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Title: Pulsed electron beam precharger. Technical progress report No. 9, September 1, 1991--November 30, 1991

Technical Report ·
DOI:https://doi.org/10.2172/10111338· OSTI ID:10111338

Quarter Nine of the Pulsed Electron Precharging project was principally devoted to reviewing and interpreting the experimental results obtained during the past eight quarters of the project. We shall first briefly review the motivation for carrying out this project and the experimental approach used. The combustion of low sulfur coal for the purpose of generating electric energy in power plants results in the production of a flue gas containing very high resistivity fly ash. This fly ash is not easily collected by conventional electrostatic precipitators due to the large electric potential difference which develops across the layer of fly ash on the collector plate. If this layer of collected material is allowed to reach a thickness as great as is nominally desirable before ``rapping`` the plates, then the collected fly ash is subject to re-entrainment into the flue gas stream due to back-corona. The back-corona corona problem is described more fully in the next section of this report. This re-entrainment problem can be eliminated through reduction of the voltage applied across the high voltage wires and the grounded plates of the electrostatic precipitator. This is not a good solution to the problem since the charging capability and collection efficiency of the precipitator system are both greatly reduced at the low voltages and resultant small corona currents required to avoid the back-corona problem. Another approach to solving the problems inherent in collecting high resistivity fly ash in an electrostatic precipitator is to decouple the charging and collecting functions. At FSU an electron beam precharger is employed directly before (upstream in the flue gas pathway) the precipitator.

Research Organization:
Florida State Univ., Tallahassee, FL (United States). Dept. of Physics
Sponsoring Organization:
USDOE, Washington, DC (United States)
DOE Contract Number:
FG22-89PC89768
OSTI ID:
10111338
Report Number(s):
DOE/PC/89768-T11; ON: DE93006135
Resource Relation:
Other Information: PBD: [1991]
Country of Publication:
United States
Language:
English