Factors affecting the electrical characteristics of electrostatic precipitators

The paper discusses some characteristics of the voltage and current flowing in an electrostatic precipitator during normal and abnormal operation. Although the waveform of the corona current in the airgap cannot be measured, it is shown that this may be calculated from the external voltage and current waveforms. For high-resistivity particulates, the current at normal operating conditions may contain a significant proportion of positive-ion current due to the effect of the back corona. This does not contribute to the particle collection, and, if excessive, it will have deleterious effects. Its presence may be detected by the discontinuity in the voltage/current characteristic. The resultant current transient due to a spark is analysed and is shown to comprise four separate components.