A method heats a furnace process chamber with the combustion of fuel gas. The method heats the process chamber in a preheat mode when the temperature of the process chamber is below the autoignition temperature of the fuel gas. The preheat mode forms preheated combustion air by directing the combustion air through a regenerative bed. A stream of the preheated combustion air is directed into the process chamber in a condition unmixed with fuel gas. The preheat mode also forms a fuel rich mixture of the fuel gas and unheated combustion air. The fuel rich mixture is directed into the process chamber adjacent to the stream of preheated combustion air.

The present invention relates to a combustion apparatus capable of reducing the emission amount of nitrogen oxide and enabling stable combustion in the entire area of a set load. The combustion apparatus includes: a premixing chamber for premixing air and a gas; a blower for supplying a mixed-gas of the air and the gas to a burner; a combustion chamber for burning the mixed-gas by ignition of the burner; a heat exchanger for exchanging heat with water by using combustion heat in the combustion chamber; and an exhaust gas discharge part for discharging the exhaust gas passing through the heat exchanger, wherein the premixing chamber is formed in a Venturi shape having a throat part of which the cross-section area is tapered between an inlet and an outlet through which the air passes, the throat part of the premixing chamber being connected to a gas supply part for supplying a gas for combustion, and to an exhaust gas recirculation tube to which some of the exhaust gas having passed through the heat exchanger is introduced in proportion to differential pressure according to the flow rate of the mixed-gas passing through the throat part.

The present invention relates to a combustion apparatus capable of reducing the emission amount of nitrogen oxide and enabling stable combustion in the entire area of a set load. The combustion apparatus includes: a premixing chamber for premixing air and a gas; a blower for supplying a mixed-gas of the air and the gas to a burner; a combustion chamber for burning the mixed-gas by ignition of the burner; a heat exchanger for exchanging heat with water by using combustion heat in the combustion chamber; and an exhaust gas discharge part for discharging the exhaust gas passing through the heat exchanger, wherein the premixing chamber is formed in a Venturi shape having a throat part of which the cross-section area is tapered between an inlet and an outlet through which the air passes, the throat part of the premixing chamber being connected to a gas supply part for supplying a gas for combustion, and to an exhaust gas recirculation tube to which some of the exhaust gas having passed through the heat exchanger is introduced in proportion to differential pressure according to the flow rate of the mixed-gas passing through the throat part.

A burner for heating a heating space with a reduction of NOx emissions is provided. The burner includes a mixing and combustion chamber, a mixing and igniting device disposed in the mixing and combustion chamber, and a fuel feed connected to the mixing and igniting device and configured for feeding fuel to the mixing and igniting device. Further, an air feed is provided, which is configured for feeding at least one partial air flow to the mixing and combustion chamber. A combustion chamber opening opens the mixing and combustion chamber towards a heating space to be heated. Furthermore, control means are configured for controlling a fuel flow via the fuel feed and for controlling at least one partial air flow via the air feed.

A burner for heating a heating space with a reduction of NOx emissions is provided. The burner includes a mixing and combustion chamber, a mixing and igniting device disposed in the mixing and combustion chamber, and a fuel feed connected to the mixing and igniting device and configured for feeding fuel to the mixing and igniting device. Further, an air feed is provided, which is configured for feeding at least one partial air flow to the mixing and combustion chamber. A combustion chamber opening opens the mixing and combustion chamber towards a heating space to be heated. Furthermore, control means are configured for controlling a fuel flow via the fuel feed and for controlling at least one partial air flow via the air feed.

An evaporator burner for a mobile heating device is provided having a combustion chamber, an evaporator accommodation, and an evaporator element for evaporation of liquid fuel. The evaporator element is accommodated in the evaporator accommodation at the side facing the combustion chamber. At the side of the evaporator accommodation facing away from the combustion chamber, the evaporator burner comprises at least one combustion air guide element which is arranged such that a combustion air flow path extending at least along a portion of a base wall of the evaporator accommodation is formed between the combustion air guide element and the base wall of the evaporator accommodation.

An evaporator burner for a mobile heating device is provided having a combustion chamber, an evaporator accommodation, and an evaporator element for evaporation of liquid fuel. The evaporator element is accommodated in the evaporator accommodation at the side facing the combustion chamber. At the side of the evaporator accommodation facing away from the combustion chamber, the evaporator burner comprises at least one combustion air guide element which is arranged such that a combustion air flow path extending at least along a portion of a base wall of the evaporator accommodation is formed between the combustion air guide element and the base wall of the evaporator accommodation.

A method heats a furnace process chamber with the combustion of fuel gas. The method heats the process chamber in a preheat mode when the temperature of the process chamber is below the autoignition temperature of the fuel gas. The preheat mode forms preheated combustion air by directing the combustion air through a regenerative bed. A stream of the preheated combustion air is directed into the process chamber in a condition unmixed with fuel gas. The preheat mode also forms a fuel rich mixture of the fuel gas and unheated combustion air. The fuel rich mixture is directed into the process chamber adjacent to the stream of preheated combustion air.

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.