Dry absorption process: What material are the exhaust pipelines for the drying cycle tank, the first absorption cycle tank, and the second absorption cycle tank made of? ?
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The exhaust pipes for the three tanks in our dry absorption process are made of 316L stainless steel; they have been in use for over 2 years with no major issues. Recently, the new nicotinic acid production facility was put into operation, and additional exhaust pipes for nicotinic acid were added to the existing system. After being in use for a short time, severe corrosion occurred on the 316L pipes. Dear acid industry professionals, what material are the three-tank exhaust pipelines used in various factories? If there is a nicotinic acid production line, what material are the exhaust pipes in the nicotinic acid circulation tank made of? ?
Our 98 acid exhaust pipes previously used 304 stainless steel tubes, which suffered from rapid corrosion (especially at the weld areas). We tried the following: we placed CPVC pipes inside the HRS steaming and spraying acid removal tank, and directed the steam and spray at those pipes during the acid removal process (three times a week). The pipes were also kept submerged in acid at all times; after one week, the outer surface of the parts that were in contact with the acid turned black, with the thickness of this black layer being limited to the outer surface only. We’ve already thrown away that pipe; sorry, I can’t send the picture.
What material are evacuation pipes made of these days? ? ?
Still 304; planning to switch to CPVC
Well, have you tried it before? We are planning to switch to Frpp material
We decided to switch to CPVC pipes only after conducting CPVC acid resistance tests. Coincidentally, we are also testing FRP paste for filling sand holes in the exhaust pipes. The construction team leader said that the joint between fiberglass and stainless steel is not good, so it may not last long.
Mm-hm, CPVC is better. However, FRPP (a type of plastic) can also meet the production requirements
PVC pipes can be tried, with fiberglass reinforced on the outside.