Factors influencing the heat exchanger of the large air separation unit

There are 10 ways to transilluminate the welding seam of air separation unit, which are suitable for different occasions. Single wall is the most commonly used transilluminating method, but when the radiation source or film cannot enter the inside small diameter vessel and pipeline, double wall transilluminating method is adopted. The selection of transillumination method should consider all factors synthetically. For example, according to the principle of selecting the transillumination method which is beneficial and improves the sensitivity, single wall transillumination should be selected as far as possible. According to the principle which is conducive to the detection of corresponding defects, the outside radiation source is preferred for the detection of cracks on the inner wall of the container.

If the temperature after the expander of the air separation unit is too low, it should find out the cause of the low temperature and take measures to increase the temperature after the expander. If the low temperature of expander is caused by liquid air in front of expander, appropriate measures should be taken to reduce the liquid air level of lower column. If it is caused by other reasons, the more effective method is generally throttling in front of the expander. Throttling will not increase the temperature in front of the expander, but throttling will reduce the pressure in front of the expander, so the pressure difference between the front and the back of the expander will be reduced, the expander will do less work and the temperature will be reduced, so the temperature at the after of the expander can be increased.