ELECTROSTATIC PRECIPITATORS

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ELECTROSTATIC PRECIPITATORS
Presented by Dipti Ranjan Khuntia Roll
EE200117115 Under the Guidance of Mr. GAYADHAR
PANDA
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Introduction

• Particulate Collection Device used in industries
  to 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

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Theory of Precipitation

• Theory of Precipitation?Charging, Collecting
  Rapping
• Particle charging? Discharge Collection
  Electrodes
• Corona Discharge? Avalanche Multiplication
• Ionization of gas molecules
• Particle Charging Mechanism? Field charging,
  Diffusion charging, Electron charging
• Particle Collection
• Particle Removal

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Particle Charging
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Corona Discharge
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• Ionization of Gas Molecules
• Particle Charging?
• Field charging,
• Diffusion charging,
• Electron charging

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• Particle collection?
• Particle Removal by rapping

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Components of an Electrostatic Precipitator

• Discharge electrodes
• Collection electrodes
• High voltage electrical systems
• Rappers
• Hoppers
• Shell

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Discharge Electrodes
Typical wire discharge electrodes
Rigid frame discharge electrode design
Typical rigid discharge electrode
Flat-plate discharge electrode
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Collection Electrodes
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High Voltage Electrical system

• Transformer-rectifier (T-R) sets
• Primary voltmeter
• Primary ammeter
• Secondary voltmeter
• Secondary ammeter
• Spark meter

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Rappers

• Typical hammer/anvil rappers for collection
  plates
• Typical magnetic-impulse rappers
• for collection plates

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Hoppers

• Strike plates
• Poke holes
• Vibrators
• Rappers

Hopper
Double-dump discharge device
Rotary airlock discharge device
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Conveyors
Drag conveyor
Screw conveyor
Pneumatic conveyor for transporting dust from ESP
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Types of Electrostatic Precipitators
Gas Flow through a tubular precipitator

• Tubular Precipitators
• Plate Precipitators

Gas flow through a plate precipitator
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Cold-side ESPs
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

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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

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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
  reentrainment or with back corona

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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-fuel-fired boilers

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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

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Thank You
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