A combustor includes a distal end portion which forms a nozzle extending along an axis and opening at a distal end; an intermediate portion having a mixing surface which defines a mixing space in which air and fuel are mixed, by gradually expanding to an outer side in a radial direction of the axis from the nozzle to a rear, behind the distal end portion; a proximal end portion which forms a fuel space to which fuel is supplied from outside, behind the intermediate portion; and a plurality of air introduction pipes which penetrate the proximal end portion in a direction of the axis, have a distal end communicating with the mixing space, are arranged in a circumferential direction of the axis to surround the axis, and have a fuel supply hole formed on an inner side in a radial direction of the axis to communicate with the fuel space.

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 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.

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.

A horizontally-fired burner system includes, in a combustion volume, a distal flame holder, the distal flame holder including a plurality of columns each formed from a respective plurality of refractory tiles, and a fuel and combustion air source configured to output a flammable fuel and air mixture toward the distal flame holder. The distal flame holder is configured to hold a combustion reaction adjacent to each of the plurality of columns.

A horizontally-fired burner system includes, in a combustion volume, a distal flame holder, the distal flame holder including a plurality of columns each formed from a respective plurality of refractory tiles, and a fuel and combustion air source configured to output a flammable fuel and air mixture toward the distal flame holder. The distal flame holder is configured to hold a combustion reaction adjacent to each of the plurality of columns.

A duel-fuel fireplace apparatus is described. In one example, an apparatus includes an enclosure having a door disposed thereon and a wood burning compartment disposed within the enclosure. The wood burning compartment has an insulated housing configured to support temperatures associated with burning of wood within the wood burning compartment. A gas burning compartment is also disposed within the enclosure and has a gas burner disposed therein. A mechanism including a motor is configured to cause movement between a first mode in which the wood burning compartment is viewable through the door and a second mode in which the gas burning compartment is viewable through the door.

A duel-fuel fireplace apparatus is described. In one example, an apparatus includes an enclosure having a door disposed thereon and a wood burning compartment disposed within the enclosure. The wood burning compartment has an insulated housing configured to support temperatures associated with burning of wood within the wood burning compartment. A gas burning compartment is also disposed within the enclosure and has a gas burner disposed therein. A mechanism including a motor is configured to cause movement between a first mode in which the wood burning compartment is viewable through the door and a second mode in which the gas burning compartment is viewable through the door.

A combustion burner includes a plurality of splitters (5), (6), (7) configured to divide a fuel gas flow by a widened portion where a width of the widened portion increases as the widened portion extends in the direction of the fuel gas flow. The splitters include: slitted splitters (5), (6) configured to slits (SL) at a downstream end in the fuel gas flow; and non-slitted splitters (7) configured to adjacently to the slitted splitters (5), (6), each of the non-slitted splitters (7) configured to the widened portion at a downstream end in the fuel gas flow, and configured to a fixed width in a direction of the longitudinal axis.

A combustion burner includes a plurality of splitters (5), (6), (7) configured to divide a fuel gas flow by a widened portion where a width of the widened portion increases as the widened portion extends in the direction of the fuel gas flow. The splitters include: slitted splitters (5), (6) configured to slits (SL) at a downstream end in the fuel gas flow; and non-slitted splitters (7) configured to adjacently to the slitted splitters (5), (6), each of the non-slitted splitters (7) configured to the widened portion at a downstream end in the fuel gas flow, and configured to a fixed width in a direction of the longitudinal axis.