Pressure losses in pneumatic transport. A model based on particlewall interactions and particle density distribution
Abstract
An experimentally verified model which calculates pressure losses originating from dilute phase pneumatic transport of coarse particles in the horizontal stationary flow regime is presented. The model is based on the balance of drag and frictional forces on particles. The particles are characterized by their terminal velocity, the particlewall sliding friction coefficient and the coefficient of restitution between particles and wall. The influence of the inhomogeneous particle distribution in the pipe is taken into account, by a particle density distribution, which resembles the barometric height formula. A Froude number, based on the mean square value of the radial particlevelocity component, is used as an empirical parameter. This number increases with increasing average air velocity, but perhaps depends on pipe diameter and solidsmass flow. The assumption of a linear relationship between the Froude number and the average air velocity provides scaling and predicting possibilities for pressure losses.
 Publication:

Ph.D. Thesis
 Pub Date:
 June 1982
 Bibcode:
 1982PhDT.........8O
 Keywords:

 Particle Density (Concentration);
 Particle Interactions;
 Pneumatic Circuits;
 Pressure Reduction;
 Wall Flow;
 Friction Drag;
 Froude Number;
 Parameterization;
 Particle Collisions;
 Pipe Flow;
 Skin Friction;
 Terminal Velocity;
 Fluid Mechanics and Heat Transfer