Air separation plant maintenance and repair

The expansion air volume entering the upper tower increases, and the reflux ratio of the distillation section decreases correspondingly. In order to achieve the required purity of nitrogen products, more tower plates need to be set. When the reflux ratio is reduced to countless Tower plates needed to be set to make the purity of nitrogen reach the required value, then the reflux ratio is called the minimum reflux ratio. The expansion air volume entering the upper tower is first limited by the minimum reflux ratio. The closer the reflux ratio is to the minimum reflux ratio, the faster the number of tower plates needed to ensure the product purity increases, which will lead to the increase of investment, the increase of tower plate resistance, the increase of Operation pressure and the increase of energy consumption. Therefore, the reflux ratio after the inflated air enters the tower should be larger than the minimum reflux ratio. When the purity of nitrogen is required to be low, the...

In the switching heat exchanger, moisture and carbon dioxide cannot be completely and thoroughly removed. Although the remaining amount is very small, it will gradually block the switching heat exchanger over time. In the production, it shows that the resistance of switching heat exchanger increases continuously, the free section of gas flow decreases, and the air volume cannot enter. In addition, in the cold section of the switching heat exchanger, carbon dioxide has been basically cleaned up theoretically, but due to the clamping effect of air flow, the amount of carbon dioxide brought into the tower is much more than the theoretical content. Apart from being partially cleared by the adsorption filter, the rest of the carbon dioxide will gradually accumulate in the tower and block the tower plates, pipelines and valves. In addition, the air also contains a small amount of acetylene and hydrocarbon. Although adsorbed by acetylene adsorber, its adsorption efficiency can only reach a...