S+S has solved this problem for such materials as granulates or pellets

using the new modular SPEKTRUM G sorting system eliminating all the

problems of material and chute feeding. From specifically matched

vibratory feeders the material to be examined passes to a high-speed conveyor

belt, which ensures homogeneous distribution over the total belt

width. Immediately after this infeed conveyor material is optically

inspected in free fall by high-speed cameras mounted above the bulk

material. After optical categorisation, high-speed air valves are precisely

activated deflect the particles to be separated from their original parabolic

fall curve into a separate outlet chute. The SPEKTRUM G obviates the

need for channels since there is no lateral movement between detection

and separation. Friction has no effect in this free-fall inspection, resulting

in a much more accurate ejection process.