What is the mechanism by which a baghouse captures particulates?

• A. The fabric bags trap particulates as gas passes through; bags are shaken/cleaned.
• B. Electrostatic attraction to metal plates.
• C. Particulates are removed by a water spray.
• D. Particulates are burned off in a secondary furnace.

Answer: (B)

The mechanism in a baghouse is fabric filtration. Gas passes through porous bags made of fabric, and particles are captured by the fibers as they contact or are stopped by the fabric, with a dust cake forming on the surface that further traps particles. Periodic cleaning—by shaking or pulsing air to the bags—removes the collected dust into a hopper while the bags continue to operate. This is different from an electrostatic precipitator, which uses an electric field to attract particles to metal plates, or from methods like water sprays or secondary-furnace burning, which rely on other technologies.