TY - GEN A1 - Ferrero, Fabio A1 - Noll, Matthias A1 - Schmidt, Bernd A1 - Malow, Marcus A1 - Schmidt, Martin T1 - Experimentelle und numerische Analyse des Selbstentzündungsverhalten von Holzhalden T2 - 9. Fachtagung "Anlagen-, Arbeits- und Umweltsicherheit" CY - Köthen, Deutschland DA - 2008-11-06 KW - Brandvermeidung KW - Biomasse KW - Lagerung KW - Schüttgüter KW - Selbstentzündung PY - 2008 SN - 978-3-89746-099-7 SP - 1 EP - 21 PB - VDI, Hallescher Bezirksverein CY - Halle AN - OPUS4-18305 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Dreßler, Martin A1 - Röllig, Mathias A1 - Schmidt, Martin A1 - Maturilli, A. A1 - Helbert, J. T1 - Temperature distribution in powder beds during 3D printing N2 - Purpose – This purpose of this paper is to report about the temperature distribution in metal and ceramic powder beds during 3D printing. The differing powders are thoroughly characterized in terms of thermal conductivity, thermal diffusivity, emissivity spectra and density. Design/methodology/approach – The temperature distribution was measured in a 3D printing appliance (Prometal R1) with the help of thin thermocouples (0.25 mm diameter) and thermographic imaging. Temperatures at the powder bed surface as well as at differing powder bed depths were determined. The thermal conductivity, thermal diffusivity and emissivity spectra of the powders were measured as well. Numerical simulation was used to verify the measured temperatures. Findings – The ceramic powder heated up and cooled down more quickly. This finding corresponds well with numerical simulations based on measured values for thermal conductivity and thermal diffusivity as well as emissivity spectra. An observed color change at the metal powder has only little effect on emissivity in the relevant wavelength region. Research limitations/implications – It was found that thermocouple-based temperature measurements at the powder bed surface are difficult and these results should be considered with caution. Practical implications – The results give practitioners valuable information about the transient temperature evolution for two widely used but differing powder systems (metal, ceramic). The paramount importance of powder bed porosity for thermal conductivity was verified. Already small differences in thermal conductivity, thermal diffusivity and hence volumetric heat capacity lead to marked differences in the transient temperature evolution. Originality/value – The paper combines several techniques such as temperature measurements, spectral emissivity measurements, measurements of thermal conductivity and diffusivity and density measurements. The obtained results are put into a numerical model to check the obtained temperature data and the other measured values for consistency. This approach illustrates that determinations of surface temperatures of the powder beds are difficult. KW - Rapid prototypes KW - Printers KW - Heat transfer KW - Powders KW - Ceramics KW - Metals PY - 2010 DO - https://doi.org/10.1108/13552541011065722 SN - 1355-2546 VL - 16 IS - 5 SP - 328 EP - 336 PB - MCB University Press CY - Bradford AN - OPUS4-22002 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schmidt, Martin A1 - Wu, Dejian A1 - Zhao, P. A1 - Tan, X. A1 - Huang, W. A1 - Qianc, X. T1 - Minimum explosion concentrations of coal dusts with CH4/H2/CO below the gas lower explosion limit N2 - A 20-L spherical explosion chamber was used to investigate the explosion characteristics of dust clouds in air with the presence of flammable gas which is lower than its lower explosion limit (LEL). including minimum explosion concentration (MEC) of dust. Explosion pressure (Pex) and explosion pressure rise (dp/dt)ex). Two dust samples (anthracite coal, bituminous coal) and were three flammable gases (CH4, H2 and CO) were tested. Experimental results showed that the explosion of hybrid mixtures occurs when both dust and gas concentrations are lower than the LEL/MEC of the single substances. Meanwhile. all flammable gases with different volume fractions have distinct effects on the MEC. Pex and (dp/dt)ex of the dust samples. With the increase of