Dispersion of Low Density Fine Particles Falling in Still Liquid

Abstract

A model study was carried out to understand the dispersion of slag particles in the sea, which were introduced onto its surface as a nutritional source for CO₂ fixation with marine phytoplankton multiplication. A mixture of water and fine particles was introduced onto the surface of a water bath using an acrylic pipe. The fine particles were used to decrease the falling velocity to a very low level. The behavior of them in the bath was observed with a CCD camera and a high-speed video camera. They dispersed suddenly on the bath surface just after the attachment of the mixture to the bath surface due to the surface tension force. The falling patterns of them were depended on the initial concentration of the mixture and basically classified into three types. The dispersion in the horizontal direction became greatest at a certain initial concentration. An optimum initial concentration therefore exists for uniform dispersion of fine particles in the bath.