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Title: Funkenzündung von Gasgemischen bei erhöhten Drücken und Temperaturen für die Zündschutzart Eigensicherheit
Editor: Physikalisch-Technische Bundesanstalt
Report type: PTB-Report
Year: 2002
Document number: PTB-ThEx-23
Pages: VII, 106
ISBN: ISBN 3-89701-834-9 ; ISSN 1434-2391
Abstract: The thesis "Spark ignition of gas mixtures at increased pressures and temperatures for the type of protection Intrinsic Safety" deals with the influence of an increased pressure or an increased temperature of the mixture on the different ignition processes necessary for maintaining an explosion protection measure taken according to the type of protection Intrinsic Safety. These ignition processes relate both to the ignition of an electrical spark in the current and voltage range typical of the type of protection Intrinsic Safety and to the ignition of an explosive fuel-gas/air mixture potentially following. As fuel gases, hydrogen and ethylene are used. In addition to the standardized spark test apparatus for recording minimum ignition curves, a novel spark observation device was available, which allows spark discharges and mixture ignitions to be made visible with the aid of a CCD camera and schlieren optics. This work will first give a detailed description of the test set-up and the performance of the tests using the spark test apparatus to ensure reproduction of the obtained results also by other test centres. The minimum ignition curves determined form the basis for the testing and certification of intrinsically safe explosion-proof electrical equipment. The applicability of the standardized spark test apparatus of the minimum ignition curves measured with it in the investigated pressure and temperature range up to 0.5 MPa and 100 .deg.C is demonstrated. In fundamental investigations, the dependencies of the different ignition parameters on the parameters pressure, temperature and electrical power are ascertained and explained. New findings as regards the formation of explosion ignitions are obtained by comparison of the measurements of the spark duration carried out with the spark test apparatus and the spark observation device, and the energy available in the spark.
Note: Funkenzündung von Gasgemischen bei erhöhten Drücken und Temperaturen für die Zündschutzart Eigensicherheit ; (PTB-Bericht PTB-ThEx-23) ; Zugl.: Braunschweig, Techn. Univ., Diss.

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