the flammable gas concentration. either the Pex and (dp/dt)ex increase or the MEC decreases for all the hybrid mixtures of both two dust samples. At the same concentration of coal dusts. the addition of CH4 promotes higher explosion risks than the other two flammable gases. The distribution of (dp/dt)ex is quite different with the restricted area defined by empirical formulas. These results improve our understanding of the explosion behaviour and the explosion risk of hybrid dust-gas mixtures in air. KW - Dust explosions KW - Gas explosions KW - Minimum explosible concentration KW - Lower explosion limit KW - Hybrid mixtures PY - 2020 DO - https://doi.org/10.1016/j.fuel.2019.116401 SN - 0032-5910 VL - 260 SP - UNSP 116401 PB - Elsevier Sci. Ltd. AN - OPUS4-49956 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wu, Dejian A1 - Schmidt, Martin A1 - Tan, X. A1 - Zhao, P. A1 - Huang, W. A1 - Qian, X. T1 - Minimum ignition temperature of carbonaceous dust clouds in air with CH4/H-2/CO below the gas lower explosion limit N2 - Godbert-Greenwald furnace was used to investigate the minimum ignition temperature of dust clouds (MITC) in air with the presence of flammable gas which is lower than its lower explosion limit (LEL). Three flammable gases (CH4, H2 and CO) and three carbonaceous dusts (anthracite coal, bituminous coal and sweet potato starch) were tested. Results showed that all flammable gases have distinct effects on the MITC of the dust samples and volatile matter content of dust plays an important role during the ignition process. Specifically, the MITC of anthracite coal dust decreased from 610 °C to 560 °C, 580 °C and 570 °C with 3% CH4, 3% CO and 2.5% H2, respectively. Moreover, a heterogeneous ignition mechanism model was proposed to verify the equally global ignition characteristic between hybrid anthracite coal-CxHy mixture and bituminous coal. All three gases had an ignorable effect on the MITC of starch dust considering the experimental error. The presence of CO and H2 slightly promoted the ignition of bituminous coal dust, but the addition of CH4 showed a distinct concentration effect on the MITC of bituminous coal: the MITC decreased with 1% CH4 while increased with 2% and 3% CH4. This negative-effect of flammable gases at such low concentrations on ignition temperature of bituminous coal dusts was found for the first time. Furthermore, the presence of the 2nd flammable gas had a smaller effect on the MITC of dust samples with a higher volatile content, resulted from the competition of heterogeneous and homogeneous ignition mechanisms. KW - Dust explosions KW - Gas explosions KW - Minimum ignition temperature KW - Hybrid mixtures PY - 2020 DO - https://doi.org/10.1016/j.fuel.2019.116811 SN - 0016-2361 VL - 264 SP - 116811 PB - Elsevier Ltd. AN - OPUS4-50856 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schmidt, Martin T1 - Der Einfluss des Staubungsverhaltens auf druckentlastete Staubexplosionen T2 - 12. Fachtagung Anlagen-, Arbeits- und Umweltsicherheit CY - Köthen DA - 2015-11-05 PY - 2015 AN - OPUS4-34789 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 - GEN A1 - Dörfel, Ilona A1 - Steinborn, Gabriele A1 - Langner, Jeanette A1 - Krietsch, Arne A1 - Seeger, Stefan A1 - Österle, Werner A1 - Schmidt, Martin A1 - Bresch, Harald T1 - Dossier on titanium dioxide - Part 1/1 - NM 105 N2 - In November 2007, OECD’s Working Party on Manufactured Nanomaterials (WPMN) launched the Sponsorship Programme for the Testing of Manufactured Nanomaterials (hereafter the Testing Programme). The objective was to conduct specific tests, relevant to human health and environmental safety endpoints, on a variety of manufactured nanomaterials (MN). The outcomes of the Testing Programme were intended to assess the applicability of the existing test guidelines1 to nanomaterials, as well as to provide useful information on any intrinsic properties of MNs, which are different from the same bulk material with greater external dimensions. Understanding the properties of NMs is crucial to choose appropriate strategies for hazard identification, risk assessment or risk management