Jiangyin Youtejia Air Treatment Equipment Co., Ltd.

Today, April 24, marks the ninth "World Corrosion Day." The issue of corrosion may seem commonplace to all of us, even something we take for granted. However, Han Enhou, Chairman of the World Corrosion Organization, Director of the National Engineering Research Center for Metal Corrosion Control, and a researcher at the Institute of Metal Research, Chinese Academy of Sciences, pointed out in an interview with central media that corrosion not only contributes to environmental pollution, directly threatening people's quality of life, but also leads to catastrophic accidents, jeopardizing public safety. Moreover, corrosion continuously damages and endangers countless cultural treasures left behind by the Chinese nation. Corrosion is a global challenge faced by humanity as a whole, impacting resource consumption, harming the environment, and affecting human health. In China, the total economic cost of corrosion amounts to approximately 5% of the country’s GDP—far exceeding the combined losses from all natural disasters. For instance, while the 2008 Wenchuan earthquake caused economic damage totaling 850 billion yuan, the same year, corrosion-related losses in China surged to an alarming 1.5 trillion yuan.

Corrosion comes in many forms, and so do the methods to prevent it. For us—this group of dehumidification experts who deal with moisture day in and day out—there’s one type of corrosion that’s particularly relevant: metal corrosion. We know that three conditions are essential for metal corrosion to occur:

Positive and negative electrodes (cathode, anode), electrolyte, oxygen.

Since perfectly pure, single-element substances are virtually nonexistent in nature—especially considering that most metal objects we use are alloys composed of various elements—any presence of even slightly reactive elements will inevitably create positive and negative electrodes. Meanwhile, oxygen from the air is almost everywhere. That’s why the most common method of corrosion prevention involves applying anti-corrosion paint to metal surfaces, effectively isolating the metal from atmospheric oxygen and any potential electrolytes. However, anti-corrosion paints also have a limited lifespan and come with challenges such as high costs, difficult application processes, and environmental concerns. This is particularly true in confined, narrow spaces, where reapplying the coating can be extremely challenging.

According to research by British scientist Vernon, metal corrosion is closely linked to the relative humidity of the surrounding environment—and is independent of temperature. When metal objects are exposed to environments with relative humidity above 60%, the rate of corrosion on their surfaces accelerates dramatically. However, when metals are kept in humidity levels below 50%, the corrosion process on their surfaces remains extremely slow.

This has provided ample room for application of rotor dehumidification, an isenthalpic dehumidification technology. After decades of practical testing, rotor dehumidification technology has been widely adopted and promoted in corrosion protection fields such as steel structures in bridges and power facilities.