progress in rb deposit removal studieswhitty/blackliquor... · 2006-08-02 · force exerted on a...
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Progress in Recovery Boiler Progress in Recovery Boiler Deposit Removal StudiesDeposit Removal Studies
Honghi TranPulp & Paper Centre University of TorontoToronto, CANADA
The 7th International Colloquium on Black Liquor Combustion and Gasification Jyväskylä, Finland, July 31 - August 2, 2006
ResearchersResearchersFaculty
Markus BussmannDonald CormackHonghi Tran
Research StaffDr. I.M. Jameel*Dr. Andrei KaliazineDr. Morteza Eslamian
Graduate StudentsMark Martinnez*Secuk Ozcan*Resa Sabet*Kayhan Kermani*Danny Tandra*Babak EmamiAmeya Pophli
Note: * graduated or left
Fouling of Tube SurfacesFouling of Tube SurfacesFouling rate is the difference between the deposit accumulation rate (Ra) and the deposit removal rate (Rr):
Rf = Ra - Rr
Much work has been done on Ra; little has been done on Rr
Factors Affecting Deposit RemovalFactors Affecting Deposit RemovalForce exerted on the deposit the jetDeposit strengthDeposit-Jet interaction
Deposit
Nozzle
Sootblower Jet
Force
Force Exerted on a DepositForce Exerted on a DepositDepends on:
Sootblower Jet Peak impact pressure (PIP)Nozzle design, lance pressure, steam flow rateDistance between nozzle and deposit
Deposit size (thickness), shape, locationJet-deposit interaction
Jet impact angleExposure time
Deposit StrengthDeposit StrengthWhat strength?
Compressive strengthBend strength, orAdhesion strength
Difficult to reproduce the deposit-tube interfacial bond in the laboratory
Fluid Deposit Fluid Deposit -- Jet InteractionJet Interaction
BrittleFluid(Plastic)
Tube
Deposit
Interfacialbond
Jet
Before
T0
BrittleFluid(Plastic)
Tube
Deposit
Interfacialbond
Jet
After
T0
Brittle Deposit Brittle Deposit -- Jet InteractionJet Interaction
Brittle
Tube
Deposit
Interfacialbond
Jet
Before
Brittle
Tube
Interfacialbond
Jet
After
Deposit Removal by Deposit Removal by DebondingDebonding
Jet
Blow from Front(Difficult)
Deposit
Jet
Blow from Behind(Easy)
Deposit
Evidence of Evidence of DebondingDebonding
Deposit Removal Studies Using EFRDeposit Removal Studies Using EFR
Deposit compositionTube surface temperatureDeposit thicknessJet impact angle Gas/particle velocityParticle sizeSO2
1.81.61.4
1.00.80.60.40.20.0
1.2
2 10 12 14 164 6 8mole% Cl/(Na+K)
Min
imum
PIP
(MPa
)
Probe temp.=400oC0% K% CO3
Effect of Chloride on RemovalEffect of Chloride on Removal
0 mole% K/(Na+K)
5 mole%
10 mole%
20 mole%
Effect of Potassium on Deposit RemovalEffect of Potassium on Deposit Removal(5 mole% Cl/(Na+K), no CO(5 mole% Cl/(Na+K), no CO33))
Effect of SOEffect of SO22 on Removal on Removal
0.0
0.2
0.4
0.6
0.8
1.0
0 200 400 600 800 1000 1200
SO2 Conc., ppm
PIP,
MPa
600-710μ
425-600μ
300-425μ150–300μ
Correlation between PIP & SulphateCorrelation between PIP & Sulphate
0.0
0.2
0.4
0.6
0.8
1.0
20 30 40 50 60 70 80Mole% SO4/(Na2+K2)
PIP
, MP
a
600-710um
425-600um
300-425um
150-300um
Effect of Sulphate Content on Effect of Sulphate Content on TTStkStkEFR Tests, Black Liquor Particles + SO2
650
700
750
800
850
Stic
ky T
empe
ratu
re, o C
BL+SO2
650
700
750
800
850
0 20 40 60 80 1000 20 40 60 80 100mole% SO4/(Na2+K2)mole% SO4/(Na2+K2)
2
Effect of Thermal SinteringEffect of Thermal Sintering
10 20 30 40 50 600.0
0.1
0.2
0.3
0.4
0.5
0
PIP,
MPa
0.0
0.1
0.2
0.3
0.4
0.5
0 10 20 30 40 50 60Exposure Time, min.
