PREDICTING THE DEPOSIT VELOCITY FOR HORIZONTAL TURBULENT PIPE-FLOW OF SLURRIES

The sliding bed theory of deposition recently developed by Wilson and others has been compared with a range of experimental results most of them not previously published. This comparison has confirmed the suitability of this theory for the claimed range of particle sizes for solids suspended in water. However, the results for higher viscosity fluids do not show such good agreement. This disparity is later explained following the development of a theory of deposition, based on the sliding bed concept, for very fine particles smaller than the thickness of the viscous sub-layer. Furthermore, by adding the contributions of both Wilson's theory and the viscous sub-layer theory an equation is obtained which describes deposition for particles in the transition region between the two types of deposition. The two theories combined now cover the complete particle size range for unflocculated particles. In the case of flocculated particles the new viscous sub-layer theory is shown to be consistent with experimental data providing the particle properties are used instead of the floc properties. © 1979.