Abstract: A combustion system includes a perforated flame holder configured to hold a main combustion reaction substantially between input and output faces thereof. A main fuel nozzle is positioned to emit a main fuel stream toward the input face. An igniter assembly is configured to ignite a preheat flame supported by the main fuel stream between the main fuel nozzle and the perforated flame holder, and to selectably control a degree of ignition of the fuel stream by the preheat flame. During a start-up of the combustion system, the perforated flame holder is preheated by the preheat flame. When the perforated flame holder reaches a start-up temperature, the preheat flame is shifted from fully igniting to partially igniting the fuel stream, allowing fuel and oxidant to reach the perforated flame holder. A flame is ignited in the perforated flame holder while the preheat flame burns. The preheat flame is then released.

Abstract: A process oven includes a housing structure with a conveyor system configured to carry product through a housing structure from a first opening to a second opening. A perforated flame holder is positioned within the housing structure and configured to apply, to the product, thermal energy released by a combustion reaction held by the perforated flame holder.

Abstract: A water heater includes a water tank having an inlet and an outlet, and a flue extending through the tank. A nozzle is positioned near a first end of the flue, arranged so as to emit a fuel stream into the flue, and a flame holder is located within the flue in a position to receive the fuel stream and to hold a flame entirely within the flue.

Abstract: 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 perforated 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.

Abstract: 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.

Abstract: A combustion system includes a perforated reaction holder having perforations defined to compensate for a non-uniform velocity of fuel and/or oxidant received across an input face of the perforated reaction holder.

Abstract: A combustion system includes a fuel and oxidant source, a perforated flame holder, and a support structure that supports the perforated flame holder at a selected distance from the fuel and oxidant source. The fuel and oxidant source outputs fuel and oxidant onto the perforated flame holder. The perforated flame holder receives the fuel and oxidant and sustains a combustion reaction of the fuel and oxidant within the perforated flame holder.

Abstract: A water heater includes a water tank having an inlet and an outlet, and a flue extending through the tank. A nozzle is positioned near a first end of the flue, arranged so as to emit a fuel stream into the flue, and a flame holder is located within the flue in a position to receive the fuel stream and to hold a flame entirely within the flue.

Abstract: A burner system that employs a perforated flame holder and is configured to combust a powdered solid fuel includes a structure configured to protect the perforated flame holder from erosion caused by particles of the solid fuel.

Abstract: A combustion system includes a perforated flame holder, an oxidant source, and an adjustable fuel nozzle. The oxidant source outputs oxidant. The adjustable fuel nozzle outputs fuel onto the perforated flame holder. The perforated flame holder supports a combustion reaction of the fuel and oxidant within the perforated flame holder. The position of the adjustable nozzle relative to the perforated flame holder can be adjusted to achieve selected characteristics of the combustion reaction within the perforated flame holder.

Abstract: A combustion system such as a furnace or boiler includes a perforated reaction holder configured to hold a combustion reaction that produces very low oxides of nitrogen (NOx).

Abstract: 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.

Abstract: A burner system includes a perforated flame holder configured to hold a combustion reaction and a plurality of fuel nozzles aligned to deliver respective fuel streams to the perforated flame holder.

Abstract: A rotary kiln includes a stationary fuel nozzle and a perforated flame holder positioned within an inclined rotating shell. The flame holder includes a plurality of perforations that collectively confine a combustion reaction of the burner to the flame holder to shift most heat transfer from the combustion reaction from radiation heat transfer to convective heat transfer.

Abstract: 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.

Abstract: A combustion system such as a furnace or boiler includes a perforated reaction holder configured to hold a combustion reaction that produces very low oxides of nitrogen (NOx).

Abstract: A water heater includes a water tank having an inlet and an outlet, and a flue extending through the tank. A nozzle is positioned near a first end of the flue, arranged so as to emit a fuel stream into the flue, and a flame holder is located within the flue in a position to receive the fuel stream and to hold a flame entirely within the flue. A controller variably controls a flow of fuel to the nozzle according to a temperature of water in the tank.

Abstract: A flame holder assembly includes a flame holder element and a flame shield element. The flame holder element has a first plurality of apertures extending through the flame holder element. The flame shield element has a second plurality of apertures extending through the flame shield element. Each of the second plurality of apertures has a lateral dimension that is no greater than a flame quenching distance. The flame shield element is positioned facing the flame holder element, and the flame holder assembly is configured such that fuel is supplied to the flame holder element via the second plurality of apertures of the flame shield element.

Abstract: A cracking furnace includes a combustion volume defined in part by a burner wall having a refractory lining. A plurality of perforated flame holders is arranged in an array that is spaced away from the wall, with fuel input faces facing the wall. Each of a plurality of fuel nozzles is positioned and configured to emit a fuel stream toward the input face of a respective one of the plurality of perforated flame holders. Combustion reactions, supported by the fuel streams emitted by the fuel nozzles, and held by the flame holders, release heat, which is emitted by the flame holders as thermal (blackbody) radiation, a portion of which impinges upon, and heats the inner face of the refractory lining. Thermal radiation from the flame holders and the wall impinges upon a load positioned in the approximate center of the combustion volume, between burner walls.

Abstract: A burner includes a perforated flame holder configured to be disposed at a plurality of locations relative to a fuel and air source.