废碱法烟气脱硫吸收塔和烟囱的腐蚀与防护

Corrosion of Absorption Tower and Stack of Spent Caustic Flue Gas Desulphurization and Protection

为了达到"以废制废"保护环境的目的,石化企业热电厂采用乙烯装置产生的废碱液作为脱硫剂,来达到防腐蚀的目的。通过废碱和烟气对碳钢设备的腐蚀机理以及不同防腐蚀材料的特点进行了分析。选择吸收塔内壁采用2 mm玻璃鳞片树脂、矩形管支架采用4 mm预硫化橡胶板衬胶和烟囱采用2 mm钛金属板衬里的防腐蚀组合方案。经过1.5 a的运行,吸收塔玻璃鳞片外观检查无鼓泡、起皮等现象,整体完好;衬胶外观整体完好,没有鼓泡,搭边翘起等现象;烟囱钛板衬里无开裂、腐蚀等现象。各项检测结果均在合格范围内,表明该方案的防护效果明显是"烟塔合一"结构脱硫设备腐蚀与防护的一套可靠的解决方案。

To realize the objectives of ＂processing wastes by wastes＂ and protecting environment, the spent caustic produced in the ethylene plant is used as desulfurization agent in thermo power station of a petrochemical company to prevent the corrosion. By analyzing the corrosion mechanisms of spent caustic and flue gas on carbon steel equipment and corrosions of different materials, a combination process of corrosion protection is adopted by selecting 2 mm glass flake coaling for the internal wail of absorption tower, applying 4 mm pre - sulfided rubber for pipe support and installing 2 mm Ti steel lining for the stack. After 1. 5 years＇ operation, no bubbling and peeling have been found on the glass scale, the pre - sulfiede rubber of pipe support are in good conditions and there are no cracking and corrosion of Ti plate lining of stack. All testing data are within the required specifications. The results show that the combination process of corrosion protection is an effective and reliable solution to protect the corrosion in tower and stack.