technical seminar - 2004 presented by :- dipti ranjan khuntia (ee200117115) electrostatic...

Technical Seminar - 2004

Presented by :- Dipti Ranjan Khuntia (EE200117115)

ELECTROSTATIC PRECIPITATORS

Presented by

Dipti Ranjan Khuntia Roll # EE200117115

Under the Guidance of

Mr. GAYADHAR PANDA



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



Theory of Precipitation: Theory of PrecipitationCharging, 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



Particle Charging:



Corona Discharge



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 design

Typical rigid discharge electrode Flat-plate discharge electrode



Collection Electrodes:



High Voltage Electrical system Transformer-

rectifier (T-R) sets Primary voltmeter Primary ammeter Secondary

voltmeter Secondary

ammeter Spark meter



Rappers:

Typical hammer/anvil rappers for collection plates

Typical magnetic-impulse rappers

for collection plates



Hoppers:

Strike plates Poke holes Vibrators Rappers Hopper

Double-dump discharge device Rotary airlock discharge device



Conveyors:

Screw conveyor

Drag conveyor

Pneumatic conveyor for transporting dust from ESP



Types of Electrostatic Precipitators Tubular

Precipitators

Plate Precipitators

Gas Flow through a tubular precipitator

Gas flow through a plate precipitator



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

Cold side ESP’s



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 reentrainment 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-fuel-fired 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

technical seminar - 2004 presented by :- dipti ranjan khuntia (ee200117115) electrostatic...

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