Principally the Sieve / Mesh vibrating horizontally on a degree, carries the main material on a woven wire mesh bed using gravity while high pressure air blows through the sieves to lift the cleaning material into the air and keeping it suspended while the heavier stones etc. find their way down into a separation chamber and repelling out through a discharge chute. Heavy impurity such as stone are not lifted by the air cushion and stay on the mesh bed. The vibratory motion of the table causes the heavy impurity (stones or sand) transported to the beginning of the regulating plate at far end of the machine and that’s how a de stoner removes sand or stones from rice, grains.