why is feedwater temperature important - oxygen content.
The oxygen content of steam boiler feedwater is crucial because dissolved oxygen can cause corrosion of the boiler and its components. Heating the feedwater to a high enough temperature reduces the amount of dissolved oxygen, minimising the risk of corrosion and extending the boiler’s lifespan.
Dissolved Oxygen and Corrosion:
Water naturally contains dissolved oxygen. When this water is heated in a boiler, the oxygen can react with the metal components, leading to rust, scale, and eventual corrosion.
Temperature and Oxygen Solubility:
The solubility of oxygen in water decreases as the temperature increases. By heating the feedwater, you encourage the dissolved oxygen to leave the water and vent out of the system, reducing the amount of oxygen available to cause corrosion.
Minimising Chemical Treatment:
A high feedwater temperature can significantly reduce the amount of chemical oxygen scavengers needed to remove remaining dissolved oxygen.
Ideal Temperature:
While the ideal feedwater temperature for a boiler can vary, a common recommendation is to maintain it at a minimum of 80°C. Temperatures above this can improve efficiency, but exceeding a certain point can cause issues with feed pumps.
Deaeration:
Heating the feedwater is a form of deaeration, which is the process of removing dissolved gases from the water. Further chemical treatments may be needed to remove any remaining oxygen
