Deaerator

      A deaerator is a device that is widely used for the removal of air and other dissolved gases from the feed water to the steam-generating boilers. In particular , dissolved Oxygen in boiler feed waters will cause serious corrosion damage in steam systems by attaching to the walls of metal piping and other metallic equipment and forming oxides (rust). Water also combines with any dissolved Carbon dioxide to form carbonic acid that causes further corrosion. Most deaerators are designed to remove oxygen down to levels of 7ppb by weight (0.005cm³/L) or less.
            There are two basic type of deaerators . the tray-type and the spray-type.

    * The tray-type (also called the cascade-type) includes avertical domed deaeration
       section mounted on top of a horizontal cylindrical vessel which serves as the deaerated
       boiler feedwater storage tank.

    * The spray-type consists only of a horizontal (or vertical) cylindrical vessel which
       serves as both the deaeration section and the boiler feedwater storage tank.