Hydrophobic water-containing powder explosion suppressant suitable for gas explosion and preparation method of hydrophobic water-containing powder explosion suppressant

Abstract

The invention provides a hydrophobic water-containing powder explosion suppressant suitable for gas explosion. The hydrophobic water-containing powder explosion suppressant comprises the following components in percentage by mass: 5-15% of hydrophobic nano solid particles, 5-15% of a water-soluble fire extinguishing component, 1-2% of organic gel and the balance of water, and the water-soluble fire extinguishing component is prepared from magnesium hydroxide and zinc borate in a mass ratio of (1: 2)-(2: 1); gel liquid drops formed by the water-soluble fire extinguishing component, the organic gel and water are coated by hydrophobic nano solid particles to form the hydrophobic water-containing powder explosion suppressant with a shell-core structure, the hydrophobic water-containing powder explosion suppressant has a remarkable suppression effect on gas explosion, efficient suppression on gas explosion is achieved, and the preparation method is simple and environmentally friendly.

Description

Technical Field

[0001] The invention relates to the technical field of fire-fighting materials, and in particular to a hydrophobic water-containing powder explosion suppressant suitable for gas explosion and a preparation method thereof. Background Art

[0002] With the rapid development of society, the demand for energy is increasing year by year. Combustible gases mainly exist in daily life and industrial production. Common combustible gases include natural gas, liquefied petroleum gas, coal gas, etc. The main component of natural gas is methane, which is common in the fields of oil and gas chemical industry. Methane, as a high-quality and cheap clean energy, is widely used in people's daily life and production. Whether it is urban gas pipelines or coal mine tunnels, there are a lot of methane gas. Once methane explodes, it will cause serious consequences.

[0003] Gas pipelines are the hardest hit areas for explosions of combustible gases. Once a gas explosion occurs, it will seriously endanger the safety of life and property. If it is not controlled, it may even cause secondary fires, continuous explosions and other secondary expansion accidents, which are extremely harmful.

[0004] Combustible gas pipeline explosion accidents not only cause huge losses to the social economy, but also bring serious threats and challenges to people's lives.

[0005] Gas explosions involve complex physical and chemical reaction processes. At present, the main technology of industrial explosion suppression is to load inert powders or fine water mist and other explosion suppression media into the explosion reaction system to reduce the heat and momentum of the explosion reaction, control the flame growth and shock wave development, and thus reduce the explosion hazard. Liquid explosion suppressants such as fine water mist have strong heat absorption capacity, have significant cooling and suffocating effects on burning materials, and are cheap, easy to obtain, widely available, and environmentally friendly. However, due to their strong fluidity and low boiling point, they are difficult to fully exert their fire extinguishing and explosion suppression performance in large-scale fire and explosion accidents with large fire areas, rapid fire development, and difficulty in extinguishing. Solid explosion suppressants such as ammonium dihydrogen phosphate, sodium hydroxide, ferrocene and other powders generally have the characteristics of physical and chemical composite suppression, and have the advantages of high efficiency and low cost. However, due to their poor cooling properties, they do not have the function of covering and preventing combustion evaporation. After suppressing fire and explosion, they are easy to cause re-ignition, and at the same time, they will cause strong suffocation effects on people and the environment, and their application places are relatively limited.

[0006] Hydrophobic water-containing powder (dry water powder) is a composite material different from traditional powder. It has a core-shell composite structure, with a hydrophobic solid shell enveloping a liquid core. It is a typical solid-liquid synergistic inhibitor. Dry water powder has broad application prospects in the field of fire protection. However, since the dry water powder is liquid inside, it is easy to break when squeezed and easy to evaporate when stored. At the same time, the inhibitory effect mainly depends on the cooling effect of the core liquid, and it cannot have a good inhibitory effect on fire and explosion. The above shortcomings limit the practical application of dry water powder. Summary of the invention

[0007] In order to solve the problems existing in the background technology, the present invention provides a hydrophobic water-containing powder explosion suppressant suitable for gas explosion and a preparation method thereof. The hydrophobic water-containing powder explosion suppressant has a significant inhibitory effect on gas explosion, achieves efficient inhibition of gas explosion, and the preparation method is simple and green and environmentally friendly. The technical solution of the present invention to solve the above technical problems is as follows: In a first aspect, the present invention provides a hydrophobic aqueous powder explosion suppressant suitable for gas explosions, the components of which are calculated by mass percentage as follows: 5% to 15% hydrophobic nano solid particles, 5% to 15% water-soluble fire extinguishing components, 1% to 2% organic gelling agent, and the remainder is water, wherein the water-soluble fire extinguishing component is composed of magnesium hydroxide and zinc borate in a mass ratio of 1:2 to 2:1; gel droplets formed by the water-soluble fire extinguishing component, the organic gelling agent and water are coated by the hydrophobic nano solid particles to form a hydrophobic aqueous powder explosion suppressant with a core-shell structure.

[0008] According to the above scheme, the contact angle of the hydrophobic nano solid particles with water is ≥105°, and the particles are selected from one or more of hydrophobic fumed silica, graphite, titanium dioxide, boron nitride, zinc stearate, calcium fluoride, polytetrafluoroethylene, magnesium silicate, aluminum silicate, aluminum oxide, zinc oxide, polydimethylsiloxane, polystyrene, hydrophobic methylcellulose, carbon nitride trifluoride, caged silsesquioxane, decabromodiphenylethane, and 1,2-bis(2,3,4,5,6-pentabromophenyl)ethane.

[0009] Furthermore, the hydrophobic nano solid particles are hydrophobic fumed silica, with an average particle size of 5-10 nm, a silica content of ≥99.8 wt %, and a contact angle with water of ≥110°.

[0010] According to the above scheme, the organic gel is selected from one or more of sodium carboxymethyl cellulose, gelatin, agar, sodium succinate, pectin, polyacrylamide, polyvinyl alcohol, hydroxypropyl methylcellulose, chitosan, polymerized urethane, polyethyleneimine, polymerized silicone, xylan, and poly(ethylene glycol) acrylate.

[0011] Preferably, the organic gelling agent is sodium carboxymethyl cellulose.

[0012] The colloidal particles or polymers in the organic gel can interact with each other to form a spatial network structure, thereby enhancing the structural strength of the powder. At the same time, it can also prevent the evaporation of the liquid from the core to a certain extent, thereby extending the life of the powder.

[0013] According to the above scheme, the mass ratio of magnesium hydroxide to zinc borate is 1:1.5~1.5:1.

[0014] According to the above scheme, a preferred scheme in the present invention is: 5-10wt% hydrophobic fumed silica, 10-15wt% water-soluble fire extinguishing component, 1-3wt% sodium carboxymethyl cellulose, and the balance is water.

[0015] In a second aspect, the present invention provides a method for preparing the hydrophobic water-containing powder explosion suppressant suitable for gas explosion, comprising the following steps: S1. Weigh the raw material components in proportion and set aside; S2. Mix water, a water-soluble fire extinguishing component and an organic gelling agent, stir thoroughly, add hydrophobic nano solid particles, and stir for 2 to 5 minutes at a stirring rate of 4000 to 8000 rpm to obtain the hydrophobic water-containing powder explosion suppressant.

[0016] According to the above scheme, the mixing method in step S2 is: adding the water-soluble fire extinguishing component into water and stirring until it is completely dissolved, and then adding the organic gelling agent and stirring until the solution is completely converted into a gel liquid.

[0017] According to the above scheme, the stirring rate in step S2 is 5000-6500 rpm, and the stirring time is 3-4 minutes.

[0018] Stirring rate and time have a significant effect on the formation of hydrophobic water-containing powders. Stirring rate that is too low or time that is too short will result in insufficient fusion of the components and low yield; stirring rate that is too high or time that is too long will cause the formed particles to be re-crushed to form a paste-like material.

