Delayed coking – Reboiler oil withdrawal
Thread Content
Today, delayed coking was shut down, and the oil removal process from the reboiler at the bottom of the cracking tower and the reboiler at the bottom of the stabilizer is yet another challenge. Since both reboilers are located on the ground, far below the pump discharge outlet at the bottom of the tower, it is very troublesome to drain the oil each time. Both reboilers have oil return lines, but it is known that gasoline must be cooled down when returning it; the heat source in the reboilers has to be removed so that the gasoline can cool down. As a result, the pressure in both columns decreases, which creates a contradiction. Dear sea friends, share your opinions, and also talk about the oil removal routes and methods for your own unit reboilers. Complete the oil removal process more safely.
After it cools down, purge it with nitrogen
Only gasoline should be used for flushing; water or nitrogen will do as well. The gasoline is used to clean the oil lines, and after that, it still cokes up and gets trapped there
Reply to 5# Dongfang Zhi Dong: Gasoline cannot be purged using steam. Since the reboiler and the tower are connected, even when performing purification, steam must be injected into the tower to create pressure and push the gas outward; this is not practical.
Gasoline cannot be dried directly with steam, as this can easily generate static electricity during high-speed flow, posing a risk of accidents; generally, water is used first to remove it.
Every time, I use water to float the oil, and it’s not very troublesome either.