The heat exchangers used in polysilicon production are suffering from severe leakage – what are some good solutions?
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Dear colleagues, heat exchangers in the polysilicon production process are experiencing frequent leaks, especially those used in cold hydrogenation distillation, which affects normal production. Do you have any effective solutions to this problem? Has anyone used heat exchangers with anti-corrosion coatings? What was the performance like?
What material is the tube bundle of your heat exchanger made of?
Just replace it with a new one; the heat exchange efficiency of those treated to prevent corrosion is not very good
What is the specific form of the leakage? Are there any medium properties? If it is a tube sheet type, with cracks or holes in the tubes, it is usually a material issue. Cracks at the tube sheet are usually caused by manufacturing issues (insufficient tube sheet thickness, too small a spacing, poor welding). If the medium is corrosive, it may be a problem with the material selection, as well as the design operating temperature – whether it exceeds the permissible limit. Only by identifying the problem can one decide on the course of action, whether it is repair or replacement
Carbon steel is the main material, with occasional leaks occurring in stainless steel as well.
If you don’t replace it with a new one, those that have been treated may not leak for now, but once they are put into use, the possibility of leakage is very high, and the costs outweigh the benefits.
The heat exchangers we use here are made of white steel, and the likelihood of problems occurring is very low. Please consider this from the perspectives of design and the quality of the heat exchangers
Apply polymer coating to the heat exchanger, and it will work fine for 10 years.
The main cause of leakage in cold hydrogenation heat exchangers is stress corrosion caused by chloride ions; this is primarily due to issues with the design and manufacturing processes. For example, the double-shell heat exchangers designed by Chengda suffer from design-related problems
The designs and equipment produced by that design institute or manufacturer are of better quality