A composite dry water explosion suppressant for suppressing organic dust explosion and its preparation method

Abstract

The present invention relates to the technical field of explosion suppressants, and provides a composite dry water explosion suppressant for suppressing organic dust explosions and a preparation method thereof. The composite dry water explosion suppressant comprises the following raw materials by weight: 100 ml of deionized water, 10 g of hydrophobic fumed silica, 0.772 g of ammonium polyphosphate, 1.487 g of cobalt nitrate hexahydrate, 1.602 g of dimethylimidazole, and 200 ml of methanol, wherein the particle size of the hydrophobic fumed silica, ammonium polyphosphate, cobalt nitrate hexahydrate, and dimethylimidazole are all less than 5 μm. The composite dry water explosion suppressant provided by the present invention has the advantages of good explosion suppression and explosion prevention performance, low usage, and high explosion suppression efficiency. It can effectively slow down the overall combustion rate and explosion speed, achieve the effect of significantly increasing the resistance to the propagation of the explosion reaction, and also form a flame retardant and explosion prevention effect in the early stage of matrix combustion.

Description

Technical Field

[0001] The present invention relates to the technical field of explosion suppressants, and more particularly to a composite dry water explosion suppressant for suppressing organic dust explosions and a preparation method thereof. Background Art

[0002] Organic dust explosions are a serious safety issue in industrial production. Organic dusts, such as PMMA dust, biomass dust (poplar sawdust and peanut shell dust), and coal dust, are very likely to cause explosions under certain conditions.

[0003] Explosion suppression technology, as an effective means of controlling dust explosions, can reduce their scale in the early stages and even prevent them from occurring. The core of dust explosion suppression technology lies in the research and development of explosion suppressants with superior explosion suppression performance. Therefore, actively exploring theories for the prevention and control of organic dust explosions and formulating effective explosion prevention measures are crucial to the production safety of enterprises.

[0004] Currently, research on powder explosion suppression materials focuses on suppressing explosions using a single substance, such as rock dust, CaCO3, Na2CO3, and Al(OH)3. Studies have shown that composite powder explosion suppressants formed from a combination of multiple substances can exert a coupled explosion suppression effect during the explosion suppression process, resulting in better explosion suppression results. The development of composite powder explosion suppressants using industrial solid waste can better address the issue of waste resource recycling and provide new solutions to the safety issues of industrial dust explosion suppression.

[0005] Based on this, the present application proposes a composite dry water explosion suppressant for suppressing organic dust explosions and a preparation method thereof. Summary of the Invention

[0006] The purpose of the present invention is to provide a composite dry water explosion suppressant for suppressing organic dust explosion and a preparation method thereof, thereby enhancing the performance of dust explosion suppression and explosion prevention.

[0007] To solve the above technical problems, the present invention is achieved through the following technical solutions:

[0008] In one aspect, the present invention provides a composite dry water explosion suppressant for suppressing organic dust explosions. The composite dry water explosion suppressant comprises the following raw materials in parts by weight:

[0009] 100 ml of deionized water, 10 g of hydrophobic fumed silica, 0.772 g of ammonium polyphosphate, 1.487 g of cobalt nitrate hexahydrate, 1.602 g of dimethylimidazole, and 200 ml of methanol, wherein the particle sizes of the hydrophobic fumed silica, ammonium polyphosphate, cobalt nitrate hexahydrate, and dimethylimidazole are all less than 5 μm.

[0010] On the other hand, the present invention provides a method for preparing a composite dry water explosion suppressant, and the specific preparation steps are as follows:

[0011] Raw material preparation stage: First, accurately weigh 1.487g of cobalt nitrate hexahydrate, 1.602g of dimethylimidazole, and 0.772g of ammonium polyphosphate, and set them aside for later use;

[0012] Solvent preparation stage: Next, accurately measure 50ml, 50ml, and 100ml of methanol solution respectively according to the volume ratio of 1:1:2, and set them aside for later use;

[0013] Mixing reaction stage: Weighed cobalt nitrate hexahydrate, dimethylimidazole, and ammonium polyphosphate are added to the pre-measured methanol solution in sequence and stirred for 2 hours to obtain solution A, solution B, and solution C. After stirring, solution A is first poured into solution B and stirred continuously, and then mixed with solution C and stirred for another 2 hours to ensure thorough mixing.

