锅炉氮气循环氢氟酸清洗新工艺

Nitrogen Circulating HF Acid Cleaning--A New Boiler Acid Cleaning Process

本文介绍一种锅炉酸洗新工艺——氮气循环氢氟酸酸洗。该工艺介于静泡酸洗与流动酸洗之间,其特点是将氢氟酸充满锅炉后由下降管底部通入氮气对水冷壁进行搅拌,达到清洗效果。省煤器则通过清洗泵的循环来达到清洗目的。碱洗及水冲洗时用压缩空气代替氮气进行搅拌,钝化液为亚硝酸钠碱性溶液(用氨水调整pH),并以柠檬酸作为隐蔽剂。该工艺具有不需划分回路、系统简单、安装方便、易于操作等优点。本工艺系国内首次使用于利港电厂的Foster Wheeler 1160t/h亚临界自然循环锅炉上。

A new boiler acid cleaning process--nitrogen circulating HF acid cleaning is described in this pa- per. Being a compromise betweem acid soaking and pump circulation, this process features a nitrogen injection at the bottom of the boiler downcommer to perform the acid cleaning by mixing the HF solution in the water- wall tubing while the economizer cleaning is completed by pump circulation of the acid. Compressed air is used instead of nitrogen in alkali boiling and water flushing. The passivating solution for the boiler metal surface is an alkali NaNO_2 solution (pH-adjusted by NH_3) with citric acid as iron complexant. The process has the ad- vantages of simple, non-loop, deviding of piping system and easy in installation and operation. This procedure is first used in this country on a 1160t/h Foster Wheeler boiler in Ligang Power Plant.