What type of heat exchanger is installed in condensing heat recovery systems to counter the corrosive nature of high sulphur content condensate?

In condensing heat recovery systems, the choice of materials for heat exchangers is critical, especially when dealing with condensates that may contain high levels of sulfur. The correct answer here is the use of stainless steel for several reasons related to its composition and properties.

Stainless steel has a high resistance to corrosion, which is particularly important in environments where acidic condensates can form due to the presence of sulfur. When sulfur compounds are present in flue gases, their condensation can lead to the formation of sulfuric acid when combined with moisture. This acidic environment can quickly damage materials that are not specifically designed to resist such corrosive conditions.

Stainless steel also has a good balance of strength and workability, making it suitable for various industrial applications, including heat exchangers where both thermal and mechanical stresses exist. Its ability to withstand high temperatures and various pressure conditions adds to its integrity under operational circumstances.

While other materials like plastic-lined options can offer some level of corrosion resistance, their structural integrity at high temperatures and pressures may not be adequate for heat exchanger applications. Mild steel, without adequate protection, would succumb quickly to the corrosive effects of acidic condensates, leading to premature failure. High alloy steel may have some resistance, but it can be more expensive and