Abstract: In view of the harsh process conditions of ethylene spherical tank that needs to be pre-cooled to below -30℃ before receiving materials and the safety and environmental protection risks of the pre-cooling operation, on the basis of theoretical analysis and feasibility, it is proposed to change the pre-cooling method from "bottom tube inlet" to "top spraying droplets" in view of the harsh process conditions of ethylene spherical tank that need to be pre-cooled to below -30°C before receiving materials and putting them into use. It has been proved in practice that the pre-cooling method of spraying droplets on the top shortens the pre-cooling time of the spherical tank from 56 hours to 12 hours, reduces the emission of volatile organic compounds (VOCs) such as ethylene to the flare by about 30 tons, and achieves the purpose of carbon emission reduction and cleaner production. At the same time, it also eliminates the safety and environmental protection risks caused by the brittle leakage of spherical tank material caused by the large temperature difference between the top and bottom of the tank.

Key words: Low-temperature ethylene spherical tank, Pre-cooling, Difference of temperature, Brittle leakag, VOCs