| 摘要 |
PURPOSE:To cause unburnt gas leaked into an external air passage to be reflowed into a combustion chamber to make a complete combustion and to prevent a flowing-out of the unburnt gas under a low amount of combustion by a method wherein a diameter of an upper part of an external flame cylinder is made larger than a diameter of a lower part of the cylinder and at the same time an upper end of the external air passage formed between the external flame cylinder and an outer cylinder is closed. CONSTITUTION:Unburnt gas (arrow b) generated under a low volume combustion is leaked from a lower part of a red heated part 16 into an air passage 19 and ascends in the external air passage 19 along the red heated part 16. Since a diameter of the upper part of the red heated part 16 is made larger than a diameter of the lower part of the cylinder, the upper part of the external air passage 19 forms a small spacing 19' to cause a high passage resistance to be increased. Since the upper end of the external air passage 17 is completely closed by a top frame 20, unburnt gas within the external air passage 19 is caused to approach an outer wall of the red heated part 16 as it approaches the small spacing 19' and at the same time a part of it is reflowed into a combustion chamber 8 to make a complete combustion.
|
