Corrosion resistance of titanium to dilute sulfuric acid
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In the production process, 20% 80-degree dilute sulfuric acid is used, and cooling is necessary; titanium heat exchangers were chosen for this purpose. However, corrosion occurred after just 3 months of use. The manufacturer claims that pure titanium cannot withstand high-temperature dilute sulfuric acid – is this true? Which material is better to choose
(1) For Ti material under conditions of 10–30% sulfuric acid at 80°C, the corrosion rate is >1.5 mm/year; it is not suitable as corrosion is severe. (2) For the 654SMo (S32654, 1.4652) super-austenitic stainless steel material, the corrosion rate under conditions of 20% sulfuric acid at 80°C is 0.1 mm/year, which is considered good
Graphite heat exchangers are recommended; when used with 75% sulfuric acid at its boiling point, no corrosion occurs over time. ↓ ↓ ↓
Silicon carbide heat exchangers are recommended; when used for extended periods at boiling points, they do not suffer from corrosion.
Titanium is not suitable for use in sulfuric acid applications; if a metal must be chosen, 904L could be considered under such conditions
If the evaporator is made of graphite, what form will the tubes take?
If the evaporator is made of graphite, what form will the tubes take?
If the evaporator is made of graphite, what form will the tubes take?
We all use those with a steel lining covered in PTFE; even 93% concentrated sulfuric acid poses no problem
The heat exchange tubes are made of silicon carbide, while the shell can be made of carbon steel, lined with enamel, or coated with fluorine. The takeover is connected using flanges.