measures. The Testing Programme involved delegations from OECD member countries, some non-member economies and other stakeholders. The broad international representation, from a range of delegations enabled the programme to pool expertise and resources without which this programme would not have been possible. KW - Nanomaterial KW - Nanoparticle KW - Sponsorship programme KW - Nano characterization PY - 2015 UR - http://www.oecd.org/env/ehs/nanosafety/dossier-on-silver-nanoparticles-part1-1.htm IS - 54 SP - 27 CY - Paris AN - OPUS4-35430 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schmidt, Martin T1 - Homogenität und Stabilität der Ringversuchs-Probe, Interlabory test 2010/11 DIN EN 15188:2007 T2 - Kolloquium des Arbeitskreises "Brennbare Stäube":Interlabory test 2010/11 DIN EN 15188:2007 - self-ignition temperature" CY - Dresden, Deutschland DA - 2013-01-29 PY - 2013 AN - OPUS4-33533 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schmidt, Martin A1 - Erdt, René A1 - Gödde, M. A1 - Salg, St. A1 - Ittemann, L. T1 - Selbstentzündungsverhalten von Feststoffen: Validierung der Extrapolation von Labortests mithilfe halbtechnischer Versuche bis 1 m3 N2 - Vorgestellt wird ein 2018 gestartetes Projekt zur Überprüfung der Extrapolation von im Labormaßstab ermittelten Selbstentzündungstemperaturen auf technisch relevante Volumina. Für die Ermittlung reaktionskinetischer Daten von Feststoffschüttungen stehen eine Reihe von Untersuchungsmethoden zur Verfügung. Dies sind thermische Analysen wie z. B. die differential scanning calorimetry DSC sowie Mikrokalorimetrie zur hochgenauen Messung von Wärmeströmen, bei denen sehr geringe Probenmengen zum Einsatz kommen. In der Regel wird das Selbstentzündungsverhalten jedoch mithilfe von isoperibolen oder adiabaten Warmlagerungsversuchen beurteilt, hier liegen die Probenvolumina üblicherweise im Bereich von ca. 100 cm3 bis zu einigen Litern. Die Extrapolation über mehrere Größenordnungen auf technische Volumina birgt Unsicherheiten, da mit Zunahme des Lagervolumens veränderte Start- und Randbedingungen vorliegen können. Zudem besteht die Möglichkeit, dass bei in technischen Lagern vorherrschenden niedrigen Temperaturen Reaktionen ablaufen, die in Standard- Laborversuchen nicht erfasst werden, aber einen wesentlichen Einfluss auf das Selbstentzündungsverhalten aufweisen können. Hauptziel des Projektes ist es daher, die im Labormaßstab vorhandenen Prüfeinrichtungen durch einen Versuchsstand zur Untersuchung von Probengrößen von bis zu 1000 dm3 zu erweitern, die Eignung (oder Nichteignung) der etablierten Methoden nachzuweisen und im Labormaßstab nicht erfassbare Einflussgrößen zu ermitteln. Zudem sollen anhand der kleinskaligen Tests Entscheidungskriterien abgeleitet werden, ob eine Extrapolation nach den derzeit üblichen Methoden zulässig ist. T2 - 15. BAM-PTB-Kolloquium zur chemischen und physikalischen Sicherheitstechnik CY - Brunswick, Germany DA - 21.05.2019 KW - Selbstentzündung KW - Formalkinetische Daten KW - Halbtechnische Versuche KW - Thermoanalytische Methoden PY - 2020 SN - 0030-834X VL - 130 IS - 1 SP - 9 EP - 18 AN - OPUS4-51285 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lüth, Peter A1 - Uhlig, S. A1 - Frost, K. A1 - Malow, Marcus A1 - Michael-Schulz, Heike A1 - Schmidt, Martin A1 - Zakel, S. T1 - CEQAT-DGHS interlaboratory tests for chemical safety: Validation of laboratory test methods by determining the measurement uncertainty and probability of incorrect classification including so-called “Shark profiles” N2 - Laboratory test results are of vital importance for correctly classifying and labelling chemicals as “hazardous” as defined in the UN Globally Harmonized System (GHS) / EC CLP Regulation or as “dangerous goods” as defined in the UN Recommendations on the Transport of Dangerous Goods. Interlaboratory tests play a decisive role in assessing the reliability of laboratory test results. Interlaboratory tests performed over the last 10 years have examined different laboratory test methods. After analysing the results of these interlaboratory tests, the following conclusions can be drawn: 1. There is a need for improvement and validation for all laboratory test methods examined. 2. To avoid any discrepancy concerning the classification and labelling of chemicals, the use of validated laboratory test methods should be state of the art, with the results accompanied by the measurement uncertainty and (if applicable) the probability of incorrect classification. This paper addresses the probability of correct/incorrect classification (for example, as dangerous goods) on the basis of the measurement deviation obtained from interlaboratory tests performed by the Centre for quality assurance for testing of dangerous goods and hazardous substances (CEQAT-DGHS) to validate laboratory test methods. This paper outlines typical results (e.g. so-called “Shark profiles” – the probability of incorrect classification as a function of the true value estimated from interlaboratory test data) as well as general conclusions and steps to be taken to guarantee that laboratory test results are fit for purpose and of high quality. T2 - 13th International Symposium on Hazards, Prevention and Mitigation of Industrial Explosions (ISHPMIE 2020) CY - Braunschweig, Germany DA - 27.07.2020 KW - Dangerous goods KW - Hazardous substances KW - Interlaboratory test KW - Test method KW - Validation KW - Quality assurance KW - Measurement uncertainty KW - Incorrect classification KW - Shark profile PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-515376 UR - https://oar.ptb.de/files/download/5f3e662f4c93901010006dbf DO - https://doi.org/10.7795/810.20200724 VL - 2020 SP - 50 EP - 61 PB - Open Access Repository der Physikalisch-Technischen Bundesanstalt (PTB-OAR) CY - Braunschweig AN - OPUS4-51537 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wu, W. A1 - Wei, A. A1 - Huang, W. A1 - Zhao, Peng A1 - Schmidt, Martin A1 - Krause, Ulrich A1 - Wu, Dejian T1 - Experimental and theoretical study on the inhibition effect of CO2/N2 blends on the ignition behavior of carbonaceous dust clouds N2 - Gaseous inhibitors are used in many industries for the explosion prevention of combustible dusts, mitigating the potential hazard to humans, properties and environments. This work experimentally and theoretically studied the inerting effect of gaseous inhibitors on the ignition process of dust clouds in O2/N2/CO2 atmospheres, with an emphasis on the role of the CO2/N2 ratio. 10 different combustible carbonaceous dusts were selected, including grain dust, biomass dust and coal dust. Experimental results showed that the inhibition effect of CO2/N2 is closely related to the ignition mechanism of dust clouds. Specifically, a higher ratio of CO2/N2 yields a stronger inhibition effect on the ignition process of dust samples with relatively low volatile matter contents predominated by heterogeneous ignition. In addition, two novel steady-state ignition mechanism models were developed to interpret the experimental observations. Maxwell-Stefan equations were used to describe the diffusivity in the ternary O2/N2/CO2 gas mixtures. The analytical results were in good agreement with the experimental data of the minimum ignition temperature of dust cloud (MITC) in oxygen-lean atmospheres. The mechanism modelling can be used to estimate the critical ignition temperature of all carbonaceous dust clouds with a wide range of volatile matter content under different inert atmospheres, which will provide a reference for the explosion hazard assessment of dust posed by a hot surface in the process industries. KW - CO2/N2 ratio KW - Inerting effect KW - Volatile matter content KW - MITC KW - Mechanism model PY - 2021 DO - https://doi.org/10.1016/j.psep.2021.07.005 SN - 0957-5820 VL - 153 SP - 1 EP - 10 PB - Elsevier B.V. AN - OPUS4-53662 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wu, Dejian A1 - Tan, X. A1 - Wei, A. A1 - Duan, Q. A1 - Huang, W. A1 - Schmidt, Martin T1 - Ignition temperature and mechanism of carbonaceous dust clouds: The roles of volatile matter, CH4 addition, O2 mole fraction and diluent gas N2 - Minimum ignition temperature of dust clouds (MITC) was studied experimentally and theoretically in different atmospheres. Three