HYDRAULIC AND PNEUMATIC CLASSIFICATION

1. HYDRAULIC AND PNEUMATIC CLASSIFICATION

2. Main parameter - velocity of settling of particles Fc + Fo + Fb = 0 Fc - gravity force of particle in liquid Fo - resistance force Fb - inertia force

3. Fc = Vd g Fo = 0,5 c v2A Fb = Vd(d + ad c) dv/dt • A – area of projection of the maximum cross section of • the falling object perpendicularly to its movement, m2 • Vd – particle volume, m3 • ad – acceleration coefficient (dimensionless) (0,5 for • spheres, 0.75 for discs) • t – time, s • g – acceleration due to gravity, m/s2 • -friction coefficient • d - particle diameter • - particle density in medium • c - medium density • d - particle density • v - velocity of settling Terminal settling velocity 

4. or 4/3Ar =  Re2 because c - viscosity of liquid

6. spherical particles Stokes range: Re < 0.2, from ~ 0.01mm to ~0.1mm Allen’s range: 0.2<Re < 5x102, from ~0.1mm to ~1mm Newton’s range: 5x102 <Re < 3x105, above ~1mm -particle density in water, -viscosity, d-particle diameter, g-gravity constant, k - a constant, c -liquid density

7. Modes of hydraulic classication: - stationary - horizontal - vertical - pulsation - spiral

8. cone classifier

9. elutriator

10. pocket classifier

11. plunger jig

12. hydrocyclone