Enhanced Mechanism of Metal Oxides on the Fire Spread of Magnesium Dust Layer

doi:10.12068/j.issn.1005-3026.2023.12.014

Abstract

Abstract: Solid inerting agents that readily decompose can intensify the combustion of the magnesium dust layers. In order to explore whether metal oxides that are less prone to decomposition can inhibit the combustion of the magnesium dust layers， TiO₂， MgO and CaO were used for experimental research. The results show that TiO₂， MgO and CaO significantly enhance the combustion intensity of the magnesium dust layer fire spread when the mass fraction is less than 75%， and the flame phase transitions from surface heterogeneous combustion of pure magnesium dust layers to gas phase combustion. TiO₂ enhanced the fire spread behavior by chemical reaction with magnesium powder， and the fire spread rate of dust layer increased by more than 50 times under the condition of perfectly reacting between TiO₂ and Mg (mass fraction of 63%). MgO and CaO enhance the fire spread behavior of the magnesium dust layer by increasing the particle spacing of magnesium powder and slowing down the formation of dense oxide layer. The actual production process should pay close attention to the contact conditions of magnesium dust and metal oxides， and the research results can provide a theoretical basis for magnesium dust protection.

Key words: dust layer fires; metal oxides; magnesium dust; fire spread velocity; flame form

CLC Number:

TP20

CHEN Yang-yang， MENG Fan-yi， CAI Jing-zhi， YUAN Chun-miao. Enhanced Mechanism of Metal Oxides on the Fire Spread of Magnesium Dust Layer[J]. Journal of Northeastern University(Natural Science), 2023, 44(12): 1778-1784.

References

[1]Liu W，Tan W Y，He H W，et al.Electrodeposition of self-supported Ni-Mg-La electrocatalyst on Ni foam for efficient hydrogen evolution reaction［J］.Electrochimica Acta，2022，411:140058.
[2]Kaushik V，Nithish K B，Sakthi K S，et al.Magnesium role in additive manufacturing of biomedical implants-challenges and opportunities［J］.Additive Manufacturing，2022，55:102802.
[3]李刚，胡朋，张洋洋，等.不同弯型管道内粉尘爆炸传播规律［J］.东北大学学报(自然科学版)，2020，41(9):1316-1320.(Li Gang，Hu Peng，Zhang Yang-yang，et al.The propagation law of dust explosion in different curved pipes［J］.Journal of Northeastern University (Natural Science)，2020，41(9):1316-1320.)
[4]蔡景治，苑春苗，孟凡一，等.微米和纳米钛粉尘层着火蔓延特性研究［J］.东北大学学报(自然科学版)，2020，41(1):137-142.(Cai Jing-zhi，Yuan Chun-miao，Meng Fan-yi，et al.Study on the fire spread characteristics of micro and nano titanium dust layers［J］.Journal of Northeastern University (Natural Science)，2020，41(1):137-142.)
[5]Manju M.Explosion characteristics of micron- and nano-size magnesium powders［J］.Journal of Loss Prevention in the Process Industries，2014，27:55-64.
[6]Eckhoff R K.Minimum ignition energy (MIE)- a basic ignition sensitivity parameter in design of intrinsically safe electrical apparatus for explosive dust clouds［J］.Journal of Loss Prevention in the Process Industries，2002，15(4):305-310.
[7]Amyotte P.Solid inertants and their use in dust explosion prevention and mitigation［J］.Journal of Loss Prevention in the Process Industries，2006，19(2/3):161-173.
[8]Ma X S，Meng X B，Li Z Y，et al.Study of the influence of melamine polyphosphate and aluminum hydroxide on the flame propagation and explosion overpressure of aluminum magnesium alloy dust［J］.Journal of Loss Prevention in the Process Industries，2020，68:104291.
[9]Wang Z，Meng X B，Yan K，et al.Study on the inhibition of Al-Mg alloy dust explosion by modified Mg(OH)₂［J］.Powder Technology，2021，384:284-296.
[10]Yuan Z，Nima K，Faisal K，et al.Dust explosions:a threat to the process industries［J］.Process Safety and Environmental Protection，2015，98:57-71.
[11]Meng F Y，Hou X C，Amyotte P，et al.Opposite effects of typical solid inertants on flame propagation in Mg dust clouds versus dust layers［J］.Fuel，2022，324:124394.
[12]Meng F Y，Xu S Q，Amyotte P，et al.Characterization of Ti powders mixed with TiO₂ powders:thermal and kinetic studies［J］.Journal of Loss Prevention in the Process Industries，2020，66:104184.
[13]Cai J Z，Li C，Amyotte P，et al.Effect of solid inertants and sample inclination angle on fire hazard of metallic powder layers［J］.Process Safety and Environmental Protection，2019，129:321-325.
[14]Yuan C M，Cai J Z，Amyotte P，et al.Fire hazard of titanium powder layers mixed with inert nano TiO₂ powder［J］.Journal of Hazardous Materials，2018，346:19-26.
[15]Marmo L，Riccio D，Danzi E.Explosibility of metallic waste dusts［J］.Process Safety and Environmental Protection，2017，107:69-80.
[16]Meng F Y，Li C，Amyotte P，et al.Effect of inclination angle on fire hazard of melting dust layers［J］.Process Safety and Environmental Protection，2022，160:620-631.
[17]Kudo Y，Kudo Y，Torikai H，et al.Effects of particle size on flame spread over magnesium powder layer［J］.Fire Safety Journal，2010，45(2):122-128.
[18]Ward T S，Trunov M A，Schoenitz M，et al.Experimental methodology and heat transfer model for identification of ignition kinetics of powdered fuels［J］.International Journal of Heat and Mass Transfer，2006，49(25/26):4943-4954.
[19]Hu F F，Cheng Y F，Zhang B B，et al.Flame propagation and temperature distribution characteristics of magnesium dust clouds inan open space［J］.Powder Technology，2022，404:117513.
[20]Zhou W Y，Lian Q H，Huang X K，et al.Introducing SiC/C dual-interface on porous silicon anode by a conventional exothermic displacement reaction for improved cycle performance［J］.Journal of Power Sources，2021，508:230326.
[21]顾晓然，李顺，唐宇，等.超级铝热剂的发展现状［J］.材料导报，2023(10):1-19.(Gu Xiao-ran，Li Shun，Tang Yu，et al.Development status of super thermite［J］.Materials Reports，2023(10):1-19.)
[22]Delphine M，Romain L，Patrice S.Experimental study and chemical reactor network modeling of the high heating rate devolatilization and oxidation of pulverized bituminous coals under air，oxygen-enriched combustion (OEC) and oxy-fuel combustion (OFC)［J］.Fuel Processing Technology，2018，177:179-193.
[23]李广垠，李志坚，徐娜，等.轻烧氧化镁活性对烧结镁砂性能的影响［J］.硅酸盐通报，2018，37(5):1699-1703.(Li Guang-yin，Li Zhi-jian，Xu Na，et al.Effect of light-burned magnesia activity on properties of sintered magnesia［J］.Bulletin of the Chinese Ceinese Ceramic Society，2018，37(5):1699-1703.