Transcript ELECTROSTATIC PRECIPITATORS

Presented by-Deepak keshri
IEC -CET
Section-ee 1
Introduction
 Particulate Collection Device used in industries to
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minimize air pollution.
Principle of operation Electrostatic attraction.
Efficiency of 99% in many industries.
Can handle large gas volumes with a wide range of
inlet temperatures, pressures, dust volumes, and acid
gas conditions .
Can collect particles of varying sizes in dry and wet
states .
Theory of Precipitation:
 Theory of PrecipitationCharging, Collecting &
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Rapping.
Particle charging Discharge & Collection Electrodes
Corona Discharge Avalanche Multiplication
Ionization of gas molecules
Particle Collection
Particle Removal
Particle Charging
*Ionization of
Gas Molecules
*Particle
Charging
Field charging,
Diffusion
charging,
Electron
charging
*Particle
collection
*Particle
Removal by
rapping
Components of an Electrostatic
Precipitator
 Discharge electrodes
 Collection electrodes
 High voltage electrical systems
 Rappers
 Hoppers
 Shell
Discharge Electrodes:
Typical wire discharge electrodes Rigid frame discharge electrode des
Typical rigid discharge electrode
Flat-plate discharge electrod
Collection Electrodes:
High Voltage Electrical system
*Transformerrectifier (T-R) sets
*Primary voltmeter
*Primary ammeter
*Secondary
voltmeter
*Secondary ammeter
Spark meter
Rappers:
*Typical
hammer/anvil
rappers for
collection plates
*Typical magneticimpulse rappers
for collection
plates
Hoppers:
*Strike plates
*Poke holes
*Vibrators
*Rappers
Rotary airlock discharge device
Hopper
Double-dump discharge devic
Conveyors:
Drag conveyor
Pneumatic conveyor for
Screw conveyor transporting dust from
Types of Electrostatic Precipitators
*Tubular
Precipitators
*Plate Precipitators
Cold-side ESPs
Cold side ESPs
1) volume of flue
gas that is handled is
less
2) less costly
3) overall size of
the unit is smaller
4) used to remove
fly ash from boilers
that burn high sulfur
coal
Hot Side ESPs
*used in high-temperature
applications (Cement kiln)
*the gas volume treated in
the ESP is larger
*the overall size of the
precipitator is larger making
it more costly
*structural and mechanical
problems occur in the
precipitator shell
Wet Side ESPs
*Wet ESPs are used for
industrial applications
where the potential for
explosion is high .
*When dust is very sticky,
corrosive, or has very high
resistivity .
*It does not have problems
with rapping rentrainment
or with back corona .
Dry Side ESPs
*Particles are charged
and collected in a dry
state .
*Dust particles
collected are removed
by rapping.
*Used in steel
furnaces, cement
kilns and fossil-fuelfired boilers.
Conclusion
 All ESPs, no matter how they are grouped, have similar
components and operate by charging particles or
liquid aerosols, collecting them, and finally removing
them from the ESP before ultimate disposal in a
landfill or reuse in the industrial process.
 The precipitator should be designed to provide easy
access to strategic points of the collector for internal
inspection of electrode alignment, for maintenance,
and for cleaning electrodes, hoppers, and connecting
flues during outages.