ArticlePDF Available

Fire Extinguishing Efficiency of Compressed Air Foam, Water and Gel Forming Agents in a Standard Class A Test Fire

Authors:

Abstract and Figures

Aim: The purpose of this article is to evaluate the extinguishing efficiency of water, compressed air foam and gel forming agents in solid materials fires. Project and methods: Comparison of the efficiency of extinguishing water, gel forming agents and compressed air foam was performed by conducting an experimental study to determine the appropriate indicator. An experimental device of the compressed air foam system was used for the study. The model fire of class 1A was selected as the fire. Comparison of extinguishing compounds was evaluated by extinguishing efficiency indicator Ie.e. There were two experiments, with three series in each. Results: Extinguishing efficiency indicator Ie.e took into account the time, and the mass of extinguishing agents needed to extinguish the model fire. Therefore, it was established that the mass of the compressed air foam used for extinguishing is 6.1 kg, which is 47% less than the mass of water used for extinguishing the test fire. With respect to the gel forming agent, the mass required for quenching was equal to 6.53 kg. This is 45% less than the weight of water and 2% less than the mass of compressed air foam. With respect to the quenching time, the greatest amount of time was observed for water. Time required for extinguishing (τ) amounted to 99 seconds. This value is 39% greater than the time it took to quench the flames using gel forming compounds, which was equal to 60 seconds. The minimum time required to extinguish the model fire (τ) was observed for compressed air foam, and was found to be 55 seconds. This is 45% less than that for water and 10% less than the time recorded for gel forming agent. Therefore, it was found that the fire extinguishing efficiency of compressed air foam is more than 80% higher than the water’s, and 15% higher in relation to gel forming agents. Conclusions: The authors analysed fire extinguishing agents that can be used to extinguish solid combustible substances. Experimental studies with standard model A fires let them to determine a quenching efficiency indicator Ie.e. Compressed air foam was found to have the highest fire extinguishing efficiency compared to water and gel forming agents. The advantages of compressed foam are due to the technology of its formation. Such foam has a high cooling and insulating ability, which is well reflected in its fire extinguishing efficiency compared to other extinguishing agents.
Content may be subject to copyright.
SFT VOL. 55 ISSUE 1, 2020, PP. 154–160
SAFETY & FIRE TECHNOLOGY 154
Stanislav Shakhova)*, Stanislav Vinogradova)
a) Nationa l University of Civil Defence of Ukraine
* Corresponding author / Autor korespondencyjny: lophennss@gmail.com
Fire Extinguishing Efficiency of Compressed Air Foam, Water and Gel Forming
Agents in a Standard Class A Test Fire
Porównanie skuteczności gaśniczej piany sprężonej, wody i związków
żelotwórczych podczas gaszenia pożaru modelowego klasy A
ABSTRACT
Aim: The purpose of this article is to evaluate the ex tinguishing efciency of water, compressed air foam and gel forming agents in solid materials res.
Project and methods: Comparison of the ef ciency of extinguishing water, gel forming agents and compressed air foam was performed by conducting
an experimental study to determine the appropriate indicator. An experimental device of the compressed air foam system was used for the study. The
model re of class 1A was selected as the re. Comparison of extinguishing compounds was evaluated by extinguishing efciency indicator Ie.e. There
were two experiments, with three series in each.
Results: Extinguishing efciency indicator Ie.e took into account the time, and the mass of extinguishing agents needed to extinguish the model re.
Therefore, it was established that the mass of the compressed air foam used for extinguishing is 6.1 kg, which is 47% less than the mass of water used
for extinguishing the test re. With respect to the gel forming agent, the mass required for quenching was equal to 6.53 kg. This is 45% less than the
weight of water and 2% less than the mass of compressed air foam. With respect to the quenching time, the greatest amount of time was obser ved for
water. Time required for extinguishing (τ) amounted to 99 seconds. This value is 39% greater than the time it took to quench the flames using gel forming
compounds, which was equal to 60 seconds. The minimum time required to extinguish the model re (τ) was observed for compressed air foam, and
was found to be 55 seconds. This is 45% less than that for water and 10% less than the time recorded for gel forming agent. Therefore, it was found
that the re extinguishing efciency of compressed air foam is more than 80% higher than the water’s, and 15% higher in relation to gel forming agents.
Conclusions: The authors analysed re extinguishing agents that can be used to ex tinguish solid combustible substances. Experimental studies with
standard model Ares let them to determine aquenching ef ciency indicator Ie.e. Compressed air foam was found to have the highest re extinguishing
efciency compared to water and gel forming agents. The advantages of compressed foam are due to the technology of its formation. Such foam has
ahigh cooling and insulating ability, which is well reflected in its re extinguishing efciency compared to other extinguishing agents.
Keywords: extinguishing efciency, class Are, water, CAF, gel
Type of article: original scientic article
Received: 26.04.2020; Reviewed: 20.05.2020; Accepted: 27.05.2020;
Authors` ORCID IDs: Stanislav Shakhov – 0000-000 3-3914-2914; Stanislav Vinogradov – 0000 -0003-256 9-5 489;
The authors contributed the equally to this ar ticle;
Please cite as: SFT Vol. 55 Issue 1, 2020, pp. 154–160, https://doi.org/10.12845/sft.55.1.2020.10;
This is an open access ar ticle under the CC BY-SA 4.0 license (https://creativecommons.org/licenses/by-sa/4.0/).
ABSTRAKT
Cel: Celem art ykułu jest ocena skuteczności gaśniczej wody, piany sprężonej izwiązków żelotwórczych podczas gaszenia stał ych substancji palnych.
Projek t i metody: D okonano porównania skuteczności gaśniczej wody, związków żelotwórczych i piany sprężonej poprzez przeprowadzenie bad
eksperymentalnych w celu ustalenia odpowiedniego wskaźnika. Do badań użyto eksperymentalnego ur ządzenia z pianą spreżoną. Wybrano pożar
testowy klasy 1A. Porównanie środków gaśniczych oceniono na podstawie wskaźnika skuteczności gaszenia Ie.e. Przeprowadzono dwa eksperymenty,
po trzy serie wkażdym znich.
Wyniki: Wskaźnik skuteczności gaszenia uwzględniał czas imasę środka gaśniczego potrzebnego do ugaszenia pożaru modelowego. Ustalono, że masa
piany sprężonej uży tej do gaszenia wynosi 6,1 kg, co oznacza o47% mniej niż masa wody uż ytej do gaszenia pożaru próbnego. Wprz ypadku związków
żelotwórczych wymagana masa wynosi 6,53 kg. Jest to o45% mniej niż masa wody i2% mniej niż masa piany spreżonej. Zbadań wynika, że najwięcej
czasu zajmuje gaszenie wodą. Obliczona dla niej wartość: τ = 99 sekund jest o39% większa niż czas potrzebny do schłodzenia związków żelotwórczych,
który wyniósł dla nich 60 sekund. Najkrótszy czas wymagany do gaszenia pożaru modelowego jest obserwowany dla piany sprężonej iwynosi 55 sekund.
SFT VOL. 55 ISSUE 1, 2020, PP. 154–160
SAFETY & FIRE TECHNOLOGY 155
Jest to o45% mniej niż wprzypadku wody io10% mniej wodniesieniu do związków żelotwórczych. Stwierdzono zatem, że skuteczność gaśnicza piany
spreżonej jest większa o80% wstosunku do wody io15% większa wodniesieniu do związków żelotwórczych.
Wnioski: Przeanalizowano środki gaśnicze, k tóre można zastosować do gaszenia stałych substancji palnych. Badania eksperymentalne pozwoliły
ustalić wskaźnik skuteczności gaszenia pożarow klasy A. Wynika znich, że piana sprężona ma najwyższą zdolnoś ć gaśniczą wporównaniu do wody
izwiązków żelotwórczych, co wynika ztechnologii jej powstawania. Taka piana ma w ysoką zdolność chłodzenia iizolowania, co dobrze wp ływa na jej
skuteczność gaszenia.
Słowa kluczowe: skuteczność gaśnicza, pożar klasy A, ogień, woda, CAF, żel
Typ artykułu: oryginalny artykuł naukowy
Przyjęty: 26.04.2020; Zrecenzowany: 20.05.2020; Zaakceptowany: 27.05.2020;
Identy katory ORCID autorów: Stanislav Shakhov – 0000- 0003-3914-2914; Stanislav Vinogradov – 0000- 0003-2569 -54 89;
Autorzy wnieśli równy wkład mer ytoryczny w powstanie artykułu;
Proszę cy tować: SFT Vol. 55 Issue 1, 2020, pp. 154–160, https://doi.org/10.12845/sft.55.1.2020.10;
This is an open access ar ticle under the CC BY-SA 4.0 license (https://creativecommons.org/licenses/by-sa/4.0/).
Introduction
Today, solids and materials are the most widespread in pro-
duction, economy and everyday life [1]. In the conditions of extin-
guishing fires involving solid combustibles, water is the main
extinguishing agent [2–4]. But despite its advantages, wide-
spread application, ease of use and economic feasibility, only
5–10% of water is actually used to extinguish fires. In fact, the
remaining 90–95% is excessively spilled, resulting in a significant
loss of this precious resource [5]. The urgency of the problem of
poor water use, along with the technological development and
emergence of modern extinguishing agents, make it necessary
to search for alternative and effective ways of extinguishing fires.
One of the modern methods that can be applied to extinguish
solids more efficiently is to use gel forming agents that have
several advantages over water [6–7]. According to an experimen-
tal study by O. V. Savchenko, O. O. Kiryeyev, and others [8] the effi-
ciency of gel forming agents in the quenching of solids is 40%
greater than that of water.
