Electrostatic Precipitator also known as ESP is the leading and most effective technology used for removing solid dust particles from industrial flue gases. The electrostatic Precipitator consists of a large steel chamber and inside the chamber, an electrode system is installed.
Gases generated due to the combustion of pulverized fuel contain solid dust particles.
When the solid particles are released through chimneys in the atmosphere without filtering, the atmosphere may get polluted to prevent environmental pollution these dust particles must be removed from gases before being released into the atmosphere. maximum efficiency of ESP is 99%.
Construction of Electrostatic Precipitator
An electrostatic Precipitator consists of a steel chamber in which collecting and emitting electrodes are installed. collecting and emitting electrodes are arranged in a parallel manner.
Negative electrodes called emitting electrodes are in form of a rod or wire and positive electrodes are in form of plates.
Emitting electrodes are connected to the negative terminal of the high-voltage DC supply and collecting electrodes are connected to the positive terminal of the dc supply which is earthed.
High voltage DC supply generated using rectifier transformer which steps up 440V AC into high voltage AC supply then using a rectifier circuit this AC high voltage is converted into high voltage DC and then applied to the collecting and emitting electrode.
Working of Electrostatic Precipitator (ESP)
The working principle of the electrostatic precipitator is quite simple. An ESP (electrostatic precipitator) uses a high voltage electrostatic field to separate dust particles from flue gases. The high dc voltage is applied to the collecting and emitting electrode.
The emitting electrodes are connected to the negative terminal of the high voltage DC supply. Collecting electrodes are connected to the positive terminal of the DC supply which is earthed.
The positive electrodes that are collecting plates are grounded to get stronger negativity in the negative electrode.
The medium between electrodes becomes highly negative and air molecules between electrodes get ionized hence more free electrons and ions are present in the medium.
When flue gases that are exhausted from the boiler pass through the collecting and emitting electrodes of the electrostatic precipitator. solid dust particles present in flue gases collide with the free electrons in the space between electrodes and get negatively charged.
The negatively charged dust particles are attracted toward the positive electrodes due to the electrostatic force of positive collecting plates.
At collecting electrodes dust particles are collected and the rapping mechanism separates accumulated dust particles from the collector plates. the particles released by the rapping mechanism are collected in the hopper and are removed by the ash handling system.