Which of the following has the lowest removal efficiency for particulate matter?

Explanation:

Gravitational Settling Chambers

• These are basic devices that remove particles by allowing them to settle under gravity.

• Efficiency is low, especially for fine particles (below 10 microns).

• Best suited for large, coarse particles in high-volume gas streams.

• Due to slow settling and minimal mechanical aid, they are not effective for modern air pollution control needs.

 Additional InformationCentrifugal Collectors (Cyclone Separators)

• Use centrifugal force to separate particles from gas streams.

• Moderate efficiency, especially effective for particles larger than 5 microns.

• Common in industrial pre-cleaning processes.

• Less efficient than electrostatic or fabric filters but better than gravitational chambers.

Electrostatic Precipitators (ESP)

• Use electrostatic charges to attract and capture particles.

• Highly efficient — over 99% removal for a wide range of particle sizes.

• Widely used in thermal power plants and cement industries.

Bag Filters (Fabric Filters)

• Work by filtering gas through woven or felted fabric.

• Offer very high efficiency — can remove even sub-micron particles.

• Used in chemical, pharmaceutical, and food processing industries for precise dust control.