Application SEM to Analysis Formation Characteristic of Soot Aerosol Emitted from Lump-Coal Combustion in Fixed-Bed

The objectives of this work are to study the formation characteristic of soot aerosol derived from lump-coal combustion in different experimental conditions in fixed bed. A laboratory-scale movable-fixed bed, water-cooled soot aerosol collection system, and electric reactor have been designed and used in the process. Three kinds of coals, sized at 3-5 mm, have been heated in the experiments. The temperature and residence time of gases in hearth has been regulated. Scanning Electron Microscope (SEM) has been employed to measure shape characteristic of soot aerosol samples. The conclusions can be drawn: the diameters of soot aerosol particles are decreased by oxidation reaction with temperature increase; the diameters of soot aerosol particles are increased and the agglomeration reaction are decreased with extension of gases residence time; and more soot particles are agglomerated in high- volatile coal combustion process.