A combustion system includes a fuel and oxidant source that outputs fuel and oxidant, a first perforated flame holder, and a second perforated flame holder separated from the first perforated flame holder by a gap. The first and second perforated flame holders sustain a combustion reaction of the fuel and oxidant within the first and second perforated flame holders.

No new matter has been added. The invention relates to a device for heating a medium, comprising a burner unit and a flame tube, wherein the burner unit generates flue gas, wherein the flame tube has a flue gas inlet, a longitudinal axis, a casing extending along the longitudinal axis, and an end face opposite the flue gas inlet, wherein the flue gas passes from the burner unit into the flame tube via the flue gas inlet, wherein a plurality of recesses are located in the casing, and wherein the recesses have different dimensions and/or are distributed asymmetrically on the casing. The longitudinal axis is in a central plane, wherein a first side and a second side of the casing are formed by the central plane, and wherein recesses on the first side have smaller dimensions than recesses on the second side.

A cooking burner includes a spreader defining a first side wall defining an outer profile having first and second extension sections opposed about a first axis. The spreader further defines first and second arced sections, each extending outwardly along a second axis perpendicular to the first axis from and between parallel straight segments of the first and second extension sections, respectively. The spreader further defines a second side wall disposed inwardly of and concentric with the first and second arced sections and a plurality of fuel outlets extending through both the first side wall and the second side wall. A circular inner cap is assembled with an upper portion of the circular inner profile, an annular outer cap is assembled with respective upper portions of the first and second arced sections, and first and second extension caps assembled with respective upper portions of the first and second extension sections.

Horizontal immersion tube boilers include a plurality of burner nozzles positioned in substantial alignment with a respective plurality of boiler tubes. Fuel-air mixture directed through the burner nozzles are ignited by a pilot flame system positioned proximate to the burner nozzles within a combustion chamber. The burner nozzles and pilot flame system receive air from a secondary air manifold having inlets that provide secondary air into the combustion chamber. The flames extending from the burner nozzles are directed into the respective boiler tubes, which exchange heat from the flame into water within a boiler shell. The secondary air inlets direct air around the burner nozzles and toward the boiler tubes, creating an air blanket around each burner nozzle for reducing turbulence and guide the flames into their respective boiler tubes. An improved flame arrestor within the nozzle prevents flame back-flow when modulating to lower firing rates.

A combustion system includes a fuel and oxidant source that outputs fuel and oxidant, a first perforated flame holder, and a second perforated flame holder separated from the first perforated flame holder by a gap. The first and second perforated flame holders sustain a combustion reaction of the fuel and oxidant within the first and second perforated flame holders.

A combustion system supports a swirl-stabilized preheating flame with a preheating fuel and an oxidant. The combustion system preheats a perforated flame holder with the preheating flame. After the perforated flame holder has been preheated to the threshold temperature, the combustion system outputs a primary fuel. The perforated flame holder receives a mixture of the primary fuel and the oxidant supports a combustion reaction of the primary fuel and the oxidant.

A cooking burner includes a spreader defining a first side wall defining an outer profile having first and second extension sections opposed about a first axis. The spreader further defines first and second arced sections, each extending outwardly along a second axis perpendicular to the first axis from and between parallel straight segments of the first and second extension sections, respectively. The spreader further defines a second side wall disposed inwardly of and concentric with the first and second arced sections and a plurality of fuel outlets extending through both the first side wall and the second side wall. A circular inner cap is assembled with an upper portion of the circular inner profile, an annular outer cap is assembled with respective upper portions of the first and second arced sections, and first and second extension caps assembled with respective upper portions of the first and second extension sections.

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.

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).