What is ESP in air pollution?
Description. An electrostatic precipitator (ESP) removes particles from a gas stream by using electrical energy to charge particles either positively or negatively. Discharge electrodes are energized by a single transformer-rectifier (T-R) set power supply.
How does ESP work in power plant?
An ESP works because of electrostatic attraction (like charges repel; unlike charges attract). An ESP uses a high voltage electrostatic field to separate dust, fume or mist from a gas stream. A high voltage system provides power to the discharge electrode to generate an electrical field.
What is electrostatic precipitator used for?
Originally designed for recovery of valuable industrial-process materials, electrostatic precipitators are used for air pollution control, particularly for removing harmful particulate matter from waste gases at industrial facilities and power-generating stations.
What are the types of electrostatic precipitator?
There are four basic types of ESPs: plate and wire (dry), flat plate (dry), wet, and two-stage. ESPs provide a large air volume, operate favourably in various temperatures, and require little maintenance.
What is corona effect in ESP?
Fly ash resistivity plays a key role in dust-layer breakdown and the ESP performance. Back corona, the migration of positive ions generated in the fly ash layer toward the emitting electrodes, which neutralizes the negatively charged particles, will result if the ash resistivity is greater than 1012 ohm-cm.
What are the advantages of ESP?
Advantages of electrostatic precipitator:
- The durability of the ESP is high.
- It can be used for the collection of both dry and wet impurities.
- It has low operating costs.
- The collection efficiency of the device is high even for small particles.
- It can handle large gas volumes and heavy dust loads at low pressures.
What is corona power in ESP?
Corona power ratio is the ratio of power consumed in watts to the airflow in cubic feet per minute. This tells us about the energy consumed in filtering one cubic foot of air per minute. The corona power ratio affects the efficiency of an electrostatic precipitator.
Is lightning a corona discharge?
Corona effect, also known as corona discharge, is primarily a high-voltage transmission line phenomenon, but it is also seen surrounding lightning rods.
Why is corona discharge purple?
The bluish-purple glow that corona discharges produce is a side effect of electrons recombining with positive ions to reform neutral atoms. When atoms reform they release a photon of light. These photons ionize more atoms maintaining the corona discharge. Corona discharges are a non-thermal, non-equilibrium product.
What is the disadvantage of ESP?
Electrostatic precipitators have a high initial capital cost, which makes it prohibitive for small-scale industries. An electrostatic precipitator can be used for collecting only dry and wet pollutants and not for gaseous pollutants. This is a major disadvantage of ESPs.
What are the advantages and disadvantages of ESP?
Electrostatic Precipitators Information
| Advantages | Disadvantages |
|---|---|
| Very high collection efficiencies, even for very small particles. | Cannot control gaseous emissions |
| Can handle corrosive materials, wet materials, and high temperatures. | Very dependent on the electrical resistivity of the particulate. |
What is electric corona?
Corona is a phenomenon associated with all transmission lines. Under certain conditions, the localized electric field near energized components and conductors can produce a tiny electric discharge or corona, that causes the surrounding air molecules to ionize, or undergo a slight localized change of electric charge.