Electrostatic precipitator

Electrostatic precipitator, device that removes smoke and other particles from industrial fumes. The fumes pass through a chamber that is hung with steel tubes or plates, within or between which are suspended thin rods. A high-voltage current is fed to the rods, producing a negative charge on the particles in the fumes. The particles are then attracted by electric forces to the plates and precipitated from the fumes. The plates are shaken or knocked to dislodge the resulting deposits, which fall into a hopper and are removed. Up to 97% of particles in fumes can be captured in a precipitator. Frederick G. Cottrell built the first practical precipitator in 1904.