Abstract: A roll (110) sorter includes a pair (111) of counter-rotating rollers (112,114) separated by a gap (124). A sorting region (128) is defined by the gap and the facing roller surfaces (130,132). Particles (46) fed into the sorting region float on the rollers and are sorted into two groups, those that pass through the gap and those that cannot pass through the gap. The accuracy of the sorter is increased by associating a metering facility (220) such as a gate (222) with the sorting region. The metering facility limits the number of particles which can simultaneously enter the sorting region. Typically, the particles enter and move along the sorting region one-at-a-time and in single file.

Abstract: A roll sorter (110) includes two counter-rotating, circular cross-section, spaced rollers (112,114) defining a gap (124) therebetween. Particles 46 float on the rollers (112,114) within a sorting region (128) and are sorted by passing through the gap (124) or not so passing and being retained in the sorting region (128). The particles (46) are prevented from hopping or jumping out of the sorting region (128) by a circular cross-section rod 160 floating above the sorting region (128) on the rollers (112,114), so that sorting accuracy and throughput are not degraded.