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Clean Agent System DesignClean Agent System Design
Eric Forssell and Scott HillEric Forssell and Scott Hill
Hughes Associates, Inc.Hughes Associates, Inc.
(410) 737(410) 737--86778677
www.haifire.comwww.haifire.com
NFPA World Fire Safety Congress & Expo NFPA World Fire Safety Congress & Expo
May 14, 2001May 14, 2001
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ObjectiveObjective
Discuss specific issues affecting clean agentDiscuss specific issues affecting clean agentsystem design and system reliabilitysystem design and system reliability
-- Extinguishing ConcentrationsExtinguishing Concentrations
-- Safety/Design FactorsSafety/Design Factors-- Concentration/Exposure LimitsConcentration/Exposure Limits
-- Design SoftwareDesign Software
-- Thermal DecompositionThermal Decomposition
-- Agent RetentionAgent Retention
-- Enclosure Pressure and VentingEnclosure Pressure and Venting
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What are clean agents?What are clean agents?
Definition: No residue or collateral damageDefinition: No residue or collateral damageresulting from discharge of agent.resulting from discharge of agent.
Historically: Carbon dioxide and Halon 1301 wereHistorically: Carbon dioxide and Halon 1301 were
the agents of choice. Ban on production of Halonthe agents of choice. Ban on production of Halon1301 due to contribution to stratospheric ozone1301 due to contribution to stratospheric ozone
depletion.depletion.
Current agents include a variety of halocarbon andCurrent agents include a variety of halocarbon and
inert gasesinert gases
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ApplicationsApplications
High system cost justified by high value of High system cost justified by high value of protected space or protected equipment being protected space or protected equipment being
mission/process criticalmission/process critical
Typical applications: TelecommunicationsTypical applications: TelecommunicationsEquipment, Computer/Electronics Equipment,Equipment, Computer/Electronics Equipment,
Control Rooms, Process Critical Equipment,Control Rooms, Process Critical Equipment,
Shipboard and Off Shipboard and Off --shore Machinery Roomsshore Machinery Rooms
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How do clean agents work?How do clean agents work?
Increasing the heat capacity of the fireIncreasing the heat capacity of the fireenvironment, resulting in increased amounts of environment, resulting in increased amounts of
energy required to raise the temperature of theenergy required to raise the temperature of the
incoming air to the flame temperature.incoming air to the flame temperature. Displacing oxygen, resulting in reduced heatDisplacing oxygen, resulting in reduced heat
production. production.
Undergoing endothermic (energy absorbing)Undergoing endothermic (energy absorbing)
decomposition reactions in the presence of thedecomposition reactions in the presence of the
flame.flame.
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Setting the DesignSetting the Design
ConcentrationConcentration
Establish the extinguishing concentrationEstablish the extinguishing concentration-- By test: Agent and fuel specificBy test: Agent and fuel specific
Use appropriate safety factor Use appropriate safety factor
Include any design factorsInclude any design factors
DC = (EC * SF) + DFDC = (EC * SF) + DF
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ExtinguishingExtinguishing
ConcentrationConcentration
NFPA 2001, 2000 Edition: NFPA 2001, 2000 Edition:-- Class AClass A
•• UL 2127 and UL 2166UL 2127 and UL 2166
•• Wood crib in 100 mWood crib in 100 m33 enclosureenclosure
•• Plastic fuel array in 100 mPlastic fuel array in 100 m33 enclosureenclosure
-- Class BClass B•• Cup burner Cup burner
•• Confirmed for a few fuels in larger scale tests (ULConfirmed for a few fuels in larger scale tests (UL
and IMO)and IMO)
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Class A TestsClass A Tests
UL 2127 and UL 2166UL 2127 and UL 2166-- 3 types of polymeric materials (PMMA, PP,3 types of polymeric materials (PMMA, PP,
and ABS)and ABS)
-- Difficult plastics to extinguishDifficult plastics to extinguish
-- 4 sheet array4 sheet array
-- Heptane or hot surface ignitionHeptane or hot surface ignition
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UL Class A TestUL Class A Test
ArrangementArrangement
3 0 5 m m
( 1 2 " )
8 9 m m
( 3 . 5
