appearing under section i, respectively. VY and VN are the total
volume of small and near-mesh size particles, respectively.
Fig. 6 demonstrates that the vibration modes have an influence
on the distribution of the small and near-mesh size particles. The
two kinds of particles have a similar distribution with a trend that
increases gradually along the longitudinal direction of the deck.
The front sections of the screen deck contain more small size particles
but fewer near-mesh size particles, while the last sections
contain fewer small size particles but more near-mesh size particles.
In addition, the volume fraction of small size particles in the
linear mode is larger than that in the circular or elliptical modes
over the first three sections, although the last two sections exhibit
the reverse situation. The volume fraction of near-mesh size particles
for the linear mode exceeds those from circular or elliptical
modes over the first four sections. But over the last two sections
the situation is reversed. The screening mode is a main factor
affecting screening efficiency and particle size distribution in addition
to the material layer thickness. This has more influence on the
near-mesh size particles than it does on the small-sized ones