[0019] The present invention converts the core material from water to gel by reacting an organic gelling agent with water, and then the core material is wrapped by hydrophobic nano solid particles to form a hydrophobic water-containing powder explosion suppressant with a core-shell structure. The core material is converted from water to gel, which improves its water retention and significantly prolongs the storage time of the hydrophobic water-containing powder explosion suppressant. On the other hand, it increases its pressure resistance and stability, ensuring that the structure does not break under high spraying pressure. At the same time, the internal water can evaporate quickly at high temperature without affecting its cooling and chemical inhibition.

[0020] In view of the characteristics of gas explosions, magnesium hydroxide and zinc borate are selected as water-soluble fire extinguishing components. Magnesium hydroxide decomposes when heated to absorb heat from the surface of the burning material to play a flame retardant role, and releases a large amount of water to dilute the oxygen on the surface of the burning material. The active magnesium oxide generated by the decomposition adheres to the surface of the combustible material and further prevents the combustion. Zinc borate generates zinc oxide when heated, which can combine with key free radicals in the explosion fire scene and consume the free radicals in the reaction system, thereby interrupting the explosion chain reaction. The two work synergistically to achieve efficient suppression of gas explosions.

[0021] The beneficial effects of the present invention are: 1. The present invention converts the internal solution into a gel liquid by reacting an organic gelling agent with a water-soluble fire extinguishing component and water, thereby significantly improving the compressive resistance and water retention of a hydrophobic water-containing powder; forming a solid-liquid two-phase synergistic explosion suppressant system, and combining magnesium hydroxide and zinc borate, based on the synergistic effect of each component in the system, exerting physical and chemical synergistic inhibition, so that the hydrophobic water-containing powder explosion suppressant has a significant inhibitory effect on gas explosion, thereby achieving efficient inhibition of gas explosion; 2. The components used in the hydrophobic water-containing powder explosion suppressant prepared by the present invention have no significant harm to human body and environment, and the raw material resources are abundant, the cost is low, the production process is simple, and it is green and environmentally friendly. DETAILED DESCRIPTION

[0022] The principles and features of the present invention are described below in conjunction with specific embodiments. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0023] Example 1 The present embodiment provides a hydrophobic water-containing powder explosion suppressant suitable for gas explosions, wherein the weight ratio of the raw materials and components is as follows: the mass ratio of hydrophobic fumed silica: water: magnesium hydroxide: zinc borate: sodium carboxymethyl cellulose is 9:100:7.5:7.5:1.5.

[0024] The specific preparation method is as follows: 1. Add magnesium hydroxide and zinc borate into deionized water respectively; 2. Add sodium carboxymethyl cellulose to the solution and stir the solution evenly to make it have a certain viscosity; 3. Immediately add hydrophobic fumed silica and stir at a stirring rate of 6500 rpm for 3 minutes to obtain a hydrophobic aqueous powder explosion suppressant containing magnesium hydroxide and zinc borate gel.

[0025] Example 2 The present embodiment provides a hydrophobic water-containing powder explosion suppressant suitable for gas explosions. The raw material components and mass percentages thereof are as follows: 10% hydrophobic fumed silica, 7.5% magnesium hydroxide, 7.5% zinc borate, 1.5% sodium carboxymethyl cellulose, and the balance is water. The preparation method is the same as that of Example 1.

[0026] Example 3 The present embodiment provides a hydrophobic water-containing powder explosion suppressant suitable for gas explosions. The raw material components and mass percentages thereof are as follows: 15% hydrophobic fumed silica, 6% magnesium hydroxide, 4% zinc borate, 1.2% sodium carboxymethyl cellulose, and the balance is water. The preparation method is the same as that of Example 1.

