TY - THES A1 - Klippel, Alexander T1 - Investigations into the influence of dustiness on the course of vented dust explosions N2 - A new safety characteristic named “dustiness” according to the German guideline VDI 2263 – part 9 is investigated. Dustiness describes the tendency of a powder to form airborne dust by a prescribed mechanical stimulus. Dusts often behave differently in a dust/air mixture or in the case of a dust explosion, even if they have comparable physical properties such as particle size and density. In order to look into the effects of dustiness on dust cloud Formation and explosion properties experiments and simulations in a 75 L vertical dust Dispersion glass tube apparatus were carried out. In a second step industrial-scale experiments were carried out in a 50 m³ silo. Experiments showed that particle size and density are not the only factors which influence dustiness, since the chosen dusts with comparable densities and particle size distributions showed very different behavior in the flow. Other dust properties such as particle shape, specific surface area, humidity and agglomeration processes have an influence which can outweigh size and density. Preliminary explosion experiments showed that dustiness has an influence on the reduced explosion pressure and pressure rise in a vented 75 L test apparatus. In order to verify the results for applications in the process industries further tests with different settings were carried out in industrial-scale experiments. First dust concentration measurements were done in order to evaluate the reproducibility of filling processes. Experiments showed that single tests differed by 30 % and more from the average depending on dust sample and filling method. First explosion experiments with a worst-case scenario in terms of high turbulence and homogenous dust distribution showed that the maximum reduced explosion pressures were well below the calculated values. Reduced explosion pressures and rates of pressure rise of the hree tested dust were as their Explosion characteristics pmax and KSt let suggest. The Euler/Lagrange and the Euler/Euler approaches were compared simulating dust/air mixtures. Especially sedimentation and the ability of the approaches to simulate the tendency of dust to stay airborne were investigated. The Euler/Lagrange approach is better suited for simulating local dust concentrations, particle size distributions and particle forces. With the Euler/Euler method it is possible to achieve fast solutions for one specified diameter. The computational fluid dynamics code ANSYS CFX R14 was used for all simulations. N2 - Eine neue sicherheitstechnische Kennzahl, das Staubungsverhalten gemäß VDI Richtlinie VDI 2263 – Blatt 9, wird hinsichtlich ihres Nutzens für den Staubexplosionsschutz untersucht. Unter Staubungsverhalten versteht man die Tendenz eines Staubes, Wolken aufgrund eines festgelegten mechanischen Stimulus zu bilden. Stäube können sich bei vergleichbareren physikalischen Eigenschaften wie Dichte oder Partikelgrößenverteilung, teilweise sehr unterschiedlich in einem Staub/Luft-Gemisch oder im Falle einer Staubexplosion verhalten. Um den Einfluss des Staubungsverhaltens auf die Staubwolkenbildung und den Ablauf von Explosionen zu untersuchen, wurden Experimente und Simulationen in einer vertikalen 75 L Rohrapparatur durchgeführt. Mit den Erkenntnissen aus diesen Laborversuchen wurden weitere Versuche im Realmaßstab in einem 50 m³ Silo durchgeführt. Versuche im Labormaßstab in einem druckentlasteten 75 L Behälter haben gezeigt, dass das Staubungsverhalten einen Einfluss auf die reduzierten Explosionsdrücke, die zeitlichen Druckanstiege und die Flammengeschwindigkeiten hat. Um die Versuchsergebnisse für den industriellen Maßstab zu belegen, wurden Versuche in einem 50 m³ Silo durchgeführt. Dabei wurde zunächst die Reproduzierbarkeit von Befüllungsvorgängen mit Staubkonzentrationsmessungen durch mehrere Wiederholungsversuche überprüft. Dabei ergaben sich Abweichungen von 30 % und mehr im Vergleich zum Mittelwert der Versuche. Erste Explosionsversuche eines Worst-Case-Szenarios mit hoher Turbulenz und möglichst homogenen Staubwolken ergaben deutlich niedrigere reduzierte Explosionsdrücke als die mit den empirischen Gleichungen berechneten. Der Explosionsverlauf war in Übereinstimmung mit den Kenngrößen pmax und KSt. Bei der Simulation von Staub/Luft-Gemischen wurden mit dem Euler/Lagrange- und dem Euler/Euler-Ansatz verwendet. Dabei wurde vor allem untersucht inwiefern das Sedimentations- und Staubungsverhalten modelliert werden können. Es zeigte sich, dass der Euler/Lagrange-Ansatz besser