Burner employing flue-gas recirculation system with enlarged circulation duct

摘要

A method and apparatus are disclosed for use in furnaces such as those used in steam cracking. The apparatus includes a burner tube having a downstream end and an upstream end for receiving fuel and flue gas, air or mixtures thereof, with a burner tip being mounted on the downstream end of the burner tube adjacent a first opening in the furnace, so that combustion of the fuel takes place downstream of the burner tip. The burner includes at least one passageway having a first end at a second opening in the furnace and a second end adjacent the upstream end of the burner tube, the passageway having a cross-sectional area and shape sufficient to permit a total FGR (flue gas recycle) ratio of greater than 10%. In addition, the burner includes a means for drawing flue gas from the furnace through the passageway in response to an inspirating effect created by uncombusted fuel flowing through the burner tube.