| 摘要 |
PROBLEM TO BE SOLVED: To replace only a catalyst disposed near a raw material gas inlet easily and to control the generation of hot spots in a catalytic gas phase oxidation method by making a reaction raw material gas flow down from the upper part of a reaction tube and also the catalyst flow down from above downward in a reactor. SOLUTION: A raw material gas in which a reaction raw material and air are mixed is supplied from a raw material gas introduction inlet 2 into a reactor and discharged from a produced gas discharge opening 5 after being made to flow down in a reaction tube 4 to be oxidized. A heating medium after the recovery of the heat of reaction is extracted from a heating medium discharge opening 11 disposed below the reactor and, after being pushed up to a heating medium discharge pot 12 arranged above an upper part tube plate 6a, discharged from a nozzle 13 outside the system. Moreover, a cooling medium in the same amount as that of the heating medium is supplied from a cooling medium introduction tube 21 to secure a full heating medium state in the reactor. The cooling medium and the recovered heating medium, after being pumped up while being mixed by a pump 23, are supplied from a heating medium introduction tube 24 into the reactor. |
