What is a Deaerator?

What is aDeaerator?

Deaerator is a device that is widely used to remove air and other dissolved gases from boiler feed water to generate steam. In particular, dissolved oxygen in boiler feedwaters will cause serious corrosion damage in steam system by attaching to the wall metal pipe and other metal equipment and forming oxides (rust). Water also combines with carbon dioxide dissolves to form carbonic acid that causes further corrosion. Deaerators Most are designed to remove oxygen to a severe level of 7 ppb (0.005 cm ³ / L) or less.

There are two basic types of deaerators, tray-type and spray-type.

1. Tray type (also called a cascade-type) including vertical domed deaeration section mounted on a horizontal cylindrical vessel which serves as a storage tank deaerated boiler feed water.
2. Spray-type consists only of a ship (or vertical) horizontal cylinder which serves both as the boiler feed water deaeration and storage tanks.

Deaerator consists of two small drums where the drum is prelimenery heating and exhaust gases from the feedwater, while the larger drum is a shelter to feed water that falls from a smaller drum on it. In the spray nozzle containing a smaller drum that serves to spray water feed into fine droplets of water so that the process of heating and exhaust gases from the feedwater can be done perfectly.

Check out our other guide on:

• What is Air Preheater?

What is an Air Preheater?

air preheater

An air preheater (APH) is a general term to describe any device designed to heat air before another process (eg, combustion in the boiler) with the main objective improving the thermal efficiency of the process. Air Pre Heaters can increase boiler efficiency and decrease chimney loss. They can be used alone or to replace a heat recovery system or to replace the steam coil. An air preheater (APH) is a device used in steam boilers to transfer heat from the flue gases to the combustion air before it enters the furnace. Air Preheater recovers the heat from the boiler flue gas and increases the thermal efficiency of the boiler . The Flue gases are sent to the fuel gas stack at a lower temperature It allows control over the temperature of gases.

The combustion air preheaters are used in large boilers are found in thermal power plants generate electricity from such fossil fuels, biomass or waste.

The purpose of the air preheater to recover heat from boiler flue gases that increase the boiler thermal efficiency by reducing the useful heat lost in flue gases. As a result, the flue gas is also sent to the stack flue gas (or chimney) at lower temperatures, allowing simplified design of ducting and exhaust stacks. It also allows control over the temperature of the gas leaves the stack (to meet emissions regulations, for example).

air preheater schematic diagram
tubular type