What Is a Disperser?
A disperser is a device used for dispersing a target substance in a liquid or gas.
In liquid dispersers, dispersion is achieved through varying speeds, collision with beads or agitator blades, or by employing ultrasonic waves.
Airborne dispersers include ejector-type dispersers, venturi-type dispersers, orifices, and more. These devices disperse target substances into gas by breaking down their agglomerates.
Uses of Dispersers
Dispersers find applications in a wide range of fields, including inks, paints, chemicals, electronic materials, and food products.
The production of inks and paints serves as a typical example of disperser usage. Pigments, the primary raw materials in these products, are often dried and agglomerated, necessitating dispersion in a solvent during the manufacturing process.
Particle size, particle size distribution, and particle shape significantly influence the performance of pigments.
Principles of Dispersers
Dispersers employ various dispersion methods depending on the type of equipment used. Shearing action and impact/collision action are the fundamental principles behind dispersion.
In high-speed rotary shear agitators, colloid mills, or roll mills, intense shear stress occurs within the gap between the rotor and the outer casing. Aggregates of particles or the particles themselves are made finer and dispersed due to this shear stress. Increasing shear speed and the solvent’s viscosity can enhance the generated shear stress.
In agitator tanks, vessel-driven mills, and media stirred mills, impact and collision actions are primarily used. Increasing the agitation speed or the use of a medium can amplify the impact.