[0027] Example 4 The present embodiment provides a hydrophobic water-containing powder explosion suppressant suitable for gas explosions, the raw material composition and mass percentage of which are as follows: 5% hydrophobic fumed silica, 3% magnesium hydroxide, 3% zinc borate, 2% sodium carboxymethyl cellulose, and the balance is water. The preparation method is the same as that of Example 1.

[0028] Comparative Example 1 This comparative example provides a common hydrophobic water-containing powder explosion suppressant, and the preparation method is as follows: hydrophobic fumed silica and deionized water are added into a variable frequency disperser at a mass ratio of 9:100, the stirring rate is set to 5000 rpm, and stirring is performed for 2 minutes.

[0029] Comparative Example 2 Compared with Example 1, the preparation process is the same, and the components are prepared in the following weight proportion: hydrophobic fumed silica: water: magnesium hydroxide: zinc borate: sodium carboxymethyl cellulose is 9:100:7.5:7.5:1, wherein the mass percentage of sodium carboxymethyl cellulose is 0.8%.

[0030] Comparative Example 3 Compared with Example 1, the preparation process is the same, and the components are prepared in the following proportions: hydrophobic fumed silica: water: magnesium hydroxide: zinc borate: sodium carboxymethyl cellulose is 9:100:7.5:7.5:3, wherein the mass percentage of sodium carboxymethyl cellulose is 2.3%.

[0031] Comparative Example 4 Compared with Example 1, zinc borate is not contained, the preparation process is the same, and the components are prepared in the following proportions: hydrophobic fumed silica: water: magnesium hydroxide: sodium carboxymethyl cellulose is 9:100:15:1.5.

[0032] Comparative Example 5 Compared with Example 1, magnesium hydroxide is not contained, the preparation process is the same, and the components are prepared in the following proportions: hydrophobic fumed silica: water: zinc borate: sodium carboxymethyl cellulose is 9:100:15:1.5.

[0033] The powders prepared in the above examples and comparative examples 1-5 are shown in Table 1 below.

[0034] Table 1 Preparation results of examples and comparative examples

[0035] In Comparative Example 3, due to the excessively high content of the organic gelling agent, the prepared finished product was in a mousse-like state rather than a powdery state.

[0036] The hydrophobic aqueous powder explosion suppressant prepared in Example 1, the ordinary hydrophobic aqueous powder prepared in Comparative Example 1, and the hydrophobic aqueous powder explosion suppressants prepared in Comparative Examples 2 to 5 were tested for stability, water retention, fluidity and explosion suppression performance. The test methods and results are as follows.

[0037] 1. Stability test The stability of the hydrophobic water-containing powder explosion suppressants prepared in Example 1 and Comparative Examples 1 and 2 was tested according to GB4066-2017 standard. The test steps are as follows: 1) Use a measuring cylinder to measure 40 mL of hydrophobic water-containing powder explosion suppressant and add it to the angle rotor; 2) Place in a centrifuge and centrifuge at 6000 rpm for 5 minutes; 3) After standing for 3 minutes, measure the volume of the supernatant.

[0038] The centrifuge liquid of the products prepared in each embodiment and comparative example is shown in Table 2.

[0039] Table 2

[0040] As can be seen from Table 2, the compressive strength of the hydrophobic aqueous powder prepared in Example 1 is significantly higher than that of Comparative Example 1 and Comparative Example 2. In Comparative Example 2, due to the addition of too little sodium carboxymethyl cellulose, the stability of the hydrophobic aqueous powder is slightly improved, and the centrifuge liquid is significantly higher than that of Example 1, indicating that the transformation of the core material from water to gel enhances the structural strength of the hydrophobic powder explosion suppressant, and enhances its compressive strength and stability.

[0041] 2. Water retention test The water retention of the hydrophobic water-containing powder explosion suppressant prepared in Example 1 and Comparative Example 1 was tested according to GB4066-2017 standard. The test steps are as follows: 1) Place 20 g of the powder of Comparative Example 1 and the powder of Example 1 in two glass dishes with a diameter of 9 cm respectively; 2) Place the culture dish in a drying oven and set the temperature to 25°C; 3) Measure the remaining mass daily and calculate the mass loss.

[0042] The powder of Comparative Example 1 lost 82.4% of its mass after 30 days, the core liquid was almost completely evaporated, and the remainder was hydrophobic fumed silica.

[0043] The mass loss of the hydrophobic water-containing powder explosion suppressant in Example 1 was 68.4% after 30 days, and the water retention was significantly improved compared with that in Comparative Example 1, indicating that the transformation of the core material from water to gel enhanced the structural strength of the hydrophobic water-containing powder explosion suppressant, increased its water retention, and significantly prolonged the storage time of the hydrophobic water-containing powder explosion suppressant.

[0044] 3. Particle size distribution The mechanical sieving method was used to measure the particle size distribution of the powder. The powder was placed in a standard sieve with different mesh sizes and vibrated for 10 minutes, and the mass percentage of each layer was collected and calculated. The results show that the particle size of Comparative Example 1 is mainly concentrated in 100~200 μm, while the particle size of Example 1 is mainly distributed in 50~100 μm. The overall particle size of the powder in Example 1 is significantly smaller than the particle size of the powder in Comparative Example 1. The smaller particle size increases the specific surface area of ​​the dry water powder, which can better capture free radicals in the fire scene. Most importantly, the powder with a smaller particle size can have a faster decomposition rate in the fire scene.

[0045] 4. Liquidity test The fluidity of the hydrophobic water-containing powders prepared in Example 1 and Comparative Example 1 was measured by the angle of repose method. 50 ml of powder was placed in a funnel, fully dispersed, and then discharged from the bottom. The discharge time and the radius and height of the powder pile were recorded, and the angle of repose of the powder was calculated according to the formula θ=arctan(h / r). The flow rate was calculated based on the discharge time to evaluate the fluidity of the powder.

[0046] The results show that the outflow rate of the hydrophobic aqueous powder explosion suppressant in Example 1 is 2.32 mL / s, and the outflow rate of the aqueous powder in Comparative Example 1 is 1.70 mL / s. The angle of repose of the hydrophobic aqueous powder explosion suppressant in Example 1 is 28.81°, and the angle of repose of the aqueous powder in Comparative Example 1 is 34.41°. Therefore, the hydrophobic aqueous powder explosion suppressant prepared in Example 1 has a higher outflow rate and a smaller angle of repose, and its fluidity is significantly better than that of Comparative Example 1.

[0047] 5. Explosion suppression performance test In order to evaluate the inhibitory effect of the hydrophobic aqueous powder explosion suppressant on methane / air explosion, the following experiments were conducted on the aqueous powder explosion suppressants prepared in Example 1, Comparative Example 1, Comparative Example 4 and Comparative Example 5: The explosion suppression device includes a visual gas explosion system, a gas distribution system, a powder injection system, an ignition system, a high-frequency data acquisition system, a high-speed camera system and a synchronous control system. The visual gas explosion system consists of three pipes (1m × 0.11m × 0.11m), which are connected by flange bolts, and observation windows with a size of 0.3m × 0.1m are installed symmetrically on both sides. The gas distribution system injects methane-air premixed gas with a methane content of 9.5Vol% into the pipeline. The powder injection system consists of a high-pressure gas storage tank, a solenoid valve and a powder storage tank, which are located at the midpoint of the pipeline. After the powder is evenly injected into the pipeline, the ignition system uses a high-voltage igniter for discharge ignition. The data acquisition system mainly includes a data acquisition instrument, a thermocouple and a pressure sensor. The thermocouple is arranged 0.5 meters from the end of the pipeline to record the flame temperature after explosion suppression. The pressure sensor is placed 0.5 meters from the end of the pipeline to record the pressure changes in the confined space. High-speed photography captures images at 5,000 frames per second, ensuring that the flame morphology is captured clearly.