geeignet ist lokale Staubkonzentrationsverteilungen, Partikelgrößenverteilungen und -kräfte zu simulieren. Der Euler/Euler-Ansatz ermöglicht generelle Aussagen in kürzerer Rechenzeit für eine definierte Partikelgröße. Der numerische Strömungslöser ANSYS CFX V14 wurde für alle Simulationen benutzt. T3 - BAM Dissertationsreihe - 123 KW - dustiness KW - Euler/Lagrange approach KW - vented dust explosion KW - dust explosion protection KW - CFD PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-4635 SN - 978-3-9816668-2-3 VL - 123 SP - 1 EP - 207 PB - Bundesanstalt für Materialforschung und -prüfung (BAM) CY - Berlin AN - OPUS4-463 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Klippel, Alexander A1 - Scheid, Marc A1 - Krause, U. ED - Makhviladze, G. ED - Molkov, V. ED - Bradley, D. ED - Sunderland, P. ED - Tamanini, F. T1 - Progress on the research into the influence of dustiness on dust explosions N2 - In practice, occurring explosive dust/air mixtures are usually not homogeneous and in many cases do not spread over the whole enclosure. For the safety measure explosion venting, a smaller venting area might be sufficient as calculated according to venting standards (EN 14491 'Dust Explosion Venting Protective Systems'). The tendency of bulk materials to form dust clouds is not taken into account so far. To optimize the design of explosion protection measures, a new safety characteristic the so-called 'dustiness' (see VDI 2263 part 9 'Determination of Dustiness of Bulk Materials'.) could be useful. Dustiness means the tendency of dust to form dust clouds. There are six dustiness groups (DG) from one to six (one means little tendency to stay airborne, six the opposite). The paper describes first results on the reasons for different dustiness and on dust explosion venting for several dusts of different dustiness. A 75 L vertical tube apparatus for vented dust explosion experiments was created. Pressure, pressure rises and flame speeds were measured to evaluate the course of the dust explosions. In addition the paper includes CFD simulations (ANSYS CFX) about the possibilities to model the dust/air mixtures with the Euler/Lagrange approach. In order to simulate the settling of dust clouds more realistic the particle surface area was adjusted and the particle size distribution was taken into account. Results were compared to experimentally determined terminal velocities. T2 - ISFEH7 - 7th International seminar on fire & explosion hazards CY - Providence, RI, USA DA - 05.05.2013 KW - CFD KW - Dust explosions KW - Dustiness KW - Venting PY - 2013 SN - 978-981-07-5936-0 SN - 978-981-07-5940-7 DO - https://doi.org/10.3850/978-981-07-5936-0_13-01 SP - 781 EP - 790 PB - Research Publishing AN - OPUS4-28502 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Klippel, Alexander A1 - Scheid, Marc A1 - Krause, U. T1 - Progress on the Research into the Influence of Dustiness on Dust Explosions T2 - 7th International Seminar Fire and Explosions Hazards CY - Providence, RI, USA DA - 2013-05-05 PY - 2013 AN - OPUS4-28539 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Klippel, Alexander A1 - Scheid, Marc A1 - Krause, U. T1 - Investigations into the influence of dustiness on dust explosions N2 - A new safety characteristic the 'dustiness' according to VDI 2263 – part 9 (Verein Deutscher Ingenieure, 2008) is investigated. Dustiness means the tendency of a dust to form clouds. The paper deals with the influence of the dustiness on vented dust explosions. In order to look into the effects of the dustiness on dust cloud formation and explosion properties experiments and simulations in a vertical dust dispersion glass tube apparatus were carried out. Preliminary explosion experiments showed that the dustiness has an influence on the reduced explosion pressure in a vented 75 L test apparatus. Dusts with comparable pmax and KSt values and different dustiness were tested. Dusts with higher dustiness produced higher overpressures, despite comparable safety characteristics. In order to verify the results for applications in the process industries further tests with different settings are planned as well as industrial scale experiments. Characteristics of the dust such as particle size, density, specific surface area and particle shape, which influence the dispersibility, have been determined experimentally. The Euler/Lagrange and the Euler/Euler approaches are compared for simulating an exemplary dust/air mixture. Especially sedimentation and the ability of the approaches to simulate the tendency of dust to stay airborne were investigated. The Euler/Lagrange approach is better suited