PURPOSE: To carry out operation at a temperature lower than an allowable temperature of a nozzle member by a method wherein a disk-like spacing is provided with an air injection port opened toward a flame burning plane.
CONSTITUTION: A disk-like spacing 9 is formed between an oil fuel injection port 8 and a gas fuel injection port 6a. Flame with gas combustion under a low calorie combustion is generated at an outer circumference of a fuel nozzle 4, and then portions near the oil fuel injection port 8 and the disk-like spacing 9 are exposed to recirculation flow of high temperature. In this case, the disk- like spacing 9 is provided with the air injection port 15 and air is injected from the air injection port 15, resulting in that the surface temperature can be decreased below an allowable temperature of the material of the nozzle 4 under a cooling effect of the air. With such an arrangement, it is possible to perform the reliable operation at a temperature less than the allowable temperature of the material of the nozzle 4.
IIZUKA NOBUYUKI
GUNJI TSUTOMU
IWAI KAZUMI
KOIZUMI HIROMI
INOSE HIROSHI
KUMADA KAZUHIKO
TORITANI HAJIME
