In this cleaner, the coal is fed from a raw coal hopper by an oscillating plunger feeder ensuring uniform feed throughout the entire width of the machine deck. A rotating shutter in the inlet duct provides a pulsating air current, which is much more effective as a separating current than a uniform airstream. The coal and refuse stratify as they move toward the discharge end of the deck with the refuse falling to the bottom against the deck. The perforated deck has four refuse draws; normally the products of the first two draws are discharged as refuse and the third and fourth draws as middlings. The product of the third draw may be refuse or middlings, depending on the ash content of the feed. Generally, this cleaner is an effective machine for cleaning coal from 3/4 in (1.91 cm) to 1/4 in (0.64 cm) by 28 mesh if it contains less than 5% of surface moisture. It will not clean effectively below 20 mesh.