An agitator is an element of a process unit intended to ensure the homogenization of a medium (homogenization from the point of view of the components of the medium and/or the temperature).
There are different types of agitators depending on the environment/medium, unit’s configuration and desired effect.
In the laboratory field, the agitation of a solution can be carried out by a glass rod that allows a solution to be stirred in a receptacle. The agitation is said manual. Its use can be replaced by a magnetic bar in combination (or not) with a hotplate. The agitator is then the block that allows to stir the magnetic bar. It consists of a magnet rotated by a variable speed motor.
Before the advent of stirrers and magnetic stirring rods, agitation in the laboratory was realized by a motor that rotated a rod dipping vertically into the solution. The wand passed the case through the condenser. This rod was terminated by a blade of a shape and size adapted to the container containing the solution to be agitated.