Upload
others
View
19
Download
0
Embed Size (px)
Citation preview
Fire Testing of Experimental
Siloxane-Based AFFF
Results from New Experiments
SupDet 2015
03.-06.03.2015
Ralf Hetzer2
05.03.2015
AFFF
AFFF = Aqueous Film Forming Foam
Ralf Hetzer3
05.03.2015
The Aqueous Film
The Aqueous Film…
• cools the fuel surface
• acts as vapor barrier
• operates in areas without foam
• autonomously closes
perforations of the foam
• works as buffer between fire
and foam
AFFF is the most effective agent
for pool fires!
Ralf Hetzer4
05.03.2015
Environmental Problems
Environmental Problems of AFFF:
- AFFF use PFC (polyfluorinated
compounds) to establish the water
film.
- PFC are persistent.
- PFC are strictly regulated in Germany.
Quelle: www.derwesten-recherche.org, abgerufen am 21.05.14.
Ralf Hetzer5
05.03.2015
Definition of the spreading coefficient
S = SFTF - (SFTA + IFT)
S Spreading Coefficient
SFTF Surface Tension of the Fuel
SFTA Surface Tension of the Extinguishing Agent
IFT Interfacial Tension between the Fuel and the
AqueousPhase
If S > 0, an aqueous film is formed.(S > 0 is a necessary, but not a sufficient condition.)
Ralf Hetzer6
05.03.2015
Militarily Important Fuels
Fuel SFTF (24 °C) Sample Origin
Diesel 28,3 mN/m BP Refinery Emsland, Germany
Jet fuel 26,7 mN/m BP Refinery Emsland, Germany
F-34 25,8 mN/m Bundeswehr (NATO Standard Fuel)
Cyclohexan 24,9 mN/m Reference substance
S = SFTF - (SFTA + IFT)
=> (SFTA + IFT) < 25 mN/m
Ralf Hetzer7
05.03.2015
Surfactant Types
Surfactant Type min. SFTA (20 °C)
1. Fluorosurfactants (PFC) 15 mN/m
2. Siloxane surfactants 20 mN/m
4. Alkylsurfactants 28 mN/m
5. no surfactant (pure water) 73 mN/m
S = SFTF - (SFTA + IFT)
(SFTA + IFT) < 25 mN/m
=> SFTA <<25 mN/m
Ralf Hetzer8
05.03.2015
Siloxane Surfactant T-C3-Malt
T-C3-Malt
Ralf Hetzer9
05.03.2015
Synthesis of T-C3-Malt
Problems: time consuming and low yields.
Ralf Hetzer10
05.03.2015
Interfacial Characteristics T-C3-Malt
Chemical CompositionSFTA
[mN/m]
IFT#
[mN/m]
S#
[mN/m]
Film on
Cyclohexane
Film on
F-34
16.8 g/l Glucopon 215 CS UP
2.5 g/l BDG28.5 1.0 - 4.5 No No
2
6.8 g/l Glucopon 215 CS UP
2.5 g/l BDG
0.25 g/l T-C3-Malt
25.8 0.8 - 1.6 No Yes*
3
6.8 g/l Glucopon 215 CS UP
2.5 g/l BDG
0.50 g/l T-C3-Malt
24.1 0.7 0.2 Yes Yes
4
6.8 g/l Glucopon 215 CS UP
2.5 g/l BDG
1.00 g/l T-C3-Malt
23.5 0.5 1.0 Yes Yes
5
6.8 g/l Glucopon 215 CS UP
2.5 g/l BDG
2.00 g/l T-C3-Malt
22.2 0.4 2.4 Yes Yes
#: based on Cyclohexane (SFTF=25.0 mN/m);
*: small area film formation, recontracting after a short term.
Ralf Hetzer11
05.03.2015
Foam Characteristics
Experimental Setup
Foaming Device: Micro Foam Unit, MFU
V-25, (Jürgen Arens,
Cologne, Germany).
Nozzle: Low Expansion
(also Jürgen Arens).
Discharge Rate: 1.06 Kg/min.
Working Pressure: 4,5 bar.
Graduated Cylinder : 2000 ml nominal volume,
2330 ml total volume.
Electronic Balance and Stop Watch.
Ralf Hetzer12
05.03.2015
Foam Characteristics of T-C3-Malt
Chemical Composition Expansion Factor50%-Drainage Time
[min]
1
6.8 g/l Glucopon 215 CS UP
2.5 g/l BDG10.66 ± 0.16 05:39 ± 0:03
2
6.8 g/l Glucopon 215 CS UP
2.5 g/l BDG
0.25 g/l T-C3-Malt
10.76 ± 0.08 5:44 ± 0:02
3
6.8 g/l Glucopon 215 CS UP
2.5 g/l BDG
0.50 g/l T-C3-Malt
10.89 ± 0.15 5:36 ± 0:02
4
6.8 g/l Glucopon 215 CS UP
2.5 g/l BDG
1.0 g/l T-C3-Malt
10.80 ± 0.09 6:00 ± 0:05
5
6.8 g/l Glucopon 215 CS UP
2.5 g/l BDG
2.00 g/l T-C3-Malt
10.88 ± 0.11 6:05 ± 0:03
Ralf Hetzer13
05.03.2015
Commercially Available Foams
Commercial
Firefighting foam
PFC-
containing
Concentration
in Water [%]Expansion
50%-Drainage
Time [min]
1 AFFF 1 Yes 3 10.09 ± 0.16 6:38 ± 0:04
2 AFFF 2 Yes 3 10.29 ± 0.05 6:09 ± 0:06
3PFC-free
Class B Foam 1No 3 9.50 ± 0.06 15:21 ± 0:21
4PFC-free
Class B Foam 2No 3 9.85 ± 0.03 21:16 ± 0:22
5PFC-free
Class B Foam 3No 3 9.28 ± 0.29 2:26 ± 0:06
Chemical Composition Expansion Factor50%-Drainage Time
[min]
16.8 g/l Glucopon 215 CS UP2.5 g/l BDG
10.66 ± 0.16 05:39 ± 0:03
26.8 g/l Glucopon 215 CS UP
2.5 g/l BDG0.25 g/l T-C3-Malt
10.76 ± 0.08 5:44 ± 0:02
36.8 g/l Glucopon 215 CS UP
2.5 g/l BDG0.50 g/l T-C3-Malt
10.89 ± 0.15 5:36 ± 0:02
46.8 g/l Glucopon 215 CS UP
2.5 g/l BDG1.0 g/l T-C3-Malt
10.80 ± 0.09 6:00 ± 0:05
56.8 g/l Glucopon 215 CS UP
2.5 g/l BDG2.00 g/l T-C3-Malt
10.88 ± 0.11 6:05 ± 0:03
Ralf Hetzer14
05.03.2015
Small Scale Fire Tests
Experimental Setup
Pan: EN 3-7,
55B (0.8 – 1.8 kg/min×m²)
21B (>1.8 kg/min×m²).
