What is Boiler? – A Simply Explanation

What is Boiler?

Boiler or also known as Steam Generator is a closed vessel in which contains water to be heated. The thermal energy of the boiler’s water vapor is then used for various purposes, such as for steam turbines, room heaters, steam engines, and so on. In the term of energy conversion process, the boiler has a function to convert chemical energy stored in the fuel into heat energy transferred to the working fluid.

Pressurized boilers generally use steel materials with certain specifications that have been specified in the ASME standard, primarily for the use of boilers in large industries. In recorded history various types of materials are used as boiler materials such as copper, brass, and cast iron. However, these materials have long been abandoned for economic reasons as well as material resilience that is not in accordance with industry needs.

The heat given to the fluid in the boiler comes from the combustion process with various types of fuel that such as wood, coal, diesel, petroleum, and gas. With the advancement of technology, nuclear is also used as a source of heat in the boiler.

Here are some examples of types of boilers:

1. “Boiler Pot” or “Haycock Boiler”

It is the simplest boiler in history. It began to be introduced in the 18th century, using large water volumes but can only produce at low pressure. This boiler uses wood or coal as its fuel. This type of boiler does not last long because its efficiency is very low.

2. Fire-Tube Boiler

In subsequent developments comes the design of fire-tube boiler. This boiler has 2 main parts in it, the tube/pipe side and the barrel side. The barrel side contains water, while the pipe side is the place of burning.

what is boiler
Fire-tube Boiler

Fire-tube boilers usually have a low vapor production speed, but have a larger reservoir of water vapor.

3. Water-Tube Boiler

Just like a fire-tube boiler, a water-tube boiler also consists of two main parts which is pipes and barrels. But the side of the pipe is filled with water while the barrel side becomes the place of the burning process. This type of boiler has a high velocity in producing water vapor, but does not have much water vapor reserves in it.

Water-tube Boiler

4. Combination of Fire-tube with Water-tube Boiler

This type of boiler is a combination of a fire-tube boiler with a water-tube. A firebox in it contains pipes filled with water, the resulting water vapor flows into the barrel with a fire-pipe inside. This type of boiler is used to be the locomotive engine, but not very popular in history.