尿素级不锈钢衬里腐蚀规律初探

Preliminary Discussion of Corrosion Pattern of Urea Class Stainless Steel Inner Lining

归纳总结了水溶液全循环工艺尿素合成塔不锈钢内衬的腐蚀规律。研究表明:使用周期超过13年的尿素合成塔内衬均匀腐蚀规律开始分化,个别塔内衬腐蚀加剧明显;一般尿素合成塔中偏上部筒节的剩余壁厚最薄,可通过适当调整该筒节塔盘间距或塔板筛孔数,缩短该处反应时间,改善温度分布,以延长整塔使用寿命;多塔并联运行时,应注意管道阻力不同导致各塔氧含量的不均匀所引发的不均匀腐蚀。

The corrosion law of stainless steel inner lining of urea reactor in aqueous solution total recycle process is summarized. Study indicates that when service cycle is over 13 years, the corrosion pattern of urea reactor inner lining starts to divide, the corrosion of some of the inner lining is increased and obvious ; in general, the residual wall of upper part of cylindrical shell section of urea reactor is the thinnest, by adjusting properly tray spacing of cylindrical shell section or reducing the number of sieve pores, reaction time there can be reduced, and temperature distribution can be improved, prolonging service life of whole reactor; when reactors operated in parallel, uneven corrosion caused by uneven oxygen content of reactors resulted in different of pipe resistances should be noticed.