why do some factories not use electrostatic precipitators

Inside an electrostatic precipitator some of the electrodes are  made to be positively charged and some of them are made to be  negatively charged. Usually the voltage betwe
en the electrodes is  very high. When smoke or other exhaust gases are sent through the  precipitator particles in the gas with negative charges tend to go  to the positively charged electrodes and positively charged  particles go to the negatively charged electrodes.


When the  particles reach the electrodes many are neutralised and fall to the  bottom of the precipitator where they may be collected  periodically.


Some cling to the electrodes which means that  precipitators must be cleaned periodically too. Many power stations burn fossil fuels such as coal and oil. Smoke is produced when these fuels burn. Smoke comprises tiny solid particles, such as unreacted carbon, which can damage buildings and cause breathing difficulties.


To avoid this, the smoke is removed from waste gases before they pass out of the chimneys. The electrostatic precipitator is the device used in chimneys for this job. Smoke particles pick up a charge as they pass the charged metal grid. These smoke particles are attracted to oppositely charged collecting plates.


Smoke particles are attracted to the collecting plates, which are earthed or positively charged Collecting plates are knocked to remove the smoke particles, which then fall into a collector. The metal grids in the electrostatic precipitator are given a high voltage.


Depending on the design, the grids may be positively charged or negatively charged dust particles gain electrons if the grids are negatively charged. The charged dust particles then induce a charge on the earthed metal collecting plates and the dust particles are attracted to the plates.

  • Autor: telfild
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