Comparing Pyrolysis Gases and Dusts Explosivities: A Clue to Understanding Hybrid Mixtures Explosions?

Dufaud, Olivier; Poupeau, Manon; Khalili, Imad; Cuervo, Nicolás; Christodoulou, Mélina; Olcese, Roberto N.; Dufour, Anthony; Praly, Laurent

doi:10.1021/ie201646s

Cited by 25 publications

(3 citation statements)

References 30 publications

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“…Dufaud et al 88) comment on how better knowledge of hybrid explosion behavior is used to modify an important industrial norm (NFPA 68; venting of deflagrations). Dufaud et al 89) study effects of pyrolysis gases/vapors evolving during dust explosions of organic powders and develop a predictive model. Garcia-Agreda et al 90) develop an insightful way of graphically presenting hybrid explosion behavior in terms of measured K St values and 5 combustion regimes: non-explosive, dustdriven, gas/vapour-driven, gas-gas/vapour-driven, and 'synergistically' driven.…”

Section: Hybrid Mixturesmentioning

confidence: 99%

A Review of the Fire and Explosion Hazards of Particulates

Lemkowitz

Pasman

2014

KONA

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Particulate fires and explosions cause substantial loss of life and property. With the goal of understanding, preventing, or at least mitigating particulate fire and explosion hazards, we review basics. We distinguish between 'hazard' and 'risk' and discuss the fire and explosion hazards of particulates, the many factors determining such hazards, hazard indexes, and ways to reduce fire and explosion hazards. While our primary goal is to improve safety, we briefly discuss how fundamental knowledge can be extracted from weapon technology based on particulate combustion. We review the prevention of and protection against particulate explosions and discuss ongoing and future research.

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Section: Hybrid Mixturesmentioning

confidence: 99%

A Review of the Fire and Explosion Hazards of Particulates

Lemkowitz

Pasman

2014

KONA

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“…For the wheat starch material, the drag coefficient (

C_{D}

) was calculated based on Haider & Levenspiel model (1989), for non‐spherical particles . The above proposed correlation depends on the shape factor of the wheat starch (Eqs.…”

Section: Methodsmentioning

confidence: 99%

CFD as an approach to understand flammable dust 20 L standard test: Effect of the ignition time on the fluid flow

et al. 2017

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in Wiley Online Library (wileyonlinelibrary.com)A computational study based on the Euler-Lagrange approach was developed for the characterization of flammable dusts in the 20 L sphere standard test. The aim of the study was to analyze some parameters that might affect the experimental data (e.g., cold turbulence and particle size). The turbulence of a wheat starch cloud was described with the Detached Eddy Simulation model. Both the pressure of the system and the RMS velocity were compared with the flow patterns established with a particle image velocimetry analysis. It was concluded that the rebound nozzle forms a cloud that is composed by clumps. This fact implies dissimilarities between the local concentrations and the nominal value. Finally, a granulometric analysis established that the mean diameter of the particle size distribution (PSD) decreased by 69% during the dispersion. Thus, it is suggested to consider the PSD at the ignition zone rather than the PSD of the sample. V C 2017 American Institute of Chemical Engineers AIChE J, 64: 42-54, 2018

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“…Pyrolysis experiments were conducted on wheat starch (d50 = 22 µm) in a Godbert-Greenwald oven modified according to Dufaud et al (2012b) to collect the post-pyrolysis gases. Oven temperature was modified over a range of 973 to 1173 K. It should be noted that the minimum ignition temperature (MIT) of cellulose powder is approximately 773K, value depending on the particle size distribution.…”

Section: One-dimensional Modelling Of Flame Propagationmentioning

confidence: 99%

Fast and tiny: A model for the flame propagation of nanopowders

Santandréa¹,

Torrado²,

Pietraccini³

et al. 2021

Journal of Loss Prevention in the Process Industries

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To avoid the influence of external parameters, such as the vessel volume or the initial turbulence, the explosion severity should be determined from intrinsic properties of the fuel-air mixture. Therefore, the flame propagation of gaseous mixtures is often studied in order to estimate their laminar burning velocity, which is both independent of external factors and a useful input for CFD simulation.Experimentally, this parameter is difficult to evaluate when it comes to dust explosion, due to the inherent turbulence during the dispersion of the cloud. However, the low inertia of nanoparticles allows performing tests at very low turbulence without sedimentation. Knowledge on flame propagation concerning nanoparticles may then be modelled and, under certain conditions, extrapolated to microparticles, for which an experimental measurement is a delicate task. This work focuses on a nanocellulose with primary fiber dimensions of 3 nm width and 70 nm length. A onedimensional model was developed to estimate the flame velocity of a nanocellulose explosion, based on an existing model already validated for hybrid mixtures of gas and carbonaceous nanopowders similar to soot. Assuming the fast devolatilization of organic nanopowders, the chemical reactions considered are limited to the combustion of the pyrolysis gases. The finite volume method was used to solve the mass and energy balances equations and mass reactions rates constituting the numerical system. Finally, the radiative heat transfer was also considered, highlighting the influence of the total surface area of the particles on the thermal radiation. Flame velocities of nanocellulose from 17.5 to 20.8 cm/s were obtained numerically depending on the radiative heat transfer, which proves a good agreement with the values around 21 cm/s measured experimentally by flame visualization and allows the validation of the model for nanoparticles.

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Comparing Pyrolysis Gases and Dusts Explosivities: A Clue to Understanding Hybrid Mixtures Explosions?

Cited by 25 publications

References 30 publications

A Review of the Fire and Explosion Hazards of Particulates

A Review of the Fire and Explosion Hazards of Particulates

CFD as an approach to understand flammable dust 20 L standard test: Effect of the ignition time on the fluid flow

Fast and tiny: A model for the flame propagation of nanopowders

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