386
M. Weers et al.
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
0.0
0.5
1.0
1.5
2.0
grade efficiency T(x) /
-
particle size x / mm
8_880
9_1000
10_1100
11_1200
12_1400
13_1550
Fig. 37 Grade efficiency function of different number of revolution of circular vibrating screen
Fig. 38 Sharpness of cut κ
and cut size x t as a function
of revolution rate
0,6
0,7
0,8
0,9
1,0
1,1
1,2
900
1000 1100 1200 1300 1400 1500 1600
cut size / μm and kappa / -
revolution rate / min -1
cut size
sharpness of cut
Here the accelerations, which also affect the particles, are characterized. Due to
the higher revolution rate, the particles are accelerated stronger, thus being moved
further and transported faster through the sieve. As a result, there is a less frequent
comparison between mesh size and particle size.
In a further step, the local distribution of the particles in the collection containers
(cf. Fig. 39) was investigated at different times (t 1 = 1 min, t 2 = 2 min and t 3 =
10 min) at a revolution rate of 1200 min
−1 .
Fig. 39 Collecting container under the screening machine