Water Buffer: 3 cm
Fuel: F-34 (10 l)
Nozzle: Low Expansion
Foam: Premixed Solution
Discharge Rate: 1.06 Kg/min
Foam Solution Reservoir: 25 l (premix)
Working Pressure: 4,5 bar
Burn Back Pot: Height: 10.0 cm
Radius: 5.8 cm
Fuel: Heptane
Ralf Hetzer15
05.03.2015
Small Scale Fire Tests – 99% Extinguishing Time
0
100
200
300
400
500
0.5 1 1.5 2 2.5 3 3.5
99
% E
xtin
gusi
hin
g Ti
me
[s]
Application Rate [kg / (min x m²)]
AFFF 1 AFFF 2
PFC-free Class B Foam 1 PFC-free Class B Foam 2
PFC-free Class B Foam 3 6.8 g/l Glucopon, 2.5 g/l BDG
6.8 g/l Glucopon, 2.5 g/l BDG, 0.25 g/l T-C3-Malt 6.8 g/l Glucopon, 2.5 g/l BDG, 0.50 g/l T-C3-Malt
6.8 g/l Glucopon, 2.5 g/l BDG, 1.00 g/l T-C3-Malt
Ralf Hetzer16
05.03.2015
Small Scale Fire Tests – 100% Extinguishing Time
0
100
200
300
400
500
0.5 1 1.5 2 2.5 3 3.5
10
0%
Ext
ingu
sih
ing
Tim
e [
s]
Application Rate [kg / (min x m²)
AFFF 1 AFFF 2PFC-free Class B Foam 1 PFC-free Class B Foam 2PFC-free Class B Foam 3 6.8 g/l Glucopon, 2.5 g/l BDG, 1.00 g/l T-C3-Malt6.8 g/l Glucopon, 2.5 g/l BDG, 0.50 g/l T-C3-Malt 6.8 g/l Glucopon, 2.5 g/l BDG, 0.25 g/l T-C3-Malt6.8 g/l Glucopon, 2.5 g/l BDG
Ralf Hetzer17
05.03.2015
Burn Back Experiments
0
200
400
600
800
1000
1200
1400
0.5 1 1.5 2 2.5 3 3.5
25
% R
eig
nit
ion
Tim
e [
s]
Application Rate [kg / (min x m²)]
AFFF 1 PFC-free Class B Foam 1
PFC-free Class B Foam 2 AFFF 2
6.8 g/l Glucopon, 2.5 g/l BDG, 1.00 g/l T-C3-Malt 6.8 g/l Glucopon, 2.5 g/l BDG, 0.50 g/l T-C3-Malt
6.8 g/l Glucopon, 2.5 g/l BDG, 0.25 g/l T-C3-Malt 6.8 g/l Glucopon, 2.5 g/l BDG
Ralf Hetzer18
05.03.2015
Revised ICAO Test Protocol
Source: ICAO AIRPORT SERVICE MANUAL, Doc 9137-AN/901 Part 1 (07.2013).
Ralf Hetzer19
05.03.2015
ICAO Fire Test
99%-Extinguishing Time (only flickers left) Burn Back Experiment
Experimental Set-Up Start Foam Application
Ralf Hetzer20
05.03.2015
Results of ICAO B Fire Tests
Type of Foam
Solution
Chemical Composition /
Commercial FoamExtinguishing Time [s]
25%-Burn
Back Time [s]
Requirements ≤ 60 (99%) ≤ 120 (100%) ≥ 300
PFC-free
siloxane based foam
solution
6.8 g/l Glucopon 215 CS UP
2.5 g/l BDG
2.0 g/l new siloxane surfactant
42 70 641
45 66 660
6.8 g/l Glucopon 215 CS UP
2.5 g/l BDG
2.0 g/l new siloxane surfactant
0.15 g/l Xanthan gum
45 60 n.d.
47 60 n.d.
PFC-containing
AFFF
according to
TL 4210-0112
AFFF 1 59 88 573
53 98 604
AFFF 2 41 87 756
43 82 779
AFFF 342 78 863
50 75 752
Ralf Hetzer21
05.03.2015
Conclusions
Conclusions
• The new siloxane surfactants form aqueous films on cyclohexane and
militarily important fuels.
• These siloxane surfactants are compatible with foam forming glyscoside
surfactants.
• In fire test the perfomance of the siloxanes based foams is only surpassed by
the fluorine-containing AFFF.
• Fluorine-free Class B foams are clearly performing less good than the
siloxane-containing blends.
Future work
• Further fire tests according to international standards, e.g. ICAO B and C.
• Formulation of a long-term storable concentrate based on the
experimental siloxane
Ralf Hetzer22
12 February 2014
AFFF
Thank you for
your kind
attention.
Questions?
Ralf Hetzer23
05.03.2015