聚丙烯装置动力分离器密封失效分析与改进

摘要

Aiming at the problems of frequent leakage and short service life of the mechanical seal in the power separator of polypropylene plant, this paper found that the high operating temperature of the sealing oil is the main reason for the short service life of the mechanical seal through analysis and calculation of the seal failure factors.The sealing oil circulation system was optimized by increasing the heat exchange area of the sealing oil heat exchanger and reducing the clearance of the screw sleeve of the pump.After one year of operation, the inlet sealing oil temperature of the sealing chamber of the power separator remained at 35 to 40 degrees and the leakage amount of sealing oil was basically stable at 0.3 L per day.This optimization and transformation solved the problems of frequent leakage of mechanical seal of power separator, lengthened the service life of mechanical seal, reduced the number of shutdown times of the device, avoided the environmental pollution caused by plenty of seal oil leakage, and also created certain economic benefits for polypropylene plant.%针对聚丙烯装置动力分离器机械密封频繁泄漏、寿命较短的问题,通过对密封失效因素的分析计算发现,密封油运行温度过高是造成机械密封寿命较短的主要原因.采取增加密封油换热器换热面积、减小泵送螺旋套间隙等手段优化密封油循环系统并运行1年后,该动力分离器密封腔进口密封油温度维持在35～40℃,密封油泄漏量基本稳定在0.3L/d.本次优化改造解决了动力分离器机械密封经常性泄漏的问题,延长了机械密封的使用寿命,减少了装置停工次数,避免了密封油大量泄漏对环境造成的污染,同时也为聚丙烯装置创造了一定的经济效益.