MDE 11 End of Unit Quiz

Correct Answer: B) The level of contaminants in the oil

Explanation: The discharge frequency of the oil purifier is largely determined by the amount of contaminants in the oil. Higher contamination levels lead to more frequent discharges to maintain oil purity.

Correct Answer: A) A larger capacity purifier will have a lower discharge frequency

Explanation: A purifier with a larger capacity can handle more oil before needing to discharge contaminants, thus reducing the frequency of discharges.

Correct Answer: B) Periodically cleaning the oil using a centrifugal separator
Explanation: Regular cleaning of the lubricating oil using a centrifugal separator removes contaminants and helps maintain the oil in optimum condition. While changing the oil is important, it’s not as frequent and essential as cleaning.

Correct Answer:
B) The filter uses a series of closely spaced metal plates to trap and remove solid particles from the oil as it passes through.

Explanation: A plate edge (e.g., Auto-Klean) lubricating oil filter works by passing the oil through a series of closely spaced metal plates. As the oil flows between the edges of these plates, solid particles are trapped and removed from the oil, effectively filtering it. This type of filter is often self-cleaning, as the plates can be scraped clean without needing to stop the system.

• Correct Answer: C) Oil is spun at high speed to separate contaminants based on density

Explanation: The centrifugal filter operates by spinning the oil at high speed within the rotor. This high-speed rotation creates a centrifugal force that causes the denser particles (contaminants) to move outward, separating them from the less dense, cleaner oil. This process is entirely mechanical and relies on the principle of density differences.

• Correct Answer: C) To remove contaminants from the oil by using centrifugal force

Explanation: The primary function of a centrifugal type lubricating oil filter is to remove contaminants such as dirt, metal particles, and other impurities from the lubricating oil. It does this by spinning the oil at high speeds in a rotating bowl or rotor, which generates centrifugal force. This force pushes the denser contaminants to the outer wall of the rotor, separating them from the cleaner oil.

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) Inadequate maintenance of the separator

Explanation: Poor maintenance can affect the separator’s ability to properly separate contaminants, leading to oil carryover and subsequent oil loss.

Correct Answer: A) By preventing oil leakage through seal and joint failures

Explanation: Proper sealing and joint integrity prevent oil from leaking out of the separator, thus minimizing oil losses.

Correct Answer: C) A damaged water pump

Explanation: A damaged water pump can lead to coolant leakage, which may then mix with the engine oil and cause water contamination.

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.

Correct Answer:
B) The filter employs a magnetic field to attract and remove ferrous particles from the oil.

Explanation: A magnetic lubricating oil filter operates by using a magnetic field to attract and capture ferrous (iron-based) particles that may be present in the oil, thereby preventing these particles from circulating through the engine and causing wear or damage.