FIREFIGHTING COMPOSITIONS

Abstract

The disclosure relates to firefighting measures, and in particular, to firefighting compositions for preventing, retarding and extinguishing fire in a combustion zone that comprises a combination of at least one cooling component, at least one fire-isolation component comprising, at least one oxidizer diluting component, and at least one flame retarding component.

Claims

1. A fire firefighting composition for preventing, retarding, and/or extinguishing a fire in a combustion zone, the composition comprises at least one cooling component, at least one fire-isolation component comprising at least one sulfate salt and at least one alum, at least one oxidizer diluting component, and at least one flame retarding component, the weight ratio between said at least one sulfate salt and at least one alum is in the range of between about 2:1 to about 8:1.

2. The composition of claim 1, wherein said sulfate salt is one or more of an alkali sulfate salt and an alkali earth sulfate salt.

3. The composition of claim 1, wherein the alum is selected from at least one of alum potassium sulfate (KAl(SO.sub.4).sub.2.Math.12H.sub.2O), alum sodium sulfate (NaAl(SO.sub.4).sub.2.Math.12H.sub.2O), and alum ammonium sulfate (NH.sub.4Al(SO.sub.4).sub.2.Math.12H.sub.2O), and any mixture thereof.

4-6. (canceled)

7. The composition of claim 1, wherein the fire-isolation component further comprises one or more of alkali alkyl sulfate salts, silicon dioxide, ammonium halides, odium alkyl sulfate, and mixtures thereof.

8. The composition of claim 1, wherein the cooling component is selected from sodium bicarbonate (NaHCO.sub.3), ammonium sulfate ((NH.sub.4).sub.2SO.sub.4), urea (CO(NH.sub.2).sub.2), sulfamic acid (NH.sub.2SO.sub.3H), ammonium chloride (NH.sub.4Cl), and mixtures thereof.

9. The composition of claim 1, wherein the oxidizer diluting component is from one or more compounds that form carbon dioxide as one or their thermal decomposition products.

10. The composition of claim 9, wherein the oxidizer diluting component is selected from carbonate metal salts, bicarbonate metal salts, urea (or carbamate), sulphates, and mixtures thereof.

11. The composition of claim 10, wherein the oxidizer diluting component is selected from sodium bicarbonate (NaHCO.sub.3), potassium bicarbonate (KHCO.sub.3), sodium carbonate (Na.sub.2CO.sub.3), potassium carbonate (K.sub.2CO.sub.3), urea ((NH.sub.2).sub.2CO), and mixture thereof.

12. The composition of claim 1, wherein the flame retardant is a bicarbonate salt.

13. (canceled)

14. The composition of claim 1, wherein the composition is formulated for extinguishing fire at a burning temperature range of between about 60° C. to about 1000° C.

15. The composition of claim 1, wherein the composition comprises one or more pigments.

16. The composition of claim 1, comprising sulfamic acid, ammonium sulfate, urea, ammonium chloride, sodium bicarbonate, sodium sulfate, alum potassium sulfate, and sodium alkyl sulfate, and optionally comprising silicon dioxide.

17. The composition of claim 1, comprising sulfamic acid in amount of between about 0.4 wt % and about 30 wt %, ammonium sulfate in an amount of between about 0.5 wt % and about 50 wt %, urea in an amount of between about 0.3 wt % and about 20 wt %, ammonium chloride in an amount of between about 0.05 wt % and about 10 wt %, sodium bicarbonate in an amount of between about 0.05 wt % and about 10 wt %, sodium sulfate in an amount of between about 0.05 wt % and about 10 wt %, alum potassium sulfate in an amount of between about 0.01 wt % and about 2.5 wt %, and sodium alkyl sulfate in an amount of between about 0.01 wt % and 5 wt %, and optionally comprising silicon dioxide in an amount of between about 0.01 wt % and about 5 wt %.

18. The composition claim 1, being in the form of a powder.

19. The composition of claim 18, wherein the powder comprises no more than about 5 wt % water.

20. The composition of claim 18 or 19, wherein the powder has an average particle size in the range of between about 50 nm and about 150 μm.

21. The composition of claim 20, wherein the powder particles have a mono-modal size distribution.

22. (canceled)

23. The composition of claim 1, further comprising a non-flammable liquid and the composition being in a liquid form.

24. The composition of claim 23, wherein the non-flammable liquid is water.

25. A firefighting composition for preventing, retarding, and/or extinguishing a fire in a combustion zone, the composition being in dry powder form and comprises at least one cooling component, at least one fire-isolation component comprising at least one sulfate salt and at least one alum, at least one oxidizer diluting component, and at least one flame retarding component, the weight ratio between said at least one sulfate salt and at least one alum is in the range of between about 2:1 to about 8:1.

26. A firefighting composition for preventing, retarding, and/or extinguishing a fire in a combustion zone, the composition being in liquid form and comprising at least one cooling material, at least one fire-isolation material comprising at least one sulfate salt and at least one alum, at least one oxidizer diluting material, at least one flame retarding material, and at least one non-flammable liquid, the weight ratio between said at least one sulfate salt and at least one alum is in the range of between about 2:1 to about 8:1.

27. The firefighting composition in powder form of claim 25, comprising sulfamic acid, ammonium sulfate, urea, ammonium chloride, sodium bicarbonate, sodium sulfate, alum potassium sulfate, and sodium alkyl sulfate, and optionally comprising silicon dioxide.

28. The composition of claim 27, comprising sulfamic acid in amount of between about 0.4 wt % and about 30 wt %, ammonium sulfate in an amount of between about 0.5 wt % and about 50 wt %, urea in an amount of between about 0.3 wt % and about 20 wt %, ammonium chloride in an amount of between about 0.05 wt % and about 10 wt %, sodium bicarbonate in an amount of between about 0.05 wt % and about 10 wt %, sodium sulfate in an amount of between about 0.05 wt % and about 10 wt %, alum potassium sulfate in an amount of between about 0.01 wt % and about 2.5 wt %, and sodium alkyl sulfate in an amount of between about 0.01 wt % and 5 wt %, optionally comprising silicon dioxide in an amount of between about 0.01 wt % and about 5 wt %.

29-30. (canceled)

31. The composition of claim 26, the composition comprising a non-flammable liquid, sulfamic acid, ammonium sulfate, urea, ammonium chloride, sodium bicarbonate, sodium sulfate, alum potassium sulfate, and sodium alkyl sulfate, and optionally comprising silicon dioxide.

32. The composition of claim 31, comprising said non-flammable liquid in an amount of between about 50 wt % and 95 wt %, and a mixture of components in an amount of between about 5 wt % and 50 wt %, said mixture of components comprising (in weight % out of the total amount of the mixture of materials): sulfamic acid in amount of between about 0.4 wt % and about 30 wt %, ammonium sulfate in an amount of between about 0.5 wt % and about 50 wt %, urea in an amount of between about 0.3 wt % and about 20 wt %, ammonium chloride in an amount of between about 0.05 wt % and about 10 wt %, sodium bicarbonate in an amount of between about 0.05 wt % and about 10 wt %, sodium sulfate in an amount of between about 0.05 wt % and about 10 wt %, alum potassium sulfate in an amount of between about 0.01 wt % and about 2.5 wt %, and sodium alkyl sulfate in an amount of between about 0.01 wt % and 5 wt %, and optionally comprising silicon dioxide in an amount of between about 0.01 wt % and about 5 wt %.

33-49. (canceled)

Description

DETAILED DESCRIPTION OF EMBODIMENTS

[0099] As noted, the fire extinguishing composition includes a plurality of fire extinguishing components. Each extinguishing component operates in a corresponding temperature range, and provides at least one fire extinguishing effect, such as cooling, dilution, isolation and retardation, thus providing a fire extinguishing functionality over a broad range of temperatures and fire conditions. Further, at least some components of the composition were found to provide a synergistic fire extinguishing effect when combined, resulting in significantly improved extinguishing performance enabling utilization of significantly less amounts of composition to obtain complete extinguishing of fire, as well as reducing the time required to obtain complete fire extinguishing.

[0100] Table 1 shows the activity temperature range and the extinguishing effect(s) of an exemplary firefighting composition according to the present disclosure.

TABLE-US-00001 TABLE 1 Exemplary firefighting composition Activity temperature Extinguishing Component range (° C.) effect(s) Sodium bicarbonate  60° C. to 200° C. Cooling, dilution NaHCO.sub.3 and flame retarding Ammonium sulfate 170° C. to 500° C. Cooling (NH.sub.4).sub.2SO.sub.4 Urea CO(NH.sub.2).sub.2 130° C. to 275° C. Cooling and dilution Sulfamic acid NH.sub.2SO.sub.3H 260° C. to 400° C. Cooling Ammonium chloride 520° C. to 530° C. Cooling and NH.sub.4Cl isolation Sodium sulfate Na.sub.2SO.sub.4 880° C. to 890° C. Foaming agent, isolation Alum potassium >900° C. Isolation KAl(SO.sub.4).sub.2•12H.sub.2O Silicon dioxide SiO.sub.2  800° C. to 1000° C. Isolation Sodium alkyl sulfate 210° C. to 220° C. Isolation CH.sub.3(CH.sub.2).sub.11OSO.sub.2Na

[0101] As can be seen from Table 1, each component in the firefighting composition has a corresponding activity temperature range and one or more fire extinguishing effect(s). Thus, the fire-fighting composition operates in the entire temperature range of 60° C. to 1000° C. This temperature range is rather broad and is suitable for extinguishing fires of various classes.

EXAMPLE 1: PREPARATION OF A FIREFIGHTING COMPOSITION IN POWDER FORM

Preparation of Dry Powders

[0102] Ammonium sulfate, sulfamic acid, urea, ammonium chloride, sodium bicarbonate, sodium sulfate, alum potassium, and sodium alkyl sulfate are provided, typically in the form of granules having a size of between about 0.5 mm and about 2 mm.

[0103] The granules were dried for about 0.5-1 hours at 40-60° C., until reaching a moisture content of below 5 wt %.

[0104] The dried granules of each material were separately ground in a ball mill to obtain powders having an average particle size of 50 nm to 150 μm with a mono-modal size distribution (a size distribution of about ±20% from the average particle size).

[0105] The powders were then blended according to the following composition, thus obtaining the firefighting composition: [0106] ammonium sulfate at a concentration from 0.5 wt % to 50 wt %, [0107] sulfamic acid at a concentration from 0.4 wt % to 30 wt %, [0108] urea at a concentration from 0.3 wt % to 20 wt %, [0109] ammonium chloride at a concentration from 0.05 wt % to 10 wt %, [0110] sodium bicarbonate at a concentration from 0.05 wt % to 10 wt %, [0111] sodium sulfate at a concentration from 0.05 wt % to 10 wt %, [0112] alum potassium at a concentration from 0.01 wt % to 2.5 wt %, [0113] silicon dioxide at a concentration from 0.01 wt % to 5 wt %, and [0114] and sodium alkyl sulfate at a concentration from 0.01 wt % to 5 wt %.

EXAMPLE 2: PREPARATION OF A FIREFIGHTING LIQUID COMPOSITION

Preparation of Ingredients

[0115] Ammonium sulfate, sulfamic acid, urea, ammonium chloride, sodium bicarbonate, sodium sulfate, alum potassium, and sodium alkyl sulfate are provided, typically in the form of granules having a size of between about 0.5 mm and about 2 mm.

[0116] The granules were dried for about 0.5-1 hours at 40-60° C., until reaching a moisture content of below 5 wt %.

[0117] The dried granules of each material can optionally be ground in a ball mill to obtain powders having an average particle size of 50 nm to 150 μm with a mono-modal size distribution (a size distribution of about ±20% from the average particle size).

Preparation of Liquid Composition

[0118] Water was fed into a suitable reactor. The other components were added according to an exemplary composition set out in Table 2.

TABLE-US-00002 TABLE 2 Exemplary firefighting compositions (in wt %) Component Exemplary composition Sodium bicarbonate 5-10 wt % Ammonium sulfate 20-50 wt % Urea 7.5-20 wt % Sulfamic acid 7-30 wt % Ammonium chloride 5-10 wt % Sodium sulfate 2-10 wt % Alum potassium 0.5-2.5 wt % Sodium alkyl sulfate 1-5 wt %

[0119] Sulfamic acid was added into the reactor and mixed for dissolving, e.g. for 5-7 minutes. Then, ammonium sulfate and urea were added into the reactor and mixed for about 8-12 minutes until dissolving. Ammonium chloride was added into the reactor and let to dissolve. Sodium bicarbonate was gradually added for obtaining a pH in the range of 5.0-5.5, and mixed to dissolving. Sodium sulfate and alum potassium were then added, mixed and dissolved until reaching a pH in the range of 8 to 9, followed by addition of sodium alkyl sulfate.

EXAMPLE 3: COMPARATIVE FIRE EXTINGUISHING TESTS

[0120] Liquid compositions according to the formulation described in Example 2 were prepared. For comparative purposes, liquid compositions were prepared without alum potassium and/or without sodium sulfate.

[0121] Extinguishing of a standard A-0.5 hearth was tested under standard weather conditions: air temperature 32° C., western wind 6-8 m/s, air humidity 25%, daylight hours 12 AM. The test results are detailed in Table 3.

TABLE-US-00003 TABLE 3 Comparative fire extinguishing test results Time to Volume complete fire of solution Test Composition extinguishing used P1 Example 2, without alum potassium 31 seconds 2.1 liters P2 Example 2, without sodium sulfate 26 seconds 1.9 liters P3 Example 2 10 seconds 0.5 liters P4 Example 2, without alum potassium 44 seconds 3.6 liters and sodium sulfate P5 Water 70 seconds 9.0 liters

[0122] As can clearly be observed, compositions that included only one of alum potassium and sodium sulfate have shown similar fire extinguishing results in both time and volume required to obtain extinguishing of the fire (P1,P2).

[0123] However, when combined (P3), surprising reduction of extinguishing time was obtained — extinguishing utilization composition P3 was obtained already at 30% of the time required for examples P1 and P2. Further, the volume of solution required in order to obtain complete extinguishing with composition P3 was only 25% of the volume required when using formulations P1 and P2. Therefore, as can clearly be observed, the combination of alum potassium and sodium sulfate proved to have an unexpected synergistic effect on the fire extinguishing performance of the composition.