EP0676220A1 - Compositions for portable extinguishers containing pulverised water for fires of classes A and B - Google Patents

Abstract

A portable water-spray fire extinguisher contg. an anti-fire emulsion. AFFF (aqueous film forming foam), which includes a combustion inhibitor - is claimed. The main ratio of inhibitor to emulsion is 0.5-6.

Description

The present invention relates to the field of fire extinguishing and more particularly relates to portable extinguishers with water spray which can be used to extinguish class B fireplaces (combustible liquids) and class A fireplaces (absorbent solid materials such as fabrics, paper, wood ...).

For extinguishing fires of absorbent or porous materials, it is known to use combustion inhibitor products such as, for example, ammonium phosphates or sulphates, which under the action of heat decompose endothermically. Decreasing the heat energy of the hearth, this decomposition inhibits the chain reaction mechanism of combustion and considerably reduces the emission of combustible gases. The flame retardancy mechanism by ammonium phosphates and sulfates has been described by S. SZONYI and A. CAMBON in the General Safety Review n ° 92, March 1990, pages 68-76, as well as in the work entitled " Extinguishing agents that inhibit the atmosphere and inerting gas "from the National Center for Prevention and Protection, 1982, chapter 3, pages 79-129.

Combustion inhibitor products are used in particular in aqueous solution or dispersion for extinguishing forest fires (long-term retardants). They are also used in the composition of many combustion inhibitor liquids for absorbent materials (US Patents 2,569,714, US 3,293,189, US 4,447,336, US 4,606,831, US 4,983,326, US 3,558,486, US 4,272 414, DE 2 724 162, DE 3 735 707, BE 895 993, BE 721 816, FR 2 019 890, FR 2 663 945 and DE 2 921 306.

Used in solid form, phosphates and ammonium sulphates also constitute the basic elements of ABC extinguishing powders such as those described in the patents DE 1 233 276, DE 1 542 506, DE 1 621 718, DE 2 635 351, DE 2,902,948, DE 3,321,174, DE 4,136,398, GB 1,410,469 and FR 1,510,555. US Pat. No. 3,553,127 describes the use of an extinguishing powder, the constituents of which (inorganic salts) are impregnated with 'a fluorinated surfactant to increase the resistance of the powder to re-ignition.

où

CE

= coefficient d'étalement en mN/m

γ_HC

= tension superficielle de l'hydrocarbure

γ_s

= tension superficielle de la composition extinctrice après dilution de l'émulseur

γ_i

= tension interfaciale entre l'hydrocarbure et la composition extinctrice après dilution de l'émulseur

One of the well-known means for extinguishing fires of hydrocarbon liquids consists in projecting onto the hearth a foam obtained by mixing water under high pressure and an emulsifier based on hydrocarbon surfactants and surfactants. fluorinated active ingredients. In this latter type of foam concentrate, known in the art as AFFF (Aqueous Film-Forming Foam) foam concentrates, the presence of the fluorinated surfactant makes it possible to produce a foam which, by decantation, forms an aqueous film floating on the surface of the hydrocarbon. . This watery film not only aims to extinguish the fire, but also to prevent a possible re-ignition of the surface of the oil. Foam concentrates of this type have been described in numerous patents, in particular the following: GB 1 258 299, US 5 085 786, FR 2 347 426, US 3 957 657, FR 2 040 316, US 4 350 206, FR 3 562 156, FR 2 148 442, FR 2 407 724, FR 2 385 413, US 3 772 195, FR 2 397 847, US 3 661 776, US 3 839 425, FR 2 103 669, US 3 957 657, US 3 963 776 and FR 2 296 625. AFFF foam concentrates produce, after dilution with water and addition of air, a foam forming, by decantation, an aqueous film which spreads over the entire surface of the hydrocarbon. The thermodynamic equilibrium condition necessary to form the aqueous film is linked to the spreading coefficient (CE) which must be positive: $${\text{CE = γ}}_{\text{HC}}{\text{- (γ}}_{\text{s}}{\text{+ γ}}_{\text{i}}\text{)}$$

or

THIS

= spreading coefficient in mN / m

γ _HC

= surface tension of the hydrocarbon

γ _s

= surface tension of the extinguishing composition after dilution of the foam concentrate

