焦炉烟气脱硫脱硝系统热管换热器腐蚀原因分析

针对迁安中化公司焦炉烟气脱硫脱硝系统热管换热器腐蚀的问题,对换热器低温段炉管及翅片的腐蚀产物进行了XRD、扫描电镜、能谱分析,结果表明,炉管及翅片发生了严重氧腐蚀、轻微硫腐蚀和氯腐蚀。分析认为腐蚀与经脱硫脱硝系统后烟气中含有体积分数6%~10%的O2和15%~20%的水分有关,建议将热管换热器低温段材质更换为耐氧、硫腐蚀的2205不锈钢,以满足脱硫脱硝系统的长期稳定运行。

Corrosion Analysis of Heat Pipe Exchanger in Flue Gas Desulfurization and Denitrification System of Coke Oven

In view of the corrosion of heat pipe exchanger in flue gas desulfurization and denitrification system of coke oven of Qian′an Zhonghua Company,the corrosion products of the furnace tube and fins in the low temperature section of the heat pipe exchanger were analyzed by SEM,EDS and XRD,which showed that serious oxygen corrosion,slight sulfur corrosion and chlorine corrosion occurred in the furnace tube and fins.The analysis believed that the corrosion was related to the fact that the flue gas of coke oven contained 6%-10%O2 and 15%-20%moisture after desulfurization and denitrification system.It was recommended to replace the low temperature section material of the heat pipe exchanger with 2205 stainless steel which was resistant to oxygen and sulfur corrosion to meet the long-term stable operation of the desulfurization and denitrification system.