for simulating local dust concentrations, particle size distributions and particle forces. It could be used to point out regions of high dust concentrations in a vessel. With the Euler/Euler method it is possible to achieve fast solutions for one specified diameter, but the simulated dust/air mixtures are always more homogenous than in reality. ANSYS CFX version 13 was used in all simulations. KW - Dust explosion KW - Dustiness KW - Dispersion KW - Venting KW - Computational fluid dynamiics (cfd) KW - Two-phase flow PY - 2013 DO - https://doi.org/10.1016/j.jlp.2013.07.016 SN - 0950-4230 SN - 1873-3352 VL - 26 SP - 1616 EP - 1626 PB - Elsevier Ltd. CY - Guildford, Surrey AN - OPUS4-29000 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Klippel, Alexander A1 - Scheid, Marc A1 - Koperski, January A1 - Wappler, Mike A1 - Krause, Ulrich T1 - Influence of dustiness on small-scale vented dust explosions N2 - A new safety characteristic the 'dustiness' according to VDI 2263 – part 9 (Verein Deutscher Ingenieure, 2008) is investigated. Dustiness means the tendency of a dust to form clouds. The paper deals with the physical reasons for the different behavior of dusts, even if they have similar properties such as particle size and density and the influence of the dustiness on dust explosions. In order to study the effects of the dustiness on dust cloud formation for different dispersion methods experiments in a vertical dust dispersion glass tube apparatus were carried out. Furthermore vented dust explosion experiments were done for two different dispersion methods and two static activation pressures. Experiments show that particle size and density are not the only factors which influence dispersibility. Particle shape, specific surface area, flow and dispersion method have an influence which can outweigh size and density. Preliminary explosion experiments showed that the dustiness has an influence on the reduced explosion pressure and flame speed in a vented 75 L test apparatus. In order to verify the results for applications in the process industries further tests with industrial scale experiments are planned. KW - Dust explosion KW - Dustiness KW - Dispersion KW - Venting PY - 2013 DO - https://doi.org/10.1016/j.jlp.2013.09.006 SN - 0950-4230 SN - 1873-3352 VL - 26 SP - 1433 EP - 1441 PB - Butterworth CY - Guildford, Surrey AN - OPUS4-29283 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Klippel, Alexander A1 - Schmidt, Martin A1 - Scheid, Marc A1 - Krause, U. T1 - Staubexplosionsschutz - Einfluss des Staubungsverhaltens auf druckentlastete Staubexplosionen T2 - 11. Fachtagung Anlagen-, Arbeits- und Umweltsicherheit CY - Köthen, Germany DA - 2013-11-07 PY - 2013 SN - 978-3-86011-058-4 IS - P-18 SP - 1 AN - OPUS4-29546 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Klippel, Alexander A1 - Schmidt, Martin A1 - Scheid, Marc A1 - Krause, U. T1 - Einfluss des Staubungsverhaltens auf druckentlastete Staubexplosionen T2 - 11. Fachtagung "Anlagen-, Arbeits- und Umweltsicherheit" CY - Köthen, Germany DA - 2013-11-07 PY - 2013 AN - OPUS4-29500 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Klippel, Alexander A1 - Scheid, Marc A1 - Krause, Ulrich T1 - Investgations into the Influence of Dustiness on Dust Explosions T2 - IX ISHPMIE CY - Kraków, Poland DA - 2012-07-23 PY - 2012 AN - OPUS4-26552 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zur, Malte A1 - Klippel, Alexander A1 - Otremba, Frank A1 - Leder, A. T1 - Numerical simulation and experimental study of cabin-airflow and transport of gas-mixtures in aircraft cargo compartments: model validation N2 - Dangerous goods are transported as air freight in commercial aircrafts. Using plastic jerrycans or plastic containers, liquids or gases can escape by leakage or permeation effects. Prior research by the German Federal Institute for Materials Research and Testing (BAM) showed that the lower explosion limit can be reached when transporting dangerous goods in sea-freight containers under normal transportation situations. This motivated the presented study of the transportation situation of dangerous goods in cargo compartments of commercial airplanes. The scope of this paper is to present the experimental method used for validating a numerical model for CFD (Computational Fluid Dynamics) simulations. The CFD model will be used in a future study to evaluate the potential risk from transporting dangerous goods. The objective of this paper is to present the model mock-up of an aircraft cargo compartment and some examples of three dimensional velocity profiles of the air flow in the mock-up. The velocity profiles are calculated using numerical simulations and measured by Laser-Doppler-Anemometry (LDA) experiments. The mock-up is a generic model of a wide-body aircraft lower deck cargo compartment in a 1:10 scale. Geometry, air exchange rates and inlet as well as outlet flow conditions in the cargo compartment are modeled using realistic boundary conditions. The commercial CFD (Computational Fluid Dynamics) code ANSYS CFX 14 is used for numerical flow simulations applying RANS (Reynolds-Averaged-Navier-Stokes) equations and turbulence models. The turbulence models studied are the renormalization group k-ε-model (RNG), the Reynolds-Stress model by Launder, Reece and Rodi (LRR) and the SST-k-ω-model by Menter (SST). The flow measurement with LDA in the mock-up of a cargo compartment proves to be a feasible method for producing data to validate CFD simulations. Qualitative evaluation of the results shows a good overall agreement between numerical and experimental results. The experimental validation indicates that the implemented CFD model is capable of reproducing the flow situation in the model mock-up. T2 - ASME 2013 Fluids engineering summer meeting - 7th International symposium on flow applications in aerospace CY - Incline Village, Nevada, USA DA - 07.07.2013 KW - Computational fluid dynamics KW - Aircraft cabin air flow KW - Gas mixtures KW - Model validation PY - 2013 SN - 978-0-7918-5555-3 IS - Paper FEDSM2013-16622 SP - 1 EP - 9 AN - OPUS4-30076 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Klippel, Alexander A1 - Schmidt, Martin T1 - Einfluss des Staubungsverhaltens auf druckentlastete Staubexplosionen und neues vom explodierenden Draht als alternative Zündquelle T2 - 58. Sitzung des Arbeitsausschusses "Sicherheitstechnische Kenngrößen"; ProcessNet CY - Frankfurt am Main, Germany DA - 2014-04-03 PY - 2014 AN - OPUS4-30561 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Klippel, Alexander A1 - Schmidt, Martin A1 - Mücke, Olaf A1 - Krause, U. T1 - Dust concentration measurements during filling of a silo and CFD modeling of filling processes regarding exceeding the lower explosion limit N2 - Measurement and numerical simulation of local dust concentrations over time in a vessel can only be done with some uncertainty due to the complexity of the behavior of dust/air mixtures. Dust concentration was measured in a 50 m³ vessel and compared to simulations with a commercial CFD code. A 50 m³ silo was used with two different filling methods. In one setup dust was conveyed with pneumatic filling at the top. The other filling was done with pressurized air and a homogenous injection via eight nozzles. Experiments were repeated three to four times with two kinds of dusts and the results were used to evaluate reproducibility of dust concentration measurements over time in a vessel depending on the filling method. Dust concentrations over time varied up to 30% from the average for homogenous injection and even more for pneumatic filling. Numerical investigations were done with maize starch. Measured concentrations were compared to simulated ones with the commercial CFD code ANSYS CFX R14 using an Euler/Lagrange approach. Drag force, turbulent dispersion force, particle size distribution, particle surface area and particle/particle interaction were modeled. A general agreement of measurement and simulation was achieved. Numerical simulations of filling processes were used to predict parts of the vessel where the lower explosion limit is reached and exceeded. This could help to improve dust explosion protection, if it is used to find configurations where the dust concentration exceeds the lower explosion limit only in small parts of the vessel during filling, e.g. using different injection points or injection angles. The volume where LEL is reached or exceeded in a 50 m³ silo is shown for pneumatic and homogenous filling. Volume of combustible atmosphere in the vessel over time is compared for two pneumatic filling configurations and one worst-case homogenous injection configuration. KW - CFD KW - Euler/Lagrange approach KW - Dust explosion protection KW - Dust concentration measurement KW - Dust explosion KW - Dustiness KW - Dispersion KW - Venting PY - 2014 DO - https://doi.org/10.1016/j.jlp.2014.02.006 SN - 0950-4230 SN - 1873-3352 VL - 29 SP - 122 EP - 137 PB - Butterworth CY - Guildford, Surrey AN - OPUS4-30330 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Klippel, Alexander A1 - Schmidt, Martin A1 - Krause, Ulrich T1 - Einfluss des Staubungsverhaltens auf druckentlastete Staubexplosionen T2 - 3. Doktorandentag am Lehrstuhl Anlagentechnik und Anlagensicherheit