Saltation and Pick-up Velocities

Saltation Mechanism

Saltation and Pickup Velocities

Generalized pickup and saltation diagram

Experimental Setup for Pickup and Saltation Meausrements Control Valve Rotameter Plug Collector 3 m 1 m Pressure Regulator Plexiglas Pipe -2/4 inches Filter Air Supply

Material Pressure Feed Vacuum Feed Vacuum Feed/Rest Minimum Recommended Velocities at the Feed Point for Various Materials Material Pressure Feed Vacuum Feed Vacuum Feed/Rest m/s m/s m/s alumina 18.3 22.4 32 calcium carbonate 9.8 23.4 33.5 clay 18.3 22.4 33.5 coffee beans 15.3 17.3 22.9 corn(grits) 21.3 23.9 30.5 corn shelled 16.8 20.8 32.0 lime(hydrated) 12.2 16.3 27.5 lime(pebble) 21.3 27.0 32.0 malt 16.8 20.3 30.5 phosphate 22.9 26.0 33.5 PE pellets 21.3 22.4 24.4 Salt 25.4 28.5 36.6 Sand 33.0 34.6 38.1 Soda ash 19.8 23.4 33.6 Starch 16.8 19.8 27.5 Sugar 18.3 22.4 33.6 Wheat 16.8 20.9 32.0

Kalman et al. Generalized Velocities Pickup Velocities

Master Curve Developed for threshold superficial velocities General Expression

Archimedes Number Ar=ρ(ρp –ρ)d3 g/µ2 Ar*=KAr   Ar=ρ(ρp –ρ)d3 g/µ2 Ar*=KAr K- parameter function of specific properties affecting specific threshold velocity to modify the Archimedes number

Saltation Velocity