Air acts as an oxidizing agent and causes corrosion and weakening leading to damage and leakage in pipes and related equipment. In Boilers it can cause serious accidents.
Air gets in the system mainly through Boiler Feed water. The harmful element in Air is Oxygen, and De Aeration essentially involves removal of Oxygen. This is done by heating the water in the De-aerator Head (DAH) to 90Deg C when Bulk of the Oxygen is eliminated. [Ideally at 102-105Deg C, Oxygen is almost totally eliminated] when the bulk of Oxygen is released from the Hot water.
De-Aerator is a dome shaped device [called the mixing unit] fitted to the Feed Water Tank, having three Nozzles for Cold Make up Water, Recovered and recycled hot condensate and Flash Steam. It also has a top vent nozzle with automatic thermostatic vent. The three nozzles result in mixing of the three fluids, consequently heating the water and the Oxygen thus released is vented out from the top. A SS dip/Immersion tube with perforations attached to the De Aerator is led into the tank up to near to the tank bottom, releasing hot water through perforation from the bottom level of water helps the mixing of the heated water from the De Aerator Head and the water available in Feed water Tank, and supply hot water to boiler, saving Fuel costs, reducing O2 and avoiding Flashing and noise, and achieve higher levels of process efficiency.