硝酸装置低压反应水冷器的腐蚀分析及防护对策

Analysis of Corrosion in Low-Pressure Reactor Water Cooler for Nitric Acid Unit and Prevention Countermeasures

介绍了双加压法硝酸装置低压反应水冷器的工况及特性,分析其腐蚀原因和机理。提出了采用内孔焊和加装沸腾酸液过滤装置等防护措施,经实施取得了较好的效果:减少了非计划停车,预计低压反应水冷器使用寿命由4年延长至8年,成品酸平均质量分数由63.87%提高至64.02%,年增产硝酸1 532 t(折纯)。

Work conditions and characteristics are described of low-pressure reactor water cooler in dual-pressure nitric acid unit, and an analysis is made of its corrosion causes and mechanism. Prevention measures are proposed, viz., internal welding and addition of filter for boiling acid solution, and good results are obtained after implementation： a decrease in unscheduled shut-down, the service life of the low-pressure reactor water cooler prolongs from 4 years to 8 years, and the average mass fraction of the product acid increase from 63.87% to 64.02% , with an increase in annual output of 1 532 t of nitric acid （pure acid）.