🔍 Key Concepts

• Centrifugal purification of diesel fuel and how density difference affects separation • What types of contaminants are normally removed by purifiers/clarifiers in fuel treatment plants • The relative specific gravity (density) of diesel fuel vs. common contaminants

💭 Think About

• Think about which substance, when mixed with diesel, would form a separate, heavier phase that can be thrown outward in a centrifuge bowl. • Ask yourself: which listed substance is normally expected as a contaminant in diesel fuel treatment systems on ships? • Consider which option is miscible (readily mixes and stays mixed) with diesel and which forms solids or a distinct layer.

✅ Before You Answer

• Verify which of the options is typically removed in fuel oil purifiers or fuel centrifuges on board ships. • Check which substances have a different density from diesel that allows separation by centrifugal force. • Eliminate choices that would readily mix with diesel and not form a separable layer under centrifuging.