12embo,
As Tycho mentions what controls level in vessel on flake ice machine.
Normally on clean system oil is returned to compressor with oil “skimmer” system.
Oil rich refrigerant taken from top of refrigerant level in surge drum returns through a heat exchanger to boil off refrigerant before returning to compressor.
From the looks of things Ice machine could have been on ammonia with the type of stop valves I see.

No refrigeration screw compressors run discharge temperature you are referring to, way to hot as we have all mentioned.
Oil would be so thin at those temperatures it probably be vapour or mist.
Please send more photos of how level is controlled in evaporator.