Under vibration, particles of different sizes segregate (Brazil nut effect). Vibration lifts and segregates particles on the inclined screen. When vibration amplitude is within the range of 3 to 3.5mm, the equipment segregates the large and small particles with best efficiency. If the amplitude is too high, the contact area between particles and screen surface is reduced and energy is wasted; if too low, particles block the aperture, causing poor separation.