for ignition, the cone-shaped concentrator being secured to the first end portion and located between the outlet of the igniter and the duct. The pre-ignition conduit functions as an ignition chamber within a pulverized fuel nozzle.

Embodiments of the present invention include high-temperature staged recirculating burners and radiant tube burner assemblies that provide high efficiency, low NOx and CO emissions, and uniform temperature characteristics. One such staged recirculating burner includes a combustion tube having inside and outside helical fins forming opposing spiral pathways for combustion gases and products of combustion, a combustion nozzle coupled to the combustion tube, a gas tube running axially into the combustion tube, and a staging gas nozzle coupled to the gas tube, where the staging gas nozzle includes radial exit holes into the combustion tube and an axial gas staging tube extending into the combustion nozzle to stage combustion.

Embodiments of the present invention include high-temperature staged recirculating burners and radiant tube burner assemblies that provide high efficiency, low NOx and CO emissions, and uniform temperature characteristics. One such staged recirculating burner includes a combustion tube having inside and outside helical fins forming opposing spiral pathways for combustion gases and products of combustion, a combustion nozzle coupled to the combustion tube, a gas tube running axially into the combustion tube, and a staging gas nozzle coupled to the gas tube, where the staging gas nozzle includes radial exit holes into the combustion tube and an axial gas staging tube extending into the combustion nozzle to stage combustion.

High turndown ratio gaseous fuel burner nozzles and the control thereof are provided. High turndown ratio gaseous fuel burner nozzles include a mechanically adjustable nozzle port, such as in the form of an iris port, for expanded turndown control. A nozzle extension longitudinally extending from the mechanical adjustable nozzle port can be included to assist in shaping the flow of combustible gas from the nozzle port. A laminar flow insert can be housed within the nozzle extension to assist in producing laminar flow of the combustible gas flowing therethrough. A burner nozzle controller in control communication with the mechanically adjustable nozzle port can adjust the size of the nozzle port to selectively maintain exit velocity of the gaseous fuel from the nozzle port for one or more of combustion stability and flame stability.

A method for decreasing nitrogen oxides of a pulverized coal boiler using burners of internal combustion type including during the operation of the boiler, ignition sources in the burners of internal combustion type mounted on side walls of the boiler are always in a working state, and igniting the pulverized coal in the burners in advance; decreasing secondary air amount in a primary combustion zone of the boiler so that the primary combustion zone is in a relatively strong reducing atmosphere and an oxygen-deficient condition for inhibiting generation of NOx is created; and supplying remaining air from an upper part of a furnace of the boiler in a form of over-fire air, so that a deep air staging is carried out in the total furnace. Thus, the NOx generation of combustion can be effectively controlled on the premise of not decreasing efficiency of the boiler.

A torch igniter includes an auxiliary fuel injector; an ignition source; and an igniter body carrying the auxiliary fuel injector and the ignition source. The igniter body includes an auxiliary combustion chamber having a side wall extending axially from a first end wall to a second end wall. In some examples, at least a portion of the side wall includes a distributed pattern of cooling apertures, with each of the cooling apertures extending obliquely from an outer surface of the side wall to an inner surface of the side wall. In some examples, the second end wall defines a fluid outlet leading to an outlet tube in fluid communication with the primary combustion chamber, at least a portion of the outlet tube including a distributed pattern of dilution apertures.

A torch igniter includes an auxiliary fuel injector; an ignition source; and an igniter body carrying the auxiliary fuel injector and the ignition source. The igniter body includes an auxiliary combustion chamber having a side wall extending axially from a first end wall to a second end wall, the side wall defining an interior cavity between the first and second end walls. The igniter body further includes a premixing cup residing within the interior cavity including a cylindrical wall radially surrounding the auxiliary fuel injector and an auxiliary air inlet, the cylindrical wall of the premixing cup protruding axially outward relative to the first end wall of the auxiliary combustion chamber through a portion of the interior cavity to delineate a premixing zone radially inward of the cylindrical wall and a recirculation zone radially outward of the cylindrical wall.

The present disclosure provides a burner for a reduction reactor, the reduction reactor has a reaction space formed therein, wherein each burner has a fuel feeding hole and multiple oxygen feeding holes formed therein, wherein each burner has an elongate combustion space formed at one end of a head portion thereof, the combustion space fluid-communicating with the reaction space of the reactor, wherein the elongate combustion space has a length such that oxygen supplied from the oxygen feeding holes thereto is completely consumed via oxidation or combustion with fuels supplied from the fuel feeding hole thereto only in the elongate combustion space upon igniting the burner.

An embodiment of a torch igniter for a combustor of a gas turbine engine includes a combustion chamber oriented about an axis, a cap defining an axially upstream end of the combustion chamber, a tip defining the axially downstream end of the combustion chamber, an igniter wall extending from the cap to the tip and defining a radial extent of the combustion chamber, a structural wall coaxial with and surrounding the igniter wall, an outlet passage defined by the igniter wall within the tip, a glow plug housing configured to receive a glow plug and allow an innermost end of the glow plug to extend into the combustion chamber, and a cooling system. The cooling system includes an air inlet formed within an exterior of the structural wall, a cooling channel forming a flow path through the structural wall at the glow plug housing, and an air passage.