Advanced study in solid transport: Rheological behavior of dense suspension
Abstract
The objective of the present research is to develop a basic understanding of the fundamental rheological properties of high solids concentration slurries or wet cake. A dynamic shear cell test device has been constructed and operated to measure dynamic shear stress and determine the effects of experimental parameters upon the dynamic shear stress of the materials. The solids used are glass beads and coal powders. The experimental parameters investigated are: water fraction, normal stress, speed, gap height, size, and size distribution. A statistical method is adapted to evaluate the effects of the experimental parameters. The experiments with glass beads show that the dynamic shear stress is independent of shear rate, providing the gap height is larger than about 27 times the bead diameter, but is a functional of normal stress and water fraction. The dynamic friction coefficient increases sharply as the water fraction increases up to 10 percent, and decreases gradually for water fractions greater than 10 percent. Dynamic experiments with coalwater mixtures show that the coalwater mixtures behave like the glass beads when water fraction is lower than a certain value. However, as the water fraction increases beyond that value, the coalwater mixtures display the characteristics of thixotropic fluids with shear thinning. The flow index of the coalwater mixtures is independent of normal stress, but decreases as the water fraction decreases.
 Publication:

Unknow
 Pub Date:
 October 1990
 Bibcode:
 1990asst.reptQ....K
 Keywords:

 Dynamic Loads;
 Dynamic Tests;
 Rheology;
 Shear Stress;
 Slurries;
 Solids;
 Statistical Analysis;
 Stress Analysis;
 Beads;
 Coal;
 Coefficient Of Friction;
 Glass;
 Powder (Particles);
 Size Distribution;
 Fluid Mechanics and Heat Transfer