Refrigerated container seal gas
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Generally, the sealing gas in a cold box consists only of purified nitrogen; what should be done if there is no purified nitrogen available in the event of an emergency shutdown? Can we add some more instrument air?
Here, we are connecting the nitrogen filling pipelines of another air separation cryogenic tank to serve as a backup for each other
The gas used as a shielding gas must be dry; if air is used, the large amount of water present in air will evaporate from the cold perlite, causing the perlite to clump together and damaging the equipment. Therefore, the sealing gas in cold chambers is always dry nitrogen! As for you having parked the vehicle, there’s no need for nitrogen protection anymore! If it is for long-term parking, then protection using molecular sieves can be considered; the other options are optional. Of course, choosing the best option for that situation is ideal! ! !
It’s possible. The instrument air is also dry air; dirty nitrogen is used in order to reduce waste – it’s the same principle
It’s not always possible to ensure a good dew point for instrument air!
We use dry product nitrogen in small quantities; it is relatively safe. Pure nitrogen can also be used to check for any minor leaks of oxygen-containing gases inside the cryogenic box.
Well, using nitrogen is also a great method! ! !
May I ask, for how long can the 3rd floor operate without interruption in dry contaminated nitrogen gas?
Instrument air is acceptable; while the vehicle is running, the instrument air comes from purified air. But where does the instrument air come from if the vehicle is parked for a long time?
9# zyp_tz can be switched to nitrogen from the liquid nitrogen backup system.
For operations such as maintaining cold temperature during the shutdown of the cold box, the existing contaminated nitrogen gas can be used; the air supply valve in the middle and lower sections should be slightly opened, while the air supply valve at the top can be opened wider to prevent moist air from entering from above. It is not recommended to use nitrogen or contaminated nitrogen from other devices as the gas for the gas seal; an excessive amount of heat entering the cryogenic tank causes a large amount of vaporization of the liquids inside it, especially oxygen-rich liquids. During shutdown, when there is no flow, this extensive vaporization can lead to the accumulation of hydrocarbons, posing a risk of local combustion and explosion in the cryogenic tank.