Exam Question

### (a) Composite Boiler: Definition, Sketch, and Parts
**Concept and Definition**
A composite boiler is a dual-purpose pressure vessel designed for marine applications that combines the functions of an oil-fired auxiliary boiler and an exhaust gas economizer into a single shell. This design allows for steam generation using two independent heat sources: the combustion of fuel oil in a dedicated furnace section, and the waste heat from the main engine's exhaust gases passing over a separate tube bank.
This configuration is particularly advantageous on vessels where engine room space is a premium, as it consolidates two pieces of equipment into one, saving space, reducing weight, and simplifying installation.