Main cooling liquid level gauge issue
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I recently encountered a problem: the positive pressure tube of the main cooling liquid level gauge in the unit was blocked. Attempting to clear it by using nitrogen from a cylinder didn’t work, and the backup positive pressure tube was also in poor condition, showing frequent fluctuations. By connecting a reverse blowing line, the issue could be resolved, but there is still uncertainty – if it fails to work again, it will cause problems. Are there any good solutions without stopping?
Is the pearlescent sand clogged? ~~Backblowing is only a temporary solution~~It’s recommended to carry out maintenance at an appropriate time~~
Originally, it was planned to remove the sand for inspection, but the maintenance schedule changed and there wasn’t enough time for that; so instead, the temperature was raised significantly. Once it reached room temperature, air was blown in using a reverse-blowing cylinder to clear the blockage, after which the equipment was started up immediately. After it began operating, the amount of coolant discharged increased, and this continued for some time. After about 20 days of operation, the blockage occurred again.
At room temperature, when the pressure inside the tower is not high, backwashing is possible; however, this does not mean that backwashing can be carried out during operation. Since it is a positive-pressure system, the effect of the liquid column must be taken into account. During normal operation, a tower pressure of around 5 bar needs to be considered, as well as the adhesion of perlite to the tube walls in an oxygen-rich environment. If problems arise, it’s better to carry out maintenance as soon as possible to avoid serious accidents. Has the base temperature of the cryogenic tank decreased?~~
Why are you so sure it’s caused by pearlescent sand clogging? There is no base temperature; it’s a single tall tower. The cold box has been checked and shows no problems. It has been blocked for not just a day or two, but almost two years now. The pressure at the top of the tower is increased by 2 kilograms due to the liquid column; 10 kilograms of air pressure is used, and I don’t dare to increase it any further – I’m afraid. I just took over this set of equipment, and I’m not familiar with the specific procedures involved in the installation and debugging process; therefore, I’m not sure what is causing the blockage right now
Blockages can be caused by mechanical impurities, which should be detected during the commissioning process. Another possibility is ice blockage; in such cases, increasing the temperature might help. However, as long as the molecular sieve is functioning properly, blockages will not occur during operation. The remaining possibility is sand blockage~~
High-purity nitrogen equipment? How much?