γ _i

= interfacial tension between the hydrocarbon and the extinguishing composition after dilution of the foam concentrate

In a portable fire extinguisher, the amount of water available to dilute the foam concentrate to the use concentration (0.5 to 6%, most often 1 to 3%) is limited and generally set at 6 or 9 liters , while in the application system by means of a lance the quantity of water available is not limited. It is for this reason that foam concentrates for portable fire extinguishers are more concentrated in active materials and therefore more efficient. For example, to obtain the certification of a 6 liter extinguisher for type 144 B fires, the portable extinguisher must extinguish with only 6 liters of foam concentrate solution diluted to 3% (French standard) S61-900), while in the case of extinction with a fire hose the maximum available quantity of foam concentrate solution diluted to 3% may be up to 28.5 liters (French standard S60-220) or 22 , 3 liters (UL 162 standard).

The characteristics of fire extinguishers and the multiple tests which they must satisfy are defined in French standard S 61-900 and the draft European standard EN 3. A fire extinguisher is a device containing an extinguishing agent which can be projected and directed on a fire by the action of an internal pressure, this pressure being able to be provided by a permanent preliminary compression or to be obtained by a chemical reaction or the release of an auxiliary gas. A portable fire extinguisher is a fire extinguisher which is designed to be carried and used by hand and which, in working order, has a mass less than or equal to 20 kg. The load of water-based devices is expressed in volume (liters). In practice, the costs of portable extinguishers with water spray with additive the most common are 6 and 9 liters. Today the vast majority of additives are constituted by an aqueous film-forming solution of the AFFF type effective on class B fires; their effectiveness on class A solid material fires is greater than that of a portable water extinguisher without additives. This increased efficiency on class A fires is due to the presence of fluorinated and non-fluorinated surfactants which increase the wetting power of water and allow it to better coat and penetrate the fibers of solid materials such as fabrics, paper, wood. Over time, many innovations have made it possible to obtain portable fire extinguishers that are more efficient or more practical to use. For example, the confinement of surfactants in solid form which give a film-forming solution by dissolution in the stream of water supplied from the reservoir is described in patent FR 2 458 294. Patent FR 2 662 608 relates to use of a frangible cartridge pressurized at the time of use by a compressed gas; the cartridge not being attached to the extinguisher is therefore compatible with any type of auxiliary pressure extinguisher. Various other technical improvements are described in patents EP 507664, EP 507665, EP 298022, EP 112950, FR 2 505 970, FR 2 264 567, GB 1 349 969, FR 2 670 389, FR 2 598 923.

However, in extinguishers containing an AFFF foam concentrate as described above, even if the extinguishing efficiency of AFFF solutions on class A fires is greater than that of water alone, it remains limited. Indeed, for the extinction of class A type fireplaces, standardization considers extinction as successful if there is no flame recovery during the 5 minutes (standard NF S61-900) and the 3 minutes ( draft standard EN 3) which follow the discharge of the extinguisher. The additive AFFF used alone has only a physical action of suffocation, wetting and cooling during the extinction; under the effect of heat, the evaporation of the water constituting the foam releases the surface-active agents in solid form, the latter being devoid of any flame-retardant action on the wood. As a result, the presence of glowing embers may be responsible for a resumption of flames and cause the extinction test to fail.

The problem of extinguishing standard class A fires is particularly crucial in the context of the draft European standard EN 3 which is increasingly demanded by users compared to national standards. A person skilled in the art recognizes without ambiguity the difficulty represented by the extinction of a type A class household according to the draft European standard compared to the household referenced in the same way but according to French standard; by its construction, its arrangement and its volume, a 21 A fireplace according to the draft European standard is much more difficult to extinguish than a 21 A fireplace according to the French standard. Although the project of European standard stipulates minimum requirements for extinguishing class A fireplaces according to the capacity of the extinguisher, extinguisher manufacturers are still looking for solutions allowing them to exceed these minimum requirements in the case of portable fire extinguishers. water spray.

