Particle Size Control/Classification
Air Classification and sieving are the two most common mechanical procedures that can be used to control particle size.
Air classifiers use a technique by which dry powders of mixed particle size are separated into two distinct fractions, either side of a specified cut point. They are highly versatile and can be used for the production of powders with a particle size anywhere between 1 micron and 300 microns. The technology is based on the generation of differential forces on the particles of different sizes within an air system.
The same technology can be applied to the separation of the constituent parts of a powder mixture in which the underlying fractions experience different forces within the air system by virtue of their shape, density or mass, rather than their particle size alone. Common applications involve the removal of contamination in primary production environments or the separation and recovery of specific materials in recycling operations.
Vibratory sieving technology is used to separate contamination or to grade products into specified size categories, or fractions, usually of 40 microns or higher, by using a mesh, net or some other similar method. It is used extensively in the food industry for check-sieving.
British Rema offers the following classifier and industrial sieving product ranges:
Aerosplit Classifier - a high efficiency air-swept classifier for ultrafine powders. Units can operate in stand-alone or closed-circuit systems and are used primarily for products down to 1 micron.
Rotary Classifier Mill - a fixed beater impact grinder embodying two-stage grinding with integral classification rotor.
Unit Air Separator - a self-contained, gravity-fed, forced-vortex high-volume separator for a wide range of general applications for products from 25 to 300 microns
Minisplit Classifier - a self-contained, precision-built classification system developed for research, or small production applications. Particle size range is typically from 1 micron to 75 microns.
Static Vane Classifier - an airborne-fed, free-vortex unit for the classification of dry powders with particular application in closed-circuit grinding systems.