Formula for calculating theoretical vibrating screen discharge end bed depth

The feed to a vibrating wire mesh screen contains a mixture of material in varying sizes. The oversized material will retard passage of the undersized material, creating a temporary restriction which results in a build-up (bed) of material on the surface of the screen.

Bed depth diminishes as the undersize material passes through the wire mesh screen apertures.

The material bed should not be allowed to reach a depth that prevents the undersize from stratifying before discharge at the wire mesh screen surface end.

Generally, the discharge end bed depth should not exceed four times the size of the wire mesh screen surface aperture when separating 100 lbs. per cubic foot material, or three times for 50 lbs. per cubic foot material.