Abstract:

High outlet pressure of the fourth section of cracked gas compressor in ethylene plant can easily cause the safety valve of the discharge tank of the fourth section to jump, leading to fluctuations in production operation. Yanshan Petrochemical started to periodically use cracked kerosene as feedstock in this operation cycle, and a continuous increase in outlet pressure and temperature of the cracked gas compressor was observed at the end of the operation, which led to a continuous decrease in the outlet flow rate of the fifth section, seriously affecting the smooth operation of the plant. Through partial maintenance, it was determined that serious coking inside the high-pressure cylinder of the compressor led to the seal failure of balance disk, allowing the leakage of process gas from high-pressure section to low-pressure section, which was the main reason for the high outlet pressure of the fourth section. Some optimization and improvement measures were put forward to ensure the smooth operation of the ethylene plant for a long period of time.

Key words: cracked gas compressor, outlet pressure, balance disk;coking