der Otto-von-Guericke Universität Magdeburg CY - Magdeburg, Germany DA - 06.12.2013 PY - 2013 AN - OPUS4-30260 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Klippel, Alexander A1 - Schmidt, Martin A1 - Krause, U. T1 - Dustiness in workplace safety and explosion protection - review and outlook N2 - Behavior of dust/air mixtures is very complex and difficult to predict since it depends on material properties as well as boundary conditions. Without other influences airborne particles deposit due to gravity but the time it takes for total deposition as well as easiness of resurrection depends very much on the specific dust sample and the boundary conditions. It still lacks a complete understanding of all interacting reasons and one approach is using experimentally determined characteristics, one is named dustiness. Dustiness is the tendency of dust to form clouds and to stay airborne. Dustiness is determined with two basic principles, which are light attenuation and ratio of filled-in and measured mass. Assessment of dustiness of industrial powders has been done for a long time regarding work place safety. Dustiness is used there to determine inhalable fraction and to evaluate health risks. Lately it became interesting in dust explosion protection as well. Dustiness could be used to optimize determination of zones, adaption of venting area and/or for positioning of suppression systems. Dustiness can be useful in many ways but is not a physical property of dusts, therefore it depends on material properties such as density, particle size distribution, shape and water content as well as boundary conditions or determination method. This makes it very difficult to compare dustiness for different techniques and apparatuses and determination method as well as results should be considered carefully. This work gives an overview of existing standards, recent research and suggests improvements to the new dustiness as proposed for dust explosion protection. KW - Dustiness KW - Measurement methods KW - Workplace exposure KW - Dust explosion protection PY - 2015 DO - https://doi.org/10.1016/j.jlp.2015.01.011 SN - 0950-4230 SN - 1873-3352 VL - 34 SP - 22 EP - 29 PB - Butterworth CY - Guildford, Surrey AN - OPUS4-32467 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schmidt, Martin A1 - Klippel, Alexander T1 - Der Einfluss des Staubungsverhaltens auf druckentlastete Staubexplosionen - experimentelle und numerische Untersuchungen N2 - Die Auslegung von Einrichtungen zur Druckentlastung von Staubexplosionen erfolgt in der Regel gemäß DIN EN 14491. Die Norm enthält empirische Gleichungen mit denen, unter Verwendung der sicherheitstechnischen Kenngrößen maximaler Explosions(über)druck und maximaler zeitlicher Druckanstieg bzw. dem KSt-Wert, erforderliche Entlastungsflächen zum konstruktiven Schutz von Behältern und Anlagen berechnet werden. Das Verfahren ermög-licht in der Regel eine konservative Auslegung von Entlastungsflächen. Zur praxisgerechte-ren Betrachtung erfolgten der Vergangenheit bereits Untersuchungen zum Einfluss bestimm-ter Verfahren zur Produkteinleitung bzw. Befüllung auf die Bildung von Staubwolken in Silos oder Behältern, welche einen wesentlichen Einfluss auf die erforderliche Druckentlastungs-fläche aufweisen. Bisher unberücksichtigt blieb, dass die Bildung von Staubwolken sehr stark von den chemischen und physikalischen Eigenschaften des Schüttgutes abhängt. Da auch bei scheinbar ähnlichen Produkten das Aufwirbel- und Schwebeverhalten sehr unterschied-lich sein kann, ist hierdurch ein erheblicher Einfluss auf die Bildung explosionsfähiger Staub/Luft-Gemische und damit auf die erforderliche Entlastungsfläche zu erwarten. Ziel experimenteller und numerischer Untersuchungen war es daher, den Einfluss des Ver-mögens von Stäuben aufgewirbelt zu werden bzw. deren Dispergierverhalten in Luft auf die erforderliche Druckentlastungsfläche zu ermitteln. Hierbei sollte überprüft werden, inwieweit bei Stäuben mit geringer Staubungsneigung eine Verringerung der Druckentlastungsfläche möglich ist. Die durchgeführten Untersuchungen zeigten, dass die Randbedingungen, insbesondere die Strömungsrandbedingungen, die bei einem Verarbeitungs- oder Förderprozess vorliegen, einen wesentlich stärkeren Einfluss auf die Dispergierung eines Staubes aufweisen als sein Staubungsverhalten. Eine Anpassung bzw. Reduzierung der Druckentlastungsfläche allein auf Basis des Staubungsverhaltens ist daher nicht möglich. T2 - 12. Fachtagung Anlagen-, Arbeits- und Umweltsicherheit CY - Köthen, Germany DA - 05.11.2015 KW - Staubexplosionen KW - Staubungsverhalten KW - Explosionsschutz PY - 2015 SN - 978-3-86011-091-1 SP - C-03, 1-15 AN - OPUS4-34944 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krietsch, Arne A1 - Kwangvitayanon, Yolada A1 - Schmidt, Martin A1 - Klippel, Alexander A1 - Schröder, Volkmar A1 - Scheid, M. T1 - Validation of the new ignition source 'exploding wire' for dust explosion testing in the 20-L-sphere N2 - The safety characteristics Maximum Explosion Pressure pniB, Maximum Explosion Pressure Rise (dp/dt)™* and Lower Explosion Limit LEL are determined in closed vessels such as the 20-L-sphere according to international Standards. Dust ignition is carried out using pyrotechnical igniters which are defined in the Standards. Due to various disadvantages of pyrotechnical igniters the need for alternative ignition sources arises again and again. Studies at the Federal Institute for Material Research and Testing (BAM) with ignition units which were able to generate ignition energies up to 2000 J showed that the so-called “exploding wire” or “fuse wire“ is suitable as an alternative ignition source. The paper presents further test results for the Validation of the exploding wire for the determination of Pm» and (dp/dt)mx in the 20-L-sphere. The tests were performed with a new ignition unit and improved electrodes which allowed ignition energies up to 10000 J. The paper also analyses propagation of flame and electrical arc on basis of high speed camera recordings. Turbulence measurements with a LDA System in the 20-L-sphere allowed investigation whether the activation of the ignition sources has an influence on the turbulence field generated during dust dispersion and whether the influence differs depending on the ignition source. T2 - Hazards 24 Symposium CY - Edinburgh, UK DA - 07.05.2014 KW - Dust explosion testing KW - Exploding wire KW - Explosion characteristics KW - Ignition source PY - 2014 SN - 978-0-85295-582-6 N1 - Serientitel: IChemE Symposium Series – Series title: IChemE Symposium Series VL - 159 SP - 1 EP - 7 AN - OPUS4-31145 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Scheid, Marc A1 - Klippel, Alexander A1 - Tschirschwitz, Rico A1 - Schröder, Volkmar A1 - Zirker, Stefan A1 - Kusche, Christian ED - Makhviladze, G. ED - Molkov, V. ED - Bradley, D. ED - Sunderland, P. ED - Tamanini, F. T1 - New ignition source 'exploding wire' for the determination of explosion characteristics of combustible dusts in the 20-L sphere N2 - According to international standards several safety characteristics of dusts are determined in the 20-L sphere (also known as SIWEK-Chamber). Dust cloud ignition is carried out using pyrotechnical igniters. Due to various disadvantages of pyrotechnical igniters the need for alternative ignition sources arises again and again. An alternative ignition source could be the so-called 'exploding wire' or 'fuse wire'. The paper presents test results of a comparative study between both ignition sources for the determination of the safety characteristics Maximum Explosion Pressure and Maximum Rate of Explosion Pressure Rise of selected dusts in the 20-L sphere. In addition the propagation of flame and electrical arc was analysed by high speed camera recordings. Tests in a windowed autoclave were performed to get information on the influence of turbulence during ignition on the shape of the generated flame (electrical arc) and its propagation. Turbulence measurements with a LDA system in the windowed autoclave as well as in the 20-L sphere allowed investigation if the ignition sources led to an additional turbulence increase at the moment of ignition in comparison to tests without ignition. T2 - ISFEH7 - 7th International seminar on fire & explosion hazards CY - Providence, RI, USA DA - 05.05.2013 KW - Dust explosion testing KW - Exploding wire KW - Explosion characteristics KW - Ignition source KW - Sicherheitstechnische Kenngrößen Staub KW - Staubexplosionsschutz KW - Explodierender Draht KW - Alternative Zündquelle PY - 2013 SN - 978-981-07-5936-0 SN - 978-981-07-5940-7 DO - https://doi.org/10.3850/978-981-07-5936-0_13-04 SP - 810 EP - 819 PB - Research publishing AN - OPUS4-28553 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Scheid, Marc A1 - Klippel, Alexander A1 - Tschirschwitz, Rico A1 - Schröder, Volkmar A1 - Zirker, Stefan A1 - Kusche, Christian T1 - New ignition source 'exploding wire' for the determination of explosion characteristics of combustible dusts in the 20-L-sphere N2 - According to international Standards several safety characteristics of dusts are determined in the 20-L-sphere (also known as SIWEK-Chamber). Dust cloud ignition is carried out using pyrotechnical igniters. Due to