DISC-TYPE GRADING MACHINE Russian patent published in 1994 - IPC

FIELD: grading of materials. SUBSTANCE: grading machine comprises drive shafts with discs arranged in a staggered order on adjacent shafts which make a sifting surface in the form of zones, each having an identical size of holes. Hole size grows in each subsequent zone by twice the hole size increment while the linear speed of the disc generating line in each next zone is larger than that of the preceding zone by the value proportionate to the increment of disc diameters. Shaft axles of each following zone are disposed below the shaft axles of the foregoing zone by the value of increment in the hole size. EFFECT: improved design. 2 dwg