TY - JOUR A1 - Jankuj, V. A1 - Mynarz, M. A1 - Krietsch, Arne A1 - Spitzer, Stefan A1 - Leipik, P. T1 - Experimental investigation of the consequences of acetylene pressure cylinder failure under fire conditions N2 - Acetylene pressure cylinders are widely used in the industrial sector for welding, flame cutting, or heating. Sometimes during work, not only with acetylene cylinders, fires occur and in this case the risk of destruction increases and the behavior of such an exposed cylinder is unpredictable. The purpose of this study is to identify those critical conditions when acetylene cylinders burst and explode in fires. In the present study, acetylene cylinders were exposed to fire conditions. For this purpose, a woodpile as a source of fire was chosen, tested, and evaluated. In addition to the fire condition, this option guaranteed reproducibility and similar conditions for all tests. The individual cylinders were equipped with thermocouples measuring the shell temperature, and half of them were prepared in order to measure the temperatures inside the cylinder. An important factor was the measurement of the amount of pressure that was achieved during the destruction of the cylinder. For this purpose, a pressure transducer was attached to the outlet of the cylinder valve. Exposed to direct fire, they can explode in 10 min, which was confirmed. The critical pressure of 40 bar has been reached in 6 min, followed by destruction after 7 min in fire. Cylinders with internal thermocouples were destroyed when lower pressure was achieved. This confirms the fact that any change of the pressure cylinder affects the original properties. After the tests, the fragments of the selected cylinders were subjected to material tests. The results obtained in these tests are the main source of information for understanding the behavior of acetylene cylinders in fire and the possibility of increasing the safety of intervening rescue services in an emergency. KW - Acetylene KW - Pressure Cylinders KW - Fire KW - Explosion KW - Fireball PY - 2022 DO - https://doi.org/10.1016/j.jlp.2022.104874 VL - 80 SP - 1 EP - 12 PB - Elsevier Ltd. CY - Amsterdam AN - OPUS4-55755 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Spitzer, Stefan A1 - Abed, Arkan A1 - Seifert, Alexander A1 - Salzano, Ernesto T1 - Risks from Hydrogen Carriers - Safety Characteristics of the LOHC System Toluene/Methylcyclohexane N2 - Reversible liquid organic hydrogen carriers (LOHCs) seem to be a promising solution for the transportation of hydrogen. Since no pressure or cooling needs to be applied during the transport, it is considered easier, safer and cheaper compared to pressurized gas tanks or cryogenic hydrogen on long routes and is already applied in large quantities and long distances. One simple system is methylcyclohexane and toluene. Toluene gets shipped to countries with an excess of (preferably green) energy and is charged with hydrogen to form methylcyclohexane. This is then shipped back to the place with energy and/or hydrogen demand and split into hydrogen and toluene. For toluene, some safety characteristics are available, whereas methylcyclohexane is loosely analyzed, hence safety characteristics are the basis for an appropriate approach to tackle the hazards and for the risk assessment. This paper focuses on the safety characteristics of both substances, compares the differences and points out the crucial hazards of this system, especially if the same tanks for transportation are used. T2 - 18th EFCE International Symposium on Loss Prevention and Safety Promotion in the Process Industries CY - Bologna, Italy DA - 08.06.2025 KW - Explosion protection KW - Rate of pressure rise KW - Hydrogen transport PY - 2025 DO - https://doi.org/10.3303/CET25116058 SN - 2283-9216 VL - 116 SP - 343 EP - 348 PB - AIDIC Servizi S.r.l. CY - Italy AN - OPUS4-63734 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kosár, László A1 - Szabová, Zuzana A1 - Kuracina, Richard A1 - Spitzer, Stefan A1 - Mynarz, Miroslav A1 - Filipi, Bohdan T1 - Study of the Safety Characteristics of Different Types of Pepper Powder (Capsicum L.) N2 - This research was aimed at comparing the fire characteristics of different types of pepper in the context of explosion prevention. The following characteristics were studied: explosion pressure Pmax and Kst at selected concentrations, ignition temperature