How can the gas separation unit be purged during its initial startup to ensure a smoother operation?

It’s convenient to replace it with N2 gas; fill and release it several times – the O2 content should be below 0.5% once that is done

The question is simple: Once the through-purge and pressure testing are completed and the unit meets the operating conditions, a thorough inspection of the process must be carried out to ensure that there are no leaks or cross-connections in this forward flow process. 2. Leave a small amount of steam; it is appropriate to monitor the steam at the tower top. Once the steam supply is stopped, slowly introduce liquid hydrocarbons or gas. When no steam is visible at the tower top and the pressure starts to rise, close the vent at the top as well as the valves for introducing liquid hydrocarbons or gas. 3. Maintain the system pressure; assign someone to carry out dehydration at regular intervals. When the pressure drops, it is possible to introduce some gas to help maintain the desired pressure. Advantages: 1. Using nitrogen is expensive, and its pressure levels are also limited; of course, units with better facilities can use nitrogen. 2. This method is convenient and safe. As an additional note, it is best to use liquid hydrocarbons that are transferred from another area; using gas has disadvantages, as non-condensable gases must be continuously discharged after feeding, which affects the progress of operations. Last edited by chengkang on 2009-3-2 19:25

Method for purging the gas system before commissioning: 1. Purge with nitrogen; after pressure testing is completed, purge with nitrogen until the oxygen content is <0.5%； 2. Replace directly with liquefied gas; after pressure testing is completed, purge the gas separation system with steam. Once the gas supply is stopped, immediately introduce liquefied gas into the tower for replacement, and vent it to the flare through the flare bypass until the oxygen content is below 0.5% ； During the displacement, steam and water must be supplied to the reboilers and coolers of each tower to prevent the reboilers and coolers from being damaged by freezing due to the heat absorbed during the vaporization of the liquefied gas.