Oil Mills in Continuous Cycle. Cold extraction with only mechanical methods.Modern oil mills use this type of technology that does not require interruptions in the olive processing cycle.
The name of the Continuous Cycle method derives from the fact that it consists of a set of machines connected with each other and which exclude any interruption in processing the olives.
The four connected parts are
- the crusher
- the kneader
- the separator
The crusher mashes the olives into a paste or dough with a preliminary, partial extraction of oil. The paste and the first oil pass on to the kneader which has the purpose of recovering the oil still trapped in the paste.
The kneader is a long, narrow basin fitted with a continuously rotating central axis with mixing blades. The movement of the blades ruptures the tiny sacks in the olive paste that hold more oil. The kneader, with a water circulation system similar to a radiator, is kept at a constant temperature.
The kneaded dough, diluted with water, passes into an extractive centrifuge called the decanter. This centrifuge, because of the weight of the different elements, discards the husks and the final separator sends off in different directions the water released into the decanter, the water contained originally in the olives, and the oil.
In the “continuous cycle” method the extraction is thus entrusted to the decanter, a centrifuge with a horizontal drum. The resulting oil is referred to as “cold extracted” if a temperature of 27°C (80°F) has not been exceeded during grinding and extraction.