Chimney material selection
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The original fiberglass chimney needs to have its material replaced with a high-temperature resistant steel chimney. The flue gas contains small amounts of sulfur dioxide and hydrogen sulfide, and it is also moist; the normal operating temperature ranges from 50 to 120 degrees, while it can reach 180 degrees in emergency situations. What material should be used for the chimney? Additionally, the chimney is 80 meters tall and 2.4 meters in diameter, with two 2.4-meter pipes connected to it, as well as one pipe that is 1.5 meters in diameter
Use ND steel, with glass phosphide flakes applied internally.
If money is no object, titanium-steel composite plates offer better corrosion resistance.
Thank you for your reply. I considered using glass flake coatings on the inside, but since the temperature during the accident was 180 degrees, which is close to the limit for ordinary glass flakes, I’m concerned that this will shorten the already short service life of those glass flakes
Titanium-lined carbon steel composite plates were also considered; several equipment manufacturers were consulted, and all said they had no experience dealing with pipes of such large size. The largest pipes have the same diameter as chimneys, and lining them in areas where connections are present is indeed difficult
The temperature under accident conditions can be reduced by using nitrogen injection or ventilation as a temporary solution. Moreover, since the duration of accidental emissions is short, the damage to the glass flake coating is not severe, and it can be repaired during regular shutdown maintenance periods.
A diameter of 2.4 meters is not considered very large; there are several examples of titanium composite panel chimneys in China, but they are too expensive.
The tee can be directly made from titanium sheet.
I have seen an SO2 chimney with a diameter of 1.8 meters and a height of 180 meters; it is made of Q345NH material (with 316L material used for the upper 2 meters), its inner wall is lined with lightweight acid-resistant lining material, and its walls are coated with acid-resistant paint. As a result, after one year of use, ring-shaped pitting corrosion occurred on the cylinder, and the performance was very poor.
In FGD systems, anti-corrosive coatings that are resistant to flue gas, corrosion, and high temperatures can be used. If there is a metal-nanopolymer alloy anti-corrosion coating, it will have excellent performance and be suitable for use in such working conditions.
Can fiberglass chimneys not resist corrosion? Logically, there should be no problem using a better quality resin, right?