| 摘要 |
PROBLEM TO BE SOLVED: To form a ventilation vent pipe provided between the shelter outside and the shelter inside, in a safe structure capable of avoiding danger to insertion of a dangerous material from an external part.SOLUTION: A vent pipe C of the present invention is constituted of a first vent pipe 1 and a second vent pipe 2, and the first vent pipe 1 is constituted of one or a plurality of upper vent holes 3, one or a plurality of lower vent holes 4 provided under its upper vent holes and a connection pipe 5 for connecting the upper vent holes and the lower vent holes, and the connection pipe 5 is installed in a substantially vertical shape along a shelter outer wall, and the second vent pipe 2 are connected at its one to the connection pipe 5 for connecting the upper vent holes 3 and the lower vent holes 4, and in the other, its vent hole is installed in a shelter. With such a constitution, when a solid-shaped or liquid-shaped dangerous material 8 is inserted from the upper vent hole 3, the dangerous material 8 is discharged from the lower vent hole 4. |
