Low Temperature Corrosion in Boiler and Its Prevention

Fuels used in boilers contain different levels of sulphur which is the primary cause for cold end corrosion. The severity depends on many factors like percentage of sulphur in fuel, excess air, moisture in flue gas etc. There are many methods used world over to contain cold end corrosion. These methods fall in the category of in combustion reduction and post combustion reduction. In-combustion reduction methods include burning low sulphur fuel, low excess air burners, fuel additives and fluidized bed combustors. The post-combustion technologies adopted are designing with higher exit gas temperature, air bypass across air pre-heater, ammonia injection, flue gas desulphurization (FGD).