Deoxygenator
I. Applications and Advantages of Film-Type Deaerators
Film-type deaerators heat boiler feedwater to the saturation temperature corresponding to the operating pressure of the deaerator, removing oxygen and other gases dissolved in the feedwater to prevent and reduce corrosion of boiler feedwater pipes, economizers, and other auxiliary equipment.
Hundreds of power plants have proven the following advantages of film-type deaerators in operation:
1. High deoxygenation efficiency, 100% qualified feedwater. (High pressure 5цɡ/L, low pressure 10цɡ/L)
2. Stable operation, no vibration. When the load changes by 25%, the water supply changes by 10%, and the water temperature drops, the deaerator remains vibration-free and without vaporization.
3. Good adaptability. In addition to its advantages such as being undemanding of water quality and temperature, it can also operate at an overload of about 50%, especially for heating units and deaerators with sliding pressure operation, which shows its superior performance.
4. The exhaust steam volume is less than 0.1% of the inlet water volume, and no additional exhaust gas cooler is required. It consumes 1/3 less energy than other types of thermal deaerators with the same output, optimizing equipment and reducing heat consumption.
II. The Role of Film-Type Deaerators in Boiler Water
In the boiler feedwater treatment process, boiler water deoxygenation is a crucial step. Oxygen is the main corrosive substance in the feedwater system and boiler. The oxygen in the feedwater should be removed quickly; otherwise, it will corrode the boiler feedwater system and components. The corrosion product, iron oxide, will enter the boiler, depositing or adhering to the boiler tube walls and heating surfaces, forming iron scale with poor heat transfer. Moreover, corrosion can cause pitting on the inner walls of the pipes, increasing the resistance coefficient. In severe cases of pipe corrosion, pipe explosions may even occur. Domestic regulations stipulate that steam boilers with an evaporation capacity greater than or equal to 2 tons per hour and hot water boilers with a water temperature greater than or equal to 95℃ must be deoxygenated.