Also compressed air foam systems have become wide-
spread. Compressed Air Foam (CAF) is a homogeneous,
low-multipurpose foam obtained by mixing water, foam and air,
or nitrogen under pressure [9–10]. Several authors have noted
that CAF has the following advantages over traditional fire extin-
guishing agents and methods: CAF is highly structured, compact
and consists of a large number of homogeneous single bubbles;
the mass to surface ratio is favourable for intense heat transfer,
resulting in a significant cooling effect; since CAF is formed by
means of pressurized air, the use of energy from this pressure is
sufficient to deliver it directly to the fire [11–18]. At the same time
there is no evaporation of small droplets at the stage of delivery
of the jet into the focus of the fire, which increases the coeffi-
cient of use of the extinguishing agent; CAF can be used to extin-
guish live electrical equipment; CAF may have an increased liquid
phase composition that enhances the cooling effect, as well as
high stickiness ability that allows it to be used for the fire protec-
tion of vertical surfaces; the absence of the liquid phase reduces
direct damage during the extinguishing of fires in multi-storey
buildings and in attics due to the lack of flooding of lower floors.
In their previous articles [19–20] the authors have conducted
experimental studies to determine the effect of foam expansion
ratio on its extinguishing properties, namely the effect of com-
pressed foam expansion ratio on its dispersion and stability.
They examined the change in the average diameter of foam bub-
bles in relation to the expansion ratio of foam. The stability of
the compression foam was measured according to the methods
described in standards [21–22]. The previously unknown depend-
encies for compressed foam, which has absolutely different prop-
erties than the foam formed by the air-mechanical method have
been as follows:
the higher expansion ratio of the foam, the greater its sta-
bility; the lowest foam stability is observed at the foam
expansion ratio of 5 and equals to 4.5 minutes. Further
increased foam expansion ratio values up to 12.5 are
accompanied by an increase in the stability of 66% and
equals to 13.16 minutes;
with increasing the expansion ratio from 5 to 20, there is
a maximum foam resistance of 21.83 min, a percentage
increase in the stability of almost 80%;
with increasing expansion ratio there is a decrease in the
size of the foam bubble, which leads to an increase in the
time of its existence, resulting in the formation of highly
dispersed foam; increasing the expansion ratio of foam
from 5 to 20 leads to a decrease in the diameter of the
bubble by 15;
with increasing foam expansion ratio, the uniformity
increases, i.e. when determining the size range of
foam bubbles with an expansion ratio of 12.5, the dia-
meters of the bubbles were in the range of 0.09 mm to
0.13 mm, which is 66% less than the diameter range for
foam expansion ratio of 5;
the greatest uniformity of bubbles was observed for foam
with the expansion ratio of 20, where the range of diame-
ters varied from 0.09 mm to 0.11 mm;
compared to the size difference of foam bubbles with
an expansion ratio 6, the decrease was by 80%.
SFT VOL. 55 ISSUE 1, 2020, PP. 154–160
SAFETY & FIRE TECHNOLOGY 156
In respect to the extinguishing of solid combustibles,
an experimental study was carried out by the authors in cooper-
ation with A. I. Kodrik, O. M. Titenko [23–24] to determine the fire
extinguishing efficiency of CAF, during the extinguishing of labora-
tory class A fires. The study used 3 foaming agent concentrations:
4%, 5% and 6%. It was determined that the expansion ratio of foam
significantly affects the fire extinguishing efficiency. Thus, increas-
ing the foam expansion ratio from 15 to 20 leads to the improve-
ment of the quenching efficiency by 21%, whereas from 20 to 25
– by only 2%. However, the highest extinguishing efficiency was
proved for a solution with a concentration of 6% foaming agent.
On the basis of the results of the experiment, the fire extinguish-
ing efficiency of the compressed foam was confirmed, as was the
expediency of its use for the extinguishing of solid combustible
substances in the form of laboratory class A fires.
X. Wang and colleagues conducted experimental studies on the
effectiveness of extinguishing fires of solid fuels with prepared mul-
ticomponent foam premixes [25]. Fire extinguishing was carried out
under various conditions, such as different foam concentrations
or structure of the front of the mixing chamber and working pres-
sure. It was found that the concentration of the foam had a suffi-
cient influence on the effectiveness of firefighting, and there was
an optimised concentration value. In case of solid combustible sub-
stances fires the working concentration of the foaming agent was
about 4.0%. Increasing the working pressure in the system also had
a positive effect on the extinguishing of the fire. Also the authors
of a paper entitled Experimental study on the performance of class
Afoam in extinguishing class Afires conducted an experimental study
to quantify the effectiveness of compressed foam in extinguishing
class A fires of solid combustible substances [26]. The effect of the
mixing ratio, expansion ratio, and some other parameters, on the
quenching efficiency, which was compared with the characteristics
of water, was examined. The results showed that the rate of extin-
guishing using commercial foam was 20% faster than when extin-
guishing with water. The best fire extinguishing effect was achieved
with a mixing ratio in the range from 0.2% to 0.5% and a ratio in the
range from 5 to 15. The study [27] was aimed at examining and com-
paring fire extinguishing efficiency of water, water with a wetting
agent and compressed foam, when extinguishing standard fires of
combustible substances. Its results show that compressed foam
suppresses fire most effectively under test conditions.
Among extinguishing agents that can be used to supress class
A fires, water, gel forming systems compounds and compressed
foam have become widespread. However, there is not any known
research comparing the extinguishing effectiveness of these agents.
