What are the reasons for nitrogen blockage in the crude argon column and the methods for operational adjustments? Do anyone have any suggestions?
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Nitrogen plugging is a common issue during operation, caused by the accumulation of nitrogen in the coarse argon condenser, which prevents argon from condensing. Do you have any preventive methods, and how can AI and TI be used to detect and address issues in a timely manner? Thank you!
As for such issues, my view is this: you are right; prevention should be the priority. Once it happens, there’s basically nothing that can be done about it. And then there’s prevention. As for how to prevent it, the key lies in operational control. Many are caused by the desire for high output in terms of superpowers. Focusing only on high output, ignoring the basic requirements of the manufacturing process. During operation, the production conditions are usually adjusted to their extreme limits at night; by morning, as the air temperature rises, the relative process conditions deteriorate, yet the output remains unchanged. This can lead to the possibility of a nitrogen plug. As for how to prevent it, I think the first step is to do a good job of limiting production capacity, and it’s essential to operate with some margin for flexibility. In fact, the impact of nitrogen saturation on production during this period offsets, or even exceeds, the costs incurred to achieve high yields; in some cases, it can be even higher. Although my explanation is not supported by specific data, it is a matter that deserves serious attention. This is not only to address the nitrogen clogging issue, but it also relates to the impact of other products (for reference)
A high nitrogen content in the argon fraction causes nitrogen to accumulate, preventing it from being liquefied in the crude argon condenser and resulting in a nitrogen plug. When this occurs, the heat transfer temperature difference in the crude argon condenser decreases, the amount of argon vapor that liquefies is significantly reduced, the resistance in the crude argon column falls, and the liquid oxygen in the crude argon condenser cannot evaporate, resulting in an increase in the liquid level. When a nitrogen plug occurs, the following measures should be taken: ① Reduce the liquid air injection valve in the crude argon column to lower the liquid level of liquid air in that column; ② Decrease the amount of product oxygen taken out, thereby increasing the oxygen content in the argon fraction. This helps to facilitate nitrogen removal from the crude argon condenser and raise the temperature of the argon vapor, accelerating the evaporation of liquid air and allowing the liquid level to return to normal as soon as possible; ③ Open the vent valve of the crude argon column to release nitrogen. This not only prevents the accumulation of nitrogen but also enhances heat exchange in the crude argon condenser, helping to bring the liquid air level back to normal. If the above methods are ineffective, the crude argon column can only be temporarily shut down; it can be restarted once the conditions in the main column stabilize. Preventive measures: To avoid nitrogen plugging in the crude argon condenser, the following three points should be observed during operation: ① Ensure that the argon content in the argon fraction is 8% to 10%, the oxygen content is 90% to 91%, and the nitrogen content is less than 0.1%; ② Prevent large fluctuations in the level of the main cooling liquid; ③ The pressure in the upper column should not increase too rapidly. In short, the operating conditions of the main tower must remain stable, with no significant adjustments made, to ensure that the contents of various components in the argon fraction stay within normal ranges.
There’s no really good solution~~ Just practice more and draw more conclusions~~ to figure out which factor best indicates the onset of nitrogen embolism； Identify the operating conditions in which nitrogen plugging is likely to occur, etc~~
Pay close attention to the temperature, especially at the argon extraction point.
What temperature do you normally keep it at?
Our low-pressure tower is equipped with a temperature point that can be used for reference and control; special attention should be paid when the temperature is low!
What is the normal control range for this temperature?
What is the normal control range for this temperature?
We set the temperature at -187 degrees Celsius; usually, when it reaches around -187.7 degrees, the nitrogen level drops!
We set the pressure of the low-pressure tower at 0.32 kg/cm2