It has now been found that this problem can be solved by combining with the AFFF foam concentrate a combustion inhibitor product which increases the extinguishing performance on a class A hearth, while preserving the performance of the class B hearth foaming agent. .

The subject of the invention is therefore a portable extinguisher with water spray containing an AFFF fire-fighting foam concentrate, characterized in that it also contains a combustion inhibitor, the mass ratio of the inhibitor to the foam concentrate being between 0 , 5 and 6, preferably between 1 and 4.

According to the invention, for 100 parts of water contained in the portable fire extinguisher, use is made of 0.5 to 6 parts by weight (preferably 1 to 3 parts) of foam concentrate and from 1 to 20 parts by weight (of preferably 2 to 8 parts) of combustion inhibitor.

• a) l'émulseur ou l'inhibiteur est placé dans une cartouche à opercule, l'autre constituant étant prémélangé avec l'eau de l'extincteur ;
• b) l'émulseur et l'inhibiteur sont placés séparément chacun dans une cartouche à opercule ;
• c) l'émulseur et l'inhibiteur sont placés tous deux dans une seule cartouche à opercule.

The AFFF foam concentrate and the combustion inhibitor are used together in a conventional portable water spray fire extinguisher. They can both be there in premix with the water from the extinguisher, but also separately according to one or the other of the following methods:

• a) the foam concentrate or the inhibitor is placed in a cartridge with a cover, the other constituent being premixed with the water from the fire extinguisher;
• b) the foam concentrate and the inhibitor are each placed separately in a cover cartridge;
• c) the foam concentrate and the inhibitor are both placed in a single cartridge cartridge.

In all cases, the foam concentrate and the inhibitor are mixed with the water contained in the extinguisher at the time of use. Under the effect of pressure, the mixture, that is to say the extinguishing composition, is expelled outside the body of the extinguisher and, by passing through the sprayer, forms a foam capable of extinguishing both class B fires (combustible liquids) and class A fires (absorbent materials).

In the context of the present invention, any of the known combustion inhibitors or a mixture of such inhibitors can be used. As nonlimiting examples of combustion inhibitor compounds, mention may be made of mono-, di- or tri-ammonium orthophosphates, mono-, di-, tri- or tetra-ammonium pyrophosphates, ammonium metaphosphate, polyphosphate ammonium, mixed salts of alkali metal ions and ammonium-orthophosphate, -pyrophosphate or -polyphosphate, and ammonium sulfate and bisulfate. We prefer use ammonium orthophosphates and sulphates, in particular mono-ammonium orthophosphate, di-ammonium orthophosphate and ammonium sulphate or mixtures of these compounds.

• un agent antigel comme l'éthylène glycol ou le propylèneglycol,
• un anticorrosif tel que le tolyltriazole ou le nitrite de sodium,
• un conservateur tel que le benzoate de sodium, le formaldéhyde, I'o-phénylphénol ou le dichlorophène,
• un stabilisateur de pH tel que l'ammoniaque, la diéthanolamine, la triéthanolamine ou l'urée.

In the context of the present invention, any known AFFF foam concentrate can be used comprising in aqueous or hydroalcoholic solution at least one fluorinated surfactant, at least one non-fluorinated surfactant, and at least one co-solvent such than a monoalkyl ether of mono- or di-ethylene (or propylene) glycol. Preferably, an emulsifier is used whose content by weight of fluorinated surfactant (s) is between 5 and 25%, advantageously between 7 and 18%, that of surfactant (s) non-fluorinated active (s) ranging from 2 to 20%, preferably between 4 and 18%, and that of co-solvent being able to range from 20 to 50%, preferably from 30 to 45%. The foam concentrate can also contain various additives such as:

• an antifreeze agent such as ethylene glycol or propylene glycol,
• an anticorrosive such as tolyltriazole or sodium nitrite,
• a preservative such as sodium benzoate, formaldehyde, o-phenylphenol or dichlorophene,
• a pH stabilizer such as ammonia, diethanolamine, triethanolamine or urea.

dans lesquelles :

• R_F représente un radical perfluoroalkyle, linéaire ou ramifié, contenant au moins 6 atomes de carbone, de préférence de 6 à 16 atomes de carbone ;
• m est un nombre entier allant de 0 à 6, de préférence égal à 0 ou 2 ;
• X désigne un groupe CO ou SO₂, de préférence un groupe SO₂ ;
• R représente un atome d'hydrogène ou un radical méthyle ou éthyle ;
• n est un nombre entier allant de 1 à 5, de préférence égal à 3 ;
• R¹ et R², identiques ou différents, représentent chacun un radical méthyle ou éthyle ;
• p est un nombre entier allant de 1 à 5, de préférence égal à 1, 2 ou 3 ; et
• Y^⊖ désigne un groupement SO₃^⊖, OSO₃^⊖ ou COO^⊖.

As nonlimiting examples of fluorinated surfactants which can be used in the foam concentrate, mention may be made of the compounds of general formulas (I) and (II):

in which :

• R _F represents a perfluoroalkyl radical, linear or branched, containing at least 6 carbon atoms, preferably from 6 to 16 carbon atoms;
• m is an integer ranging from 0 to 6, preferably equal to 0 or 2;
• X denotes a CO or SO₂ group, preferably an SO₂ group;
• R represents a hydrogen atom or a methyl or ethyl radical;
• n is an integer ranging from 1 to 5, preferably equal to 3;
• R¹ and R², identical or different, each represent a methyl or ethyl radical;
• p is an integer ranging from 1 to 5, preferably equal to 1, 2 or 3; and
• Y ^⊖ denotes a group SO₃ ^⊖ , OSO₃ ^⊖ or COO ^⊖ .

$$\text{C₆F₁₃-CH₂CH₂-SO₂NH-CH₂CH₂CH₂-N(CH₃)₂ → O}$$

$$\text{C₈F₁₇-CH₂CH₂-SO₂NH-CH₂CH₂CH₂-N(CH₃)₂ → O}$$

$$\text{C₆F₁₃-CH₂CH₂-SO₂N(CH₃)-CH₂CH₂CH₂-N(CH₃)₂ → O}$$

ainsi que les mélanges de bétaïnes de formule :

les mélanges de sulfobétaïnes de formule :

et les mélanges d'oxydes de formule : $${\text{C}}_{\text{x}}{\text{F}}_{\text{2x+1}}{\text{-CH₂CH₂-SO₂NH-CH₂CH₂CH₂-N(CH₃)₂ →}}_{\text{O}}$$

formules dans lesquelles x est un nombre entier pair allant de 6 à 16, la teneur du mélange en composé à radical C₆F₁₃ étant d'au moins 50 % en poids.Fluorinated surfactants, more particularly preferred for the implementation of the present invention, are those of formulas:

$$\text{C₆F₁₃-CH₂CH₂-SO₂NH-CH₂CH₂CH₂-N (CH₃) ₂ → O}$$

$$\text{C₈F₁₇-CH₂CH₂-SO₂NH-CH₂CH₂CH₂-N (CH₃) ₂ → O}$$

$$\text{C₆F₁₃-CH₂CH₂-SO₂N (CH₃) -CH₂CH₂CH₂-N (CH₃) ₂ → O}$$

as well as the betaine mixtures of formula:

mixtures of sulfobetaines of formula:

and mixtures of oxides of formula: $${\text{VS}}_{\text{x}}{\text{F}}_{\text{2x + 1}}{\text{-CH₂CH₂-SO₂NH-CH₂CH₂CH₂-N (CH₃) ₂ →}}_{\text{O}}$$

formulas in which x is an even integer ranging from 6 to 16, the content of the mixture of compound with radical C₆F₁₃ being at least 50% by weight.

