NL2023184B1 - Fire extinguishing solution for a B-class fire - Google Patents

Abstract

The present invention is in the field of a fire extinguish— ing solution for a B—class fire comprising fire extinguishing components, and a method of extinguishing a fire using said solution. The solution comprises as a remainder water. The components do not comprise E and are fully (100%) biodegrada— ble, i.e. non—detectable amounts.

Description

Fire extinguishing solution for a B-class fire

FIELD OF THE INVENTION The present invention is in the field of a fire extinguish- ing solution for a B-class fire comprising fully (100%) biode- gradable fire extinguishing components, and a method of extin- guishing a fire using said sclution. The solution comprises as a remainder water. The components do not comprise F.

BACKGROUND OF THE INVENTION The present invention is in the field of a fire extinguish- ing solution comprising a fully (100%) biodegradable fire ex- tinguishing agent.

Fire may be symbolized by a tetrahedron, which symbol char- acterizes itself by four (tetra) elements, namely oxygen, heat, fire source, and an uninhibited chain reaction. An opti- mized agent should preferably provide a chemical/physical ac- tion in all four of the tetrahedron domains.

A burning process can be chemically symbolized in the fol- lowing reaction scheme: CnHm + Oz through ignition — CO: +H20 wherein CniHu is a fire source. Ignition is considered to take place through heat. However, in reality the reaction is much more complex and typically comprising various intermediate and often incomplete steps. These steps may form radicals. If these could be captured or bounded the fire process may be in- terrupted and the fire may be easily extinguished.

A typical burning process may be divided into three phases, a growth phase, a burning phase, and an extinguishing phase, each with an accompanying temperature profile. In addition, there also is a spatial gradient. A heat gradient has a typi- 3C cal temperature profile from a peripheral temperature of about 20°C to a central temperature of some 1200° C or higher.

Traditional firefighting additives or foams are typically attacking only one of the four sides of the Tetrahedron {cool- ing down, covering a burning source, removing oxygen, and in- terrupting the chain reaction) and are therefore often not very effective.

Typical standard tests for extinguishing a fire are given in European norm EN 3-7:2004 +Al: 2007. For extinguishing flammable liquid fires (B Class) with foam products there is a 40 distinction made in the EN standards between miscible (EN

1568-3, March 2008) and immiscible liquids (EN 1568-4, March 2008). The EN 3-7:2004 +Al: 2007 standard specifies character- istics, performance requirements and test methods for portable fire extinguishers. Fire extinguishers with a Class B rating are effective against flammable liquid fires. These can be fires where cooking liquids, coil, gasoline, kerosene, or paint have become ignited. Two commonly used chemicals are effective in fighting these types of fires. Monoammonium phosphate ef- fectively smothers the fire, while sodium bicarbonate induces a chemical reaction which extinguishes the fire.

Various prior art fire extinguishers are available. Com- bined water and foam fire extinguishers extinguish the fire by taking away the heat element of the fire triangle. Foam agents also separate the oxygen element from the other elements. Car- bon Dioxide fire extinguishers extinguish fire by taking away the oxygen element of the fire triangle and also be removing the heat with a very cold discharge. Dry Chemical fire extin- guishers extinguish the fire primarily by interrupting the chemical reaction of the fire triangle. A widely used type of fire extinguisher is the multipurpose dry chemical that is ef- fective on Class A, B, and C fires. Ordinary dry chemical is for Class B & C fires only. It is considered important to use a correct extinguisher for a given purpose. Using an incorrect agent can allow the fire to re-ignite after apparently being extinguished successfully. Carbon dioxide can be used on Class B & C fires. Water extinguishers are for Class A fires only.

The above agents/extinguishers are however typically lim- ited in their applicability, do not extinguish a fire suffi- ciently, may be toxic to humans and the environment, are not degradable, may not be storage stable, etc.

Hence there still is a need for a relatively simple and ef- fective sclution for extinguishing a B-class fire, which over- comes one or more of the above-mentioned disadvantages without jeopardizing beneficial characteristics.

SUMMARY OF THE INVENTION The present invention relates in a first aspect to a foam forming fire extinguishing solution according to claim 1. It is aimed at extinguishing fires of or comparable to Class B fires. Said liquid comprises various components each providing a contribution to extinguishing a fire and in addition provid- ing a synergistic effect. The solution comprises as main com- ponents 1-10 wt.% polyvinyl alcohol (PVA) resin (CzHeC)n, 0-30 wt.% surfactant, 0-4 wt.% high molecular weight polymer, 0-3 wt.% biological polysaccharide, 0-7 wt.% isopropyl alcohol, 0O- wt.% tri ethanol amine {CegH1sNO3 CAS 1102-71-66), 0-6 wt.% foam enhancer, and the remainder water, with the proviso that no F is present, and that the solution is fully biodegradable, wherein all amounts are relative to a total weight of the com- 10 position. Surprisingly it has been found that the solution comprising PVA resin provides good foam coverage properties to an applied solution, and therewith extinguishes a B-class fire quickly and effectively. It is noted that it has been found very difficult to arrive at such a composition that is effec- tive in fire extinguishing and that is biodegradable, in par- ticular does not comprise F. It is noted that the compounds may be present as such, or as precursors or the like thereof. So, all of the components are fully biodegradable, non-toxic to human beings and to the environment. Each component may perform various functions. For instance, water evaporates to steam under consumption of large amounts of energy and thereby cools the fire. The produced foam spreads over the fire form- ing liquid and covers said liquid completely. Therewith the fire is extinguished permanently. It is noted that the fire source can not be influenced much or taken away typically.

The present solution, used as a spray, nebulized, or as a flow, is found to be very effective to extinguish a fire, as is supported by tests under standard conditions. In addition, the present agent fully decomposes into products not being harmful to the environment and human beings within 28 days un- der typical conditions. The present agent is stable for longer periods of time, typically more than 3-6 months and hence can be stored for at least said periods. Test under varying tem- peratures and conditions indicate a storage stability of at least 5 years. In addition, it consumes little space, and can therefore also be stored on location, such as a strategic sup- ply, without any problem.

The present solution forms foams with relatively small bub- bles, typically bubbles with an average size of <2mm, more typically <lmm, such as of 0.2-0.8 mm. The small bubbles are found to extinguish a B-calls fire (for which the norm EN 1568-3 or 4, respectively is applied) very well. The expansion ratio of the present solution is about 6 {vol./vol.}, which is typically qualified as a low expansion foam. For comparison, prior art F-comprising foams typically have an expansion ratio of 7-8. A 25% dewatering time of the present solution is about 18 minutes, and a 50% dewatering time is about 20 minutes. A small-scale fire is extinguished in about 51 seconds, and a burn back time of >10 minutes 1s achieved, such as >15 minutes. It is noted that increasing a burn back time typi- cally results in an increase in fire extinguishing time as well. It is therefore considered not that trivial to arrive at a solution which fulfills both, opposing, conditions. In a second aspect the present invention relates to a method of extinguishing a fire according to claim 12, such as a B-class fire, comprising providing a fire extinguishing so- lution according to the invention, spraying or dispensing the liquid on the fire, and extinguishing a fire with said liquid. Thereby the present invention provides a solution to one or more of the above-mentioned problems and drawbacks. Advantages of the present description are detailed throughout the description.

DETAILED DESCRIPTION OF TEE INVENTION The present invention relates in a first aspect to a fire extinguishing solution according to claim 1. In an exemplary embodiment of the present solution in the PVA resin ne[50-400] (i.e. n may be any number from 50 to and including 400), preferably ne[100-300], more preferably ne[150-250], even more preferably ne[175-225], such as ne[190- 210]. So relatively large poly vinyl alcohols function well. For instance, the PVA 385 of the present tests is very suita- ble. In an exemplary embodiment the present solution may com- prise 2-6 wt.% PVA resin, such as 3-5 wt.%. So small amounts of PVA resin are found sufficient to obtain the desired prop- erties. In an exemplary embodiment the present solution may com- prise 0.5-4 wt.% high molecular weight polymer, such as with a molecular weight of 5*104-107 Da, such as a polysaccharide, such as guar gum, xanthan gum, preferably 1-3 wt.%. The molec- ular weight may be determined by GPC/Maldi TOF/MS, using ISO 16014-5). 5 In an exemplary embodiment the present solution may com- prise 5-30 wt.% surfactant, preferably 10-25 wt.%, such as 15- 20 wt.%, such as alkyl polyglycol, alkyl glucoside, coco gly- coside, branched or unbranched Cs-Cis-sulphate, and lauryl sul- phate, such as SLS (CAS 151-21-3), and combinations thereof. In an exemplary embodiment the present solution may com- prise 3-10 wt.% tri ethanol amine (CgHisNO3 CAS 102-71-6), pref- erably 5-8 wt.%.

In an exemplary embodiment the present solution may com- prise 0.2-3 wt.% biological polysaccharide, such as alginate, and exopolysaccharide, such as formed by bacteria, preferably

0.5 -2 wt.%, such as 1-1.5 wt.%. Examples of exopolysaccha- rides can be found in WO 2015/190927 Al.

In an exemplary embodiment the present solution may com- prise 0.2-6 wt.% foam enhancer, preferably 1-5 wt.% foam en- hancer, such as 2-4 wt.% foam enhancer. The present foam en- hancer especially forms smaller bubbles.

In an exempiary embodiment of the present solution the foam enhancer is selected from quaternary ammonium compounds RiR2R3R4N*, wherein Ri, R2, R3, each independently are selected from Ci-C4 alkanes, preferably C1-C: alkanes, Rs independently is selected from Ci-C4 monocarboxylic acid groups, preferably Ci-C2 monocarboxylic acid groups, and combinations thereof, such as N,N,N-trimethyl glycine (betaine), N,N,N-dimethyl ethyl-glycine, N,N,N-methyl diethyi-glycine, and N,N,N-tri- ethyl glycine. The compounds are found to enhance foam proper- ties very well.

The one or more of the above examples and embodiments may be combined, falling within the scope of the invention.

EXAMPLES The invention is further detailed by the accompanying exam- ple, which is exemplary and explanatory of nature and are not limiting the scope of the invention. To the person skilled in the art it may be clear that many variants, being obvious or not, may be conceivable falling within the scope of protec- tion, defined by the present claims. Example Preparation of fire extinguishing liquid Various liquids are made as identified in table 1 and sub- sequently tested on various fire extinguishing properties ac- cording to EN 15683-3 small scale fire with an UNI 86 nozzle.

N N N N N N N N N N N N N N Component N7 7.1 7.2 7.3 7.4 74A 74B 75A 75B 76 7.7 78 7.9 7.10 7.11 N38 Glucopon 50 50 50 50 50 50 50 50 50 50 90 40 50 50 Simusol 50 Caflon C814 50 SLES 200 160 160 160 160 160 120 160 120 220 160 160 120 200 160 200

SLS Xanthan 7 7 7 7 7 7 7 7 7 7 7 7 7 7 14 7 Guar 3 3 3 3 3 3 3 3 3 3 3 3 3 3 6 3 Alginate (PGA ATL) 10 10 10 10 10 10 10 10 10 10 10 10 10 10 20 10 IPA 40 40 40 40 40 40 40 40 40 30 40 40 40 60 40 DEGB 80 Triethanolamine 80 80 80 8 80 80 80 80 80 80 80 80 80 40 40 Poval 3-85 40 40 40 40 40 40 40 40 40 40 40 Poval 3-86 5D 40 Poval 26-88 40 Poval 25-98 R 40 Betain CAPB 40 40 Water 610 610 610 610 610 610 610 610 610 610 610 610 570 620 610 690 TABLE 1 Test 1 For various compositions the dewatering time (25% and 50%) as well as extinguishing time, burn back time, and expansion ratio were measured. It is noted that variations in the compo- sitions may effect parameters in opposite ways (one becoming better, another becoming worse). 25% 50% 3F 9min {15min 7,34 51 sec 7,5 min N7.1 15 min 25 min 6,87 45 sec 14,5 min N7.2 >15 min |>15 min 5,5 51 sec 14 min N7.3 9 min 22 min 5,03 80 sec 6,5 min N7.4 15min | 25min 5,89 52 sec 10 min

Table 2: EN 15863-3 tests. Test 2 Foam forming liguids, and modified liquids have been tested further. 3F is a prior art product. 25% 50% 3F 7,5 min 12 min 6,31 3F Modified 3 min 7,5 min 5,72 3F met 85gr PVOH 7,5 min 17 min 55 3F met 65grPVOH | 7,5 min 15 min 6,2 N7.1 18 min 20 min 5,84 N7.4 15 min 23 min 4,89 N7.4A 7,5 min 13 min 4,53 N7.4B 5 min 11 min 4,12 N7.5A 7,5 min 11 min 4,7 N7.5B 6 min 11 min 4,8 N7.6 8 min 13,5 min 4,4 N8 13 min 23 min 4,33 Table 3: Further EN 15863-3 tests. Test 3 In four composition the effect of replacement of 40 gr SLS with betaine has been tested. 25% 50% N7.4A 7,5 min 13 min 4,53 N7.4B 5 min 11 min 4,12 2 EE 3 ij Table 4: Further EN 15863-3 tests. Test 4 In four composition the effect of replacement of 50 gr glu- copone with cocoglucose has been tested. 25% 50% N7 4A 7,5 min 13 min 4,53 N7.4B 5 min 11 min 4,12

AE N7.5B 6 min 11 min 4,8 Table 5: Further EN 15863-3 tests. Test 5 The effect of ethanolamine has been tested.

25% 50% N7.4 15 23 4,89 [52 sec 10 min. | 3H pe oe Table 6: Further EN 15863-3 tests. Test 6 The effect of SLS and less water and less IPA has been tested. 25% 50% N 7.4 15 23 4,89 | 52 sec 10 min. Table 7: Further EN 15863-3 tests. In conclusion composition N7.1 provides overall good results. Glucopone in combination with betaine result in worse foams. Dewatering is accelerated when using glucopone and betaine.

For the purpose of searching prior art the following sec- tion 1s added, representing a translation of the last section in English:

1. Fire extinguishing foam forming solution for a B-class fire, comprising 1-10 wt.% polyvinyl alcohol (PVA) resin (C2H40)1, 0-30 wt.% surfactant, 0-4 wt.% high molecular weight polymer, 0-3 wt.% biological polysaccharide, 0-7 wt.% isopropyl alcohol, 0-10 wt.% tri ethanol amine (CsHisNOQ3 CAS 102-71-6), 0-6 wt.% foam enhancer, and the remainder water, with the proviso that no F is present, and that the solu- tion is fully biodegradable, wherein all amounts are relative to a total weight of the composition.

2. Fire extinguishing solution according to embodiment 1, wherein in the PVA resin ne[50-400], preferably ne[100-300], more preferably ne[150-250], even more preferably ne[175-225}, such as ne[190-210].

3. Fire extinguishing solution according to any of the preced- ing embodiments, comprising 2-6 wt.% PVA resin, such as 3-5 wt.%.

4. Fire extinguishing solution according to any of the preced- ing embodiments, comprising 0.5-4 wt.% high molecular weight polymer, such as with a molecular weight of 5*104-107 Da, such as a polysaccharide, such as guar gum, xanthan gum, preferably 1-3 wt.%.

5. Fire extinguishing solution according to any of the preced- ing embodiments, comprising 5-25 wt.% surfactant, preferably 10-25 wt.%, such as 15-20 wt.%, such as alkyl polyglycol, al- kyl glucoside, coco glycoside, branched or unbranched Cg-Cis- sulphate, and lauryl sulphate, such as SLS (CAS 151-21-3), and combinations thereof.

6. Fire extinguishing sclution according to any of the preced- ing embodiments, comprising 3-10 wt.$% tri ethanol amine (CsHisNO3 CAS 1022-71-86), preferably 5-8 wt.%.

7. Fire extinguishing solution according to any of the preced- ing embodiments, comprising 0.2-3 wt.% biological polysaccha- ride, such as alginate, and exopolysaccharide, preferably 0.5 -Z2 wt.%, such as 1-1.5 wt.%.

8. Fire extinguishing solution according to any of the preced- ing embodiments, comprising 2-7 wt.% isopropyl alcohol, pref- erably 3-5 wt.%, such as 4 wt.%.

9. Fire extinguishing solution according to any of the preced- ing embodiments, comprising 0.2-6 wt.% foam enhancer, prefera- bly 1-5 wt.% foam enhancer, such as 2-4 wt.$% foam enhancer.

10. Fire extinguishing solution according to any of the pre- ceding embodiments, wherein the foam enhancer is selected from quaternary ammonium compounds RiR:R3R:N*, wherein Ri, Rs, Raz, each independently are selected from Ci-Cs alkanes, preferably Ci1~Cz alkanes, R4 independently is selected from C1-C4 monocar- boxylic acid groups, preferably Ci1-Cz monocarboxylic acid groups, and combinations thereof, such as N,N,N-trimethyl gly- cine, N,N,N-dimethyl ethyl-glycine, N,N,N-methyl diethyl-gly- cine, and N,N,N-triethyl glycine.

11. Method of extinguishing a fire, such as a B-class fire, comprising providing a fire extinguishing solution according to any of embodiments 1-10, spraying or dispensing the liquid on the fire, and extinguishing a fire with said liquid.

Claims (11)

CONCLUSIONS Extinguishing foam-forming solution for a B-class fire, comprising 1-10 wt.% Polyvinyl alcohol (PVA) resin (C: H4O), 0-30 wt.% Surfactant, 0-4 wt.% High molecular polymer, 0- 3 wt.% Biclogical polysaccharide, 0-7 wt.% Isopropyl alcohol, 0-10 wt.% Triethanolamine (C5 H18 NO3 CAS 1102-71-06), 0-6 wt.% Foam builder, and the balance water, provided that no F is present and that the solution is completely biodegradable, all amounts being relative to the total weight of the composition. A fire extinguishing solution according to claim 1, wherein in the PVA resin ne [50-400], preferably ne [100-300], more preferably ne [150-250], even more preferably ne [175-225], such as ne [1980 -210]. A fire-extinguishing solution according to any preceding claim, comprising 2-6% by weight PVA resin, such as 3-5% by weight. Fire extinguishing solution according to any one of the preceding claims, comprising 0.5-4% by weight high molecular weight polymer, such as with a molecular weight of 5 * 104-107 Da, such as a polysaccharide, such as guar gum, xanthan gum, preferably 1 -3% by weight. Fire extinguishing solution according to any one of the preceding claims, comprising 5-25% by weight surfactant, preferably 10-25% by weight, such as 15-20% by weight, such as alkyl polyglycol, alkyl glucodide, coconut glycoside, branched or straight chain Ce-C18 sulfate, and lauryl sulfate, such as SLS (CAS 151-21-3), and combinations thereof. Fire extinguishing solution according to any one of the preceding claims, comprising 3-10 wt.% Triethanclamine (CsH: sNO3 CAS 102-71-6), preferably 5-8 wt.%. Fire-extinguishing solution according to any one of the preceding claims, comprising 0.2-3% by weight of biological polysaccharide, such as alginate, and exopolysaccharide, preferably 0.5-2% by weight, such as 1-1.5% by weight. %. Fire-extinguishing solution according to any of the preceding claims, comprising 2-7% by weight of isopropyl alcohol, preferably 3-5% by weight, such as 4% by weight. Fire extinguishing solution according to any one of the preceding claims, comprising 0.2-6% by weight foam booster, preferably 1-5% by weight foam booster, such as 2-4% by weight foam booster. A fire-fighting solution according to any one of the preceding claims, wherein the foam is 2-4% by weight selected from quaternary ammonium compounds R 1 R 2 R 3 R 4 N *, wherein R 1, R 2, R 3 are each independently selected from C 1 -C 8 alkanes, preferably C 1 -C2-alkanes, R5 is independently selected from C: 1 -C4 monocarboxylic acid groups, preferably C 1 -C: monocarboxylic acid groups, and combinations thereof, such as N, N, N-trimethylglycine, N, N, N-dimethylethyl glycine, N, N, N-methyl-diethyl-glycine, and N, N, N-triethyl glycine. Method for extinguishing a fire, such as a B class fire, comprising providing a fire extinguishing solution according to any one of claims 1 to 10, spraying or dosing the liquid on the fire, and extinguishing a fire fire with this liquid.