TY - CONF A1 - Krietsch, Arne A1 - Gothe, C. A1 - Scheid, Marc A1 - Krause, U. ED - Makhviladze, G. ED - Molkov, V. ED - Bradley, D. ED - Sunderland, P. ED - Tamanini, F. T1 - Determination of explosion behaviour of nano powders with modified 20-L-sphere test N2 - This paper describes a modified experimental setup for the test apparatus 20-L-Sphere (also known as 20-L Siwek Chamber), that enables the test samples to be kept under inert atmospheric conditions nearly until ignition. This setup was designed to allow the determination of safety characteristics of nano powders under most critical circumstances (e.g. minimisation of the influence of oxidation before the test itself). The aim of this modification was to determine, whether or not the current setup and procedures underestimate the explosion violence and ignitability of nano powders. For this purpose, two different methods, the so called inerting method and the modified method (using a special nozzle called mushroom nozzle) are used. Both methods are described in the paper. The work includes experimental results of micrometer dusts to validate the modified method. Moreover first results of nanometer iron and aluminium dusts are presented, which were kept at inert conditions until shortly before the ignition. The tested nano iron was found to react pyrophoric, as soon as it gets in contact with air, while the tested nano aluminium did not generally show such behaviour. Tests with nano aluminium using the inerting method revealed a higher pressure rise in comparison to the standard test procedure. This could suggest a different extent of passivation. To investigate this effect more closely, further testes with more nano powders are required. T2 - ISFEH7 - 7th International seminar on fire & explosion hazards CY - Providence, RI, USA DA - 05.05.2013 KW - Nano material KW - Dust explosion KW - Safety characteristics KW - Nanopowder PY - 2013 SN - 978-981-07-5936-0 SN - 978-981-07-5940-7 U6 - https://doi.org/10.3850/978-981-07-5936-0_13-03 SP - 801 EP - 809 PB - Research publishing AN - OPUS4-28560 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krietsch, Arne A1 - Romahn, T.-M. A1 - Scheid, Marc A1 - Krause, U. ED - Pierucci, S. ED - Klemes, J.J. ED - De Rademaeker, E. ED - Fabiano, B. ED - Buratti, S.S. T1 - Modified setup of 20-L-sphere for the determination of safety characteristics of nano powders N2 - This paper describes a modified experimental setup for the test apparatus 20-L-Sphere (also known as 20-L Siwek Chamber), that enables the test samples to be kept under inert atmospheric conditions nearly until ignition. This setup was designed to allow the determination of safety characteristics of nanopowders under most critical circumstances (e.g. minimisation of the influence of oxidation before the test itself). The aim of this modification was to determine, whether or not the current setup and procedures underestimate the explosion violence and ignitability of nanopowders. The work includes experimental results of micrometer dusts to validate the modified setup. Moreover first results of nanometer iron and Aluminium dusts are presented, which were kept at inert conditions until shortly before the ignition. The tested nano iron was found to react pyrophoric, as soon as it gets in contact with air, while the tested nano Aluminium did not generally show such behaviour. T2 - 14th International symposium on loss prevention and safety promotion in the process industries CY - Florence, Italy DA - 12.05.2013 KW - Dust explosion KW - Nanopowder PY - 2013 SN - 978-88-95608-22-8 U6 - https://doi.org/10.3303/CET1331135 SN - 1974-9791 N1 - Serientitel: Chemical engineering transactions – Series title: Chemical engineering transactions IS - 31 SP - 805 EP - 810 PB - AIDIC, Associazione Italiana di Ingegneria Chimica CY - Milano AN - OPUS4-28561 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 U6 - 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 - Krause, U. A1 - Schmidt, Martin A1 - Wanke, Ch. T1 - Determination of measurement uncertainties in adiabatic hot storage experiments for flammable dusts T2 - 9th International Seminar on Hazars, Pevention and Mitigation of Industrial CY - Kraków, Poland DA - 2012-07-22 PY - 2012 AN - OPUS4-26367 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Löhnert, Andrea A1 - Rabe, Frederik A1 - Knaust, Christian A1 - Krause, U. T1 - Numerical and experimental investigation of fire smoke toxicity T2 - International congress ' Fire computer modeling' CY - Cantabria, Spain DA - 2012-10-18 PY - 2012 SN - 978-84-86116-69-9 SP - 171 EP - 188 AN - OPUS4-27893 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Deubel, Jan A1 - Werrel, Martin A1 - Krüger, Simone A1 - Krause, U. T1 - Experimentelle Untersuchungen zum Einfluss von Brandbeschleuniger auf den Verlauf von Raumbränden T2 - 3. Magdeburger Brand- und Explosionsschutztag / vfdb-Workshop CY - Magdeburg, Germany DA - 2013-03-21 KW - Brandbeschleuniger KW - Raumbrand PY - 2013 SN - 978-3-00-041601-9 SP - 1 EP - 9(?) AN - OPUS4-27989 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Tschirschwitz, Rico A1 - Schröder, Volkmar A1 - Brandes, E. A1 - Krause, U. T1 - Bestimmungsverfahren sicherheitstechnischer Kenngrößen bei nichtatmosphärischen Bedingungen