Combusting and Gasification Using Discrete Phase Method Combustion Through a Chamber.
Red Hot Video of Combusting Liquor & Smelt at Primary Airports · Red Hot Video of Combusting...
Transcript of Red Hot Video of Combusting Liquor & Smelt at Primary Airports · Red Hot Video of Combusting...
© 2003 Paprican 1
Red Hot VideoRed Hot Videoof Combusting Liquor & Smeltof Combusting Liquor & Smelt
at Primary Airportsat Primary Airports
Black Liquor Colloquium - Utah
Laurie FrederickDoug SingbeilJoey Kish
13 May 2003
Black Liquor Colloquium - Utah
Laurie FrederickDoug SingbeilJoey Kish
13 May 2003
© 2003 Paprican 2
• Observations– Lifespan of a Combusting
Particle
– Coating of Tubes
– Two Steady States
• Activity not causing >500°C excursions
OverviewOverview
Red (& White) Hot Video
• Background to Boiler Video Camera Probe
© 2003 Paprican 3
• Cracking of composite tubes at primary airports
• Associated with temperature excursions & cycling
• Cause of high temperatures - Unknown
• Since Feb.2001: Five successful camera probe variations
• ~ 35+ hours Video from
5 trips to 3 mills
• One design selected:
“Boiler View”
Why Build a Camera Probe?Why Build a Camera Probe?
TC1 TC2
© 2003 Paprican 4
Stage & Temperatures
(°C) Droplets PAPRICAN’S
OBSERVATIONS Eg.
Drying <= 300
Droplets swell ~1.5x ?
Devolatilization 300 > 800
Puffs up, bright yellow flame
produced Gray and Swelling
Char Burning 800 > 1200
Particle shrinks, mainly
C & Na salts
Hollow – White: Large or Medium reducing to
Solid – White: Small or Tiny
Smelt Molten Salts - C depleted
Clear Liquid or
Clear with fine black particles
Black Liquor Life SpanBlack Liquor Life SpanHupa & Frederick 1987Hupa & Frederick 1987
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BoilerBoiler--View Clip: Swelling ParticlesView Clip: Swelling Particles
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BoilerBoiler--View clip: Medium to Large ParticlesView clip: Medium to Large Particles
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BoilerBoiler--View clip: Small to Tiny ParticlesView clip: Small to Tiny Particles
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Is there something on the tubes?Is there something on the tubes?• Yes - all fireside tube surfaces are coated• ~ 2 mm thick below 1° and fairly uniform• Coating either ductile or brittle
TC2TC1
@ Shutdown Burning Oil
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Recognition of Two Steady StatesRecognition of Two Steady States• Expanded time
scale revealed two dominant temperatures
• Video revealed two associated physical states: – Coated– Protected
300
350
400
450
500
11:00 12:00 13:00 14:00 15:00 16:00
Tem
pera
ture
( °C
)
TC1
300
350
400
450
500
13:10 14:10Time
Tem
pera
ture
( °C
) TC1
300
350
400
450
500
0:00 8:00 16:00 0:00
Tem
pera
ture
( °C
) TC1TC2
24 hr
5 hr
1 hr
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Coated Steady State Coated Steady State ( CSS )( CSS )
Very Few Particles & Bed Low:• Tubes coated in a uniform “white” layer
• Temperatures on tube bends steady ( + 1 - 3°C )
• Range 390° - 410°C; Average may drift over hours
• May have clear liquid flow over surface
• Example Video:
Baseline
300
350
400
450
500
15:15 15:30 15:45
LH25-1
LH25-2
© 2003 Paprican 11
BoilerBoiler--View clip: Coated Steady StateView clip: Coated Steady State
© 2003 Paprican 12
Protected Steady State Protected Steady State ( PSS )( PSS )
Char Bed Particulate Covering Tube Bends:• Temperature steady @~320°C• High stable bed of compact particulate over coated
thermocouples• Particulate excluding radiation & atmosphere• Example Video:
High Bed
300
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450
500
10:35 10:50 11:05
RH25-1
RH25-2
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BoilerBoiler--View clip: Protected Steady StateView clip: Protected Steady State
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What Seems to Protect ThermocouplesWhat Seems to Protect Thermocouplesfrom Radiation and Atmosphere ?from Radiation and Atmosphere ?
• Some protection provided by coating on tubes• Most Effective Protection:
– A high compact bed of particles, usually grey, over coating
=> “Char Bed” Protected Steady State (PSS)
• Two Other Conditions Approach PSS:– Sticky grey particles forming a layer over coating on tubes,
above bed level– A buildup of fine black particles, produced as particles melt,
washed down the tubes and deposited by liquid at bed interface
© 2003 Paprican 15
Char Particles
Cross Section at Thermocouple (TC)Cross Section at Thermocouple (TC)
TC
TC Shield
Tube Wall Coating
Char Bed
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What Items What Items Are Not the Sole CauseAre Not the Sole Causeof > 500°C on tube bends?of > 500°C on tube bends?
• Medium to tiny white particles landing
• Surface washed with liquid or left dry
• Bed surface rising & lowering
• Darkening surface deposits
• Primary or Secondary port rodding
© 2003 Paprican 18
SummarySummary• Tubes are normally coated on the fireside with a thin,
adherent, white coating• Protection of the coated tubes from radiation and
atmosphere, may occur 3 ways:– High compact char bed against the wall (most effective)– Sticky particle layer on the tube surface, above the char bed– “Black fines” deposited to form a smooth dense dark layer
• When the Bed was low, and the thermocouples not impacted by particulate, no temperatures above 500°C were noted