Engineering · Auxiliary — Distillers
A low-pressure (vacuum) evaporator makes fresh water from seawater by:
- AFiltering the salt out mechanically
- BBoiling seawater at a reduced pressure and low temperature, then condensing the vapor✓ Correct
- CFreezing the seawater
- DAdding chemicals to precipitate the salt
Explanation
Operating under vacuum lowers the boiling point so low-grade heat (e.g., jacket water) can evaporate seawater. The salt-free vapor is condensed to distillate; brine is discharged overboard.
Authority: Auxiliary Machinery (USCG engineering topic)
Practice the full Engineering bank
Free spaced-repetition quizzing across 2190 USCG exam questions — it schedules your reviews so the ones you miss come back until they stick.
Related Engineering questions
- Auxiliary — Distillers
A marine evaporator (distilling plant) produces fresh water from seawater by:
- Auxiliary — Distillers
Distilled water from a low-pressure evaporator should NOT be produced when the ship is operating in:
- Diesel — Operating Cycle
In a four-stroke-cycle diesel engine, the events occur in which order?
- Diesel — Operating Cycle
Compared with a four-stroke engine of the same speed and cylinder size, a two-stroke-cycle diesel produces a power stroke:
- Diesel — Air Systems
The primary purpose of scavenging in a two-stroke diesel engine is to:
- Diesel — Air Systems
A turbocharger increases engine power output mainly by: