What is the purpose of deaerator in feed water treatment.

The primary purpose of a deaerator in feedwater treatment is to remove dissolved gases, primarily oxygen and carbon dioxide, from the boiler feedwater. Dissolved oxygen is highly corrosive to boiler tubes and other metallic components in the steam cycle. Oxygen corrosion can lead to pitting, thinning, and eventual failure of boiler tubes, resulting in costly repairs and downtime. Carbon dioxide, when dissolved in water, forms carbonic acid, which also contributes to corrosion. The deaerator operates by heating the feedwater and reducing its pressure, which decreases the solubility of gases in water. The feedwater is typically sprayed into a vessel filled with steam, which further heats the water and strips out the dissolved gases. These gases are then vented to the atmosphere. Deaerators typically reduce dissolved oxygen levels to below 7 parts per billion (ppb) and dissolved carbon dioxide levels to very low concentrations, significantly reducing the risk of corrosion in the steam cycle.