18:39 Dec 15, 2011 

I believe "decant" only refers to the pouring of the upper liquid (typically a hydrocarbon based liquid) and not the whole process of separation. Before decanting, separation may occur by different techniques: gravimetric (most typical), using 'clarifiers' (in the lab we call this sequestration - it is a chemical process), physical separation (the technique which is described by the asker is physical), demulsification (can be a physical or chemical process), coagulation, etc.
Industrial chemistry oftens uses terms which are different from lab. research chemistry (in industrial non-systematic names are much more common for example) so maybe the machine is a clarifier but I'm not sure that clarification is the process described by the asker.
However Gracie seems to give a good definition of the machine in English, which is separating PARTICLES not oil from water.....