173 results on '"Explosion suppression"'
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2. Applicability of HFC-227ea/CO2 for battery energy storage systems safety: Insights from explosion suppression experiments and kinetic analysis
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Yu, Tianmin, Wang, Yan, Chen, Jie, Ji, Wentao, Gao, Baobin, Zhu, Jiateng, and Qin, Shengze
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- 2025
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3. Experimental and numerical investigation of premixed hydrogen-air explosion suppression by heptafluoropropane and carbon dioxide mixtures
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Nie, Baisheng, Zhang, Mengying, and Chang, Li
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- 2024
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4. Zinc phytate@chitosan bio-powder renders explosion suppression of titanium powder involved in industrial processes
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Yu, Kainan, Wang, YaChao, Zhang, Shuqi, and Zhao, JiangPing
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- 2024
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5. Study on the inhibition of hydrogen explosion using gas-solid two-phase inhibitors
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Yu, Yanan, Qu, Haowen, Ping, Ping, and Liu, Yi
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- 2024
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6. Experimental studies on the explosion characteristics of LDPE dust under the action of wire mesh
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Yang, Kai, Zhai, Manru, Chen, Jihe, Li, Jiaqi, Zhu, Tingrui, Huang, Shuaishuai, Huang, Ruofan, Lv, Pengfei, and Shen, Jing
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- 2025
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7. Determination the suppression effect and mechanism of C2HF5 on premixed ethylene-air explosion through experiment and simulation
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Su, Mingqing, Chen, Sining, Jiang, Bingyou, Duo, Yingquan, Li, Jingjing, Ji, Ben, Kong, Xiangbei, and Wei, Lijun
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- 2025
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8. Attenuation characteristics of hydrogen-air deflagration wave passing through inert gas section under non-premixed conditions
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Liang, He, Yan, Xingqing, Hu, Yanwei, Shi, Enhua, Qi, Chang, Ding, Jianfei, Zhang, Lianzhuo, Dang, Qian, Lv, Xianshu, and Yu, Jianliang
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- 2025
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9. Phase change materials as hydrogen explosion suppressants: An experimental and kinetic investigation
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Wang, Tao, Dong, Zhe, Yang, Peng, Sheng, Yuhuai, Yang, Zhe, Tian, Xiaoyue, Meng, Fan, and Luo, Zhenmin
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- 2024
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10. A modified phosphorus-based inhibitor for dry water inhibitor and its chemical mechanisms in preventing benzoyl peroxide explosion
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Dong, Zhangqiang, Gao, Wei, Bai, Qinglun, Jin, Songling, Ma, Qianyu, Wang, Ke, Xue, Chenlu, and Jiang, Haipeng
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- 2024
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11. Experimental investigation of collaboration effect of HFC-227ea/CO2 suppression of hydrogen enriched compressed natural gas explosion
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Li, Manhou, Ji, Shijie, Yao, Yingkang, Xie, Quanmin, and Wang, Yixian
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- 2024
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12. Basic theory of dust explosion of energetic materials: A review
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Yin, Mengli, Wang, Chunyan, Guo, Haoyang, Shi, Yuhuai, Shi, Shengnan, Wang, Wenhui, and Cao, Xiong
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- 2024
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13. Effect of Ultrafine Water Mist with K 2 CO 3 Additives on the Combustion and Explosion Characteristics of Methane/Hydrogen/Air Premixed Flames.
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Zhang, Haoliang, Mi, Hongfu, Shao, Peng, Luo, Nan, Liao, Kaixuan, Wang, Wenhe, Duan, Yulong, and Niu, Yihui
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HEAT release rates ,FLAME stability ,CHEMICAL kinetics ,FREE radicals ,NATURAL gas ,FLAME ,HYDROGEN flames - Abstract
To ensure the safe utilization of hydrogen-enriched natural gas (HENG), it is essential to explore effective explosion suppressants to prevent and mitigate potential explosions. This study experimentally investigates the impact of ultrafine water mist containing K
2 CO3 additives on the explosion characteristics of methane/hydrogen/air premixed combustion. The influence of varying K2 CO3 concentrations on pressure rise rates and flame propagation was analyzed across different hydrogen blending ratios. The results demonstrate that the addition of K2 CO3 to ultrafine water mist significantly enhances its suppression effects. The peak overpressure decreased by 41.60%, 56.15%, 64.94%, and 72.98%, the flame speed decreased by 30.66%, 70.56%, 46.72%, and 65.65%, and the flame propagation time was prolonged by 25%, 20.83%, 22.92%, and 18.75%, respectively, for different hydrogen blending ratios, showing a similar trend. However, the suppression effectiveness diminishes under high hydrogen blending ratios and low K2 CO3 concentrations. Further analysis using thermogravimetric infrared spectroscopy and chemical kinetics simulations revealed that the heat release rate and the generation rate of active free radicals significantly decrease after the addition of K2 CO3 to the ultrafine water mist. The recombination cycle of KOH → K → KOH, formed by reactions (R211: K + OH + M = KOH + M) and (R259: H + KOH = K + H2 O), continuously combines active free radicals (·O, ·OH) into stable product molecules, such as H2 O. However, at low K2 CO3 concentrations, reaction R211, which suppresses laminar combustion sensitivity and consumes a larger quantity of active free radicals, does not dominate, leading to a reduced suppression effect of K2 CO3 ultrafine water mist. Several factors during the reaction process also adversely affect the performance of K2 CO3 -containing ultrafine water mist. These factors include the premature onset of laminar flame instability at low K2 CO3 concentrations, the increased flame-front propagation speed due to the addition of hydrogen to methane, which shortens the residence time of K2 CO3 in the reaction zone, and the turbulence caused by unvaporized droplets. [ABSTRACT FROM AUTHOR]- Published
- 2024
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14. So, you cannot vent: A deep dive into other explosion protection methods.
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Murphy, Michelle
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OXIDIZING agents ,DUST ,EXPLOSIONS ,DUST explosions ,HAZARDS - Abstract
Current NFPA standards for managing combustible dust hazards require equipment with an explosion hazard to be protected from the effects of deflagration. These protections include deflagration venting in accordance with NFPA 68, Standard on Explosion Protection by Deflagration Venting, 2023 Edition, or oxidant concentration reduction, combustible concentration reduction, deflagration suppression, or deflagration pressure containment, via NFPA 69, Standard on Explosion Protection Systems, 2024 Edition. It makes sense to choose the simplest and most cost‐effective option based on the inherent design and risk of the operation. Implementation of any one of these protection methods requires an understanding of the method and all the associated requirements. While the basic methods are fairly straightforward, the associated requirements are often less understood. In this paper, the author will introduce the basic methods and take a deep dive into the associated requirements of each method of protection. Based on the author's experience in evaluating protection systems, common misunderstandings will be highlighted, for example, the margin of safety to apply and the operational limits required to be developed and documented for oxidant concentration reduction systems. [ABSTRACT FROM AUTHOR]
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- 2024
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15. Research progress of the combustion characteristics of dust/combustible gas hybrids
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Jialin Li, Fen Li, Zhao Xu, Jianmin Yang, and Jianjun Li
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Hybrid mixture ,Explosion regime ,Flame characteristic ,Safety parameter ,Explosion suppression ,Explosives and pyrotechnics ,TP267.5-301 - Abstract
Due to the high dispersion of solid powder, it is very easy to form a powder/gas hybrid system, which greatly increases the probability and severity of explosion accidents. The researchers both domestically and internationally have conducted extensive research on the hybrids explosion systems. This paper reviews the combustion characteristics, explosion mechanisms, and explosion prevention experiments of hybrids. Current research results on explosion prevention technology are organized, and the current challenges in experimental studies of hybrids explosions are summarized, providing references for future experimental studies.
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- 2024
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16. Study on the characteristics and mechanism of inert powder inhibition of gas/coal dust compound explosion
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Wentao JI, Guotao ZHANG, Shuaishuai YANG, Zihui XU, Wenzhe MAO, and Yan WANG
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gas ,coal dust ,composite explosion ,sodium bicarbonate ,calcium carbonate ,explosion suppression ,Mining engineering. Metallurgy ,TN1-997 - Abstract
Gas/coal dust composite explosion is a complex process that combines homogeneous and heterogeneous combustion. The combustion main control mechanism changes dynamically and the explosion mechanism is more complex, resulting in higher explosion sensitivity and explosion intensity compared to single-phase gas or coal dust explosion, which seriously restricts the safe production of coal mines. In order to prevent and control the gas/coal dust composite explosion disaster, two inert powders, sodium bicarbonate and calcium carbonate, are selected to conduct experiments on inert powder suppression of gas/coal dust composite explosions in a 20 L spherical explosion device. Based on the different concentration ratios of gas and coal dust, the inhibition effect of two inert powders on the maximum explosion pressure and the maximum explosion pressure rise rate of the gas/coal dust composite system are analyzed and compared, as well as the differences and connections between the inhibition effect of the two inert powders. And the inhibition efficiency and mechanism of the two inert powders on gas/coal dust composite explosions are reflected comprehensively. The research results indicate that sodium bicarbonate and calcium carbonate have an inhibitory effect on the explosion of gas/coal dust composite systems with different concentration ratios. Sodium bicarbonate can not only suppress the explosion of gas/coal dust composite by physical suppression methods such as decomposing heat absorption, delaying coal dust pyrolysis, and reducing coal dust decomposition rate, but also by chemical suppression methods that consume key free radicals in the explosion reaction, however, calcium carbonate can only suppress explosions through physical heat absorption, so the inhibitory effect of sodium bicarbonate on the explosion of gas/coal dust composite system is better than that of calcium carbonate. Specifically, sodium bicarbonate can completely suppress all working conditions, while calcium carbonate can only completely suppress the gas/coal dust composite working conditions when the gas concentration is below 8%. In addition, the suppression efficiency of two inert powders on the explosion pressure of the gas/coal dust composite system first increases and then decreases with the increase of gas concentration in the system. The suppression efficiency is highest when the gas concentration is 6% and the coal dust concentration is 100 g/m3; The suppression efficiency of the explosion pressure rise rate of the gas/coal dust composite system gradually increases with the increase of gas concentration in the system, and the suppression efficiency is highest for pure gas explosions with a concentration of 10%.
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- 2024
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17. 惰性粉体抑制瓦斯/煤尘复合爆炸特性及机理研究.
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纪文涛, 张国涛, 杨帅帅, 徐子晖, 毛文哲, and 王燕
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COAL dust ,DUST explosions ,GAS explosions ,FREE radical reactions ,HEAT radiation & absorption ,CALCIUM carbonate - Abstract
Copyright of Coal Science & Technology (0253-2336) is the property of Coal Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2024
- Full Text
- View/download PDF
18. Study on suppression of ABC powder and potassium bicarbonate-zeolite composite powder on explosion of hydrogen enriched compressed natural gas.
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Li, Manhou, Ji, Shijie, Li, Quan, Yao, Yingkang, and Xie, Quanmin
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NATURAL gas pipelines , *PACLOBUTRAZOL , *POWDERS , *FLAME , *POTASSIUM - Abstract
For large quantities of hydrogen transportation, it is a potential solution for mixing a certain proportion of hydrogen into natural gas pipeline network. In is imperative to seek efficient explosion suppressants of hydrogen enriched compressed natural gas (HCNG). In current work, a 125 L cubic explosion container was developed to conduct the suppression experiments on 20% and 50% HCNG explosion using inhibitory solids of 0.04–0.32 g/L ABC powder and 0.04–0.16 g/L potassium bicarbonate-zeolite (PBZ) composite powder. The thermodynamic and particle size properties of ABC powder and PBZ composite powder were analyzed to interpret these suppression effects. The pressure history curve and explosion flame appearance were recorded. The flame exhibited a deformation and wrinkles characteristic when the solid suppressants were employed. The optimal concentrations of ABC powder and PBZ composite powder suppression were attained. The physical and chemical mechanisms of explosion mitigation with ABC powder or PBZ composite powder were fully revealed. The single inhibitory powder of ABC powder or PBZ composite powder could not fully restrict the HCNG explosion. The current results possessed some practical guidance for restriction of HCNG explosion in industrial confined spaces. • Powder suppressions on 20% and 50% HCNG explosion are conducted. • Flame shows a deformation and wrinkles shape under inhibitory powders. • The inhibitory effect of PBZ composite powder is than that of ABC powder. • Optimal concentrations of ABC powder and PBZ composite powder are attained. [ABSTRACT FROM AUTHOR]
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- 2024
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19. Suppressive effects of potassium salt modified dry water material on hydrogen/methane mixture explosion.
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Cai, Chongchong, Su, Yang, Wang, Yan, and Ji, Wentao
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POTASSIUM salts , *METHANE as fuel , *HYDROGEN as fuel , *PARTICLE swarm optimization , *EXPLOSIONS , *METHANE , *FUEL cells , *EXPLOSIVES - Abstract
As a new type of energy, hydrogen-enriched methane mixed fuel has a high risk of deflagration in the application process. In order to better understand the deflagration and inhibition characteristics of hydrogen-enriched methane fuel, the effect of potassium salt modified dry water material (DW) on the deflagration characteristics of hydrogen-enriched methane fuel was studied by 20 L spherical explosive apparatus, combined with pyrolysis characteristics and kinetic model. The results show that when the addition of different modifier concentrations, it can be divided into three types: small curvature, medium curvature and large curvature according to the change of pressure rising rate. With the increase of the proportion of potassium salt modifiers, the number of areas with small curvature is gradually increasing, the number of large curvature is gradually decreasing, and the number of medium curvature is almost unchanged. When the proportion of potassium salt modifier is 15% and ϕ ≤ 0.7, all enter the area below the medium curvature. When the addition of different modifiers, 15%KCl-DW has the best inhibition effect on P max and (dP/dt) max , while CH 3 COOK-DW and K 2 CO 3 -DW have better inhibition effect on Δ t 2 and Δ t 2. In general, when the hydrogen addition ratio is less than 70%, the addition of inhibitors can significantly reduce the explosion intensity. In terms of inhibition mechanism, we established the decomposition model of potassium salt modified dry water and found that potassium salt modified dry water will produce a large amount of gaseous K and KOH in the explosion system. And gaseous K and KOH will catalyze each other and combine with H and OH to form stable H 2 O, which significantly reduces the mass fraction of H and OH radicals in the chain reaction. The results of this paper provide a theoretical basis for the safe use of hydrogen-enriched methane fuel and the research and development of explosion emergency prevention and control technology. • The explosion suppression of potassium salt modified dry water on H 2 /CH 4 was studied. • The hierarchical inhibition model of H 2 /CH 4 explosion by dry water was defined. • Particle swarm optimization is adopted to optimize the decomposition parameters of DW. • Suppression mechanism of potassium salt modified dry water was analyzed. [ABSTRACT FROM AUTHOR]
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- 2024
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20. Experimental Study on Explosion Characteristics of LPG/Air Mixtures Suppressed by CO 2 Synergistic Inert Powder.
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Zhao, Enlai, Liu, Zhentang, Lin, Song, and Chu, Xiaomeng
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CARBON dioxide , *POWDERS , *EXPLOSIONS - Abstract
In order to study the explosion suppression characteristics of LPG/air mixture by CO2 synergistic inert powder, explosion suppression experiments were conducted in a 20 L explosion device. The results show that the explosion suppression effect of NaHCO3 powder is prior to Al(OH)3 powder under the condition of no CO2 synergy. As the mass concentration of inert powder increases, the peak value of explosion pressure Pex and the peak value of the pressure rise rate (dP/dt)ex decrease, and the explosion suppression effect gradually enhances. Gas–solid two-phase inhibitors exhibit more significant inhibitory effects than single-phase inhibitors. Increasing the volume fraction of CO2 or the mass concentration of inert powder can improve the explosion suppression effect. The explosion suppression effect of CO2/NaHCO3 is significantly better than that of CO2/Al(OH)3. The research results have certain significance for the prevention and control of LPG explosion accidents. [ABSTRACT FROM AUTHOR]
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- 2024
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21. 多孔材料对含重烃煤层气爆炸特性的 影响研究.
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向开军, 段玉龙, and 刘力文
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POROUS materials ,GAS explosions ,COALBED methane ,GAS dynamics ,GREENHOUSE gas mitigation ,FLAME spread - Abstract
Copyright of China Mining Magazine is the property of China Mining Magazine Co., Ltd. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2024
- Full Text
- View/download PDF
22. Suppression characteristics of water mist containing alkali metal compounds in natural gas explosions
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Zhenqi Liu, Xiaoxing Zhong, Yansen Lu, Di Zhu, Qiu Zhong, and Tengfei Chen
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Natural gas explosion ,Water mist contains potassium compound ,Explosion suppression ,Overfire range ,Overpressure drop rate ,Engineering (General). Civil engineering (General) ,TA1-2040 - Abstract
The natural gas explosion in semi-constrained spaces seriously jeopardize public safety. Water mist containing additive is an important method to reduce the disaster intensity. However, in actual scenarios, the explosion usually propagates for a certain distance before entering the mist area, which is more difficult to suppress the explosion. Therefore, the self-designed experimental system was used to recognize the suppression effect of water mist containing alkali metal compounds under the simulated scenario. The results show that the flame propagation distance was significantly reduced, the shortest overfire range was decreased by 40.0 % compared with the water mist condition. The peak overpressure and pressure rise rate also showed a significant decrease, the maximum pressure drop rate reached 72.3 %. When the explosion flame entered the atomized region, the turbulent disturbance generated by the atomization accelerated the mixture of combustion zone and the unburned area, which increases the possibility of consuming free radicals. Compared with the KCl and NaCl, the mist containing K2CO3 and Na2CO3 share higher suppression capacity. This study provides scientific guidance for the practical application of water mist explosion suppression.
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- 2024
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23. Experiment on the promoting-inhibiting effects on methane explosion by using haloalkanes
- Author
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Tao WANG, Zhe DONG, Yuhuai SHENG, Fan NAN, Zhe YANG, Peng YANG, Fan MENG, and Zhenmin LUO
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methane explosion ,haloalkane ,explosion suppression ,explosion promotion ,explosion pressure ,laminar burning velocity ,Mining engineering. Metallurgy ,TN1-997 - Abstract
Methane explosion is one of the major disasters that seriously threaten the safety of coal mine production, the development of efficient methane explosion suppression technology can effectively improve the prevention and control level of methane explosion accidents, and its focus is on the function of explosion suppression materials. In order to systematically study the effect of typical haloalkanes extinguishing agents on methane explosion, the effects of typical haloalkanes such as heptafluoropropane (C3HF7), hexafluoropropane (C3H2F6) and trifluoromethane (CHF3) on the ignition and explosion characteristics of methane were systematically studied by combining experimental tests and theoretical analysis. The effects of haloalkanes on methane explosion pressure parameters and laminar burning velocity were tested by a 20 L spherical explosive vessel and a self-developed Bunsen burner laminar flame propagation velocity system. The variation laws of peak explosion pressure, maximum pressure rise rate, laminar burning velocity, and laminar flame morphology evolution were obtained. The results show that with the increase of the added volume fraction, the haloalkanes had a double effect of promoting and inhibiting the methane explosion process. Under the chemical equivalent condition, only C3HF7 can first promote and then inhibit the peak explosion pressure and maximum pressure rise rate of methane, while CHF3 and C3H2F6 can inhibit the effect. The three haloalkanes all showed inhibition on the combustion rate of methane laminar flow. In the oxygen-poor condition, the three haloalkanes inhibited the peak explosion pressure, the maximum pressure boost rate, and the laminar burning velocity of methane. In general, C3H2F6 and C3HF7 have better inhibition effects on methane explosion pressure characteristic parameters and laminar burning velocity than CHF3. The theoretical analysis results show that the double effect of promoting and inhibiting the haloalkanes with the increase of the mixture volume fraction can be attributed to the competition between the improvement of the heat release characteristics of the system reaction and the inhibition of the key free radicals such as H, O, and OH by the main intermediates containing F. The results of this paper provide a theoretical basis for the theoretical research and technical development of methane explosion prevention and control.
- Published
- 2024
- Full Text
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24. Ultrasound coupled recrystallization to grow KH2PO4 crystals on mesoporous SiO2: Application to suppression of AlH3 explosion.
- Author
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Xue, Chenlu, Jiang, Haipeng, Zhu, Chenchen, and Gao, Wei
- Subjects
- *
RECRYSTALLIZATION (Metallurgy) , *RADICALS (Chemistry) , *HETEROGENOUS nucleation , *FREE radicals , *EXPLOSIONS , *MICROBUBBLE diagnosis - Abstract
AlH 3 is a promising hydrogen storage material, but poses an explosion risk when suspended in air. Herein, a low-cost and environmentally friendly composite explosion suppressant is prepared using ultrasound coupled cooling crystallization and applied to suppress AlH 3 explosions. Ultrasound-induced cavitation inhibits crystal agglomeration, resulting in fine KH 2 PO 4 crystals growing on the SiO 2 surface by heterogeneous nucleation, which significantly improves the suppression effect. The decomposition products of KH 2 PO 4 react with the flame radicals in the system to generate stable products, interrupting the chain reaction of flame radicals effectively. Furthermore, the complex mesoporous structure of SiO 2 absorbs flame radicals and increases the collision probability between the radicals and the pore walls, thus suppressing flame propagation. Our research provides an important theoretical support for the safe application of light metal hydrogen storage materials. • Fine KH 2 PO 4 crystals grow on the silica surface by heterogeneous nucleation. • SiO 2 adsorbed on the pores of AlH 3 prevents H 2 release, and absorbs flame radicals. • Free radicals from KH 2 PO 4 decomposition interrupt the flame radical chain reaction. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
25. 卤代烷气体灭火剂促进−抑制瓦斯燃爆特性试验.
- Author
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王涛, 董哲, 盛禹淮, 南凡, 杨哲, 杨鹏, 孟帆, and 罗振敏
- Abstract
Copyright of Coal Science & Technology (0253-2336) is the property of Coal Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2024
- Full Text
- View/download PDF
26. Experimental investigation and numerical analysis on the confined deflagration behavior of methane-air mixtures within the suppression of typical haloalkanes.
- Author
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Wang, Tao, Sheng, Yuhuai, Yu, Yingying, Cheng, Fangming, Ding, Xuhan, Qu, Jiao, Deng, Jun, Nan, Fan, and Luo, Zhenmin
- Subjects
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HEAT release rates , *NUMERICAL analysis , *HALOALKANES , *ADIABATIC temperature , *HALOCARBONS , *MIXTURES - Abstract
To investigate the mechanisms of haloalkanes in promoting and inhibiting explosions in methane-air mixtures, the halon alternatives of CHF 3 , C 3 HF 7 , and C 3 H 2 F 6 were selected as inhibitors. Experimental research was conducted in a 20-liter spherical explosion vessel to examine the promotional and inhibitory effects of these haloalkanes on methane-air mixtures. The adiabatic flame temperature, heat release rate, and concentrations of the key radicals were calculated. The results showed that C 3 H 2 F 6 , C 3 HF 7 , and CHF 3 all exhibited a dual effect, initially promoting and subsequently inhibiting explosions in fuel-lean methane-air mixtures. The critical explosion suppression volume fractions of C 3 HF 7 and CHF 3 were 1.5 times and 2.25 times that of C 3 H 2 F 6 , respectively, for the suppression of methane explosion at Φ = 1.2. Furthermore, C 3 HF 7 demonstrated a dual impact on the explosion of stoichiometric methane-air mixtures. From the perspective of reaction kinetics, for fuel-lean methane-air mixture (Φ = 0.8), a small volume of halogenated hydrocarbons led to an increase in the adiabatic flame temperature due to the heat release from critical fluorine-containing elementary reactions, thereby promoting the explosion. Under fuel-lean conditions, the introduction of a small volume of halogenated hydrocarbons led to an increase in the adiabatic flame temperature due to the heat release from critical fluorine-containing elementary reactions, thereby promoting the explosion. Simultaneously, these fluorine-containing reactions scavenged the key free radicals of H, O, and OH inhibiting the explosion process. These two effects competed with each other, ultimately determining the direction of the explosion process. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
27. Research progress on metal wire mesh porous materials
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MA Jun, WANG Jianzhong, WU Chen, LI Guangzhong, YANG Baojun, and AO Qingbo
- Subjects
metal wire mesh ,porous materials ,filtration separation ,catalyzing ,efficient heat transfer ,explosion suppression ,Mining engineering. Metallurgy ,TN1-997 - Abstract
Metal wire mesh porous materials are kinds of porous materials with the controllable pores, high specific surface area, high strength, and low cost, which have been widely used in the filtration separation fields of high temperature flue gas and slurry oil, because of the high permeability and high filtration precision. Furthermore, due to the high specific surface area, open pore structure, high porosity, high strength, and adjustable graded pore size, the metal wire mesh porous materials have been paid attention in the fields of photocatalysis, combustion engine emission abatement systems, efficient heat transfer, and explosion suppression. The structure and preparation methods of metal wire mesh porous materials were briefly introduced in this paper, the application progress on the fields of filtration separation, catalysis, efficient heat transfer, and explosion suppression was emphatically summarized, and the application prospect and development direction were also proposed.
- Published
- 2023
- Full Text
- View/download PDF
28. Reducing the unwanted deflagration enhancement of C3HF7 on fuel-lean hydrogen-air mixture by diluting CO2: An experimental and numerical research.
- Author
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Wang, Tao, Sheng, Yuhuai, Liang, He, Yu, Yingying, Cheng, Fangming, Li, Ruikang, Su, Bin, Qu, Jiao, Zhou, Shangyong, Deng, Jun, and Luo, Zhenmin
- Subjects
- *
HEAT release rates , *FUEL cells , *HYDROGEN as fuel , *CHEMICAL kinetics , *DILUTION , *CARBON dioxide , *TIME pressure - Abstract
To prevent the explosion hazards of hydrogen energy, in this work, the deflagration behaviors of H 2 -air mixtures at equivalence ratios from 0.6 to 1.4 under the effects of C 3 HF 7 and CO 2 are experimentally investigated. Deflagration pressure and time indexes at ambient pressure and temperature are obtained. The characteristic parameters of chemical kinetics are analyzed according to a detailed mechanism. The results suggest that C 3 HF 7 has dual effects of pressure enhancement and suppression with the rising volume ratio in fuel-lean H 2 -air mixtures. It is the F-involved reactions that govern the exothermic process, facilitate the comprehensive conversion of crucial free radicals, and augment the exothermicity of the principal reaction, leading to the elevation in peak pressure. Dilution of CO 2 would decrease the heat release rate of the F-involved reactions and reduce the explosion enhancement effect of C 3 HF 7. The results of this work are beneficial to the formulation of mitigation measures for hydrogen explosions. [Display omitted] • C 3 HF 7 plays dual effects of explosion promotion and suppression on fuel-lean hydrogen-air mixtures. • This deflagration enhancement effect of C 3 HF 7 is attributed to the F-involved reactions. • CO 2 would decrease the heat release of F-involved reactions and reduce the explosion enhancement effect. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
29. Experimental and numerical simulation study of hydrogen explosion suppression by a small amount of ethylene.
- Author
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Shang, Sheng, Bi, Mingshu, Zhang, Changshuai, and Gao, Wei
- Subjects
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FREE radical reactions , *HYDROGEN as fuel , *BURNING velocity , *FLAME stability , *FREE radicals - Abstract
Hydrogen safety is the foundation of hydrogen energy industry, but there is presently a shortage of high-efficiency safety protection technologies for hydrogen. Through a combination of experiment and simulation methods, this paper reveals the effective performance of ethylene in suppressing the hydrogen explosion behaviors in a 14 L closed spherical vessel at normal temperature and pressure. The experimental and simulation results show that a small amount of ethylene can increase the hydrogen generation path in the lean hydrogen chain reaction, thus enhancing the concentration of active free radicals and causing flame instability, which ultimately leads to an increase in explosion overpressure and laminar burning velocity. But on the whole, with the increase in ethylene volume fraction, the explosion parameters show a monotonically decreasing trend. This is because the addition of ethylene makes the hydrogen-oxygen chain reaction gradually transition to the inactive free radical chain reaction, resulting in the conversion of the active free radical to the inactive free radical, and the chain reaction rate is weakened. Finally, the explosion cannot occur. This result provides a novel idea for the research of new and efficient hydrogen explosion suppression materials. [Display omitted] • Effects of C 2 H 4 on flame and pressure of hydrogen were observed. • Hydrogen explosions can be effectively suppressed by C 2 H 4. • C 2 H 4 can change hydrogen-oxygen chain reaction pathways. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
30. Study on the inhibition of hydrogen explosion pressure and flame propagation by trifluoroiodomethane.
- Author
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Luo, Zhen-min, Nan, Fan, Cheng, Fang-ming, Xiao, Yang, Wang, Tao, Li, Rui-kang, and Su, Bin
- Subjects
- *
HYDROGEN flames , *DUST explosions , *FREE radical reactions , *TRIFLUOROIODOMETHANE , *BURNING velocity , *FLAME , *EXPLOSIONS , *HYDROGEN as fuel - Abstract
A 20L spherical device and a schlieren system were used to study the suppression effect of CF 3 I on the hydrogen explosion pressure and flame characteristics. The results show that CF 3 I can promote and inhibit the pressure parameters of hydrogen under lean fuel, but only inhibit the pressure parameters of hydrogen under equivalence ratios and rich fuel. Such as, φ = 0.6, adding 10 % CF 3 I, the maximum explosion pressure increased by 8.8 %. φ = 1, adding 5 % CF 3 I, the maximum explosion pressure decreased by 25 %. Different from the explosion pressure, the laminar burning velocity of hydrogen with different equivalence ratio decreases gradually with the increase of CF 3 I concentration. Numerical simulation was used to reveal the mechanism of CF 3 I inhibiting hydrogen. The results show that the concentration of active free radicals(H, O, OH) decreases with the increase of trifluoroiodomethane concentration. Further analysis on the rate of production and sensitivity of H free radicals found that R822 and R839 are the main generation reactions of H free radicals in the fluorine- and iodine-containing elemental reactions, and R1397, R1396, R1391 and R859 are the main consumption of H free radicals reaction. The elementary reaction with the greatest inhibitory effect on H free radicals is R1391, and the elementary reaction with the greatest promoting effect is R850. • CF 3 I has two effects of promoting and suppressing hydrogen explosion pressure. • Analysis of the effect of suppressant on hydrodynamic instability. • CF 3 I has inhibitory effect on laminar burning velocity of hydrogen. • The kinetic mechanism of CF 3 I suppressing hydrogen explosion was analyzed. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
31. Exceptional Performance of Flame-Retardant Polyurethane Foam: The Suppression Effect on Explosion Pressure and Flame Propagation of Methane-Air Premixed Gas.
- Author
-
Li, Changhua, Zhang, Guangyi, and Yuan, Bihe
- Subjects
- *
URETHANE foam , *DUST explosions , *MANUFACTURING processes , *POROUS materials , *FIREPROOFING agents , *FOAM , *GAS explosions , *FLAME - Abstract
A self-built gas explosion testing platform was used to explore the quenching effect of flame-retardant polyurethane foam on a gas explosion. The effect of the foam's filling position and length on the explosion suppression performance was explored. The results demonstrate that polyurethane foam exhibits an excellent flame-quenching performance, with a minimum of a 5 cm length of porous material being sufficient to completely quench the flame during propagation. Furthermore, the attenuation function of this porous material on the pressure wave is insignificantly affected by the change in ignition energy. Compared with the explosive state of the empty pipeline, the best suppression effect is obtained when the polyurethane foam is 20 cm in length with a filling position at 1.8 m, and the maximum explosion pressure and maximum rise rate are attenuated by 86.2% and 84.7%, respectively. This work has practical significance for the application of porous materials in explosion suppression and explosion-proof technologies in the chemical industrial processing and oil (gas) storage fields. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
32. Studying the Effects of Wave Dissipation Structure and Multiple Size Diffusion Chambers on Explosion Shock Wave Propagation.
- Author
-
Liu, Wei, Xu, Xiangyun, Yi, Huahui, and Zhu, Lifan
- Subjects
- *
THEORY of wave motion , *GAS explosions , *EXPLOSIONS , *COAL gas , *MINE safety , *SHOCK waves - Abstract
Explosion chambers are crucial to the technology used to prevent coal mine gas explosions. Investigating the shock wave propagation law at various coal mine tunnel cross-sections helps ensure mine safety. A self-built, highly explosive experimental setup was used to conduct empirical research on straight tubes, eight sizes of single-stage explosion chambers, and multi-stage tandem explosion chambers. Ansys Fluent numerical simulation software constructed five different tandem explosion chamber models. The wave dissipation efficiency of various types of explosion chambers was calculated, the propagation law and process of shock waves across multiple explosion chambers were examined, and the best size and type of explosion chambers were summarized to increase the wave dissipation efficiency of single-stage explosion chambers. Gun silencers inspired these models. The findings indicate that the three-stage tandem explosion chamber is the best diffusion tandem combination form, the 60° silencer-type explosion chamber is the best single-stage explosion chamber modification program, and the 500 mm × 500 mm × 200 mm explosion chamber is the best single-stage explosion chamber. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
33. Experimental study on the effect of initial accumulation pattern on gas explosion and explosion suppression in a real roadway
- Author
-
Chunlian Cheng, Rongjun Si, Lei Wang, Quansheng Jia, Chengpeng Xin, and Xu Chen
- Subjects
Actual roadways ,Gas explosion ,Gas accumulation ,Explosion wave energy ,Chemical reaction kinetics ,Explosion suppression ,Engineering (General). Civil engineering (General) ,TA1-2040 - Abstract
In real roadways, gas is prone to accumulate, which in turn can lead to explosive hazards. The state of gas accumulation has a significant impact on the degree of disaster caused by gas explosive hazards. In this study, gas explosion propagation in complex situations was investigated in the actual roadway. The mechanism of explosion suppression was explored from the perspective of kinetic analysis of chemical reactions. It is found that the peaks of explosion pressure occur in the gas accumulation zone. The length of explosion flame is 3–5 times larger than that of the initial gas accumulation zone. As the initial accumulation volume increases, the flame propagation velocity (FPV), maximum explosion pressure (MEP) and flame zone length all increase. ABC Powder can effectively suppress explosion flames of gas with different gas accumulation patterns. A prediction model of gas explosion wave energy in the roadway is proposed. The explosion wave energy increases with increasing overpressure ratio. The explosion wave energy decays significantly after 80 m because of explosion suppression. The explosion suppression of ABC powder is a synergistic effect of surface cooling, dilution, physical isolation and chemical mechanisms. The free radical ions generated by the pyrolysis of ABC powder destroy the structure of the flame and make the reaction more difficult, which corresponds to an increase in the critical flame temperature and makes the gas phase dilution effect easier to achieve.
- Published
- 2023
- Full Text
- View/download PDF
34. Experimental study of NaHCO3/modified vermiculite composite powder for methane explosion suppression.
- Author
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Yang, Ke, Li, Lekai, Ji, Hong, Ji, Dongyu, Xing, Zhixiang, Jiang, Juncheng, and Du, Xiaoyang
- Subjects
- *
SURFACE stability , *CHEMICAL reactions , *VERMICULITE , *CHEMICAL chains , *PARTICLE analysis - Abstract
• NaHCO 3 /modified vermiculite composite powder is prepared by a mechanochemical technology. • NaHCO 3 /modified vermiculite composite powder has a significant effect on reducing the relevant explosion parameters. • Composite powder displayed better inhibition performance than the monomers. • Adding 360 mg 50 wt% NaHCO 3 /modified vermiculite composite powder had the best suppression effect. Using a self-constructed experimental platform with 9.5 % methane as the explosive gas, the effects of various masses of NaHCO 3 , vermiculite, and NaHCO 3 /modified vermiculite composite powders on the explosion pressure, flame propagation shape, and flame propagation velocity of methane were investigated. The composite powders' thermal stability and surface microstructure were examined, along with the mechanism of explosion suppression, using thermogravimetric analysis, XRD analysis, and particle size analysis. By comparing various data, 50 wt% NaHCO 3 /modified vermiculite composite powder with a mass of 360 mg showed the best detonation suppression effect, with Pmax and (dP/dt)max reduced by 53.3 % and 87.1 %, respectively, and Pmax arrival time extended by 142.9 %. The flame disappearance time reached 467 ms, which increased by 165.3 %, and the maximum flame propagation speed decreased by 40 %. Methane explosion suppression is achieved by adding NaHCO 3 /modified vermiculite composite powder, which prevents flame propagation and breaks the methane explosion chain reaction by chemical and physical suppression of methane explosion. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
35. Effect of rear part structure of duct and nozzle position on gas explosion prevention.
- Author
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Lu, Chang, Ban, Chengwei, Meng, Qi, Duan, Zheng, Liu, Jingang, and Yu, Minggao
- Subjects
- *
GAS explosions , *NOZZLES , *FIREFIGHTING , *GAS wells , *FLAME spread , *EXPLOSIONS - Abstract
To better reduce the gas explosion hazard, a method of explosion prevention was developed, through which the explosion was totally suppressed. The corresponding system was designed to quench the explosion flame and terminate the propagation by extinguishing the agent sprayed after an explosion. The lower limit quantity of agent of ABC powder (NH4H2PO4 powder) required to quench the flame was considered as the difficulty standard for explosion prevention. The main experimental duct was 3.0 m long and horizontal arrangement. The rear duct was 0.5 m long, which was placed at different angles with the horizontal main duct. And its cross-section was varied in different experiments. The results showed that the 90° duct structure was most conducive to preventing the explosion, in which 10 g ABC powder was needed, while 50 g powder was needed in 180° duct structure. The cross-section reduction of the rear duct was also conducive to explosion prevention. At the positions where the nozzles were set up, the slower the flame spread, the easier the explosion prevention could be achieved. When the nozzles were set at different positions, the amount of powder required to prevent the explosion varied greatly, ranging from 5 g to more than 80 g. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
36. Suppression characteristics of multi-layer metal wire mesh on premixed methane-air flame propagation
- Author
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Xiangrui Feng, Hongming Zhang, Fangyuan Si, Jiawei Dou, Mingxuan Li, Long Wu, Shengkang Wang, and Lanming Zhao
- Subjects
gas explosion ,premixed flame ,explosion suppression ,metal wire mesh ,flame propagation ,Technology - Abstract
Metal wire mesh is widely used in the energy industry for its excellent protective properties as a fire stopping and explosion isolating material. In this study, the suppression characteristics of different layers of metal mesh on the dynamic behavior of premixed methane-air flame propagation were studied experimentally. A high-speed photographic schlieren system was used to photograph the explosion process to capture the changes in the microstructure of the flame, and high-frequency pressure sensors and micro-thermocouple measurements were used to capture the flame explosion pressure and temperature. The experimental results show that the suppression effectiveness of wire mesh is a reflection of the coupling of explosive flame propagation behavior and combustion state in the pipe. Increasing the number of mesh layers and mesh density can destroy the microstructure of the premixed methane-air flame front and hinder the progress of flame propagation. Increasing the number of wire mesh layers will delay the peak time of premixed flame propagation speed and reduce the peak speed values of flame propagation. Wire mesh has a pronounced attenuation effect on premixed flame temperature and explosion overpressure. The maximum flame temperature attenuation rate is 34.99%–60.95%, and the maximum explosion overpressure attenuation rate is 33.70%–74.02%. And the suppression effect is greatly enhanced as the increase of mesh layers.
