Fire extinguishing bomb for fire-fighting unmanned aerial vehicle and preparation method of fire extinguishing bomb

Abstract

The invention relates to the technical field of fire extinguishing, in particular to a fire extinguishing bomb for a fire-fighting unmanned aerial vehicle and a preparation method thereof.The fire extinguishing bomb is composed of a solid particle aerosol fire extinguishing agent and a fire extinguishing bomb shell assembly, and the fire extinguishing agent comprises an oxidizing agent, a reducing agent, a silicon source film-forming agent, composite anti-corrosion filler, organic acid potassium salt, an adhesive and other components. By optimizing a formula and a process, the prepared fire extinguishing agent has high dispersity and can quickly cover a fire source and interrupt a combustion chain reaction, and the fire extinguishing efficiency is remarkably improved. Meanwhile, the silicon source film-forming agent and the composite anti-corrosion filler have a synergistic effect to form a heat-insulating protective film, so that heat radiation and conduction are reduced, and heat damage to precise instruments and electronic equipment is reduced. The fire extinguishing bomb is particularly suitable for high-rise building fire rescue, has efficient fire extinguishing, low-temperature release and excellent metal protection performance, remarkably improves the fire extinguishing efficiency and reduces secondary damage.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of fire fighting, and particularly relates to a fire-fighting unmanned aerial vehicle (UAV) fire extinguishing bomb and a preparation method thereof. BACKGROUND

[0002] With the rapid growth of high-rise buildings, fire prevention and control is facing severe challenges. Traditional fire-fighting equipment, such as fire engines and ladders, is limited by height, blind area and response speed, and is difficult to meet the rapid rescue needs of high-rise building fires. In particular, the popularity of glass curtain walls and enclosed spaces further increases the difficulty of fire extinguishing. In this context, the technology of fire-fighting UAVs carrying window-breaking fire extinguishing bombs has emerged as the times require. Through flexible deployment in the air, accurate window breaking and rapid release of fire extinguishing agent, the operation limit of traditional equipment is broken, and a new solution is provided for high-rise building fire rescue.

[0003] An aerosol fire extinguishing agent is composed of an oxidizing agent, a reducing agent, a binder and other additives. Its characteristics are that it can quickly generate highly dispersed aerosols, cover the fire source and inhibit the combustion chain reaction. As the core medium of the window-breaking fire extinguishing bomb, the aerosol fire extinguishing agent, with its characteristics of pressureless storage, lightweight and high dispersibility, has become an ideal choice for UAV-borne bombs. The aerosol fire extinguishing agent mainly uses potassium nitrate as an oxidizing agent. Although it has high fire extinguishing performance, the high temperature and high corrosiveness of the aerosol generating agent can cause secondary damage to electrical equipment, precision instruments and documents.

[0004] Therefore, according to the related technology in the above, it is urgent to develop a fire-fighting UAV fire extinguishing agent and a preparation method thereof. SUMMARY

[0005] Therefore, according to the related technology in the above, it is urgent to develop a fire-fighting UAV fire extinguishing agent and a preparation method thereof.

[0006] Based on the above purpose, the present application provides a fire-fighting UAV fire extinguishing bomb and a preparation method thereof.

[0007] A fire-fighting UAV fire extinguishing bomb comprises a solid particle aerosol fire extinguishing agent and a fire extinguishing bomb shell assembly; the fire extinguishing bomb shell assembly adopts an existing UAV throwing device, and comprises a shell, a trigger mechanism and a propulsion device; and the solid particle aerosol fire extinguishing agent is filled in a containing cavity inside the shell.

