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Transcript of Kirk Richardson
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LNGLNG Vapor and Fire ControlVapor and Fire Control
Using High Expansion FoamUsing High Expansion Foam
Kirk RichardsonKirk RichardsonEmergency Services Training InstituteEmergency Services Training Institute
Texas Engineering Extension ServiceTexas Engineering Extension ServiceTexas A&M University SystemTexas A&M University System
LNGLNG Vapor and Fire ControlVapor and Fire Control
Using High Expansion FoamUsing High Expansion Foam
Vapor Control
LNGLNG Vapor and Fire ControlVapor and Fire Control
Using High Expansion FoamUsing High Expansion Foam
Fire Control
Ignition of an unconfined LNG vapor cloudIgnition of an unconfined LNG vapor cloud
Storage TemperatureStorage Temperature --260260F/F/ --162162CC
A cryogenic l iquidA cryogenic l iquid
Boiling PointBoiling Point --258F/258F/ --161161CC
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ExpansionExpansion
CoefficientCoefficient
ButaneButane 222222
PropanePropane 290290
LNGLNG 620620
NitrogenNitrogen 642642
HydrogenHydrogen 788788
Expansion RatioExpansion Ratio 620 to 1620 to 1 Burn RateBurn Rate 12.5 mm/minute12.5 mm/minute
(Steady State)(Steady State) (Gasol ine(Gasoline 4 mm/minu te)4 mm/minute)
Initial vaporization rate on waterInitial vaporization rate on water
5050 cfmcfm vapor/sq. ft.vapor/sq. ft.
Initial vaporization rate on landInitial vaporization rate on land
vaporization ratesvaporization rates
1010 cfmcfm vapor/sq. ft.vapor/sq. ft.
Steady state vaporization rateSteady state vaporization rate
11 cfmcfm vapor/sq. ft.vapor/sq. ft.
Vapor Control
Confined spill on landConfined spill on landConfined spill on landConfined spill on land
Vapor Control
Confined spill on landConfined spill on landConfined spill on landConfined spill on land
Vapor Control
1 cfm / sq ft
Confined spill on landConfined spill on landConfined spill on landConfined spill on land
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2424
Vapor Control
Confined spill on landConfined spill on landConfined spill on landConfined spill on land
Vapor Control
Confined spill on landConfined spill on landConfined spill on landConfined spill on land
Vapor Control
The Value of
Confinement
Vapor Cloud (down wind plume) CharacteristicsVapor Cloud (down wind plume) Characteristics
before concentrations fall below LFL
(5%).
Positive buoyancy
LNGLNGvaporsvaporsLNGLNGvaporsvapors
Specific gravity (gas).5539
Vapor Cloud (down wind plume) CharacteristicsVapor Cloud (down wind plume) Characteristics
Neutral buoyancy -160F/ -107C
Negative Buoyancy
LPG vaporsvapors
Always hug the ground.
LPG vaporsvapors
Always hug the ground.
-2600F
Specific gravity (gas)1.5 2.0
Foam ClassificationFoam Classification
NFPA Gaz de France
High Expansion 200:1 to 1000:1 400:1 to 1000:1
Medium Expansion 20:1 to 200:1 75:1 to 400:1
Low expansion < 20:1 < 75:1
photograph courtesy of Angus Fire / a UTC Fire & Security Company
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Foam ApplicationFoam Application
High Expansionfoam is a toolused to gaincontrol of an LNGincident
High Expansionfoam is a toolused to gaincontrol of an LNGincident
Used to controlLNG vapors
Used to controlLNG fires
Used to controlLNG vapors
Used to controlLNG fires
Sonatrach- Arziew
High expansion foam works in conjunction with passivemethods for maintaining control of an incident.High expansion foam works in conjunction with passivemethods for maintaining control of an incident.
photograph courtesy of Angus Fire / a UTC Fire & Security Company
Foam ApplicationFoam Application
High expansion foam works in conjunction with passivemethods for maintaining control of an incidentHigh expansion foam works in conjunction with passivemethods for maintaining control of an incident
photographs courtesy of Angus Fire / a UTC Fire & Security Company
Foam ApplicationFoam Application
High expansion foam works in conjunction with passivemethods for maintaining control of an incidentHigh expansion foam works in conjunction with passivemethods for maintaining control of an incident
Foam ApplicationFoam Application
High expansion foam works in conjunction with passivemethods for maintaining control of an incidentHigh expansion foam works in conjunction with passivemethods for maintaining control of an incident
Vapor Control Techniques
Spill ConfinementSpill Confinement
Water CurtainsWater Curtains
Hi Ex FoamHi Ex Foam
Vapor Control Techniques
Spill ConfinementSpill Confinement
Water CurtainsWater Curtains
Hi Ex FoamHi Ex Foam
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How Foam Works - Vapor Dispersion Allows for controlledAllows for controlled
vaporisationvaporisation
WarmsWarms vaporsvapors so they riseso they rise
Minimizes down windMinimizes down windplumeplume
Ice layer & ice tubes formIce layer & ice tubes form
Insulates LNGInsulates LNG
Regular foam topRegular foam top--upuprequiredrequired
Dynamic situation requiringDynamic situation requiringconstant monitoringconstant monitoring
graphic courtesy of Angus Fire / a UTC Fire & Security Company
Using High Expansion Foam for Vapor Control Vapor Control Techniques
LNG Pool FiresLNG Pool Fires Flame height is typicallytwo to three times thepool diameter.
Flame height is typicallytwo to three times thepool diameter.
60 ft60 ft
Pool FiresPool Fires
30 ft30 ft
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Water Application onWater Application on
a Burning Pool of LNGa Burning Pool of LNG
How Foam Works - Fire Control Foam allows controlled
LNG burn-off
Foam insulates & reducesradiation feedback to LNG
Fire intensity decreases
Ice layer & ice tubes form
Regular foam top-uprequired to maintain steadystate
Dynamic situation requiringconstant monitoring
graphic courtesy of Angus Fire / a UTC Fire & Security Company
The Use of High Expansion Foam for
Fire Control
The Use of High Expansion Foam for
Fire Contro l
The Use of High Expansion Foam for
Fire ControlFire ControlFire Control
...on a 200 m...on a 200 m22 LNG fire,LNG fire,
the foam causes thethe foam causes the
flame height to dropflame height to drop
from about 30 meters tofrom about 30 meters toabout 2 meters.about 2 meters.
-- GazGaz de Francede France
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Fire ControlFire Control
...the amount of...the amount of
radiation from a burningradiation from a burningLNG spill can beLNG spill can be
reduced by as much asreduced by as much as
95 % with some high95 % with some high
expansion foams.expansion foams.
-- American Gas AssociationAmerican Gas Association
Fire ControlFire Control
Expansion ratios and drain timesExpansion ratios and drain times
affect performance:affect performance:
Low expansion ratios will produce foamLow expansion ratios will produce foamthat is too wet (contains too much water)that is too wet (contains too much water)
this excess water will increasethis excess water will increasevaporization, hence the size of the firevaporization, hence the size of the fire
Rapid drain times will have the sameRapid drain times will have the same
effecteffect
Fire ControlFire ControlExpansion ratios and drain times affectExpansion ratios and drain times affect
performance:performance:
Higher expansion ratios will be:Higher expansion ratios will be:
drier and thus have less resistance todrier and thus have less resistance to
thermal effects (they will break down fasterthermal effects (they will break down fasterii i . i .
Expansion ratios and drain times affectExpansion ratios and drain times affect
performance:performance:
Higher expansion ratios will be moreHigher expansion ratios will be more
adversely affected by wind and thermaladversely affected by wind and thermal
updraftsupdrafts
Expansion ratios and drain times affectExpansion ratios and drain times affect
performance:performance:Just tell them you
thought it wasdisconnected.
Higher expansion ratios will be moreHigher expansion ratios will be more
adversely affected by wind and thermaladversely affected by wind and thermal
updrafts.updrafts.
Foam Expansion & Application Rates
Tests show 500:1 is optimum expansionTests show 500:1 is optimum expansion
ratio for vapour dispersion and fire controlratio for vapour dispersion and fire control
Most operators use 500:1 systemsMost operators use 500:1 systems
Practical application rates need to bePractical application rates need to be
higher than test, typicallyhigher than test, typically
higher rates give faster controlhigher rates give faster control
less risk of escalationless risk of escalation
less radiant heat damageless radiant heat damage
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Fire SuppressionUse of dry chemical:
Appl ication technique
is everything
but a higher flow rate
never hurt anything.
but a higher flow rate
never hurt anything.
LNGLNG Vapor and Fire ControlVapor and Fire Control
Using High Expansion FoamUsing High Expansion Foam
Kirk RichardsonKirk Richardson
Emergency Services Training InstituteEmergency Services Training InstituteTexas Engineering Extension ServiceTexas Engineering Extension Service
Texas A&M University SystemTexas A&M University System