[0048] After installing and debugging the experimental system, a gas distributor was used to configure a methane / air premixed gas with a methane content of 9.5 vol%. The premixed gas was filled into the pipeline with a volume 4 times the volume of the pipeline by exhausting air to ensure that the inside of the pipeline was uniformly premixed with methane / air gas. At the same time, compressed air was filled into the gas tank to make the spraying pressure reach 0.2 MPa. After the inflation was completed, the premixed gas in the pipeline was left to stand for 2 minutes to reduce the impact of turbulence on the experimental results during the inflation process. After pressing the ignition switch, the data acquisition instrument and the high-speed camera began to collect temperature, pressure and explosion flame images. At the same time, the solenoid valve in the dry water powder injection system was opened, and the high-pressure air carried the dry water powder into the pipeline and formed a uniform dust cloud. After 0.2s, the high-voltage ignition electrode continued to generate electric sparks for 0.2s.

[0049] The water-containing powder explosion suppressant in Example 1 was subjected to three simulation tests, namely Test 1, Test 2 and Test 3, with the addition amounts being 15 g, 12 g and 12 g respectively. The results are shown in Table 3.

[0050] Table 3

[0051] ① From the flame observed through the observation window, when no inhibitor is added, the flame propagates continuously, filling the entire observation window. Turbulence occurs when the flame front propagates along the pipeline, causing the flame speed at the upper and lower ends of the pipeline to accelerate, and the flame front undergoes wrinkling and deformation and a depression in the center, forming a tulip-shaped flame. Subsequently, the tulip-shaped flame disappears due to the influence of the reflected wave in the closed pipeline. Except for the bright yellow preheating area at the front of the flame, almost the entire flame image is overexposed and appears bright white.

[0052] When the powder of comparative example 1 is added, the brightness of the flame is significantly reduced, but the time for the flame to reach the bottom of the observation window is not significantly delayed. When the addition amount is 12g, the brightness of the flame is significantly reduced, indicating that the powder in comparative example 1 has a certain inhibitory effect on the explosion, but the flame still spreads completely to the bottom of the observation window, indicating that the explosion suppression effect of the powder in comparative example 1 is limited. When 12g of the powder in comparative example 4 is added, the flame front becomes blurred, indicating that the free radicals produced by the methane explosion are adsorbed by magnesium hydroxide, and magnesium hydroxide absorbs heat and produces water, which reduces the brightness of the flame and inhibits the spread of the flame, but the flame still spreads completely to the bottom of the observation window, indicating that the explosion suppression effect of the powder in comparative example 4 is limited. When 12g of the powder of comparative example 5 is added, due to the presence of boron, the flame presents a little green. Although the flame structure has been significantly destroyed, the flame cannot be completely suppressed and can still pass through the observation window, indicating that comparative example 5 has a limited explosion suppression effect on methane. When the hydrophobic water-containing powder explosion suppressant of Example 1 is added, the flame becomes significantly darker, the structure is significantly destroyed, and the flame is discontinuous during the propagation process. When 12 g or more of the hydrophobic aqueous powder explosion suppressant in Example 1 was added, the concentration of the hydrophobic aqueous powder explosion suppressant in the pipeline completely suppressed the explosion, and no flame propagation was observed in the observation window.

[0053] ② From the temperature point of view, when 12g of the hydrophobic aqueous powder explosion suppressant of Comparative Example 1 was added, the temperature was only reduced by 5% compared with not adding the inhibitor. When 12g of the explosion suppressant in Comparative Examples 4 and 5 was added, the temperature was reduced by 47.9% and 30.1% respectively, but still reached 849°C and 1139.9°C, and the explosion was not effectively suppressed. The flame continued to spread backward. When 12g of the hydrophobic aqueous powder explosion suppressant in Example 1 was added, the peak temperature was reduced by about 96.9% and 97.5%. When 15g of the powder was added, the peak temperature was reduced by about 97.8%, and the temperature reached 50.3°C, 40.7°C and 36.4°C, indicating that the explosion was effectively suppressed after the hydrophobic aqueous powder explosion suppressant in Example 1 was added, and the flame was prevented from spreading backward.

