Determination of particle sedimentation rate by ultrasonic interferometry: Role of particle size,density and volume fraction |
| |
Institution: | 1. Department of Chemical Engineering and Materials Science, University of Minnesota, Twin Cities, 421 Washington Ave SE, Minneapolis, MN, USA 55455;2. Universidad de Salamanca, Departamento de IngenieríaQuímica. Pza. Caídos 1-5, 37008 Salamanca, España. |
| |
Abstract: | The sedimentation rate (SR) of non-aggregated spherical particles in suspension was determined using an ultrasonic interferometry technique (Echo-Cell); this method is based on A-mode echography and measures the rate of formation of a sediment on a solid plate during settling. The particle accumulation rate, which is related to SR, is obtained from the interference of two waves reflected by two interfaces: one between the plate and the sediment and the other between the sediment and the suspension. Studies were carried out at 25°C using latex spheres of different diameters (7 to 20 μm) and densities (1.062 to 1.190 g/cm3) suspended in distilled water at various volume fractions (1% to 5%). As anticipated by the Stokes model, linear relations were found between SR and both particle density and the square of particle radius. Experimental SR values decreased with increasing suspension particle concentration; these concentration effects were in good agreement with those predicted by the Steinour model. Our results thus serve to validate the theoretical aspects of the Echo-Cell method and suggest its usefulness as a tool for studies of RBC interaction and RBC aggregation. |
| |
Keywords: | |
本文献已被 ScienceDirect 等数据库收录! |
|