| 摘要 |
PROBLEM TO BE SOLVED: To enable the execution of uniform heating by increasing the flame temperature in the vicinity of a burner even when a substance to be heated is positioned in the vicinity of a burner and further to reliably realize low NOx combustion by clarifying a range of a combustion air ratio in which an NOx generating amount can be suppressed even as the flame temperature in the vicinity of the burner is further increased than that of conventional arts. SOLUTION: In regenerative burners 3 and 4 to repeat a heat storage state and a combustion state at intervals of a given time, the burners are provided with primary fuel feed ports 3c and 4c, secondary fuel feed ports 3e and 4e, being different system, to feed fuel in a state to be divided into primary fuel and secondary fuel, the primary fuel feed port being opened in primary nozzles 3b and 4b, through which primary air passing thermal storage bodies 3a and 4a is injected, and the secondary fuel feed port being opened in secondary nozzles 3d and 4d situated approximately in parallel to the primary nozzle and secondary air feed ports 3f and 4f to feed secondary air in the secondary nozzles. A primary flame is formed as primary fuel and primary air are mixed in the primary nozzle on an air excess condition that an air ratio is 2 or higher. Secondary fuel and secondary air are fed through a system, different from that of primary air, not through a thermal storage body and form a secondary flame in a way that the secondary fuel and the secondary air are mixed together in the secondary nozzle on a fuel excess condition that an air ratio is 0.5 or lower. |
