A deaerator is a device that removes oxygen and other dissolved gases from liquids and pumpable compounds. History Before 1881, feed water heaters were used for marine applications. Two sister ships Olympic and Titanic (1912) had contact feed heaters on board. In 1934 the US Navy purchased an atomizing deaerator. Before 1867, deaerators were used as part of the ice manufacturing purification process. In 1899, George M Kleucker received a patent for an improved method of deaerating water. During the 1920 the feedwater headers and deaerators designs improved. Stickle, Cochrane, and Permutit are three of the oldest Deaerator manufacturers in the USA. In 1929, a court case between Elliott Company (no longer in business) and H.S.B.W. Cochrane Corporation allowed both business to continue manufacturing deaerators. Deaerators continue to be used today for many applications. Types The thermal deaerators The spray & tray-type (also called the cascade-type) includes a vertical or horizontal 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 a storage tank for boiler feedwater. The vacuum deaerators Dynamic deaerator for medium to high viscous products Static deaerator for low viscous products The ultrasound deaerator for very viscous products Thermal deaerators Thermal deaerators are commonly used to remove dissolved gases in feedwater for steam-generating boilers. Dissolved oxygen in feedwater will cause serious corrosion damage in a boiler by attaching to the walls of metal piping and other equipment and forming oxides (like rust). Dissolved carbon dioxide combines with water to form carbonic acid that may cause further corrosion. Most deaerators are designed to remove oxygen down to levels of 7 ppb by weight or less, as well as essentially eliminating carbon dioxide. The deaerators in the steam generating systems of most thermal power plants use low pressure steam obtained from an extraction point in their steam turbine system. However, the steam generators in many large industrial facilities such as petroleum refineries may use whatever low-pressure steam is available. There are many different deaerators available from a number of manufacturers, and the actual construction details will vary from one manufacturer to another. Figures 1 and 2 are representative schematic diagrams that depict each of the two major types of deaerators. Spray and tray-type deaerator The typical spray & tray-type deaerator