BHA Group, Inc., Kansas City, Missouri
5.1 DEVICE TYPE
Electrostatic precipitators are used for the purpose of removing dry particulate mat-
ter from gas streams. They basically apply an electrostatic charge to the particulate
and provide sufcient surface area for that particulate to migrate to the collecting
plate and be captured. The collecting plates are rapped periodically to disengage the
collected particulate into a receiving hopper.
5.2 TYPICAL APPLICATIONS AND USES
Dry electrostatic precipitators are used to remove particulate matter from ue gas
streams exiting cement kilns, utility and industrial power boilers, catalytic crack-
ers, paper mills, metals processing, glass furnaces, and a wide variety of industrial
applications (see Figure5.1).
An electrostatic precipitator is a constant pressure drop, variable emission par-
ticulate removal device offering exceptionally high particulate removal efciency.
There is a unique jargon involving electrostatic precipitators. If you contemplate
purchasing or studying the use of one, perhaps the following buzzword list will prove
helpful. It is in alphabetical order, so if you see a word that you do not understand,
just jump down the list to nd the offending word.
Air splitter switch: An air splitter switch is mounted at the high-voltage bushing
contained on the transformer rectier. The purpose of the switch is to iso-
late one of the two electrical sections served by the transformer rectier
while the other operates.
Antisneak bafe: A deector or bafe that prevents gas from bypassing the treat-
ment zone of the precipitator.
Arc: Arcs occur within the high-voltage system as a result of uncontrolled spark-
ing. If measurable current ow is detected, damage will occur to internal
Aspect ratio: The treatment length divided by treatment height. A higher number is
more favorable for collection efciency.
Back corona: Occurs in high-resistivity dust applications. As a result of the dust resis-
tivity, a voltage drop occurs across the layer of dust on the collecting plates. The
application of current to the eld builds the charge on the surface of the dust
layer until the breakdown voltage of the dust is achieved. At this point a surge