PTA装置氧化干燥机壳体腐蚀及对策

Corrosion on Shell of PTA Oxidation Dryer BM302 and Countermeasures

中国石油化工股份有限公司洛阳分公司精对笨二甲酸装置的氧化干燥机在运行6a后壳体出现了腐蚀穿孔。经对腐蚀穿孔原因进行认真分析,认为主要原因是装置扩能后进入干燥机内介质所带的腐蚀性物质的质量分数增高及碱洗频率增加所致。针对氧化干燥机壳体腐蚀严重的情况,建议采用特种不锈钢(如317 L等)或内壁采用钛复合层可使腐蚀问题得到缓解。

Oxidation dryer in PTA unit in SINOPEC Luoyang Petrochemical Company experienced corrosion failure in the shell after 6 years＇operation. The detailed analysis of corrosion failure has found that the corrosion was caused by increased amount of corrosive materials carried over into the dryer after unit expansion and increased caustic washing frequencies. To solve this problem, it is suggested to select special stainless steels （such as 317L, etc. ） or apply Ti composite coating on the internal wall of the shell to bring the corrosion under control.