| 摘要 |
PURPOSE:To prevent the production of tar, to bring only a required evaporating surface part to a high-temperature state and other part to a low-temperature condition, and to improve durability, by partially increasing the heat collecting area, at the outer peripheral wall, of an evaporating tube, of which the outer peripheral wall is heated by an exhaust gas. CONSTITUTION:By feeding a liquid fuel and the air for combustion in an evaporating chamber 14, the liquid fuel is evaporated at the lower side wall of an evaporating tube 2, the fuel, mixed with the air for combustion, produces a mixed gas to be burnt in a combustion tube 9. A high-temperature combustion exhaust gas generated by combustion is exhausted through an exhaust port 28 formed in a support tube 29 after passing through an exhaust space 10, and in which case, the exhaust gas contacts the outer peripheral wall of the evaporating tube 2 to heat the evaporating tube 2. Heat collecting fins 101 are located on the lower side wall of the outer periphery of the evaporating tube 2, and thereby more heat is imparted to the lower side wall from the exhaust gas to bring the tube to a high-temperature state. As a result, even if the evaporating latent heat is absorbed resulting from evaporating of the liquid fuel, the tube is prevented from being brought to a low-temperature state, a sufficient amount of the heat is supplied to the lower side wall of the evaporating tube 2, whereby it is unnecessary to bring the other part of the evaporating tube 2 to a high-temperature condition. |
