Screening method just can separate impurities which have different granularity with grains, but is difficult to have effect for those impurities with similar granularity with grains. But these impurities have obvious difference in density, surface condition, suspension speed and settling speed. Therefore, bean cleaning machine gravity selection method is more useful.


BEAN CLEANING MACHINE GRAVITY SELECTION has dry method and wet method. Wet method uses water as the medium and removes the impurities by utilizing the different density and settling speed in water between grains and dinas. Dry method uses air as the medium and separates the impurities by utilizing the different density, surface condition and suspension speed. The common method is dry method and the equipment used in gravity selection is gravity destoner machine and gravity separating machine.

Bean cleaning machine gravity selection has its own working principle. Material can be graded automatically when it is in double vibrations. Then the material with big density, smooth surface and small granularity sinks on the sublayer. And the material with small density, coarse surface and large granularity floats on the upper layer. If there has auxiliary air flow effect, then it will have suspension or half-suspension condition(such as destoner machine, but gravity separating machine does not need air flow). With material continuous flowing in, the upper layer grains flows to the lower discharging port along with the inclining surface under the effect of reverse vibration, its own gravity and the squeezing force in material feeding. And the material which lowers at the bottom moves to the upper discharging port to realize material separating.