浆液外循环技术在聚乙烯装置上的应用及改进

Application and improvement of slurry outside circulation in polyethylene unit

中国石油辽阳石化公司首次在国内通过采用浆液外循环技术提高聚乙烯装置的生产能力。应用初期，外循环泵和聚合釜需频繁停车清理。经过三个阶段的技术改造和操作条件优化，外循环系统停车次数下降，运行周期上升710h，聚乙烯生产能力比采用浆液外循环技术前平均增加1．7t／h。最佳操作条件：循环量400m^3／h；聚合反应温度大于83℃；外循环出入口温差3-4℃；循环泵出口压力1．2-1．3MPa。

The techniques of slurry outside circulation were applied in Liaoyang Petrochemical Company to improve production capability.At the beginning,circulating pump and reactor had need to shut down and be cleaned frequently.Through 3 stages of technical improvement and optimizing operation conditions,the shutdown times of outside circulation system were reduced,device running time increased 710 h,PE production capability increased 1.7 t/h.Optimized operation conditions were obtained that circulating load was 400 m3/h,polymerization temperature was more than 83 ℃,difference in temperature outside circulation system between inlet and outlet was 3～4 ℃,outlet pressure of circulating pump was 1.2～ 1.3 MPa.