Section 72.—RIDDLING AND SCREENING.
[1256]. Square mesh wire gauze.
[1257]. Perforated plate.
[1258]. Parallel bars or wires.
[1259]. Hexagon or triangular mesh wire work.
[1260]. Slit and square hole perforations, used for seeds, &c.
A form of variable mesh is manufactured by parallel series of diagonal bars jointed by pins to sliding cross-bars, so that the angle of the mesh bars can be altered and thus the spaces reduced or enlarged, on the same principle as [No. 617].
[1261]. Sloping screen.
[1262]. Cylindrical or slope reel screen.
[1263]. Cylindrical graduated screen or sizer.
[1264]. Rotary screen, with rolling bevil gear motion. See [No. 711].
[1265]. Rotary horizontal screen.
[1266]. Shaking or jigging screen. Sometimes supplied with a blast or aspirator to carry off the lighter particles.
[1267]. Eccentric or angular barrel screen or mixer.
[1268]. Air blast sizing or graduating apparatus.
[1269]. Edison’s magnetic sizing apparatus for iron or steel particles.
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[1270]. Graduating or sizing screens, either fixed as shown or kept in motion like [No. 1266].
See also Concentrating and Separating, [Section 26].