Fire Tube Boiler | Operation and Types of Fire Tube Boiler

Fire tube boiler is one of the most basic types of boiler and the design is also very old. It was popular in 18th century. It was mainly used for steam locomotive engines.

Operation of Fire Tube Boiler

Operation of fire tube boiler is as simple as its construction. In fire tube boiler, the fuel is burnt inside a furnace. The hot gases produced in the furnace then passes through the fire tubes. The fire tubes are immersed in water inside the main vessel of the boiler. As the hot gases are passed through these tubes, the heat energy of the gasses is transferred to the water surrounds them. As a result steam is generated in the water and naturally comes up and is stored upon the water in the same vessel of fire tube boiler.

This steam is then taken out from the steam outlet for utilizing for required purpose. The water is fed into the boiler through the feed water inlet. As the steam and water is stored is the same vessel, it is quite difficult to produce very high pressure steam from. General maximum capacity of this type of boiler is 17.5 kg/cm2 and with a capacity of 9 Metric Ton of steam per hour. In a fire tube boiler, the main boiler vessel is under pressure, so if this vessel is burst there will be a possibility of major accident due to this explosion.

Types of Fire Tube Boiler

According to the location of furnace there are two types of fire tube boiler and these are external furnace and internal furnace type.
There are mainly three types of external furnace fire tube boiler.

1. Horizontal return tubular fire tube boiler.
2. Short fire box fire tube boiler.
3. Compact fire tube boiler.

There are also two types of internal furnace fire tube boiler

1. Horizontal tubular.
2. Vertical tubular fire tube boiler.

Working Principle of Horizontal Return Fire Tube Boiler