空分设备氮气纯度控制分析

Analysis of Nitrogen Purity Control in Air Separation Equipment

在空分设备热开车冷开车调纯阶段、运行工况调节、故障工况处理时,氮气纯度控制是关键因素。以马钢20000 m3/h空分设备为例,叙述空分设备热开车冷开车调纯阶段液氮节流阀调节、氧气氮气污氮气流量、粗氩塔投运、精氩塔投运对氮气纯度影响的原因及控制方法,阐述空分设备处于正常运行状态时分子筛吸附器切换、夏季高温运行工况调节对氮气纯度影响的原因及控制方法,介绍空分设备发生粗氩塔氮塞时对氮气纯度影响的原因及控制方法。

Nitrogen purity control is the key factor in the hot start-up,cold start-up and purity adjustment stage,operation condition adjustment and fault condition treatment of air separation unit.Taking the 20000m3/h air separation plant of Maanshan Iron and Steel Co.,Ltd.as an example,this paper describes the reasons and control methods for the influence of liquid nitrogen throttle valve regulation,oxygen nitrogen sewage nitrogen flow,crude argon tower operation and refined argon tower operation on nitrogen purity during the hot start-up and cold start-up of air separation plant,and expounds the influence of molecular sieve adsorber switching and high temperature operation condition regulation on nitrogen purity during normal operation of air separation plant.The reason and control method of the influence on the nitrogen purity when the nitrogen plug occurs in the crude argon column of the air separation plant are introduced.