TY - CONF A1 - Schmidt, Martin T1 - Ringversuch Messunsicherheit DIN EN 15188/Ergebnisse INS Projekt "Explodierender Draht" als alternative Zündquelle für die 20-l-Kugel T2 - 61. Industriearbeitskreis "Brennbare Stäube" CY - Ludwigshafen, Deutschland DA - 2014-06-24 PY - 2014 AN - OPUS4-32115 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schmidt, Martin A1 - Scheid, Marc T1 - Validation of the New Ignition Source "Exploding Wire" for Dust Explosion Testing in the 20-l-Sphere T2 - Hazards 24 CY - Edinburgh, Scotland DA - 2014-05-07 PY - 2014 AN - OPUS4-30690 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krietsch, Arne A1 - Scheid, Marc A1 - Schmidt, Martin A1 - Krause, U. T1 - Explosion behaviour of metallic nano powders N2 - This paper describes experiences and results of experiments with several metallic dusts within the nanometer range. The nano dusts (aluminium, iron, zinc, titanium and copper) were tested in 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 already introduced in earlier papers by the authors. It 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). Furthermore the influence of passivation on explosion behaviour is investigated and additional tests with deposited dust were carried out to describe the burning behaviour of all dusts. For a better characterisation all samples were tested with a simultaneous thermal analysis (STA). To minimise the influence of oxidation all samples were handled at inert conditions until shortly before ignition or start of the test respectively. T2 - X ISHPMIE - 10th International symposium on hazards, prevention, and mitigation of industrial explosions CY - Bergen, Norway DA - 10.06.2014 KW - Dust explosion KW - Nano dust KW - Ignition KW - Explosion protection PY - 2014 SN - 978-82-999683-0-0 SP - 1475 EP - 1485 AN - OPUS4-30938 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schmidt, Martin T1 - Self-ignition of bulk solids: laboratory tests - simulations - reality? T2 - Fire Science Workshop CY - Berlin, Germany DA - 2013-11-29 PY - 2013 AN - OPUS4-30978 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 - JOUR A1 - Everard, C.D. A1 - Schmidt, Martin A1 - McDonnell, K.P. A1 - Finnan, J. T1 - Heating processes during storage of Miscanthus chip piles and numerical simulations to predict self-ignition N2 - Miscanthus x Giganteus (Miscanthus) energy crop was examined at laboratory scale to assess its self-heating and self-ignition risks during storage. Chipped Miscanthus (18 mm) from February and March harvests, in 2012, were assessed as well as ground Miscanthus (3 mm) from the March harvest. February and March crops had moisture contents of 41.6 and 20.2%, respectively. Self-ignition temperatures were independent of moisture although moisture did affect the time from the beginning of storage until storage temperature was reached. Ground Miscanthus had lower self-ignition temperatures than chipped Miscanthus. Isothermal respirometric tests carried out showed increase risk of self-heating in the February crop compared to the March crop due to increased microbial activity. Numerical simulations were used to determine critical enhanced start temperatures, e.g. caused by microbial decomposition, of the stored Miscanthus. Safe storage conditions have been derived from the investigations. The numerical simulations demonstrated that self-ignition was possible in Miscanthus chip piles with a height greater than 6 m if there was significant heat release from microbiological activity. Reliable assessment of self-heating and self-ignition risks in large scale Miscanthus energy crop clamps or piles are required to prevent losses due to decomposition and fire damage. KW - Miscanthus x Giganteus KW - Hot storage test KW - Respirometric rates KW - Self-heating KW - Self-ignition KW - Numerical simulations KW - Biomass storage PY - 2014 DO - https://doi.org/10.1016/j.jlp.2014.06.003 SN - 0950-4230 SN - 1873-3352 VL - 30 SP - 188 EP - 196 PB - Butterworth CY - Guildford, Surrey AN - OPUS4-31149 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Krietsch, Arne A1 - Schmidt, Martin A1 - Krause, U. T1 - Brand- und Explosionseigenschaften von nanoskalig hergestellten Stäuben N2 - Nanotechnologie gilt als die Wachstumsbranche der nächsten Jahrzehnte. Nicht zuletzt