A boiler recovers heat from burned fuels. This is accomplished when high pressure boiler feedwater inside tubes located throughout the boiler is heated and turns into steam or hot water. The steam or hot water is then used in a variety of facility processes. Boiler feedwater often contains dissolved oxygen, which is a common cause of corrosion inside boilers. The dissolved oxygen reacts with the boiler's waterside metal surfaces to damage boiler tubes, headers, and drums. Corrosion can become more aggressive depending on the concentration of gas, pH, and temperature of the boiler feedwater. Therefore, the purpose of deaeration is to remove dissolved oxygen, carbon dioxide, and other non-condensable gases from boiler feedwater.
•Identify and describe the safety hazards and safe work practices associated with boiler feedwater deaeration
•Explain the purpose of deaeration
•Explain how the amount of dissolved gases in water can be reduced
•Describe the function of tray-type and spray-type deaerators
•Identify and describe the key equipment and process flows associated with feedwater deaeration
•Describe the purpose of oxygen scavengers
