A brief analysis of materials selection for anti-corrosion on the inner wall of chimneys!

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This post was last edited by www.jsycyn.com on 2012-2-28 at 17:44. Since the use of GGHs was discontinued in wet flue gas desulfurization, the emission temperature of flue gas dropped to 40–50°C, and the pH value of the condensed acid inside the chimneys was 2–3. As a result, corrosion protection became an important aspect of engineering work that needed to be addressed. The large number of such corrosion protection projects attracted manufacturers of corrosion-resistant materials from both domestic and foreign countries. In a short period of time, many corrosion protection products emerged in China, including coating types such as polyurea, glass flake coatings, and OM coatings； There are clay-based products, such as SL300 special acid-resistant clay, Savijin clay, Guster clay, and others ； There are glass brick products such as foam glass bricks and foam ceramic bricks. After numerous evaluations and comparisons by experts, improvements were made continuously through trial and error, leading to the current situation. In 2007, anti-corrosion measures were first introduced; coating products, due to their low cost (200–400 yuan per square meter) and short installation time (20 days), quickly became the main alternative for chimney anti-corrosion purposes, and they were used in almost all chimney anti-corrosion projects that year. However, once the chimneys coated in this way were put into use and exposed to wet flue gas, problems such as coating peeling and chimney leakage occurred in all cases without exception. This reality led experts to shift their focus when selecting materials for chimney anti-corrosion. In 2008, experts shifted their focus from coatings to mortar and glass bricks as materials for chimney corrosion protection. That year, mortar and glass bricks accounted for the majority of the market share as the dominant corrosion protection materials, while coating products continued to be used in some projects due to market inertia. By the second half of the year, the results of using mortar and glass bricks for chimney protection became apparent: some cases were successful, while others saw problems such as peeling and leakage, which shocked everyone and left industry professionals confused. In 2009, the Yongji conference brought together experts from across the country, who, based on the effectiveness of chimney corrosion protection, reaffirmed that although glass bricks and SL300 specialty acid-resistant mortar had their shortcomings, they could be used as primary corrosion protection materials for chimneys after improvements were made. Based on this conclusion, almost all of the chimneys in China’s five major power groups were equipped with foam glass bricks and SL300 specialty acid-resistant mortar. In recent years, titanium alloys have gradually come into focus. Their use for corrosion protection of chimneys has a long history internationally, while in China there are not yet many instances of their application. The excellent properties of titanium alloys for this purpose are well recognized; however, due to high costs, they have not been widely adopted. Summary: Theoretically, all of the materials mentioned above can be used for chimney anti-corrosion protection (the material property tables can serve as a reference). Depending on one’s specific circumstances, the principle to follow when selecting a material is that \"the suitable one is the right one.\" Since the anti-corrosion treatment of chimney interiors is carried out manually, the construction methods and skills employed play a significant role in determining the quality of the work. This is just my personal opinion; if you’re interested, feel free to share your thoughts and give me some guidance! (Please send a message within the site or via QQ.)