Electrostatic Precipitator (ESP) Manufacturing

BCE electrostatic precipitators (ESP) are air pollution control devices which remove particulates from the air by using a high-voltage electric current to impart a negative electrical charge to the dust, which is then attracted to, and deposited on, positively charged plates in the unit.  BCE has engineered and installed electrostatic precipitators for a variety of installations and performs maintenance on existing ESPs.

The plates of ESP are cleaned by periodic or continuous rapping. Dust falls into the hopper(s) and is removed by a pneumatic conveying system.  ESP’s are primarily used to remove fly ash in coal-fired power plants, but can be used to remove dust from any application, and have also found use in the cement, chemical and paper industries.  Depending on the application, precipitators are designed for efficiencies between 90% and 99.9%. Increasing the power input generally increases the efficiency.  Particles over 1 micron can be collected with high efficiency, particularly when dust resistivity is low.  Efficiency drops off rapidly for extreme submicron particles due to Brownian motion, or random collisions of particulates with air molecules.

Dust resistivity is a major factor in collection efficiency.  The higher the resistivity, the more difficult it is for a particle to transfer its electrical charge. When a switch to low sulfur coal was made, it was discovered that many ESP’s no longer met emissions standards to the high resistivity of low sulfur coal.  This resulted in larger units to achieve the required efficiency.  To reduce resistivity, conditioning agents have been added to flue gases.  Sulfur trioxide has been used successfully with basic dusts such as fly ash and ammonia works well with acidic dusts.

Where a high efficiency can be achieved, an ESP is an attractive alternative to a fabric dust collector. Some advantages are:

  • Operating temperatures up to 800°F
  • No compressed air required
  • Infrequent maintenance (no bags to replace)
  • Lower pressure drop, therefore less power required to convey air

BCE will be happy to analyze your application with you to see whether an electrostatic precipitator in lieu of a baghouse may be advantageous.