ist diese Entwicklung den veränderten Eigenschaften der Materialien im Nanometerbereich zuzuschreiben. Das anders geartete Verhalten solcher Stoffe und die daraus ableitbare Unkenntnis über die Interaktion dieser Materialien mit ihrer Umgebung erfordert zur Risikoabschätzung eine intensive Auseinandersetzung mit der Thematik. Aufgrund von Erfahrungen mit Stäuben mit Partikelgrößen im Mikrometerbereich ist bekannt, dass Stoffe mit abnehmender Partikelgröße kritischer einzustufen sind, da ihre Explosionsheftigkeit und Zündempfindlichkeit durch die Zunahme der reaktiven Oberfläche des Staubs zunimmt. Nachfolgend werden Ergebnisse von Versuchen mit nanoskalig hergestellten Metallstäuben präsentiert. Der Fokus dieser Studie lag darauf, möglichst das kritischste Brand- und Explosionsverhalten solcher Stäube zu erfassen. KW - Staubexplosion KW - Nanostäube KW - Sicherheitstechnische Kenngrößen PY - 2014 SN - 2191-0073 VL - 4 IS - 9 SP - 44 EP - 49 PB - Springer-VDI-Verl. CY - Düsseldorf AN - OPUS4-31395 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krietsch, Arne A1 - Scheid, Marc A1 - Schmidt, Martin T1 - Burning and explosion properties of metallic nano powders N2 - This paper describes experiences and results of experiments with several metallic dusts within the nanometer range. The nano dusts (aluminium, .iron, zinc, titanium and copper) were tested in 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 already introduced in earlier papers by the authors. It 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). Furthermore the influence of passivation on explosion behaviour is investigated and additional tests with deposited dust were carried out to describe the burning behaviour of all dusts. For a better characterisation all samples were tested with a simultaneous thermal analysis (STA). To minimise the influence of oxidation all samples were handled at inert conditions until shortly before ignition or start of the test respectively. T2 - Hazards 24 Symposium CY - Edinburgh, UK DA - 07.05.2014 KW - Nano powder KW - Explosion protection KW - Nano materials PY - 2014 SN - 978-0-85295-582-6 N1 - Serientitel: IChemE Symposium Series – Series title: IChemE Symposium Series VL - 159 SP - 1 EP - 9 AN - OPUS4-30903 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schmidt, Martin T1 - Brand- und Explosionsgefahren beim Umgang mit Metallstäuben N2 - Grundlagen des Brand- und Explosionsschutzes mit Schwerpunkt Metallstäube: - Gefahren - Prinzipien des Explosionsschutzes - Ableiten von Schutzmaßnahmen - Bestimmung der Stoffeigenschaften - Umgang mit entsprechenden Datenbanken T2 - DGM-Fortbildungsseminar "Metallpulver Erzeugen - Charakterisieren - Anwenden" CY - Bremen, Germany DA - 30.03.2017 KW - Brandschutz KW - Explosionsschutz KW - Sicherheitstechnische Kenngrößen PY - 2017 AN - OPUS4-39917 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wu, D. A1 - Schmidt, Martin A1 - Huang, X. A1 - Verplaesten, F. T1 - Self-ignition and smoldering characteristics of coal dust accumulations in O2/N2 and O2/CO2 atmospheres N2 - The self-ignition of coal dust deposits and its subsequent smoldering combustion pose a high fire hazard to oxy-fuel power systems which burn fuels using pure oxygen for the sake of carbon capture and storage. The increasing risk of explosion in the gas-phase and self-ignition in the solid-phase for an oxygen enhanced combustion environment has not been well studied yet. In this work, the heterogeneous reactions of a bituminous coal dust are investigated by using a novel hot-basket apparatus with an emphasis on the roles of O2 and diluent gas in chemisorption and smoldering. Experiments show that increasing O2 mole fraction accelerates both self-ignition and the following smoldering combustion. On the other hand, the presence of CO2 increases the ignition temperature and reduces the maximum smoldering temperature. However, the promotion in the fire and explosion risk by elevating O2 mole fraction is substantially stronger than the retardation effected by presence of CO2. The emission-gas measurements show that the CO to CO2 ratio increases significantly after self-ignition, and CH4 counts for 1–8% of the total carbon emission. This research may help improve the understanding of heterogeneous coal combustion and the fire safety in oxy-fuel power systems. KW - Oxy-fuel cobustion KW - Fire hazard KW - FTIR KW - CO/CO2 ratio KW - CH4 PY - 2017 DO - https://doi.org/10.1016/j.proci.2016.08.024 SN - 1540-7489 SN - 1873-2704 VL - 36 IS - 2 SP - 3195 EP - 3202 AN - OPUS4-39927 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schmidt, Martin T1 - Brand- und Explosionsgefahren beim Umgang mit nanoskalig hergestellten Materialien N2 - In vielen Bereichen der Industrie und im verarbeitenden Gewerbe werden eine Vielzahl brennbarer Stäube produziert, verarbeitet, transportiert oder anderweitig verwendet. Die Partikelgröße der Stäube übt einen entscheidenden Einfluss auf deren Brand- und Explosionsverhalten aus. Mit Abnahme der Partikelgröße nehmen die gefährlichen Auswirkungen im Falle einer Explosion sowie die Zündempfindlichkeit zu. Aufgrund besonderer Eigenschaften nanoskaliger Materialien hat die Produktion solcher Stäube mit sehr geringen Primärpartikelgrößen in den letzten Jahren zugenommen. Über das Brand- und Explosionsverhalten solcher Stäube war bis vor wenigen Jahren jedoch kaum bis wenig bekannt. Untersuchungen haben gezeigt, dass nanoskalig hergestellte Stäube im Fall einer Explosion nicht grundsätzlich heftiger reagieren als die kritischsten Mikrostäube. Dennoch reagieren sogenannte Nanostäube mitunter zündempfindlicher als vergleichbare Mikrostäube; vereinzelt wurden höhere Werte für den maximalen Explosionsdruck und zeitlichen Druckanstieg für vergleichbare Stäube mit mikroskaligen Partikeln festgestellt. Für die Praxis ist daher zu beachten, dass zündempfindliche Stäube dementsprechend transportiert und gehandhabt bzw. entsprechende Schutzmaßnahmen ergriffen werden. T2 - Tagung des Sachgebietes "Explosionsschutz" der deutschen gesetzlichen Unfallversicherung CY - Heidelberg, Germany DA - 24.11.2016 KW - Nanoskalige Stäube KW - Explosionseigenschaften KW - Zündverhalten PY - 2016 AN - OPUS4-39112 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schmidt, Martin T1 - Interlaboratory Test 2015 "EN 15188" - Ergebnisse und Schlussfolgerungen N2 - Ergebnisse des Ringversuches "DIN EN 15188: Determination of the spontaneous ignition behaviour of dust acuumulations T2 - Industriearbeitskreis "Brennbare Stäube" CY - Wolfgang-Hanau, Germany DA - 28.06.2016 KW - Selbstentzündung KW - Ringversuch KW - Methodenvalidierung KW - Messunsicherheit PY - 2016 AN - OPUS4-37196 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schmidt, Martin A1 - Wu, D. A1 - Norman, F. A1 - Vanierschot, M. A1 - Verplaetsen, F. A1 - Berghmans, J. A1 - van den Bulck, E. T1 - Numerical investigation on the self-ignition behaviour of coal dust accumulations: The roles of oxygen, diluent gas and dust volume N2 - Self-ignition of coal dust deposits poses a higher risk of fires in oxygen-enriched oxy-fuel combustion systems. In this work, we develop a numerical method, using the commercial software COMSOL Multiphysics, to investigate self-ignition behaviour of coal dust accumulations with a main emphasis on the roles of oxygen, diluent gas and dust volume. A one-step 2nd-order reaction kinetic model considering both coal density and oxygen density is used to estimate reaction rate using the kinetic parameters from previously conducted hot-oven tests. This model is validated to predict the transient temperature and concentration profiles of South African coal dusts until ignition. The computed self-ignition temperatures of dust volumes show a good agreement with experimental results. In addition, it is found that the inhibiting effect of carbon dioxide is comparatively small and oxygen consumption increases dramatically after ignition. Parameter analysis shows that the heating value and kinetic parameters have a comparatively pronounced effect on self-ignition temperature. The model provides a satisfactory explanation for the dependence of self-ignition behaviour on gas atmospheres, thus helping to further understand the fire risk of self-ignition in oxy-fuel combustion systems. KW - Ignition temperature KW - Oxy-fuel combustion KW - Fire safety KW - Self-ignition KW - Numerical simulation PY - 2017 DO - https://doi.org/10.1016/j.fuel.2016.10.063 SN - 0016-2361 SP - 500 EP - 510 AN - OPUS4-37885 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -