A method and apparatus for detecting back corona in an electrostatic precipitator

摘要

In an electrostatic precipitator for cleaning of flue gases from industrial plants, comprising one or more precipitator sections (7) powered from a separate traditional or intermittent DC high voltage supply, the back corona discharge in the dust layer precipitated during the cleaning process on the collecting plates is detected periodically by raising the precipitator current in each DC high voltage supply unitl sparkover occurs, and where, after sparkover (F) or possibly a blocking period (B) (in case of no sparkover condition), the minimum value (U_2min, U_3min) of the precipitator voltage is compared with that (U_0min) before the sparkover, the latter value being corrected by a selected detection sensitivity factor (k).