When there is a leak in the cold box of the air separation tower, the cooling capacity to maintain normal production appears insufficient. Therefore, the main sign is the continuous decrease of the main cooling liquid level.
If a large amount of gas leaks, an increase in pressure inside the cold box can be observed. If the cold box is not tight, a large amount of cold air will emerge from the gap. However, when low-temperature liquid leaks, there is no obvious increase in pressure or gas escape, and a significant decrease in the base temperature can often be measured.
In order to make a preliminary judgment on the leakage location and material before shutdown for maintenance, and to shorten the downtime, the following methods are comprehensively used:
(1) It tests the purity of the gas escaping from the cold box. When nitrogen or liquid nitrogen leaks, the purity of nitrogen reaches over 80%, and when oxygen or liquid oxygen leaks, the purity of oxygen significantly increases.
(2) Observe the "sweating" or "frosting" area on the cold box wall. At this time, pay attention to the "frosting" area located below the leakage point when low-temperature liquid leaks.
(3) Observe if there is any regularity in the escape of gas.
DEAR air separation equipment manufacturing achieves safe operation and maintenance, stable and efficient operation.
