Regarding the temperature of the expanded air entering the upper tower
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Previously, we inflated air into the upper column at -157.6°C; now it has been adjusted to -151°C. Will this have any impact on the distillation process in the upper column and on the purity of oxygen and nitrogen?
We inflate air into the lower tower. . Why go up the tower? Need high-purity nitrogen?
What kind of space is this? 10,000 m3?
This post was last edited by Yu Weiyou on 2015-11-9 at 11:17. We use an external compression unit of 8000 for our small air separation system
The superheat of the expanded air has a significant impact on the distillation in the upper column; as the temperature rises after expansion, its superheat increases, and the amount of expanded air that can be fed into the upper column decreases. Did you do this on purpose? Has the total amount of expanded air decreased? ~~
The process of feeding expanded air into the upper tower relies primarily on the potential of the distillation section in that tower~~
Is that expanded air inlet above the stripping section? Is this a way to obtain more high-purity nitrogen?
Yes, with proper control, the extraction rates of oxygen and nitrogen can be increased~~
We are KDON: 30,000/60,000 air separation capacity, with an external compression process. Normally, the expanded air goes into the upper tower; if the expanded air goes into the lower tower, isn’t that an internal compression process? Please correct me if I’m wrong – I don’t really understand other processes. An increase in the temperature of the expanded air leads to a decrease in the volume of air, so the oxygen purity in the upper tower should decrease, right? I’m not sure if that’s correct.
For the internal compression process in air separation, regarding the expanded air, it can be fed into the upper or lower tower, and the equipment configuration will vary accordingly. If the superheat of the expanded air increases, it is necessary to determine whether this is due to a fault or as a result of some adjustment. In general, the expanded air should be introduced into the tower as much as possible to participate in the distillation process (under conditions where distillation is feasible), in order to improve the yield of oxygen and nitrogen~~
We did this intentionally, because earlier we increased the oxygen flow rate by 400 cubic meters; since the purity was not sufficient, we increased the amounts of V2 and nitrogen being discharged from the tower. As a result, there was slight liquid suspension in the upper part of the tower, although the expansion volume did not increase. We determined that the heat load on the upper tower was insufficient, and we adopted the method of increasing the intermediate extraction to raise the temperature of the gas entering the upper tower for expansion. Now, even when V2 is turned up to high, there is no more liquid suspension phenomenon. I want to know what impact the temperature of this expanded air has on distillation in the upper column, and how significant that impact is