Switching heat exchanger of air separation plantThe most likely place to leak is the weld seam, especially the joint of the head and the pipeline. Most of the causes of leakage are the quality problems of manufacture and installation, which are also related to maintenance.Switching heat exchangerThe working condition is poor, not only affected by alternating airflow, but also the airflow temperature changes a lot, in the long-term operation, the weak parts are easy to cause leakage.
Therefore, the welding quality should be strictly guaranteed during manufacture and installation. After installation, strict leak detection and pressure test must be carried out before driving, and problems should be dealt with timely to avoid passivity after driving.
Check in operationSwitching heat exchangerThere are three ways of leakage or not:
1) flow method. When a large amount of leakage occurs between the channel of product oxygen or product nitrogen and air channel, the output of oxygen or nitrogen increases obviously. The air intake should also increase. At the same time, the air pressure decreases and the upper tower pressure increases.
2) purity method. When there is a small amount of leakage between the oxygen and nitrogen channels of the products and the air channels, it can be judged by the results of the product purity analysisSwitching heat exchangerThe purity of the product declines.
3) temperature method. When leakage occurs between the air channel and the sewage and nitrogen channel, the temperature in the middle part will change obviously, and it can be judged from the temperature change which unit has the leakage. Moreover, the air intake will also increase.
Repair welding should be conducted after identifying the leakage parts. If there is an internal leakage in a single channel, the channel can be sealed. If the serious leakage cannot be solved, replace thisHeat exchangerUnit.
