DECOMPRESSION BOILER TYPE CARBURETOR

PURPOSE:To prevent the degradation of heat transfer performance by disposing a steam lead-in tube and a condensed water return tube for connecting the lower part of a condensation chamber to the lower part of a can body, between a decompression boiler part and a condensation chamber part, and protruding plural heat transfer tubes from other heat transfer tubes in the condensation chamber. CONSTITUTION:A condensation chamber part 20 separate from a decompression boiler part 10 is connected to a steam chamber in an upper space inside the boiler part 10 by a steam lead-in tube 21, and the lower part of the noncondensable gas removing part 22 of the condensation chamber part 20 is connected to the lower part of the boiler part 10 by a condensed water return tube 23 so as to place the condensation chamber part 20 in the same decompressed atmosphere as the decompression boiler part 10. Inside the chamber 20, there is provided a heat transfer tube bundle 30 with LNG flowing inside, and the part, protruding from the heat transfer tube bundle 30, of a noncondensable gas removing heat transfer tube part 31 is made into a separate chamber to form the noncondensable gas removing part 22. The generated steam is led into the condensation chamber 20 from the steam lead-in tube 21, heat-exchanged with a low-temperature fluid, and returned into the boiler chamber 10 through the condensed water return tube 23. The steam containing the noncondensable gas is brought into contact with the heat transfer tube bundle 30, but the noncondensable gas can be collected into the U-shape tube part of the noncondensable gas removing heat transfer tube part 31 longer than the heat transfer tube bundle 30.