| 摘要 |
<p>Large numbers of vent holes (90, l00) are respectively formed in inner and outer flame cylinders (82, 86) defining an annular combustion chamber (84) to supply air therto. A total opening area of the vent holes (l00) formed in the outer flame cylinder (86) is greater than that of the vent holes (90) formed in the inner flame cylinder (82). As a result, the heat capacity of the outer flame cylinder (86) is smaller than that of the inner flame cylinder (82). During combustion, the outer flame cylinder (86) is heated to red-hot. A plurality of projections (99) are formed on the outer wall surface of the inner flame cylinder (82) to allow complete combustion of a fuel vapor. </p> |
