| 摘要 |
PROBLEM TO BE SOLVED: To improve combustion stability by reliably preventing a lift of a flame from a burner and enable a substance to be heated to be uniformly heated at a given temperature, and enable a change of flame temperature distribution. SOLUTION: A primary fuel nozzle 7 is mounted such that combustion air can be injected in a nozzle 6 for combustion air from the periphery of a flow of combustion air, and a plurality of secondary fuel nozzles are provided. Secondary fuel nozzles 8A and 8B provided with a flame holding mechanism containing flow passages 5c and 5d capable of feeding flame holding air from the periphery of injecting secondary fuel are provided at injection outlets at the tips of respective piping. Constitution is effected such that direct blowing in a furnace approximately in parallel to the combustion air nozzle 6 is practicable from a place different from combustion air, and secondary fuel flow rate regulating valves 14a and 14b are respectively provided and flame temperature distribution can be changed. |
