Purging of 100m3 liquid nitrogen storage tank
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Who has a purging plan for a 100m3 liquid nitrogen tank, or any relevant information or experience in this area? Could you please advise? Thank you! :)
Generally, the equipment leaves the factory with a slight positive nitrogen pressure seal, but it is best to measure the dew point to ensure it meets the requirements. Once this is confirmed, the tank can be filled directly with the medium to be stored. If the dew point does not meet the requirements, it is necessary to first adjust it to the specified level before proceeding with cooling the tank~~
Hello, what are the specific standards that the dew point and oxygen content need to meet in order to be considered acceptable?
National standards specify that the water content in liquid nitrogen should be below 3 ppm; generally, this is achieved by cooling it to a temperature at which the dew point is below -60 degrees Celsius (around 10 ppm). Regarding the oxygen content, it depends on the specifications of your liquid nitrogen – whether it is pure nitrogen or high-purity nitrogen. Nowadays, high-purity nitrogen is generally used, with an oxygen content of less than 3 ppm. As long as the dew point meets the requirements, liquid nitrogen can be used for vaporization replacement and tank cooling~~
For a tank with a working pressure of 0.8 MPa, what is the replacement pressure, and how many times is replacement generally required? We want to achieve less than 1 ppm. How long is the cold tank? What needs to be noted?
The displacement pressure is lower than the operating pressure; if the dew point meets the requirements, pre-cooling is carried out using liquid nitrogen vaporization~~Assuming a nitrogen content of 99.9%, approximately 1–2 tons of liquid nitrogen are required~~
If it is confirmed that there are no particles, slag, or other debris in the storage tank, a pressure of 0.1 MPa is sufficient; there is no need for a higher pressure. If you’re concerned about purity and dew point, 20 replacements are definitely sufficient. The amount of liquid used might be a bit more, around 5 tons I guess
Using so much will get the boss angry~~ Hehe