Definition - What does Deaerator mean?
Deaerator is a device which is used to remove oxygen and various other dissolved gases from feedwater to boilers which generate steam. Particularly, the dissolved oxygen present in the boiler feedwater causes corrosion damage to the steam systems. Carbonic acid is formed when dissolved CO2 combines with water which causes further corrosion. These devices are designed for reducing the oxygen level down to the 7ppb by weight or less, and eliminating carbon dioxide as well.
Petropedia explains Deaerator
Deaerators are used to protect steam systems from the harmful effects of corrosive gases. They accomplish this by lowering the concentrations of dissolved carbon dioxide and oxygen to a level at which corrosion is minimized. The design of an effective system is based on the amount of gases that are to be removed and final desired concentration of oxygen gas. They use steam for heating water to full saturation temperature to correspond to the steam pressure in the Deaerator and carrying away the dissolved gases. The flow of steam can be parallel, counter or cross to water flow.