Pneumatic Conveying of Solids : (Part 1, On Slip Velocities and Interaction between Wall and Particles in Horizontal Lines)

Abstract

In part 1 of this series it is attempted to describe how the slip velocity in horizontal lines depends on the tube diameter and the transport air velocity, considering momentum losses by the collision of particles with the wall. The direct determination of particle velocities and velocity losses by collision is made, using a combination of a rotating shutter and photographic measurements of particle trajectories. From these results the coefficient suggested by G. Weidner is obtained and it is shown that the experimental results of other investigators can be satisfactorily described with it. It is also explained that the slip velocity becomes constant in the region of lower transport air velocities.