| 摘要 |
PROBLEM TO BE SOLVED: To maintain a freezing line arranged on an entire perimeter of an underground storage tank, which stores a low-temperature liquefaction gas such as LNG, at a desired position.SOLUTION: A side heater 4, which is buried in a foundation 2 around a periphery of an underground storage tank 1, comprises: an inner pipe 5 extending in vertical direction, in which a heater liquid is poured from an upper part and drained from a lower part; an outer pipe 6, which surrounds the inner pipe 5 and makes the heater liquid drained from the lower part of the inner pipe 5 flow through and drains the heater liquid from the upper part. At least a part of side heater 4A has an extended diameter part 20 that is formed by locally extending the diameter of the outer pipe 6.SELECTED DRAWING: Figure 1 |