carbonaceous dusts were tested in both air and O2/CO2 atmospheres with CH4 mole fraction from 0 to 2%. Results showed that the ignition risk of the three dusts significantly increases (decrease of MITC by ~100 ℃) with increasing XO2 from 21% to 50%, but significantly decreases replacing N2 in air with CO2. The inhibition effect of CO2 on MITCs could be diminished by increasing XO2 or adding CH4. The addition of small amount of CH4 has different effects on the MITCs of different dust samples, following the opposite order of volatile matter content: anthracite>bituminous coal>starch. Two modified steady-state ignition models, considering the density of mixture gas and dust cloud, XO2 and its diffusivity, were developed to interpret the experimental observations. The analysis revealed that the global heterogeneous ignition model suits well for the hybrid mixtures of anthracite or bituminous coal dusts. In contrast, the proposed global homogeneous ignition model was found to be only valid for the pure starch dust, and the extra CH4 addition could strongly affect the ignition process of starch, particularly in O2/CO2 atmospheres with higher XO2. KW - Dust explosions KW - Gas explosions KW - Minimum ignition temperature KW - Hybrid mixtures PY - 2021 DO - https://doi.org/10.1016/j.jhazmat.2020.124189 SN - 0304-3894 SN - 1873-3336 VL - 405 SP - 1 EP - 10 PB - Elsevier CY - Amsterdam AN - OPUS4-53838 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zhao, P. A1 - Schmidt, Martin A1 - Krause, U. A1 - Duan, Q. A1 - Krietsch, Arne A1 - Wu, Dejian T1 - Experimental study on the minimum explosion concentration of anthracite dust: The roles of O2 mole fraction, inert gas and CH4 addition N2 - The explosion characteristics of anthracite coal dust with/without small amount of CH4 (1.14 vol %) were investigated by using a 20 L spherical explosion apparatus with an emphasis on the roles of oxygen mole fraction and inert gas. Two methods based on overpressure and combustion duration time were used to determine the minimum explosion concentration (MEC) or the lower explosion limit (LEL) of the pure anthracite coal dust and the hybrid coal-methane mixtures, respectively. The experiment results showed that increasing oxygen mole fraction increases the explosion risk of coal dust: with increasing oxygen mole fraction, the explosion pressure (Pex) and the rate of explosion pressure rise ((dp/dt)ex)) increase, while MEC decreases. The explosion risk of anthracite dust was found to be lower after replacing N2 with CO2, suggesting that CO2 has a better inhibition effect on explosion mainly due to its higher specific heat. However, the addition of 1.14% CH4 moderates the inhibition effect of CO2 and the promotion effect of O2 on anthracite dust explosion for some extent, increasing explosion severity and reducing the MEC of anthracite dust. For hybrid anthracite/CH4 mixture explosions, Barknecht’s curve was found to be more accurate and conservative than Chatelier’s line, but neither are sufficient from the safety considerations. The experimental results provide a certain help for the explosion prevention and suppression in carbonaceous dust industries. KW - Lower explosion limit KW - Minimun explosion concentration KW - Explosion charasteristics KW - Hybrid mixture KW - Explosion regimes PY - 2021 DO - https://doi.org/10.1016/j.jlp.2021.104490 VL - 2021 SP - 1 EP - 10 PB - Elsevier Ltd. ET - 71 AN - OPUS4-54074 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schmidt, Martin A1 - Erdt, René A1 - Gödde, M. A1 - Salg, St. T1 - Validierung der Extrapolation von Labortests mit Hilfe halbtechnischer Versuche bis 1 m3 und thermoanalytischer Methoden N2 - Zur Bestimmung der reaktionskinetischen Daten von Schüttgütern und iur Vorhersage des Selbstentzündungsverhaltens großer.Lager kommen verschiedene Analysemethoden zum Einsatz. Dabei handelt es sich .um thermische Verfahren wie die Differential-Scanning- Kalorimetrie OS(. die simultane Thermoanalyse STA sowie die Mikrokalorimetrie zur hochpräzisen Messung von Wärmeströmen. Für die oben genannten Methoden werden sehr kleine Probenmengen verwendet. In der Regel wird das Selbstentzündungsverhalten jedoch mit Hilfe von isoperibolen oder adiabatischen Warmlagerungsversuchen ermittelt: die Probenvolumina liegen hier meist im Bereich von ca. 100 cm3 bis zu mehreren Litern. Die Extrapolation auf technisch relevante Volumina birgt jedoch erhebliche Unsicherheiten. Diese Unsicherheiten zu identifizieren und zu reduzieren ist das Hauptziel eines 2018 gestarteten Forschungsprojekts. Dies soll in erster Linie durch den Aufbau eines Versuchsstandes zur Untersuchung von Probengrößen von bis zu. 1000 dm 3 geschehen. Sowohl Warmlagerungsversucl1e im Labormaßstab als auch thermoanalytische Verfahren. die mit Hilfe verschiedener Methoden ausgewertet werden. lassen, einzeln betrachtet. häufig nur bedingt zuverlässige Aussagen über das Selbstentzündungsverhalten von großen Schüttgütern zu. Es werden komplette Versuchsreihen mit allen genannten Prüfverfahren vorgestellt und Aussagen zur Anwendbarkeit der Extrapolationsmethoden diskutiert. T2 - VDI-Fachtagung "Sichere Handhabung brennbarer Stäube 2020" CY - Online meeting DA - 04.11.2020 KW - Selbstentzündung KW - Kinetische Daten KW - Halbtechnische Versuche KW - Thermoanalytische Methoden PY - 2020 SN - 978-3-18-092376-5 SP - 17 EP - 36 AN - OPUS4-52443 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wu, Dejian A1 - Schmidt, Martin A1 - Huang, W. A1 - Wei, A. A1 - Krause, U. A1 - Wu, W. T1 - Inhibition effect of N2/CO2 blends on the minimum explosion concentration of agriculture and coal dusts N2 - Minimum explosion concentration (MEC) of three agriculture dusts and two coal dusts was studied via a 20-L explosion chamber to reveal the role of gaseous inhibitors. Both active method (CO2 diluting air) and passive method (CO2 replacing O2) were used. The TG and DTG thermal analysis tests were conducted to study the pyrolysis and combustion characteristics of dust samples. An alternative explosion criterion based on combustion duration time was used to determine MEC, and compared with the standardized overpressure method. Under 10-kJ ignition condition, as oxygen mole fraction (XO2) decreased from 21% to 10%, MEC of agriculture dusts and coal dusts respectively increased by around 5 times and 2 times. The active inerting method with a lower N2/CO2 ratio was found to have a better suppression effect on the explosion of the five carbonaceous dusts because the blend has a higher specific heat and a lower oxygen diffusion rate. KW - CO2/N2 ratio KW - Explosion criterion KW - Combustion kinetics KW - Inerting effect KW - Explosion characteristics PY - 2022 DO - https://doi.org/10.1016/j.powtec.2022.117195 SN - 0032-5910 VL - 399 SP - 1 EP - 12 PB - Elsevier B.V. AN - OPUS4-55013 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schmidt, Martin A1 - Gödde, M. A1 - Salg, S. A1 - Erdt, René T1 - Self-ignition Behaviour of Bulk Materials: How Reliable is the Extrapolation of Laboratory Tests? N2 - The self-ignition behaviour of bulks is usually determined with the aid of isoperibolic or adiabatic hot storage tests; the sample volumes here are typically in the range of approx. 100 cm³ to several litres. The extrapolation to technically relevant volumes holds, however, considerable uncertainties. To reduce these uncertainties, a test stand was set up that allows to investigation sample sizes of up to 1000 dm³. These allow the study of selfignition behavior closer to the conditions that prevail in practice. The suitability (or unsuitability) of the established methods (including dangerous goods classification tests) were to be demonstrated and influencing variables that cannot be measured on a laboratory scale were to be determined. In addition, various analytical methods were used for the determination of reaction kinetic data of solid bulk materials and to predict the self-ignition behaviour of large storages. These are thermal analyses such as differential scanning calorimetry DSC, simultaneous thermal analysis STA as well as microcalorimetry for highprecision measurement of heat flows. Complete test series using all mentioned test methods will be presented for crosslinked polyvinyl-pyrrolidone (PVP) and conclusions regarding the applicability of the extrapolation methods will be discussed. Hot storage tests up to semi-industrial scale and their combination with various thermoanalytical methods allow a much more precise prediction of the self-ignition behaviour of large bulks. A further promising approach to estimate their heat release rates, and hence, the risk of self-ignition under technical conditions, is the use of microcalorimetric methods. T2 - Loss Prevention 2022 CY - Prag, Czechia DA - 05.06.2022 KW - Self-ignition KW - Kinetic data KW - Semi-technical tests KW - Thermoanalytical methods PY - 2022 SN - 978-88-95608-88-4 DO - https://doi.org/10.3303/CET2290049 SN - 2283-9216 VL - 90 SP - 289 EP - 294 PB - AIDIC AN - OPUS4-55079 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schmidt, Martin A1 - Erdt, René A1 - Gödde, M. A1 - Salg, S. T1 - Self-ignition Behaviour of Bulk Materials: How Reliable is the Extrapolation of Laboratory Tests? N2 - The self-ignition behaviour of bulks is usually determined with the aid of isoperibolic or adiabatic hot storage tests; the sample volumes here are typically in the range of approx. 100 cm³ to several litres. The extrapolation to technically relevant volumes holds, however, considerable uncertainties. To reduce these uncertainties, a test stand was set up that allows to investigation sample sizes of up to 1000 dm³. These allow the study of selfignition behavior closer to the conditions that prevail in practice. The suitability (or unsuitability) of the established methods (including dangerous goods classification tests) were to be demonstrated and influencing variables that cannot be measured on a laboratory scale were to be determined. In addition, various analytical methods were used for the determination of reaction kinetic data of solid bulk materials and to predict the self-ignition behaviour of large storages. These are thermal analyses such as differential scanning calorimetry DSC, simultaneous thermal analysis STA as well as microcalorimetry for highprecision measurement of heat flows. Complete test series using all mentioned test methods will be presented for crosslinked polyvinyl-pyrrolidone (PVP) and conclusions regarding the applicability of the extrapolation methods will be discussed. Hot storage tests up to semi-industrial scale and their combination with various thermoanalytical methods allow a much more precise prediction of the self-ignition behaviour of large bulks. A further promising approach to estimate their heat release rates, and hence, the risk of self-ignition under technical conditions, is the use of microcalorimetric methods. T2 - Loss Prevention 2022 CY - Prague, Czech Republic DA - 05.06.2022 KW - Self-ignition KW - Kinetic data KW - Semi-technical tests KW - Thermoanalytical methods PY - 2022 AN - OPUS4-55080 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Wilrich, Cordula A1 - Schröder, Volkmar A1 - Brandes, E. A1 - Schmidt, Martin A1 - Wandrey, Peter-Andreas A1 - Mix, K.-H. A1 - Wehrstedt, Klaus-Dieter A1 - Bender, H. A1 - Stephan, U. A1 - Eberz, A. A1 - Steinbach, J. A1 - Stoessel, F. T1 - Plant and process safety - 2. Hazardous materials and process conditions N2 - "Ullmann's Encyclopedia of Industrial Chemistry" is the benchmark reference in chemistry and chemical and life science engineering, covering inorganic and organic chemicals, advanced materials, pharmaceuticals, polymers and plastics, metals and alloys, biotechnology and biotechnological products, food chemistry, process engineering and unit operations, analytical methods, environmental protection, and much more. The present article is part of the topic collection "Environmental Protection and Industrial Safety". It covers plant and process safety, focusing on hazardous materials and process conditions. KW - Flammable gases and vapors KW - Combustibility of liquids KW - Dust explosions KW - Explosive condensed substances KW - Harmful effects of substances KW - Exothermic and pressure-inducing chemical reactions PY - 2012 SN - 978-3-527-30673-2 DO - https://doi.org/10.1002/14356007.q20_q01 SP - 1 EP - 50 PB - Wiley-VCH CY - Weinheim AN - OPUS4-58108 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schmidt, Martin T1 - Selbstentzündungsverhalten von Holz- und Biokohlen Gefahrguteinstufung sicher? N2 - Mit der Abkehr von der Nutzung fossiler Rohstoffe rücken regenerative Energieträger immer weiter in den Focus. Neben klassischen Holzkohlen werden verstärkt so genannte Biokohlen produziert. Dieser Begriff findet Verwendung für mit Hilfe verschiedener Verfahren karbonisierte pflanzliche, tierische oder mikrobielle Ausgangsstoffe. Diese Kohlen werden zum Teil über weite Strecken zum Bestimmungsort transportiert (Überseetransporte) oder vor Verwendung für längere Zeit gelagert. Häufig zeigen diese Kohlen ein kritisches Selbstentzündungsverhalten, wobei Einstufungstests (UN N.4 Test) versagen können. Ein negatives Testergebnis des UN N.4 Tests führte dabei in der Vergangenheit zur Nichteinstufung als selbsterhitzungsfähiger Stoff; in der Praxis entzündeten sich aber bereits vergleichsweise kleine Schüttungen (einige m³), z. B. beim Seetransport in Containern. Der Artikel geht auf dieses Problem ein, stellt Prüfverfahren vor und gibt Empfehlungen für sicheren Transport und Lagerung. T2 - VDI Fachtagung "Sichere Handhabung brennbarer Stäube CY - Nürnberg, Germany DA - 25.10.2023 KW - Biokohle KW - Selbstentzündung KW - Gefahrguteinstufung PY - 2023 AN - OPUS4-59597 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Schmidt, Martin T1 - Selbstentzündungsverhalten von Biokohlen - Gefahrguteinstufung immer sicher? N2 - Mit der Abkehr von der Nutzung fossiler Rohstoffe rücken regenerative Energieträger immer weiter in den Focus. Neben klassischen Holzkohlen werden verstärkt so genannte Biokohlen produziert. Dieser Begriff findet Verwendung für mit Hilfe verschiedener Verfahren karbonisierte pflanzliche, tierische oder mikrobielle Ausgangsstoffe. Diese Kohlen werden zum Teil über weite Strecken zum Bestimmungsort transportiert (Überseetransporte) oder vor Verwendung für längere Zeit gelagert. Häufig zeigen diese Kohlen ein kritisches Selbstentzündungsverhalten, wobei Einstufungstests (UN N.4 Test) versagen können. Ein negatives Testergebnis des UN N.4 Tests führte dabei in der Vergangenheit zur Nichteinstufung als selbsterhitzungsfähiger Stoff; in der Praxis entzündeten sich aber bereits vergleichsweise kleine Schüttungen (einige m³), z. B. beim Seetransport in Containern. Der Artikel geht auf dieses Problem ein, stellt Prüfverfahren vor und gibt Empfehlungen für sicheren Transport und Lagerung. KW - Biokohlen KW - Selbstentzündung KW - Gefahrguteinstufung PY - 2023 SN - 978-3-18-092424-3 SN - 978-3-18-092424-9 SN - 0083-5560 SP - 143 EP - 153 PB - VDI Verlag GmbH CY - Düsseldorf AN - OPUS4-59598 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schmidt, Martin T1 - Holzkohlen im Seeverkehr - Selbstentzündung vermeiden, sichere Beförderungsbedingungen schaffen N2 - Mit der Abkehr von der Nutzung fossiler Rohstoffe rücken regenerative Energieträger immer weiter in den Focus. Neben klassischen Holz- und Pflanzenkohlen werden verstärkt so genannte Biokohlen produziert. Dieser Begriff findet Verwendung für mit Hilfe verschiedener Verfahren karbonisierte pflanzliche, tierische oder mikrobielle Ausgangsstoffe. Diese Kohlen werden zum Teil über weite Strecken zum Bestimmungsort transportiert (Überseetransporte) oder vor Verwendung für längere Zeit gelagert. Häufig zeigen diese Kohlen ein kritisches Selbstentzündungsverhalten, wobei Einstufungstests (UN N.4 Test) versagen können. Ein negatives Testergebnis des UN N.4 Tests führte dabei in der Vergangenheit zur Nichteinstufung als selbsterhitzungsfähiger Stoff; in der Praxis entzündeten sich aber bereits vergleichsweise kleine Schüttungen (einige m³), z. B. beim Seetransport in Containern. Ergebnisse eines Projektes zur systematischen Untersuchung verschiedener Pflanzenkohlen werden vorgestellt. T2 - Internationale Gefahrgut-Tage CY - Hamburg, Germany DA - 26.02.2024 KW - Holzkohlen KW - Pflanzenkohlen KW - Selbstentzündung KW - Gefahrguteinstufung KW - Schiffsbrände PY - 2024 AN - OPUS4-59599 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -