Abstract
Experiments on the displacement type washing in the beds packed with the solids of glass beads or crushed quartz were carried out. On the assumtion that the displacement type washing proceeds only within the saturation zone in the gravitatitationally drained bed, the author made an analyis on the residence time curve in the washing, using the mean residence time based on the volume of initial residual solution in the bed.
In general, most of the experimental data coincided with each of those residence time curves mainly characterized by the size of the packed solids. By using the modified equation of residence time curve, the apparent axial dispersion coefficient in the displacement type washing was estimated from the experimental curve.
As the result, the relation between Péclet number and Reynolds number was given in the range of Reynolds number from 10-2 to 101, as follows.
NPe=0.435(NRe)-0.075
