Dry powder extinguishing agent and preparation method thereof

Abstract

The invention discloses a dry powder extinguishing agent and a preparation method thereof. The dry powder extinguishing agent comprises the following components in percentage by mass: 10-95% of basic aluminum carbonate, 0-85% of bicarbonate or ammonium phosphate, 2-5% of a lubricant, 2-5% of a moisture-proof agent, 2-5% of a flow aid and 2-5% of other auxiliaries. According to the dry powder extinguishing agent with the basic aluminum carbonate as the main component, the problem that a commercially available dry powder extinguishing agent is difficult to effectively inhibit high-temperature environment fire disasters can be solved, and the dry powder extinguishing agent with the basic aluminum carbonate and an existing dry powder effective component compounded component as the main component can achieve the high-low temperature full-temperature-zone effect of the dry powder extinguishing agent; the fire extinguishing efficiency of the dry powder extinguishing agent is improved, and the application range of the dry powder extinguishing agent is expanded.

Description

Technical Field

[0001] The invention belongs to the field of fire extinguishing agents and relates to a dry powder fire extinguishing agent and a preparation method thereof. Background Art

[0002] Dry powder fire extinguishing agent has the characteristics of long service life, high fire extinguishing efficiency, low price, low toxicity and environmental friendliness. It is a type of halon substitute widely used in the field of fire protection engineering. However, since the currently used ammonium phosphate dry powder fire extinguishing agent and bicarbonate dry powder fire extinguishing agent partially or completely decompose at around 155°C, they are prone to failure when stored in high temperature environment for a long time, which limits the application of dry powder fire extinguishing agent. In order to expand the application scope of dry powder fire extinguishing agent, finding new high temperature resistant fire extinguishing effective components has become one of the development hotspots in the current fire protection field.

[0003] Basic aluminum carbonate has good flame retardant effect, low toxicity of pyrolysis products, smoke elimination, no migration and mechanical reinforcement to the base material, and is used as a flame retardant filler for polymer materials. Adding basic aluminum carbonate to plastics can not only make the plastics flame retardant, but also significantly reduce the acidic smoke produced when the plastics are burned. For example, when polyvinyl chloride composite materials are exposed to flames, the basic aluminum carbonate in them can eliminate hydrogen chloride gas. During the combustion process, basic aluminum carbonate plays a flame retardant role in both the gas phase and the condensed phase, especially in promoting carbonization, forming an insulating layer on the surface of the substrate, and preventing the exchange of oxygen and heat, which can effectively protect the substrate. In addition, due to its low alkalinity, basic aluminum carbonate has been widely used in the field of aluminum-containing chemicals, as well as in antacids, corrosion inhibitors, solid base catalysts, etc.

[0004] Chinese patent CN 114773776A discloses a polyoxymethylene granular material of a halogen-free intumescent flame retardant system, comprising 57-63.5% polyoxymethylene, 6-10% melamine polyphosphate, 4-7% basic sodium aluminum carbonate, 0.5-1.5% processing aid, and the rest being phosphorus-nitrogen flame retardant. The material can be used in flame-retardant polyoxymethylene parts and accessories in the fields of fire protection, petrochemicals, metallurgy, etc., such as the use of fire-retardant zippers in fire-retardant clothing.

[0005] Chinese patent CN 106243709 A discloses a polyphenylphosphonic acid diphenyl sulfone ester synergistic basic aluminum magnesium carbonate flame retardant cable material, including nylon 6643-56%, halogenated bisphenol A polycarbonate 31-44%, poly 2,6-dibromophenyl ether 24-37%, tridecyl benzyl ester 13-17%, polyphenylphosphonic acid diphenyl sulfone ester 12-16%, skarn 15-20%, calcium montanate 3-4%, cordierite 9-18%, basic aluminum magnesium carbonate 7-12%, talc 13-19%, N-ethyl p-toluenesulfonamide 12-18%, tris(2,3-dichloropropyl) phosphate 10-15%, candelilla wax 5-9%, brucite fiber 10-15%, which has the advantages of excellent flame retardant performance, low smoke emission, high oxygen index, good heat resistance, high mechanical strength, etc. Summary of the invention

[0006] The purpose of the present invention is to provide a dry powder fire extinguishing agent and a preparation method thereof, which has the characteristics of high temperature resistance, high fire extinguishing efficiency and wide application range, which not only solves the limitations of the use of dry powder fire extinguishing agents in high temperature environments, but also improves the fire extinguishing efficiency of existing dry powder fire extinguishing agents.

[0007] The technical solution for achieving the purpose of the present invention is as follows:

[0008] A dry powder fire extinguishing agent comprises, by mass percentage, 10-95% of basic aluminum carbonate salt, 0-85% of bicarbonate or ammonium phosphate salt, 2-5% of lubricant, 2-5% of moisture-proof agent, 2-5% of flow aid, and 2-5% of other auxiliary agents.

[0009] Preferably, the basic aluminum carbonate salt is one or more of basic sodium aluminum carbonate, basic potassium aluminum carbonate or basic magnesium aluminum carbonate.

[0010] In the present invention, bicarbonate or ammonium phosphate is the main component of commercially available dry powder fire extinguishing agent.

[0011] Preferably, the bicarbonate is selected from one or both of sodium bicarbonate and potassium bicarbonate.

[0012] Preferably, the ammonium phosphate salt is selected from one or more of diammonium phosphate, diammonium hydrogen phosphate, ammonium pyrophosphate, ammonium sulfate and ammonium polyphosphate.

[0013] The lubricant described in the present invention is a common lubricant in dry powder fire extinguishing agent, such as mica powder, talcum powder and the like.

[0014] The moisture-proofing agent described in the present invention is a moisture-proofing agent commonly used in dry powder fire extinguishing agents, such as magnesium stearate, hydrophilic fumed silica, and the like.

[0015] The flow aid described in the present invention is a common flow aid in dry powder fire extinguishing agents, such as methylethoxy silicone oil, methyltrifluoropropyl silicone oil, methylvinyl silicone oil, methylhydroxy silicone oil, etc.

[0016] The other additives described in the present invention are other additives commonly used in dry powder fire extinguishing agents, such as activated clay, artificial zeolite, nano calcium carbonate, etc.

[0017] Preferably, the dry powder fire extinguishing agent comprises, by mass percentage, 90% basic sodium aluminum carbonate or basic potassium aluminum carbonate, 2% to 3% talc, 2% to 3% magnesium stearate, 2% to 4% methylethoxy silicone oil, and 2% activated white clay.

[0018] Preferably, the dry powder fire extinguishing agent comprises, by mass percentage, 65% basic sodium aluminum carbonate, 12% diammonium phosphate, 3% ammonium sulfate, 5% talc, 5% magnesium stearate, 5% methylethoxy silicone oil, and 5% activated white clay.

[0019] Preferably, the dry powder fire extinguishing agent comprises, by mass percentage, 10% basic sodium aluminum carbonate, 80% sodium bicarbonate, 3% talcum powder, 3% magnesium stearate, 2% methylethoxy silicone oil, and 2% activated white clay.

[0020] The preparation method of the above dry powder fire extinguishing agent comprises the following steps:

[0021] (1) According to the proportion, basic aluminum carbonate, bicarbonate or ammonium phosphate, lubricant, and moisture-proof agent are fully crushed in a crusher to obtain a fine mixture powder;

[0022] (2) The mixed powder, flow aid and other auxiliary agents are dispersed by high-speed stirring, mixed evenly, and dried to obtain a dry powder fire extinguishing agent.

[0023] Preferably, in step (1), a pulverizer is used for pulverization, wherein the blade speed is 18000-20000 r / min, the air flow pressure is 0.6-0.8 MPa, and the air flow rate is 2.8-3.5 m 3 / min, the feeding speed is 6-8kg / h, and the crushing time is 30-60min.

[0024] Preferably, in step (2), the stirring speed is 2000-3000 r / min, the stirring time is 0.5-2 h, and the treatment temperature is 50-65°C.

[0025] Preferably, in step (2), the water is dried and then sieved to collect D 90 The powder below 20μm can obtain ultra-fine dry powder fire extinguishing agent.

[0026] Compared with the prior art, the present invention has the following advantages:

[0027] (1) The present invention is the first to apply basic aluminum carbonate salt to dry powder fire extinguishing agents. The decomposition temperature of basic aluminum carbonate salt is about 320°C. It captures free radicals when heated to quickly extinguish flames. The solid matter produced by decomposition covers the surface of combustibles, which can effectively insulate and suffocate fires. The water and carbon dioxide produced can effectively dilute the concentration of combustibles and reduce the oxygen concentration. The dry powder fire extinguishing agent with basic aluminum carbonate salt as the main component can solve the problem that commercially available dry powder fire extinguishing agents are difficult to effectively suppress fires in high-temperature environments.

[0028] (2) There are usually various complex situations at the fire scene, and the fire development is characterized by rapid development and irregularity, resulting in different temperature zones at the fire scene. The dry powder fire extinguishing agent with a compound component of basic aluminum carbonate and existing dry powder effective components (bicarbonate or ammonium phosphate) as the main component can achieve the full temperature range of high and low temperature of the dry powder fire extinguishing agent, improve the fire extinguishing efficiency of the dry powder fire extinguishing agent, and expand the application scope of the dry powder fire extinguishing agent. It has broad application prospects in the fields of metallurgy, petrochemicals, chemicals, nuclear industry, aerospace, and ships. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a scanning electron microscope image of the ultrafine dry powder fire extinguishing agent in Example 1;

[0030] Figure 2 is the infrared spectrum of the ultrafine dry powder fire extinguishing agent in Example 1;

[0031] Figure 3 is the X-ray diffraction pattern of the ultrafine dry powder fire extinguishing agent in Example 1;

[0032] Figure 4 This is the thermal weight loss diagram of the ultrafine dry powder fire extinguishing agent in Example 1;

[0033] Figure 5 FIG. 1 is a diagram of using the ultrafine dry powder fire extinguishing agent in Example 1 to extinguish aviation kerosene fire;

[0034] Figure 6 This is a scanning electron microscope image of the ultrafine dry powder fire extinguishing agent in Example 3;

[0035] Figure 7 This is a diagram of the ultrafine dry powder fire extinguishing agent in Example 3 extinguishing aviation kerosene fire. DETAILED DESCRIPTION

[0036] In order to further illustrate the present invention, the following is a clear and detailed description of a dry powder fire extinguishing agent and a preparation method thereof provided by the present invention in combination with embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all embodiments.

[0037] It should be noted that, in the embodiments, those without specifying specific conditions are carried out according to normal conditions or conditions recommended by the manufacturer. Those without specifying the manufacturer for reagents or instruments used are conventional products that can be purchased commercially. In addition, the meaning of "and / or" appearing in the full text includes three parallel schemes, and "A and / or B" is taken as an example, including schemes A, B, or A and B that meet the same time. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative work premise belong to the scope of protection of the present invention. In addition, the technical schemes between the various embodiments can be combined with each other, but must be based on those of ordinary skill in the art can be realized, when the combination of the technical schemes appears mutually contradictory or cannot be realized, it should be considered that the combination of such technical schemes does not exist, and is not within the scope of protection required by the present invention.

[0038] In the following examples, the basic aluminum carbonate salts used were prepared according to patents US04221771, US4356157 and US05078983.

[0039] Example 1

[0040] 90 parts of basic sodium aluminum carbonate, 2 parts of talc, and 2 parts of magnesium stearate were fully crushed in a supersonic airflow mill to obtain a mixture; the mixture was stirred and dispersed with 4 parts of methylethoxy silicone oil and 2 parts of activated clay at high speed for 2 hours at a temperature of 55°C, and the water was dried and screened after stirring again. 90 (Particle cumulative distribution is 90% of the particle size) is below 20μm, obtaining an ultra-fine dry powder fire extinguishing agent.

[0041] Example 2

[0042] 90 parts of potassium aluminum carbonate, 3 parts of talc and 3 parts of magnesium stearate were fully crushed in a supersonic airflow mill to obtain a mixture; the mixture was stirred and dispersed with 2 parts of methylethoxy silicone oil and 2 parts of activated clay at high speed for 2 hours at a temperature of 55°C, and then stirred again to be uniform and dried to measure the moisture content. 90 If the particle size is larger than 20 μm, a dry powder fire extinguishing agent is obtained.

[0043] Example 3

[0044] 65 parts of basic sodium aluminum carbonate, 12 parts of ammonium dihydrogen phosphate, 3 parts of ammonium sulfate, 5 parts of talc and 5 parts of magnesium stearate were fully crushed in a supersonic airflow mill to obtain a mixture; the mixture was stirred and dispersed with 5 parts of methylethoxy silicone oil and 5 parts of activated clay at high speed for 2 hours at a temperature of 55°C, and the water content was dried after stirring again and screened. 90 Below 20μm, ultra-fine dry powder fire extinguishing agent is obtained.

[0045] Example 4

[0046] 65 parts of basic sodium aluminum carbonate, 12 parts of ammonium dihydrogen phosphate, 3 parts of ammonium sulfate, 5 parts of talc and 5 parts of magnesium stearate were fully crushed in a supersonic airflow mill to obtain a mixture; the mixture was stirred and dispersed with 5 parts of methylethoxy silicone oil and 5 parts of activated white clay at high speed for 2 hours at a temperature of 55°C, and then stirred again to be uniform and dried to measure the moisture content. 90 If the particle size is larger than 20 μm, a dry powder fire extinguishing agent is obtained.

[0047] Example 5

[0048] 10 parts of basic sodium aluminum carbonate, 80 parts of sodium bicarbonate, 3 parts of talc and 3 parts of magnesium stearate were fully crushed in a supersonic airflow mill to obtain a mixture; the mixture was stirred and dispersed with 2 parts of methylethoxy silicone oil and 2 parts of activated white clay at high speed for 2 hours at a temperature of 55°C, and the water was dried after stirring again and screened. 90 Below 20μm, ultra-fine dry powder fire extinguishing agent is obtained.

[0049] Example 6

[0050] 10 parts of basic sodium aluminum carbonate, 80 parts of sodium bicarbonate, 3 parts of talc and 3 parts of magnesium stearate were fully crushed in a supersonic airflow mill to obtain a mixture; the mixture was stirred and dispersed with 2 parts of methylethoxy silicone oil and 2 parts of activated white clay at high speed for 2 hours at a temperature of 55°C, and then stirred again to be uniform and dried to measure the moisture content. 90 If the particle size is larger than 20 μm, a dry powder fire extinguishing agent is obtained.

[0051] Comparative Example 1

[0052] This comparative example is basically the same as Example 1, except that the mass of basic sodium aluminum carbonate is 0 parts, the mass of diammonium phosphate is 80 parts, the mass of ammonium sulfate is 10 parts, talc is 2 parts, magnesium stearate is 2 parts, methylethoxy silicone oil is 4 parts, and activated white clay is 2 parts.

[0053] The fire extinguishing effect of the dry powder fire extinguishing agents obtained in Examples 1 to 6 and Comparative Example 1 on suppressing n-heptane oil pool fire was tested under the same test conditions, and the results are shown in Table 1. As can be seen from Table 1, the fire extinguishing efficiency of the ultrafine dry powder fire extinguishing agent is higher than that of the non-ultrafine dry powder fire extinguishing agent; the larger the mass ratio of the basic aluminum carbonate salt, the less the amount of dry powder fire extinguishing agent used and the shorter the fire extinguishing time.

[0054] Table 1 Fire extinguishing effect test results

[0055] Example Fire extinguishing agent dosage / g Fire extinguishing time / s Example 1 20.2 5.2 Example 2 22.4 5.5 Example 3 22.3 6.5 Example 4 25.3 5.8 Example 5 23.9 6.9 Example 6 25.8 7.1 Comparative Example 1 27.0 7.6

[0056] Figure 1 , 6The microscopic morphologies of a dry powder fire extinguishing agent whose main component is sodium aluminum carbonate and a dry powder fire extinguishing agent whose main components are a compound of sodium aluminum carbonate and ammonium phosphate are shown respectively. In comparison, the dry powder fire extinguishing agent whose main component is sodium aluminum carbonate has the characteristics of small particle size and uniform distribution. Figure 2 , 3 ,4 The synthesis results of sodium aluminum carbonate were accurately verified through material structure detection and thermogravimetric analysis. Figure 5 , 7 These are the actual pictures of a dry powder fire extinguishing agent whose main component is sodium aluminum carbonate and a dry powder fire extinguishing agent whose main components are a mixture of sodium aluminum carbonate and ammonium phosphate salts extinguishing n-heptane oil pool fire at the same time. In comparison, small particles of sodium aluminum carbonate have better dispersion during the fire extinguishing process, and the dry powder cloud surrounds the flame faster, which is one of the reasons for its high fire extinguishing efficiency.

Claims

1. A dry powder fire extinguishing agent, characterized in that: Calculated by mass percentage, it includes 10~95% basic aluminum carbonate, 0~85% bicarbonate or ammonium phosphate, 2~5% lubricant, 2~5% moisture-proof agent, 2~5% flow aid, and 2~5% other additives.

2. The dry powder fire extinguishing agent according to claim 1, characterized in that: The basic aluminum carbonate salt is one or more of basic aluminum carbonate sodium, basic aluminum carbonate potassium or basic aluminum carbonate magnesium, with an average particle size of less than 10 μm, and the average particle size of the bicarbonate or ammonium phosphate salt is less than 20 μm.

3. The dry powder fire extinguishing agent according to claim 1, characterized in that: The bicarbonate is selected from one or both of sodium bicarbonate and potassium bicarbonate, and the ammonium phosphate is selected from one or more of diammonium phosphate, diammonium hydrogen phosphate, ammonium pyrophosphate, ammonium sulfate and ammonium polyphosphate.

4. The dry powder fire extinguishing agent according to claim 1, characterized in that: The lubricant is mica powder or talc powder, the moisture-proof agent is magnesium stearate or hydrophilic fumed silica, the flow aid is methylethoxy silicone oil, methyltrifluoropropyl silicone oil, methylvinyl silicone oil or methylhydroxy silicone oil, and the other additives are activated clay, artificial zeolite or nano calcium carbonate.

5. The dry powder fire extinguishing agent according to claim 1, characterized in that: Calculated by mass percentage, it includes 90% basic sodium aluminum carbonate or basic potassium aluminum carbonate, 2%~3% talc, 2%~3% magnesium stearate, 2%~4% methylethoxy silicone oil, and 2% activated white clay.

6. The dry powder fire extinguishing agent according to claim 1, characterized in that: Calculated by mass percentage, it includes 65% basic sodium aluminum carbonate, 12% diammonium phosphate, 3% ammonium sulfate, 5% talc, 5% magnesium stearate, 5% methylethoxy silicone oil, and 5% activated white clay.

7. The dry powder fire extinguishing agent according to claim 1, characterized in that: Calculated by mass percentage, it includes 10% basic sodium aluminum carbonate, 80% sodium bicarbonate, 3% talc, 3% magnesium stearate, 2% methylethoxy silicone oil, and 2% activated white clay.

8. The method for preparing a dry powder fire extinguishing agent according to any one of claims 1 to 7, characterized in that: The following steps are involved: (1) According to the proportion, basic aluminum carbonate, bicarbonate or ammonium phosphate, lubricant and moisture-proof agent are fully crushed in a crusher to obtain a fine mixture powder; (2) The mixed powder is dispersed with the flow aid and other additives by high-speed stirring, mixed evenly, and dried to obtain a dry powder fire extinguishing agent.

9. The preparation method according to claim 8, characterized in that: In step (1), the pulverization is carried out by using a supersonic air flow pulverizer, wherein the blade speed is 18000-20000 r / min, the air flow pressure is 0.6-0.8 MPa, and the air flow rate is 2.8-3.5 m 3 / min, the feeding speed is 6-8kg / h, and the crushing time is 30-60min; in step (2), the stirring speed is 2000-3000r / min, the stirring time is 0.5-2h, and the processing temperature is 50-65°C.

10. The preparation method according to claim 8, characterized in that: In step (2), the water is dried and then sieved to collect D 90 The powder below 20μm can obtain ultra-fine dry powder fire extinguishing agent.

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