It suddenly shrank due to a fault in the liquid nitrogen throttle valve. What changes will occur in the oxygen generation unit within two hours?
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This post was last edited by you*n*nyou on 2011-11-13 at 19:50. The air separation unit suddenly reduced its operation due to a fault with the liquid nitrogen throttle valve. What changes will occur in the oxygen generation unit within two hours?
1. The oxygen content in the argon fraction rises and then falls. 2. The pressure and resistance in the lower column increase. 3. The pressure and resistance in the upper column decrease. 4. The liquid air level rises or the liquid oxygen level drops. 5. The purity of liquid air decreases. 6. The purity of liquid oxygen decreases. 7. The resistance in the crude argon column decreases
The operators have gone outside to work, and the supervisors have come to the control room to manually adjust the valves to the same opening degree as before; two hours later, the automated systems returned to their normal operation. If this valve closes suddenly, the pressure in the lower tower will rise; the liquid oxygen throttle valve will open fully, the amount of air available for processing will decrease, the anti-surge valve will activate, the liquid oxygen level will rise sharply, and the crude argon will be completely ruined.
The most obvious signs are an increase in the pressure at the bottom of the tower, a low air volume, and a decrease in nitrogen purity.
Firstly, the pressure in the lower column increases, which makes the air compressor prone to surge. The throttle valve is closed further, while the reflux valve remains unchanged. As a result, the reflux ratio in the distillation section of the upper column decreases, leading to a drop in nitrogen purity. This does not affect the lower column in the short term; however, if liquid nitrogen flows into the lower column within two hours, the liquid level there will rise, which will reduce the purity of the liquid oxygen and thus affect the oxygen purity in the upper column as well. A decrease in the purity of liquid oxygen also leads to a drop in its temperature, affecting the condensation system for crude argon
After such a long time, the argon system is completely ruined, huh