TY - CONF A1 - Askar, Enis T1 - Sicherheitstechnische Fragestellungen im Zusammenhang mit Elektrolyseanlagen N2 - Im Vortrag werden aktuelle Entwicklungen bei verschiedenen Elektrolysetechnologien kurz vorgestellt. Dann werden für Elektrolyseanlagen spezifische Gefährdungen diskutiert, v.a. die im Zusammenhang mit den Eigenschaften der Gase Wasserstoff und Sauerstoff stehen. Dabei wird auch Bezug auf die Normung- und Regelsetzung genommen und Sicherheitskonzepte werden beispielhaft kurz vorgestellt. Abschließend wird auf Unfallereignisse im Zusammenhang mit der Elektrolyse eingegangen. T2 - BAM/UBA-Behördenerfahrungsaustausch CY - Berlin, Germany DA - 27.06.2022 KW - Explosionsschutz KW - Wasserstofferzeugung KW - Sauerstoff KW - Sicherheit PY - 2022 AN - OPUS4-55220 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Askar, Enis A1 - Grunewald, Thomas T1 - Experimentelle Untersuchung von Zündwahrscheinlichkeiten bei mechanischen Schlagvorgängen in wasserstoffhaltigen Atmosphären N2 - Im Projekt HySpark wird die Wirksamkeit mechanischer Schlagvorgänge beim Aufprall von unterschiedlichen Werkstoffen als Zündquelle für wasserstoffhaltige Atmosphären experimentell untersucht. Zum Einen wird die Zündwirksamkeit bei Wasserstoff/Luft-Gemischen in Abhängigkeit der Werkstoffpaarung untersucht. Dabei konnte v.a. festgestellt werden, dass bei Schlagvorgängen von Nicht-Eisen-Metallen mit verschiedenen Stahlsorten die wirksame Zündung vermieden werden kann. Jedoch können bei Schlagvorgängen mit Estrichbeton hohe Zündwahrscheinlichkeiten beobachtet werden. Zum anderen wird der Einfluss von Wasserstoffbeimischungen im Erdgasnetz auf die Zündwirksamkeit von mechanischen Schlägen untersucht. Bei Anteilen bis 25% Wasserstoff konnte bei den Versuchen kein Erhöhung der Zündwahrscheinlichkeit festgestellt werden. T2 - H2-Kolloquium des Kompetenzzentrums „H2Safety@BAM” CY - Online meeting DA - 04.07.2022 KW - Explosionsschutz KW - Zündquellen KW - Schlagfunken KW - Erdgas PY - 2022 AN - OPUS4-55224 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Spitzer, Stefan A1 - Askar, Enis A1 - Benke, Alexander A1 - Cloney, C. A1 - D’Hyon, S. A1 - Dufaud, O. A1 - Dyduch, Z. A1 - Gabel, D. A1 - Geoerg, P. A1 - Heilmann, V. A1 - Jankuj, V. A1 - Jian, W. A1 - Krause, U. A1 - Krietsch, Arne A1 - Mynarz, M. A1 - Norman, F. A1 - Skrinsky, J. A1 - Taveau, J. A1 - Vignes, A. A1 - Zakel, S. A1 - Zhong, S. T1 - 1st international round robin test on safety characteristics of hybrid mixtures JF - Journal of loss prevention in the process industries N2 - There is no applicable existing standard for the determination of safety characteristics for hybrid mixtures. While developing a new standard in a joint research project in Germany first results from parameter studies led to a standard procedure that can be adopted by laboratories that are already testing dusts in the so called 20L-sphere with as little additional effort as necessary. In fact, one of the main objectives of this research project was to keep modifications and adjustments from the generally accepted dust testing procedures as easy and minimal as possible so as to limit potential deviations from one laboratory to another. In this first round robin test on hybrid mixtures ever, with methane as gas component and a specific corn starch as dust sample, the practicality of the whole procedure, the scattering of the results and the deviation between the testing apparatuses is investigated. This paper summarizes the experimental procedure adopted and objectives of the first round-robin phase involving three of the four original German companies, plus volunteering laboratories from Australia, Belgium, Czech Republic, France, Poland and P.R. China. The results will have an impact on the new standard and may lead to robust data for later simulation purposes. KW - Hybrid mixtures KW - 20L-sphere KW - Round robin test KW - Turbulent combustion PY - 2022 DO - https://doi.org/10.1016/j.jlp.2022.104947 SN - 0950-4230 VL - 81 SP - 1 EP - 8 PB - Elsevier CY - Amsterdam AN - OPUS4-56516 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Askar, Enis T1 - Hydrogen Safety - Explosion Protection for Hydrogen Applications N2 - In this lecture the safety related properties og hydrogen compared to other fuel gases and the explosion protection measures of avoiding flammable mixtures, avoiding ignition sources and mitigating the consequences of explosions when handling hydrogen and hydrogen mixtures are presented. The Joint European Summer School JESS 2021 addresses these issues by offering high quality graduate level courses on selected topics of vehicle technology, innovation & business development, safe handling of hydrogen, and modelling. The course content is tailored to the needs of a diverse audience: newcomers to the field, experienced students, and young professionals working at the forefront of fuel cell and hydrogen