of the deposited dust layer from the hot surface, and minimum ignition energy. The comparison of the chemical properties of the used types of pepper was performed using TG/DSC. The results of the measurements suggest that different types of peppers exhibit different explosion characteristics. Each sample reached the maximum value of the explosion pressure and rate of pressure rise at different concentrations. The volume of the explosion chamber used also influenced the explosion characteristics. It is a consequence of the fact that the explosion characteristics strongly depend on the mechanism of action of a particular igniter. The minimum effect on the safety characteristics was observed when measuring the minimum ignition energy and the minimum ignition temperature of the dust layer from the hot surface. The results of the measurements suggest that different types of peppers exhibit different explosion characteristics. This information should then be considered in explosion prevention. KW - Dust explosions KW - Pepper samples KW - Explosion characteristics KW - Explosion protection PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-605965 DO - https://doi.org/10.3390/fire7070229 VL - 7 IS - 7 SP - 1 EP - 14 PB - MDPI AG AN - OPUS4-60596 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Recknagel, Christoph A1 - Spitzer, Stefan A1 - Hoppe, Johannes A1 - Wenzel, Norman A1 - Pirskawetz, Stephan T1 - Innovative Sensorik für Fugensysteme N2 - Die zielgerichtete Weiterentwicklung von Bauteilen und Konstruktionselementen im Straßenbau hochbeanspruchter Verkehrswege unserer Infrastruktur (Bundesfernstraßen) erfordert spezielle, bauteiladaptierte technische Möglichkeiten/Sensorik zur Quantifizierung des Gebrauchsverhaltens. Bei Fugen in Verkehrsflächen stellen insbesondere langsam und schnell ablaufende Plattendeformationen infolge jahreszeitlicher und verkehrlicher Beanspruchungen maßgebende Beanspruchungszustände dar. Eine Quantifizierung dieser Einwirkungen hilft bei der Weiterentwicklung sowie auch bei der Bewertung optimierter technischer Lösungen. In Forschung kompakt 17/21 „Innovative Sensorik für Fugensysteme“ wird eine neuartige, robuste Lösung der BAM zur Datenerfassung und Bauwerksmonitoring von hochbeanspruchten Verkehrsflächen aus Beton vorgestellt. KW - Betonfahrbahndecke KW - Fugen KW - Quantifizierung realer Verformungen PY - 2021 VL - 17 SP - 1 EP - 2 PB - Eigenverlag der BASt CY - BASt, Bergisch Gladbach AN - OPUS4-54115 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - Recknagel, Christoph A1 - Spitzer, Stefan A1 - Hoppe, Johannes A1 - Wenzel, Norman A1 - Pirskawetz, Stephan T1 - Optimierung von Fugensystemen - Messtechnische Grundlagen zur Ermittlung realer Beanspruchungen in situ N2 - Voraussetzung zur Aufklärung von Fugenbewegungen in hochbeanspruchten Verkehrsflächen aus Beton ist ein neues, innovatives und sensitives Sensorsystem, welches unter den Bedingungen der Autobahnpraxis schnell und sicher in entsprechend beanspruchte Bereiche installiert werden kann und in der Lage ist, stabile und hochaufgelöste Bewegungen in mehrere Raumrichtungen zu erfassen. Das durch die BAM neu entwickelte Sensorsystem ist geeignet, um direkt in die Betonfahrbahndecke integriert zu werden und sowohl über saisonale Messbereiche als auch in hoher Auflösung entsprechende Messwerte online zu erfassen und bereit zu stellen. Das für diesen Zweck entwickelte innovative Sensorsystem kann direkt in die Rollspur auf beiden Seiten der Fuge eingebaut werden und ist dafür ausgelegt, Lkw-Überfahrungen zu widerstehen. Es ist schnell und präzise genug, um die realen Bewegungen in allen drei Raumachsen in Echtzeit erfassen zu können. Dieser Forschungsbericht beschreibt das Funktions- und Wirkschema des Sensorsystems und seine Validierung im Labor- und Feldmaßstab. Dabei wird insbesondere auch die praxisgerechte Einbau- und Nutzungsmethodik vorgestellt. Auflösungsvermögen, Robustheit und Nutzerfreundlichkeit werden am Beispiel einer Konzeptstudie auf dem Testgelände DuraBASt erprobt. Es werden grundlegende Hinweise auf den dringlichen Bedarf einer gebrauchsgerechten Beschreibung des realen Verhaltens des Bauwerks Betonstraße identifiziert. Die mit dem Sensorsystem gewonnenen Daten können eine Grundlage für die Konzeption einer performance-basierten Bewertung von Fugenfüllsystemen in Betondecken von Bundesautobahnen bieten. Sie sind