Material selection for chloride corrosion
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With a chloride ion concentration of around 2000 mg/L and a temperature of around 130°C, what material is suitable for use as heat exchange tubes?
It should be titanium; we use titanium quite often for phosphorus trichloride
Graphite heat exchangers are recommended. Graphite heat exchangers can be used for a long time under the boiling point conditions of salts and acids at any concentration, without experiencing corrosion; they are also inexpensive and have good heat transfer properties.
Chemical equipment made of graphite can be manufactured as A4-class pressure vessels; the design pressure for graphite pressure vessels is ≤2.4 MPa, and they can be used within this range.
As far as I know, there are heat exchangers made of fluoropolymer materials, silicon carbide, and graphite – all of which can meet your requirements. However, to determine which one is the best, it depends on other parameters as well. I’d be happy to discuss this further! Thank you!
The process medium flows through the tube side, while the service medium flows through the shell side.
Graphite heat exchangers are definitely problem-free; chloride ions do not cause corrosion to graphite heat exchangers
The tube side carries the process medium at a pressure of around 1.1 Mpa and a temperature of around 130°C, while the shell side contains turbid circulating water; chloride ions are primarily present in this turbid circulating water, at a pressure of around 0.4 Mpa and a temperature of around 50°C.
It is necessary to consider whether the resin coating inside graphite heat exchangers can resist fluoride ion corrosion; the heat transfer efficiency of tetrafluoride heat exchangers is not satisfactory.