🔍 Key Concepts

• How airborne contaminants enter and move through an axial or centrifugal compressor • Difference between what is carried in the intake air stream versus what is created in the combustion section • Typical causes of compressor fouling in marine gas turbines or large air compressors

💭 Think About

• Which of these substances would realistically be present in the airflow entering the compressor on a routine basis? • Which options include something that is more likely to be a by‑product of combustion rather than a contaminant in the intake air? • Think about what would tend to form a sticky coating that traps other particles on the blades.

✅ Before You Answer

• Make sure both chosen sources can reach the compressor blades through the intake, not from downstream parts like the combustor or exhaust • Confirm that each source is something that would gradually build up over long running periods, not just appear briefly • Eliminate any source that is mainly associated with burned fuel residues rather than with the incoming air or nearby machinery leaks