The occurrence of dew point corrosion
Thread Content
Could you please provide details on conditions such as the temperature at which dew point corrosion occurs? The more specific, the better
Flue gas dew point corrosion occurs because sulfur in the fuel is converted into SO2 and SO3 during combustion; when the outer surface temperature of the heat exchange surface is lower than the temperature of the flue gas, sulfuric acid mist droplets form on that surface, leading to corrosion of the heat exchange surface. As for the temperature conditions, they should be determined based on the actual conditions of the facility. In our plant, the raw material is mainly Harbin Oil, and the outlet temperature requirement for the air preheater in the flue gas waste heat recovery system is between 155 and 177 degrees Celsius ； In the waste heat boiler system, the outlet temperature of the deoxygenated water tank is required to be above 90 degrees, as this helps to prevent dew point corrosion ； In my opinion, it has a lot to do with the water content and sulfur content in it ； In short, it is sufficient to ensure that the temperature of the metal is higher than the dew point temperature of the flue gas ；