全尺寸补偿膜法密封在外浮顶石脑油罐的应用

摘要

通过对外浮顶储罐密封现状的分析,认为现有储罐密封补偿范围小,当油罐变形较大时,密封失效使油面暴露,油气挥发严重,造成环境污染.介绍了全尺寸补偿膜法密封技术原理,其工作补偿范围较宽,在-100~300 mm,可根据油罐变形情况量身定制,确保密封鞋板与罐壁时刻紧密接触.从全尺寸补偿膜法密封技术在石脑油储罐的实际应用效果看,全尺寸补偿膜法密封能够大幅降低罐区挥发性有机化合物泄漏,实现罐区挥发性有机化合物达标排放.石脑油储罐正常运行后,一、二次密封间的油气烃体积分数小于0.1%,远低于石脑油爆炸下限,极大提高了外浮顶储罐运行的安全性.%Seal status of existing external floating roof tanks are analyzed.It is thought that the seal compensation is not enough and seal failure will be occur as the oil tanks subject a larger de-formation,which will result in oil surface exposure,serious oil vapour volatilization in turn.The working principle and characteristics of the full-size compensated membrane seal are introduced. The full-size compensated membrane seal can be adapted to the deformation of the tank in various situations and ensure the close contact between the sealing shoes and the tank wall with a working compensation range from -100 to 300 mm.According to its practical application to naphtha,the full-size compensated membrane seal can reduce volatile organic compound leakage significantly to meet the emission requirement for tank farm.With the use of full-size compensated membrane seal,the vapor concentration betw een the second seal and primary seal is below 0.1% (V/V) which is far less than the lower explosion limit of naphtha in normal tank operation.The tank op-eration safety is largely increased therefore.