脱硫塔圆锥体断裂原因分析  

Analysis on Fracture of the Cone of the Desulfurization Tower

作　　者：董登超 张继明 关云 胡显军 Dong Dengchao;Zhang Jiming;Guan Yun;Hu Xianjun(Institute of Research of Iron and Steel,Jiangsu Province and Sha-Steel,Co.,Ltd.,Zhangjiagang,Jiangsu 215625,China)

机构地区：[1]江苏省(沙钢)钢铁研究院,江苏张家港215625

出　　处：《化工设备与管道》2024年第3期54-58,共5页Process Equipment & Piping

摘　　要：利用金相、扫描电镜和X射线衍射等分析手段,对原料烧结厂脱硫塔圆锥体脱落的原因进行了分析,结果表明,由于脱硫灰附着在脱硫塔圆锥体内壁上,烟气中的水汽在圆锥体内壁形成冷凝水,烟气中或烟气经ClO_(2)气体氧化后反应生成的腐蚀成分溶入冷凝水,形成电解质,渗入脱硫灰中,使脱硫塔圆锥体钢板内壁产生电化学腐蚀;由于脱硫塔圆锥体材质为Q235普碳钢,不具有耐蚀性,导致在钢板内壁形成较厚的腐蚀产物,与脱硫灰附着物在脱硫塔内壁形成结垢,进一步发生缝隙腐蚀,烟气与氧化剂ClO_(2)气体反应生成的Cl^(-),与烟气中自带的Cl^(-)一起,加速了脱硫塔腐蚀进程。最终使得圆锥体钢板不断腐蚀减薄,导致其承重能力下降,当承重能力低于圆锥体自身重量时,圆锥体断裂并脱落。The reasons for the shedding of the cone of the desulfurization tower in the raw material sintering plant was investigated by metallography,scanning electron microscope and x-ray diffraction.The results showed that the water vapor in the flue gas forms condensed water on the inner wall of the cone,and the corrosive components in the flue gas or after the flue gas is oxidized by ClO_(2) gas dissolve into the condensed water to form electrolyte.The electrolyte penetrates into the desulfurization ash which is attached to the inner wall of the cone of the desulfurization tower,causing electrochemical corrosion to the inner wall of the steel plate of the desulfurization tower;Since the material of the desulfurization tower cone is Q235 plain carbon steel,it has no corrosion resistance,resulting in the formation of thicker corrosion products on the inner wall of the steel plate of the cone of the desulfurization tower,together with the desulfurization ash form scaling on the inner wall of the desulfurization tower,and further crevice corrosion occurs.The Cl^(-)generated by the reaction of the flue gas and the oxidant ClO_(2) gas,together with the Cl^(-)in the flue gas,accelerates the corrosion process of the desulfurization tower.Eventually,the steel plate of the cone is continuously corroded and thinned,resulting in a decrease in its load-bearing capacity.When the load-bearing capacity is lower than the weight of the cone itself,the cone breaks and falls off.

关 键 词：脱硫脱硝 脱硫塔 FOSS工艺 电化学腐蚀 缝隙腐蚀 

分 类 号：TG172[金属学及工艺—金属表面处理]