聚丙烯装置二闪线技术改造

Revamp of the second flash pipeline in polypropylene plant

3×105t·a-1聚丙烯(PP)装置投产运行后,当生产均聚和无规共聚物时,丙烯回收系统中二闪线屡次发生堵塞,导致整个高压丙烯回收系统瘫痪,装置被迫停车。为保证装置长周期平稳运行,分析了聚丙烯装置二闪线发生堵塞的原因,即垂直管中气力输送的细粉颗粒出现了噎塞现象,提出了解决此问题的技术改造措施。二闪线在变径前增加一个三通阀,在生产均聚和无规共聚物时,采用将80mm管线不变径,直接进入袋式过滤器F-301,在抗冲共聚生产时,三通阀切向变径管线。二闪线技改后可以有效减少堵塞现象,降低装置非计划停车风险。

When the device is producing homopolymerization and random copolymer, the second flash pipeline in early start-up of polypropylene （PP）plant meet the plugging frequently, the productivity is 3 ×10^5t·a^-1. The plugging of the pipeline causes the paralysis of the whole propylene high pressure recovery systems and the shutdown of the plant under compulsion. To ensure the long-term operation,the reasons for the plugging of the second flash pipeline are analyzed. Powder particles are choking in vertical pipeline in pneumatic transportation. The technical improvement measures are put forward in order to solve the problems. A three-way valve is added in the second flash pipeline in front of the variable-diameter. When producing homopolymerization and random copolymer, the 80mm in diameter of the pipeline is constant and is connected into the F-301 directly. When producing impact copolymer,the three-way valve is switched to the variable-diameter of the pipeline. After technical revamp, the blocking phenomenon in the second flash pipeline is decreased, the risk of unplanned shut-down is reduced at the same time.