Figure 1.
The new high-efficiency three separation classifier: (a) geometry, (b) parts, and (c) dimensions of the new rotor-type dynamic classifier; 1—air and fine outlet, 2—rotor cage, 3—diversion cone, 4—coarse powder outlet, 5—transmission shaft, 6—classification chamber, 7—cone, and 8—feeding and air inlet.
Figure 1.
The new high-efficiency three separation classifier: (a) geometry, (b) parts, and (c) dimensions of the new rotor-type dynamic classifier; 1—air and fine outlet, 2—rotor cage, 3—diversion cone, 4—coarse powder outlet, 5—transmission shaft, 6—classification chamber, 7—cone, and 8—feeding and air inlet.
Figure 2.
CFD grid and boundary conditions of the simulated classifier.
Figure 2.
CFD grid and boundary conditions of the simulated classifier.
Figure 3.
The radial velocity for four different mesh numbers.
Figure 3.
The radial velocity for four different mesh numbers.
Figure 4.
Velocity distribution on the outer surface of the rotor cage: (a) tangential velocity and (b) radial velocity.
Figure 4.
Velocity distribution on the outer surface of the rotor cage: (a) tangential velocity and (b) radial velocity.
Figure 5.
Comparison of radial velocity contours and gas pathlines in the classifying chamber: (a) T-A(1-1), (b) T-B(1-0.9), (c) T-C(1-0.8), (d) T-D(1-0.7), (e) T-E(1-0.6), and (f) T-F(1-0.5).
Figure 5.
Comparison of radial velocity contours and gas pathlines in the classifying chamber: (a) T-A(1-1), (b) T-B(1-0.9), (c) T-C(1-0.8), (d) T-D(1-0.7), (e) T-E(1-0.6), and (f) T-F(1-0.5).
Figure 6.
Location of the sampling points.
Figure 6.
Location of the sampling points.
Figure 7.
Radial velocity distribution at different heights in the classifying chamber: (a) T-A(1-1), (b) T-B(1-0.9), (c) T-C(1-0.8), (d) T-D(1-0.7), (e) T-E(1-0.6), and (f) T-F(1-0.5).
Figure 7.
Radial velocity distribution at different heights in the classifying chamber: (a) T-A(1-1), (b) T-B(1-0.9), (c) T-C(1-0.8), (d) T-D(1-0.7), (e) T-E(1-0.6), and (f) T-F(1-0.5).
Figure 8.
Trajectories of different size particles in T-A(1-1): (a) d = 5 μm, (b) d = 15 μm, (c) d = 25 μm, and (d) d = 35 μm.
Figure 8.
Trajectories of different size particles in T-A(1-1): (a) d = 5 μm, (b) d = 15 μm, (c) d = 25 μm, and (d) d = 35 μm.
Figure 9.
Trajectories of different size particles in T-B(1-0.9): (a) d = 5 μm, (b) d = 15 μm, (c) d = 25 μm, and (d) d = 35 μm.
Figure 9.
Trajectories of different size particles in T-B(1-0.9): (a) d = 5 μm, (b) d = 15 μm, (c) d = 25 μm, and (d) d = 35 μm.
Figure 10.
Trajectories of different size particles in T-C(1-0.8): (a) d = 5 μm, (b) d = 15 μm, (c) d = 25 μm, and (d) d = 35 μm.
Figure 10.
Trajectories of different size particles in T-C(1-0.8): (a) d = 5 μm, (b) d = 15 μm, (c) d = 25 μm, and (d) d = 35 μm.
Figure 11.
Trajectories of different size particles in T-D(1-0.7): (a) d = 5 μm, (b) d = 15 μm, (c) d = 25 μm, and (d) d = 35 μm.
Figure 11.
Trajectories of different size particles in T-D(1-0.7): (a) d = 5 μm, (b) d = 15 μm, (c) d = 25 μm, and (d) d = 35 μm.
Figure 12.
Trajectories of different size particles in T-E(1-0.6): (a) d = 5 μm, (b) d = 15 μm, (c) d = 25 μm, and (d) d = 35 μm.
Figure 12.
Trajectories of different size particles in T-E(1-0.6): (a) d = 5 μm, (b) d = 15 μm, (c) d = 25 μm, and (d) d = 35 μm.
Figure 13.
Trajectories of different size particles in T-F(1-0.5): (a) d = 5 μm, (b) d = 15 μm, (c) d = 25 μm, and (d) d = 35 μm.
Figure 13.
Trajectories of different size particles in T-F(1-0.5): (a) d = 5 μm, (b) d = 15 μm, (c) d = 25 μm, and (d) d = 35 μm.
Figure 14.
Comparison of Tromp curves for six different rotor cage models: (a) 13.5 m/s–470 rpm, (b) 16 m/s–470 rpm, and (c) 13.5 m/s–670 rpm.
Figure 14.
Comparison of Tromp curves for six different rotor cage models: (a) 13.5 m/s–470 rpm, (b) 16 m/s–470 rpm, and (c) 13.5 m/s–670 rpm.
Figure 15.
Structure of the diversion cone at different heights.
Figure 15.
Structure of the diversion cone at different heights.
Figure 16.
Effect of the height of the diversion cone on the radial velocity (T-C(1-0.8), x = 0): (a) h = 94 mm, (b) h = 104 mm, and (c) h = 114 mm.
Figure 16.
Effect of the height of the diversion cone on the radial velocity (T-C(1-0.8), x = 0): (a) h = 94 mm, (b) h = 104 mm, and (c) h = 114 mm.
Figure 17.
Effect of the height of the diversion cone on the axial velocity (T-C(1-0.8), x = 0): (a) h = 94 mm, (b) h = 104 mm, and (c) h = 114 mm.
Figure 17.
Effect of the height of the diversion cone on the axial velocity (T-C(1-0.8), x = 0): (a) h = 94 mm, (b) h = 104 mm, and (c) h = 114 mm.
Figure 18.
Effect of the height of the diversion cone on the radial velocity (T-D(1-0.7), x = 0): (a) h = 94 mm, (b) h = 104 mm, and (c) h = 114 mm.
Figure 18.
Effect of the height of the diversion cone on the radial velocity (T-D(1-0.7), x = 0): (a) h = 94 mm, (b) h = 104 mm, and (c) h = 114 mm.
Figure 19.
Effect of the height of the diversion cone on the axial velocity (T-D(1-0.7), x = 0): (a) h = 94 mm, (b) h = 104 mm, and (c) h = 114 mm.
Figure 19.
Effect of the height of the diversion cone on the axial velocity (T-D(1-0.7), x = 0): (a) h = 94 mm, (b) h = 104 mm, and (c) h = 114 mm.
Figure 20.
Tromp curves for different height diversion cone classifiers: (a) T-C(1-0.8) and (b) T-D(1-0.7).
Figure 20.
Tromp curves for different height diversion cone classifiers: (a) T-C(1-0.8) and (b) T-D(1-0.7).
Figure 21.
Structure of the diversion cone at different diameters (T-C(1-0.8)).
Figure 21.
Structure of the diversion cone at different diameters (T-C(1-0.8)).
Figure 22.
Effect of the diameter of the diversion cone on the axial velocity and gas movement (T-C(1-0.8), x = 0): (a) d = 176 mm, (b) d = 198 mm, (c) d = 220 mm, and (d) d = 242 mm.
Figure 22.
Effect of the diameter of the diversion cone on the axial velocity and gas movement (T-C(1-0.8), x = 0): (a) d = 176 mm, (b) d = 198 mm, (c) d = 220 mm, and (d) d = 242 mm.
Figure 23.
Effect of the diameter of the diversion cone on the radial velocity (T-C(1-0.8), x = 0): (a) d = 176 mm, (b) d = 198 mm, (c) d = 220 mm, and (d) d = 242 mm.
Figure 23.
Effect of the diameter of the diversion cone on the radial velocity (T-C(1-0.8), x = 0): (a) d = 176 mm, (b) d = 198 mm, (c) d = 220 mm, and (d) d = 242 mm.
Figure 24.
Effect of the diameter of the diversion cone on the axial velocity and gas movement (T-D(1-0.7), x = 0): (a) d = 154 mm, (b) d = 173.3 mm, (c) d = 192.5 mm, and (d) d = 211.7 mm.
Figure 24.
Effect of the diameter of the diversion cone on the axial velocity and gas movement (T-D(1-0.7), x = 0): (a) d = 154 mm, (b) d = 173.3 mm, (c) d = 192.5 mm, and (d) d = 211.7 mm.
Figure 25.
Effect of the diameter of the diversion cone on the radial velocity (T-D(1-0.7), x = 0): (a) d = 154 mm, (b) d = 173.3 mm, (c) d = 192.5 mm, and (d) d = 211.7 mm.
Figure 25.
Effect of the diameter of the diversion cone on the radial velocity (T-D(1-0.7), x = 0): (a) d = 154 mm, (b) d = 173.3 mm, (c) d = 192.5 mm, and (d) d = 211.7 mm.
Figure 26.
Tromp curves for different diameter diversion cone classifiers: (a) T-C(1-0.8) and (b) T-D(1-0.7).
Figure 26.
Tromp curves for different diameter diversion cone classifiers: (a) T-C(1-0.8) and (b) T-D(1-0.7).
Figure 27.
(a) Process flow diagram of the grinding and classifying system and (b) photo of the industrial classifier.
Figure 27.
(a) Process flow diagram of the grinding and classifying system and (b) photo of the industrial classifier.
Figure 28.
(a) The particle size distribution of the coarse and fine powders and (b) Tromp curves for the industrial classifier.
Figure 28.
(a) The particle size distribution of the coarse and fine powders and (b) Tromp curves for the industrial classifier.
Table 1.
Dimensional parameters of the rotor cage model.
Table 2.
Mesh number of the model and near-wall grid height for the new rotor-type dynamic classifier.
Table 2.
Mesh number of the model and near-wall grid height for the new rotor-type dynamic classifier.
Domain | Mesh Number | Near-Wall Grid Height/mm |
---|
Feeding part | 436,185 | 5.0 |
Rotor cage | 224,640 | 1.8 |
Diversion cone part | 293,632 | 3.9 |
Coarse powder collection area | 379,104 | 5.0 |
Fine powder collection area | 408,800 | 5.0 |
Particle classification area | 363,008 | 3.7 |
Sum | 2,105,369 | |
Table 3.
Comparison of simulated and experimental pressure drop .
Table 3.
Comparison of simulated and experimental pressure drop .
Model | V/m·s−1 | n/rpm | Numerical Simulation Value/Pa | Experimental Value/Pa | Relative Error/% |
---|
T-A(1-1) | 13.5 | 470 | 276.5 | 285.5 | 3.15 |
13.5 | 600 | 302.1 | 315.0 | 4.09 |
T-D(1-0.7) | 13.5 | 470 | 225.3 | 229.5 | 1.83 |
13.5 | 600 | 255.5 | 270.6 | 5.58 |
Table 4.
Standard deviation comparison of velocity for different rotor cage models.
Table 4.
Standard deviation comparison of velocity for different rotor cage models.
| Position | T-A(1-1) | T-B(1-0.9) | T-C(1-0.8) | T-D(1-0.7) | T-E(1-0.6) | T-A(1-0.5) |
---|
radial velocity/m·s−1 | Position 1 | 2.49 | 1.95 | 1.51 | 1.63 | 1.99 | 2.17 |
Position 2 | 2.43 | 1.94 | 1.52 | 1.65 | 1.89 | 2.16 |
Position 3 | 2.43 | 1.97 | 1.48 | 1.67 | 1.96 | 2.18 |
Position 4 | 2.46 | 1.96 | 1.48 | 1.60 | 2.01 | 2.15 |
deviation average/m·s−1 | 2.45 | 1.96 | 1.49 | 1.64 | 1.97 | 2.17 |
tangential velocity/m·s−1 | Position 1 | 1.44 | 0.97 | 0.87 | 1.10 | 1.35 | 1.32 |
Position 2 | 1.36 | 0.95 | 0.87 | 1.11 | 1.32 | 1.30 |
Position 3 | 1.40 | 0.98 | 0.88 | 1.05 | 1.29 | 1.28 |
Position 4 | 1.43 | 1.01 | 0.86 | 1.10 | 1.25 | 1.33 |
deviation average/m·s−1 | 1.41 | 0.98 | 0.87 | 1.09 | 1.31 | 1.30 |
Table 5.
Comparison of d50 and K for the six different rotor cage models (13.5 m/s–470 rpm).
Table 5.
Comparison of d50 and K for the six different rotor cage models (13.5 m/s–470 rpm).
Model Code | d50/μm | K |
---|
T-A(1-1) | 26.0 | 0.42 |
T-B(1-0.9) | 25.6 | 0.63 |
T-C(1-0.8) | 22.5 | 0.72 |
T-D(1-0.7) | 22.3 | 0.71 |
T-E(1-0.6) | 26.5 | 0.64 |
T-F(1-0.5) | 35.0 | 0.59 |
Table 6.
Comparison of d50 and K for the six different rotor cage models (16 m/s–470 rpm).
Table 6.
Comparison of d50 and K for the six different rotor cage models (16 m/s–470 rpm).
Model Code | d50/μm | K |
---|
T-A(1-1) | 29.1 | 0.47 |
T-B(1-0.9) | 29.3 | 0.67 |
T-C(1-0.8) | 24.8 | 0.74 |
T-D(1-0.7) | 25.2 | 0.75 |
T-E(1-0.6) | 29.7 | 0.68 |
T-F(1-0.5) | 39.1 | 0.61 |
Table 7.
Comparison of d50 and K for the six different rotor cage models (13.5 m/s–670 rpm).
Table 7.
Comparison of d50 and K for the six different rotor cage models (13.5 m/s–670 rpm).
Model Code | d50/μm | K |
---|
T-A(1-1) | 24.1 | 0.52 |
T-B(1-0.9) | 23.9 | 0.69 |
T-C(1-0.8) | 18.9 | 0.77 |
T-D(1-0.7) | 20.1 | 0.79 |
T-E(1-0.6) | 24.4 | 0.67 |
T-F(1-0.5) | 31.3 | 0.65 |
Table 8.
Raw material particle size distribution.
Table 8.
Raw material particle size distribution.
Particle Size/μm | Differential Distribution/% |
---|
0–10 | 9.04 |
10–20 | 6.20 |
20–30 | 3.32 |
30–40 | 5.30 |
40–50 | 4.46 |
50–60 | 7.81 |
60–70 | 10.40 |
70–75 | 0.80 |
>75 | 52.67 |