Regarding the role of V11
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Is the main function of V11 to adjust the load of the air separation unit, or to regulate the purity of the liquid oxygen? I would appreciate the help of experts. Thank you
V11 is the lower reflux liquid valve, used for purification.
These days, many designs no longer include a reflux V11 valve; those that do exist are used only during startup, remaining fully open under normal conditions, and the purity of the liquid nitrogen can be completely controlled through the valve for feeding liquid nitrogen into the upper tower~~
Generally, the tower operating conditions are adjusted when starting the vehicle; under normal circumstances, they are set to full open! ~
If it is under normal operating conditions, I need to reduce the load now – do you control V11? Our equipment is from Hangyang; it’s a 1-to-2 unit with an internal compression process
Personally, I think to reduce the load, there is no need to adjust V11; we usually adjust v3 instead. I also have Hangyang equipment here
Many devices are adjusted to V3, while V11 remains basically at full open~~
With Hangyang’s equipment, it basically operates at full capacity once the temperature reaches around 50 degrees. To adjust the load, we generally don’t touch valve 11 or make only minor adjustments; instead, we just adjust the liquid nitrogen throttle valve
In my opinion, V11 can be used to adjust both the load and the purity, but it cannot rely solely on V11 – V11 plays a leading role only; the actual adjustment of the load and purity still depends on the throttle valves in the upper and lower towers. However, if the opening degree of V11 is reduced, it will definitely affect the air separation load, and no other valves can compensate for this effect. The degree of opening of V11 reflects the magnitude of the main cooling load; generally, some people leave it fully open, but such a practice is not very scientific as it increases energy consumption. The optimal opening degree for V11 is: open it until the pressure difference in the lower column stops changing, and then reduce the opening slightly (until there is a slight change in the pressure difference in the lower column). Generally, purification is adjusted using the V3 valve; if purification still needs to be adjusted via V11, it will be designed as a self-regulating valve rather than a manual valve. In fact, many air separation units these days use full reflux in their design, and there is no longer such a V11 valve.