Where is water found in a fire tube boiler?

In a fire tube boiler, water is found around the tubes. This design involves hot gases from combustion passing through tubes that are submerged in a water-filled shell. The heat from the gases is transferred through the tubes, warming the surrounding water, which then turns into steam. This configuration allows for efficient heat exchange and is beneficial for the boiler’s operation, as it enables the generation of steam while ensuring that the hot combustion gases do not directly mix with water.

In this type of boiler, placing water around the tubes maximizes the surface area for heat transfer, which is critical for effective steam production. The other choices, such as water being inside the tubes, in a separate storage tank, or at the bottom of the combustion chamber, do not reflect the functional layout of a fire tube boiler, which is specifically designed as described.