The function of the Boiler Economizer
The Economizer in Boiler works on the principle of Heat Transfer. Heat transfer usually takes place from high temperature to low temperature.
In the case of Boilers, flue gases or exhaust from the boiler outlet are at high temperature and water that needs to be preheated is at low temperature.
So, this temperature difference between water and flue gases helps to increase the feed water temperature.
Depending on the type of operations, the design of Economisers can be smoke tube type or water tube type.
In the smoke tube type, flue gases are inside the tubes and water is on the shell side while in the water tube type, water is in the tube and flue gases are on the shell side.