ESP.ppt

ESP

1. Electrostatic Precipitator
(ESP)
Presented By:
ANJANI KUMAR PAL

2. Introduction
AnESPisadeviceforthecleaningofdustparticlesfromtheharmfulfluegasesthat
areexposedoutfromtheboilerofasteampowerplant.
(Collectdustinthefluegasproducedbyboiler.)

3. Principle
An ESP works on the principle of thecorona discharge effect. A high DC voltage is
applied across the two plates or electrodes. The negatively charged plate attracts
the dust particles which are further attracted by the positively charged electrode by
the process of Ionisation.
InSWPL,CompactElectrostaticBagPrecipitator(COEBP)isused,wherethe
ElectrostaticfieldisfollowedbybagfilterhouseintheESPassembly.
Thebagfiltersarearrangedsoastocollectasmuchamountofdustandashas
possibleonthefabric

4. Steps

5. Gas flow
Corona discharge
Collector electrode
Discharge
electrode
Steps
•Ionization of gases and charging of dust particles.
•Migration of the particle to the collector.
•Deposition of charged particles on the collecting surface.

6. Structure

7. Gas Distribution Screen
Itislocatedattheinletoftheprecipitator.Itisusedtogiveanevendistributionofgas
overprecipitatorentirecrosssectionalarea.

8. Electric field
It consist following equipment:
A.Collecting system
B.Emitting system
C.CERM
D.EERM
E.Rectifier transformer

9. Electrical Circuit Of ESP
Primaryside Voltage 415V
Primaryside Current
Secondary side voltage
Secondary side Current
<273 A
66kV
<1200 mA

10. Rapping Mechanism
Rapping mechanism is used in order to release deposited dust particles.
CERM: CERM stands for collecting electrode rapping mechanism.
It consist tumbling hammer which is
used to hammer the shock bar.
Shock bar mounted at collecting plate
lower end.
When hammer hit the shock bar dust
particles release from the collecting
plate.

11. EERM
EERM stands for emitting electrode rapping mechanism.
During ESP operation a fraction of the dust will
be collected on the emitting electrode
It is therefore necessary to rap the emitting
electrodes.
The rapping mechanism for EERM is located
on the roof.

12. Hoppers
Hopperisalargecontainerusedfordust
orashcollection.
Toensurefreeflowofashintothe
disposalsystemlowerportionsof
hoppersareprovidedwithelectrical
heaters.

13. Bag filter house
Cage of bag filter Bag filter
Purging valve or SOV Nozzle

14. ESP Control Room

15. Bypass v/v & Lifting v/v Operation
•For ASH Coating.
•Bypass v/v –Close
•Lifting v/v –Open
•For Unit Lightup.
•Bypass v/v –Open
•Lifting v/v -Close

16. Specifications in SWPL
NUMBER OF PASS PER BOILER 2
NUMBER OF FIELD IN EACH PASS 2
NUMBEROF HOPPER IN EACH PASS 6
NUMBEROF COLLECTING PLATE
IN EACH PASS
6(ROW)*25(COLUMN)
EFFICIENCY 99.9
NO. OF STUDIO 4
LIFTINGVALVE PER STUDIO 2
GD INLET TEMP FLUE GAS 125DEGREE CELC.
PULSE JETTING TIME 100-300 ms

17. Specifications in SWPL
CORONA VOLTAGE 66 kV
BAG FABRIC P84+PTFE
DIA OF ONE BAG FILTER 160 mm
NO.OF BAG FILTER 3060
COST OF EACH BAG FILTER 10,000 Rs.
LIFTING VALVE OPERATING TIME 10 sec
PURGINGHEADER PER STUDIO 2
NO. OF NOZZLE IN EACH HEADER 17
PULSEINTERVAL TIME 4-40 Sec.

