How Does a Centrifuge Work?

A centrifuge is any device that separates materials with varying densities. It is usually used to separate solids from liquids.

It starts working when a device such as a motor spins a compartment in an axis. This happens very quickly, often reaching hundreds and even thousands of revolutions per minute. This induces the centrifuge to produce a force that pushes away any matter, be it solid, liquid, or gas, from the center of rotation. This force is called centrifugal force.

The speed of a centrifuge is measured in revolutions per minute, or RPM. Large centrifuges generally have low RPM’s, while small centrifuges have high RPM’s. This is due to the distance that the compartment has to travel per minute.

One good way to learn how a centrifuge works is by observing a common appliance that has a centrifuge: a washing machine. When you place wet clothes inside the washing machine and activate it through a knob or button, centrifugal force works to remove the dirt from your clothes.

There is an inner tube with a set of perforated holes inside the washing machine. This tube would spin around a center axis at a specific rate. Aside from this inner tube, there is also an outer tube within the machine. While the clothes inside the washing machine are rotating, the centrifugal force pushes them against the inner tube. The water inside the machine pushes dirt through the holes to the outer tube. The outer tube then sends the water with dirt down the drain so your clothes will come out clean.