Rotating machines that artificially accelerate the gravity field through high-speed rotation — typically 3,000 to 10,000 g. They differ from Cyclones precisely because they have moving parts: where the cyclone uses only the flow, the centrifuge uses a rotor.
Usual types
- Decanter (horizontal decanter centrifuge) — horizontal cylinder with an internal screw that dewaters solids continuously; standard for sewage sludge, crude oil, mining.
- Disc-stack — a stack of conical discs that amplify the gravity-separation area; liquid-liquid separation in oils, dairy, biodiesel.
- Basket — batch; crystals, coarse solids.
Reliability: main bearings at high speed, imbalance from uneven wear of internal parts, erosion from processed solids, structural integrity of the bowl. Vibration as the primary diagnostic Fw (long P-F). API 613 governs centrifuges in severe process service.