No SO2
350 ppm SO2350 ppm SO2
ImplicationsImplicationsHigh SO2 makes deposits easier to remove, due probably to an increase in particle sticky temperatureIn a high (350 ppm) SO2 atmosphere, sulphation of carbonate reduces deposit strength with time
Effects of Probe Temperature & Effects of Probe Temperature & ClClM
inim
um P
IP (M
Pa)
1.41.2
0.8
0.60.40.2
0.0
1.0
200 300 400 500 600Probe Temperature (oC)
5 mole%Cl/(Na+K)
10 mole%Cl/(Na+K)
Economizer160-270oC: LOW
Superheater300-500oC: HIGH
Generating Bank270-300oC: MEDIUM
Tube Temperature & PIP Requirement
JetJet--DepositDeposit--Tube InteractionTube InteractionAnalysis of Sootblowing VideosCFD Modeling and Laboratory StudiesFocus on both PIP and force
DistanceJet angleOff-set
Jet Deposit
Tube
Effect of OffsetPlaten
Offset = 1.9 cm
5 cm
NozzleProbe
Jet
Platen
0
20
40
60
80
100
0 10 20 30 40X, cm
PIP
, psi
g
Predicted by CFDLib-SJT model
Experimental Data-This study
X
X/D
Platen
Offset = 1.9 cm
5 cm
NozzleProbe
Jet
Platen
0
20
40
60
80
100
0 10 20 30 40X, cm
PIP
, psi
g
Predicted by CFDLib-SJT model
Experimental Data-This study
X
Platen
Offset = 1.9 cm
5 cm
NozzleProbe
Jet
Platen
0
20
40
60
80
100
0 10 20 30 40X, cm
PIP
, psi
g
Predicted by CFDLib-SJT model
Experimental Data-This study
0
20
40
60
80
100
0 10 20 30 40X, cm
PIP
, psi
g
Predicted by CFDLib-SJT model
Experimental Data-This study
X
X/D
0.45 cm
0
20
40
60
80
100
120
0 5 10 15 20X, cm
PIP
, psi
gExperimental Data-This study
Platen
5 cm
Probe
Platen
Nozzle
Jet
X
Predicted by CFDLib-SJT model
X/D
0.45 cm0.45 cm
0
20
40
60
80
100
120
0 5 10 15 20X, cm
PIP
, psi
gExperimental Data-This study
Platen
5 cm
Probe
Platen
Nozzle
Jet
0
20
40
60
80
100
120
0 5 10 15 20X, cm
PIP
, psi
gExperimental Data-This study
0
20
40
60
80
100
120
0 5 10 15 20X, cm
PIP
, psi
gExperimental Data-This study
0
20
40
60
80
100
120
0 5 10 15 20X, cm
PIP
, psi
gExperimental Data-This study
Platen
5 cm
Probe
Platen
Nozzle
Jet
Nozzle
Jet
X
Predicted by CFDLib-SJT model
X/D
Effect of Blowing Angle
Sootblower
Xδ
R
Platen
Sootblower
-90 -60 30- 0 30 60 90
Blowing Angle δ
V (inch/s)R (inch)
40
80
120
160160
00
V
Jet between Plates: Velocity Contour
Model Deposit Removal By Air JetModel Deposit Removal By Air JetPlaster of Paris : Water = 1:1
Alstom PowerAracruz CeluloseBabcock & WilcoxBoise Paper SolutionsBowater CanadaCenibraClyde-BergemannDaishowa-MarubeniDiamond Power International
DomtarGeorgia PacificInternational PaperIrving Pulp & PaperKvaerner PulpingMeadWestvacoStora-Enso ResearchTembecVotorantim Celulose E Papel
NSERC
AcknowledgementsAcknowledgementsMembers of the Research Consortium on
Increasing Energy and Chemical Recovery in the Kraft Process
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