What are auxiliary boilers classified as?

Auxiliary boilers are classified as fire or water tube boilers because they use either a fire tube or water tube system to generate steam. In a fire tube boiler, the combustion gases pass through tubes that are surrounded by water. This design allows for efficient heat transfer and steam production. In a water tube boiler, on the other hand, water flows through tubes that are heated externally by combustion gases, allowing for higher pressures and efficiencies.

Auxiliary boilers are typically used in marine applications to provide steam for various functions, such as heating, sterilization, or powering auxiliary machinery. Given the context of auxiliary boilers, categorizing them as fire or water tube boilers showcases their operational mechanisms and construction types.

In contrast, other classifications like single-pass boilers, condensing boilers, or electric boilers do not capture the primary characteristics of auxiliary boilers. Single-pass refers to a specific flow arrangement that may or may not apply. Condensing boilers are designed to recover heat from exhaust gases, which is not characteristic of most auxiliary boilers. Electric boilers, while a valid technology, operate differently and are not typically used as auxiliary steam sources on ships where fuel combustion is the norm.