||Charge Measurements on Individual Particles Exiting Laboratory Precipitators with Positive and Negative Corona at Various Temperatures.
McDonald, Jack R. ;
Anderson, Marlin H. ;
Mosley, Ronald B. ;
Sparks, Lesile E. ;
||Southern Research Inst., Birmingham, AL.;Industrial Environmental Research Lab., Research Triangle Park, NC.
||EPA-68-02-2610; EPA-600/J-80-091 ; IERL-RTP-P-304
Air pollution control equipment ;
Electrostatic precipitators ;
Electric charge ;
Electric corona ;
Mathematical models ;
||Some EPA libraries have a fiche copy filed under the call number shown.
The paper reports measurements of charge values on individual particles exiting three different laboratory electrostatic precipitators (ESPs) in an experimental apparatus containing a Millikan cell. Dioctylphthalate (DOP) droplets and fly ash particles were measured at temperatures from 23 to 343 C. At comparable voltages and currents for positive and negative coronas, the data show that the ratio of the values of negative-to-positive charge for radii in the range 0.6-1.3 micrometers increases from about 1 to 2 as the temperature increases from 37 to 343 C. Predictions of a mathematical model of ESP using an ionic charging theory show good agreement with all positive charging data, but show good agreement with negative charging data only at temperatures below 37 C. The differences in the measurements and the model predictions are consistent with the postulation of free electron charging at elevated temperatures in negative corona. (Copyright (c) 1980 American Institute of Physics.)