Template:Model theory (Text, Screen Multi-row)

Figure {{{Figure1}}} indicates a typical arrangement of screen panels on a screen deck. Each row of panels may exhibit a unique set of properties. Particles in the screen feed may therefore experience changing apertures sizes or open area fractions during screening, in the order of row arrangement in the flow direction.

Screening across the rows of a deck with differing properties is analogous to an arrangement of screens in series, where the oversize from the first screen (row) becomes the feed to the next screen (row), and so on. This concept is illustrated in Figures {{{Figure2}}} and {{{Figure3}}}.

Mathematically, this is stated as:

$(E_{\rm {{oc}i}})_{\rm {Deck}}=(E_{\rm {{oc}i}})_{1}\times (E_{\rm {{oc}i}})_{2}\times \dots \times (E_{\rm {{oc}i}})_{p}=\prod _{k=1}^{p}{(E_{\rm {{oc}i}})_{k}}$

and adjusted for the entrainment of fines by:

$(E_{{\rm {oa}}i})_{\rm {Deck}}=(E_{{\rm {oc}}i})_{\rm {Deck}}+\left(1-(E_{{\rm {oc}}i})_{\rm {Deck}}\right)\cdot R_{\rm {f}}\exp(-\lambda {\bar {d}}_{i})$

where:

• $(E_{\rm {{oc}i}})_{\rm {Deck}}$ is the corrected fraction of the feed to the screen deck in size interval $i$ recovered to the deck oversize stream (frac)
• $(E_{\rm {{oc}i}})_{k}$ is the corrected fraction of the feed to panel row $k$ in size interval $i$ recovered to the row oversize stream (frac)
• $(E_{\rm {{oa}i}})_{\rm {Deck}}$ is the actual fraction of the feed to the screen deck in size interval $i$ recovered to the deck oversize stream (frac)
• $p$ is the number of panel rows with apertures permitting the passage of particles

Classification for each row is computed via the modified Whiten and White equation presented above. The same $n_{\rm {L}}$ parameter is applied to all rows as a simplification.