What is the main function of a fire tube boiler?

The main function of a fire tube boiler is to generate steam by passing hot gases through tubes. In this design, the combustion gases travel through tubes that are surrounded by water. As the hot gases move through the tubes, they transfer heat to the water, causing it to boil and convert into steam. This process is efficient for steam generation, making fire tube boilers commonly used in various industrial applications.

Fire tube boilers operate on the principle of heat transfer, utilizing the high temperature of the combustion gases to effectively raise water temperature and produce steam. Several factors contribute to their popularity, including their relatively simple design, lower initial cost compared to other types of boilers, and ease of maintenance. They are particularly effective in applications where steam demand is moderate and the operating pressure is lower.

In contrast, the other functions outlined in the options do not align with the primary purpose of a fire tube boiler. Cooling water pertains to processes that involve extracting heat rather than generating steam. Transporting steam refers to the distribution aspect rather than steam generation itself. Lastly, purifying fuel is unrelated to boiler operation, as it pertains to preparing fuel before combustion takes place.