In air separation units that produce argon through complete distillation, there is a reduced-diameter section above the argon fraction extraction point in the upper column – what is the purpose of this?
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In air separation units that produce argon through complete distillation, there is a reduced-diameter section above the argon fraction extraction point in the upper column – what is the purpose of this? There are a few statements below that I don’t think are quite correct; please help me out with your advice. Save materials, save energy
After the argon fraction is extracted, the upward gas flow above the fraction extraction point decreases; consequently, the diameter of the upper column must be reduced to align with the design principles, not only to save materials.
Ensuring an appropriate reflux ratio is beneficial for the progress of distillation
The upward gas flow above the fractionation outlet decreases, while the reflux liquid volume remains constant; therefore, to maintain the reflux ratio it is necessary to reduce the tower diameter, which also results in less material being used. As for energy consumption, I don’t think there’s any change. Personal opinion, for reference only
Stable reflux ratio, minimal purity variation!
Several people upstairs said that reducing the tower diameter is done to stabilize the reflux ratio. In fact, the reflux ratio is the ratio of the reflux liquid to the rising steam, and it has nothing to do with the tower diameter. I wonder whether those who gave such answers really considered whether it was correct
The diameter of the tower is determined by the amount of material involved in the distillation process, that is, by the load. For example, the tower diameter for an oxygen generator with a capacity of 15,000 is different from that of one with a capacity of 20,000. As is well known, the amount of argon fraction extracted is very large; after the fraction is extracted, the distillation load on the upper column decreases, and therefore the diameter of the upper section of the column also needs to be reduced. This is not unrelated to the reflux ratio; there is an indirect relationship. But one needs to think about it deeply. This post was last edited by Youyou on 2009-4-15 09:20]
The main goal is to ensure the intensity of gas-liquid contact, maintaining it at around 70% of the critical gas velocity, thereby enhancing the efficiency of distillation!
It facilitates the control of the reflux ratio, thereby stabilizing the operating conditions..................