The two fundamental operations involved in electrostatic precipitation are: 1) electrical charging of the particles; 2) drift of the charged particles to the collector electrode under the influence of an electric field.

Figure 5.8 : Single stage electrostatic precipitator

 

In the electrostatic precipitator, the electric field distribution in the inter electrode space is not uniform. In a wire and tube electrode system, it varies from a high value at the wire to a low value the tube surface. In this region suitable potential difference between such electrode results in electric break down of the gas close to the high electric field strength. A blue glow develops surroundings the wire which constitutes a corona, necessary for the operation of precipitator. A steady corona needs to be maintained for successful operation.