geeignet, die Funktionsmechanismen der verschiedenen Betonfahrbahnkonstruktionen besser zu verstehen und zielgerichtet konstruktive und materialtechnische Optimierungen und Fortentwicklungen von Fugenkonstruktionen und Fugenfüllsystemen in gebrauchsbezogener Weise zu entwickeln. Durch weitere Datenerhebung, -fusion und -analyse können Instandsetzungsintervalle und Lebensdauerzyklen besser abgeschätzt und geplant werden. KW - Betonfahrbahndecke KW - Fugen KW - Quantifizierung realer Verformungen PY - 2021 SN - 978-3-95606-590-3 SN - 0943-9323 VL - Straßenbau Heft S 153 SP - 1 EP - 173 PB - Fachverlag NW in der Carl Ed. Schünemann KG CY - Bremen AN - OPUS4-54174 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Spitzer, Stefan A1 - Reitmeier, Fabian A1 - Danzi, Enrico A1 - Janovsky, Bretislav A1 - Paul, Michael T1 - The Exploding Wire: A novel ignition source for the determination of safety characteristics of dusts and hybrid mixtures N2 - For the determination of safety characteristics of dusts there are mainly chemical igniters in use. Especially for the maximum explosion pressure and the maximum rate of pressure rise there is no standard with another ignition source. The chemical igniters have the disadvantage of being very hard to obtain in most countries and they are even illegal in some. This leads to the fact, that those countries are not able to investigate the safety characteristics or only with a high effort by sending dust samples to facilities outside the country. This article presents a novel ignition source and describes how to build it. It is also the first step to place this ignition source into the dust standards in the future. KW - Explosion protection KW - Dust explosions KW - Pressure rise PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-645209 DO - https://doi.org/10.1016/j.elstat.2025.104188 SN - 0304-3886 VL - 138 SP - 1 EP - 8 PB - Elsevier B.V. AN - OPUS4-64520 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Spitzer, Stefan A1 - Jankuj, V. A1 - Hecht, K. A1 - Krietsch, Arne T1 - Igniting volume of four ignition sources N2 - Several standardized ignition sources are used to determine the safety characteristics of gases, vapours and dusts. Standards indicate the source of ignition but vary in specifying other features such as the burning duration, energy or the volume in which the energy is released. Since heat is not visible under normal conditions, a schlieren technique was used to visualize the entire igniting volume and not just the flames. This article focuses on the igniting volume, compares it among the four standardized ignition sources and displays its relationship to the size of the test vessel. Differences in the ignition behaviour of the ignition sources might lead to the determination of erroneous safety characteristics and with that to the unsafe operation of processes. KW - Hybrid mixtures KW - 20L-sphere KW - Ignition sources KW - Exploding wire PY - 2023 DO - https://doi.org/10.1016/j.psep.2022.12.076 SN - 0957-5820 VL - 170 SP - 1200 EP - 1207 PB - Elsevier CY - Amsterdam AN - OPUS4-56855 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 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 - 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 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 - CONF A1 - Spitzer, Stefan A1 - Askar, Enis A1 - Krietsch, Arne A1 - Schröder, Volkmar T1 - Comparative study on standardized ignition sources used for explosion testing N2 - For the determination of safety characteristics of gases, vapors and dusts different types of ignition sources are used in international standards and guidelines. Table 1 compares technical relevant ignition sources with their main features. 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 by Scheid et al. Using the exploding wire, the ignition energy can be varied from 2 to 10 000 J (2 x 5 000 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 - Online meeting DA - 27.07.2020 KW - Ignition source KW - Exploding Wire KW - Hybrid mixtures KW - Safety characteristics determination PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-517908 UR - https://oar.ptb.de/files/download/5f3e662f4c93901010006dbf DO - https://doi.org/10.7795/810.20200724 VL - 13 SP - 864 EP - 875 PB - PTB Physikalisch-Technische Bundesanstalt Braunschweig AN - OPUS4-51790 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -