乙烯厂乙烯装置的成品罐区内,有低温贮存的乙烯球罐数个。但当乙烯装置每年一度的大检修期间,由于乙烯球罐从周围大气吸热而蒸发的乙烯汽不能返回装置,使球罐内压力升高,容器会发生危险。要使球罐内压力下降,有二种处理方法:一是将球罐内气体送往火炬系统燃烧排放,这样不仅浪费了乙烯,而且也影响了安全生产。第二种方法是采用冷凝回收法,即 Vinyl plant ethylene plant finished tank area, there are a number of low-temperature storage of vinyl spheres. However, during the annual major overhaul of ethylene plant, ethylene vapors evaporated due to the heat of the vinyl can from the surrounding atmosphere can not be returned to the plant, causing the pressure in the tank to increase, posing a risk to the container. To make the pressure drop within the tank, there are two ways: First, the ball tank gas sent to the flare combustion system emissions, so that not only a waste of ethylene, but also affect the safety in production. The second method is the use of condensation recovery, that is