        R_H-CONH-C₂H₄-NH-C₂H₄OC₂H₄COOM



        R_H-NH-C₂H₄-COOH



        R_H-N(C₂H₄COOM)₂

$${\text{R}}_{\text{H}}\text{-N(CH₃)₂ → O}$$

dans lesquelles R_H représente un radical alkyle, linéaire ou ramifié, contenant de 8 à 18 atomes de carbone, q est un nombre entier allant de 1 à 16, C₆H₁₀O₅ désigne un groupement glucoside, r est un nombre entier allant de 1 à 6, de préférence égal à 1 ou 2, et M désigne un ion métallique alcalin.The non-fluorinated surfactants usable in the foam concentrate can be anionic, nonionic or amphoteric compounds. By way of non-limiting example, the compounds of the following formulas can be mentioned:

R _H -OSO₃M



R _H - (OC₂H₄) _q -OSO₃M



R _H (OC₂H₄) _q -OH



H (C₆H₁₀O₅) _r -OR _H

R _H -CONH-C₂H₄-NH-C₂H₄OC₂H₄COOM



R _H -NH-C₂H₄-COOH



R _H -N (C₂H₄COOM) ₂

$${\text{R}}_{\text{H}}\text{-N (CH₃) ₂ → O}$$

in which R _H represents an alkyl radical, linear or branched, containing from 8 to 18 carbon atoms, q is an integer ranging from 1 to 16, C₆H₁₀O₅ denotes a glucoside group, r is an integer ranging from 1 to 6, preferably equal to 1 or 2, and M denotes an alkali metal ion.

As nonlimiting examples of co-solvents, mention may be made of monoalkyl ethers such as monoethyl or monobutyl ether of ethylene glycol and monobutyl ether of diethylene glycol.

The performance of the extinguishing compositions according to the invention can be evaluated by means of the following tests:

Spreading

The overrun (or expansion rate) is the ratio of the volume of foam produced from an extinguishing composition to the initial volume. To determine the expansion, we introduce into a test tube of 1 liter 100 ml of extinguishing composition, then the solution is beaten for one minute at the rate of one beat per second using a circular perforated piston (30 holes of 5 mm diameter representing 25% of the surface) and fixed in its center to a metal rod. The expansion must be at least equal to 6, preferably at least equal to 7.5.

Spreading test

This test, which indicates the rate of formation of the aqueous film on the surface of the hydrocarbon, is carried out by pouring 50 ml of hydrocarbon (heptane) into a Petri dish (diameter: 11.5 cm), the outer face of which is painted in black so that you can watch the film. When the surface is stationary, 0.1 ml of extinguishing composition is deposited using a micropipette. The solution should be applied dropwise starting from the center and making an eccentric movement. The stopwatch is started when the first drop is deposited and stopped when the film has covered the entire surface of the hydrocarbon. We note the time. If the total recovery is not obtained in less than a minute, the percentage of surface covered after one minute is noted.

The spreading is satisfactory if the total covering of the surface is obtained in less than 50 seconds, preferably between 20 and 45 seconds.

Thermal resistance test

The evaluation of the thermal resistance of the aqueous film is obtained by measuring the Limit Temperature of Film Stability (TLSF). This test, which can only be carried out if the entire surface of the hydrocarbon is covered by the film, is carried out in a brass measuring container with a diameter of 6.5 cm and a total volume. 100 ml, placed on a thermostated heating plate. In this container, 80 ml of hydrocarbon (heptane) are poured and, when the surface is stationary, 0.1 ml of extinguishing composition is deposited therein as indicated for the test spreading. After 60 seconds, the end of a thermometer is placed in contact with the aqueous film and a flame about 1 cm above the film. The thermostat is set for a temperature increase of 4 ° C / min. The temperature (TLSF) at which the ignition of the hydrocarbon occurs is noted.

A good extinguishing composition must lead to a TLSF higher than 35 ° C, preferably higher than around 40 ° C

Surface and interfacial tensions

The surface tension (γ _s ) with tap water and the interfacial tension (γ _i ) with heptane are measured using a LAUDA tensiometer in accordance with ISO 304 and ISO 6889, but operating at 25 ° C .

