COAL SLURRY COMBUSTION (CARBON)

Experimental and numerical results are presented examining the combustion of coal-slurry fuels.; The combustion characteristics of a coal slurry agglomeration with and without metallic additives were investigated. The kinetics of the C-CO(,2) reaction was re-examined since it has a significant influence upon the burning of the droplets. The inclusion of metallic additives influences the mass reduction rate in the diffusion control regime. It was found that increases in the mass reduction rate was a function of the amount of oxygen saved due to the metal involvement in the combustion process. For the kinetic controlled regime, the increase in the mass reduction rate was directly related to the amount of metallic particles present. A theoretical study focusing upon the temperatures and size history of coal slurry droplet combustion was performed. Such droplets burn in two stages: (1) the liquid component vaporizes and burns; (2) the combustion of the heavier hydrocarbons and char occurs. Details of the reactions, quenching and influence of the flow field were examined and compared with experimental data.; The agglomeration of coal-oil mixtures (COM) droplets was studied with an electron microscope after quenching free falling mono-sized droplets which pass through an electrically heated furnace. The influence of different concentrations of No.2 and No.6 on the characteristics of the agglomerate was studied and documented. A threshold concentration of heavy oil required to form a shell structure was determined.; The final portion of this study examines coal-oil-water slurries in a spray combustion configuration. The presence of the water holds the promise of internal boiling or superheating of the water within the slurry droplet. The results of these studies support the idea that such phenomena occur and induce secondary atomization via micro-explosions within the droplet.