Patent ID: 8851883

Claim:
A combustion method in a furnace having first and second opposed sides, each side being equipped with regenerators, a plurality of oxy-fired burners each one of which is upstream of the regenerators, and a plurality of air-fired burners each one of which is disposed downstream of the oxy-fired burners, said method comprising first and second cycles, wherein: the first cycle comprises the steps of: recovering heat from combustion flue gases by the regenerators on the first side; heating air using the heat recovered by the regenerators on the first side and combusting that heated air with fuel with the air-fired burners on the first side; simultaneous with said step of heating air using the heat recovered by the regenerators on the first side and combusting that heated air with fuel with the air-fired burners on the first side, combusting fuel and oxygen-rich oxidant with the oxy-fired burners on each of the first and second sides, the fuel and/or the oxygen-rich oxidant combusted with the oxy-fired burners being heated through heat exchangers with the heated air, the heat exchangers separate from the regenerators on the first side; and the second cycle comprises the steps of: recovering heat from combustion flue gases by the regenerators on the second side; heating air using the heat recovered by the regenerators on the second side and combusting that heated air with fuel with the air-fired burners on the second side; simultaneous with said step of heating air using the heat recovered by the regenerators on the second side and combusting that heated air with fuel with the air-fired burners on the second side, combusting fuel and oxygen-rich oxidant with the oxy-fired burners on each of the first and second sides, the fuel and/or the oxygen-rich oxidant combusted with the oxy-fired burners being heated through heat exchange with the heated air the heat exchangers separate from the regenerators on the second side.