Glossary to Industrial Screening
clamp bar
Metal edge used to stretch and/or to fasten the screen section.
crimp
Successive bends in a wire which result from preforming or weaving.
feed
Material supplied to a screen for a screening process.
fines
Particles smaller than a specified size.
frequency
For vibrating screens, the number of oscillations made by the screen per unit of time, expressed in hertz (Hz).
grizzly
Rugged screen comprising fixed or moving bars, discs, or shaped tumblers or rollers, normally used for screening comparatively large particles, e. g. greater than100 mm.
guard screen
Screen used to prevent the entry into a machine of coarse particles which might interfere with its operation.
horizontal screen
Vibrating screen with a motion which is substantially in a straight line in the vertical plane, normally installed horizontally, but may be inclined up to 8°.
high speed screen
Inclined screen, with a rectilinear or circular oscillating motion, normally operated at a frequency greater than 20 Hz.
hook strip
The fabrication on the edges of a screen section for holding or tensioning purposes.
inherent moisture; contained moisture
Liquid, usually water, held within a sample of a material, normally expressed as a percentage of the sample mass.
inclined screen
Vibrating screen with a rectilinear or circular oscillating motion, normally installed at an angle between 10° and 36°.
mesh count
Number of apertures per unit of linear measure in a woven wire cloth or wire screen.
nominal size
The particle size used to describe a product of a sizing operation.
near-sized material; near mesh material
Particles approximat ing in size to the aperture size of the screening surface.
overflow
That portion of the feed discharged from the screening surface without having passed through the apertures.
oversize
Screened product of a size greater than a specified size.
particle (deprecated: grain)
Discrete element of the material to be screened regardless of its size.
particle size; sieve size of a particle
Smallest sieve aperture through which a particle will pass if pre sented in the most favourable attitude.
per cent solids
Ratio of dry solids to the total solid-liquid mixture of material, expressed as a percentage by mass.
percentage open area
For woven wire cloth and wire screens, the ratio of the total area of the apertures to the total area of the cloth or the screen.
plain weave
Weave in which every warp wire crosses alternately above and below every weft wire and vice versa.
pegging
The condition where particles wedge in the screen appertures.
pitch
Distance between corresponding points of two adjacent apertures in a woven wire cloth, a wire screen or a perforated plate.
product
In general, the mate rial resulting from any operation. In particular, the final material produced from a series of operations; e. g. screened product, finished product,etc
relative density (deprecated: specific gravity)
Ratio of the mass in air of a solid particle of a given volume to the mass of an equal volume of water.
resonance screen
Screen with a period of oscillation close to the natural period of oscillation of the resilient mounting.
relieving deck
Screen, mounted above another screen, with apertures normally at least twice the size of those in the lower deck, used to reduce the load and wear of the lower screening surface.
reciprocating screen; jig ging screen
Screen or pair of screens to which a combined horizontal and vertical motion is imparted by a crank shaft and connecting rods, the screen ing surfaces being horizontal or in clined at a small angle.
revolving screen; trommel
Screen in which the screening surface is formed into a cylinder or frustum of a cone, mounted on a horizontal or near horizontal rotating shaft or on revolving rollers. The material to be screened is fed into the interior of the revolving screen.
rinsing
Removal by spraying, usually with water, of fine or foreign material present among or adhering to larger particles.
type of weave
The way in which warp and weft wires cross each other.
twilled weave
Weave in which every warp wire crosses alternately above and below every second weft wire and vice versa.
undersize control screen; breakage screen
Screen used for the removal of undesirable undersize from a material.
underflow
That portion of the feed which has passed through the apertures of a screening surface.
undersize
Screened product of a size smaller than a specified size.
vibrating screen
Screen oscillated either by mechanical or by electrical means.
woven wire cloth; wire screen
Screening surface, produced by a wire weaving process or by pressure-welding of two layers of parallel wires. The wires form square or rectangular apertures of uniform size. They may be precrimped before weaving.
wire diameter
Diameter of the wire for a woven wire cloth, as measured before weaving.
warp
All wires running length wise of the cloth as woven.
weft; shoot
All wires running crosswise of the cloth as woven.
wet screening
Screening with the aid of a liquid, usually in the form of a spray.