Abstract: After the transformation of the closed decoking system using S-CCHS technology in the 1.2 million t/a delayed coking unit of one company, the problems of single petroleum coke products, high equipment failure rate which affects stable operation of the unit, and high operation and maintenance costs have gradually emerged. By developing special carbon materials for energy storage, establishing technical research team to reduce equipment failure rate, adopting new technologies, preventive maintenance strategies, small-scale technical upgrades, and other measures, the operation of the closed decoking system has been optimized. Through these measures, the objectives of enriching the structure of petroleum coke products, improving device stability, and reducing costs and improving efficiency have been achieved.

Key words: ethylene plant, cracking furnace, steam drum replacement, construction quality control, standardization