🔍 Key Concepts

• Density difference and how a centrifugal purifier separates contaminants based on specific gravity • The relative densities of lube oil, water, fuel, metal particles, and carbon at normal operating temperatures • The effect of particle size and emulsification on what a purifier can and cannot separate

💭 Think About

• Think about which impurity has a density and behavior in oil that is too similar for a centrifugal purifier to separate efficiently at normal temperature. • Ask yourself: which of these contaminants is usually removed by filters or chemical treatment rather than by a centrifugal purifier? • Consider which contaminants form a distinct heavier or lighter phase compared to lube oil, making them easier to throw out with centrifugal force.

✅ Before You Answer

• Verify which impurities are heavier than lube oil and tend to move outward in a centrifuge bowl. • Verify which impurity is miscible with lube oil and may not form a separate layer at normal purifier operating conditions. • Check which contaminants are typically listed in engineering texts as being handled by purifiers vs. by strainers/filters.