延迟焦化装置原料油缓冲罐腐蚀原因分析及对策

Corrosion Analysis and Countermeasures of Raw Oil Buffer Tank in Delayed Coking Unit

某炼油厂1.60 Mt/a延迟焦化装置原料油缓冲罐在2016年大检修时发现局部筒体壁厚减薄严重。通过综合分析得出,缓冲罐筒体壁厚减薄主要原因是罐内减压渣油硫含量不断上升使筒体发生低温H_2S-HCl-NH_3-H_2O腐蚀和液面长期波动造成筒体冲刷腐蚀。结合工艺和设备特点,提出了材料升级、工艺防腐蚀等改进措施。

In 2016 overhaul,severe wall thinning problem was discovered in some parts of raw oil buffer tank in a 1. 60 Mt/a delayed coking unit. Based on comprehensive analysis,the problem was resulted from the combined action between low temperature H2S-HCl-NH3-H2 O corrosion due to continuous increase of sulfur content of vacuum residue in the tank,and erosion caused by long-term fluctuation of liquid surface. Combined with the characteristics of technology and equipment,improvement measurements were put forward from two aspects of material upgrading and process corrosion prevention.