N2 - Es werden die Untersuchungsergebnisse für ein geeignetes Zündkriterium zur Bestimmung von Explosionsgrenzen bei nichtatmosphärischen Bedingungen vorgestellt. Dazu wurden für Anfangsdrücke bis 20 bar Zündversuche an den Explosionsgrenzen von CHL/Luft-, CaHg/Luft-, H2/Luft- und NHs/Luft-Gemischen in einem Autoklav mit Sichtscheibe durchgeführt. In der Auswertung wurden visuelle Zündkriterien und ein Druckschwellenkriterium miteinander verglichen. Weiterhin wurden Untersuchungen zum erforderlichen Mindesvolumen des Explosionsgefäßes in Abhängigkeit des Anfangsdrucks durchgeführt. Dazu wurden jeweils Zündversuche mit demselben Gemisch aus CH4 und Luft bei Anfangsdrücken bis 50 bar in Volumina zwischen 0,2 dm3 und 6,0 dm3 durchgeführt. T2 - 3. Magdeburger Brand- und Explosionsschutztag / vfdb-Workshop CY - Magdeburg, Germany DA - 21.03.2013 KW - Kenngrößen KW - Nichtatmosphärische Bedingungen KW - Zündkriterium PY - 2013 SN - 978-3-00-041601-9 SP - 1 EP - 12 AN - OPUS4-28271 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Sipilä, J. A1 - Auerkari, Pertti A1 - Malmén, Y. A1 - Heikkilä, A.-M. A1 - Vela-Wallenschus, Iris A1 - Krause, U. T1 - Experience and the unexpected:risk and mitigation issues for operating underground storage silos for coal-fired power plant N2 - Observed autoignition events and extinguishing the resulting smouldering fires in an underground storage system of a coal-fired power plant have provided insight into the array of contributing variables, and some experience on quantifying the risk with alternative scenarios of event initiation, progress and potential mitigation. Although the first attempts to quantify the risk suggest high sensitivity to the sequence of action taken after fire alarm, and no similar storage sites really exist, some recommended preventive, corrective and other mitigating activities can be at least partly defined and improved by using the cumulative experience and parallel efforts in other closed or underground storage sites. However, there are also so-called black (or at least grey) swans: unexpected events for which the facility may be poorly prepared for. In the case of the underground storage silos, such an event was experienced when incoming cold coal during a harsh winter season froze the sewer system that normally protects the stored coal from seepage water. With blocked normal bypass, the seepage water found its way to the coal silos and created large clumps of icy coal that blocked the coal conveyors. Although freezing weather is not unusual at high-latitude power plants, the common methods to combat freezing of coal are mainly useful for open storage sites and above-ground transport. Options for mitigation are discussed, as well as the event chain leading to an event that had never previously occurred. The case is discussed from the point of view of options to prepare for rare or unforeseen events. KW - Coal KW - Underground storage KW - Fire KW - Freezing KW - Risk KW - Mitigation PY - 2013 U6 - https://doi.org/10.1080/13669877.2012.729530 SN - 1366-9877 SN - 1466-4461 N1 - Geburtsname von Vela-Wallenschus, Iris: Vela, I. - Birth name of Vela-Wallenschus, Iris: Vela, I. SP - 1 EP - 14 PB - Taylor & Francis CY - London [u.a.] AN - OPUS4-28260 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - Schoßig, Jörg A1 - Schmidt, Martin A1 - Krause, U. T1 - Validierung von formalkinetischen Größen aus der adiabatischen Warmlagerung KW - Selbstentzündung KW - Adiabate Warmlagerung KW - Reaktionskinetik PY - 2011 SP - 1 EP - 57 ET - Abschlussbericht Forschungsvorhaben AN - OPUS4-25012 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Werrel, Martin A1 - Deubel, Jan A1 - Krüger, Simone A1 - Hofmann-Böllinghaus, Anja A1 - Antonatus, E. A1 - Krause, U. A1 - Duerler, F. T1 - Use and benefit of a controlled-atmosphere cone calorimeter N2 - A controlled-atmosphere cone calorimeter that is built by modifying the Standard apparatus with the addition of a controlled-atmosphere chamber offers a time- and cost-saving approach for reaction-to-fire testing in vitiation- and ventilation-controlled atmospheres. Due to the design of the added enclosure no mechanical changes on cone calorimeter’s Standard ductwork are required. This offers some advantages but also important limitations. The design has an open connection between the outlet of the added enclosure and the cone calorimeter’s exhaust hood. Therefore, sufficient ambient air from the laboratory surroundings is drawn into the System to introduce effects which have the potential to affect test results significantly. A procedure which is is suitable to consider physical effects of the ambient air on the calculation of the heat release rate is presented as well as initial results of an application towards toxic potency assessment. Signs for Chemical effects of the ambient air such as post reactions are shown but subject of an ongoing work. T2 - Fire and materials 2013 - 13th International conference and exhibition CY - San Francisco, CA, USA DA - 28.01.2013 KW - Controlled-atmosphere cone calorimeter KW - Heat release rate KW - Oxygen consumption KW - Smoke toxicity PY - 2013 SP - 273 EP - 286 PB - Interscience Communications CY - London, UK AN - OPUS4-27707 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -