Fire tube boiler
Fire tube boilers are designed to transfer hot gases from the heating source and cycle these gases through tubes that circulate through a drum filled with water. This process effectively transfers the heat from the gas into the water, which effectively generates steam.
Due to this relatively simple design, fire tube boilers are easy to operate and inexpensive to purchase. With the ability to generate medium to low degrees of pressure, fire tube are exceptionally versatile and able to be configured in a variety of designs. The following information explains some of the most common designs for fire tube boilers.
1. Horizontal Return Tubular Fire Tube Boiler
As one of the oldest and most simple designs forindustrial boilers, the Horizontal Return Tubular fire tube boilers are still being produced today. It features a shell, a tube sheet on each end of the shell, and tubes that connect both tube sheets.
The boiler is mounted above the masonry or steel furnace. Once the combustion products leave the furnace, it's directed through the tubes on the end of the boiler. After going through the tubes, the combustion products leave the other end of the boiler. The combustion products are directed to the chimney or stack.
2. Firebox Boiler Design
The firebox boiler design utilizes locomotive boilers and fire tube firebox boilers. As a one-pass boiler design, the combustion products pass through the locomotive boiler once. Depending on the arrangement of the tubes and baffles, some firebox boiler designs may be a three-pass or two-pass.
The most common characteristic of the firebox boiler design is a furnace that may be contained partially in the boiler. The furnace is cooled by water for the majority of its entire surface area.
Multi-pass boilers are an extremely common option. These boilers are typically found in colleges, universities, or areas where the system is used to produce steam forspace heatingor use to create hot water.