Boiler Feed Water Treatment Deaeration Process:-
The process through which the dissolved gases are removed from water is called the “Deaeration Process”. The equipment, which is used in this method, is called “Deaerator“.
# Why do we use deaerators?
The Deaerator (DA) tank uses steam to preheat boiler feedwater to a temp. at which dissolved O2 & CO2 will become separated from the feedwater before it is pumped to the boiler. The purpose is to protect the boiler and steam/condensate piping from corrosion that would be present when the water evaporates into steam. An additional benefit is that the number of chemicals used to treat the boiler water can be reduced.
# Dissolved CO2 combines with water to form carbonic acid that causes further corrosion.
# Working Principle of Deaerator:-
1️⃣ By Henry’s Law- According to William Henry state that gas solubility in a solution decreases as the gas partial pressure above the solution decreases. In simple, we can say that The solubility of any gas dissolved in a liquid is directly proportional to the partial pressure of the gas. The solubility of gases decreases with an increase in solution temperature and or decrease in pressure.
2️⃣ The second principle state that deaeration is the relationship between gas solubility and temperature. Easily explained, gas solubility in a solution decreases as the temp. of the solution rises and approaches saturation temperature.
# Main Types of Deaerators:-
=> Tray type Deaerator.
=> Spray type Deaerator.
=> Pressurized type Deaerator.