Measurement of Minimum Ignition Energy by Electrostatic Discharge for Flammable Ternary Gas Mixtures

In industrial sectors that use, process, transport or store, substances such as combustible dusts could exist some workplaces with explosion hazard due to the possibility of dust/air explosive formation and ignition, both inside the installations and in the surrounding atmosphere. Methods and means of protection aim to prevent the development of explosive atmospheres, followed by preventing the occurrence of ignition sources and then limiting the effects of explosions. To assess the risk of ignition of the explosive atmosphere, there must be known first of all, the explosive atmosphere’s sensitivity to ignition by electrostatic discharge, respectively, the minimum ignition energy of the explosive mixture, afterwards being required an analysis on the possibilities of formation and discharge of electrostatic charge. For the most common combustible dusts, the minimum ignition energy is given, but for new types of flammable substances this parameter defining the sensitivity to ignition of the mixture by electrostatic discharges must be determined. The paper presents the results of research carried out in order to develop the methods and standards for determining the minimum ignition energy of the combustible dust / air mixture and of the methods for the assessment of the risk of ignition of the dust/air explosive atmosphere by electrostatic discharge.

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Aspects of laboratory tests for the determination of the minimum ignition energy of the fuel / dust mixture

MATEC Web of Conferences ◽

10.1051/matecconf/202134204004 ◽

2021 ◽

Vol 342 ◽

pp. 04004

Author(s):

Cătălin Mihai Popa ◽

Silviu Marin Nan ◽

Mihaela Părăian ◽

Adrian Jurca ◽

Florin Păun

Keyword(s):

Laboratory Tests ◽

Electrostatic Discharge ◽

Explosive Mixture ◽

Ignition Energy ◽

Minimum Ignition Energy ◽

Electrostatic Discharges ◽

Explosive Force ◽

And Storage ◽

Existing Data

During the technological processes of processing, production, handling and storage of combustible dusts, complex explosive mixtures may occur, the characteristics of which, in most cases, cannot be assimilated with the existing data in the specialized literature. If these combustible dusts are mixed with air in appropriate proportions and are initiated by an efficient source of ignition, they can burn rapidly and with considerable explosive force. One of the most common sources of ignition of potentially explosive atmospheres generated by the dust / air mixture is static electricity, materialized by electrostatic discharges. In order to assess the risk of ignition of an explosive mixture of air / dust, it is necessary to know the sensitivity of the explosive atmosphere to ignition, ie the value of the minimum ignition energy of the explosive mixture, which is then compared with the energy resulting from an electrostatic discharge. The paper presents a comparative analysis regarding the methods of determining the minimum ignition energy for air / fuel dust mixtures, using different devices, on the same type of dust.

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Potentially explosive atmospheres. Explosion prevention and protection. Determination of minimum ignition energy of dust/air mixtures

10.3403/02704478 ◽

2002 ◽

Cited By ~ 1

Keyword(s):

Ignition Energy ◽

Minimum Ignition Energy

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A Numerical Study on the Effect of the Equivalence Ratio of Hydrogen/Air or Methane/Air Mixtures on Minimum Ignition Energy in Spark Ignition Process

TRANSACTIONS OF THE JAPAN SOCIETY OF MECHANICAL ENGINEERS Series B ◽

10.1299/kikaib.72.818 ◽

2006 ◽

Vol 72 (715) ◽

pp. 818-824 ◽

Cited By ~ 2

Author(s):

Shinji NAKAYA ◽

Kazuo HATORI ◽

Mitsuhiro TSUE ◽

Michikata KONO ◽

Daisuke SEGAWA ◽

...

Keyword(s):

Equivalence Ratio ◽

Numerical Study ◽

Spark Ignition ◽

Ignition Process ◽

Ignition Energy ◽

Minimum Ignition Energy

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Ignition and flame quenching of quiescent fuel mists

Proceedings of the Royal Society of London Series A - Mathematical and Physical Sciences ◽

10.1098/rspa.1978.0201 ◽

1978 ◽

Vol 364 (1717) ◽

pp. 277-294 ◽

Cited By ~ 41

Keyword(s):

Reaction Rates ◽

Ignition Energy ◽

Minimum Ignition Energy ◽

Proposed Model ◽

Theoretical Predictions ◽

Quenching Distance ◽

Experimental Values ◽

Sole Criterion ◽

Fuel Vapour ◽

Level Of Agreement

A model is proposed for the ignition of quiescent multidroplet fuel mists which assumes that chemical reaction rates are infinitely fast, and that the sole criterion for successful ignition is the generation, by the spark, of an adequate concentration of fuel vapour in the ignition zone. From analysis of the relevant heat transfer and evaporation processes involved, expressions are derived for the prediction of quenching distance and minimum ignition energy. Support for the model is demonstrated by a close level of agreement between theoretical predictions of minimum ignition energy and the corresponding experimental values obtained using a specially designed ignition apparatus in which ignition energies are measured for several different fuels, over wide ranges of pressure, mixture composition and mean drop size. The results show that both quenching distance and minimum ignition energy are strongly dependent on droplet size, and are also dependent, but to a lesser extent, on air density, equivalence ratio and fuel volatility. An expression is derived to indicate the range of drop sizes over which the proposed model is valid.

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