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Characterization of a spark discharge for dust cloud ignition
Author(s) -
Sankhé Mamadou,
Bernard Stéphane,
Wartel Maxime,
Pellerin Stéphane,
Gillard Philippe
Publication year - 2019
Publication title -
contributions to plasma physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.531
H-Index - 47
eISSN - 1521-3986
pISSN - 0863-1042
DOI - 10.1002/ctpp.201800090
Subject(s) - plasma , materials science , atomic physics , ionization , ignition system , spark gap , tungsten , excitation temperature , electron temperature , excitation , physics , mechanics , computational physics , emission spectrum , electrode , ion , thermodynamics , spectral line , quantum mechanics , astronomy , metallurgy
Spark discharges are widely used to ignite flammable gases, liquids, or dust. For a better understanding of the interaction between the spark discharge and the ignited media (gas, liquid, or dust), it is necessary to measure some key parameters of the spark, especially the space‐time variation of its temperature. Determination of temperature gradients would allow a more precise and realistic simulation of the ignition process. In fact, electrons and particles in the discharge zone get their energy with increasing temperature before interacting with particles of the media to ignite the flame. In this study, optical emission spectroscopy of the spark discharge between two tungsten electrodes was performed. Assuming excitation balance between the WI lines, a Boltzmann plot after an Abel inversion gives the excitation temperature and its space‐time variation. For a 100‐μs time discharge, at 80‐μs delay, we measured 7,000 K at the centre of the column zone, 4,100 K at the centre of the cathode zone, and 3,600 K at the centre of the anode zone. Assuming a singly ionized tungsten plasma and excitation equilibrium, we used also the Saha–Boltzmann equation to calculate the plasma composition. The electron density at the column zone was about 3 × 10 17 cm −3 , which is two orders of magnitude higher than in the rest of the spark.