[0008] A preparation method of a fire-fighting UAV fire extinguishing bomb comprises the following preparation steps:

[0009] S1: Tetraethoxysilane is added to an ethanol solution in a volume ratio of 1:3. During stirring, an acidic catalyst is added, the pH is controlled to 2-3, the temperature is controlled to 15°C-30°C, and the reaction is stirred for 1-2 hours to obtain a silica sol;

[0010] S2: Add the organic silicone resin precursor to the silica sol, adjust the pH to 7-7.5, and continue stirring for 40-60 minutes to obtain a silicon source film-forming agent;

[0011] S3: mixing the anti-corrosion filler powder, hydrophobic silica, and surfactant, adding the mixture to a jet mill, and subjecting the mixture to jet milling treatment to obtain a composite anti-corrosion filler powder;

[0012] S4: adding the composite anti-corrosion filler powder to the silicon source film-forming agent, stirring and mixing evenly, and vacuum drying to obtain a mixture A;

[0013] S5: adding the mixture A into a jet mill, and subjecting the mixture A to jet milling treatment to obtain a powder of the mixture A;

[0014] S6: adding the oxidant into the airflow mill, and obtaining the oxidant powder after airflow milling;

[0015] S7: uniformly mixing the mixture A powder, the oxidant powder, the reducing agent, the organic acid potassium salt and the binder to obtain a mixture B, passing the mixture B through a 100-mesh sieve and granulating to obtain a solid particulate aerosol fire extinguishing agent;

[0016] S8: Fill the solid particulate aerosol fire extinguishing agent into the accommodating cavity of the fire extinguishing bomb shell, seal it, and assemble the trigger mechanism and the propulsion device to obtain the fire extinguishing bomb for the fire-fighting drone.

[0017] Preferably, the solid particulate aerosol fire extinguishing agent comprises the following raw materials in parts by mass: 35-50 parts of oxidant, 15-30 parts of reducing agent, 40-44 parts of silicon source film-forming agent, 7-9 parts of composite anti-corrosion filler powder, 3-8 parts of organic acid potassium salt and 5-12 parts of adhesive.

[0018] Preferably, the oxidant is any one of potassium nitrate, strontium nitrate and potassium perchlorate, and the particle size of the oxidant ranges from 200 μm to 500 μm.

[0019] Preferably, the acidic catalyst is 1M HCl or 0.5M H2SO4.

[0020] Preferably, the organosilane precursor is composed of methyltrimethoxysilane, phenyltrimethoxysilane, vinyltrimethoxysilane, and hexadecyltrimethoxysilane, and the mass ratio of methyltrimethoxysilane, phenyltrimethoxysilane, vinyltrimethoxysilane, and hexadecyltrimethoxysilane is 1:0.5-0.8:0.5-0.8:0.3-0.5.

[0021] Preferably, the ethanol solution is an ethanol aqueous solution in which the volume percentage of ethanol in the solution is 85%.

[0022] Preferably, the mass ratio of the tetraethoxysilane to the silicone resin precursor is 10:2.3-3.6.

[0023] The tetraethoxysilane, as a precursor of the silica sol, is hydrolyzed and condensed under acidic conditions to form a silica sol with a three-dimensional network structure, which provides a basic skeleton for subsequent film formation.

[0024] The organosilane precursor will also undergo a hydrolysis reaction when added to the silica sol under acidic conditions to generate corresponding silanols that continue to undergo condensation reaction with the silica sol to produce an oligomeric siloxane network structure. Through this condensation reaction, the organic groups of the organosilane precursor can be introduced into the siloxane network structure. For example, methyltrimethoxysilane can introduce methyl groups to improve the flexibility, hydrophobicity and adhesion of the siloxane network, making it more suitable for film formation. Phenyltrimethoxysilane can introduce phenyl groups to improve the thermal stability and chemical stability of the film, so that it can still maintain good performance under high temperature conditions. Vinyltrimethoxysilane can introduce organic groups such as vinyl to increase the cross-linking density and mechanical strength of the film, making it less likely to break under high temperature and impact conditions. Hexadecyltrimethoxysilane can introduce long-chain alkyl groups to improve the hydrophobicity of the film.

[0025] Preferably, the surfactant is any one or more of polyglycerol fatty acid ester, polyoxyethylene fatty acid ester, alkyl trimethylammonium bromide and alkyl phosphate potassium salt.

[0026] Preferably, the reducing agent is any one or more of nitroguanidine, urea, melamine and dicyandiamide.

[0027] Preferably, the mass ratio of the basic magnesium carbonate, aluminum silicate, hydrophobic silica, and surfactant is 5:2-4:0.5-1:0.2-0.5.

[0028] The basic magnesium carbonate undergoes a strong endothermic reaction during thermal decomposition, which can significantly reduce the temperature of the low combustion area, inhibit flame propagation, release inert gas CO2 to dilute the oxygen concentration, and release water vapor to improve the conditions for the silanol groups in the silicon source film-forming agent to continue the polycondensation reaction. The generated MgO covers the surface of the fire source, isolates oxygen and reduces heat radiation.

[0029] The aluminum silicate is a material with light weight and excellent chemical stability, low thermal conductivity, high resistance to acid, alkali and oxidant, good chemical inertness, ceramic shell formation under extreme high temperature conditions, good thermal insulation and stability to form a long-lasting fire barrier.

[0030] Preferably, the particle size of the composite resist filler powder is 3-7 μm.

[0031] Preferably, the particle size of the oxidant powder is 2 μm-5 μm.

[0032] Preferably, the organic acid potassium salt is any one or more of potassium acetate, potassium benzoate, potassium citrate and potassium dihydrogen citrate.

[0033] Preferably, the binder is any one or more of nitrocellulose, epoxy resin, phenolic resin and sorbitol.

[0034] Preferably, the particle size of the mixture A powder is 5 μm-8 μm. Controlling the particle size of the mixture A powder to be smaller ensures uniform dispersion in the subsequent mixing process, thereby improving the performance consistency of the film. In the fire extinguishing process, the solid microparticle aerosol extinguishing agent needs to quickly cover the fire source and interrupt the combustion chain reaction. Smaller particle size can improve the dispersibility and covering capacity of the extinguishing agent, enabling it to cover the fire source more quickly and thereby improving the extinguishing efficiency. Smaller particle size can reduce the impact force of the extinguishing agent on surrounding equipment during release, thereby reducing secondary damage.

[0035] Advantages of the present application:

[0036] 1. The solid microparticle aerosol extinguishing agent prepared by the present application can quickly cover the fire source through high-dispersibility aerosol, interrupt the combustion chain reaction, significantly improve the extinguishing efficiency, and is suitable for rapid rescue in complex scenes such as high-rise buildings.

[0037] 2. Through the synergistic effect of the silicon source film forming agent and the composite resist filler, a heat insulation protective film is formed during the fire extinguishing process, reducing heat radiation and conduction and reducing thermal damage to precision instruments and electronic equipment. DETAILED DESCRIPTION

[0038] To make the purpose, technical scheme and advantages of the present application clearer, the present application is further described in detail below with specific examples.

[0039] Example 1:

[0040] A preparation method of a fire extinguishing bomb for a fire-fighting unmanned aerial vehicle, comprising the following preparation steps:

[0041] S1: Add 10 parts of tetraethoxysilane to 85% ethanol solution, with the volume ratio of tetraethoxysilane to ethanol being 1:3. During stirring, add 1M HCl, control the pH to 2, control the temperature at 15°C, and stir the reaction for 1 hour to obtain silica sol;

[0042] S2: 1 part of methyltrimethoxysilane, 0.5 part of phenyltrimethoxysilane, 0.5 part of vinyltrimethoxysilane, and 0.3 part of hexadecyltrimethoxysilane were added to the silica sol, the pH was adjusted to 7, and the mixture was stirred for 40 minutes to obtain a silicon source film-forming agent;

[0043] S3: 5 parts of basic magnesium carbonate, 2 parts of aluminum silicate, 0.5 parts of hydrophobic silica, 0.1 parts of polyglycerol fatty acid ester, and 0.1 parts of polyoxyethylene fatty acid ester were mixed and added to a jet mill. After jet milling, a composite corrosion-resistant filler powder was obtained. The particle size of the composite corrosion-resistant filler powder was 3-6 μm.

[0044] S4: adding 7 parts of the composite anti-corrosion filler powder to 40 parts of the silicon source film-forming agent, stirring and mixing, and vacuum drying to obtain a mixture A;

[0045] S5: adding 45 parts of the mixture A into a jet mill, and after jet milling, obtaining a mixture A powder, wherein the particle size of the mixture A powder is 5 μm-7 μm;

[0046] S6: adding 35 parts of potassium nitrate into a jet mill, and subjecting the mixture to jet milling treatment to obtain an oxidant powder having a particle size of 2 μm to 4 μm;

[0047] S7: Mix 42 parts of mixture A powder, 32 parts of oxidant powder, 10 parts of nitroguanidine, 5 parts of melamine, 2 parts of potassium citrate, 1 part of potassium dihydrogen citrate, 1 part of nitrocellulose, 2 parts of epoxy resin, and 2 parts of phenolic resin to obtain mixture B. Pass mixture B through a 100-mesh sieve and granulate to obtain a solid particulate aerosol fire extinguishing agent.

[0048] S8: Fill the solid particulate aerosol fire extinguishing agent into the accommodating cavity of the fire extinguishing bomb shell, seal it, and assemble the trigger mechanism and the propulsion device to obtain the fire extinguishing bomb for the fire-fighting drone.

[0049] Example 2:

[0050] A method for preparing a fire extinguishing bomb for a fire-fighting drone comprises the following steps:

[0051] S1: Add 10 parts of tetraethoxysilane to 85% ethanol solution, with the volume ratio of tetraethoxysilane to ethanol being 1:3. During stirring, add an acidic catalyst, control the pH to 3, control the temperature to 25°C, and stir the reaction for 1.5 hours to obtain a silica sol;

[0052] S2: 1 part of methyltrimethoxysilane, 0.8 part of phenyltrimethoxysilane, 0.7 part of vinyltrimethoxysilane, and 0.4 part of hexadecyltrimethoxysilane were added to the silica sol, the pH was adjusted to 7, and stirred for 50 minutes to obtain a silicon source film-forming agent;

[0053] S3: 5 parts of basic magnesium carbonate, 3 parts of aluminum silicate, 0.8 parts of hydrophobic silica, 0.2 parts of polyglycerol fatty acid ester, 0.1 parts of alkyl trimethyl ammonium bromide, and 0.1 parts of alkyl phosphate potassium salt were mixed and added to a jet mill. After jet milling, a composite anti-corrosion filler powder was obtained. The particle size of the composite anti-corrosion filler powder was 3-7 μm.

[0054] S4: adding 8 parts of the composite anti-corrosion filler powder to 42 parts of the silicon source film-forming agent, stirring and mixing, and vacuum drying to obtain a mixture A;

[0055] S5: adding 48 parts of the mixture A into a jet mill, and after jet milling, obtaining a mixture A powder, wherein the particle size of the mixture A powder is 5 μm-8 μm;

[0056] S6: adding 42 parts of strontium nitrate into a jet mill, and subjecting the mixture to jet milling treatment to obtain an oxidant powder having a particle size of 2 μm to 5 μm;

[0057] S7: Mix 45 parts of mixture A powder, 40 parts of oxidant powder, 15 parts of nitroguanidine, 2 parts of urea, 3 parts of dicyandiamide, 3 parts of potassium acetate, 2 parts of potassium benzoate, 8 parts of phenolic resin and 2 parts of sorbitol to obtain a mixture B. Pass the mixture B through a 100-mesh sieve and granulate to obtain a solid particulate aerosol fire extinguishing agent;

[0058] S8: Fill the solid particulate aerosol fire extinguishing agent into the accommodating cavity of the fire extinguishing bomb shell, seal it, and assemble the trigger mechanism and the propulsion device to obtain the fire extinguishing bomb for the fire-fighting drone.

[0059] Example 3:

[0060] A method for preparing a fire extinguishing bomb for a fire-fighting drone comprises the following steps:

[0061] S1: Add 10 parts of tetraethoxysilane to 85% ethanol solution, with the volume ratio of tetraethoxysilane to ethanol being 1:3. During stirring, add an acidic catalyst, control the pH to 3, control the temperature to 30°C, and stir the reaction for 2 hours to obtain a silica sol;

[0062] S2: 1 part of methyltrimethoxysilane, 0.8 part of phenyltrimethoxysilane, 0.8 part of vinyltrimethoxysilane, and 0.6 part of hexadecyltrimethoxysilane were added to the silica sol, the pH was adjusted to 7.5, and stirred for 50 minutes to obtain a silicon source film-forming agent;

[0063] S3: 5 parts of basic magnesium carbonate, 4 parts of aluminum silicate, 1.0 part of hydrophobic silica, 0.3 parts of polyoxyethylene fatty acid ester, 0.1 part of alkyl trimethyl ammonium bromide, and 0.1 part of alkyl phosphate potassium salt were mixed and added to a jet mill. After jet milling, a composite anti-corrosion filler powder was obtained. The particle size of the composite anti-corrosion filler powder was 4-7 μm.

[0064] S4: adding 9 parts of the composite anti-corrosion filler powder to 45 parts of the silicon source film-forming agent, stirring and mixing, and vacuum drying to obtain a mixture A;

[0065] S5: adding 52 parts of the mixture A into a jet mill, and subjecting the mixture A to jet milling treatment to obtain a mixture A powder having a particle size of 5 μm to 8 μm;

[0066] S6: adding 40 parts of potassium nitrate and 10 parts of potassium perchlorate into a jet mill, and subjecting the mixture to jet milling treatment to obtain an oxidant powder having a particle size of 2 μm to 5 μm;

[0067] S7: 50 parts of mixture A powder, 46 parts of oxidant powder, 25 parts of nitroguanidine, 5 parts of urea, 5 parts of potassium acetate, 3 parts of potassium citrate, 6 parts of epoxy resin, and 6 parts of phenolic resin are mixed uniformly to obtain mixture B. The mixture B is passed through a 100-mesh sieve and granulated to obtain a solid particulate aerosol fire extinguishing agent;

[0068] S8: Fill the solid particulate aerosol fire extinguishing agent into the accommodating cavity of the fire extinguishing bomb shell, seal it, and assemble the trigger mechanism and the propulsion device to obtain the fire extinguishing bomb for the fire-fighting drone.

[0069] Comparative Example 1:

[0070] Compared with Example 1, steps S6 and S7 are omitted in this comparative example, mixture A is not subjected to gas pulverization treatment to prepare mixture A powder, and the oxide is not subjected to gas pulverization treatment to prepare oxide powder, and is directly used in the next step. The remaining steps and parameters are the same and will not be repeated in this comparative example. Finally, a fire extinguishing bomb for a fire-fighting drone is obtained.

[0071] Comparative Example 2:

[0072] Compared with Example 1, in step S2, after the organosilane precursor was added to the silica sol, the pH was not adjusted to 7. The remaining steps and parameters were the same and will not be repeated in this comparative example. Finally, a fire extinguishing bomb for a fire-fighting drone was obtained.

[0073] Comparative Example 3:

[0074] Compared with Example 1, this comparative example only replaces "basic magnesium carbonate" with "magnesium hydroxide", and the remaining steps and parameters are the same. This comparative example will not be repeated, and finally a fire extinguishing bomb for a fire-fighting drone is obtained.

[0075] Comparative Example 4:

[0076] Compared with Example 1, this comparative example only replaces "aluminum silicate" with "aluminum oxide", and the remaining steps and parameters are the same. This comparative example will not be repeated, and finally a fire extinguishing bomb for a fire-fighting drone is obtained.

[0077] Comparative Example 5:

[0078] Compared with Example 1, this comparative example only replaces "1 part of methyltrimethoxysilane, 0.5 parts of phenyltrimethoxysilane, 0.5 parts of vinyltrimethoxysilane, and 0.3 parts of hexadecyltrimethoxysilane" with "2.3 parts of methyltrimethoxysilane". The remaining steps and parameters are the same, and this comparative example will not be repeated. Finally, a fire extinguishing bomb for a fire-fighting drone is obtained.

[0079] Comparative Example 6:

[0080] Compared with Example 1, this comparative example only replaces "1 part of methyltrimethoxysilane, 0.5 parts of phenyltrimethoxysilane, 0.5 parts of vinyltrimethoxysilane, and 0.3 parts of hexadecyltrimethoxysilane" with "2.3 parts of phenyltrimethoxysilane". The remaining steps and parameters are the same, and this comparative example will not be repeated. Finally, a fire extinguishing bomb for a fire-fighting drone is obtained.

[0081] Comparative Example 7:

[0082] Compared with Example 1, this comparative example only replaces "1 part of methyltrimethoxysilane, 0.5 parts of phenyltrimethoxysilane, 0.5 parts of vinyltrimethoxysilane, and 0.3 parts of hexadecyltrimethoxysilane" with "2.3 parts of vinyltrimethoxysilane". The remaining steps and parameters are the same, and this comparative example will not be repeated. Finally, a fire extinguishing bomb for a fire-fighting drone is obtained.

[0083] Comparative Example 8:

[0084] Compared with Example 1, this comparative example only replaces "1 part of methyltrimethoxysilane, 0.5 parts of phenyltrimethoxysilane, 0.5 parts of vinyltrimethoxysilane, and 0.3 parts of hexadecyltrimethoxysilane" with "2.3 parts of hexadecyltrimethoxysilane". The remaining steps and parameters are the same, and this comparative example will not be repeated. Finally, a fire extinguishing bomb for a fire-fighting drone is obtained.

[0085] Performance testing:

[0086] Test object: fire-fighting unmanned aerial vehicle fire extinguishing bomb prepared by examples 1-3 and comparative examples 1-8, wherein the fire-fighting unmanned aerial vehicle fire extinguishing bomb loaded with solid particle aerosol fire extinguishing agent is 100g.

[0087] Test model: the test model is a steel combustion round tank, the steel combustion round tank has an inner diameter of 20cm, a height of not less than 20cm, and a wall thickness of not less than 3mm, n-heptane is added into the steel round tank, and the liquid level is not less than 50mm from the tank opening.

[0088] Experimental arrangement: a test cabin for constructing a closed fire environment is constructed, the size is 3m long x 3m wide x 3m high, the steel combustion tank is placed in the four corners of the test cabin. A fire-fighting unmanned aerial vehicle fire extinguishing bomb launching port is arranged at the center position of the upper part of the test cabin, and an infrared thermal imager is installed, a thermocouple temperature sensor is arranged at the center position of the ground surface directly below the infrared thermal imager, the highest temperature generated in the center area after explosion is recorded as the center temperature. A steel combustion tank is placed at each of the four corners of the test cabin, and an iron sheet with a size of 100mm long x 50mm wide x 3mm thick is hung at a distance of 50cm from the top of the steel combustion tank. The steel combustion tank is ignited, and after pre-burning for 1min, the fire-fighting unmanned aerial vehicle fire extinguishing bomb is launched. The detailed experimental results are shown in Table 1.

[0089] Subsequent experiment: 30min after launching the fire extinguishing bomb of each group, the steel combustion tank is re-ignited, the steel combustion tank is re-ignited, the iron block at a distance of 50cm from the top of the steel combustion tank is continuously heated for 10min, and after the heating is completed, the combustion tank is closed and naturally cooled. After cooling, the iron sheet is cleaned with a soft brush, dried, and the surface morphology of the iron sheet is observed, and the weight of the iron sheet is weighed to calculate the loss rate. A control group test is set up, an iron sheet with a size of 100mm long x 50mm wide x 3mm thick is hung at the same position of the steel combustion tank, heated for 1min, then cooled for 30min, and then heated for 30min. The detailed experimental results are shown in Table 2.

[0090] Table 1

[0091]

[0092] Table 2

[0093]

[0094]

[0095] The data in Tables 1 and 2 show that the fire-fighting unmanned aerial vehicle fire extinguishing bomb of the present application has high efficiency, low temperature release and excellent metal protection performance, which significantly improves the fire extinguishing efficiency and reduces the secondary damage.

[0096] The traditional aerosol fire extinguishing agent can generate extremely high temperature during the release process, and the high temperature can cause thermal damage to the surrounding electrical equipment, precision instruments and the like. The solid particles (such as metal oxides, carbonates and the like) generated by the aerosol fire extinguishing agent at high temperature are corrosive. For example, the metal oxides such as K2O and KNO2 in the potassium salt aerosol are extremely easy to absorb moisture, and generate strong alkaline substances such as KOH, which have strong corrosiveness to metals, and can not only adhere to the surface of the equipment, but also can enter the inside of the equipment, causing problems such as short circuit of the circuit, damage of the components and the like.

[0097] The fire extinguishing bomb of the present application releases high-dispersible aerosol particles, rapidly spreads and covers the surface of the fire source, utilizes the endothermic decomposition reaction of basic magnesium carbonate at high temperature to generate carbon dioxide, MgO and water, and at the same time, the potassium salt of organic acid (such as potassium acetate, potassium benzoate, potassium citrate and the like) is decomposed at high temperature to generate the corresponding organic acid and potassium salt, which further cooperates with the generated carbon dioxide and water vapor to reduce the high temperature generated by the solid particle aerosol fire extinguishing agent during the release process, reduce the thermal damage to the surrounding equipment and improve the fire extinguishing safety.

[0098] The silicon source film forming agent prepared in the present application is an oligomeric siloxane network structure formed by hydrolysis and condensation reaction of tetraethoxysilane and organosilane precursor. This siloxane network structure will further react with the water vapor generated by the thermal decomposition of basic magnesium carbonate and potassium salt of organic acid and the water vapor in the air to generate a more stable silica network structure, form a heat insulation protective film, isolate oxygen, and at the same time reduce heat radiation and conduction, reduce the thermal damage to the surrounding equipment and the damage of corrosive substances to the equipment. Secondly, different organic groups in the organosilane precursor can endow the film with different properties such as flexibility, hydrophobicity, thermal stability and chemical stability, etc. to adapt to different fire extinguishing environments and needs.

[0099] In addition, the present application is a mixture A powder prepared by mixing the composite anti-etching filler powder and the silicon source film forming agent. The small particle size can improve the dispersibility and covering capacity of the fire extinguishing agent. When the silicon source film forming agent generates a heat insulation protective film, the small particle size of the silicon aluminate and the basic magnesium carbonate and the MgO generated by the endothermic decomposition of the basic magnesium carbonate are dispersed in the heat insulation protective film and on the surface. At 800-1000℃, the aluminum silicate will gradually soften and form a glassy substance, and generate magnesium silicate with magnesium oxide. The melting point of magnesium silicate is about 1500℃, which can remain stable under high temperature conditions. Magnesium silicate has low thermal conductivity, good resistance to acid, alkali and oxidizing agents, and strong chemical inertness, which further improves the corrosion resistance of the protective film, so that it can still maintain good performance in high temperature and corrosive environment.

[0100] Those skilled in the art should understand that the above discussion of any embodiment is merely exemplary in nature and is not intended to imply that the present application is limited to these examples; any of the above embodiments or technical features among different embodiments can be combined, and steps can be implemented in any order, under the idea of the present application, and there are many other changes of different aspects of the present application as described above, which are not provided in details for the sake of brevity.

[0101] The present application is intended to cover all such alternatives, modifications, and variations as come within the scope of the broadest possible interpretation of the appended claims. Accordingly, any and all such alternations, modifications, equivalents, improvements and the like are intended to be encompassed by the present application.

Claims

1. A fire extinguishing bomb for a firefighting drone, comprising a solid particle aerosol fire extinguishing agent and a fire extinguishing bomb shell assembly, wherein the solid particle aerosol fire extinguishing agent is filled in a receiving cavity inside the shell, characterized in that: The solid particulate aerosol fire extinguishing agent comprises the following raw materials in parts by weight: 35-50 parts of an oxidizing agent, 15-30 parts of a reducing agent, 40-44 parts of a silicon source film-forming agent, 7-9 parts of a composite anti-corrosion filler powder, 3-8 parts of an organic acid potassium salt, and 5-12 parts of a binder.

2. The fire extinguishing bomb for a fire-fighting drone according to claim 1, characterized in that: The oxidant is any one of potassium nitrate, strontium nitrate and potassium perchlorate.

3. The fire extinguishing bomb for a fire-fighting drone according to claim 1, characterized in that: The reducing agent is any one or more of nitroguanidine, urea, melamine and dicyandiamide.

4. The fire extinguishing bomb for a fire-fighting drone according to claim 1, characterized in that: Preparation method of the silicon source film-forming agent: A1: Add tetraethoxysilane to an ethanol solution. During stirring, add an acidic catalyst, control the pH to 2-3, and the temperature to 15-30°C. Stir and react for 1-2 hours to obtain a silica sol. A2: Add the organic silicone resin precursor to the silica sol, adjust the pH to 7-7.5, and continue stirring for 40-60 minutes to obtain a silicon source film-forming agent.

5. The fire extinguishing bomb for a fire-fighting drone according to claim 1, characterized in that: The organosilane precursor consists of methyltrimethoxysilane, phenyltrimethoxysilane, vinyltrimethoxysilane and hexadecyltrimethoxysilane, and the mass ratio of methyltrimethoxysilane, phenyltrimethoxysilane, vinyltrimethoxysilane and hexadecyltrimethoxysilane is 1:0.5-0.8:0.5-0.8:0.3-0.

5.

6. The fire extinguishing bomb for a fire-fighting drone according to claim 1, characterized in that: The preparation method of the composite anti-corrosion filler powder comprises the following steps: mixing basic magnesium carbonate, aluminum silicate, hydrophobic silicon dioxide and a surfactant, adding the mixture into a jet mill, and subjecting the mixture to jet milling treatment to obtain the composite anti-corrosion filler powder.

7. The fire extinguishing bomb for a firefighting drone according to claim 6, characterized in that: The mass ratio of the basic magnesium carbonate, aluminum silicate, hydrophobic silicon dioxide and surfactant is 5:2-4:0.5-1:0.2-0.

5.

8. The fire extinguishing bomb for a firefighting drone according to claim 1, characterized in that: The organic acid potassium salt is any one or more of potassium acetate, potassium benzoate, potassium citrate and potassium dihydrogen citrate.

9. The fire extinguishing bomb for a firefighting drone according to claim 1, characterized in that: The adhesive is any one or more of nitrocellulose, epoxy resin, phenolic resin and sorbitol.

10. A method for preparing a fire extinguishing bomb for a fire-fighting drone according to any one of claims 1 to 9, characterized in that The following steps are involved: Step S1: adding the composite anti-corrosion filler powder to the silicon source film-forming agent, stirring and mixing until uniform, and vacuum drying to obtain a mixture A; Step S2: adding the mixture A into a jet mill and subjecting it to jet milling treatment to obtain a powder of the mixture A; Step S3: adding the oxidant into the airflow mill, and subjecting the oxidant to airflow milling treatment to obtain oxidant powder; Step S4: uniformly mixing the mixture A powder, the oxidant powder, the reducing agent, the organic acid potassium salt and the binder to obtain a mixture C, sieving the mixture C and granulating it to obtain a solid particulate aerosol fire extinguishing agent; Step S5: Fill the solid particulate aerosol fire extinguishing agent into the accommodating cavity of the fire extinguishing bomb shell, seal it, and assemble the trigger mechanism and the propulsion device to obtain the fire extinguishing bomb for the fire-fighting drone.

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