applications. T2 - Joint European Summer School (JESS) CY - Online meeting DA - 06.09.2021 KW - Explosionsschutz KW - Explosionsgrenzen KW - Zündenergie KW - Zündquellen KW - Auswirkung von Explosionen PY - 2021 AN - OPUS4-53808 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Askar, Enis A1 - Holtappels, Kai T1 - Fire and explosion safety for hydrogen technologies N2 - The presentation gives an overview about the research and testing activities of H2Safety@bam in the field of process and plant safety. T2 - HYDROGENIUS BAM Joint Hydrogen Symposium CY - Online meeting DA - 06.07.2021 KW - Explosion protection KW - LH2 KW - Jet-fires KW - Test area PY - 2021 AN - OPUS4-53720 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Askar, Enis T1 - Sicherheitstechnische Eigenschaften von Erdgas/Wasserstoff-Gemischen - Auswirkungen auf den Explosionsschutz N2 - Hinsichtlich ihrer sicherheitstechnischen Kenngrößen (STK) unterscheiden sich Wasserstoff und Erdgas zum Teil stark. Im Vortrag werden verschiedene STK von Erdgas/Wasserstoff-Gemischen im Abhängigkeit des Wasserstoffanteils vorgestellt und die Auswirkung der Beimischung von Wasserstoff zum Erdgas auf die Wirksamkeit von Explosionsschutzmaßnahmen erläutert. T2 - DVGW-Kongress 2021 "Gasinfrastruktur für Erdgas-H2-Gemische" CY - Online meeting DA - 07.10.2021 KW - Explosionsschutz KW - Explosionsgrenzen KW - Zündenergie KW - Power to Gas KW - Erdgasnetz KW - Zündquellen PY - 2021 AN - OPUS4-53725 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Spitzer, Stefan A1 - Askar, Enis A1 - Benke, Alexander A1 - Janovsky, B. A1 - Krause, U. A1 - Krietsch, Arne T1 - Influence of pre-ignition pressure rise on safety characteristics of dusts and hybrid mixtures JF - Fuel N2 - For the determination of the safety characteristics of dusts it is necessary to disperse the dust in the oxidating atmosphere (usually air). In the standard procedures for dusts this is realized by a partially evacuated explosion vessel (20L-sphere) in which the dust gets injected from a dust chamber pressurized with air. Shortly after that injection (60 ms) the dust cloud gets ignited under turbulent conditions, that are otherwise seen as almost ambient with 20 ◦C and about 1 bar (abs). While there has been a lot of research about the influence of the ignition delay time and the level of turbulence in the recent years little attention was paid to the pre–ignition pressure rise and the allowed variations in the standards. In the following work we showed that the allowed ranges for the pressures in the different dust standards influence the safety characteristics of dust alone severely. Even though hybrid mixtures are an emerging risk problem in an interconnected industry there is no standard for the determination of their safety characteristics. In this work it is shown that especially for the preparation of hybrid mixtures of flammable dust and gas the pressures after injection of the dust and the mixing procedure have a large influence on the composition of the tested mixtures and therefore on the safety characteristics. Considering both effects, wrong concentration of gas and wrong initial pressure, the discrepancy of safety characteristics from different facilities will be too big to applicable. The methods to overcome these weaknesses are also presented. KW - Hybrid mixtures KW - 20L-sphere KW - Pre-ignition pressure rise KW - Post-injection pressure drop KW - Safety characteristics KW - Mixing procedure PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-537358 DO - https://doi.org/10.1016/j.fuel.2021.122495 VL - 311 SP - 122495 PB - Elsevier Ltd. CY - Niederlande AN - OPUS4-53735 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Spitzer, Stefan A1 - Askar, Enis A1 - Krietsch, Arne A1 - Schröder, Volkmar T1 - Comparative study on standardized ignition sources used for explosion testing JF - Journal of loss prevention in the process industries N2 - For the determination of safety characteristics of gases, vapors and dusts different types of ignition sources are used in international standards and guidelines. The paper presents test results of a comparative calorimetric and visual study between four different types of ignition sources. The ignition procedures were analyzed visually with a high-speed camera and electric recordings. In addition to that, the influence of the electrode-orientation, -distance as well as ignition energy on the reproducibility of the exploding wire igniter was tested. The exploding wire is already in use for standardized determination of safety characteristics of gases, first tests on the suitability of the exploding wire igniter for dust testing have been carried out but are not standardized yet. Using the exploding wire, the ignition energy can be varied from 2 J to 10 000 J (2 x 5000 J) and thus it could be used for gases, vapors, dusts and hybrid mixtures. Moreover it can be