The purpose of this article is to conduct an experimental evaluation
of the extinguishing efficiency of water, CAF and gel forming agents
in terms of the numerical indicator of their extinguishing ability for
solid fires, and to compare them with one another.
The methodology of the experiment
Comparison of the extinguishing efficiency of water, gel form-
ing agents and CAF was performed by conducting an experimen-
tal study to determine the appropriate indicator.
Due to the fact that gel forming agents, water and compres-
sion foam are different substances, it is difficult to apply the
same intensity to them. Therefore, in order to be able to com-
pare the results obtained for these substances, the authors used
the extinguishing efficiency index Ie.e, which takes into account
the amount of substance applied for a certain time per unit area
of the model fire. Thus, the numerical value of the extinguishing
efficiency of different substances can be compared, even if they
are applied to different intensities.
Comparison of extinguishing compositions was estimated
by extinguishing efficiency indicator Ie.e according to the already
mentioned publications [2], [4]. The quenching efficiency was cal-
culated using the formula:
(1)
where:
Sf – fire area
Ge.a = total amount of extinguishing agent, used during τ.
The amount of substance used Ge.a is equal to the mass of
the substance used for extinguishing ma , hence in the subsequent
calculations the value ma was used.
An experimental device of the compressed foam feed sys-
tem was used for the study [28]. Figure 1 shows a diagram (a)
and a photo (b) of the experimental device.
(a) (b)
Figure 1. Sc heme „a” and p hoto „b” of the exp erimental d evice of
compr essed air foam sy stem: 1 – contain er for solutio n of foaming agen t;
2 – compr essed air ball oon or compre ssor; 3 – gas redu cer for regula tion of
pressu re and consum ption of air; 4 – the o riginal foam m ixer; 5 – regula ting
valves for the ow rate of the foam premix and air; 6 – pipelines for supplying
a soluti on of foaming ag ent and compr essed air
Source: S. M. Shahov, Rozrob ka eksperim entalnoyi usta novki dlya
provede nnya doslidzhe n vlastivostej ko mpresijnoyi p ini, Proble mi ta perspek tivi
zabezpechennya civilnogo zahistu, Sbirnik te z dopovidej Miz hnar. nauk-pr akt.
konf., Har kiv, 2019, 185 [26].
An experimental study to determine the fire extinguishing effi-
ciency of gel forming agents during the quenching of standard
class 1A fires has been already conducted by O. O. Kireev and
Y. V. Savchenko [8].
Therefore, for further comparison of extinguishing compo-
sitions the authors selected a model fire class 1A, which was
a wooden pile of ordinary pine with 72 bars (40 × 40 mm) section
and a length of 500 mm, enclosed in six rows. Moisture of pine
SFT VOL. 55 ISSUE 1, 2020, PP. 154–160
SAFETY & FIRE TECHNOLOGY 157
timber was 10%. The total open area of the model fire was 5.99 m2.
The area, taking into account the overlap of the bars in the assem-
bled state, was 4.7 m2.
In the above-mentioned paper by O. V. Savchenko et al., the
most effective gel forming agent for extinguishing solids was
established [8]. The time spent on extinguishing the standard
1A test fire was 60 s, and the mass of gel forming agents consti-
tuted 6.53 kg. The results obtained has been sufficient to carry
out the calculation and numerical expression of the gel forming
agents extinguishing efficiency, in a form of a quenching efficiency
Ie.e indicator. Therefore, the experiment of extinguishing the stand-
ard class 1A model fire with gel forming agent was not conducted.
During the comparison of water and compressed foam, the
study reproduced conditions that repeated the circumstances of
the previous experiment [8] to determine the fire extinguishing
efficiency of gel forming compositions.
The conditions of the experiment were in accordance with the
standard [29, p. 33]. The tests were conducted in the open air at
a wind speed of 1÷2 m/s, the air temperature was 100°C. A port-
able platform was installed at the designated location. Metal
posts made of steel corners were used as supports. Next, a pile
of firewood was stacked at the racks. The distance from the plat-
form to the base of the stack was (400 ± 10) mm. Subsequently,
a 400 mm × 400 mm × 100 mm metal deck was introduced under
the stack. The deck was installed horizontally, the bottom was
covered with a layer of water 30 mm thick, 1.1 litres of A-92 gas-
oline was filled to it.
Figure 2 shows a photo of a model fire at the beginning of
the combustion and after a certain time of free combustion. The
fuel in the deck was set on fire, after burning (120–160 s), the
deck was removed from under the stack. The ignition time of the
model fire was approximately ~7 minutes.
(a) (b)
Figure 2 . Photo of the model standard re: a) the beginning of burning,
b) burni ng after 7 minute s
Source: Authors’ own archives. Figure 3 . Fire exting uishing proc ess with: a) water, b) with t he use of the
exper imental syste m for supplyi ng compresse d air foam
Source: Authors’ own archives.
Figure 3 presents the process of extinguishing the model fire
with: a) water, b) compressed air foam. The extinguishing of the
fire complied with the requirements of DSTU (State standard of
Ukraine) 3675-98. After burning 45% of the mass of the stack,
(400–440 s with free combustion), extinguishing began.
(a)
(b)
According to DSTU 3675-98, after extinguishing, a model fire
was observed for 10 minutes for reignition. If it did not occur, the
model fire was considered extinguished.
SFT VOL. 55 ISSUE 1, 2020, PP. 154–160
SAFETY & FIRE TECHNOLOGY 158
Figure 4 shows photos of model fires after extinguishing with
a) water, b) compressed air foam.
(a)
(b)
Figure 4 . Photo of the model re after extinguishing with a) water,
b) compre ssed air foam
Source: Authors’ own archives.
Figure 5 . The mass of water, ge l forming age nts, and comp ressed air foam
required for extinguishing class A res
Source: Own elaboration.
The mass of the extinguishing agent ma was determined
by weighing the container with the extinguishing agent before
extinguishing and after complete elimination of the flames at
the model site. The time τ was fixed from the beginning of the
direction of the extinguishing jet towards the centre of the fire,
until the moment of complete extinguishing. There were 2 exper-
iments, 3 series in each. The average mass of the extinguishing
composition and the time to extinguishing were then calculated.
Results of experimental studies
Summarised results of the experiment are given in Table 1.
Extinguishing agent
Mass of agent ma, [kg] Extinguishing time τ, [s] S, [m2]
1 2 3 1 2 3
4.7
m1m2m3τ 1 τ 2 τ 3
Water 10.3 13.2 11 11.55 105 97 95 99
CAF 5.8 6.5 6 6.1 63 52 50 55
Gel forming agents 6.53 60
Based on the experimental data obtained and the results of
the study by O. V. Savchenko et al., Ie.e quenching performance
for water, compressed air foam, and gel forming compounds was
calculated [8]. The results of the calculations are given in Table 2.
Table 1. Results of the extin guishing of class A re with water and compressed air foam
Source: Own elaboration.
Table 2. Cal culated Ie.e data for diffe rent re extinguishing compositions
Source: Own elaboration.
Extinguishing agent Ie.e х 10–3,
Water 4.12
Gel forming agents 11.9
CAF 14
Discussion of results
Figure 5 shows a graph of the mass of extinguishing agents
required to extinguish the class 1 A model fire.
Water CAF GEL
Extinguishing agent
Mass of agent ma, kg
12
10
8
6
4
2
0
The mass of CAF used for extinguishing is ma= 6.1 kg, which is
47% less than the mass of water used for extinguishing the model
fire. With respect to the gel forming agents, the mass required for
quenching was ma= 6.53 kg. This is 45% less than the weight of
water and 2% more than the mass of compressed air foam.
SFT VOL. 55 ISSUE 1, 2020, PP. 154–160
SAFETY & FIRE TECHNOLOGY 159
Figure 6 . Amount of time required to extinguish a Class A re with water, gel
formi ng agents and co mpressed air f oam
Source: Own elaboration.
Figure 7. Grap hic represe ntation of the Ie.e q uenching pe rformanc e for water,
gel for ming agents , and compress ed air foam
Source: Own elaboration.
Figure 6 is a graph showing the amount of time it takes to
extinguish a class 1A model fire.
Water CAF GEL
Extinguishing agent
Estinguishing time τ, s
100
90
80
70
60
50
40
30
20
10
0
Based on the graph data (Fig. 6), the largest amount of time
to extinguish the model fire is required for water. It constituted
99 seconds. This value is 39% greater than the time it took to
quench the flames using gel forming agents (τ = 60 seconds). The
minimum time required to extinguish model fire was observed for
compressed foam and was equal to 55 seconds. This is 45%
less than for water, and 10% less than the time to for gel form-
ing compounds.
Figure 7 shows a graphical comparison of I e.e quenching per-
formance for water, compressed air foam and gel extinguishing
agents.
Water CAF GEL
Extinguishing agent
Ie.e
16
14
12
10
8
6
4
2
0
By analysing the graph (Fig. 7) it can be stated that the high-
est extinguishing ability in terms of quenching efficiency Ie.e was
observed for compressed air foam, and its numerical value is
Ie.e = 14 х 10–3
s x kg
m
2
. Based on the graph, the fire extinguishing
efficiency of compressed air foam is greater than that of water by
80% and greater than that of gel forming agents by 15%.
The advantages of compressed air foam over water and gel
forming agents are due to the technology of its formation. Dur-
ing the process of its generation, a large number of homogene-
ous bubbles of small size are formed. This leads to the forma-
tion of a homogeneous fine foam, which makes it more stable.
Such foam has a high cooling and insulating ability, which is well
reflected in its fire extinguishing efficiency compared to other
extinguishing agents.
Conclusions
The authors analysed the use of extinguishing agents for
extinguishing fires of solid combustible substances. The main
fire extinguishing substances that can be used for extinguish-
ing class A fires were identified. An experimental study to extin-
guish standard model fires 1A with water and compressed air
foam was conducted. The study compared the extinguishing effi-
ciency of water, compressed air foam and gel forming agents,
which was numerically evaluated by the Ie.e. During extinguish-
ing of the model fire with water, the value of the quenching effi-
ciency index was Ie.e = 4,12 x 10–3
s x kg
m
2
, but after extinguishing
the model hearth, after 5 minutes there was a reignition. The indi-
cator for the gel forming agents was Ie.e = 11,9 x 10–3
s x kg
m
2
, which
is 65% more than the extinguishing efficiency of water. The high-
est extinguishing efficiency in terms of quenching efficiency was
observed for compressed foam and was Ie.e = 14 x 10–3
s x kg
m
2
,
which is 80% more than water and 15% more than gel forming
agents.
Therefore, this experimental study made it possible to estab-
lish the most effective extinguishing agent for the extinguish-
ing of solid combustible substances. In terms of quenching effi-
ciency, compressed air foam has the highest fire extinguishing
capacity compared to water and gel forming agents.
Literature
[1] Abduragimov I. M., Androsov A. C., Isaeva L. K., Krylov E. B.,
Processy goreniya, VIPTSh MVD SSSR, Moskva 1984, 268.
[2] Bobkov S. A. Baburin A. V., Komrakov P. V., Fiziko–himiche-
skie osnovy razvitiya i tusheniya pozharov, AGPS MChS RF,
Moskva 2014, 210.
[3] Abduragimov I. M., Govorov V. Yu., Mkarov V. E., Fiziko–
himicheskie osnovy razvitiya i tusheniya pozharov, VIPTSh,
Moskva 1980, 255.
[4] Rashoyan I. I., Fiziko–himicheskie osnovy razvitiya i tushe-
niya pozhara, Tolyatti, 2013, 107.
[5] Teterin I. M., Temperaturno–aktivnaya voda – novaya para-
digma razvitiya tehniki pozharotusheniya, „Sredstva tushe-
niya: zhurnal–katalog” 2005, 44.
[6] Savchenko O. V., Kireev O. O., Optimizaciya kil kisnogo sklad u
geleut voryuyuchoyi sistemi dlya g asinnya pozhezh ob’yek tiv
SFT VOL. 55 ISSUE 1, 2020, PP. 154–160
SAFETY & FIRE TECHNOLOGY 160
zhitlovogo sektoru, „Problemy pozharnoj bezopasnosti”
2009, 25, 162–166.
[7] Savchenko O. V., Eksperimentalne viznachennya vognega-
snoyi zdatnosti optimizovanogo ki lkisnogo skladu geleutvo-
ryuval noyi sistemi CaCl2 – Na2O ·2,95 S iO2 – N2O, „Pozhezhna
bezpeka” 2010, 16, 109–114.
[8] Savchenko O. V., Kiryeyev O. O., Ostroverh O. O, Vizna-
chennya pokaznika vognegasnoyi zdatnosti optimizova-
nogo kilkisnogo skladu geleutvoryuyuchoyi sistemi CaCl2
– Na2O·2,95SiO2 – H2O na standartizovanomu modelnomu
vognishi pozhezh, „Problemy pozharnoj bezopasnosti”
2011, 29, 149–155.
[9] http://compressedairfoamsystem.com [accessed: 30.12.2018].
[10] Larin O. M., Vinogradov S. A., Barkalov V. G, Pozhezhni
mashini, MPBP «Gordon», Kharkiv 2016, 279.
[11] Colletti D. J., Compressed–air foam mechanics, “Fire Engi-
neering” 1994, 147, 61–65.
[12] http://www.cafsinfo.com/index.html [accessed: 30.12.2018].
[13] Taylor R. G., Technical Compressed Air Foam Systems
inLimited Staffing Conditions, Report 98. Morristown Fire
Bureau –Morristown, New Jersey, 1998, 75–112.
[14] Zalesov S. V., Godovalov G. A., Krektunov A. A., Opletaev A. S .,
Novyjsposob sozdaniya zagraditelnyh i opornyh protivopo-
zharnyh polos, „Vestnik Bashkirskogo gosudarstvennogo
agrarnogo universiteta” 2014, 3, 90–94.
[15] Zalesov S. V., Godovalov G. A., Krektunov A. A., Sistema
pozharotusheniya NATISK dlya ostanovki i lokal izacii lesnyh
pozharov, „Sovremennyeproblemy nauki i obrazovaniya”
2014, 3, 37–42.
[16] Zalesov S. V., Godovalov G. A., Krektunov A. A., Ispolzova-
nie sistemy pozharotusheniya NATISK pri likvidacii torfyanyh
pozharov, „Lesa Rossii i hozyajstvo v nih” 2016, 1 (56), 4–10.
[17] Huiqing L., Experimental study of foam generated by com-
pressed air foam system, Beijing Forestry University, 2000,
105–111.
[18] Michael A. L., Michael S., Patent No.: US 6,357,532 B1,
Сompressed air foam systems, 2002.
[19] Shahov S. M., Vinogradov S. A., Kodrik A. I., Titenko O. M.,
Vpliv kratnosti kompresijnoyi pini na dispersnist i stijkist,
”Problemi pozhezhnoyi bezpeki” 2019, 45, 27–33.
[20] Shahov S. M., Vinogradov S. A., Kodrik A. I., Titenko O. M.,
Stilik I. G., Viznachennya zalezhnosti harakteristik kom-
presijnoyi pini, „Naukovij visnik NLTU Ukrayini, 2019, 5,
103–106.
[21] DSTU 3789:2015. Pozhezhna bezpeka. Pi`noutvoryuva-
chi` zagal`nogo priznachennya dlya gasi`nnya pozhezh,
DP UkrNDNCz, Kiyiv 2016, 67.
[22] 146. GOST R 50588–2012. Naczional`ny`j standart Rossij-
skoj Federaczii. Penoobrazovateli dlya tusheniya pozharov,
Standartinform, Moskva 2012, 29.
[23] Shahov S. M., Vinogradov S. A., Kodrik A. I., Titenko O. M.,
Viznachennya vognegasnoyi efektivnosti kompresijnoyi pini
pid chas gasinnya neyu tverdih goryuchih rechovin, „Pro-
blemi pozhezhnoyi bezpeki” 2019, 46, 199–205.
[24] Shahov S. M., Vinogradov S. A., Kodrik A. I., Titenko O. M.,
Viznachennya pokaznika vognegasnoyi zdatnosti kom-
presijnoyi pini, „Problemi pozhezhnoyi bezpeki”, 2019, 41,
199–205.
[25] Wang X., Liao Y. & Lin L., Experimental study on fire extin-
guishing with a newly prepared multi-component compres-
sed air foam, “Chin. Sci. Bull.” 2009, 54, 492–496.
[26] Lu Q., Bao Zh., Chen T., Zhang X., Fu X., Experimental study
on the performance of class A foam in extinguishing class
A fires, “Fire Science and Technology” 2013, 2, 337–389.
[27] Rappsilbera T., Belowb P., Krügera S., Wood crib fire tests to
evaluate the influence of extinguishing media and jet type
on extinguishing performance at close rang, “Fire Saftey
Journal” 2019, 106, 136–145, https://doi.org/10.1016/j.
firesaf.2019.04.014.
[28] Shahov S. M., Rozrobka eksperimentalnoyi ustanovki dlya
proveden nya doslidzhen vlastivo stej kompresijnoyi pini, Pro -
blemi ta pe rspektivi zabezpe chennya civilnogo zahistu, Sbir-
nik tez dopovidej Mizhnar. nauk–prakt. konf., Harkiv 2019,
185.
[29] DSTU 3675–98. Pozhezhna tehnika. Vognegasniki pereno-
sni. Zagalni tehnichni vimogi ta metodi viprobuvan, 1999.
STANISLAV SHAKHOV
– a postgr aduate stude nt at the Depar tment
of Engin eering and Rescue Machiner y of the National University of
Civil D efence of Ukr aine. His rese arch interes ts include: c ompressed
ai r fo am, re exti nguis hi ng, res cue wor ks. The auth or (co -au tho r) of
more than 20 scientic publications.
STANISL AV VINOGR ADOV, PH.D – an Associated Professor at the
Depar tment of Engineering and Rescue Mac hinery of the National
University of Civil Defence of Ukraine. Sphere of scienti c interests:
re extinguishing, rescue works, extinguishing gas blowouts, high-
-speed water je ts, compressed air foam. The author (co -author) of
more than 50 scientic publications.
... The most common are water [1-is 5]. a rule, water As used for extinguishing solid combustible substances, and water foam -for extinguishing flammable liquids [6,7]. However, in some cases, the possibility of using water-foam fire-ext form of compress in the inguishing substances ed air foam for extinguishing solid combustible substances has been proven [8] or to help protect forest resources a cooling two of from wildland fires [9, 10], or in the form -glass layer foamed -gel material [11], etc. ...
... The different types of foaming agents in compress of use ed air foam when extinguishing flammable liquids is studied in [16,[19][20][21]. The authors [8] noted the advantages of the AFFF-type film-forming foaming agent [ S. The synthetic the over authors 19 using ] claim that when fluorocarbon surfactants, the foam has an increased film thickness and a lower diffusion coefficient than for protein foaming agents. In [20], the fire-extinguishing efficiency of compressed air foam with fluorine compound (2 a chemical content with the foaming agent of synthetic -bromo-3,3,3trifluoropropene) and without it was compared. ...
Article
Full-text available
The prototype of the compressed air foam system was improved based on the evaluation of the numerical parameters obtained with the help of the developed mathematical model of the foam generation process and the pneumatic-hydraulic scheme. The prototype provides the possibility of foam generation both in autonomous mode, due to the installation of cylinders with compressed gas, and in stationary mode, due to the supply of compressed air from an external source. This allows the use of an improved model of the compressed air foam system both in stationary mode (dry pipes, gas stations, etc.) and for use on heavy and light fire trucks, which is important for large cities. Testing of the improved prototype of the system for extinguishing model fires was carried out. The system provides extinguishing of model fires of class 183 B and 144 B when using both a general-purpose foaming agent and a special film-forming foaming agent. When using a film-forming foaming agent, the extinguishing time was reduced by 1.75 times, the consumption of fire extinguishing solution by 1.47 times. But at the same time, it should be taken into account that the cost of the film-forming foaming agent Sofir (sofirafff 6 %) is more than 3.2 times the cost of the general-purpose foaming agent Sofir. The effectiveness of the improved model in extinguishing class A fires was also confirmed. The autonomous compressed air foam system ensures extinguishing of a class 4 A model fire in 90 seconds. Dry foam with a factor of 14 is noted to be more effective in extinguishing solid combustible substances.
... The accident cases of recent years have shown that normal conventional fire extinguishment technology has difficulty meeting the fire extinguishment requirements of UHVDC converter transformers. CAF has the advantages of high fire extinguishing efficiency, uniform and stable foam, and environmentally friendly chemicals [2][3][4][5]. Therefore, it is important to investigate the characteristics of the CAF to suppress transformer fires. ...
Article
Full-text available
To study the fire behavior of UHVDC (ultra-high-voltage direct current) converter transformers and the effectiveness of CAFs (compressed air foams) in suppressing fires, a full-scale model of a 220 kV converter transformer fire was constructed. The model mainly considered the oil pool fires and oil spill fires that form after explosions, causing the casing to completely fall out. The hot oil fire tests were conducted on the physical converter transformer. The fire suppression characteristics of the CAF system for converter transformer fires were studied. The temperature and changes in various locations of the fire model were analyzed under different foam supply strengths. The fire in a converter transformer is characterized by intense heat, high temperatures, and strong radiation. The highest temperature can exceed 1000 °C in cases of complete combustion. The fire in the converter transformer involves a dynamic oil spill and a large pool of oil, making it challenging to extinguish. The fire extinguishing performance and cooling effect of CAFs are outstanding. The recommended foam supply strength for the actual project is more than 8 L/(min·m2).
Article
This paper is intended to be the first study to discuss the fire suppressing performance of the four most common extinguishing media under the same reproducible conditions. The tests were performed in bench-scale and used standardized 5A wood cribs as well as a miniature extinguishing system with a liquid flow rate of 1.4 lmin ⁻¹ . The tests results present a consistent overview of the fire suppression efficacies of water, water with a foaming agent, nozzle-aspirated foam and compressed air foam. Depending on their jet types, the cooling capabilities of the extinguishing media water and water with a foaming agent were compared to the cooling capability of a full jet of wet, general and dry foams. The results show that compressed air foam suppressed fire most effectively under the test conditions. Because of the convoluted crib structure, water and water with foaming agents used from a distance are more effective in the form of a full jet rather than a spraying jet. At close range, spraying jets multiply their effectiveness. A slight difference can be observed in the cooling performance of extinguishing foams that use foaming agents from different manufacturers. The paper establishes a link between the foaming agent's cooling capability and its wetting power by relating the results of wood crib fire tests according to DIN EN 3–7 and findings from laboratory immersion tests compliant with DIN EN 1772.
Article
A multi-component compressed air foam system (MCAFS) was developed with newly prepared multi-component foaming agents. Extinguishing of wood crib and oil pool fires was performed under different conditions, such as foam concentration, mixing chamber forepart structure and working pressure. It was found that the foam concentration had sufficient effects on fire extinguishing efficiency, and an optimized concentration value exists. For instance, for diesel oil pool fires, this value is about 2.2% while it is about 4.0% for wood crib fires. The results also show that the system with a coaxial mixing chamber has greater efficiency than a T-shape. The effects of working pressure on fire extinguishing are evident in experiments, i.e., the higher the working pressure is, the more readily the fire is extinguished.
Sistema pozharotusheniya NATISK dlya ostanovki i lokalizacii lesnyh pozharov
  • Zalesov S.V.
Compressed-air foam mechanics
  • Colletti D.J.
Colletti D. J., Compressed-air foam mechanics, "Fire Engineering" 1994, 147, 61-65.
Novyj sposob sozdaniya zagraditelnyh i opornyh protivopozharnyh polos
  • Zalesov S. V.
Ispolzovanie sistemy pozharotusheniya NATISK pri likvidacii torfyanyh pozharov
  • Zalesov S.V.
Vpliv kratnosti kompresijnoyi pini na dispersnist i stijkist
  • Shahov S. M.
Optimizaciya kilkisnogo skladu geleutvoryuyuchoyi sistemi dlya gasinnya pozhezh ob’yektiv
  • Savchenko O.V.
Eksperimentalne viznachennya vognega-snoyi zdatnosti optimizovanogo kilkisnogo skladu geleutvo-ryuvalnoyi sistemi CaCl2 – Na2O·2,95 SiO2 – N2O
  • Savchenko O.V.
Savchenko O. V., Eksperimentalne viznachennya vognegasnoyi zdatnosti optimizovanogo kilkisnogo skladu geleutvoryuvalnoyi sistemi CaCl 2 -Na 2 O·2,95 SiO 2 -N 2 O, "Pozhezhna bezpeka" 2010, 16, 109-114.