Ignition characteristics of metal dusts generated during machining operations in the presence of calcium carbonate

Nan, Miao; Zhong, Shengjun; Yu, Qingbo

doi:10.1016/j.jlp.2015.12.022

Cited by 29 publications

(4 citation statements)

References 12 publications

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“…With minimum inerting criteria roughly set at MIE > 1000 mJ and MAIT > 450 °C, this study witnessed the effective inerting of Fe alloy and Fe–Al alloy dust using 50% calcium carbonate by mass and the effective inerting of Al alloy dust using 75% calcium carbonate by mass. However, injection of calcium carbonate into pure atomized aluminum, atomized magnesium, or Mg–Al alloy did not demonstrate sufficient increase in MIE or MAIT to qualify successful minimization of ignition risk . Fuels such as aluminum or magnesium are considered highly reactive metals and can be relatively difficult to inert, in contrast to normally reactive metal fuels such as irons or other common alloy metals.…”

Section: Prevention Techniquesmentioning

confidence: 99%

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Metal Dust Explosion Hazards: A Technical Review

Reding

Shiflett

2018

Ind. Eng. Chem. Res.

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Metal dust deflagrations continue to pose a critical threat toward safety in the metal processing industry. This paper begins with introduction of the fundamental requirements for an explosion and reviews the modern developments in explosion prevention techniques, while describing the challenges confronted with applying these techniques to nonstandard metal dust applications. Variability in several intrinsic properties associated with bulk solids conveyance (such as propagation behavior, degree of turbulence, particle size, and moisture content) contributes to metallic fuels having the increased potential to act as highly reactive explosion hazards. Upon ignition in a contained enclosure volume and propagation to interconnected vessels, metal dusts exhibit augmented explosion severity and sensitivity because of their large heats of combustion, higher burning temperatures, radiative heat transfer effects, and abnormally reactive interactions with water. These characteristics are specific to metal dust fuels and are not commonly demonstrated in organic combustion.

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Section: Prevention Techniquesmentioning

confidence: 99%

“…11 Fuels such as aluminum or magnesium are considered highly reactive metals and can be relatively difficult to inert, in contrast to normally reactive metal fuels such as irons or other common alloy metals.…”

mentioning

confidence: 99%

Metal Dust Explosion Hazards: A Technical Review

Reding

Shiflett

2018

Ind. Eng. Chem. Res.

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“…The experimental results indicate that the explosiveness of micrometer-scale titanium powder is far inferior to that of nanometer-scale titanium powder. Miao et al studied the ignition probability of various metal powders under the inertion action of CaCO 3 powder and found that CaCO 3 has an inhibitory effect on all metal powders, and the ignition success rate is reduced. Wang et al , investigated the explosion characteristics of Al–Mg alloy particles with different particle sizes and concentrations, while using modified Mg (OH) 2 as an explosion suppressant.…”

Section: Introductionmentioning

confidence: 99%

Research on the Inhibition Effect of NaCl on the Explosion of Mg–Al Alloy Powder

Qin,

Wei,

Shi

et al. 2024

ACS Omega

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A study was conducted on the explosion overpressure and flame propagation law of magnesium−aluminum (Mg−Al) alloy powder, and the suppression mechanism of sodium chloride (NaCl) on the explosion of magnesium−aluminum alloy powder was explored. Adding NaCl powder can effectively reduce the explosion pressure, flame front position, and flame propagation speed. The higher the amount of NaCl powder added, the lower the explosion pressure of magnesium−aluminum alloy powder, the slower the flame propagation speed, and the lower the flame brightness. NaCl adsorbed on Mg−Al alloy powder isolated heat transfer and played a cooling role. The Cl − produced by NaCl decomposition will react with the free radicals H + and OH − in the reaction system, which will reduce the concentration of H + and OH − in the combustion process and hinder the propagation and expansion of the flame. The research results provide theoretical guidance for the explosion prevention of Mg−Al alloy powder and the preparation of a physical−chemical compound explosion suppressor in the later stage.

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“…In this paper, components of the powder system are magnesium hydroxide, sodium bicarbonate and calcium carbonate. The last two compounds are commonly used in the extinguishing powders [ 22 , 23 , 24 , 25 , 26 , 27 ], but there is a lack of information about their mutual influence on the extinguishing effect. Hence, studies on the determination of the effect of magnesium hydroxide at the expense of sodium bicarbonate on both the fire extinguishing efficiency and the mechanism of action are justified.…”

Section: Introductionmentioning

confidence: 99%

The Effect of Magnesium Hydroxide Addition on the Extinguishing Efficiency of Sodium Bicarbonate Powders

et al. 2022

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This article analyzes the possibility of the modification of BC powder (a mixture of sodium bicarbonate and calcium carbonate) with magnesium hydroxide (Mg(OH)2). Extinguishing efficiency as well as the influence of this additive on other physicochemical properties were determined by performing a 13B fire test, rheological measurements of the powders, thermal tests (thermogravimetry (TG) and differential scanning calorimetry (DSC) in combination with quadrupole mass spectrometry (QMS)) and microscopic observations of the powders’ surface (scanning electron microscope (SEM) with energy dispersive X-ray analysis (EDS)). It was found that the increase of the Mg(OH)2 content causes deterioration of the rheological properties by increasing the slope angle of the flow curve in relation to the normal stress (the tangent of the flow curve slope varying from 0.258 for 5% of Mg(OH)2 up to 0.330 for 20% of Mg(OH)2). However, at the same time, the increased content of Mg(OH)2 increases the total energy of the chemical decomposition reaction (from −47.27 J/g for 5% of Mg(OH)2 up to −213.6 J/g for 20% of Mg(OH)2) resulting in the desirable higher level of heat removal from the fire. The initial extinguishing effect of the fire becomes more effective as the hydroxide content increases (within the first 2 s), but at a later stage (from t = 63 s), the temperature is no longer sufficient (it is below 350 °C) for thermal decomposition of Mg(OH)2. As such, the optimal content of Mg(OH)2 is 10–15%. The obtained results allowed for the assessment of the impact of individual powder components on its extinguishing effect and will contribute to the development of science in the field of developing new types of extinguishing powders.

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Ignition characteristics of metal dusts generated during machining operations in the presence of calcium carbonate

Abstract: Ignition characteristics of metal dusts generated during machining operations in the presence of calcium carbonate

Cited by 29 publications

References 12 publications

Metal Dust Explosion Hazards: A Technical Review

Metal Dust Explosion Hazards: A Technical Review

Research on the Inhibition Effect of NaCl on the Explosion of Mg–Al Alloy Powder

The Effect of Magnesium Hydroxide Addition on the Extinguishing Efficiency of Sodium Bicarbonate Powders

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