On the corrosion issue of heat exchangers using liquefied gas
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The heat exchanger media in my workshop are liquefied gas and circulating water; currently, many parameters of the circulating water do not meet the standards, and it has been determined that there is a leak of liquefied gas. I would like to ask the more experienced colleagues: what material should be used for the heat exchanger tubes in order to effectively prevent corrosion? Are there any other methods as well? I appreciate any advice you can provide.
The heat exchanger tube bundle should be made of stainless steel to effectively prevent corrosion
It is likely due to circulating water corrosion; it is recommended to upgrade the heat exchanger tube bundle
Carbon steel + circulating water side coating for corrosion protection.
In chemical engineering design, carbon steel is generally the preferred material, mainly due to its excellent cost-performance ratio. In situations with harsh operating conditions, coating methods are often used to prevent corrosion, and the cost of such approaches is usually lower than that of using stainless steel! However, when using coatings for corrosion protection, the quality of the coating must be ensured; otherwise, the desired results will not be achieved!
Temperature, tube side, shell side, material – in more detail!
If the chloride ion concentration in the circulating water is less than 25 ppm, what is the H2S content in the liquefied gas? Corrosion occurs very easily during the phase change process.
Based on your description, the quality of the circulating water does not meet the requirements; therefore, anti-corrosion coating is needed on both the circulating water side and the liquefied gas side. It is completely feasible to use carbon steel for such equipment, and there are already many examples of this in practice.