MDE 11 Q7

• Correct Answer: B) A rotating bowl or rotor

Explanation: The rotating bowl or rotor is the key component that creates the centrifugal force needed to separate contaminants from the oil. As the rotor spins at high speed, the centrifugal force causes the heavier contaminants to move outward and accumulate on the inner wall of the bowl, while the cleaner oil remains closer to the center and is then recirculated.

Correct Answer: B) To separate water from fuel by causing small water droplets to combine into larger droplets.

Explanation:
The primary function of a coalescer type filter is to separate water from fuel. It works by causing small water droplets dispersed in the fuel to coalesce (combine) into larger droplets, which can then be easily separated from the fuel. This is essential in preventing water contamination in the fuel, which can cause corrosion and other operational issues in a diesel engine.

Correct Answer: B) Viscometer test
Explanation: A viscometer test is used to measure the oil's viscosity, which is crucial for ensuring proper lubrication and engine performance.

These questions cover various aspects of assessing the condition of lubricating oil in a large medium-speed diesel engine on board a vessel.

Correct Answer: B) Because high temperatures can cause oil degradation and carryover

Explanation: High temperatures can lead to oil degradation, which affects the separator’s ability to effectively separate contaminants, resulting in oil carryover and loss.

Correct Answer:
C) The filter uses centrifugal force to separate contaminants from the oil.

Explanation: A centrifugal lubricating oil filter operates by spinning the oil at high speeds, which generates centrifugal force. This force pushes heavier contaminants, such as dirt, metal particles, and sludge, to the outer edges of the filter, effectively separating them from the cleaner oil. The clean oil can then be recirculated back into the engine, while the contaminants remain trapped in the filter.

Correct Answer: C) Incomplete separation of contaminants

Explanation: Incomplete separation can lead to oil carryover, where the oil mixed with contaminants exits the separator, causing oil losses.

Correct Answer: B) It is capable of removing both solid and water contaminants simultaneously.

Explanation:
A coalescer filter is designed to remove water from fuel, but many coalescer systems are also equipped with pre-filters that can remove solid contaminants as well. This dual-functionality makes them particularly useful in ensuring the cleanliness and quality of the fuel before it is used in the engine.

Correct Answer: D) The oil’s contamination level

Explanation: The contamination level of the oil directly affects how often the purifier needs to discharge. High contamination levels will require more frequent discharges to ensure the oil remains clean.