In the following examples which illustrate the invention without limiting it, the parts and the percentages indicated are expressed by weight

EXAMPLE 1

- 15,8 parties d'une solution aqueuse à 50 % d'alkyl (C₈ et C₁₀) amidoéther propionate de formule :

        Alkyl-CONH-CH₂CH₂-NH-CH₂CH₂-OCH₂CH₂COONa

(Rewoteric AMVSFcommercialisé par la Société REWO).
- 4,7 parties d'une solution aqueuse à 70 % d'alkyl (C₈ et C₁₀) -glucoside (Triton BG 10 commercialisé par la Société UNION CARBIDE), et
- 40 parties de mono-n.butyléther du diéthylèneglycol (C₄H₉O-C₂H₄-O-C₂H₄OH)At 40 ° C. and with moderate stirring, the following constituents are mixed:
- 24 parts of a 45% aqueous solution of a mixture of fluorinated betaines of formula:

C _x F _{2x + 1} CH₂CH₂-SO₂NH-CH₂CH₂CH₂-N ^⊕ (CH₃) ₂CH₂COO ^⊖

having the following weight composition: x % 6 70 8 23 10 5 12 1.5 14 0.4 16 0.1
- 15.5 parts of a hydroalcoholic solution (35% ethanol) with 40% fluorinated amine oxide of formula: $$\text{C₆F₁₃-CH₂CH₂-SO₂NH-CH₂CH₂CH₂-N (CH₃) ₂ → 0}$$

- 15.8 parts of a 50% aqueous solution of alkyl (C₈ and C₁₀) amidoether propionate of formula:

Alkyl-CONH-CH₂CH₂-NH-CH₂CH₂-OCH₂CH₂COONa

(Rewoteric AMVSF marketed by REWO).
4.7 parts of a 70% aqueous solution of alkyl (C₈ and C₁₀) -glucoside (Triton BG 10 sold by the company UNION CARBIDE), and
- 40 parts of diethylene glycol mono-n.butyl ether (C₄H₉O-C₂H₄-O-C₂H₄OH)

The mixture is then brought to pH 9.3 by addition of diethanolamine. The foam concentrate is thus obtained.

• · foisonnement   : 7,7
• · étalement   : 40 secondes
• · TLSF   : 62°C
• · tension superficielle   : 15,7 mN/m
• · tension interfaciale   : 1,7 mN/m
• · coefficient d'étalement (CE)   : 2,6 mN/m

By mixing 2 parts of this foam concentrate and 6.5 parts of diammonium phosphate (DAP) in 93.5 parts of tap water, an extinguishing composition according to the invention is obtained which has the following characteristics:

• · Expansion: 7.7
• Spreading: 40 seconds
• TLSF: 62 ° C
• Surface tension: 15.7 mN / m
• Interfacial tension: 1.7 mN / m
• · Spreading coefficient (CE): 2.6 mN / m

EXAMPLES 2 TO 6

Example 1 is repeated, but the relative proportions of emulsifier and DAP are modified to prepare five extinguishing compositions, the constitution and characteristics of which are given in the following table: EXAMPLE 2 3 4 5 6 Extinguishing composition consisting of: (parts by weight) - DAP 3.3 5 6.5 5 3.3 - Foam concentrate 2 2 3 3 3 - City water 96.7 95 93.5 95 96.7 Characteristics of the extinguishing composition: - spread (s) 36 33 35 30 25 - TLSF (° C) 51 55 60 58 47 - profusion 7.5 7.6 8.5 9 9.7

EXAMPLE 7

(Deriphat 160C commercialisé par la Société HENKEL).The procedure is as in Example 1, but in the preparation of the foam concentrate, the 15.8 parts of alkylamidoether propionate solution are replaced by 26.3 parts of a 30% aqueous solution of N-lauryl-β-iminodipropionate of formula:

(Deriphat 160C sold by the company HENKEL).

• · foisonnement   : 8,1
• · étalement   : 30 secondes
• · TLSF   : 56°C

The extinguishing composition has the following characteristics:

• · Expansion: 8.1
• Spreading: 30 seconds
• TLSF: 56 ° C

EXAMPLE 8

The procedure is as in Example 1, but in the preparation of the foam concentrate, 6.7 parts of 42% aqueous solution of sodium octyl sulfate (anionic non-fluorinated surfactant sold by the company HENKEL under the name Texapon) are added. 842).

• · foisonnement   : 8,5
• · étalement   : 44 secondes
• · TLSF   : 45°C

By mixing 2 parts of the foam concentrate thus obtained and 5 parts of DAP in 95 parts of tap water, an extinguishant composition according to the invention is obtained having the following characteristics:

• · Expansion: 8.5
• Spreading: 44 seconds
• TLSF: 45 ° C

EXAMPLE 9 (Comparative)

• · foisonnement   : 4,5
• · étalement   : < 10 % après 1 minute
• · TLSF   : non mesurable

By mixing 1 part of the foam concentrate of Example 1 with 8 parts of DAP and 92 parts of city water, an extinguishing composition is prepared which is not in accordance with the present invention (mass ratio: DAP / foam concentrate greater than 6) which has the following characteristics:

• · Expansion: 4.5
• Spreading: <10% after 1 minute
• TLSF: not measurable

The too high DAP / emulsifier ratio results in a fall in film-forming properties and the loss of AFFF properties of the extinguishing composition.

EXAMPLES 10 TO 13

To test the extinguishing efficiency according to the draft European standard EN 3 relating to Portable Fire Extinguishers, portable fire extinguishers of 6 and 9 liters are used containing a cartridge cartridge in which the foam concentrate described in Example 1 is introduced. The combustion inhibitor (DAP) is diluted in water contained in the extinguisher, the total volume of the diluted solution corresponding to the capacity (6 or 9 liters) of the extinguisher.

The following table indicates the performances obtained on class B fireplaces (draft standard EN 3), the fuel being heptane, as well as the minimum requirements. Example Fire extinguisher capacity (l) Amounts used Fireplace Type Tested Obtaining extinction Minimum requirement (EN3) DAP (g) Foam concentrate (ml) 10 6 200 180 144B Yes 113B 11 9 300 180 233B Yes 183B 12 9 400 180 233B Yes 183B 13 9 600 270 233B Yes 183B

The extinguishing compositions according to the invention make it possible to extinguish typical class B fireplaces of size greater than that of the minimum requirements.

EXAMPLES 14 TO 16

The application of the extinguishing compositions according to the invention was tested on class A fireplaces according to the draft European standard EN 3 using a 9 liter portable extinguisher. As in the previous examples, the foam concentrate of Example 1 is introduced into the cover cartridge and the DAP is dissolved in the water contained in the extinguisher.

The tests and results are summarized in the following table: Example Fire extinguisher capacity (I) Amounts used Fireplace Type Tested Obtaining extinction Minimum requirement (EN3) DAP (g) Foam concentrate (ml) 14 9 300 180 21A Yes 13A 15 9 400 180 21A Yes 13A 16 9 600 270 27A Yes 13A

The extinction of the various class A fireplaces is obtained, that is to say that no flame recovery occurs during the three minutes following the discharge of the extinguisher.

EXAMPLES 17 TO 20 (Comparisons)

• l'une sans inhibiteur de combustion (exemples 17 et 18)
• l'autre avec un rapport inhibiteur/émulseur supérieur à 6 (exemples 19 et 20)

ont été testées selon les mêmes procédures d'essais que dans les exemples 10 à 16.Two extinguishing compositions not in accordance with the present invention:

• one without combustion inhibitor (examples 17 and 18)
• the other with an inhibitor / foam concentrate ratio greater than 6 (examples 19 and 20)

were tested according to the same test procedures as in Examples 10 to 16.

These tests and their results are summarized in the following table: Example Fire extinguisher capacity (l) Amounts used Fireplace Type Tested Obtaining extinction Minimum requirement (EN3) DAP (g) Foam concentrate (ml) 17 9 0 90 233B Yes 183B 18 9 0 90 13A no 13A 19 9 720 90 21A Yes 13A 20 9 720 90 144B no 183B

In the absence of a combustion inhibitor (examples 17 and 18), the extinguisher does not meet the minimum requirement of the draft European standard EN 3 for class A fireplaces. The composition of examples 19 and 20 satisfies this requirement, but no longer meets the minimum requirement for Class B fireplaces; it is even ineffective on a 144B hearth.

Claims (10)

Portable water spray extinguisher containing an AFFF fire-fighting foam concentrate, characterized in that it additionally contains a combustion inhibitor, the mass ratio of the inhibitor to the foam concentrate being between 0.5 and 6. Fire extinguisher according to claim 1, in which the mass ratio is between 1 and 4. Fire extinguisher according to claim 1 or 2 which, per 100 parts of water, contains from 0.5 to 6 parts by weight of foam concentrate, preferably 1 to 3 parts, and from 1 to 20 parts by weight of combustion inhibitor , preferably 2 to 8 parts. Fire extinguisher according to one of claims 1 to 3, in which the inhibitor is chosen from ammonium phosphates, mixed ammonium and alkali metal ion phosphates, ammonium sulfates, and mixtures of such products . A fire extinguisher according to claim 4, wherein the inhibitor is mono-ammonium orthophosphate, di-ammonium orthophosphate, ammonium sulfate or a mixture of these compounds. Fire extinguisher according to one of claims 1 to 5, in which the foam concentrate is an aqueous or hydro-alcoholic solution comprising at least one fluorinated surfactant, at least one non-fluorinated surfactant, and at least one co- solvent, preferably a monoalkyl ether of mono- or di-ethylene (or propylene) glycol. Fire extinguisher according to claim 6, in which the foam concentrate contains from 5 to 25% by weight, preferably between 7 and 18%, of fluorinated surfactant (s), from 2 to 20% by weight, preferably between 4 and 18%, of non-fluorinated surfactant (s), and from 20 to 50% by weight, preferably between 30 and 45%, of co-solvent (s). Fire extinguisher according to claim 6 or 7, in which the fluorinated surfactant is chosen from the compounds of general formulas:

in which : - R _F represents a perfluoroalkyl radical, linear or branched, containing at least 6 carbon atoms, preferably from 6 to 16 carbon atoms; - m is an integer ranging from 0 to 6, preferably equal to 0 or 2; - X denotes a group CO or SO₂, preferably a group SO₂; - R represents a hydrogen atom or a methyl or ethyl radical; - n is an integer ranging from 1 to 5, preferably equal to 3; - R¹ and R², identical or different, each represent a methyl or ethyl radical; - p is an integer ranging from 1 to 5, preferably equal to 1, 2 or 3; and - Y ⁻ denotes a group SO₃⁻, OSO₃⁻ or COO⁻. Fire extinguisher according to one of Claims 6 to 8, in which the non-fluorinated surfactant is chosen from the compounds of general formulas

R _H -OSO₃M



R _H - (OC₂H₄) _q -OSO₃M



R _H (OC₂H₄) _q -OH



H (C₆H₁₀O₅) _r -OR _H

R _H -CONH-C₂H₄-NH-C₂H₄OC₂H₄COOM



R _H -NH-C₂H₄-COOH



R _H -N (C₂H₄COOM) ₂

$${\text{R}}_{\text{H}}\text{-N (CH₃) ₂ → O}$$

in which R _H represents an alkyl radical, linear or branched, containing from 8 to 18 carbon atoms, q is an integer ranging from 1 to 16, C₆H₁₀O₅ denotes a glucoside group, r is an integer ranging from 1 to 6, preferably equal to 1 or 2, and M denotes an alkali metal ion. Fire extinguisher according to one of Claims 6 to 9, in which the monoal kylether is monoethyl or monobutyl ether of ethylene glycol or monobutyl ether of diethylene glycol.