Mixing and Stirring
Mixing and stirring is the most common application in a laboratory or even in other industry such as for Bio-medicine, Food, Daily chemicals, Fine chemicals, Petrochemicals. Mixing and stirring goes a long way from minor applications to industrial size. From magnetic stirrer to overhead, high shear, and even to reactor size.
A magnetic stirrer or magnetic stir plates is most commonly used in laboratories such as in chemistry and biology, to ensure liquid samples are homogeneous in its consistency and temperature. They are preferred over gear-driven motorized stirrers as they are quieter and have no other external parts to break or wear out other than the magnetic stir bar itself. Magnetic stir bars are used to complete the mixing process in a magnetic stirrer. They are commonly used for chemical reactions, as glass or plastic does not affect a magnetic field. The limitation of a magnetic stirrer comes into play when the liquid are more than 4 liters due to the limited size of magnetic stir bar. as well as viscous liquids or thick suspensions. For these limitation, a mechanical stirring is typically needed, such as the overhead stirrer.
The Overhead stirrer, is another method for mixing samples, and can be adjusted accordingly to the agitation. Armed with multiple types of agitators, for various functions such as the dissolving agitator, which can be use to disperse and dissolve powders and liquids, Fold, Bend types which regulate either axial or radical flow, etc. The capability of an overhead stirrer is that it can stir high capacity up to about 20-30 Liters at least, and also the working viscosity which can go from 0 to 150000 Centipose depending on model. An overhead stirrer is typically used with a stand with base, which the stirrer is mounted on, as well as the wide variety of agitator that is available to be changed accordingly.
In case you might ask the question on how to select the correct mixer for your application, here are some question that you can start by asking yourself:
- What is the capacity of the sample?
- What is the viscosity?
- what is the material you are mixing? (Powder/Liquid, Liquid/Liquid,etc)
- What is the RPM you require to mix?
- What is the purpose of mixing? Dispersing, Emulsifying, Dissolving, Homogeneous?
High Shear Mixer
There are the standard types of overhead stirrer which allows you to control the rpm, and also there are new generations which allows you to have better control such as memory speed automatic torque compensation as well as better display properties, etc.
And if you are looking to do homogenization or emulsion, you will be looking at High shear mixers, able to mix at a higher rpm, and also various other properties.
In high shear mixing, the high speed rotation of the rotor blades within the stator exerts a powerful suction which will draw the liquid and solid materials from the top and bottom of the vessel to the center where the centrifugal force will then drive the material towards the periphery and into the gap between the stator and rotor, which will undergo dispersing, emulsifying and homogenizing. The intense hydraulic shear forces the material at high velocity through perforations in the stator to circulate within the main body of the mix. The materials are then expelled from the stator which are projected radially at high speed towards the sides of the mixing vessel. Fresh materials are continually drawn into the stator-rotor to renew the mixing cycle. for more information on the high-shear and overhear stirrer product click here
Jetmixer and Reactors
If you are looking for even bigger volume, you will be looking at the Jetmixers or reactor type mixing such as FLUKO’s Fisco which is a customized system for mixing larger volume.
The Fisco lab reactors have a working capacity of 1L, 2L, 5L and 10L, which are suitable for dispersing, emulsifying, homogenizing, mixing, reacting, fermenting, cream perpetrating, polymerizing, and synthesis reacting under vacuum or pressurized conditions. Incorporating a macro mixing system, micro emulsifying system, vacuum system, temperature control system, and multi-sensor detecting system, they can fully simulate industrial production.
More options leads to more inspiration to customize to your needs: