The word "Centrifuge", as explained in the dictionary, is a rotary machine, with accessory containers, tubes, etc., for the separation by controlled centrifugal force of substances having different densities. "Centrifugal force" is the inertial reaction of a body against a force constraining it to move in a curved path.

Centrifuges were invented in the 1800's as a hand-cranked device originally used in the farming industry to separate cream from milk. As time passed and technology advanced centrifuges were improved and are now specifically designed for applications in various industries.

Today, a common centrifuge rotates at approximately 5000 to 7000 rpm with some rotating at speeds of up to 50,000 rpm. The centrifuge employs the marvel of centrifugal force, which occurs when high-speed rotary motion pushes substances outward from a spinning axis, creating thousands of G-force (gravity) to increase the speed of separation.

The principle of separation in this topic is employed to segregate mixtures of immiscible liquids or liquids/solids of different densities. A classic example of this application would be the separation of water, oil and dirt. Natures method of separating immiscible mixtures is sedimentation, which allows the force of gravity to pull down higher density substances to the bottom.

The sedimentation process is slow and fine particles will remain suspended in the liquid. In various industries, centrifuges have been used to replace sedimentation as a means of performing the following tasks:

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