A burner supporting primary and secondary combustion reactions may include a primary combustion reaction actuator configured to select a location of the secondary combustion reaction. A burner may include a lifted flame holder structure configured to support a secondary combustion reaction above a partial premixing region. The secondary flame support location may be selected as a function of a turndown parameter. Selection logic may be of arbitrary complexity.

Generally described, a heating device, or heating tube, includes a combustive fluid inlet, respectively a combustible fluid inlet, is connected to a combustion head via a first pipe, respectively a second pipe, the second pipe being housed at least partially in the first pipe. In this heating device, the combustion head is distant of at least 50 cm from the combustible fluid inlet, which enables to create a “cold zone” between the two. The first and the second pipes enable to bring the combustible fluid and the combustive fluid separately to the combustion head, even if the latter is remote by at least 50 cm from the combustible fluid and combustive fluid inlets.

A perforated flame holder and burner including a perforated flame holder provides reduced oxides of nitrogen (NOx) during operation. The perforated flame holder includes a pattern of elongated apertures extending between a proximal and a distal surface of the flame holder relative to a fuel nozzle. The perforated flame holder can provide a significantly reduced flame height while maintaining heat output from the burner.

Generally described, a heating device, or heating tube, includes a combustive fluid inlet, respectively a combustible fluid inlet, is connected to a combustion head via a first pipe, respectively a second pipe, the second pipe being housed at least partially in the first pipe. In this heating device, the combustion head is distant of at least 50 cm from the combustible fluid inlet, which enables to create a cold zone between the two. The first and the second pipes enable to bring the combustible fluid and the combustive fluid separately to the combustion head, even if the latter is remote by at least 50 cm from the combustible fluid and combustive fluid inlets.

A furnace inducer choke and a gas furnace employing the furnace inducer choke. In one embodiment, the furnace inducer choke includes: (1) a choke body configured to engage a furnace inducer blower, the choke body having an opening extending entirely therethrough to limit an amount of combustion air entering a furnace that the furnace inducer blower is attached, and (2) a tab protruding from the choke body a distance sufficient to identify the opening when the choke body and furnace inducer blower are installed in the furnace.

A furnace inducer choke and a gas furnace employing the furnace inducer choke. In one embodiment, the furnace inducer choke includes: (1) a choke body configured to engage a furnace inducer blower, the choke body having an opening extending entirely therethrough to limit an amount of combustion air entering a furnace that the furnace inducer blower is attached, and (2) a tab protruding from the choke body a distance sufficient to identify the opening when the choke body and furnace inducer blower are installed in the furnace.

Methods and devices for combusting a carbonaceous fuel in an oxy-combustion fluidized bed reactor involving controlling the local oxygen content within the oxy-combustion reactor to specified levels. The carbonaceous fuel and an oxygen-containing gas are introduced into a fluidized bed reactor and eluted through a fluidized bed of an inert material, dolomite or a combination thereof to combust the fuel and oxygen to produce at least CO.sub.2 and steam. The oxygen-containing gas is a mixture of oxygen, recycled CO.sub.2 and steam and has sufficient oxygen added to the recycled CO.sub.2 and steam that the mixture contains 7-20 mole % oxygen. The carbonaceous fuel and the oxygen-containing gas are introduced into the fluidized bed at a location in sufficiently close proximity to each other to avoid producing a reducing atmosphere at the location. At least a portion of the produced CO.sub.2 and steam are recycled to the reactor.

A furnace inducer choke and a gas furnace employing the furnace inducer choke. In one embodiment, the furnace inducer choke includes: (1) a choke body configured to engage a furnace inducer blower, the choke body having an opening extending entirely therethrough to limit an amount of combustion air entering a furnace that the furnace inducer blower is attached, and (2) a tab protruding from the choke body a distance sufficient to identify the opening when the choke body and furnace inducer blower are installed in the furnace.

A combustion system includes a combustion chamber, a plurality of fuel introduction locations in the combustion chamber where fuel and air are provided to the combustion chamber for combustion, a fluid flow control device associated with each fuel introduction location, each fluid flow control device being controllable to vary an amount of the air supplied to each fuel introduction location, a plurality of sensing devices configured to monitor a plurality of operational parameters of the combustion system, and a control unit configured to control each fluid flow control device to control the amount of air supplied at each fuel introduction location independent of the amount of air supplied at the other fuel introduction locations, and to control the amount of air provided to all other air introduction locations, in dependence upon at least one of the plurality of operational parameters to minimize excess air provided to the combustion chamber.

A perforated flame holder and burner including a perforated flame holder provides reduced oxides of nitrogen (NOx) during operation. The perforated flame holder includes a pattern of elongated apertures extending between a proximal and a distal surface of the flame holder relative to a fuel nozzle. The perforated flame holder can provide a significantly reduced flame height while maintaining heat output from the burner.