In the commissioning process of argon production system of new air separation plant, due to unstable gas demand and other reasons, the working condition of argon production system is easy to be fluctuated. The following is the analysis and treatment of common faults.
1.The nitrogen content in argon fraction increased
Due to the small extraction amount of nitrogen products and crude nitrogen products, part of nitrogen enters into the argon production system along with argon fraction, resulting in the increase of nitrogen content in argon fraction. As a result, the temperature difference between oxygen enriched liquid air and crude argon in crude argon condenser is reduced, and normal heat exchange cannot be conducted. Finally, the crude argon cannot be condensed and the oxygen enriched liquid air cannot be evaporated. During the adjustment, the extraction amount of crude nitrogen and nitrogen is provided to reduce the outlet pressure of crude nitrogen to maintain normal operation condition of argon production system.
2.The argon content in argon fraction fluctuates greatly
The argon content in argon fraction is affected by many factors, such as oxygen, nitrogen purity and yield, upper column pressure and so on. When the oxygen and nitrogen production is close to the design condition, the fluctuation of argon content in argon fraction can be reduced by properly reducing the upper column pressure.
3.Nitrogen plug failure occurs when argon content is low in argon fraction
First, check the process parameters and pay attention to the changes of product, output, purity and upper column pressure. If the above factors do not change significantly, it is not ruled out that the expansion air volume of the upper column increases. The adjustment method is gradually increasing the amount of expansion air bypass.
To sum up: the operation condition of argon production system is restricted by many factors. Therefore, it is necessary to ensure the stability of argon production system, distinguish the phenomenon and reasons of abnormal working condition, combine the argon production system with the working condition of main column as a whole, carry out targeted troubleshooting, and gradually make each working condition reach relative balance state, so as to ensure stable production.
