In an Ammonia flooded evaporator, why could oil gather at the lowest point?

The correct rationale for why oil could gather at the lowest point in an ammonia flooded evaporator is that oil is heavier and has a higher boiling point than ammonia. This characteristic of oil causes it to settle at the lowest point in the system when there is a mixture of both substances.

In a flooded evaporator, ammonia is used as a refrigerant and typically exists in liquid form, while the oil, which is used for lubrication of the compressor, tends to separate due to its density. Since oil does not vaporize as readily as ammonia due to its higher boiling point, it remains in liquid form and accumulates at the lowest point of the system. This accumulation can lead to potential issues like reduced efficiency or even damage if not properly managed.

Understanding the behavior of oil in relation to its physical properties compared to ammonia is critical for maintaining effective operation of the refrigeration system, ensuring that the oil does not interfere with the heat exchange process or the overall operational efficiency.