Classification Of Instruments Used To Control Air Pollution

Different industries have varying demands when it comes to air pollution control, depending on the type of emission they produce. The following are the most common ones:
1. Electrostatic Precipitators (ESP)
  • Purpose: For the removal of fine particulate matter (PM10 and PM2.5).
  • Function: Operates by means of the attraction of electrostatic charges.
  • Application: In thermal power plants and cement industries, these are commonly used.
2. Baghouse Filters (Fabric Filters)
  • Purpose: For filtering out fine dust particles, they are 99 per cent efficient.
  • Function: Traps dust and fine particles using filter bags.
  • Application: For cement, metalworking, and pharmaceutical industries.
3. Scrubbers
Purpose: For removal of gases, vapours, powders, and chemical pollutants.
Function: Cleans air by washing with liquid (water or some other chemicals).
Types:
  • Wet Scrubbers – for use in chemical plants and oil refineries.
  • Dry scrubber for SOx and NOx emission control.
4. Cyclone Separators
  • Purpose: For large dust particles removal from industrial exhaust.
  • Function: Separates using centrifugal force.
  • Application: Food processing, woodworking, and textile industries.
5. Activated Carbon Filters
  • Purpose: For air purification from toxic gases and bad odours.
  • Function: Used for removal of volatile organic compounds (VOCs) and other harmful gases.
  • Application: Chemical and pharmaceutical industries.
6. Catalytic Converters
  • Transforms harmful gases such as carbon monoxide and nitrogen oxide to less harmful ones.
  • Commonly used in automobile and industrial exhaust systems.
  • Cuts down carbon monoxide, nitrogen oxides, and hydrocarbons.
7. Mist Collectors and Fume Extractors
  • Used to collect oil mist, smoke, and welding fumes.
  • Enhances the working environment in factories and workshops.
  • Important in the automotive industry and metal machining.
8. Odor Control Systems
  • Used in sewage treatment plants, food processing, and waste management.
  • Eliminates bad smells with advanced filters that make use of water spray.