Issues with frequent start-up and shutdown of large air separation units
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We have an air separation unit with a capacity of over 50,000 units. Due to the fact that the plant was built not long ago and other issues, starting up and shutting down the unit is quite frequent. I would like to know if such frequent start-ups and shut-downs can cause any damage to the air separation equipment. Could there be leaks or other problems with the equipment inside the cryogenic tank as a result? Thank you
Frequent start-up and shutdown of the equipment cause containers, pipes, machines, etc. to alternate between normal temperatures and low temperatures repeatedly, experiencing multiple temperature stress changes. This can accelerate the aging of the equipment and lead to problems such as weld leaks or even pipe fractures.
What does “turbine” mean in a turbine expander? Could you please explain?
Turbine is the transliteration of the English word turbine
Agree with the opinion from the second floor. It’s not good to have the air separation system on and off intermittently. Especially in air separation units where the design margin for pipelines is not large, the likelihood of leaks increases after multiple startups and shutdowns.
Frequent starting and stopping also has a significant impact on large mechanical devices such as air compressors, boosters, and turbines; especially turbines, which encounter many problems during such operations
Frequent starting and stopping will reduce the service life of the equipment! !
It’s not good for the equipment, but it gives us many more opportunities to learn, haha~
Frequent starting and stopping definitely has an impact on the device’s performance
Frequent starting and stopping can damage rotating equipment such as compressors and expanders. Containers and pipes are prone to damage due to the impact of air currents, and the continuous alternation between normal and low temperatures causes significant thermal stress in the equipment, which can lead to cracks in welds and deformation of the equipment.
\"Turbine\" is a transliteration; in Chinese, it refers to a high-speed rotating impeller
Frequent starting and stopping can easily cause deformation of the pipes inside the cold box, especially aluminum alloy pipes; we have listed this issue first.
I’ve only heard that it has an impact on the equipment’s lifespan
We’ve just started operating it as well, and here are a few suggestions for you: 1. The temperature difference between the high-temperature and low-temperature exchangers should be controlled carefully – it’s best not to exceed 10 degrees Celsius, otherwise the exchanger is likely to leak. Our low-temperature exchanger has already leaked, and we’re preparing to replace it; this is currently affecting our production capacity – out of 40,000 units produced, only 30,000 can be obtained, which is really problematic. 2. Frequent starting and stopping also has a negative impact on the molecular sieve; it is essential to ensure the peak value of cold blowing. 3. Pay attention to turning on the cryopump; make sure it is in the correct position when exposed to cold, and do not rush to start it.
Reply to 3# Hongbo6656: \"Turbine\" is a transliteration; it refers to a worm gear. In cars, the presence of the letter \"T\" indicates turbocharging.
If the operation skills are good when starting and stopping frequently, it has little impact on the equipment inside the tower; however, frequent changes in compressor load have an inevitable effect. Recently, it hasn’t been started and stopped frequently. Before, there were small problems every time it was operated – issues such as the inlet guide vanes not aligning properly, fluctuations in the opening degree of the automatic valves on the tower, and especially discrepancies between the data from the compressor’s sensors and the previous operating data, which was really scary. All these problems were related to shutting down the equipment.
Similar to the opinion on floor 17. What is the “frequently” probability for the original poster?
Frequent start-up and shutdown have a significant impact on turbines, air compressors, boosters, molecular sieves, as well as the equipment and pipelines inside the cryogenic tank; it is best to avoid such frequent operations. But setting the idle air flow to 70 is already quite good; I’m not sure if there are more advanced settings. I would appreciate any advice from experienced users. Thank you