" )
3 0 5 m m
( 1 2 " )
951mm(37.5")
Cinder Block
PolycarbonateBaffles
Load CellDrip Tray
Channel Iron FrameCovered With SteelSheet on Top and Two Sides
AluminumAngle Frame
3.2mm (1/8") Allthread RodFuel Support
381mm (15")
254mm (10")254mm (10")
5 3 3 m m
( 2 1 " )
76mm(3")
127mm(5")
8 5 1 m m
( 3 3 . 5
" )
32mm(1¼")
LoadCell
610 mm (24")
203mm x 406mm x 9.53mm
(8" x 16" x ")Plastic Sheet
a
12mm (½")
1 2
m m
( ½ " )
Ignitor Pan
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Cup Burner ApparatusCup Burner Apparatus85 ± 2 mm85 ± 2 mm
ChimneyChimney
535 ± 25 mm535 ± 25 mm
235 mm235 mm
Diffuser Diffuser
Fuel InletFuel Inlet Air/Agent InletAir/Agent Inlet
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E ti i hi C t tiE ti i hi C t ti
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Extinguishing ConcentrationExtinguishing Concentration
Differences for HeptaneDifferences for Heptane
Agent ISO Values Other ISO Burner
Values
Difference
(%)
IG-01 (Ar) 37.5 40.8 8.8
IG-1 (N2) 33.6 30.2 11.3
IG-541 33.8 31.9, 30.6 10.4
IG-55 32.3
FC-3110 5.9 5.3 11.3
HFC-23 12 12.3 2.5
HFC-227ea 6.6 6.6 0
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Effect of RadiativeEffect of Radiative
FeedbackFeedback
rad q.
TTFF11 (Bulk)(Bulk)
rad q.
TTFF22(Bulk)(Bulk)
TTFF22> T> TFF11
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ExtinguishingExtinguishing
Concentration SummaryConcentration Summary
Extinguishing concentration determined by testExtinguishing concentration determined by test-- Variability in testingVariability in testing
Radiative feedback may affect extinguishingRadiative feedback may affect extinguishing
concentrationconcentration-- LongLong preburn preburn timestimes
-- Metal surfacesMetal surfaces
Designer must determine how hazard relates to theDesigner must determine how hazard relates to the
method for determining the extinguishingmethod for determining the extinguishing
concentrationconcentration
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Safety FactorsSafety Factors
NFPA 2001, 2000 Edition NFPA 2001, 2000 Edition-- 30%30% – – Class B, Manually activatedClass B, Manually activated
-- 20%20% – – Class AClass A
-- 10%10% – – InertingInerting
-- Design FactorsDesign Factors
ISO 14520, First Edition (August 2000):ISO 14520, First Edition (August 2000):
-- 30%30% – – Class A and BClass A and B
-- 10%10% – – InertingInerting
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Safety FactorsSafety Factors
Design deficienciesDesign deficiencies Installation deficienciesInstallation deficiencies
Uncertainty in extinguishing concentrationUncertainty in extinguishing concentration Special conditionsSpecial conditions
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Design FactorsDesign Factors
Additional quantity of agentAdditional quantity of agent Intent is to increase system reliabilityIntent is to increase system reliability
Account for specific conditionAccount for specific condition-- Number of tees Number of tees
-- Enclosure pressureEnclosure pressure
-- Unclosable openingsUnclosable openings-- Enclosure and fuel geometryEnclosure and fuel geometry
-- ObstructionsObstructions
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Prediction AccuracyPrediction Accuracy
Halocarbons (UL 2166)Halocarbons (UL 2166)
-- Mass ±10% withMass ±10% with
standard deviation lessstandard deviation less
than 5than 5
-- Discharge time ±1Discharge time ±1
secondsecond
-- Nozzle pressure ±10%
Inert Gases (UL 2127)Inert Gases (UL 2127)
-- Volume of agent ±10%Volume of agent ±10%
with standard deviationwith standard deviation
less than 5less than 5
-- Discharge time ±10Discharge time ±10
secondsseconds
-- Nozzle pressure ±10% Nozzle pressure ±10% Nozzle pressure ±10%
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Tee Design Factor Tee Design Factor
For systems protecting multiple hazardsFor systems protecting multiple hazards For each hazardFor each hazard
-- Start at point where pipe system enters theStart at point where pipe system enters the
hazard and count the number of tees in the flowhazard and count the number of tees in the flow
path back to the agent supply path back to the agent supply
-- also include any tee in the hazard that suppliesalso include any tee in the hazard that suppliesagent to another hazardagent to another hazard
-- do not include manifold teesdo not include manifold tees
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Tee Design Factor (cont.)Tee Design Factor (cont.)
Use the hazard with the highest tee countUse the hazard with the highest tee count Not necessary if system passes a discharge Not necessary if system passes a discharge
testtest
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P b bilit Di t ib ti fP b bilit Di t ib ti f
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Probability Distribution for Probability Distribution for
Agent Mass for 2 to 20 TeesAgent Mass for 2 to 20 Tees
0
2
4
6
8
10
12
14
16
18
20
22
0.60 0.65 0.70 0.75 0.80 0.85 0.90 0.95 1.00 1.05 1.10 1.15 1.20 1.25 1.30 1.35 1.40 1.45
Normalized Mass
R e l a t i v e P r o b a b i l i t y
Experiment Standard Deviat ion = 0.0304
2 Tees2 Tees
20 Tees20 Tees
4 Tees4 Tees
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Calculated Agent QuantityCalculated Agent Quantity
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Calculated Agent QuantityCalculated Agent Quantity
Probability Distribution:Probability Distribution:
A System with 8 Tees (Std. Dev. = 0.0608)A System with 8 Tees (Std. Dev. = 0.0608)
0
2
4
6
8
10
12
14
16
0.70 0.75 0.80 0.85 0.90 0.95 1.00 1.05 1.10 1.15 1.20 1.25 1.30
Measured Agent Quantity (normalized by the predicted agent quantity)
R e l a t i v e P
r o b a b i l i t y
99%
1%
WithoutWithout
Additional AgentAdditional Agent
WithWith
Additional AgentAdditional Agent
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DESIGN FACTOR
TEE COUNT
HALOCARBON
DESIGN FACTOR
INERT GAS DESIGN
FACTOR
0-4 0.00 0.00
5 0.01 0.00
6 0.02 0.00
7 0.03 0.00
8 0.04 0.00
9 0.05 0.01
10 0.06 0.01
11 0.07 0.02
12 0.07 0.02
13 0.08 0.03
Design Factor for TeesDesign Factor for Tees
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ExampleExample
Hazard 2Hazard 2
Hazard 1Hazard 1
Tee count of 8 teesTee count of 8 tees
for Hazard 2for Hazard 2 – – 4%4%
additional agentadditional agent
requiredrequired
Alternate layout toAlternate layout to
reduce tee count to 4reduce tee count to 4teestees – – no additionalno additional
agent required.agent required.
Hazard 1Hazard 1
Hazard 2Hazard 2
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Enclosure Pressure DesignEnclosure Pressure Design
Factor Factor
Agent quantity must be adjusted if ambientAgent quantity must be adjusted if ambientenclosure pressure varies by more than 11enclosure pressure varies by more than 11
percent from standard sea level pressures percent from standard sea level pressures
Pressure may be affected by factors other Pressure may be affected by factors other
than elevationthan elevation
-- Hyperbaric chambers, mines, facilities whereHyperbaric chambers, mines, facilities whereventilation fans are used to create artificiallyventilation fans are used to create artificially
higher or lower pressureshigher or lower pressures
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Additional Design FactorsAdditional Design Factors
Unclosable openingsUnclosable openings
-- Compensate by adding agent and extending dischargeCompensate by adding agent and extending discharge
timetime
Enclosure and fuel geometryEnclosure and fuel geometry-- Unusual geometries are typically addressed throughUnusual geometries are typically addressed through
nozzle placement and additional agentnozzle placement and additional agent
-- FullFull--scale machinery space tests showed that for a largescale machinery space tests showed that for a largeenclosure with a complex obstructed geometry, agentenclosure with a complex obstructed geometry, agent
concentrations varied ±20% in the enclosureconcentrations varied ±20% in the enclosure
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Additional Design FactorsAdditional Design Factors
ObstructionsObstructions-- Obstructions such as ducts, cables, lightObstructions such as ducts, cables, light
fixtures, etc. can block or impede agentfixtures, etc. can block or impede agent
discharge which can affect mixingdischarge which can affect mixing-- Address with nozzle placement and/or Address with nozzle placement and/or
additional agentadditional agent
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Concentration/ExposureConcentration/Exposure
LimitsLimits
All efforts are made to avoid anyAll efforts are made to avoid anyunnecessary exposureunnecessary exposure
-- Time delays allow for egress from areaTime delays allow for egress from area
-- Warning signals inside and outside of enclosureWarning signals inside and outside of enclosure
indicate system activationindicate system activation
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Concentration/ExposureConcentration/Exposure
LimitsLimits
For halocarbons, maximum safe exposureFor halocarbons, maximum safe exposurelimit determined by cardiac sensitizationlimit determined by cardiac sensitization
-- Determined by testing with dogs stressed withDetermined by testing with dogs stressed with
adrenalineadrenaline-- NOAEL NOAEL -- No Observable Adverse Effect Level No Observable Adverse Effect Level
-- LOAELLOAEL -- Lowest Observable Adverse Effect LevelLowest Observable Adverse Effect Level
-- PBPK PBPK -- PhysiologicallyPhysiologically--Based Pharmacokinetic, modelBased Pharmacokinetic, modelused to account for rate of uptake of agent into theused to account for rate of uptake of agent into the
blood stream blood stream
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Maximum ConcentrationsMaximum Concentrations
Normally occupied enclosures Normally occupied enclosures-- Halocarbon agentsHalocarbon agents
•• Up to NOAELUp to NOAEL
•• Up to LOAEL with means to limit exposure to timeUp to LOAEL with means to limit exposure to timelimits from PBPK modellimits from PBPK model
-- Inert gasesInert gases
•• Up to 43% (12% oxygen) with means to limitUp to 43% (12% oxygen) with means to limit
exposure to 5 minutesexposure to 5 minutes
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Maximum ConcentrationsMaximum Concentrations
Normally unoccupied enclosures Normally unoccupied enclosures-- Halocarbon agentsHalocarbon agents
•• Up to 24% (16% oxygen) with means to limitUp to 24% (16% oxygen) with means to limit
exposure to time limits from PBPK modelexposure to time limits from PBPK model
-- Inert gasesInert gases
•• Up to 52% (10% oxygen) with means to limitUp to 52% (10% oxygen) with means to limit
exposure to 3 minutesexposure to 3 minutes
•• Up to 62% (8% oxygen) with means to limitUp to 62% (8% oxygen) with means to limit
exposure to 30 secondsexposure to 30 seconds
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What is the Purpose of FlowWhat is the Purpose of Flow
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What is the Purpose of FlowWhat is the Purpose of Flow
Calculation Software?Calculation Software? Predict system discharge performance for designPredict system discharge performance for design
purposes purposes-- Discharge time, nozzle pressure, nozzle agent quantityDischarge time, nozzle pressure, nozzle agent quantity
-- Generally, systems are not discharge testedGenerally, systems are not discharge tested
Insure system meets criteriaInsure system meets criteria-- NFPA 2001, Listing or approval NFPA 2001, Listing or approval
-- AHJ, OEMAHJ, OEM
Software is a toolSoftware is a tool
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S l S tS l S t
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Sample SystemSample System
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P t ti f MiP t ti f Mi
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Protection from MisuseProtection from Misuse
Initial listing/approval and followInitial listing/approval and follow--up serviceup service
Acceptable hardware “built in”Acceptable hardware “built in” Error and Warning messagesError and Warning messages
Trained and competent user Trained and competent user Review of the designReview of the design
--
AHJ/InsuranceAHJ/Insurance
-- Owner Owner
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Additional FeaturesAdditional Features
Export pipe layout to Cad packagesExport pipe layout to Cad packages
Ability to lock diameter for individual pipeAbility to lock diameter for individual pipe
segmentssegments
-- Particularly helpful with retrofitsParticularly helpful with retrofits
Design specific helpDesign specific help
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Verification of FlowVerification of Flow
Calculation MethodCalculation Method
Series of discharge tests conducted to verifySeries of discharge tests conducted to verify
predictions predictions
Tests also establish other system limitsTests also establish other system limits
-- minimum and maximum orifice area ratiosminimum and maximum orifice area ratios-- tee types, orientations, and split ratiostee types, orientations, and split ratios
-- maximum arrival time imbalancemaximum arrival time imbalance
-- maximummaximum runoutrunout time imbalancetime imbalance
-- maximum pipe volume to agent liquid/cylinder volumemaximum pipe volume to agent liquid/cylinder volume
ratio (percent in pipe)ratio (percent in pipe)
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““PrePre--Witness” TestsWitness” Tests
3 and 4 nozzle tests3 and 4 nozzle tests
Each test with multiple limits includedEach test with multiple limits included
All limits hit at least onceAll limits hit at least once
Submittal package put together Submittal package put together
-- software outputsoftware output
-- asas-- built drawings built drawings-- experimental dataexperimental data
All tests must pass criteriaAll tests must pass criteria
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““Witness” TestsWitness” Tests
UL/FM presentUL/FM present
2 of the pre2 of the pre--witness tests chosenwitness tests chosen
-- ReRe--run the tests, results must be acceptablerun the tests, results must be acceptable
At least three new “blind” tests are runAt least three new “blind” tests are run-- The limits for a test are chosenThe limits for a test are chosen
-- The test is laid out on the computer The test is laid out on the computer -- The system is constructed and the test runThe system is constructed and the test run
-- All tests must pass criteriaAll tests must pass criteria
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Limits for a Witness TestLimits for a Witness Test
Minimum fill densityMinimum fill density
Maximum discharge timeMaximum discharge time
Maximum run out time imbalanceMaximum run out time imbalance
Minimum pipe flowrateMinimum pipe flowrate
Minimum nozzle area ratioMinimum nozzle area ratio
50:50 bull tee50:50 bull tee
85:15 side tee85:15 side tee
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P t E ti i h t
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PostPost--ExtinguishmentExtinguishment
Enclosure EnvironmentEnclosure Environment
Thermal Decomposition ProductsThermal Decomposition Products
-- For Halocarbon Agents, Halon 1301, FMFor Halocarbon Agents, Halon 1301, FM--200,200,
FEFE--25, and FE25, and FE--13, production of HF is the13, production of HF is the
primary concern. primary concern.-- For Inert Gas Agents, IGFor Inert Gas Agents, IG--100, IG100, IG--01, IG01, IG--55,55,
IGIG--541 and CO2, there are no thermal541 and CO2, there are no thermal
decomposition products formed.decomposition products formed.
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P tP t E ti i h tE ti i h t
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PostPost--ExtinguishmentExtinguishment
Enclosure EnvironmentEnclosure Environment-- Resulting TDP concentration is dependentResulting TDP concentration is dependent
upon:upon:
•• Fire Size to Enclosure Volume Ratio.Fire Size to Enclosure Volume Ratio.
•• Discharge Time.Discharge Time.•• Safety Factor (Utilizing higher than minimumSafety Factor (Utilizing higher than minimum
concentration can reduce amount formed).concentration can reduce amount formed).
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E.W.Forssell, et al, “An Evaluation of the International Maritime Organization’s Gaseous Agent Test Protocol”,
Fire Technology, 2001
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Fire Size to Room Volume Ratio (kW/m3)
0 2 4 6 8 10 12 14 16 18
H F C o n c e n t r a
t i o n ( p p m )
0
1000
2000
3000
4000
5000
6000
7000
8000
9000
10000
11000
12000
Approximate HF Production Correlation
(5%)(12 %) Ansul (12 %) NAFGT
(7%)
(8.5%) (9%)
(8.6%) K-F (8.6%) M/S-F
(8.6%) Chemetron
(3.7%)
(7.9%)
(6.2%)
(14.4%)
(6.2%)
(7.9%)
(14.4%)
(7.2%)
(13.2%)(5%)
(7.0%)
(6.0%)
(16%)
Agent
Halon 1301NAF-SIII
CEA-410
CEA-308
FM-200
FE-13
IMO Protocol (500 m3) (1.2 m
3) (28 m
3)
NASAUSCG (526 m
3)
(8.8%)
(5%)
(7.6%)
(12%)
NRC (121 m3)
gy
E n gr . S al m an
Al i S y e d
S E C- S OA ,A b h a
K S A .
P tP t E ti i h tE ti i h t
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PostPost--ExtinguishmentExtinguishment
Enclosure EnvironmentEnclosure Environment-- Primarily hazard is to personnel as equipment isPrimarily hazard is to personnel as equipment is
generally more tolerant than humans to exposuresgenerally more tolerant than humans to exposures
-- Dangerous Toxic Loading,Dangerous Toxic Loading, DTLHumanDTLHuman, representing, representing
the threshold for life threatening exposures estimatedthe threshold for life threatening exposures estimated
by by MeldrumMeldrum as 12,000as 12,000 ppm ppm--minutes or an exposure tominutes or an exposure to12001200 ppm ppm HF for 10 minutes.HF for 10 minutes.
•• MeldrumMeldrum, M., Toxicology of Substances in Relation to Major , M., Toxicology of Substances in Relation to Major
Hazards: Hydrogen Fluoride, Health and Safety ExecutiveHazards: Hydrogen Fluoride, Health and Safety Executive(HSE) Information Centre, Sheffield S37HQ, England, 1993.(HSE) Information Centre, Sheffield S37HQ, England, 1993.
-- Early detection and fast suppression key to limitingEarly detection and fast suppression key to limiting
effects.effects.
E n gr . S al m an
Al i S y e d
S E C- S OA ,A b h a
K S A .
H a z a r d a s s e s s m e n t o f H F c o n c e n t ra t io n s
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d u r in g G L C C E D P te s t in g
E x p o s u r e T im e ( m in )
0 1 0 2 0 3 0 4 0 5 0 6 0 7 0
A v e r a g e
H F C o n c e n t r a t i o n ( p p m
)
0
1 0 0 0
2 0 0 0
3 0 0 0
4 0 0 0
5 0 0 0
M a g T a p e ( c )M a g T a p e ( o )
P a p e r ( T L )
P a p e r ( B L )
C i rc u i t B o a r d
W i re / n -H e p t a n e
L C5 0
G u i n e a P ig
R a t
R a t
R a t
M o n k e y
R a t
M o u s e
E s t im a t e d L C 5 0 , M a m m a l
E s t im a te d D T L , H u m a n
[ H u g h e s A s s o c i a te s , In c . , " H a z a r d A s s e s s m e n t o f T h e r m a l D e c o m p o s i ti o n P r o d u c t s o f F M - 2 0 0T M
i n E l e c t r o n i c s a n d D a t a P r o c e s s i n g F a c i li ti e s " , H u g h e s A s s o c i a t e s , In c . , 1 9 9 5 ]
E n gr . S al m an
Al i S y e d
S E C- S OA ,A b h a
K S A .
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Agent RetentionAgent Retention Allows for time to deal with persistentAllows for time to deal with persistent
ignition sources and for hot surfaces to coolignition sources and for hot surfaces to cooldown. Particularly important whendown. Particularly important when
automatic shutdown is not part of activationautomatic shutdown is not part of activationsequence.sequence.
Common cause of discharge test failures.Common cause of discharge test failures.
No hard answer for how long is enough No hard answer for how long is enough(case by case).(case by case).
E n gr . S al m an
Al i S y e d
S E C- S OA ,
A b h a
K S A .
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Agent RetentionAgent RetentionThe time, T, for the interface to descend to anyThe time, T, for the interface to descend to any
level, H, in the enclosure, is:level, H, in the enclosure, is:
T=2AT=2Aenclencl[(K [(K 33HHenclencl))0.50.5--(K (K 33H)H)0.50.5]/K ]/K 33FFAACCDDAALeak Leak
wherewhere
K K 33=2g(p=2g(pmixmix--ppairair)/[p)/[pmixmix+p+pairair(F(FAA/(1.0/(1.0--FFAA))]))]
E n gr . S al m an
Al i S y e d
S E C- S OA ,
A b h a
K S A .
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Agent RetentionAgent Retention
Agent retention or holding time usuallyAgent retention or holding time usually
based upon final interface height equal to based upon final interface height equal to
highest (lowest for nitrogen) combustiblehighest (lowest for nitrogen) combustible
material in enclosure.material in enclosure.
E n gr . S al m an
Al i S y e d
S E C- S OA ,
A b h a
K S A .
Agent Retention Time in 10x10x10 ft Enclosure
with FA=0.5, Highest Combustible at 7.5 ft or
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g
Lowest Combustible at 2.5 ft for Nitrogen
Leakage Area (ft2)
0.00 0.25 0.50 0.75 1.00 1.25 1.50 1.75 2.00
A g e n t R e t e n t i o n T i m e ( m i n u t e s )
0
2
4
6
8
10
12
14
16
18
20 5% Halon 1301
8.7% FM-200
16.8% FE-13
11.7% FE-25
40.3% Inergen (IG-541)
54.6% Argon (IG-01)
45.5% Argonite (IG-55)
36.4% CO2
40.3% Nitrogen (IG-100)
E n gr . S al m an
Al i S y e d
S E C- S OA ,
A b h a
K S A .
Agent Retention Time in 10x10x10 ft Enclosure
with FA=0.5, Highest Combustible at 7.5 ft
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Leakage Area (ft2
)
0.0 0.1 0.2 0.3 0.4 0.5
A g e n t R e t e n
t i o n T i m e ( m i n u
t e s )
0
2
4
6
8
10
12
14
16
18
20
5% Halon 13018.7% FM-200
16.8% FE-13
11.7% FE-25
40.3% Inergen (IG-541)
54.6% Argon (IG-01)
45.5% Argonite (IG-55)
36.4% CO2
40.3% Nitrogen (IG-100)E n gr . S al m an
Al i S y e d
S E C- S OA ,
A b h a
K S A .
Enclosure Pressure andEnclosure Pressure and
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Enclosure Pressure andEnclosure Pressure and
VentingVenting
The experienced enclosure pressureThe experienced enclosure pressure
depends upon the following factors:depends upon the following factors:
-- Total leakage area.Total leakage area.
-- Design concentration.Design concentration.
-- Rate of agent addition (discharge time).Rate of agent addition (discharge time).
E n gr . S al m an
Al i S y e d
S E C- S OA ,
A b h a
K S A .
Enclosure Pressure andEnclosure Pressure and
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Enclosure Pressure andEnclosure Pressure and
VentingVenting For agents stored as a liquid, Halon 1301,For agents stored as a liquid, Halon 1301,
FMFM--200, FE200, FE--25, and FE25, and FE--13, the enclosure13, the enclosureundergoes two pressure pulses.undergoes two pressure pulses.
-- The first pulse is negative and is due to theThe first pulse is negative and is due to thequick reduction in enclosure temperaturequick reduction in enclosure temperaturecaused by the vaporization of the agent in thecaused by the vaporization of the agent in the
enclosure.enclosure.-- The second pulse is positive, caused by theThe second pulse is positive, caused by the
volume of the added agent.volume of the added agent.
E n gr . S al m an
Al i S y e d
S E C- S OA ,
A b h a
K S A .
8% FM-200TM
Discharge with 226 cm2
(35 in2) Leak in 85 m
3(3000 FT
3) Enclosure
Enclosure Pressures
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8% FM-200 Discharge with 226 cm (35 in ) Leak in 85 m (3000 FT ) Enclosure
[Great Lakes Chemical Corporation, 1997]
Cylinder Actuation
NozzleLiquidRun-Out
TotalDischarge
Time (sec)
15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
P r e
s s u r e ( i w c )
-1.50
-1.25
-1.00
-0.75
-0.50
-0.25
0.00
0.25
0.50
0.75
1.00
1.25
1.50
1.75
2.00
P r e
s s u r e ( P a )
-350
-300
-250
-200
-150
-100
-500
50
100
150
200
250
300
350
400
450
E n gr . S al m an
Al i S y e d
S E C- S OA ,
A b h a
K S A .
Leakage Area per Enclosure Volume (in2/ft
3)
0.008 0.009 0.010 0.011 0.012 0.013 0.014 0.015
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Enclosure Pressures During FM-200TM
Testing
[M. Robin, "Investigation of the Pressure Dynam ics of FM-200 System Discharges",Presented at 1997 Halon Options Technical W orking Conference, Albuquerque, NM, May 1997]
E n
c l o s u r e P r e s s u r e
( i w c )
-3.0
-2.5
-2.0
-1.5
-1.0
-0.5
0.0
0.5
1.0
1.5
2.0
2.5
3.0
E n c l o s u r e P r e s s u r e
( P a )
-700
-600
-500
-400
-300
-200
-100
0
100
200
300
400
500
600
700
Leakage Area per Enclosure Volume (cm2/m
3)
1.9 2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 2.9 3.0 3.1 3.2 3.3
7% Cinder Block
8% Cinder Block
9% Cinder Block
7% Gypsum
8% Gypsum
9% Gypsum
E n gr . S al m an
Al i S y e d
S E C- S OA ,
A b h a
K S A .
Enclosure Pressure andEnclosure Pressure and
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Enclosure Pressure andEnclosure Pressure and
VentingVenting For agents stored as a compressed vapor,For agents stored as a compressed vapor,
IGIG--01, IG01, IG--100, IG100, IG--55, IG55, IG--541, the541, the
enclosure undergoes a single pressure pulse.enclosure undergoes a single pressure pulse.
-- Maximum enclosure pressure corresponding toMaximum enclosure pressure corresponding tothe maximum rate of agent addition.the maximum rate of agent addition.
-- Easier to predict as the significance of the heatEasier to predict as the significance of the heat
transfer from the compartment boundaries istransfer from the compartment boundaries is
reduced.reduced.
E n gr . S al m an
Al i S y e d
S E C- S OA ,
A b h a
K S A .
Enclosure Pressure andEnclosure Pressure and
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Enclosure Pressure andEnclosure Pressure and
VentingVenting With detailed flow predictions andWith detailed flow predictions and
enclosure details, the experienced enclosureenclosure details, the experienced enclosure
pressure can be predicted with an pressure can be predicted with an
appropriate equation of state.appropriate equation of state.
E n gr . S al m an
Al i S y e d
S E C- S OA ,
A b h a
K S A .
System Pressures
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Time (sec)
0 20 40 60 80 100 120 140 160
P r e s s u r e ( p s i g )
0
200
400
600
800
1000
1200
1400
1600
1800
2000
2200
Exp-Manifold
Exp-Nozzle
Pred-Cylinder
Pred-Node1
Pred-Manifold
Pred-NozzleE n gr . S al m an
Al i S y e d
S E C- S OA ,
A b h a
K S A .
Enclosure Pressure
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Time (sec)
0 10 20 30 40 50 60
E n c l o s u r
e P r e s s u r e ( i w c
)
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
Measured
Predicted
E n gr . S al m an
Al i S y e d
S E C- S OA ,
A b h a
K S A .
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Enclosure Pressure andEnclosure Pressure and
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Enclosure Pressure andEnclosure Pressure and
VentingVenting Enclosure StrengthEnclosure Strength
-- Varies with type of construction, but is lessVaries with type of construction, but is less
than you might think. 2than you might think. 2 iwciwc (500 Pa) is a(500 Pa) is a
conservative value.conservative value.-- Venting is required if developed pressure isVenting is required if developed pressure is
greater than what can be tolerated.greater than what can be tolerated.
E n gr . S al m an
Al i S y e d
S E C- S OA ,
A b h a
K S A .
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SummarySummary Extinguishing concentrations are determined byExtinguishing concentrations are determined by
test and are agent and fuel specific. Need totest and are agent and fuel specific. Need tounderstand how protected hazard relates to testunderstand how protected hazard relates to test
fuels.fuels.
2000 edition of NFPA 2001 includes an increased2000 edition of NFPA 2001 includes an increased
safety factor (30%) for Class B and manuallysafety factor (30%) for Class B and manually
activated systems.activated systems. ISO 14520 requires a 30% safety factor for ClassISO 14520 requires a 30% safety factor for Class
A and B hazards.A and B hazards.
E n gr . S al m an
Al i S y e d
S E C- S OA ,
A b h a
K S A .
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SummarySummary For some systems/applications the minimumFor some systems/applications the minimum
safety factor may not be appropriate. Thesafety factor may not be appropriate. Thedesigner must understand and account for thedesigner must understand and account for theissues that affect system reliability.issues that affect system reliability.
NFPA 2001 allows halocarbon concentrations NFPA 2001 allows halocarbon concentrationsabove the NOAEL if means are provided to limitabove the NOAEL if means are provided to limitthe exposure time to those determined using thethe exposure time to those determined using the
PBPK model.PBPK model. Software that has been thoroughly tested andSoftware that has been thoroughly tested and
validated is essential.validated is essential.
E n gr . S al m an
Al i S y e d
S E C- S OA ,
A b h a
K S A .
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SummarySummary Early detection and fast suppression are the key toEarly detection and fast suppression are the key to
limiting production of thermal decompositionlimiting production of thermal decomposition products. products.
Agent retention time is dependent on agentAgent retention time is dependent on agent
concentration, total leakage area, and leak concentration, total leakage area, and leak distribution.distribution.
There is no hard answer for how long the retentionThere is no hard answer for how long the retention
time needs to be.time needs to be.
E n gr . S al m an
Al i S y e d
S E C- S OA ,A b h a
K S A .
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SummarySummary Developed enclosure pressures depend on theDeveloped enclosure pressures depend on the
agent, design concentration, leakage area, andagent, design concentration, leakage area, anddischarge time.discharge time.
Venting is required if the developed pressureVenting is required if the developed pressure
exceeds the enclosure strength.exceeds the enclosure strength.
E n gr . S al m an
Al i S y e d
S E C- S OA ,A b h a
K S A .