Why is helium installed at the top of the condensation evaporator? Neon purge line?
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For 28,000 capacity air separation unit, the main cooler is two meters in length; oxygen and nitrogen separation is carried out
Hehe, the principle is quite simple. In fact, what gets blown away isn’t just neon and helium; there are also other trace gases. Since it is nitrogen that condenses in the main cooler, gases with a lower boiling point than nitrogen cannot condense. As a result, these gases accumulate at the top of the main cooler, reducing the heat exchange area and affecting its performance
Check the composition of air; in addition to oxygen and nitrogen, there are also gases such as helium, neon, argon, krypton, and xenon. Some of these gases have lower condensation temperatures than nitrogen. If it is not discharged, it will accumulate at the top of the plate-fin heat exchanger, reducing the heat exchange area.
The main gas discharged is the non-condensable helium-neon, in order to increase the heat exchange area of the primary coolant///
Only two meters? We need 8.9 meters, excluding the non-condensable gas, to increase the heat exchange area
Helium and neon are both non-condensable gases at this pressure and temperature. If no measures are taken to remove these non-condensable gases, they will occupy the heat exchange area on the nitrogen side of the condensing evaporator, thereby affecting the condensation of nitrogen. Therefore, helium and neon purge lines must be installed at the top of the condensation evaporator.