- Published
- 2023
- Full Text
- View/download PDF
37. The suppression and CO elimination performance of Co3O4 dust cloud for methane-air mixture explosion.
- Author
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Li, Jia, Wang, Xiao, Shen, Zhiyuan, He, Sheng, Li, Junyi, Shi, Bobo, Wu, Jianguo, Guan, Lianhe, Chen, Xinyu, Xu, Xuan, Chen, Xiaoyu, and Zhou, Fubao
- Subjects
- *
FLAME , *MINE accidents , *THERMAL shock , *CATALYTIC oxidation , *CATALYTIC activity , *EXPLOSIONS - Abstract
• A novel method for simultaneously suppressing explosion and eliminating CO product was proposed in this study. • The catalytic oxidation activity of the Co 3 O 4 catalyst decreased significantly under the strong transient thermal shock. • CO concentration decreased more than 56 %, and the effective evacuation time was extended more than 52 % due to Co 3 O 4 dust cloud • The CO elimination capacity of the Co 3 O 4 dust cloud significantly increased with the increase in methane concentration and Co 3 O 4 powder usage. • For the methane-air mixture explosion accidents in mines, Co 3 O 4 dust cloud can reduce the hazard of methane-air mixture explosions dramatically. This paper experimentally studied the effect of Co 3 O 4 dust clouds on the methane-air mixture explosion characteristics and post-explosion CO concentration, aiming to propose a novel method for simultaneously suppressing explosion and eliminating CO product. The Co 3 O 4 catalyst was synthesized utilizing the co-precipitation method. We varied the methane concentration and Co 3 O 4 dust cloud concentration to investigate their effects on the flame propagation behavior, maximum explosion overpressure (P m), flame combustion time (t c), and the gaseous product concentration. The hazard of the gaseous product was evaluated by the effective escape time (t e) based on the Fraction Effective Dose (FED) mathematical model. The results demonstrated that the Co 3 O 4 dust cloud could significantly reduce the explosion severity and CO concentration. Furthermore, the higher the concentration of Co 3 O 4 dust clouds, the more significant the explosion suppression and CO elimination performance, which was as a result of the significant increase in the contact area and collision probability between the Co 3 O 4 particles and the reaction components increased. Compared to traditional inhibitors that only reduce the severity of an explosion, Co₃O₄ could not only significantly reduce the explosion severity, but also quickly eliminate post-detonation CO. The method proposed in this paper could effectively reduce the hazard of methane-air mixture explosion, which was of great practical significance for ensuring the safety of personnel involved in the risk. [Display omitted] [ABSTRACT FROM AUTHOR]
- Published
- 2025
- Full Text
- View/download PDF
38. Experimental study on the effectiveness and safety of cement powder on extinguishing metal magnesium fires based on pneumatic conveying technology
- Author
-
Long Yan, Ning Wang, and Zhisheng Xu
- Subjects
Metal magnesium fires ,Cement powder ,Fire suppression ,Explosion suppression ,Pneumatic conveying technology ,Engineering (General). Civil engineering (General) ,TA1-2040 - Abstract
A pneumatic conveying powder device was carried out to investigate the fire-extinguishing performance of cement powder against metal magnesium fire. The fire suppression test shows that pneumatic conveying can effectively transport cement powder to the combustion area for suppressing metal magnesium fire, and the fire-extinguishing time increases with the fire load of metal magnesium. The fire suppression effect of cement powder in metal magnesium fire is ascribed to the formation of a thermally insulation layer as physical barrier concomitant with heat absorption during pyrolysis process that effectively weaken the heat transfer and reduces the combustion intensity, as supported by the morphology and DSC analysis. The results of explosion suppression test reveal that cement powder has a significant inhibitory effect on reducing the explosion max-pressure and max-pressure rise rate of methane explosion, exhibiting a high-level security in the fire-extinguishing process. This work provides an effective and safe strategy for extinguishing metal magnesium fires.
- Published
- 2022
- Full Text
- View/download PDF
39. Inhibitory effect and mechanism of urea on wheat starch explosion.
- Author
-
Xia, Yueshuang, Guan, Wenling, Ren, Changxing, Dong, Chengjie, and Zhang, Wang
- Subjects
- *
CHEMICAL models , *CHEMICAL kinetics , *FREE radicals , *RADICALS (Chemistry) , *FLAME - Abstract
[Display omitted] • The inhibition efficiency of urea on wheat starch explosion was determined. • The concept of flame projected area was used to characterize the flame size. • The mechanism of chemical inhibition of urea on starch explosion is revealed. This paper aimed to determine the inhibitory effect of urea on wheat starch explosion and reveal its chemical inhibition mechanism. Dust explosion pressure tests and flame propagation experiments were conducted using 20 L Siwek spheres and modified Hartmann tubes. The inhibitory mechanism of urea on wheat starch explosion was investigated using the chemical kinetic model Gri3.0. Results demonstrated that urea can significantly reduce the starch explosion pressure and decrease the probability of explosion. Urea also effectively reduced the flame size (projected area, height) of starch combustion, slowed down flame propagation velocity, and suppressed reburning. When the inerting ratio of urea in starch reached 0.2, the reburning phenomenon disappeared. When the inerting ratio of urea reached 0.4, flame propagation was effectively controlled, and the flame projected area was reduced by 95 %. Analysis of the inhibitory mechanism of urea on starch explosions revealed that after capturing H and OH radicals in the combustion reaction, the pyrolysis products of urea, NH 3 and HNCO, generated NH 2 , NH, HNO, and NCO. These intermediates further captured H, O, and OH and formed a reaction chain that consumed key free radicals, which slowed down the reaction rate of important elementary reactions in the combustion process and thus inhibited combustion. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
40. Effect of opening blockage ratio on the characteristics of methane/air explosion suppressed by porous media.
- Author
-
Wang, Jian, Liu, Guilong, Zheng, Ligang, Pan, Rongkun, Lu, Chang, Wang, Yan, Fan, Ziyao, and Zhao, Yongxian
- Subjects
- *
EXPLOSIONS , *POROUS materials , *COAL mining accidents , *GAS explosions , *MANUFACTURING processes , *FIREFIGHTING , *FOAM - Abstract
Gas explosion is a common serious accident in underground coal mines and industrial production processes. Porous media, due to its special cellular structure, has a significant effect on stopping the propagation of pressure and flame, which can effectively reduce the explosion hazard. In this study, the explosion suppression effect of Fe-Ni and Cu foams with different pore sizes (20 and 40 holes pores per inch (ppi)) was experimentally investigated and comparatively analyzed at opening blockage ratios (OBR) equal to 0.36, 0.64 and 0.84, respectively. The results demonstrate that Fe-Ni foam with 20ppi quenches the flame only under the OBR of 0.84, which indicates that the larger the OBR is, the better the explosion suppression effect is. However, under the OBR of 0.64, the porous media achieve an enhanced quenching efficiency and the shortest quenching time. In addition, when the vent area is relatively large, the obstacle effect of porous media is stronger than its pressure absorption capacity, thus leading to an increased pressure in the explosion area. The lowest peak overpressure attenuation rate, − 25.9%, is observed for 40ppi Fe-Ni foam under the OBR of 0.36. In general, the OBR is positively correlated with the depressurization capacity. Among all the cases used in this study, the 20ppi Cu foam boasts the highest upstream and downstream peak overpressure attenuation rates under three OBRs, 0.86%, and 6.33%, respectively. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
41. Experimental and theoretical study on the suppression effect of CF3CHFCF3 (FM-200) on hydrogen-air explosion.
- Author
-
Fan, Rujia, Wang, Zhirong, Guo, Wenjie, and Lu, Yawei
- Subjects
- *
BURNING velocity , *EXPLOSIONS , *PATH analysis (Statistics) , *FREE radicals - Abstract
This study experimentally and numerically determined the effect of FM-200 on H 2 /air explosion. Firstly, the explosion pressure was investigated to evaluate the suppression efficiency. The results indicated that the effect of FM-200 on H 2 /air explosion was quite different for various equivalence ratios. FM-200 could enhance the explosion at lean mixture, but suppress the explosion at rich mixture. Then, the burning velocity, heat production and temperature free radicals were investigated. The results also demonstrated that FM-200 exhibited stronger suppression effect in rich explosion. In addition, the increase of free radicals indicated the enhancement effect of FM-200 at lean explosion. Last, the analysis of sensitivity and reaction path was performed to understand the suppression kinetics. It was shown that R1466 and R1468 could suppress explosion at Φ = 1.3 and 1.6, however, they changed into promoting explosion at Φ = 0.8 and 1.0. Moreover, the reaction path analysis indicated that CHF:CF 2 →CHF:O→CO could enhance explosion at Φ = 0.8. For CHF:CF 2 →CH 2 F→HF, it played an important role in scavenging H to suppress explosion at Φ = 1.6. Furthermore, it was indicated that there was a competition between the enhancement and suppression effect at Φ = 1.3. • Several characteristic parameters of hydrogen explosion with FM-200 addition were analyzed. • The explosion was enhanced with small volume fraction FM-200 addition at lean explosion. • Reaction R1466 and R1468 could suppress explosion at rich mixtures; but promote explosion at lean mixtures. • The analysis of reaction path was performed to understand the suppression kinetics. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
42. Research Progress of Explosion Suppression and Isolation Technology of Gas and Coal Dust
- Author
-
SI Rongjun, WANG Lei, JIA Quansheng
- Subjects
gas coal dust explosion ,explosion flame ,flameproof ,explosion suppression ,flame-proof shed water ,mechanical flameproof device ,Mining engineering. Metallurgy ,TN1-997 - Abstract
In this paper, the research progress and development trend of gas and coal dust explosion suppression and isolation technology in China are reviewed and discussed from the aspects of basic research, passive explosion suppression and isolation technology, active explosion suppression and isolation technology and development trend. Large-scale test tunnels and test pipes of various diameters are used to conduct experimental research on the propagation law of gas and coal dust explosion flame and shock wave, which provides a theoretical basis for the development of explosion suppression and isolation technology. The active explosion suppression and isolation technology and equipment are developed to detect the explosion signal in advance, spray the explosive inhibitor actively, isolate and extinguish the flame. The passive explosion isolation technology and equipment, such as rock powder shed, water tank shed and water bag shed, have been popularized and applied in underground coal mines in China. The sealed water bag and automatic water injection device are further developed to solve the problems of easy evaporation and pollution of water. The mechanical explosion isolation device has been developed and the passive explosion isolation technology and equipment system have been improved. The technology of gas coal dust explosion suppression and flameproof adapts to the development trend of intelligent and unmanned coal mines. It realizes hierarchical start-up and linkage control through intelligent means to form a regional joint control technology to achieve effective control of gas (coal dust) explosion disasters.
- Published
- 2020
- Full Text
- View/download PDF
43. Explosion suppression effect and mechanism analysis of ceramic foam in the horizontal pipe.
- Author
-
Yin, Feifei, Nie, Baisheng, Wei, Yueying, Lin, Shuangshuang, and Wang, Xiaotong
- Subjects
- *
EXPLOSIONS , *GAS explosions , *PIPELINE transportation , *NATURAL gas pipelines , *FOAM , *CERAMICS , *TRANSPORTATION engineering , *PIPE - Abstract
Ceramic foams are potential materials for explosion suppression due to their complex three-dimensional porous structure and strong wave absorption capabilities. The ability of ceramic foams to suppress methane/air explosion was investigated in a large-scale horizontal pipe. The factors of pore size and thickness of the ceramic foam were taken into consideration, and the explosion overpressure and explosion energy were compared and discussed collectively. Furthermore, mechanisms for the suppression of ceramic foams were also analyzed. Results indicated that ceramic foam has a good quenching effect on explosions compared to the conditions in an empty pipe. It can effectively decrease the explosion overpressure and explosive energy, thus limiting the flame propagation owing to insufficient fuel supply. The tendency for maximum explosion overpressure and explosion energy varied significantly by changing the thickness and pore size. It is worth noting that the attenuation rate of the maximum overpressure is generally greater than 50%, and the Al2O3 ceramic foam showed a better suppression performance than SiC. Additionally, the inhibitory effect is most obvious at 15 mm-20ppi Al2O3 and 30 mm-30ppi SiC, where the maximum explosion overpressure was reduced to 0.11 MPa and 0.19 MPa. However, the reduction of explosive energy is the combined result of the thickness and size of the pores. Overall, 15 mm Al2O3 and 30 mm SiC were more advantageous in suppressing gas explosions. This work supports the mechanism for preventing and suppressing gas explosions while using ceramic foam, and it might serve as a technological reference for the construction of explosion-proof devices. It is essential to avoid and control explosions in gas pipelines, thereby successfully enhancing the safety guarantee in gas pipeline transportation and engineering applications. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
44. The Choice of Optical Flame Detectors for Automatic Explosion Containment Systems Based on the Results of Explosion Radiation Analysis of Methane- and Dust-Air Mixtures.
- Author
-
Khokhlov, Sergey, Abiev, Zaur, and Makkoev, Viacheslav
- Subjects
DUST explosions ,OPTICAL detectors ,COAL dust ,OPTICAL interference ,EXPLOSIONS ,RADIATION ,MIXTURES - Abstract
A review of the existing optoelectron monitoring devices revealed that the design of optoelectron detectors of the mine atmosphere does not sufficiently take into account the factor of external optical interference. This includes any extraneous source of thermal emission: a source of artificial lighting or enterprises. As a consequence, the optoelectron detectors -based safety systems currently installed at mining sites are not able to ensure properly the detection of the ignition source in the presence of optical interference. Thus, it is necessary to determine the working spectral wavelength ranges from methane and coal dust explosions. The article presents the results of experimental research devoted to the methane-air mixture and coal dust explosion spectral analysis by means of the photoelectric method. The ignition of a methane-air mixture of stoichiometric concentration (9.5%) and coal dust of size characterized by the dispersion of 63–94 microns and concentration of 200 g/m
3 was carried out in a 20 L spherical chamber with an initial temperature in the setup of 18–22 °C at atmospheric pressure. Then, photometry of the explosion light flux was conducted on a photoelectric unit. Operating spectral wavelength ranges from methane and coal dust explosions were determined. For the methane-air mixture, it is advisable to use the spectral regions at the maximum emission of 390 and 900 nm. The spectrum section at the maximum emission of 620 nm was sufficient for dust-air mixture. It enabled us to select the wavelength ranges for automatic explosion suppression systems' launching references. This will exclude false triggering of the explosion suppression system from other radiation sources. The research results will help to improve the decision-making credibility of the device in its direct design. The results will be used in further research to design noise-resistant optical flame detection sensors with a high response rate. [ABSTRACT FROM AUTHOR]- Published
- 2022
- Full Text
- View/download PDF
45. Investigation on suppression of melamine polyphosphate on acrylonitrile‐butadiene‐styrene dust explosion.
- Author
-
Song, Ning, Luo, Taiyu, Yu, Yuan, Suo, Yifan, Chen, Zhongwei, Chen, Tingting, Zhang, Qingwu, Jiang, Juncheng, and Zhu, Guiming
- Subjects
DUST explosions ,MELAMINE ,IGNITION temperature ,THERMAL analysis ,THERMAL stability ,NITRILE rubber - Abstract
There is a possibility of dust explosion during acrylonitrile‐butadiene‐styrene (ABS) production including cutting, grinding and machining. The suppression effect of melamine polyphosphate (MPP) on the explosion severity and ignition sensitivity of ABS dust, including maximum explosion pressure (Pmax), maximum explosion index (Kst), minimum ignition energy (MIE) and minimum ignition temperature (MIT), was systematically investigated. MPP had an inhibitory effect on ABS dust explosion, and the explosion suppression effect was proportional to the mass fraction of MPP. Through the analysis on thermal decomposition behavior, gas‐phase products and the explosion residue, the explosion suppression mechanism of MPP on the ABS dust was studied and proposed. According to the thermal analysis and explosion residue analysis results, it could be seen that the addition of MPP improved the thermal stability of the ABS dust and promoted the formation of dense carbon on the surface of ABS particles. Gas‐phase products results showed that thermal decomposition of MPP produced NH3, CO2 and H2O, which consumed and diluted the oxygen concentration in the explosion zone. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
46. Effects of mesh aluminium alloys and propane addition on the explosion-suppression characteristics of hydrogen-air mixture.
- Author
-
Yang, Zhongkun, Zhao, Kun, Song, Xianzhao, Li, Bin, Zhang, Dan, and Xie, Lifeng
- Subjects
- *
ALUMINUM alloys , *FOSSIL fuels , *PROPANE , *DUST explosions , *MIXTURES , *EXPLOSIONS - Abstract
Accidents involving hydrogen explosions occur frequently, yet systematic methods of explosion suppression have not been investigated and applied. Therefore, this paper studied the deflagration characteristics in hydrogen with the addition of propane in the tube filled with mesh aluminium alloys (MAAs). The effects of different propane contents and different filling densities (the mass of MAAs per unit volume in a vessel) on the explosion suppression of the premixed gas are examined. The results show that propane and MAAs can effectively suppress the hydrogen-air explosion. However, MAAs have multiple suppression/promotion effects on the propane-hydrogen explosion. Based on the mathematical model, the dominant effect of MAAs changes abruptly toward the promoting effect when the hydrogen content exceeds 72.26% of the premixed gas stoichiometric concentration. It is also found that an increase in filling density would have a beneficial effect on explosion suppression. The study results provide references for preventing hydrogen and hydrogenated hydrocarbon fuels explosions and optimizing the performance of MAAs. [Display omitted] • Propane and MAAs can effectively suppress the hydrogen explosion. • MAAs have multiple suppression/promotion effects on the propane-hydrogen explosion. • An abrupt change occurs when the hydrogen content exceeds 72.26%. • The greater filling density of MAAs has a better explosion suppression effect. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
47. Effects of nitrogen addition on vented hydrogen–air deflagration in a vertical duct.
- Author
-
Guo, Jin, Wang, Xuebiao, Zhang, Kai, Chen, Hao, Du, Saifeng, and Yang, Fuqiang
- Subjects
- *
NITROGEN , *FLAME , *HYDROGEN , *OSCILLATIONS , *EXPLOSIONS , *DISTANCES - Abstract
In this paper, experiments were performed to investigate the coupling effects of venting and nitrogen addition ratio (χ) on flame behavior and pressure evolution during hydrogen–air deflagration within and outside a 1-m-high vertical duct with a vent on its top. Experimental results reveal that χ has significant effects on the pressure–time histories in the duct. Helmholtz oscillations of the internal overpressure were observed in all tests, and acoustic type oscillations appears in the tests only for χ = 25% and 30%. For a certain χ, the maximum overpressure (Pmax) increased with the distance to the vent, i.e., the highest overall explosion overpressure was attained near the duct bottom; however, the difference in Pmax between various measuring points decreases with an increase in χ. In all tests, a pressure peak in the duct was observed shortly after external explosion. The maximum internal and external overpressure decreased as χ was increased. • Effect of ratio of nitrogen addition (χ) on vented hydrogen–air deflagration was studied. • χ significantly affect the pressure–time histories in the duct. • The maximum internal and external overpressure decreased as χ was increased. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
48. Study on the combined effect of duct scale and SBC concentration on duct-vented methane-air explosion.
- Author
-
Yu, Minggao, Fu, Yuanpeng, Zheng, Ligang, Pan, Rongkun, Wang, Xi, Yang, Wen, and Jin, Hongwang
- Abstract
A gas explosion is often vented to a safe location by means of a discharge duct. However, the presence of a discharge duct increases the explosion severity in the vessel, inducing a higher explosion overpressure compared to a simply vented vessel. To reduce the explosion overpressure in the vessel, an experimental study was performed to suppress the methane-air explosions in a 5 L vessel connected to a discharge duct of different scales (e.g., length and diameter) and with various sodium bicarbonate concentrations. The results show that the initial flame propagation process in the vessel was basically similar in the simply vented vessel and in the vessel vented through a discharge duct (i.e., ducted-vessel). In the middle and late stages of flame propagation in the vessel, the flame fragmentation was more pronounced for the ducted-vessel. Moreover, the degree of flame fragmentation in the vessel increased with the duct length. The flame structure in the vessel was more irregular for a larger vent coefficient (K v = 9.75). The more pronounced quenching in the short duct (250 mm duct) is related to the high inhibition efficiency due to the leakage of a large amount of sodium bicarbonate (SBC) powder into the discharge duct while in the long duct (750 mm duct) the disturbance is due to the strong turbulence. The appropriate SBC concentration can transform the mechanism for the pressure rise in the vessel. At high powder concentrations the maximum pressure in the vessel is dictated by the flame reaching the vessel wall, while at low concentrations the maximum pressure is dominated by the pressure (i.e., burn-up) in the discharge duct. There is an approximately linear correlation between the maximum pressure and the average flame velocity in the discharge duct for a given powder concentration, and a linear relationship between the maximum pressures in the vessel and the duct independent of the SBC concentration. Through the analysis of the flame dynamics (e.g. flame morphology, flame propagation velocity and turbulence) and friction resistance induced by the varying duct scales, the suppression efficiency of SBC powder in the vessel is higher for a longer and narrower discharge duct. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
49. 惰性气体对KHCO3冷气溶胶甲烷抑爆性能的影响研究.
- Author
-
王燕, 林森, 李忠, 李璐, 温小萍, and 纪文涛
- Subjects
GAS explosions ,NOBLE gases ,COAL mining ,AEROSOLS ,EXPLOSIONS ,MICROBIOLOGICAL aerosols ,COLD gases - Abstract
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- Published
- 2021
- Full Text
- View/download PDF
50. Suppression of hydrogen-air explosions by hydrofluorocarbons.
- Author
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Gao, Mengdi, Bi, Mingshu, Ye, Lili, Li, Yanchao, Jiang, Haipeng, Yang, Mingrui, Yan, Caicai, and Gao, Wei
- Subjects
- *
DUST explosions , *FLAME stability , *BURNING velocity , *HYDROGEN flames , *THERMAL expansion , *EXPLOSIONS , *HYDROFLUOROCARBONS - Abstract
This study examines the suppression effectiveness of fluorinated species CHF 3 and C 2 HF 5 on the premixed hydrogen-air explosions experimentally and numerically. The results demonstrate that as for stoichiometric and rich hydrogen-air mixtures, both CHF 3 and C 2 HF 5 can effectively reduce thermal expansion ratio and increase flame thickness, and then reduce the influence of hydrodynamic instability on the flame acceleration. Laminar burning velocity, the maximum of explosion pressure, the maximum rate of pressure rise and the absolute value of pressure impulse all decrease with increasing suppressant concentration at various equivalent ratios. The maximum of explosion pressures for stoichiometric flames is decreased by 11.54 % with 2 % CHF 3 added, and decreased rapidly by 40.39 % with 2 % C 2 HF 5 added. The hydrogen-rich mixtures cannot be ignited when C 2 HF 5 content reaches 10 %. Numerical simulations have confirmed that both CHF 3 and C 2 HF 5 can effectively reduce the concentration of active radicals with the decrease order of H > OH > O. C 2 HF 5 is more effective in suppressing explosions than CHF 3 by converting more H atoms to HF formation through the elementary reactions CHF 2 + H <=> CHF + HF, CF 2 :O + H <=> CF:O + HF, and CF 2 + H = CF + HF. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
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