With a 3 phase decanter centrifuge, it is possible to separate 3 phases from each other in one process step only. For example, two liquids which cannot be mixed because of different densities (e.g. oil and water) are separated from a solids phase. The heavy liquid (water) collects in the middle between the oil and the solids layer. Thus the two liquids separated from each other can be drawn off from the decanter. The solids are transported via the scroll to the discharge openings as it happens also in 2-phase separation. Typical applications of 3-phase separation are the production of edible oils such as olive oil, oil sludge processing, the production of biodiesel .