Maintenance Guide For Air Classifiers
Air classifiers are rugged by design, but they do
require a degree of maintenance to keep them
running at peak performance.
Maintenance Guide
for Air
A service technician
should check these
10 items to help
identify and fix
problems with air
classifiers.
by William Chapman
and William MacNeil
22
A
Classifiers
ir classifiers are normally employed
when dry material particle size for separation is too fine for screening. The
beauty of an air classification system
is that it defeats the blinding and breaking issues
associated with screening. The most significant
advantage is its dry process for de-dusting aggregates. This can, ultimately, eliminate the need for
water or settling ponds; saving money, land, and
the environment.
Air classifiers work by combining the prin-
AGGREGATES MANAGER October 2012
ciples of centrifugal and drag force, collision, and
gravity to generate a balanced high-precision
method of classifying particles according to size
and density. While density does play a role in air
classifier separation, the internal air currents are
mostly affected by the overall mass and weight
of the particles in the feed. Lighter and smaller
particles are removed by the airflow, while
heavier and larger particles are not entrained in
the airflow. If the lower-density material also has
a finer particle size, then air classifiers can be very