[0054] ③ From the explosion pressure point of view, compared with not adding any explosion suppressant, after adding the hydrophobic aqueous powder explosion suppressant of Comparative Examples 1, 4 and 5, the explosion pressure peak value was reduced by 43.52%, 68.67% and 54%, while after adding the three batches of hydrophobic aqueous powder explosion suppressant in Example 1, the pressure peak value was reduced by 69.44%, 68.67% and 68.77%, which was significantly reduced compared with Comparative Examples 1 and 5.

[0055] Based on the observed flame conditions, pressure at the end of the pipeline and temperature data, the hydrophobic hydrated powder in Comparative Examples 1, 4 and 5 can inhibit the spread of flames and reduce the pressure and temperature generated by the explosion, but its inhibitory effect is effective and cannot completely inhibit the explosion. The hydrophobic hydrated powder explosion suppressant of Example 1 of the present invention can show a stronger explosion suppression effect due to the synergistic effect of magnesium hydroxide and zinc borate, and the explosion is completely suppressed, and the flame is prevented from spreading backwards, effectively reducing the temperature and pressure.

[0056] The hydrophobic water-containing powder prepared in Example 2-4 was also tested for explosion suppression performance using the above system. The observed flame conditions and the temperature and pressure data at the end of the pipeline obtained from the test showed that the hydrophobic water-containing powder prepared in Example 2-4 could also completely suppress explosion.

[0057] The hydrophobic water-containing powder explosion suppressant prepared by the invention has physical and chemical suppression on gas explosion.

[0058] Physical inhibition is manifested in the following aspects: first, the core material of the powder is pyrolyzed by heat, in which magnesium hydroxide decomposes into MgO, zinc borate dehydrates and pyrolyzes into non-flammable B2O3 and ZnO, and water molecules evaporate. These three processes can absorb part of the heat generated by the combustion reaction, thereby reducing the reaction temperature; second, the water vapor generated by pyrolysis dilutes the concentration of combustibles and oxygen at the same time. According to the chemical reaction collision theory, the premise of methane explosion reaction is the effective collision between CH4 and O2. The dilution effect of water vapor reduces the collision probability of methane molecules and oxygen, making the explosion reaction more difficult to occur. Part of the zinc in zinc borate enters the gas phase in the form of ZnO or Zn(OH)2 and occupies a large amount of space in the combustion zone and the unburned zone, reducing the concentration of combustibles, thereby reducing the combustion reaction rate and inhibiting the explosion; third, the silica in the powder shell, the MgO generated by the decomposition of magnesium hydroxide, and the B2O3 generated by zinc borate can effectively isolate oxygen and heat, prevent further pyrolysis, and weaken the heat transfer of the combustion products in the reaction zone to the unburned zone, thereby reducing the intensity of methane explosion.

[0059] Chemical inhibition is mainly manifested in blocking chain reactions by capturing free radicals, such as high-energy free radicals in the reaction zone such as O·, H·, and OH·. When these free radicals collide with Mg(OH)2 particles, they will be adsorbed, accelerating the consumption of free radicals, greatly reducing the probability of collision between free radicals, resulting in the interruption of some chain reactions, thereby further reducing the explosion intensity; the combination of water molecules and free radicals O·, H·, and OH· hinders the development of the methane explosion chain and plays a role in inhibiting methane explosions; and ZnO generated by the heat of zinc borate continuously captures free radicals H· and OH· during the combustion process, thereby preventing the spread of flames and further reducing the density of the flame in the combustion zone and the combustion reaction rate; in addition, due to the high specific surface area of ​​the silica shell, it has a significant adsorption effect on free radicals near the combustion reaction zone, reducing the free radical concentration, thereby reducing the combustion reaction rate and reducing the intensity of the gas explosion.

