| Zugriffsnummer | 21871 |
| Dokumenttyp | Konferenzartikel |
| Sprache | Englisch |
| Titel | Experimental simulation of an atmospheric deflagration for the testing of end-of-line flame arresters |
| Autor(in); Institution |
Mecke, Stefan; 3.5, Zünddurchschlagsprozesse, PTB-Braunschweig
Markus, Detlef; 3.5, Zünddurchschlagsprozesse, PTB-Braunschweig
Förster, Hans; 3.4, Grundlagen des Explosionsschutzes, PTB-Braunschweig
|
| Quelle/Jahr | Seventh ISHPMIE proceedings : Seventh International Symposium on Hazards, Prevention, and Mitigation of Industrial Explosions. Vol. 3:(2008), 295 - 304 |
| Verlag | St. Petersburg: |
| Konferenzangaben | 7th International Symposium on Hazards, Prevention, and Mitigation of Industrial Explosions, St. Petersburg, 07-11, July, 2008, Russia |
| Freie Schlagworte | Flame arresters ; Flame Transmission ; Quenching |
| Zusammenfassung | In concepts for industrial explosion protection the occurrence of an accidental explosion has to be taken into account. In this case a reasonable protection often can be assured by limiting the propagation of the anticipated explosion by the use of flame arresters. One example of a flame arrester is the so called end-of-line flame arrester. It is used to protect the inner part of an apparatus or a fuel tank from an external explosion. This atmospheric deflagration propagates in a vapour-air cloud for which neither the size nor the concentration gradient are predictable. For the certification of end-of-line flame arresters it is essential to simulate such atmospheric deflagrations with a manageable testing setup. This paper analyses accident reports as well as theoretical estimations of the pressure generation in unconfined vapour cloud explosions to investigate the dynamic load of an end-of-line flame arrester. On the basic of this results the testing setup of the current standardisation for flame arresters (EN 12874) which is using a plastic bag filled with a characteristic gas-air mixture to simulate the unconfined vapour cloud explosion is investigated concerning its suitability for the testing procedure. The flame propagation in this testing facility is examined using a high speed camera and pressure recording. This analysis reveals shortcomings of the setup concerning the dynamic loads and the repeatability of the testing procedure. Additionally it is shown that the manageability of the setup is insufficient. Furthermore an upcoming change in standardisation from EN 12874 to ISO 16852 will lead to the requirement that the flame transmission test shall be realisable using atmospheric pressure for flame arrester elements of the measurable type as well as using a higher pressure for elements of the non-measurable type which is not realisable with the existing setup. In this work a new testing facility for flame arresters that are used and tested under atmospheric conditions is presented. The setup replaces the plastic bag by a short, vertically fixed tube made of plexiglass. The tube has an opening at its top which can be narrowed by an aperture to increase the flow resistance, which leads to an increase of the pressure of an internal explosion. Additionally the flame propagation and the pressure history can be investigated. The paper presents a safety-related analysis of the protective system “end-of-line flame arrester” which leads to the introduction of a new testing setup that offers a better experimental simulation of an unconfined vapour cloud explosion, a better repeatability of the tests and an improved manageability of the setup. |
Zitierung
Mecke, S., Markus, D., & Förster, H. (2008). Experimental simulation of an atmospheric deflagration for the testing of end-of-line flame arresters. 7th International Symposium on Hazards, Prevention, and Mitigation of Industrial Explosions, St. Petersburg, 07-11, July, 2008, Russia.