Analysis of the causes of corrosion in boiler economizers
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Which expert has come across this situation with a boiler economizer? What usually causes it? Thank you for your advice!
The metal surface of the boiler economizer is generally subject to dew point corrosion caused by low-temperature flue gas, which is also a type of electrochemical corrosion. The specific causes of corrosion can be analyzed based on factors such as the composition of the flue gas and temperature, so that appropriate anti-corrosion measures can be selected.
The economizer and air preheater of boilers are prone to corrosion, which is mainly determined by temperature and the medium. Dew point and acidic corrosion are common issues; the typical service life is 1 to 5 years. In response to this situation, many refineries have adopted the approach of changing the material used for the heat exchange tubes – mainly steel developed by the Shanghai Institute of Materials, produced by a steel pipe factory in Jiangsu. The price might be 30% higher, but the lifespan can be extended by 2 to 3 times, so it’s still a good deal.
The boiler operates at low load for extended periods, resulting in a low flue gas temperature; the reasons were explained above.
Could you introduce the operating conditions of the economizer?