Guide of Industrial Dispersion Best Practices

Basic concepts

Basic concepts

Important for the Donut effect

Dispersion

Micronized solids

Energy

Viscous liquid medium

High shear stress

Dispersion

Solid particles : DisaggregatedWeted surfaceUniformely distributed

The dipersion process

Agglomerates Aggregates

More easier to break agglomerates Aggregates won’t be dispersed by disc Particule size < 1 µm but after dispersion it’s difficult to be inferior at 40/50 µm

Agglomerates : when particles are joined loosely together which can be simply broken by mechanical forces

Aggregates: assembly of particles bonded strongly

The dipersion process

Dispersion

The Donut Effect

• The geometry of the dispersion container• The disc diameter• The peripheral velocity : 18 – 25 m/s• The height of the dissolver disc above the bottom of the vessel

Key parameters:

Definition When vortex allows seing the interior part of disc but not teeth Ideal mode for dispersion Important to keep a laminar flow and not turbulent flow

Flux patern Planetary system

1 path 5/6 path 1’

Translation movment

Types of blades

Standard Low /medium viscosity

Liquid product

Increase axial capacity

High mixing capacity Only for mixingDispersion capacity

Can improve incorporation or dispersion

Comparative agitation /dispersion

Better dispersion

Better agitation

Thermal balance

Process

High shear stress = Exothermic reaction

Final temperature product

Important to control the temperature during the process

Correctors to decrease temperature :

• Avoid unnecessary dispersion effective

• Raw Materials addition = dilution effective

• Heating/ Cooling jacket effective

Teeth of disc and impact on the dispersion

12

Used disc

New disc

20 mm

To choose the better height improve the dispersion

Better vortex

Adjustable height

Telescopic shaft

Donut effect