After the molecular sieve is pressurized, the gas flow rate into the tower increases suddenly. What is the reason? Sometimes it can increase to 1500 NM3/h
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As the title says! After the molecular sieve is pressurized, the gas flow rate into the tower increases suddenly. What is the reason? Sometimes it can increase by 1500 NM3/H. Under normal conditions, the flow rate into the tower is 25,000 NM3/h; after pressurization, it rises to 27,000 NM3/h. This air separation unit has been in operation for eight years without any replacement of the molecular sieve adsorbents.
This post was last edited by CHANGBAISHI on 2019-7-25 at 16:18. Every eight years, it is necessary to check whether the molecular sieve has experienced pulverization. Generally, molecular sieves have a shelf life of five years. Learn from past experiences – pull it out right away. If it can’t be replaced, it needs to be screened; once powder gets into the tower, that’s a real hassle. I’m not sure if the carbon dioxide level is within the acceptable range; if it is too high, replace it promptly. Is the pressurization time of the pressure equalizing valve sufficient? Such problems occur if the equalization period does not achieve the same pressure. Check the opening degree during the set time period – is the pressure after voltage equalization different? Looking at the trend chart, are the air intake volumes of the two purifiers different? Different pressures? ? If that’s the case, it’s likely that one of the switching valves for the purified gas is leaking internally.
It shouldn’t be an internal leak; usually, after pressurization, the amount of gas entering the tower remains basically the same. Moreover, our molecular sieve is equipped with pressure difference protection; if there is an internal leak, the molecular sieve will not operate automatically. There are two molecular sieves that operate in alternation: one is in use while the other is being regenerated. Each time it is pressurized, the amount of gas flowing into the tower increases slightly; however, as operation time progresses, this amount of gas gradually decreases.
Generally, changes in the gas flow rate into the tower are related to the pressure difference across the molecular sieve. I’m not sure whether the load on the air compressor remains the same after the molecular sieve is replaced.
After pressure equalization, operating in parallel leads to an increase in the amount of air entering the tower; subsequently, depending on the self-regulation mechanism of the air compressor’s guide vanes (either constant pressure or constant flow), the outlet flow rate gradually returns to its previous value~~
Check the conditions of the air compressor guide vanes, backflow, and venting; nothing can be discerned from this diagram
Mainly, the automatic control valve of the air compressor is not very sensitive; during the pressure equalization process, the system pressure drops, so the inlet guide vanes of the air compressor are opened wider to compensate for this. After voltage equalization is completed, the inlet guide vanes are slowly closed, resulting in a pattern that first increases and then decreases.
When switching molecular sieves, the pressure and flow rate at the air compressor outlet are stabilized, with hardly any significant fluctuations occurring