High shear mixers go by various other names, such as rotor-stator mixers, high shear homogenizers, and high shear reactors. They disperse, dissolve, grind, homogenize, and emulsify different ingredients during the same phase or in different phases. This type of mixer has a high shear rate, localized energy dissipation rate, and high rotor tip speed. It also consumes more power than an ordinary mixer.
The shearing force of the mixer mixes the ingredients both by using its stationary parts and rotating parts. Stationary parts include baffles, vanes, and walls of the mixing chamber. On the other hand, the rotating parts include paddles, screws, and a set of impellers. A high shear mixer is a crucial piece of equipment in various industries, like plastic, cosmetics, pharmaceuticals, and food manufacturing.
The operating principle of a high shear mixer depends on three things:
1. Emulsion homogenization
Emulsion homogenization requires uniform sizes of each liquid droplet to create a mixture in one continuous phase. The liquid droplets in the dispersed phase remain suspended, thus allowing the natural separation to take place between the two phases. This is crucial if you want to mix oil and water thoroughly.
2. Suspension homogenization
Sometimes, the mixer may have to mix solid particles by breaking them down. The suspension homogenization principle points out how the mixer first breaks the large particles down and then disperses them according to their sizes.
3. Particle-size reduction
This is similar to suspension homogenization. It mills down solid or semi-solid ingredients into finer particles to make it easier for the paddles and impellers to mix them with the rest of the ingredients.
You may come across an acoustic mixer that has a similar working principle as a high shear mixer. Go for the high shear model as it has higher viscosity that ensures thorough mixing of all the ingredients.