A vehicle heater includes a burner area includes a circumferential wall providing a combustion chamber, a flame tube with a first end forming or adjacent to a part of the combustion chamber circumferential wall and a second flame tube end. A heat exchanger housing has a circumferential wall enclosing the flame tube. A waste gas backflow space is formed, between an outer side of the flame tube and an inner side of the heat exchanger housing circumferential wall, with an inlet area at the second flame tube end and with an outlet area in the area of the first flame tube end. An inner dimension of the circumferential wall increases in the direction from an inlet area of the waste gas backflow space to an outlet area. An outer dimension of the flame tube increases in the direction from the second flame tube end to the first flame tube end.

A refractory apparatus may include a refractory bock comprising a heat shield. The refractory block can include a group of flue gas ports that acts as a gateway for flue gas produced due to combustion downstream of a burner. A suction created in the burner drives the flue gas into the burner through the flue gas ports. A group of staged risers can be housed within the refractory block. The staged risers are protected in staged fuel riser housings in the refractory block. A discharge cone is located in the refractory block for flame stabilization in the burner.

A flame stabilization apparatus with fuel injection upstream of a torpedo, includes a flame stabilization plate that incorporates spokes that stabilize a flame over a range of operations of a burner. The spokes surrounds a fuel plenum with respect to the burner. A first group of fuel ports can be located in a fuel tube upstream of the torpedo and a second group of fuel ports can be located in the flame stabilization plate. A discharge cone includes a discharge zone for the burner, wherein the flame with respect to the flue gas is stabilized at an end of the burner in the discharge zone.

A method and device for reducing emissions of nitrogen oxides and for increasing heat transfer in a fired process heater is disclosed herein. The invention relates generally to the combustion of fuel using some proportion of air as the oxidant which leads to the production of oxides of nitrogen, and more particularly to a method and device that reduces the production of nitrogen oxides from combustion, promotes the appropriate distribution of temperature to reduce fouling of the process tubes in a fired heater, and increases the efficiency of heat transfer to the same process tubes.

The invention relates to a device (2) and a method for supplying combustion air and for recirculating exhaust gas for a burner (1) comprising a combustion chamber (10) and to a burner (1) comprising a device (2) for supplying combustion air and for recirculating exhaust gas. Multiple drive nozzles (21) distributed about a central axis (A) are used to supply combustion air to a mixing chamber (22) arranged downstream of the drive nozzles (21) by suctioning exhaust gases out of the combustion chamber (10); the combustion air exiting the drive nozzles (21) is mixed with exhaust gases in the mixing chamber (22) in order to form a combustion air/exhaust gas mixture, said exhaust gases flowing out of the combustion chamber (10) and being backflushed by means of the drive nozzles (21); and the combustion air/exhaust gas mixture is supplied to a reaction zone downstream of the mixing chamber (22).

Embodiments of the present invention include high-temperature staged recirculating burners and radiant tube burner assemblies that provide high efficiency, low NOx and CO emissions, and uniform temperature characteristics. One such staged recirculating burner includes a combustion tube having inside and outside helical fins forming opposing spiral pathways for combustion gases and products of combustion, a combustion nozzle coupled to the combustion tube, a gas tube running axially into the combustion tube, and a staging gas nozzle coupled to the gas tube, where the staging gas nozzle includes radial exit holes into the combustion tube and an axial gas staging tube extending into the combustion nozzle to stage combustion.

Embodiments of the present invention include high-temperature staged recirculating burners and radiant tube burner assemblies that provide high efficiency, low NOx and CO emissions, and uniform temperature characteristics. One such staged recirculating burner includes a combustion tube having inside and outside helical fins forming opposing spiral pathways for combustion gases and products of combustion, a combustion nozzle coupled to the combustion tube, a gas tube running axially into the combustion tube, and a staging gas nozzle coupled to the gas tube, where the staging gas nozzle includes radial exit holes into the combustion tube and an axial gas staging tube extending into the combustion nozzle to stage combustion.

Regenerative burner for non-symmetrical combustion and a method of firing the burner. The burner includes a burner housing enclosing a burner plenum; a fuel conduit extending longitudinally within the housing and positioned coaxial with a line spaced from a central axis of the burner, with the fuel conduit defining a fuel exit opening; and a baffle positioned at least partially around the fuel conduit and defining an air conduit extending into the housing and defining an air opening on an opposite side of the burner central axis from the fuel exit opening. The baffle also defines a cavity adjacent the fuel exit opening and in communication with the fuel conduit through the fuel exit opening. The sidewall of the cavity converges from a central axis of the fuel conduit to provide further jet penetration into the furnace and achieve greater levels of products of combustion entrainment prior to combustion.

A method for reducing nitrogen oxide NOx emissions during combustion of a gaseous fuel in a burner intended for a naked-flame or controlled-atmosphere reheating furnace, for reheating steel products or for continuous coating and/or annealing of metal strips, wherein a first dilution is carried out by mixing combustion air with combustion products upstream from or in the body of the burner, and a second dilution is carried out directly at the level at which the gaseous fuel reacts with the combustion air, mixing the fuel with a recirculated portion of the flame or products of partial combustion, the double dilution enabling the physical and chemical properties of the gas to be modified in order for the burner to operate with low oxygen rates and obtain a flame that produces a very low level of NOx production regardless of the temperature of the enclosure in which the combustion takes place.

An evaporator burner arrangement (100) for a mobile heater operated with liquid fuel having: a mixture preparation region (2) for generating a fuel-air-mixture, a fuel evaporation surface (8) arranged in the mixture preparation region (2) for evaporating the liquid fuel, a combustion air supply (B) for supplying combustion air to the mixture preparation region (2), a fuel supply (1) for supplying liquid fuel to the fuel evaporation surface (8), a conversion region (3) being arranged fluidically downstream of the mixture preparation region (2) for converting the fuel-air mixture in order to release heat, and a heat conductor body (7) extending spaced from a sidewall (25) of the mixture preparation region (2) through the mixture preparation region (2) to the conversion region (3) for feeding-back heat from the conversion region (3) to the mixture preparation region (2) by thermal conductance