EXPLOSION PROTECTION – USING THE DATABASE · 2017. 10. 22. · Constructive explosion protection...
Transcript of EXPLOSION PROTECTION – USING THE DATABASE · 2017. 10. 22. · Constructive explosion protection...
EXPLOSION PROTECTION EXPLOSION PROTECTION ––
USING THE DATABASEUSING THE DATABASE
formerly at BAM Federal Institute formerly at BAM Federal Institute for Materials Research and for Materials Research and Testing, Berlin, GermanyTesting, Berlin, Germany
Maria MolnarneMaria Molnarne
Department Department -- Chemical Safety Chemical Safety EngineeringEngineering
Database CHEMSAFE
Safety characteristics
Explosion protection
primary, secondary, tertiary (constructive) explosion protection
Examples
Summary
OutlineOutline
database for evaluated safety
characteristics of app. 3000
flammable substances: liquids,
gases, dusts and their mixtures
project partners: BAM,
DECHEMA, PTB
updated yearly ,
languages: German / English
CHEMSAFECHEMSAFE
CHEMSAFE containsCHEMSAFE contains1. Safety characteristics for fire & explosion protection,Safety characteristics for fire & explosion protection,
its definitions and information about test methodsits definitions and information about test methods
2. Occupation safety data2. Occupation safety data
3. Classification and labelling3. Classification and labelling
4. Substance identification and specifications: Synonyms,4. Substance identification and specifications: Synonyms, CASCAS--, EC, EC--, Index, Index-- and UNand UN--No., particle size distributionsNo., particle size distributions
5. References, Recommendation of experts5. References, Recommendation of experts
6. 6. Estimation methods (e.g. ISO 10156 flammability and Estimation methods (e.g. ISO 10156 flammability and oxizingoxizing potential), graphical tools, data exchangepotential), graphical tools, data exchange
Example Example -- BenzeneBenzene
Explosion region of a ternary systemExplosion region of a ternary system
Primary explosion protectionPrimary explosion protection
Explosion limits Explosion limits
Limiting values of explosion region Limiting values of explosion region (MOC, LOC, MXC, Tci), inerting(MOC, LOC, MXC, Tci), inerting
Limiting values for chemically unstableLimiting values for chemically unstable substances (maximum stability ratio)substances (maximum stability ratio)
Explosion point, Flash point Explosion point, Flash point
Safety characteristicsSafety characteristics for assessing for assessing the explosiveness (flammability) of gases & the explosiveness (flammability) of gases & liquids: liquids:
for determination of for determination of explosion limits of explosion limits of gasesgases
EN 1839EN 1839--T (tube)T (tube)
min. 100 mmmin. 100 mm
Test apparatusTest apparatus
EN 1839 EN 1839 ––B Bomb methodB Bomb method--closed vesselclosed vessel--spherical or cylindrical spherical or cylindrical --internal volume of at least 5 Liters internal volume of at least 5 Liters --spark or fusing wire igniterspark or fusing wire igniter
EN 1839 EN 1839 --T Tube methodT Tube method--open vesselopen vessel--tube (tube (
80 mm, 80 mm, minimum lengthminimum length 300 mm)300 mm)--spark igniterspark igniter
Apparatus Apparatus in EN 1839in EN 1839
Temperature influence on explosion limitsTemperature influence on explosion limits
SourceSource: : BAM, BAM, CHEMSAFECHEMSAFE
0 50 100 150 200 250 300 350 400Temperatur in oC
0
5
10
15
20
25Br
enng
asan
teil
in M
ol-%
UEG MethanOEG MethanUEG EthanOEG EthanUEG PropanOEG PropanUEG BenzenOEG Benzen
TemperatureTemperature
in in °°CC
LELLEL
UELUEL
Pressure influence on explosion limitsPressure influence on explosion limits
0,0 0,2 0,4 0,6 0,8 1,00
10
20
30
40
50
60
70
Methanol Cyclohe xan Aceton Ethanol
UEG
, O
EG
in v
ol%
p in barSourceSource: PTB, : PTB, CHEMSAFECHEMSAFE
ExplosionExplosion diagramdiagram measured data + expl. curveMOC-lineICR-lineIAR-lineSCO-line
100
100
1000
0
0
[mol %] [mol %]
[mol %]
MOC
IAR
ICR
SCOMXCA
MAI
UEL
LEL
flammable gas
inert gas
oxygen
explosion-range
withwith limiting limiting valuesvalues
MXC MXC (Tc(Tcii ))
MOC MOC (LOC)(LOC)
ExplosionExplosion
10
10
10
20
20
20
30
30
30
40
40
40
5050
50
60
60
60
70
70
70
80
80
80
90
90
90
100
100
1000
0
0
in Mol-% in Mol-%
in Mol-%
Brenngas Inertgas
Oxidator
ExplosionsbereichMXC
MOC
MAI
IAR
ICRC
Total inerting Total inerting area (areaarea (area under under LEL and ICRLEL and ICR-- line) line)
Other areas Other areas outside outside explosion explosion region are region are partially partially inertedinerted..
InertingInerting
ExplosionExplosion
Explosion region: Ethylene oxide/NExplosion region: Ethylene oxide/N22 /air/air
OHCOOOHC 22242 2225
Initial conditions:Initial conditions:100 100 °°C,C, 40 kPa40 kPa
Test method:Test method:EN 1839EN 1839--BB
ExplosionExplosion
explosive explosive without airwithout air
CombustionCombustion
DecompositionDecomposition
CombustionCombustion442 CHCOOHC
DecompositionDecomposition
Explosion region of the system Explosion region of the system Ethene/HEthene/H22 O/air at different temperaturesO/air at different temperatures
Explosion region of the ternary system Explosion region of the ternary system CHCH44 /N/N22 /air at 10 bar and 100 bar /air at 10 bar and 100 bar
chlorinenitrous oxidenitric oxideairnitrogen trifluoride
10
10
10
20
20
20
30
30
30
40
40
40
5050
50
60
60
60
70
70
70
80
80
80
90
90
90
100
100
1000
0
0
ethane nitrogen
oxidiser
oxidiser
in mol% in mol%
in mol%
Explosion region of ethane/NExplosion region of ethane/N22 with with different oxidizing gasesdifferent oxidizing gases
NN22oxidizing gasoxidizing gas
ethaneethane
CalculationCalculation methodmethod forfor flammabilityflammability (ISO 10156)(ISO 10156)
n
1i
m
1jjj
ii KB1
Tc100A
If this condition fulfilled – the mixture is classified as nonnon--flammableflammable
Flammable component
Inert component
0 10 20 30 40 50 60 70 80 90 100nitrogen in mol %
0
2
4
6
8
10
12
14
16
18
20
met
hane
in m
ol %
Explosion range methane/nitrogen/airmeasurement by Schulz BAM Lab. II.22 (1996)
LEL : 4.2 mol %LEL : 4.2 mol %UEL : 16.3 mol %UEL : 16.3 mol %TCi : 8.49 mol %TCi : 8.49 mol %
Tci-valueTci-value
0 % air0 % air
explosion rangeexplosion range
Determination of TcDetermination of Tc i i from from xx--yy diagramdiagram
Tci Tci (ISO)(ISO)
Tci Tci (BAM)(BAM)
= 8.4 = 8.4 mol%mol%
ISO 10156 (1996) Tci value for methane was 14.3 mol in %ISO 10156 (1996) Tci value for methane was 14.3 mol in %
Acetylene Acetylene –– Chemically unstable gasChemically unstable gas
Stability pressure limits for acetylene Stability pressure limits for acetylene with other gaseswith other gases
0 10 20 30 40 50 60 70 80 90 100Stoffmengenanteil Acetylen in %
0
5
10
15
20
Stab
ilität
sgre
nzdr
uck
in b
ar
WasserstoffStickstoffMethanPropan
H2N2 CH4
C3H8
Ignition energy: 70 WsIgnition energy: 70 Ws
Acetylene in mol%Acetylene in mol%
Stability
Stability pressure
pressure limit in bar
limit in bar
DustDust explosionexplosion accidentaccidentFebruaryFebruary 8, 20088, 2008 SugarSugar factoryfactorySavannahSavannah, , Georgia, USAGeorgia, USA
11-- cubic meter vessel cubic meter vessel
2020--literliter spheresphere
Dust explosion test in BAMDust explosion test in BAM
Search for sugar in CHEMSAFESearch for sugar in CHEMSAFE
Secondary explosion protectionSecondary explosion protection
Autoignition temperature of gases &Autoignition temperature of gases & vapors vapors
Minimum ignition temperatures ofMinimum ignition temperatures of dusts (clouds, layer, heaps)dusts (clouds, layer, heaps)
Minimum ignition energyMinimum ignition energy
Safety characteristicsSafety characteristics to assess to assess the ignitability of substances the ignitability of substances
Autoignition temperatureAutoignition temperature
0 2 4 6 8 10 12 14 16200
250
300
350
400
450
500
T2T3
T1T2
Methylacetat Ethylacetate Propylacetate Butylacetate Pentylacetate
Tz
in
°C
p in bar
of of flammable flammable liquids in liquids in function offunction of pressurepressure
(autoclave)(autoclave)
Quelle: PTB, Quelle: PTB, CHEMSAFECHEMSAFE
Constructive explosion protectionConstructive explosion protection
Maximum explosion pressureMaximum explosion pressure Maximum rate of pressure rise Maximum rate of pressure rise ((dp/dt)dp/dt)maxmax
KKGG value for gases and vapors: value for gases and vapors: KG -value = (dp/dt)max * V 1/3 (cubic law)
KKstst value for dust, Dust explosion classvalue for dust, Dust explosion class Maximum experimental safe gapMaximum experimental safe gap
Safety characteristicsSafety characteristics to assess to assess the severity of an explosion the severity of an explosion
5050--liter spherical liter spherical autoclave designed for autoclave designed for pressures up to 1.100 pressures up to 1.100 barbar in BAMin BAM
Investigation of detonation phenomenaInvestigation of detonation phenomena
Constructive explosion protectionConstructive explosion protection
Explosion pressure in function of Explosion pressure in function of concentration of methane in airconcentration of methane in air
