Question

1. Identify the air pollution control device shown above.
2. Explain the function of the device in reducing air pollution.
3. Describe how the device works.

Answer 1

1. The device shown is an electrostatic precipitator (ESP).
2. The primary function of an ESP is to remove fine particulate matter (such as dust, ash, and smoke) from industrial exhaust gases (flue gas) before they are released into the atmosphere. This prevents harmful pollutants from contributing to smog, respiratory issues, and environmental degradation.
3. An electrostatic precipitator operates using the following steps:
   • Charging: As dirty flue gas enters the device, it passes through an electric field created by high-voltage discharge electrodes. These electrodes give the passing dust particles a negative charge.
   • Collection: The negatively charged particles are attracted to grounded or positively charged metal collection plates. The particles stick to these plates, allowing the cleaned gas to continue toward the smokestack.
   • Removal: Periodically, the plates are vibrated or “rapped,” causing the accumulated dust to fall into the hoppers at the bottom for collection and disposal.