[0060] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A hydrophobic water-containing powder explosion suppressant suitable for gas explosion, characterized in that: The components thereof are as follows by mass percentage: 5% to 15% of hydrophobic nano solid particles, 5% to 15% of water-soluble fire extinguishing components, 1% to 2% of organic gelling agent, and the balance is water, wherein the water-soluble fire extinguishing components are composed of magnesium hydroxide and zinc borate in a mass ratio of 1:2 to 2:1; The hydrophobic water-containing powder explosion suppressant has a core-shell structure, in which gel droplets formed by water-soluble fire extinguishing components, organic gelling agent and water are coated by hydrophobic nano solid particles.

2. The hydrophobic water-containing powder explosion suppressant suitable for gas explosion according to claim 1, characterized in that: The contact angle of the hydrophobic nano solid particles with water is ≥105°, and the particles are selected from one or more of hydrophobic fumed silica, graphite, titanium dioxide, boron nitride, zinc stearate, calcium fluoride, polytetrafluoroethylene, magnesium silicate, aluminum silicate, aluminum oxide, zinc oxide, polydimethylsiloxane, polystyrene, hydrophobic methylcellulose, carbon nitride trifluoride, caged silsesquioxane, decabromodiphenylethane, and 1,2-bis(2,3,4,5,6-pentabromophenyl)ethane.

3. The hydrophobic water-containing powder explosion suppressant suitable for gas explosion according to claim 2, characterized in that: The hydrophobic nano solid particles are hydrophobic fumed silica, with an average particle size of 5-10 nm, a silica content of ≥99.8wt%, and a contact angle with water of ≥110°.

4. The hydrophobic water-containing powder explosion suppressant suitable for gas explosion according to claim 1, characterized in that: The organic gel is selected from one or more of sodium carboxymethyl cellulose, gelatin, agar, sodium succinate, pectin, polyacrylamide, polyvinyl alcohol, hydroxypropyl methylcellulose, chitosan, polymerized urethane, polyethyleneimine, polymerized siloxane, xylan, and poly(ethylene glycol) acrylate.

5. The hydrophobic water-containing powder explosion suppressant suitable for gas explosion according to claim 4, characterized in that: The organic gelling agent is sodium carboxymethyl cellulose.

6. The hydrophobic water-containing powder explosion suppressant suitable for gas explosion according to claim 1, characterized in that: The mass ratio of magnesium hydroxide to zinc borate is 1:1.5~1.5:

1.

7. The hydrophobic water-containing powder explosion suppressant suitable for gas explosion according to any one of claims 1 to 6, characterized in that: The invention is composed of the following components in percentage by weight: 5-10 wt % of hydrophobic fumed silica, 10-15 wt % of a water-soluble fire extinguishing component, 1-3 wt % of sodium carboxymethyl cellulose, and the balance being water.

8. The method for preparing a hydrophobic water-containing powder explosion suppressant suitable for gas explosion according to any one of claims 1 to 7, characterized in that: The steps include: S1. Weigh the raw material components in proportion and set aside; S2. Mix water, a water-soluble fire extinguishing component and an organic gelling agent, stir thoroughly, add hydrophobic nano solid particles, and stir for 2 to 5 minutes at a stirring rate of 4000 to 8000 rpm to obtain the hydrophobic water-containing powder explosion suppressant.

9. The preparation method according to claim 8, characterized in that: The mixing method in step S2 is: adding the water-soluble fire extinguishing component into water and stirring until it is completely dissolved, and then adding the organic gelling agent and stirring until the solution is completely converted into a gel liquid.

10. The preparation method according to claim 8, characterized in that: The stirring rate in step S2 is 5000-6500 rpm, and the stirring time is 3-4 minutes.

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