Title: Characterization of the Centrifugal Mill
1- Characterization of the Centrifugal Mill
- by Lumped Kinetic Math Model and Discrete Element
Model - T. Inoue and K. Okaya
- Department of Earth System Engineering,
- University of Tokyo
2Centrifugal Mill
Eccentricity Acceleration Coefficient
3Force balance in centrifugal mill (Bradley et al.)
4Theoretical Model (Bradley et al.)
5Upper limit of phase angle (theoretical)
6Mill Solver - A 2-D DEM Model -1
7Mill Solver - A 2-D DEM Model -2
8Mill Solver - A 2-D DEM Model -3
9Effect of mill diameter (D) on mill power,
determined by DEM simulation.
10Effect of ball density on mill power, determined
by DEM simulation
11Effect of centrifugal coefficient (z) on mill
power and energy consist,determined by DEM
simulation -1
12Effect of centrifugal coefficient (z) on mill
power and energy consist,determined by DEM
simulation -2
13Effect of eccentricity (G/D) on mill power,
determined by DEM simulation
14Effect of ball filling (J) on power draft,
determined by DEM simulation
15Effect of eccentricity (G/D) on energy
dissipation pattern
Energy Consist
16Effect of friction coefficient and restitution
coefficient on power draft -1
17Effect of friction coefficient and restitution
coefficient on power draft -2
18Effect of Restitution Coefficient on Power
Dissipation
19Weighted density distribution of energy spectrum
20Theoretical (Bradley et al.)
DEM simulation (Inoue-Okaya)
21Specification of prototype X-Mill
Type Double cylinder self- balancing
centrifugal mill Mill Operation Batch or
continuos Dimension of 150 mm dia. Mill
cylinders 300 mm length Eccentricity
(G/D) 0.2 Grinding media 17 kg (for steel
balls) Equipment size 762 (W) 935 (H)
1190 (L) mm Motor 7.5 kW
22X-Mill
23X-Mill (prototype)
24X-Mill (prototype) in motion
25Batch grinding (quartz)
26Continuous grinding (quartz)
27Autogenous grinding (limestone)
28Figure 2. Phase angle of the centrifugal mill
estimated from math model.
29Figure 3. Net power draft of the centrifugal mill
estimated from math model
30Figure 4. Phase angle of the centrifugal mill
estimated from math and simulator models.
31Figure5. Net power draft of the centrifugal mill
estimated from math and simulator models.
32Conclusion
- Theoretical model can present approximate but
clear view of the equipment property in the
form of a simple equation - DEM simulation can present a more realistic
vision of the equipment and its performance - DEM simulation can present the property of
the possible mill design under less
restriction and less expenses - DEM simulation gives a microscopic view of
the comminution events together with their
integral effects in realistic figures