| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem in a conventional freezing method of a fluid transport pipeline in which an intended passage stopping effect cannot be obtained by an ice block formed by freezing a part of a pipeline and icing a fluid in the pipeline inside a portion corresponding thereto of the pipe, since the ice block is pressed by a fluid pressure from a primary side and lost on a secondary side due to the absence of pressure.SOLUTION: In a freezing method of a fluid transport pipeline in which freezing means for freezing the fluid distributing in the fluid transport pipe are disposed in at least two positions of the fluid transport pipe, first and second ice blocks having an hourglass-shaped cross section are formed by gradually transmitting cold heat from a pipe wall side to a part inside the pipe corresponding to each of the freezing means, and a third ice block of which outside surface is shaped in a swollen curved surface is formed between the first and the second ice blocks. |
