The physics of coal liquid slurry atomization. Quarterly technical report, January 1995--March 1995

In this reporting period, the major objective of the research was to develop a technique for measuring the extensional viscosity of coal-water slurries. The Extensional properties of the suspending solutions (water + additives) and the slurries (coal + water + additives) are determined using the breakup of droplets in the drip mode. Photographic visualization of the breakup of viscoelastic materials in the drip mode has shown that these materials exhibit completely different breakup patterns when contrasted to viscoinelastic materials. The ligaments were seen to undergo a very large stretching motion before they breakup, resulting in long threads of liquid attached to droplets. The diameter of the ligaments at breakup, as measured by the Greenfield digital spray analyzer, was of the order of 30 {mu}m. The drip mode of breakup was used to extract useful information on the extensional properties of CWS