used at high initial pressures and it is the only ignition source with an easily measurable ignition energy release. Furthermore, it does not introduce another chemical reaction into the system. Finally, a proposal for a standard ignition source for explosion tests on hybrid mixtures is derived from the test results. T2 - 13th International Symposium on Hazards, Prevention, and Mitigation of Industrial Explosions CY - Braunschweig, Germany DA - 27.07.2020 KW - Ignition source KW - Exploding wire KW - Hybrid mixtures KW - Safety characteristics determination PY - 2021 DO - https://doi.org/10.1016/j.jlp.2021.104516 SN - 0950-4230 VL - 71 IS - July SP - 1 EP - 15 PB - Elsevier CY - Amsterdam AN - OPUS4-52548 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Abdelkhalik, A. A1 - Askar, Enis A1 - Markus, D. A1 - Stolz, T. A1 - Brandes, E. A1 - Zakel, S. T1 - Explosion regions of 1,3-dioxolane/nitrous oxide and 1,3-dioxolane/air with different inert gases - Experimental data and numerical modelling JF - Journal of Loss Prevention in the Process Industries N2 - In this study, experimental determination and modelling investigations for the explosion regions of 1,3-dioxolane/inert gas/N2O and 1,3-dioxolane/inert gas/air mixtures were carried out and compared. The experimental measurements were carried out at 338 K and atmospheric pressure according to EN1839 method T using the inert gases N2, CO2, He and Ar. The results showed that the ratio of the lower explosion limit in N2O (LELN2O) to the lower explosion limit in air (LELair) is 0.52 and the ratio of the maximum oxygen content in air (MOCair) to the limiting oxidizer fraction in nitrous oxide (LOFN2O) is 0.36 ± 0.02 independent of the inert gas. When comparing the inert gas amount at the apex based on the pure oxidizing component, which is O2 in case of air, N2O-containing mixtures need less inert gas to reach the limiting oxidizer quantity whereas the efficiency of inert gases is in the same order. The coefficients of nitrogen equivalency however were found to differ to some extent. The explosion regions of 1,3-dioxolane/inert gas/oxidizer mixtures were modelled using the calculated adiabatic flame temperature profile (CAFTP) method as well as corrected adiabatic flame temperatures. The results indicate good agreement with experimental data for CO2, N2 and Ar- containing mixtures. The noticeable deviations that occur when He is the inert gas are due to the lacking transport data of that mixture. KW - Explosion limits KW - Flammability KW - CAFTP KW - Adiabatic Flame Temperatures PY - 2021 DO - https://doi.org/10.1016/j.jlp.2021.104496 SN - 0950-4230 VL - 71 SP - 4496 PB - Elsevier Ltd AN - OPUS4-52849 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Spitzer, Stefan A1 - Askar, Enis A1 - Hecht, Kristin A1 - Gabel, D. A1 - Zakel, S. A1 - Krietsch, Arne T1 - Requirements for a Hybrid Dust-Gas-Standard: Influence of the Mixing Procedure on Safety Characteristics of Hybrid Mixtures JF - Fire N2 - While developing a standard for the determination of safety characteristics for hybrid mixtures the authors discovered, that, beside the ignition source, the mixing procedure is the main difference between the single-phase standards for dusts and gases. The preparation of hybrid mixtures containing a flammable gas and a flammable dust in the 20 L-sphere can be realized in different ways. Either the flammable gas is filled only in the sphere or only in the dust container or in both. In previous works, almost always the first method is applied, without giving any information on the accuracy of the gas mixtures. In this work the accuracy of the gas mixtures and the results of the tests applying two methods of mixing were studied. No significant influence of the mixing method itself on the safety characteristics explosion pressure pex and the normalized rate of pressure rise (K-value) was found. Obviously, homogenization of the gas mixtures can be obtained sufficiently by the turbulence that is caused during the injection from the dust container into the explosion chamber within a short time. However, the mixing procedure has a great influence on the accuracy of the gas amount of the mixtures obtained. Without modifying the 20 L-sphere by installing precise pressure sensors, assuring its tightness and performing gas analysis, it must be expected, that the accuracy of the gas mixtures is very low. This has a significant influence on the measured safety characteristics and may lead to unsafe facilities or unnecessary expensive safety measures. KW - Hybrid mixtures KW - 20 L-sphere KW - Pre-ignition pressure rise KW - Post-injection pressure drop KW - Safety characteristics PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-554610 DO - https://doi.org/10.3390/fire5040113 VL - 5 IS - 4 SP - 1 EP - 10 PB - MDPI CY - Basel AN - OPUS4-55461 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -