JPS6147103B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a fire extinguishing composition and a fire extinguishing method using the same. In particular, the present invention relates to fire extinguishing solutions having improved fire extinguishing properties and maximizing the use of conventional fire extinguishing equipment. Conventional fire extinguishing compositions, which may contain various surfactants, do not achieve sufficient extinguishment within acceptable times or have sufficient cooling action to limit deadly smoke. For example, U.S. Pat. No. 3,912,647 discloses a fire extinguishing composition in which a highly concentrated surfactant is blended into a solvent and mixed with water to form a viscous substance. Solvents such as naphtha must be used to provide fluidity, and high concentrations of surfactant, above about 3%, do not meet typical fire suppression requirements. Fire extinguishing equipment and devices currently in common use do not adequately address the risk of catastrophic damage from large fires or the increased risk to firefighters. In recent years, new types of foam-forming compositions and mechanical equipment have become available for fire extinguishing, but again the fire extinguishing performance has not been significantly improved. For example, while extinguishing agents commonly known as aqueous film-forming foams are commonly applied to Type A or B fires, such foams and other foams provide rapid extinguishing and use of conventional pumping and drainage equipment. It has particular drawbacks regarding the means of application in the case. In a typical foam-forming concentrate, a separate concentrate containing a foam-forming agent, such as a fluorinated surfactant, is directed from a conventional centrifugal pump installed on a fire engine into one of a number of drainage lines. The metering device to obtain the desired concentration of foam-forming concentrate delivered from the supply tank to the drain line must be accurate enough to provide the desired concentration of foam-forming composition.
Also, a similar metering device and eductor must be provided for each drainage line.
These accessories substantially increase the cost of the fire extinguishing system and take up the useful space of the fire engine, and more importantly, such devices do not allow the extinguishing fluid to be pumped in order to reduce the pump pressure and pump capacity for the extinguishing fluid being discharged. Limit the distance that can be emitted. Other firefighting foam compositions are known that utilize as additives various nonionic surfactants that promote emulsification and reduce cost when used in combination with fluorinated surfactants, solvents, and foam stabilizers. be. Examples of such compositions that produce low expansion foams are shown in U.S. Pat.
It is described in specifications No. 3772195 and No. 4090967. The nonionic surfactants described in these patents are useful only in combination with fluorinated surfactants because they do not have sufficient wetting properties alone to wet the surface of combustible organic liquids. It is. Additionally, U.S. Pat. Nos. 3,541,010 and 3,578,590 describe foam compositions formed from mixtures of ethoxylated alkylphenols and solvents as fire extinguishing foams useful in extinguishing Type A and B fires. . The composition consists of a concentrate containing up to 30% water which requires the presence of a solvent to prevent gelling of the non-ionic ethoxylated alkyl phenol, which concentrate is present in the discharge stream from about 0.5% to 30% water.
A foam containing about 6% by volume of the nonionic active agent is formed. In any case, the foam composition as described above is added to the water stream only on the discharge side of the pump. When such foam compositions are added to the discharge stream on the intake side of the pump rather than on the discharge side, excessive foaming can occur causing cavitation of the pump and overall loss of output. Therefore, each foam drain line must be provided with its own metering and delivery device, which effectively limits the number of foam drain lines on the fire engine to only one for each pump. The need for separate dispensing and foam concentrate supplies for each drainage line from the pump is too costly and requires additional space that is not available. Also, the use of a single foam drainage line significantly limits the efficiency of the fire extinguishing system. Another factor considered important in achieving an ideal fire extinguishing system is the volume of extinguishing solution used for extinguishing the fire, which is limited to remote areas where water availability is limited to mobile supply tanks associated with pumping fire engines. It can be a critical element in certain places. Additionally, the use of smaller volumes of fire extinguishing fluid is critical to avoiding significant water damage commonly incurred by property owners during normal firefighting operations. The main object of the present invention is to provide a fire extinguishing composition and a fire extinguishing method that enable fire extinguishers to extinguish fires in a shorter time by making maximum use of conventional fire extinguishing equipment. Another object of the present invention is to provide a fire extinguishing concentrate that can be added to the suction side of a pump without excessive foaming or cavitation of the pump, thereby providing a fire extinguishing solution that is radiated onto the flame; Furthermore, it is an object of the present invention to provide a fire extinguishing solution containing very low concentrations of nonionic surfactants which makes it possible to extinguish fires of types A, B and D more efficiently and economically. The fire extinguishing composition according to the present invention has a cloud point of itself when used alone, and a cloud point of the mixture of 20 to 100 °C (68 to 68 °C) when used in combination of two or more. 212〓) in an aqueous medium at a very low concentration in the range of 0.02 to 0.2% by volume. The fire extinguishing composition is prepared from a concentrated solution of the surfactant as a dilute aqueous solution. This concentrated liquid can be obtained on the fire extinguishing system and used as such without undue foam formation or pump cavitation, for example by adding it into the discharge stream on the suction side of a conventional discharge pump. The cloud point of the surfactant used in the present invention (if two or more types are used in combination, the cloud point of the mixture)
It is a nonionic surfactant whose temperature ranges from 20 to 100°C. In the present invention, the cloud point is ASTMD2042-65
Measurements were made on a 1% by weight nonionic surfactant solution in 100 ml of water according to the test method specified in . If the cloud point of the surfactant (individually or as a mixture) is lower than 20°C, it will not be sufficiently soluble and will lack usefulness. On the other hand, if the cloud point is higher than 100℃, the fire extinguishing ability will be lost. However, even if each surfactant has a cloud point outside of this specified range, two surfactants that when mixed exhibit a cloud point within this range.
Mixtures of more than one nonionic surfactant are sufficiently soluble to be effective for the fire suppression purposes of the present invention. Principal examples of nonionic surfactants useful in the present invention are those obtained by condensation of ethylene oxide or propylene oxide with various compounds, especially side chain-containing phenolic compounds. Such compounds include fatty acids such as stearic acid, lauric acid, palmitic acid, etc.; aliphatic alcohols such as mannite, sorbitol, etc.; primary and secondary fatty acids such as ethanol, isopropanol, isobutanol, etc.
or tertiary alcohols; aliphatic amines or amides and alkylolamines. molecular weight
Also useful as nonionic surfactants are block copolymers of ethylene oxide and propylene oxide having a molecular weight of 1,100 to 15,500 and oxypropyleneoxyethylene polyols derived from ethylene diamine. Particularly useful surfactants are those obtained by the condensation of ethylene oxide and alkylphenols, where the alkyl group of the alkylphenol can have from 1 to 12 carbon atoms, but especially from 6 to 9 carbon atoms. Preferred are octyl, nonyl and the like. A mixture of two or more surfactants has a cloud point of 20~
It is selected to be water soluble within a range of 100°C and to produce a minimum amount of foam. In surfactants derived from ethylene oxide, the amount of ethylene oxide molecules can be up to 40 mol%, preferably from 1.5 to 9 mol%. In the practice of this invention, the concentrate contains less than 30% by weight nonionic surfactant, preferably 20-29% by weight. If the amount of surfactant is greater than this and its concentration in water is higher than 30% by weight, the surfactant will form a gel and become unsuitable for use. It is therefore necessary to keep the concentration of nonionic surfactant in the concentrate at a maximum of 30% by weight. It is this concentrate that is used by firefighters in storage or supply tanks on the fire engine. This concentrate, when kept in a storage tank at a concentration of up to 30% by weight, can be used as is to provide the fire extinguishing composition of the present invention when required. From this storage tank, the concentrate is fed to the suction side of a conventional pump whose respective drain lines direct a liquid stream toward the flame. Of course, this concentrated liquid can be mixed with water in advance and then sent to the suction side of the pump and discharged from the drain line. The concentrated liquid does not need to be sent to the nozzle of the drainage line, but can be introduced into the water suction side of the pump. This allows mixing and preparation of the extinguishing solution to take place on the suction side of the pump, so that the flow of extinguishing solution from each drain line is distributed without excessive foaming or cavitation that could cause overheating and damage to the pump. can be done. Also,
The previously required delivery and metering devices on each drainage line are avoided, resulting in improved costs and space on the fire engine. Therefore, fire pumps are not limited to a single type of drainage line, but are rich in diversity. To use the concentrates described above, conventional delivery or metering means are provided on the suction side of a conventional pump. The capacity of the pump installed in a normal pump fire engine is approximately 946/
min, 1893/min, 2839/min, 3785/min, 4732
/min, 5678/min (250, 500, 750, 1000, 1250, respectively in gallons per minute (gpm))
(equivalent to 1500gpm) etc. Capacity approx. 5678/
(1500 gpm) pumps typically have approximately 946
There are six drainage lines approximately 6.4 cm (2.5 inches) each with a capacity of 250 gpm (250 gpm). Traditionally, when a delivery device is used to deliver fire extinguishing composition to a drainage line, the pipe size is approximately 3.8 cm.
(1.5 inches) [capacity approximately 379/min (100 gpm)]. The provision of a dispensing metering device therefore reduces the versatility of the pump fire engine, since only this special line is useful for foam-forming spraying. In contrast, according to the present invention, it takes approximately 6.4 cm to emit extinguishing solution at a given pump volume.
Six (2.5 inch) drainage lines can be used. A fire extinguishing solution is prepared from the above concentrate such that the fire extinguishing solution contains 0.02 to 0.2% by volume of nonionic surfactant. Preferably the extinguishing solution contains a surfactant.
Contained at a concentration of 0.03-0.1% by volume. The concentration of surfactant in the extinguishing solution is important in extinguishing the fire very quickly. It has been found that by using surfactants at the low concentrations defined in this invention, a fire can be completely surrounded or shielded by the cloud resulting from the extinguishing solution. Thus, according to the invention, fires are extinguished more quickly than with conventional fire extinguishing compositions. A low concentration of nonionic surfactant in the extinguishing solution is also important because it allows the extinguishing solution to be pumped without excessive foam or pump cavitation that would damage the pump or limit the reach of the water flow. be. To demonstrate the importance of keeping surfactant concentrations below 0.2% by volume, approximately 1893 (500
A comparative test was conducted for use in a fire engine (Gal. gallon).
The nonionic surfactant used was ethylene oxide 9
The molar proportion of nonylphenol ethoxylate was added to the water stream at a concentration of 0.3% by volume of nonionic surfactant, and the mixture was delivered through a standard nozzle set at about 227/min (60 cal/min). When this mixture was introduced into the water suction side of the pump and emitted, the maximum distance was approximately 16.8 ~
18.3 m (55-60 ft), whereas using compositions of the present invention containing up to 0.2% by volume of freshwater or nonionic surfactants in water, the radiation distance was approximately 25 m (82 ft). It was hot. The results reveal that when conventional compositions are used, foam is generated, which causes a decrease in pump pressure that shortens the radiation distance. In order to further clarify the differences between the compositions of the present invention and conventional compositions, the above nonionic surfactant solution is discharged by means of a conventional bypass valve by closing the hose nozzle, as is done in some cases when extinguishing a fire. When circulated into the feed tank, the pump began to overheat in 3 minutes due to foam generated in the pump. The pump also became unusable due to cavitation. Reopen the nozzle and increase the flow rate to approximately 227
/ minute (60 gallons/minute), about 7.6 ~
A discharge of water of 12.2 m (25 to 40 ft) occurred, but
This water discharge was not continuous, but tended to occur suddenly. After all the water was drained from the tank, the tank gauge still showed full, but when the tank was inspected, it was filled with fine bubbles (this is why the tank gauge was showing full). . This foam impeded operations and made it impossible to refill the tanks. Next, the present invention will be further explained with reference to Examples, but the present invention is not limited to these Examples in any way. Examples 1 and 2 were made by weight of 74% water, 21.0% nonylphenoxy polyethoxyethanol with 9 mol% ethylene oxide, and 3 mol% ethylene oxide.
and a condensate of 9 mol% ethylene oxide, a nonylphenoxypolyethoxyethanol block polymer [molecular weight 2900, cloud point approx.
58°C (136〓)] from a concentrate consisting of 4.0%, 0.8% of a corrosion inhibitor such as sodium nitrate and boric acid amide (boric acid + monoethanolamine) and 0.2% of a biocide such as sodium 1-hydroxypyridine-2-thione. A fire extinguishing composition of the present invention was prepared. The corrosion inhibitor may be any conventional one, but suitably from 0.1 to 3% by weight of sodium nitrate to boric acid amide in a weight ratio of 2:1 to 1:2. Biocides can be blended in an amount of 0.001 to 1% by weight, including sodium omazine (trade name of 1-hydroxypyridine-2-thione sodium salt manufactured by Olin), Proxel CRL (1,2-benzine manufactured by ICI, USA), (trade name of isothiazolin-3-one), Kathon 886 (manufactured by Rohm and Haas)
-Chloro-2-methyl-4-isothiazoline-3
(trade name of a mixture of 8.6% of 1-one and 2.6% of 2-methyl-4-isothiazolin-3-one) or the like may be blended. The cloud point of the above mixture was approximately 58.5°C (137°). Approximately 3.785 (1 gallon) of the above concentrate was premixed with approximately 1893 (500 gallons) of water before being pumped into the suction side of the pump. This gives 0.2% by volume of the concentrate or 0.05% by volume of non-ionic surfactant in the fire extinguishing fluid. Example 1 No. 2 was inserted into a test hole approximately 3 m (10 ft) in diameter.
Pour approximately 340 (90 gallons) of fuel oil, ignite it, and
Burned for minutes. This flame was extinguished using a commercially available wetting agent in extinguishing water, and two pump lines with a water discharge rate of approximately 379/min (100 gallons/min) were used to extinguish the flame.
The fire was extinguished in 90 seconds. Water and wetting agent consumption is approximately 1136
(300 gallons). Clean the above hole and use No. 2 fuel oil again with approximately 340 ml of No. 2 fuel oil.
(90 gallons) and burned for 2 minutes. When using the above-mentioned fire extinguishing solution of the present invention, extinguishing
It finished in 20 seconds. This solution is pumped at approximately 87/min (23 gal/min) using one booster pump line.
of the flame without excessive foaming or cavitation. The amount of extinguishing solution required to extinguish the fire was approximately 30.3 (8 gallons), which corresponds to approximately 0.06 (0.016 gallons) of concentrate consumption. Example 2 Using wood as combustible material, approximately 45.4 kg of wood
(100 lbs.) was treated with gasoline, ignited, and allowed to burn for 4 minutes before being extinguished. The wood fire was extinguished using a booster pump line with a water discharge rate of approximately 87/min (23 gallons/min) and took 72 seconds to extinguish. Another pile of 100 pounds of wood was similarly ignited and allowed to burn for 4 minutes. When a fire was extinguished by a booster pump line using water containing the fire extinguishing solution of the present invention described above at a water discharge rate of approximately 87 gallons per minute (23 gallons per minute), the fire was extinguished in 11 seconds without excessive foam or cavitation. did. Examples 3-7 below all contain 74% water by weight.
%, 23.5% nonylphenoxypolyethyleneoxyethanol with 9 mol% ethylene oxide, 1.5% nonylphenoxypolyethyleneoxyethanol with 1.5 mol% ethylene oxide, and Examples 1-
The same corrosion inhibitor and 1% biocide concentrate as in Example 2 were tested. The cloud point of this concentrate is approximately 33
It was ℃ (92〓). Approximately 3.785 (1 gallon) of this concentrate was premixed with approximately 1893 (500 gallons) of water to form a fire extinguishing solution containing 0.05% by volume surfactant before being delivered to the intake side of the pump. Example 3 50/50 fuel mixture of No. 2 fuel oil and gasoline approx.
473 (125 gallons) was ignited in a 12 foot diameter test hole and allowed to burn for 2 minutes. This was first done using commercially available AFFF foam.
When the fire was extinguished using a foam nozzle, the 6%
The fire was extinguished in 31 seconds by discharging AFFF solution at approximately 379/min (100 gal/min). Thus, the amount of AFFF solution used is approximately 193 (51 gallons), which corresponds to the consumption of approximately 11.6 (30.6 gallons) of AFFF foam. Clean the hole above and reapply the fuel mixture to approx.
473 (125 gallons) was charged and burned for 2 minutes. When the above-mentioned fire extinguishing solution of the present invention was used, extinguishing was completed in 28 seconds. This solution is pumped at approximately 87/min (23 gal/min) using one booster pump line.
minutes) into the flame. Therefore, the amount of extinguishing solution required to extinguish the fire was only about 41.6 (11 gallons), which corresponds to a concentrate consumption of about 0.08 (0.022 gallons). Example 4 Two piles of tires, each consisting of 200 tires, were ignited with approximately 5 gallons of a mixture of gasoline and motor oil and allowed to burn for 6 minutes. This time was sufficient to generate extremely high heat and spread the flames throughout the mountain. About 1893 to the first mountain
(500 gallons) 1 pump to 2 booster lines
Approximately 114/min (30 gallons/min) of fresh water depending on the system
radiated at a speed of The tank was emptied in eight minutes, but the fire was still not extinguished. The fire extinguishing solution of the present invention described above was applied to the second mountain at a rate of approximately 114 gallons per minute (30 gallons per minute) through one booster line, and the fire was completely extinguished in two minutes. The amount of extinguishing solution used is only approx.
227 (60 gallons), which corresponds to approximately 0.45 (0.12 gallons) of concentrate consumption. Example 5 Approximately 6.8 Kg (15 lbs) of magnesium was
It ignited with 36.3 Kg (80 lb) and burned for 5.5 minutes before being extinguished. When water was sprayed from a single hose at a rate of approximately 114/min (30 gallons/min), it took 12 minutes to extinguish the fire. The extinguishing solution of the present invention described above was applied to a similarly burned magnesium flame at approximately 87/min (23 gallons/min).
The fire was extinguished in 2.5 minutes without excessive foam or pump cavitation. Example 6 This example demonstrates that the fire extinguishing composition according to the invention has a superior cooling effect compared to water. Approximately 511 (135 gallons: approximately 0.511 m ³ ) of LP gas was used in each test. When the pressure is released, this LP gas expands 2500 times to a volume of approximately 1277.5m ³ . An approximately 946 (250 gallon) LP gas tank was set up so that combustion gas was supplied to the tank through an inlet valve and leaked through an outlet valve at the other end. The temperature of the combustion gas is estimated to be about 1150℃ (2100〓), and the test temperature is about 27~52℃ (80~125〓), which is enough to allow firefighters to close the inlet and outlet valves.
It measures how much time it takes to cool down to a temperature range of . In the first test, water was discharged from two hose lines each at a rate of approximately 473 gallons per minute (125 gallons per minute). The temperature of the tank and valve should be approximately 27-52℃ (80℃).
It took 220 seconds to cool down to ~125〓), and the amount of water used for this cooling was about 3312 (875 gallons). In a second test, another ¹³⁵ gallons of gas was similarly ignited and delivered to a 250 gallon LP gas tank. When about 3.785 (1 gallon) of the concentrated liquid of the present invention described above was mixed with about 1893 (500 gallons) of water on the suction side of the pump and irradiated onto the tank surface at a rate of about 87/min (23 gallon/min), The tank heats up approximately 27-52℃ (80-52℃) in 29 seconds.
125〓). The amount of fire extinguishing solution used to cool the tank was only about 41.6 (11 gallons), which is equivalent to about 0.08 (0.022 gallons) of concentrate. Example 7 Fill a hole approximately 1.8 m x 2.4 m (6 ft x 8 ft) with water to a depth of approximately 10 cm (several inches), add about 57 (15 gallons) of gas oil to the top layer, and ignite it. and burned for 30 seconds. This was extinguished using a commercially available AFFF product pumped through a 6% foam nozzle at a rate of approximately 340 g/min (90 gal/min), and the normally stable foam rapidly dissipated after the extinguishment. The amount of 6% AFFF solution used to extinguish the fire was approximately 85 (22.5 gallons), which is
Equivalent to consumption of approximately 5.1 (1.35 gallons) of AFFF product. In the second test, gas oil was similarly ignited and burned, and the concentrated liquid of the present invention described above was tested at approximately 3.785% (1
The fire was extinguished in 14 seconds using a fire extinguishing solution mixed with approximately 1,893 gallons (500 gallons) of water on the water intake side of the pump. The amount of fire extinguishing solution used is very small, about 20.4 (5.4 gallons), which is equivalent to about 0.04 (0.0108 gallons) of concentrate. Example 8 A concentrated liquid was prepared by replacing the nonionic surfactant with those in the table below in the fire extinguishing agent compositions (concentrated liquid) used in Examples 3 to 7, and these were mixed with water to a concentration of the active agent of 0.2. It was diluted to give % by volume and used by supplying it to the water suction side of the pump. In either case, water could be discharged smoothly from the drainage line without causing cavitation in the pump. The following tests were also conducted to compare the degree of expansion of foam produced by the use of these compositions. 25 ml of the test solution was placed in a 250 ml graduated cylinder with a glass stopper, the cylinder was held upright and shaken vigorously for 10 seconds. 15 bubbles generated
After standing for seconds, the volume of foam (ml) was recorded.
The degree of foam expansion was determined by subtracting 25 ml from the total foam volume and dividing the remaining amount by 25. That is, this quotient indicates the volume of foam expanded beyond a unit amount of the test solution. The test was conducted at approximately 21°C (70°C). In order to determine the relative degree of expansion between the test samples from this result, we arbitrarily determined the foam expansion index (hereinafter referred to as foam expansion index) of the test samples of the present invention shown in the table below that showed the maximum foam expansion. FEI (abbreviated as FEI) is set as 1.0, and the F of each sample is determined based on this value.
The EI was calculated and shown in the table.

【table】

Table: Example 9 FFI of compositions of the invention with various active agent concentrations prepared from the concentrates used in Examples 3-7.
was compared to the FEI of a fire extinguishing foam using a known nonionic surfactant according to the test method of Example 8.
The results are shown in Table 1. The concentrated liquids used for comparison in Table 1 all have a composition by weight of 40% alkyl phenol ethoxylate, 30% ethylene glycol monobutyl ether, and 30% water.

【table】

TABLE The small volume of fire extinguishing solution according to the invention used in the examples above demonstrates that it is useful in more remote locations without using large amounts of water. Additionally, the reduced amount of fire extinguishing solution used represents a significant reduction in water damage compared to conventional fire extinguishing solutions. Considering the above test and other fire extinguishing situations, the following can be said theoretically. That is, the fire extinguishing compositions of the present invention form a film of non-ionic surfactant that is readily vaporized on the flammable mixture at high temperatures, and this vapor expands many times more than when water becomes steam and this Vaporization creates clouds around the flame,
Quickly suppresses flames by inhibiting combustibility of air. This phenomenon of generation of extinguishing vapor exerts a strong cooling effect on combustible surfaces. For example, combustion materials extinguished with the compositions of the present invention can be held in the hand immediately after extinguishing, whereas combustion materials extinguished with water and other higher concentrations of wetting agents are hot to the touch even after extinguishing. I can't. By using the compositions of the present invention, firefighters can quickly enter a building with a Type A, B or D fire and quickly extinguish the fire with a minimum amount of water. It is clear that the efficacy of the compositions according to the invention does not depend on foam. In fact, a test was conducted using an antifoaming agent to prove the usefulness of the present invention as a fire extinguishing agent. The fire extinguishing solution of the present invention is inexpensive, can be used diluted with large amounts of water, can be stored in concentrated liquid form without corrosion, and can be mixed with water before use to form a fire extinguishing fluid without the risk of corrosion. It can also be diluted with hard water, soft water, seawater or salt water, yet provides substantially improved fire extinguishing performance compared to conventional products.

Claims (1)

[Claims] 1. When used alone, the cloud point of itself is in the range of 20 to 100°C, while when used in combination of two or more, the cloud point of the mixture is in the range of 20 to 100°C. A fire extinguishing composition comprising one or more nonionic surfactants in an aqueous medium at a concentration of 0.02 to 0.2% by volume, which is delivered as a liquid stream without excessive foam formation. 2. The composition according to claim 1, wherein the surfactant is selected from alkyl phenoxy polyoxyethylene ethanols. 3. The composition according to claim 2, wherein the alkylphenoxy group is nonylphenol, and the polyoxyethylene group is an ethylene group containing 1.5 to 40 moles of ethylene oxide. 4. The composition according to any one of claims 1 to 3, which contains a biocide and a corrosion inhibitor in addition to the nonionic surfactant. 5 When used alone, the cloud point of itself is within the range of 20 to 100 °C, while when used in combination of two or more, the cloud point of the mixture is in the range of 20 to 100 ° C. A concentrated liquid containing an ionic surfactant and a sufficient amount of water such that the concentration of the surfactant in the concentrated liquid is 30% by weight or less is prepared, and this concentrated liquid is mixed with water to dissolve the surfactant. A method for extinguishing fires, characterized in that an extinguishing solution containing not more than 0.2% by volume is prepared and this extinguishing solution is radiated onto the flame in at least one liquid stream that does not produce excessive foam. 6. The fire extinguishing method according to claim 5, wherein the surfactant is selected from ethoxylated alcohols. 7. The fire extinguishing method according to claim 5, wherein the surfactant is nonylphenoxy polyoxyethylene ethanol containing 1.5 to 40 mol% of ethylene oxide. 8. The fire extinguishing method according to claim 5, wherein the concentrated liquid and water are mixed on the water suction side of the radiation pump. 9 Surfactant at 0.02-0.2% by volume in fire extinguishing solution
The fire extinguishing method according to any one of claims 5 to 8, wherein the fire extinguishing method is present in an amount of . 10. The fire extinguishing method according to any one of claims 5 to 8, wherein a fire extinguishing solution is passed through a pump and is radiated from a plurality of drainage lines to the pump without cavitation. 11. The fire extinguishing method according to claim 10, wherein the surfactant is present in the fire extinguishing solution at a concentration of 0.03 to 0.1% by volume. 12. The fire extinguishing method according to any one of claims 5 to 8, wherein the concentrated liquid contains 20 to 29% by weight of a surfactant. 13 Extinguishing solution contains 0.03-0.1% by volume of surfactant
The concentrated liquid contains surfactants at a concentration of 20 to 29
The fire extinguishing method according to any one of claims 5 to 8, containing % by weight. 14. The fire extinguishing method according to claim 10, wherein the concentrated liquid contains 20 to 29% by weight of a surfactant. 15. The fire extinguishing method according to claim 5, wherein the surfactant is a block copolymer of ethylene oxide and propylene oxide having a molecular weight of 1,100 to 15,500 or an oxypropyleneoxyethylene polyol derived from ethylenediamine.