A burner includes a distal flame holder, first and second fuel nozzles, a fuel and oxidant source, and a mixing tube disposed upstream from the distal flame holder. Fuel emitted from the first fuel nozzle mixes with oxidant from the oxidant source to form a fuel and oxidant mixture to support combustion in the distal flame holder. A non-reactive fluid source such as recirculated flue gas provides a non-reactive fluid for dilution of the fuel and oxidant mixture to prevent flashback.

The invention relates to a premixing method for premixing fuel with air prior to the combustion of a fuel/air mixture to allow burners to be operated at high output and with a good load variation range with stable and reliable operation and low NOx emissions. The method comprises: a) creating a rich fuel/air mixture with a fuel/air ratio above an ignitable fuel/air ratio, b) supplying air to the rich fuel/air mixture to obtain an ignitable fuel/air mixture, and c) swirling the ignitable fuel/air mixture obtained in step a) or b). The invention further relates to a premixing device for performing the method.

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.

A reactor for a mixture of fluids that can react with each other exothermically, the reactor combining the properties of heat transfer and porosity, and having a first chamber wherein reacted fluids are maintained above the reaction temperature threshold, a second chamber disposed adjacent to the first chamber, wherein unreacted fluids enter the second chamber at a temperature that is below a reaction temperature threshold that is necessary for reaction of the fluids to occur, the fluids flowing in a second direction, opposite the first direction and a porous wall disposed between the first chamber and a second chamber, allowing portions of the unreacted fluids from the second chamber to seep into the reacted fluids of the first chamber, thereby heating the seeped fluids, causing the seeped fluids to react, the reaction increasing the temperature of the reacted fluid.

A combustion system includes a fuel distributor configured to output a fuel, an oxidant source configured to output an oxidant, and a mixing tube defining a mixing volume aligned to receive the fuel and oxidant. The mixing tube is shaped to convey the fuel and the oxidant through the mixing volume at a bulk velocity higher than a flame propagation speed. The combustion system includes a flame holder aligned to receive the mixed fuel and oxidant and to support a combustion reaction of the fuel and the oxidant.

A flue gas recirculation combustor includes a combustor chamber configured such that fuel and combustion gas are injected therein to cause combustion and having a nozzle-side end and a combustor outlet, a nozzle can connected to the nozzle-side end of the combustor chamber, a plurality of nozzles disposed in the nozzle can and configured such that an injection direction thereof is directed to a side of the combustor chamber, and a sleeve disposed in a premixing space defined between the nozzle can and the nozzle-side end of the combustor chamber, the sleeve including a recirculation pathway to recirculate combustion air from the combustor chamber to the premixing space.

The pre-mix burner assembly includes a jet pump comprising a suction chamber, a flue gas inlet, and a combustion air tube with a combustion air nozzle. The combustion air inlet includes a combustion air tube with a tapered nozzle, and it is connected to a combustion air fan. The flue gas inlet is connected to the suction chamber and the combustion air fan. The suction chamber surrounds the combustion air tube, and it has a jet pump nozzle with a discharge. The assembly includes a fuel gas inlet connected to the combustion air tube. The combustion air and fuel gas mixture exits the combustion air nozzle creating a negative pressure in the suction chamber and drawing flue gas into the suction chamber. The assembly includes a mixing tube positioned downstream of the jet pump discharge, and a burner block connected to an outlet of the mixing tube.

A refractory apparatus may include a refractory bock comprising a heat shield. The refractory block can include a group of flue gas ports that acts as a gateway for flue gas produced due to combustion downstream of a burner. A suction created in the burner drives the flue gas into the burner through the flue gas ports. A group of staged risers can be housed within the refractory block. The staged risers are protected in staged fuel riser housings in the refractory block. A discharge cone is located in the refractory block for flame stabilization in the burner.

A flame stabilization apparatus with fuel injection upstream of a torpedo, includes a flame stabilization plate that incorporates spokes that stabilize a flame over a range of operations of a burner. The spokes surrounds a fuel plenum with respect to the burner. A first group of fuel ports can be located in a fuel tube upstream of the torpedo and a second group of fuel ports can be located in the flame stabilization plate. A discharge cone includes a discharge zone for the burner, wherein the flame with respect to the flue gas is stabilized at an end of the burner in the discharge zone.

A combustion system includes a fuel distributor configured to output a fuel, an oxidant source configured to output an oxidant, and a mixing tube defining a mixing volume aligned to receive the fuel and oxidant. The mixing tube is shaped to convey the fuel and the oxidant through the mixing volume at a bulk velocity higher than a flame propagation speed. The combustion system includes a flame holder aligned to receive the mixed fuel and oxidant and to support a combustion reaction of the fuel and the oxidant.