Flameless condensed aerosol fire extinguishing agent and preparation method therefor

Abstract

The present invention provides a flameless condensed aerosol fire extinguishing agent and a preparation method therefor. The flameless condensed aerosol fire extinguishing agent comprises the following components in percentage by mass: 50-70% of an oxidizing agent, 5-30% of a reducing agent, 5-20% of an adhesive, and 0.5-5% of an additive, wherein the additive comprises one or more of phenolic resin, potassium oxalate, potassium hydrogen phthalate, and potassium tartrate. In the present invention, the adhesive added has the function of bonding components and also has the effects of cooling and stabilizing combustion. However, after the adhesive is added, aggregation is prone to occurring in the combustion process of the condensed aerosol fire extinguishing agent. By using one or more of phenolic resin, potassium oxalate, potassium hydrogen phthalate, and potassium tartrate as the additive and adding a small amount of the additive to the fire extinguishing agent, components of the adhesive are not prone to quick aggregation, so that the internal temperature distribution is more uniform during combustion of a chemical agent, thereby achieving a flameless combustion effect and also ensuring uniform release of a fire extinguishing medium.

Description

Flameless hot aerosol fire extinguishing agent and preparation method thereof Technical Field

[0001] The invention belongs to the technical field of fire fighting and extinguishing, and particularly relates to a flameless thermal aerosol fire extinguishing agent and a preparation method thereof. Background Art

[0002] Thermal aerosol fire extinguishing technology has been maturely used in the firefighting field and has proven its value in a variety of firefighting products. However, existing thermal aerosol fire extinguishing devices, primarily composed of aerosol extinguishing agents and coolants, present significant challenges in extinguishing flames and cooling during use. Some products still exhibit flames, hindering their use in flame-sensitive environments.

[0003] Regarding the problem of flames generated during the use of hot aerosol fire extinguishing devices, the existing technology mainly uses the method of adding external coolants to reduce the intensity of the flames, but it cannot fundamentally solve the problem of flame ejection. In addition, the volume of the existing device is also larger due to the large amount of coolant added, which also puts higher requirements on its installation, maintenance and use.

[0004] Summary of the Invention

[0005] The present invention provides a flameless hot aerosol fire extinguishing agent and a preparation method thereof. The fire extinguishing agent can achieve flameless combustion of the agent, completely avoid the use of coolant, help to reduce the structure and volume of the fire extinguishing device, reduce the cost of the device, and also promote the application of the device in flame-sensitive scenarios.

[0006] The technical solution of the present invention is a flameless thermal aerosol fire extinguishing agent, which includes the following components in percentage by mass: 50-70% oxidant, 5-30% reducing agent, 5-20% adhesive and 0.5-5% additive; wherein the additive is one or more of phenolic resin, potassium oxalate, potassium hydrogen phthalate and potassium tartrate.

[0007] Furthermore, the oxidant is one or more of potassium nitrate, strontium nitrate, sodium nitrate or magnesium nitrate.

[0008] Furthermore, the reducing agent is one or more of starch, wood powder, charcoal, cellulose, urea, nitroguanidine, melamine, dicyandiamide and 5-aminotetrazole.

[0009] Furthermore, the binder is one or more of kaolin, clay, bentonite and diatomaceous earth.

[0010] More preferably, the additive is phenolic resin, and the added amount is 0.5-2%.

[0011] The present invention also relates to a method for preparing the flameless thermal aerosol fire extinguishing agent, comprising the following steps:

[0012] S1. Sieve the oxidant, reducing agent, binder and additives respectively and mix them in proportion;

[0013] S2, adding ethanol solution to the above mixture and mixing;

[0014] S3. Granulate the material obtained in S2, and obtain a flameless hot aerosol fire extinguishing agent after drying.

[0015] Furthermore, the sieve in S1 is a 100-120 mesh sieve.

[0016] Furthermore, the amount of ethanol solution added to S2 is 15-30% of the total mass of the mixture; and the mass concentration of the ethanol solution is 40-60%.

[0017] Furthermore, sieve granulation is adopted during granulation in S3, and the sieve aperture is 14-20 mesh.

[0018] Furthermore, the drying temperature is 40-60°C.

[0019] The present invention has the following beneficial effects:

[0020] The adhesive added in the present invention plays the role of bonding each component and also has the effect of cooling and stable combustion; but after the adhesive is added, in the combustion process of the hot aerosol fire extinguishing agent, it is easy to gather, which can cause the flameless effect to be achieved due to the excessively high local temperature when the agent burns, and also form a hard layer that hinders the ejection of the fire extinguishing medium, affecting the performance of the hot aerosol fire extinguishing agent fire extinguishing effect. The inventor has found that using phenolic resin, potassium oxalate, potassium hydrogen phthalate and / or potassium tartrate as additives, a small amount of addition to the fire extinguishing agent can help accelerate the combustion reaction, making the adhesive component difficult for rapid aggregation, so that the internal temperature distribution is more uniform when the agent burns, achieving the effect of burning flameless, while also ensuring the uniform release of the fire extinguishing medium. Especially phenolic resin, although it can be used as a refractory material, when it exists simultaneously with a large amount of oxidants, it can burn, and this combustion is an exothermic reaction, which is conducive to raising the reaction temperature of the agent, thereby accelerating the burning rate of the agent. At the same time, its combustion can produce gases such as carbon dioxide, and gas can form a gas channel to prevent the adhesive component from gathering during rapid escape. The addition of appropriate amounts of potassium oxalate, potassium hydrogen phthalate and / or potassium tartrate can play a similar role to that of phenolic resin.

[0021] Currently reported thermal aerosol fire extinguishing agents primarily use flammable polymer compounds containing carbon, hydrogen, and oxygen, such as resins, shellac, and cellulose derivatives, as binders. These compounds readily produce combustible gases such as carbon monoxide and hydrogen when burned. When large amounts of these gases burn, they form a flame layer, manifesting as a burning flame. The present invention uses a non-combustible material as a binder, which not only reduces the amount of binder required to generate combustible gases but also hinders the escape of the combustible gases produced by combustion, preventing them from emitting flames and achieving a flameless combustion effect. Using a small amount of phenolic resin in the presence of a non-combustible binder ensures the flameless combustion effect of the agent and the uniform release of the fire extinguishing medium. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] FIG1 is a photograph of the combustion process of the hot aerosol fire extinguishing agent in Example 1.

[0023] FIG2 is a photograph of the hot aerosol fire extinguishing agent after combustion in Comparative Example 2. DETAILED DESCRIPTION

[0024] The embodiments of the present invention will be described in detail below with reference to examples. However, those skilled in the art will understand that the following examples are only used to illustrate the present invention and should not be regarded as limiting the scope of the present invention.

[0025] Example 1

[0026] A flameless hot aerosol fire extinguishing agent is prepared by preliminarily mixing, by weight percentage, 60% potassium nitrate, 29% starch, 10% kaolin and 1% phenolic resin through a 100-mesh sieve, further stirring and mixing the mixture, adding a 15% ethanol solution (40% by weight of ethanol), stirring thoroughly to mix the mixture evenly, and finally passing the mixture through a 20-mesh sieve to form granules, and drying at 50°C to obtain the hot aerosol fire extinguishing agent.

[0027] Example 2

[0028] A flameless hot aerosol fire extinguishing agent is prepared by preliminarily mixing, by mass percentage, 65% strontium nitrate, 18% melamine, 15% clay and 2% potassium hydrogen phthalate through a 100-mesh sieve, further stirring the mixture, adding a 20% ethanol solution (40% by mass of ethanol) thereto, stirring thoroughly to make the mixture uniform, and finally passing the mixture through a 20-mesh sieve to form granules, and drying at 50°C to obtain the hot aerosol fire extinguishing agent.

[0029] Example 3

[0030] A flameless hot aerosol fire extinguishing agent is prepared by preliminarily mixing, by weight percentage, 55% magnesium nitrate, 25% 5-aminotetrazole, 17% bentonite and 3% potassium tartrate through a 100-mesh sieve, further stirring and mixing the mixture, adding a 20% ethanol solution (50% by weight of ethanol), stirring thoroughly to make the mixture uniform, and finally passing the mixture through a 20-mesh sieve to form granules, and drying at 50°C to obtain the hot aerosol fire extinguishing agent.

[0031] Example 4

[0032] The invention discloses a flameless hot aerosol fire extinguishing agent. The invention discloses a flameless hot aerosol fire extinguishing agent. The flameless aerosol fire extinguishing agent comprises the following steps: preliminarily mixing 50% sodium nitrate, 30% dicyandiamide, 15% clay and 5% potassium oxalate through a 100-mesh sieve, further stirring the mixture, adding a 30% ethanol solution (50% by mass of ethanol) thereto, stirring the mixture thoroughly to make the mixture uniform, and finally passing the mixture through a 20-mesh sieve to form granules. The mixture is then dried at 50°C to obtain the hot aerosol fire extinguishing agent.

[0033] Example 5

[0034] A flameless hot aerosol fire extinguishing agent is prepared by preliminarily mixing 70% strontium nitrate, 5% charcoal, 20% kaolin and 5% phenolic resin by weight through a 100-mesh sieve, further stirring the mixture, adding a 20% ethanol solution (ethanol mass fraction of 60%), stirring thoroughly to make the mixture uniform, and finally passing the mixture through a 20-mesh sieve to form granules, and drying at 50°C to obtain the hot aerosol fire extinguishing agent.

[0035] Example 6

[0036] The invention discloses a flameless hot aerosol fire extinguishing agent. The invention discloses a flameless hot aerosol fire extinguishing agent. The flameless aerosol fire extinguishing agent comprises the following steps: preliminarily mixing 50% sodium nitrate, 30% dicyandiamide, 15% bentonite and 5% phenolic resin by weight through a 100-mesh sieve; further stirring the mixture, adding a 20% ethanol solution (ethanol mass fraction of 60%) thereto, stirring the mixture thoroughly to make the mixture uniform; finally, passing the mixture through a 20-mesh sieve to form granules, and drying the granules at 50°C to obtain the hot aerosol fire extinguishing agent.

[0037] Example 7

[0038] 7-1: Based on Example 1, the only difference is that the starch is 25% and the phenolic resin is 5%.

[0039] 7-2: Based on Example 1, the only difference is that the starch is 27% and the phenolic resin is 3%.

[0040] 7-3: Based on Example 1, the only difference is that the phenolic resin is replaced by potassium hydrogen phthalate.

[0041] Example 8

[0042] The invention discloses a preparation method for a flameless hot aerosol fire extinguishing agent. The method comprises the following steps: preliminarily mixing 30% sodium nitrate, 30% potassium nitrate, 10% charcoal, 15% urea, 5% clay, 8% kaolin and 2% phenolic resin by weight through a 100-mesh sieve; further stirring the mixture, adding a 20% ethanol solution (ethanol mass fraction: 60%) thereto, stirring the mixture thoroughly to make the mixture uniform; finally, passing the mixture through a 20-mesh sieve to form granules, and drying the granules at 50°C to obtain the hot aerosol fire extinguishing agent.

[0043] Comparative Example 1

[0044] Based on Example 1, the only difference is that the raw materials are 60% potassium nitrate, 29% starch, 10% epoxy resin, and 1% phenolic resin.

[0045] Comparative Example 2

[0046] Based on Example 1, the only difference is that the raw materials are 60% potassium nitrate, 30% starch, and 10% kaolin, and no phenolic resin is added.

[0047] Comparative Example 3

[0048] Based on Example 1, the only difference is that the raw materials are 60% potassium nitrate, 29.9% starch, 10% kaolin, and 0.1% phenolic resin.

[0049] Comparative Example 4

[0050] Based on Example 1, the only difference is that the raw materials are 58% potassium nitrate, 28% starch, 8% kaolin, and 6% phenolic resin.

[0051] The hot aerosol fire extinguishing agents obtained in the above examples and comparative examples were pressed into cylindrical charges with a diameter of 32 mm at a pressure of 5 MPa and subjected to combustion tests. The test results are shown in Table 1 below.

[0052] Table 1

[0053] The above table shows the combustion conditions of the hot aerosol fire extinguishing agents prepared in various embodiments. Compared with existing hot aerosol fire extinguishing agents that exhibit obvious visible combustion flames during combustion and even combustion temperatures exceeding 800°C, the hot aerosol fire extinguishing agents prepared by the present invention exhibit combustion temperatures below 400°C and no obvious flame phenomenon during combustion.

[0054] Figure 1 shows a photograph of the hot aerosol fire extinguishing agent during combustion in Example 1, while Figure 2 shows a photograph of the hot aerosol fire extinguishing agent after combustion in Comparative Example 2. Compared to combustion residues without the additive, the additive significantly reduces residue aggregation in the present invention, facilitating the uniform release of the extinguishing medium and significantly improving fire extinguishing capability.

[0055] The above embodiments are merely illustrative of the technical concepts and features of the present invention. The contents described are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Within the technical scope disclosed by the present invention, equivalent changes or improvements based on the technical solutions and inventive concepts of the present invention are all encompassed within the scope of protection of the present invention.

Claims

1. A flameless hot aerosol fire extinguishing agent, It is characterized in that The invention comprises the following components in percentage by mass: 50-70% of an oxidant, 5-30% of a reducing agent, 5-20% of a binder and 0.5-5% of an additive; wherein the additive is one or more of phenolic resin, potassium oxalate, potassium hydrogen phthalate and potassium tartrate.

2. The flameless thermal aerosol fire extinguishing agent according to claim 1, Features: The oxidant is one or more of potassium nitrate, strontium nitrate, sodium nitrate or magnesium nitrate.

3. The flameless thermal aerosol fire extinguishing agent according to claim 1, Features: The reducing agent is one or more of starch, wood powder, charcoal, cellulose, urea, nitroguanidine, melamine, dicyandiamide and 5-aminotetrazole.

4. The flameless thermal aerosol fire extinguishing agent according to claim 1, Features: The binder is one or more of kaolin, clay and bentonite.

5. The flameless thermal aerosol fire extinguishing agent according to claim 1, Features: The additive is phenolic resin, and the added amount is 0.5-2%.

6. A method for preparing the flameless thermal aerosol fire extinguishing agent according to any one of claims 1 to 5, It is characterized in that The following steps are involved: S1. Sieve the oxidant, the reducing agent, the adhesive and the additive respectively and mix them according to the proportion; S2, adding ethanol solution to the above mixture and mixing; S3, granulating the material obtained in S2, and obtaining a flameless hot aerosol fire extinguishing agent after drying.

7. The preparation method according to claim 6, Features: The screen in S1 is a 100-120 mesh screen.

8. The preparation method according to claim 6, Features: The amount of ethanol solution added to S2 is 15-30% of the total mass of the mixture; the mass concentration of the ethanol solution is 40-60%.

9. The preparation method according to claim 6, Features: In S3, sieve granulation is adopted, and the aperture of the sieve is 14-20 mesh.

10. The preparation method according to any one of claims 6 to 9, Features: The drying temperature is 40-60℃.

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