PURPOSE: To obtain a combustion device, excellent in combustion properties when the amount of combustion is small and wide in the regulating range of the amount of combustion, by a method wherein an outer flame tube, whose upper diameter of the red-hot part thereof is made larger than the lower diameter of the same, is provided in the titled combustion device.
CONSTITUTION: A red-hot part 16 is formed in an outer flame tube 7 at a part above the vicinity of the throttle part 15 of the outer tube 9 while the red-hot part 16 is provided with through holes 17. The upper diameter of the red-hot part 16 is larger than the lower diameter of the same and a smaller space 19' is formed at the upper part of an outside air passageway 19 between the red-hot part 16 and the outer tube 18. Flame (f2) is formed under a condition that a wick 1 is kept low in a combustion chamber 8 when the exposure of the tip end of the wick 1 is small and the amount of combustion is small. In this case, unburnt gas (b) leaks into the outside air passageway 19 through the lower part of the red-hot part 16 and rises along with an air stream (a). Then, the unburnt gas flows into the combustion chamber 8 at the small space 19' again and is burnt perfectly by the flame (f2). Accordingly, the sudden deterioration in exhaust gas characteristics during the small-amount combustion may be improved and whereby the regulating range of the amount of combustion may be widened.
UNO KATSUHIKO
INOUE SHOJIRO
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