Effective
anti-blinding systems for continuous operation
When
fine screening is done, the screen meshes can become blinded by grains,
dust , or by static charges.
This
greatly reduces the capacity and the screening efficiency.
For
a continuous operation, it is necessary to have an approbpriate anti-blinding
system for the materials being screened.
The
circular design, with its central main shaft and three-dimensional
motion, enables Tumblers Screening Machines to utilize different anti-blinding
systems.
The
following systems are available:
Bouncing Ball Cleaning (1)
Special wear resistant and food grade rubber
balls are bouncing on a perforated metal plate underneath the screen
mesh. the material in the mesh is kicked out, thus reducing blinding.
this system is simple to use and easy to maintain and it used for
most of the granular materials.
Roller Brush Cleaning (2)
Roller brushes are rotating under the screen
and are used for spherical, crystalline and fragile materials. The
brush arms are driven by a reduction gear mounted in the bottom pan.
Air-jet Cleaning (3)
A blower carries air or gas into the central
air bell where it is distributed into the air-jet arms. The knive
like air-jet has a velocity of up to 120 m/s thus cleaning the mesh
from underneath. A fluid bed like effect is created by the air-jet
causing fine and coarse material to disperse. The air is being pulled
out through the fines outlet or a suction nozzle in the bottom pan.
The air-jet stream is reversed downwards above the screen while the
fine material is pulled through the mesh with the use of the vacuum,
in addition to the mechanical screening motion. This system is utilized
for difficult to screen materials like sticky, fatty, smeary, or electrostatic
charged materials, such as spices or fine plastic powders, etc.
Combined Air-Jet and Brush Cleaning (4)
Many of the very difficult materials, such as fine plastic
powders, need additional brush cleaning, along with the air-jet cleaning,
to remove the material from the mesh holes.
Straining device (5)
Stahl- Steel or rubber plates are rotating on the screen,
thus breaking up large particles andhelping pass material through
the screen. i.e. instant Coffee.
Ultra-Sonic Cleaning (6)
This is the new screening technology for very fine materials.An
ultrasonic generator, with a high frequency, produces vibrations in
the µm range which are being transmitted to the screen mesh.
This cleans the mesh and significantly increases the capacity. Good
for safety screening toner or pigments, fluorescent powders. Easy
retrofitting.
