Atomization behavior of composite liquid fuels based on typical coal processing wastes.

Typical coal processing wastes can be used as fuel, though of a low rank, because they contain a combustible component – coal particles, usually less than 100 μm in size. Waste-to-energy combustion is a promising way to solve a number of environmental, economic, and energy problems: low-rank coals, coal processing and petroleum refining wastes are involved in the energy sector as components of coal-water slurries with or without petrochemicals. In this research, we used state-of-the-art non-contact optical measurement techniques to experimentally study the atomization behavior of high-potential liquid fuels. The fuels were based water and a typical coal processing waste – filter cake – in the form of particles less than 100 μm in size. Following the experiments, we have established the variation ranges of the jet characteristics and the effect of spraying conditions thereon for each composition under study. For each characteristics recorded, dimensionless integral criteria have been calculated illustrating the atomization behavior. Finally, we have determined the values of the spraying efficiency factor for all the slurries under study. These values make it possible to predict the fuel atomization and ignition behavior as well as compare the fuel compositions and choose the one for specific operating conditions. [Display omitted] • Velocity and size of composite slurry droplets, and jet angle are studied. • Spraying efficiency factor is proposed accounting for the droplet sizes and velocities. • An increase in the filter cake in slurry leads to increase in the jet velocities. • An increase in the filter cake in slurry contributes increase in the droplet size. • The largest droplets are in the jet center and small ones belong on its periphery. [ABSTRACT FROM AUTHOR]