Fire tube boilers are one of the most basic yet widely used steam boilers in a wide variety of industrial processes. They come set up with pumps and control systems that make them ready to install and start operations easily once connected to a fuel and water supply. These boilers are ideal for low to medium pressure steam requirements and are utilized by mostly small and medium-sized industries.
In a fire tube steam boiler, the fuel undergoes combustion in a furnace, and the hot gases produced pass through the fire tubes that are immersed in water inside the main vessel. As the hot gases pass through the tubes the heat energy gets transferred to the water, generating steam. This steam gets extracted from the boiler and is utilized for various processes. As the steam and water are both stored in the same vessel, the steam produced is at very low pressure. In fire tube boilers the main vessel is under immense pressure which can lead to explosion and cause severe damage.
Types of Firetube Boilers
Based on where the main furnace is located, fire tube steam boilers can be categorized as external and internal furnace-type boilers. The external furnace boilers come in three types:
- Horizontal return tubular boiler
- Short firebox fire tube boiler
- Compact fire tube boiler
Internal Furnace Boilers are of Two Types:
- Horizontal tubular
- Vertical tubular fire tube boiler
Advantages of Fire Tube Steam Boilers
- Compact design uses up little floor space, making the operations in the boiler room easier to perform
- Fluctuations of steam demand can be met easily
- Cheaper than other types of industrial boilers like water tube boilers, which make them a more viable option for small industries with limited requirements of steam
Disadvantages of Fire Tube Steam Boilers
- The time required for the pressure to rise in the water vessel to the desired levels is quite high
- The output steam pressure is not very high and can not be used for a lot of industrial processes like running turbines
- The steam produced by fire tube boilers is not dry
- The steam drum in fire tube boilers is usually under a lot of pressure that poses the threat of explosion