Centrifuge is a machine that uses centrifugal force to separate liquid and solid particles or components of a mixture of liquid and liquid, which is a very popular and effective solid-liquid extraction technique. It is widely used in chemical engineering, petroleum, food processing, pharmaceutical, mineral processing, carbon, water treatment, nuclear energy industry and shipbuilding, and other fields. It have two types of centrifuge, including filter centrifuge and decanter centrifuge. The former is to separate solids and liquids substances by centrifugal force generated by the high-speed centrifugal drum (with appropriate filter material), and the latter is to separate substances with different sedimentation coefficient and buoyancy density by strong centrifugal force generated by high-speed rotation of the rotor.
The centrifuge has a cylinder(drum) that rotates at a high speed, which is usually driven by an electric motor. After the suspension (or emulsion) is added to the drum, it is rapidly driven to rotate at the same speed as the drum, and the components within the mixtures are separated under the action of centrifugal force and discharged separately. Generally, the higher the drum speed is , the better the separation will be . When the suspension containing fine particles is left still, the suspended particles gradually sink due to the action of the gravitational field. The heavier the particles are, the faster they sink.