SmartScreen technology enhances sub-millimeter particle
separation
Bateman Engineering and Smart Screen Systems Inc. of Minnesota,
USA are now marketing Smart Screen's patented screening system to
mineral processors in the African and Australian markets, as well
as into Bateman Engineering projects globally.
This innovative system permits the screening of fine particulate
material with lower energy consumption, noise generation and maintenance
cost than is possible with conventional systems.
Generally, large screen motions are required for the separation of
particles of different sizes. In SmartScreens the screening surface
is suspended on set springs designed to resonate at the desired operating
frequency with an optimal balance of motion parallel and perpendicular
to material flow. Because the side plates that support the drive assembly
in a conventional screen have been eliminated, the weight of the screen
panel is minimised so that only relatively low vibratory forces are
needed for the screening motion.
Energy-saving electromagnetic motors and specially designed resonators
to amplify the motion cause the screen panel to vibrate. The resonance
desired for effective separation is maintained by a controller, accelerometer
and feedback loop, which account for variations in the material load
on the screen.
The SmartScreen design imparts many advantages. The driving force
is minimised by keeping the screen at near resonance - it theoretically
would approach zero at full resonance. Also, by tuning the springs
supporting the screen panel, energy usage by the machine is maximised.
Field experience shows that the power consumed during conventional
screening is reduced by between 50 % and 70 % when using SmartScreens.
The total energy saving, projected over the entire processing circuit,
was estimated at 5 %. Process control and efficiency of separation
is also better than is possible with either hydro-cyclones or conventional
screening systems, which increases the productivity and the quality
of the concentrate. For example, an efficiency of more than 85 % was
obtained when separating the iron fines with a cut size of 70 m in
a feed from a secondary ball mill at a concentrator.
The elimination of the side plates on the screen panel means the
footprint of a SmartScreen is not much larger than the screening area,
providing high screening capacity per machine footprint.
SmartScreen has no bearings, bushes, shafts or other moving parts,
meaning minimal maintenance and no lubrication. The light-weight construction
also means that a screen panel can be replaced in a matter of minutes
and that any motor, should it need attention, can easily be attended
to. SmartScreen has an electronic test facility in the control panel
to permit regular maintenance checks.
The screens were first used in taconite concentrators to screen fine
iron-ore concentrate, one of the most difficult materials to screen
effectively. Nearly 50 are already being used for this purpose to
obtain cut sizes between 70 m and 124 m, with a further eight being
used to process a vanadium mineral with a cut size of 150 m.
Tests are underway on material outside of this range. Besides minerals
processing, it is anticipated that SmartScreen Systems will also have
wide application in the food and agriculture industries.
Additional information on SmartScreen may be obtained from
Craig Gilbert, Manager, Processing Technologies, or
Tammy Gazis, Product Engineer, on +27-11-201-2300 or engtech@BatemanEngineering.com.
