Static electricity question about factories?

Question

Why is it that the amount of smoke leaving a factory can be reduced by placing a charged object inside the chimney?

Answer 1

Companies are always trying to reduce the amount of smoke produced by chimneys and cooling towers for the benefit of the environment.

To do this they use a technique called 'Electrostatic Filtration'. The basic theory of this is the ionization of the smoke particles, this happens by passing the smoke particles through a strong electric field usually between two electrified plates. When they pass through the smoke particles are broken up into their ions with positive and negative charges. They are then attracted to the opposing charge plate. For instance a positive ion would be attracted to the negatively charged plate.

In practice a drop dray is usually suspended below the plate, so that when the current is zero the ions fall off the plates (vibration is usually required) and into the tray where they can be disposed of.

Hope this helps, obviously simplified.

Answer 2

The particulates in the smoke are attracted to the charged object and are removed from the smoke plume.