Effect of humidity on negative corona discharge of electrostatic precipitators

The effect of humidity on the negative corona discharge of electrostatic precipitators was experimentally and numerically studied. The current-voltage characteristics of a wire-plate electrostatic precipitator was measured over a range of temperatures and relative humidities. The inception voltage and electric field were determined based on the streamer theory. A numerical method was used to study the influence of humidity on the distributions of electric field and charge density in an electrostatic precipitator. The results showed that the inception voltage and electric field decreased with the increase of humidity. The corona current was significantly affected by the humidity. A modified Peek formula was proposed with a correction to the humidity. The corona currents calculated with the modified Peek formula were in acceptable agreement with the experimental results. The distributions of electric field and charge density were affected by the humidity and applied voltage.