‘Knock on nanocellulose’: Approaching the laminar burning velocity of powder-air flames

Santandréa, Audrey; Gavard, Marine; Pacault, Stéphanie; Vignes, Alexis; Praly, Laurent; Dufaud, Olivier

doi:10.1016/j.psep.2019.12.018

Cited by 13 publications

(12 citation statements)

References 66 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…by sedimentation, agglomerates ranging from a few micrometers up to 60 µm are formed in the powder. This does not exclude the presence of nanoparticles (from 100 nm to 300 nm) in the dust cloud as demonstrated by using a Fast Mobility Particle Sizer (FMPS) and a Scanning Mobility (Santandrea et al, 2020).…”

Section: Flame Propagation Observationmentioning

confidence: 99%

“…Nanocellulose powder, or more precisely a cellulose nanocrystals powder NCC (CelluForce), is composed of primary fibers, whose dimensions are 70 nm length and 3 nm width. The flame propagation of nanocellulose was studied at low turbulence by Santandrea et al (2020) in a flame propagation tube (Cuervo et al, 2017) and in a vented visualization 20 L sphere, as summarized in Figure 1. Due to a difficult visualization of the flame kernel at high concentration, a concentration of ensure an ignition at low ignition energy.…”

Section: Flame Propagation Observationmentioning

confidence: 99%

“…Figure 1. Simplified scheme of the experimental determination of the laminar burning velocity by flame visualization used by Santandrea et al (2020) Explosion were recorded using a high-speed video camera, and the flame kernel growth was analysed in terms of flame front position and surface area using a model developed by Cuervo (2015) in…”

Section: Flame Propagation Observationmentioning

confidence: 99%

“…The existence of a laminar burning velocity of dusts is difficult to define due to the inherent turbulence related to the dispersion of the powder but such an approach was already proposed 30 years ago by Bradley and Lee (1984), though it proved itself challenging when it comes to dusts. Nevertheless, the low inertia and sedimentation rate of nanoparticles enable to investigate flame propagation in very low turbulent conditions (Santandrea et al, 2020).…”

Section: Introductionmentioning

confidence: 99%

“…In this paper, a one-dimensional model initially conceived and validated for hybrid mixtures of gas and combustible dust (Torrado et al, 2018) has been modified and adapted to predict the laminar flame velocity of nanocellulose. Results of simulations are then compared to the experimental values measured on nanocellulose using a flame propagation tube and a vented explosion sphere (Santandrea et al, 2020). The consistency of a correlation established by Silvestrini et al (2008) to predict laminar flame velocity of micropowders based on the knowledge of their explosion severity was also analyzed for nanocellulose.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

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

Self Cite

View full text Add to dashboard Cite

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.

show abstract

Section: Flame Propagation Observationmentioning

confidence: 99%

Section: Flame Propagation Observationmentioning

confidence: 99%

Section: Flame Propagation Observationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

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

Self Cite

View full text Add to dashboard Cite

show abstract

Decoupling pyrolysis and combustion of organic powders to determine the laminar flame speed

Pietraccini,

Santandrea,

Glaude

et al. 2024

Can J Chem Eng

View full text Add to dashboard Cite

Determining the laminar flame speed of dusts is far from straightforward. A strong dependency on the experimental setup and the data treatment's high complexity makes it a true challenge. This work compares three complementary experimental setups to measure the laminar flame speed of organic dust (here, cellulose): a modified Hartmann tube, a 20 L sphere, and a micro‐fluidized bed (MFB) burner. The first two consider the flame propagation phenomenon in its globality, which means that numerous steps are involved simultaneously (particle heating, pyrolysis, oxidation, radiative transfer, flame stretching), while the third one decouples pyrolysis and combustion, to focus mainly on the oxidation rate. An MFB was conceived to generate pyrolysis products and burn them in a laminar flame. Unstretched flame velocities determined with the first two setups were consistent and equal to 22.0 and 26.6 cm ∙ s−1, respectively. Using Silvestrini's equation, values ranging between 14.0 and 33.4 cm ∙ s−1 were obtained according to the dust concentration. With the MFB burner, the flame speed was much higher (135–155 cm ∙ s−1), due to the higher temperature of the fresh mixture and the fact that only the oxidation of the pyrolysis gases is considered. A numerical simulation (Chemkin) confirmed these results since the range 135 to 231 cm ∙ s−1 was obtained for equivalence ratios of 0.6 and 1.2, respectively. The discrepancy between the laminar flame speed determined in the sphere or in the tube and that obtained in the MFB highlights the significant influence of particle heating and pyrolysis during a dust explosion.

show abstract