various disadvantages of pyrotechnical igniters the need for alternative ignition sources arises again and again. An alternative ignition source could be the socalled “exploding wire” or “fuse wire". The paper presents test results of a comparative study between both ignition sources for the determination of the safety characteristics Maximum Explosion Pressure and Maximum Rate of Explosion Pressure Rise of selected dusts in the 20-Lsphere. In addition to that the flame/arc propagation of both ignition sources was analysed by high speed and IR camera recordings. Tests in a windowed autoclave were performed to get information on the influence of turbulence generated due to dispersion of the dust on the shape of the generated flame and its propagation. Turbulence measurements in the windowed autoclave as well as in the 20-L-sphere with a LDA System allowed investigation if the igniter led to turbulence increase at the moment of ignition in comparison to tests without ignition. T2 - GCPS 2013 - 9th Global congress on process safety CY - San Antonio, TX, USA DA - 28.04.2013 KW - Sicherheitstechnische Kenngrößen Staub KW - Staubexplosionsschutz KW - Explodierender Draht KW - Alternative Zündquelle PY - 2013 SN - 978-0-8169-1075-5 SP - 1 EP - 10 AN - OPUS4-28552 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hofmann-Böllinghaus, Anja A1 - Dülsen, Steffen A1 - Klippel, Alexander T1 - Problems in bus fire safety - recent developments and possible solutions N2 - Not only the severe bus fire in 2008 near Hanover in Germany with 20 fatalities showed the fire danger for coaches1,2. Also two other similar fires in Germany in May 2011 and February 2012 showed the extremely hazardous situations a fire can cause in bus3,4. In both cases young and fit passengers (pupils) could only escape because they were able to destroy Windows and escaped by jumping out of these Windows. In one case they had to escape out of the Windows of the upper deck and several were severe injured. These numerical and experimental investigations of bus fires in coaches and city buses performed by BAM are funded by the German Ministry of Transport, Building and Urban Development. Web and literature research showed that fires occur much more often than assumed. Most of the fires Start in the engine compartment. However, often the whole bus is destroyed after a fire. One reason for the rapid fire development are the fire safety regulations for the bus materials which are on a much lower level than in the other transport sectors1,2,5,6’. A lot of materials from suppliers and of operating city buses were investigated experimentally. The results were compared with regulations in the train sector because trams and city buses, trains and coaches are working under similar operating conditions, e.g. for escape possibilities. These results were used to investigate bus fires also numerically to identify very hazardous scenarios by varying materials properties, geometries and air condition settings. Additionally real scale experiments were performed on different bus seats; ignited by a paper cushion. Especially the newer bus seats showed a very low fire performance with high heat and smoke release rates. Surprisingly a city bus seat of an older bus (built in 1995) showed a better fire performance. It is assumed that the trend to cheaper and lightweight plastics is one reason that modern seats have worse fire performance. Large scale tests were performed on a city bus - smoke development, fire detection and suppression in the engine area. Several possible enhancements are discussed and recommendations are given to make buses more fire safe. T2 - Fire and materials 2013 - 13th International conference and exhibition CY - San Francisco, CA, USA DA - 28.01.2013 KW - Large scale fire tests KW - Bus materials investigation KW - Numerical fire simulation KW - CFD KW - Recommendations PY - 2013 SP - 563 EP - 574 PB - Interscience Communications CY - London, UK AN - OPUS4-28600 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Hofmann-Böllinghaus, Anja A1 - Krüger, Simone A1 - Klippel, Alexander T1 - Experimental and numerical investigations of the burning behavior of vehicle materials small, intermediate and large scale investigations T2 - Interflam 2010 - 12th International fire science & engineering conference (Proceedings) CY - Nottingham, UK DA - 2010-07-05 PY - 2010 SN - 978-0-9541216-6-2 N1 - Geburtsname von Hofmann-Böllinghaus, Anja: Hofmann, A. - Birth name of Hofmann-Böllinghaus, Anja: Hofmann, A. VL - 2 SP - 1139 EP - 1150 CY - London, UK AN - OPUS4-21853 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -