Direct Links:
Mixtures
A good mixing is important to speed up chemical reactions and it helps to reach chemical equilibrium quickly. Therefore most chemical reactions make use of a stirrer.
The common device is the magnetic stirrer. The magnetic stirrer includes a heating plate with a mostly inaccurate controller for temperature. The stirring function is activated with a power switch and controlled by a turn-switch. A stirrer bar of appropriate size is placed in the reaction flask. The size of the stirrer bar has to fit the flask, so it can spin freely and guarantee a good mixing.
When working with suspensions the magnetic stirrer might not be powerful enough. In this case a KPG-stirrer is used. The KPG-stirrer has an electric motor, a control unit and the drive shaft. The drive shaft can be fixed to the stirrer shaft using a short hose. The stirrer blade may vary in form and size and should be picked according to the shape of the reaction flask. The stirrer shaft runs through the stirrer bearing, which can be connected to the flask using its ground joint. A lubricant is needed to reduce the friction between shaft and bearing. A few drops of a silicone oil are sufficient for this matter. When activating the KPG-stirrer a slow speed should be selected, the speed can be adjusted later.