Analysis of the cause of heat exchanger leakage in the ammonia nitrate oxidation furnace
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It is understood that heat exchangers in the ammonia oxidation furnaces of many nitric acid plants have experienced leaks. So, let’s discuss: what are the causes of leaks in the heat exchangers inside the ammonium nitrate oxidation furnace?
1. Poor boiler operation leading to a water shortage can cause pipe explosions； 2. Poor operation of the deaerator, resulting in high dissolved oxygen levels in the water, can cause oxygen corrosion in the boiler coils ； 3. The dosing of chemicals into the steam drum not only leads to excessive levels of phosphates in the water, but it also causes corrosion of the boiler coils ； If the phosphate level in water remains low for an extended period, it can cause scaling on the boiler coils, leading to localized overheating and damage to the coils ； 4. A superheated steam temperature above 450°C can cause corrosion of the steam in the coils, leading to damage to the tubes. 5. High chloride levels in the boiler feed water can cause chlorine corrosion of the coils ； 6. If the pH of the boiler water is below 7, it can cause acidic corrosion of the coil ；
The explanation upstairs is quite comprehensive. One more thing: Is the preheating during the steam superheating stage while driving sufficient?