Electrostatic precipitators are composed of several rows of negative spray electrodes and positive precipitating electrodes. A DC voltage of 20-100 kV is applied between these two electrode types.
An electrostatic charge is induced in the dust particles, which then move towards the precipitating electrode where they are collected.
Electrostatic precipitators are robust, low-maintenance devices, offering high availability. Precipitator efficiencies of over 99.8 percent can be achieved with multi-zone electrostatic precipitators.
Excellent efficiency is maintained even if the proportion of solids in the flue gas stream is extraordinarily high. This is for example the case when the flue gas stream contains particles of the reaction products from a spray absorption or dust-like ashes from a steam generator.
An electrical precipitator is however not suitable for removal of gaseous pollutants.