18. ELECTROSTATIC PRECIPITATOR AND BAG FILTER HOUSE ELECTROSTATIC
PRECIPITATOR:
:
•Make : FUJIAN LONGKING ENVIRONMENTAL PROTECTION ENGINEERING,
•CHINA Body External size : 20450 ×19880 ×32000 mm
•Model : 2FE 280-2-1L4 x 2 x 576 -G
•Type : Horizontal double room four fields electric & bag combination type dry ash remover
•Nos. of gas path / Boiler : 2 nos
•Total Nos. of electric fields / Boiler : 2 Electric Fields
•Normal treated flue gas volume : 737214 m3 /hr
•Maximal treated flue gas volume : 838965 m3 /hr
•Effective sectional area : 279.45 m2
•Flue gas Temp. : 132 o C + 14 o C
•Inlet dust concentration : 60 gm/Nm3
•Guaranteed discharge conc. : ≤50 mg/ Nm3
•Pressure drop : ≤1200 Pa
•Velocity of FG at ESP on total area : 0.88 m/s
•Treatment time across ESP&BFH : ≥20 sec
•System Air Leakage Rate : 2%
•Guaranteed collection efficiency for design condition : 99.91 %
•Space between the centre of collecting Plates across the gas path in mm
•: Distance between the first electric field and the second electric field : 800 mm

19. TECHNICAL SPECIFICATION OF RECTIFIER TRANSFORMER
•Make : FUJIAN LONGKING ENVIRONMENT
PROTECTING COMPANY, CHINA
•Model : Step up transformer GGAJ02K-1.2A/66KV of
Field 1 & 2
•Mode : Split one-direction rectifier transformer
•AC input voltage / Current / Power : 415 V / 272 A / 113
kVA
•DC output Voltage / current / Power : 66 kV / 1.2 A / 72
kVA
•Cooling mode : Oil sink natural cooling

20. COLLECTING ELECTRODE RAPPING MECHANISM (CERM)
•Type of Speed reducer : CYCLOIDAL PIN WHEEL REDUCER
•Location : Bottom rappers
•Make : GUOMAO GUOTAI REDUCER GROUP CO. LTD, CHINA
•Model : XWED8145A-5133-0.18KW
•Nos. of CERM : 4 nos.
•Gear Ratio : 5133 : 1
•Lube oil : Gear oil 320, 1 lit per reducer
•Centre Height : 150 mm
•Motor rating : 0.18 kW
•Material of Rapping hammer : Mild Steel
•Rapping hammer weight : 8.066 kg
•Nos. of hammers on the axle : 25 Nos. per CERM

21. EMITTING ELECTRODE RAPPING MECHANISM (EERM)
•Type : Electromagnetic impulse gravity impact
rapper
•Location : Top rappers
•Nos. of EERM : 24 Nos.
•Total power at the moment of rapper : 7.5 kW

22. FILTER BAGS
•Make : Xiamen Savings Environmental Co., Ltd
•Bags Per Chamber : 374 x 4 + 391 x 4 = 3060 Nos. of
Total Bag filters
•Specification : Diam.-160 mm.
•Effective length-8060-8065 mm, Gross length-8100
mm,
•Bag Material : P84 -20% + PTFE –80%, SCRIM:
PTFE,
•Bag life : 3 year.

23. Factors affecting ESP
Performance
GasSpeed:ESPoperatesbestwithagasvelocityof1-2m/sec.
Ifspeedistoomuchhigh,particlewillnotbechargeproperly.
Ifspeedistoomuchlow,gaswillnotbedistributeproperly.
GasTemperature:Temperatureshouldabovedewpoint,belowdewpoint
condensationmayoccurandequipmentmaybedamage.
RappingFrequency:Iftherappingfrequencyreduces,thethicknessof
precipitationincreasesandhencetheeffectoffieldisreducedandsotheefficiency
ofESPreducesaswell.
ESPVoltageLevels(Coronapower):Voltageisneededtosupportanelectrical
field,whichinturntransportstheparticlestothecollectingplates.Ifvoltagereduce
particlewillnotbemigrateproperly.