[0014] Filtration and drying stage: The mixed raw materials are filtered and washed through a filter device to remove impurities; the washed solids are placed in a vacuum drying oven and dried at 60°C for 24 hours; after drying, the solids are removed and ground for subsequent use. The resulting solid powder is the ZIF-67 and APP composite material APP-Co-ZIF;

[0015] Preparation of the composite dry water explosion suppressant: Weigh 10g of hydrophobic fumed silica and 100ml of deionized water. Add 2g of ground powder to the deionized water and add the hydrophobic fumed silica. Stir at 6000 rpm for 90 seconds using a high-speed stirrer. The desired composite dry water explosion suppressant is obtained.

[0016] Beneficial effects of the present invention:

[0017] The composite dry water explosion suppressant provided by the present invention can block the contact between coal powder and oxygen. Through the combined action, it absorbs heat, dilutes combustible gases, consumes free radicals, and forms a carbon layer covering the surface of the coal powder, preventing contact with the outside world, so that the coal powder explosion cannot continue, and ultimately achieves the effect of explosion suppression and explosion prevention.

[0018] The composite dry water explosion suppressant provided by the present invention can reduce the ambient temperature in real time during coal seam combustion and explosion through the endothermic decomposition of APP-Co-ZIF powder, achieving the effect of competing coal to release heat during pyrolysis and gasification, effectively reducing the overall combustion and explosion speeds, and significantly increasing the resistance to the propagation of the explosion reaction.

[0019] The composite dry water explosion suppressant provided by the present invention can achieve a safety protection effect in the early stage of combustion. It uses APP-Co-ZIF powder to decompose into a non-combustible carbon layer under heat and coat the surface of the substrate, while promoting the rapid formation of residual carbon, thereby forming a flame retardant and explosion-proof effect in the early stage of substrate combustion. DETAILED DESCRIPTION

[0020] The present invention will be described in detail below with reference to the following examples. However, it should be understood that the following examples are merely illustrative of the embodiments of the present invention and are not intended to limit the scope of the present invention.

[0021] The specific explosion suppression mechanism of the composite dry water explosion suppressant for suppressing organic dust explosion provided by the present invention is:

[0022] Taking coal powder as an example, first of all, dry water explosion suppressant is a new type of capsule-shaped explosion suppressant containing a soluble powder explosion suppressant aqueous solution wrapped by hydrophobic fumed silica. Its water content is as high as 90%. Therefore, its structure will be destroyed in high-temperature environments such as explosion or thermal decomposition. Water molecules will evaporate and absorb a large amount of heat, effectively lowering the temperature of the reaction system, thereby reducing coal powder explosion; in addition, silica, as an inert material, covers the surface of coal powder, which can block the contact between coal powder and oxygen, thereby suppressing coal powder explosion.

[0023] ZIF-67 and the composite material APP-Co-ZIF have a large specific surface area. The adsorption capacity of ZIF-67 on the surface of APP-Co-ZIF can absorb heat and gas in the system, reducing the risk of combustion and explosion in the system. During the combustion and explosion of coal dust, APP-Co-ZIF powder absorbs heat and decomposes, which can lower the immediate temperature of the surrounding environment. This endothermic behavior competes with the heat released by coal during pyrolysis and gasification, effectively slowing down the overall combustion and explosion rate in the spherical combustion chamber. At the same time, the thermal decomposition of APP-Co-ZIF powder produces NH3 and water vapor, which can dilute the oxygen in the explosion system and the combustible gases produced by coal pyrolysis. This makes the continuous combustion and explosion reactions in the combustion chamber severely hindered, making it more difficult to spread.

[0024] APP-Co-ZIF decomposes into phosphate derivatives such as polyphosphoric acid and metaphosphoric acid upon heating. These phosphate derivatives catalyze the cross-linking of polymers into carbon, dehydrating and carbonizing the substrate surface to form a non-combustible carbon layer covering the substrate surface, acting as a physical barrier, delaying the exchange of combustible substances and the conduction of heat energy, and reducing the decomposition rate of the internal matrix. In addition, due to the presence of cobalt ions, Co2+ in APP-Co-ZIF promotes the rapid generation of P-OH, allowing structures such as PO-Co-OC and POC to form earlier, thereby promoting the rapid formation of residual carbon, thus playing a safety protection role in the early stages of combustion. With the increase in temperature and the release of H2O and NH3, more POC, phosphorylated cross-linked structures, and CoOx are generated on the carbon layer, and a dense and stable carbon layer composed of POC, C=C, CN, CoOx, etc. is gradually formed, achieving a good barrier effect during the combustion process.

[0025] Furthermore, the phosphate derivatives obtained by the decomposition of APP-Co-ZIF during the combustion process will undergo disproportionation reactions to generate HPO·, PO2· and PO· free radicals. These free radicals can capture the H· and OH· free radicals produced by the polymer chain reaction, exert a quenching effect, and reduce heat release; therefore, the composite explosion suppressant's mechanism of suppressing coal powder explosion combines the effects of dry water and APP-Co-ZIF itself with the structural characteristics of the imidazole metal-organic framework material and the synergistic effects brought by cobalt ions, including physical and chemical effects. Through the joint action, it absorbs heat, dilutes combustible gases, consumes free radicals, and forms a carbon layer covering the surface of the coal powder, preventing contact with the outside world, and ultimately achieving the effect of suppressing explosion.

[0026] In the above explosion suppression mechanism, the comprehensive suppression effect of various materials prevents the coal powder explosion from continuing, ultimately achieving the purpose of suppressing the coal powder explosion, and making it have excellent explosion suppression and explosion-proof performance in an explosive coal powder explosion environment.

[0027] In the above textual description of the explosion suppression mechanism of the composite dry water explosion suppressant, the main chemical reaction equations involved are as follows:

[0028] NH4+OH→OH+H2O

[0029] NH3+H+→NH2+H2

[0030] NH2+O2→NHO+OH

[0031] NH3+OH→NH2+H2O

[0032] H3PO4→HPO3+PO+HPO

[0033] PO+H→HPO

[0034] HPO+H→H2+PO

[0035] PO+OH→HPO+O

[0036] PO+OH+H2→HPO+H2O

[0037] PO+Co→POCo

[0038] CO + O → CoO

[0039] Experiment 1

[0040] The raw material formula of the explosion suppressant for suppressing coal powder explosion is: 10g hydrophobic fumed silica and 100ml deionized water.

[0041] Preparation method: Hydrophobic fumed silica is mixed with deionized water and stirred in a high-speed disperser at a speed of 6000 r / min for 90 seconds to obtain a common dry water explosion suppressant;

[0042] The minimum amount of the common dry water explosion suppressant for suppressing organic dust explosion required to suppress coal dust explosion was determined using a 20L explosion ball test system. The experimental results are shown in Table 1.

[0043] Experiment 2

[0044] The raw material formula of APP composite dry water explosion suppressant for suppressing coal powder explosion is: hydrophobic fumed silica, deionized water, and ammonium polyphosphate;

[0045] Preparation method: Weigh 2g of ammonium polyphosphate and add 100ml of deionized water and stir evenly, then add 10g of silicon dioxide, and then mix in a high-speed disperser at a speed of 6000r / min and stir for 90s to obtain APP composite dry water explosion suppressant;

[0046] The minimum amount of the explosion suppressant for suppressing the organic dust explosion required to suppress the coal dust explosion was determined using a 20L explosion ball test system. The experimental results are shown in Table 1.

[0047] Experiment 3

[0048] A 20L explosive ball experimental system was used to test the composite dry water explosion suppressant for suppressing organic dust explosions provided by the present invention.

[0049] The minimum amount of the composite dry water explosion suppressant for suppressing organic dust explosions required to suppress coal dust explosions was determined using a 20L explosion ball test system. The experimental results are shown in Table 1.

[0050]

[0051] Table 1

[0052] As can be seen from Table 1 above, from Experiment 1 to Experiment 3, the amount of composite dry water explosion suppressant required to completely suppress the coal powder explosion is the lowest.

[0053] It can be understood that the composite dry water explosion suppressant for suppressing organic dust explosions in the above technical solution has the advantages of good explosion suppression and explosion protection performance, small dosage and high explosion suppression efficiency. Compared with the existing technology, it has more outstanding advantages and provides a new idea for suppressing organic dust explosions.

[0054] With the above-described preferred embodiments of the present invention as a guide, and with reference to the above description, relevant personnel are fully capable of making various changes and modifications without departing from the technical scope of this invention. The technical scope of this invention is not limited to the contents of the specification and must be determined according to the scope of the claims.

Claims

1. A composite dry water explosion suppressant for suppressing organic dust explosions, characterized in that: The composite dry water explosion suppressant includes the following raw materials in parts by weight: 100 parts of deionized water, 10 parts of hydrophobic fumed silica, 0.772 parts of ammonium polyphosphate, 1.487 parts of cobalt nitrate hexahydrate, 1.602 parts of dimethylimidazole, and 200 parts of methanol.

2. The composite dry water explosion suppressant for suppressing organic dust explosion according to claim 1, characterized in that: The proportions of raw materials in the composite dry water explosion suppressant are: 31.86% deionized water, 3.19% hydrophobic fumed silica, 0.25% ammonium polyphosphate, 0.47% cobalt nitrate hexahydrate, 0.51% dimethylimidazole, and 63.72% methanol.

3. The composite dry water explosion suppressant for suppressing organic dust explosion according to claim 1, characterized in that: The particle sizes of hydrophobic fumed silica, ammonium polyphosphate, cobalt nitrate hexahydrate and dimethylimidazole in the raw materials of the composite dry water explosion suppressant are all less than 5 μm.

4. A method for preparing an explosion suppressant, for preparing the composite dry water explosion suppressant according to any one of claims 1 to 3, characterized in that: The specific preparation steps are as follows: S1: In the raw material preparation stage, 1.487 g of cobalt nitrate hexahydrate, 1.602 g of dimethylimidazole, and 0.772 g of ammonium polyphosphate were accurately weighed and set aside for later use; S2: In the solvent preparation stage, 50 ml, 50 ml, and 100 ml of methanol solution were accurately measured in a volume ratio of 1:1:2, and set aside for later use; S3: In a mixing reaction stage, weighed cobalt nitrate hexahydrate, dimethylimidazole, and ammonium polyphosphate are added to 50 ml, 50 ml, and 100 ml of methanol solutions respectively, and stirred for 2 hours to obtain solution A, solution B, and solution C; after the stirring is completed, solution A is first poured into solution B and stirred continuously, and then mixed with solution C, and stirred for another 2 hours to ensure thorough mixing; S4: Filtration and drying stage, the raw materials are filtered and washed to remove impurities; the washed solid is placed in a vacuum drying oven and dried at 60°C for 24 hours; after drying, the solid is taken out and ground to obtain a powder for subsequent use. The obtained solid powder is a ZIF-67 and APP composite material APP-Co-ZIF; S5: In the preparation stage of the composite dry water explosion suppressant, 10 g of hydrophobic fumed silica and 100 ml of deionized water were weighed, 2 g of powder was weighed and poured into the deionized water, and the hydrophobic fumed silica was added, and the mixture was stirred and mixed using a high-speed stirrer to obtain the composite dry water explosion suppressant.

5. The method for preparing an explosion suppressant according to claim 4, characterized in that: The raw materials in step S4 are the raw materials obtained by finally mixing them evenly in S3.

6. The method for preparing an explosion suppressant according to claim 4, characterized in that: The powder in step S5 is the powder obtained by grinding in step S4.

7. The method for preparing an explosion suppressant according to claim 4, characterized in that: The stirring speed in step S5 is 6000 r / min, and the stirring operation lasts for 90 s.

8. The method for preparing an explosion suppressant according to claim 4, characterized in that: Step S5 also includes the step of determining the composite dry water explosion suppressant with the best fluidity under different speeds and times of the high-speed stirrer.

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