The document discusses electrostatic precipitators (ESPs), which are devices that remove dust particles from gas streams using electrostatic forces. ESPs work by charging dust particles using corona discharge and attracting them to oppositely charged collection plates. Key components of an ESP include discharge electrodes, collection electrodes, a rectifier to convert AC to DC power, and a hopper to collect dust. Factors like gas velocity, ESP geometry, and particle residence time impact collection efficiency. ESPs are highly efficient filtration devices that allow gas flow while removing fine particulate matter like dust and smoke.