电站锅炉E DTA化学清洗时铜离子对金属的腐蚀及其抑制方法的研究  

Research on the Corrosion of Copper Ions to Metals during EDTA Chemical Cleaning of Utility Boilers and Their Inhibition Methods

作　　者：邬梦琳 胡三木 杨栋栋 Wu Menglin;Hu Sanmu;Yang Dongdong(Ningbo Special Equipment Inspection and Research Institute,Ningbo 315000;Hangzhou Mingzhu Environmental Technology Co.,Ltd.,Hangzhou 310000)

机构地区：[1]宁波市特种设备检验研究院,宁波315000 [2]杭州明珠环境科技有限公司,杭州310000

出　　处：《中国特种设备安全》2023年第5期22-25,61,共5页China Special Equipment Safety

摘　　要：EDTA清洗与一般酸洗相比,具有清洗工艺简单、腐蚀速率较低的优点,常被用于高参数锅炉的化学清洗。但在锅炉化学清洗监督检验中发现,部分运行锅炉采用EDTA化学清洗时,腐蚀指示片的腐蚀速率超标。研究发现:腐蚀速率超标的主要原因是炉管沉积物中铜垢含量较高,且铜含量越高,腐蚀速率超标的可能性越大。针对EDTA清洗中铜垢对金属腐蚀的影响及其抑制方法的研究,发现在EDTA清洗液中加入一定量的硫脲,对金属腐蚀有较显著的抑制作用,且在EDTA清洗前预先进行氨洗可明显降低铜离子对金属的腐蚀影响。Compared with general acid cleaning,EDTA cleaning has the advantages of simple cleaning process and low corrosion rate,so it is often used in chemical cleaning of high parameter boilers.However,in the supervision and inspection of boiler chemical cleaning,it is found that when EDTA chemical cleaning is used in some operating boilers,the corrosion rate of the corrosion indicator sheet exceeds the standard.The study finds that the main reason for the corrosion rate exceeding the standard is the high content of copper scale in the furnace tube deposit,and the higher the copper content,the greater the possibility of the corrosion rate exceeding the standard.Based on the study of the effect of copper scale on metal corrosion in EDTA cleaning and its inhibition methods,it is found that adding a certain amount of thiourea to EDTA cleaning solution has a significant inhibitory effect on metal corrosion,and ammonia cleaning before EDTA cleaning can significantly reduce the effect of copper ion on metal corrosion.

关 键 词：EDTA 化学清洗 腐蚀 硫脲 缓蚀 

分 类 号：X933.2[环境科学与工程—安全科学]