Question 31 MODE01 - Chief MODU Engineer

The Correct Answer is C **Explanation for Option C (Shunt System):** The shunt filtration system (often referred to as a partial flow system in the context of modern engine design, though "shunt" is a historically precise term) is the correct answer because it is specifically designed to filter a portion of the oil *before* it enters the main engine lubrication circuit. In a full-flow system, all oil goes through the filter before the engine. In a shunt system, the filter is placed in a way that it routes cleaned oil directly into the high-pressure supply gallery or main oil rail, ensuring that the oil supplied to the critical engine components is filtered immediately prior to delivery. This system maintains a high rate of oil flow to the engine while still providing continuous filtration. **Explanation for Incorrect Options:** * **A) centrifugal purifier system:** A centrifugal purifier uses rotational force to separate contaminants based on density, primarily water and very fine solids. While highly effective, it typically operates off-line or filters oil very slowly (not directly feeding the high-pressure gallery) and is often used in conjunction with full-flow or bypass filters, but it is not the primary filtration system routing oil directly to the supply gallery. * **B) batch system:** A batch filtration system requires the engine to be stopped and the oil drained into an external unit for cleaning. It does not provide continuous filtration and certainly does not send filtered oil directly to the high-pressure supply gallery during engine operation. * **D) bypass system:** In a bypass system (or kidney loop system), a small amount of oil (typically 5–10%) is continuously diverted from the main lubrication system, filtered very finely (often sub-micron), and then returned to the oil sump (oil pan). It cleans the bulk oil over time but does not send the cleaned oil directly and immediately to the high-pressure supply gallery; it returns the oil to the low-pressure side of the circuit (the sump).