98/01460 Quantifying pulverizer induced charge in a utility boiler: Schaefer, J. L. et al. Proc. Annu. Int. Pittsburgh Coal Conf., 1995, 12, 320–325

Abstract

A promising location for siting a dry electrostatic coal cleaning process is in the fuel delivery section of a utility power plant, immediately downstream of the coal pulverizers. The combination of turbulent particle contact, coal fracturing, dry transport gas, and higher temperatures indicate a potential for effective coal and ash mineral tribocharging. However, for an electrostatic dry coal cleaning process to be implemented effectively at a utility site, knowledge of the pulverizer induced charge is necessary. Hence, equipment was constructed and used to measure the charge imparted on coal, and potential separability, as a result of pulverization and subsequent transport to the burners of a utility boiler. The on-site measurements will be used to develop a laboratory-scale pulverized coal transport pipe for future electrostatic separator development. This paper details construction of, and results obtained from, the particle charge measurement and electrostatic separation probes. These findings will be compared to coal tribocharging results obtained in previous laboratory experiments. Finally, the possible ramifications of these findings on the design of an electrostatic dry coal cleaning process will be discussed.