Mechanisms of Effective Coal Water Slurry Atomization

The atomization behavior of additive free coal-water slurry (CWS) of 65 percent by weight coal content is investigated and compared with water atomization. Simplified partial internal and external spray nozzles [1] have been used and the effect of swirl and the difference of the fluid properties between C W S and water are analyzed. Frauenhofer light defraction (Malvern) was applied as a diagnostic tool to measure the particle droplet size distribution at one axial and various radial locations in the sprays. Atomization air flow and slurry/water flow have been varied to identify the optimal nozzle performance point. The results show the expected strong effect of the atomization air flow on the average droplet size. The effect of swirl and the influence of the material properties on the atomization mechanisms are identified and their utilization to improve CWS-nozzle atomization is proposed