| 摘要 |
PROBLEM TO BE SOLVED: To provide a seal mechanism capable of preventing a contact of the explosive gas or the ignitable gas with the atmospheric air even if a seal leak is generated in a seal part. SOLUTION: A seal mechanism 1 is provided with a shaft seal part formed of two O-rings 5a and 5b arranged along a reciprocating shaft 4 to be inserted into a wall 3 of a hydrogen treatment chamber 2, and a lead-in piping 9a from an argon gas source 11 is connected to one end of a space 6 of the shaft seal part formed between the O-ring 5a and the O-ring 5b, and a discharge piping 9b is connected to the other end thereof. A flow-meter 12 is provided on the way of the lead-in piping 9a, and a minute flow rate of the argon gas is made to flow under the pressure higher than the pressure of the hydrogen gas inside of the hydrogen treatment chamber 2 and the pressure of the atmospheric air. Even if a seal leak is generated, mixture of the hydrogen gas with the atmospheric air is prevented, and the seal leak is momentarily detected by the flow- meter 12. |
