文档介绍：锅炉EDTA清洗工艺条件探讨
Scientific Journal of Frontier Chemical Development
June 2013, Volume 3, Issue 2, -41
Discussing of Boiler EDTA Cleaning Technics Conditions
Ruimin Wang 1,2, Shouhui Zhang 2, Xuejun Xie 1
1. Wuhan University, 430072
2. Xiangyang Power Plant, 441141
Email: xiexuejun@
Abstract
The priciple and technics of the chemical cleaning with EDTA, the choice and control of technological conditions (including the concentration of EDTA, the temperature, the pH value, the velocity of flow and the cleanin-g time), the judgement on the ultimate cleaning and passivation, and the technological supervision of the chemical cleaning with the EDTA ammonium and sodium salt were illustrated. Chemical cleaning were characterized with simplicity, wide range, safety and shorter time spent in cleaning. In practice, the factors affecting EDTA cleaning performance, including the parameters such as, cleaner temperature, concentration, pH, flow rate; as well as the process of cleaning and the optimal cleaning to achieve the best cleaning performance. The #5 new-built boiler adopting EDTA ammonium salt as cleaner in the power plant is a good example of this case.
Keywords: Boiler; Chemical Cleaning; EDTA
王瑞民1,2,张首会2,谢学军1
1. 武汉大学,武汉430072
2. 襄阳电厂,襄阳441141
摘要:本文介绍了EDTA化学清洗的原理、工艺,EDTA钠盐和铵盐清洗工艺条件(包括EDTA浓度、温度、pH值、流速、清洗时间)的选择、控制,清洗、钝化终点的判断,清洗过程中的技术监督;也介绍了某电厂#5新建锅炉采用EDTA铵盐清洗的清洗范围、清洗回路、清洗工艺参数、清洗效果。认为EDTA清洗具有工艺简便,清洗范围大,腐蚀速率小,清洗时间较短和对人身、设备安全可靠等特点;实际清洗中,应科学而严格地控制好影响EDTA清洗质量的因素,包括清洗液温度、浓度、pH、流速等参数,并在清洗过程中切实做好化学监督,控制最佳的清洗工艺,保证化学清洗达到最优效果。该电厂#5新建锅炉采用EDTA铵盐清洗取得了良好效果。
关键词:锅炉,化学清洗,EDTA
概述
新建锅炉在投运前必须进行化学清洗,运行一定时间后也必须进行化学清洗[1]。某电厂二期工程装机为2×600MW机组,其#5炉是上海锅炉厂引进技术制造的国产超临界参数、变压运行、螺旋管圈直流锅炉,型号为SG1913/-M957。
#5炉的此次化学清洗,为建成投产后的第一次清洗,主要清洗启动分离器、水冷壁、省煤器、高加及其管道,具体清洗范围如表1。
清洗回路为:前置泵→#3~#1高压加热器→给水操作台→省煤器→水冷壁→启动分离器→前置泵。考虑到工期紧张和EDTA清洗具有临时系统与清洗工艺简单、清洗时间短、安全可靠、清洗效果好、废
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液可回收等优点,、钝化一步到位[2-12],因而决定#5炉化学清洗采用EDTA清洗工艺。
表1 #5炉的清洗范围
序号
1 2 3