0,00
1,00
2,00
3,00
4,00
5,00
6,00
7,00
8,00
9,00
3,00 5,00 7,00 9,00 11,00 13,00 15,00 17,00 19,00
CH4 [mol-%]
pex /
pi [-
]
TUD 20 °C
TUD 100 °C
TUD 120 °C
TUD 200 °C
TUD 240 °C
Data from SAFEKINEX EUData from SAFEKINEX EU--Project, TU Delft, NLProject, TU Delft, NL-- CHEMSAFECHEMSAFE
KKG G valuesvalues in functions of the test vessel in functions of the test vessel and the hydrogen composition in airand the hydrogen composition in air
0
200
400
600
800
1000
1200
0,00 10,00 20,00 30,00 40,00 50,00 60,00 70,00 80,00 90,00
H2 [mol-%]
KG
[bar
m/s
]
BAM 2.8-dm 3̂BAM 6.0-dm 3̂BAM 14.0-dm 3̂
Data from SAFEKINEX EUData from SAFEKINEX EU--Project, CHEMSAFEProject, CHEMSAFE
Experimental setup (IEC 60079Experimental setup (IEC 60079--11--1)1)
Inner (1) and outer (2) Inner (1) and outer (2) volume is filled with the same volume is filled with the same flammable mixture. flammable mixture.
Concentration of the Concentration of the flammable flammable mmixture is varied ixture is varied
Width of the gap (3) is varied Width of the gap (3) is varied by turning the screw (6)by turning the screw (6)
Ignition occurs in the centre of Ignition occurs in the centre of the inner volume; Power of the inner volume; Power of the ignition source (5) is the ignition source (5) is about 10 J about 10 J
Criterion: flame transmission Criterion: flame transmission through the gap observed through the gap observed through window (4)through window (4)
maximum experimental safe gap (MESG)maximum experimental safe gap (MESG)
Determination and estimation of MESG Determination and estimation of MESG of mixturesof mixtures
Only a few Only a few MESG MESG of mixtures are experimentally of mixtures are experimentally determineddetermined
MESG determination is time consumingMESG determination is time consuming
Using the lowest MESG of the mixtureUsing the lowest MESG of the mixture components rises often technical problemscomponents rises often technical problems
Based on some 150 measurements of differentBased on some 150 measurements of different mixtures an estimation method was developedmixtures an estimation method was developed
0,00 0,25 0,50 0,75 1,000,0
0,2
0,4
0,6
0,8
1,0
1,2
measured at 120 °C estimated measured at 40 °C estimated
MES
G
in m
m
Relative molar amount CH4
0,0
0,2
0,4
0,6
0,8
1,0
1,2Lines mean linear interpolations at 40 Lines mean linear interpolations at 40 °°C and 120 C and 120 °°CC
Mixture of methane and dioxaneMixture of methane and dioxane
MESG MESG -- measuredmeasured and estimatedand estimated
Minimum ignition energy Minimum ignition energy
maximum maximum experimental safe gapexperimental safe gap
SubstanceSubstance MIE in mJMIE in mJ MESG in mmMESG in mm
HydrogenHydrogen 0.0170.017 0.290.29
AcetyleneAcetylene 0.0190.019 0.370.37
Diethyl etherDiethyl ether 0.190.19 0.870.87
PropanePropane 0.240.24 0.920.92
MethaneMethane 0.290.29 1.141.14
AmmoniaAmmonia 1414 3.183.18
Safety characteristics of hazardous substances Safety characteristics of hazardous substances needed under process conditions needed under process conditions
Chemically unstable gases represent furtherChemically unstable gases represent further difficulties by explosion protectiondifficulties by explosion protection
Dust explosion data are needed Dust explosion data are needed with particle size distribution with particle size distribution
CHEMSAFE contains this information and CHEMSAFE contains this information and data data evaluation is given by experts evaluation is given by experts
SummarySummary
The author would like to thank Dr. M. Sam Mannan, Director of the Mary O’Connor Process Safety Center for the financial support of this presentation and BAM for the presentation materials.
AcknowledgementAcknowledgement
Thank you for attention!Thank you for attention!
BAM Test Site Technical Safety BAM Test Site Technical Safety
Limiting values of flammable mixtureLimiting values of flammable mixture
LEL lower explosion limits (mol%)
UEL upper explosion limits (mol%)
MAI minimum required amount of inert gas in inert gas-oxidizer mixtures (mol%)
MXC maximum permissible amount of flammable gas in inert gas-flammable gas mixture in mol% (if nitrogen then Tci)
MOC maximum (permissible) oxidizing gas content in mol% (if air then LOC)
SCO stoichiometric concentration for the oxidizing reaction (mol%)
ICR minimum inert gas-combustible ratio (-)
IAR minimum inert gas/oxidizer (air) ratio (-)