Abstract: The cracking furnace of the 220 kt/a ethylene plant of Dushanzi Petrochemical Company has adopted LUMMUS technology from the United States. It has been expanded from 140 kt/a to 220 kt/a since July 2002 and has been in production since then. There are altogether seven cracking furnaces in the ethylene plant. During normal production and operation, six cracking furnaces are in normal operation state, and one cracking furnace is in decoking air standby state, and the decoking air in the standby cracking furnace is completely empty. At present, the tower kettle temperature of the quench water tower is low; the tower kettle provides insufficient heat for heating, and the high temperature of the decoking air in the standby cracking furnace causes high-temperature oxygen corrosion to the furnace tube. In the cracking device, it is proposed to dilute steam in the decoking air standby cracking furnace, and connect the standby cracking furnace with the quench system to recover part of the heat and reduce the risk of high-temperature oxygen corrosion in the furnace tube when the decoking air is in high-temperature standby state, and reduce the emission of high-temperature coke burning gas.

Key words: cracking furnace high-temperature standby, decoking air, high temperature oxygen corrosion, comprehensive energy consumption