| 摘要 |
PURPOSE:To lower the temperature of a main burner body and to improve the thermal efficiency and reliability thereof by forming the diameter of the downstream side of the main burner body larger than that of the upstream side thereof, and interposing a heat insulating member having an inner diameter which is the same as the inner diameter of the upstream side, in the inner part of the large-diameter portion. CONSTITUTION:A main burner body 11 has a downstream side 12 having a diameter which is larger than that of an upstream side. A cylindrical thermal insulating member 22 is inserted into a large-diameter portion 19, and the inner diameter of the member 22 is mad equal to that of an upstream side 13. Since air flowing into the main burner body 11 forms an upward swirl stream, flame holding begins at a turbulence forming body 18 or a fuel inlet port 17, and the flame becomes a flame along the inner wall of the main burner body 11 directed to an air inlet port 15. Consequently, the concentration of the combustion gas becomes high from the downstream of the fuel inlet port 17. However, since the heat insulating member 22 is provided at a part where the combustion gas concentration is relatively high, it is possible to lower the temperature of the main burner body 11. |
