| 摘要 |
PURPOSE:To prevent a foundation around a cryounderground tank from freezing by making smaller a space between a heat fence and the outer wall of the tank as the depth becomes larger. CONSTITUTION:Rod-like heaters 2 constituting a heat fence are embedded slightly inclined to the vertical outer wall of a tank 1 so that a gap between the heat fence and the outer wall of tank 1 is made smaller as the depth becomes larger. Thus, the larger the depth is, the more heat reaches the outer wall of tank 1 from the heat fence, and the temperature gradient in the depth direction of the outer wall of tank 1 is lessened, so that the surface temperature of the outer wall of tank 1 can be maintained approximately at the freezing point irrespective of the depth and the freezing condition around the tank 1 can be prevented from expansion. |
