The premixing device includes a first and a second venturi having a pressure reducing portion for air, and a gas supply passage for supplying fuel gas to the venturis, and generates air-fuel mixture by mixing fuel gas with air flowing in the venturi by using a fan and supplies the air-fuel mixture to a burner. A first and a second nozzles for reducing pressure of fuel gas are disposed in the gas supply passage, and the first and the second nozzles are formed in the same nozzle shape as the pressure reducing portion of the first and the second venturis.

The disclosure relates to a gas-heated infrared radiation emitter comprising at least one radiating screen, which is for example made of ceramic and/or metal, in the form of at least one plate comprising a lower main surface and an upper main surface that are distant from each other, and a plurality of through-prisms, which are preferably hollow, extending from the lower main surface to the upper main surface, each prism being defined by a polygonal base and by an axis. The prisms may be juxtaposed with one another so that their polygonal bases form a tiling of at least one portion of the lower and upper main surfaces of said plate.

A gas burner system has a gas burner with a conduit through which an air-gas mixture is conducted; a variable-speed forced-air device that forces air through the conduit; a control valve that controls a supply of gas for mixture with the air to thereby form the air-gas mixture; and an electrode configured to ignite the air-gas mixture so as to produce a flame. The electrode is further configured to measure a flame ionization current associated with the flame. A controller is configured to actively control the variable-speed forced-air device based on the flame ionization current measured by the electrode so as to automatically avoid a flame harmonic mode of the gas burner. Corresponding methods are provided.

The premixing device includes a first and a second venturis having a pressure reducing portion for air, and a gas supply passage for supplying fuel gas to the venturis, and generates air-fuel mixture by mixing fuel gas with air flowing in the venturis by using a fan and supplies the air-fuel mixture to a burner. A first and a second nozzles for reducing pressure of fuel gas are disposed in the gas supply passage, and the first and the second nozzles are formed in the same nozzle shape as the pressure reducing portion of the first and the second venturis.

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).

Aspects and features of a burner for a cooking appliance include a first plate defining flame ports arranged in flow-sharing groups around a periphery of a combustion surface and a second plate coextensive with the first plate. Each plate is contoured so that the plates define an annular void within the burner. The annular void is fluidly coupled to the flame ports. In some aspects, each flow-sharing group includes clusters of flame ports, with each cluster including flame ports of two different diameters. The plates can each be made using the same tool such as a die, stamp, or mold, and the burner can be sized and installed in a cooking appliance so that it extends to cover a large portion of a wall of the cooking cavity of the appliance.

A burner for a fire heating appliance may include a plenum for holding a quantity of fuel and a burn surface. The burn surface may include an apex wherein the burn surface slopes away from the apex and a plurality of orifices for passing fuel from the plenum therethrough. Each orifice may be surrounded by a sidewall. An outdoor heating appliance may include a base portion, a top portion, and a burner. The burner may be arranged in the top portion and may be configured for releasing fuel to form a flame. The burner may include a top pan portion and a bottom pan portion. The top and bottom pan portions may be arranged to form a plenum for containing and releasing fuel. The top pan portion may include a plurality of orifices having a raised sidewall.

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).

A gas burner system has a gas burner with a conduit through which an air-gas mixture is conducted; a variable-speed forced-air device that forces air through the conduit; a control valve that controls a supply of gas for mixture with the air to thereby form the air-gas mixture; and an electrode configured to ignite the air-gas mixture so as to produce a flame. The electrode is further configured to measure a flame ionization current associated with the flame. A controller is configured to actively control the variable-speed forced-air device based on the flame ionization current measured by the electrode so as to automatically avoid a flame harmonic mode of the gas burner. Corresponding methods are provided.

In a fuel and oxidant combustion system, a flame holder support structure includes a heating element that receives electrical energy from an electrical power source. The heating element is raised to an auto-ignition temperature of a fuel and oxidant mixture directed, along an axis proximate the flame holder support structure, to a flame holder for combustion thereof.