In a water tube boiler, where does the heat and gases of combustion pass?

In a water tube boiler, the heat and gases of combustion pass around the tubes. This design allows for more efficient heat transfer since water is contained within the tubes, while the hot gases flow around them, transferring their heat to the water inside. This mechanism enhances the boiler’s efficiency and provides effective steam generation because the surface area for heat exchange is maximized.

The arrangement also allows for a safer operation since water acts as a barrier, reducing the risk of overheating. This is particularly advantageous in high-pressure applications, as the water tube configuration can handle such stresses better than other designs. The design contrasts with fire tube boilers where combustion gases pass through the tubes themselves, which could lead to different thermal dynamics and limitations in pressure handling.