Medium Motion Modes and Universal Curves for Gravity Separation Processes

The separation curves for gravitational separation processes have the property of affinity. This means that with a certain transformation of the coordinate axes, all experimental values of fractional extraction form a single curve in these coordinates. The ordinate values for obtaining such universal curves are called similarity criteria for separation processes. Similarity criteria have been determined for obtaining universal separation curves during separation for particles of various sizes in flows of a mobile medium for different modes: laminar, transitional and turbulent. However, it remained unclear in what limits one or another criterion should be applied in the specific conditions of separation. The article provides an analysis of the physical foundations of the interaction of a solid phase and a mobile flow in different modes of its movement. It is proven that the entire range from laminar to developed turbulent is covered by two similarity criteria.