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 burner comprises: at least one mixing tube extending inside a fuel plenum and having an interior configured to be supplied with an air; and a plurality of fuel injection holes for injecting a fuel supplied to the fuel plenum into the interior of the at least one mixing tube. When the at least one mixing tube is viewed in an axial direction of the mixing tube, a central axis of each of the plurality of fuel injection holes is oblique in a same direction with respect to a circumferential direction of the mixing tube, to a radial direction of the mixing tube.

A burner comprises: at least one mixing tube extending inside a fuel plenum and having an interior configured to be supplied with an air; and a plurality of fuel injection holes for injecting a fuel supplied to the fuel plenum into the interior of the at least one mixing tube. When the at least one mixing tube is viewed in an axial direction of the mixing tube, a central axis of each of the plurality of fuel injection holes is oblique in a same direction with respect to a circumferential direction of the mixing tube, to a radial direction of the mixing tube.

Embodiments disclosed herein are directed to methods of upgrading a conventional combustion system into an upgraded combustion system that includes a perforated flame holder. For example, the perforated flame holder may improve operational efficiency of the combustion system and/or reduce pollutants such as NO.sub.x output by the upgraded combustion system.

The inventive concept relates to a swirler. According to an aspect of the inventive concept, there is provided a swirler including a casing, a pilot body disposed in the casing, and a plurality of vanes arranged along a circumference of the pilot body, wherein at least a part of the vane protrudes further to a downstream than an end portion of the pilot body.

The inventive concept relates to a swirler. According to an aspect of the inventive concept, there is provided a swirler including a casing, a pilot body disposed in the casing, and a plurality of vanes arranged along a circumference of the pilot body, wherein at least a part of the vane protrudes further to a downstream than an end portion of the pilot body.

A gas turbine engine and a combustor are described herein. The combustor includes a fuel vaporizer coupled to a combustor wall, which extends into a combustion chamber. A fuel injector having a nozzle extends within a portion of the fuel vaporizer. A dome swirler is coupled to an upstream dome portion of the combustor wall. The swirler surrounds a heat shield, which may have a concaved body. The outlet end of the fuel vaporizer is disposed over the heat shield, which may be over the central zone of the heat shield, to face the heat shield. The fuel vaporizer may be coupled to the combustor wall and disposed outside the swirler. Fuel and air mixture exits the vaporizer and impinges against the heat shield and is then combined with the swirler air to become part of the primary zone recirculation.

A fluid mixing device that includes a housing having a fuel inlet and at least one primary orifice positioned at the inlet, wherein the at least one orifice configured to disperse a stream of fuel into a plurality of fuel droplets. The plurality of fuel droplets contact a fuel impingement surface to break up the plurality of fuel droplets into a plurality of smaller secondary droplets and create a thin film of secondary droplets on the impingement surface. At least one pressurized air channel delivers an airflow into contact with the secondary droplets. The secondary droplets pass through a plurality of secondary outlet orifices to exit the housing. A size of the plurality of secondary droplets is reduced when passing out of the plurality of secondary orifices.

A fluid mixing device that includes a housing having a fuel inlet and at least one primary orifice positioned at the inlet, wherein the at least one orifice configured to disperse a stream of fuel into a plurality of fuel droplets. The plurality of fuel droplets contact a fuel impingement surface to break up the plurality of fuel droplets into a plurality of smaller secondary droplets and create a thin film of secondary droplets on the impingement surface. At least one pressurized air channel delivers an airflow into contact with the secondary droplets. The secondary droplets pass through a plurality of secondary outlet orifices to exit the housing. A size of the plurality of secondary droplets is reduced when passing out of the plurality of secondary orifices.

A burner capable of burning crude or other heavy oil. A combustion chamber is surrounded by a wall of thermal insulation. An air-fuel injector pipe extends through the wall and opens into the combustion chamber. An oil supply pipe extends along the interior of the air fuel injector pipe to an inner open end that is proximate the inner end of the air-fuel injector pipe. A venturi insert is fixed within the air-fuel injector pipe and has an orifice positioned outward of the open inner end of the oil supply pipe. A combustion air supply including a blower and a recuperator transfers heat from outgoing combusted exhaust gases to incoming combustion-supporting air being blown through the recuperator and the air fuel injector pipe into the combustion chamber.