TY - CONF A1 - Krause, Ulrich A1 - Wappler, Mike A1 - Radzewitz, S. A1 - Ferrero, Fabio T1 - On the minimum ignition temperature of dust clouds T2 - 6th International Symposium on hazards, prevention, and mitigation of industrial explosions CY - Halifax, Canada DA - 2006-08-27 KW - Dust explosions KW - Ignition KW - Hot surfaces KW - Minimum ignition temperature PY - 2006 VL - 1 SP - 68 EP - 76 PB - Dalhousie University CY - Halifax AN - OPUS4-12787 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Meyer-Scherf, Ronald A1 - Kluge, Martin A1 - Ferrero, Fabio A1 - Grasse, Dennis ED - Beyer, M. ED - Stolz, T. T1 - Zündung zerfallsfähiger Gase wie Acetylen und Tetrafluorethen durch adiabate Kompression N2 - Die adiabate Kompression stellt insbesondere für zerfallsfähige Gase eine potentielle Zündquelle sowohl bei Herstellungsprozessen als auch beim Umgang in weiter-verarbeitenden Betrieben oder beim Endnutzer dar. Unter bestimmten Bedingungen kann hier eine explosionsartige Zerfallsreaktion auch in Abwesenheit eines Oxidators initiiert werden. Zur systematischen Untersuchung des Zündverhaltens von Zerfallsreaktionen wurde eine Rohrapparatur mit einem schnell öffnenden Kugelhahn aufgebaut, um praxisnahe Vorgänge darstellen zu können. Am Beispiel Tetrafluorethen (TFE) wurden umfangreiche Untersuchungen mit unterschiedlichen Rohrdurchmessern und –längen durchgeführt. Neben der Kompression von homogenen Gasphasen wurden außerdem Kompressionsvorgänge von heterogenen Gasen durchgeführt. Dabei war das Gas im Niederdruckteil unterschiedlich zum Gas im Hochdruckteil. Für den Hochdruckteil wurde Stickstoff, Acetylen und TFE verwendet. Im Niederdruckteil kamen TFE, Stickstoff und Luft zum Einsatz. Zudem wurden das Kompressionsverhältnis sowie die Absolutdrücke im Hochdruck- und Kompressionsteil variiert. Für TFE wurde ein Druckbereich bis 30 bar absolut untersucht. Versuche mit Acetylen wurden zur apparativen Validierung durchgeführt. Es zeigte sich, dass in der verwendeten Apparatur reproduzierbare Zündvorgänge nur im Bereich sehr enger Anfangsparameter möglich sind. Die Kompression von Luft durch ein zerfallsfähiges Gas stellt dabei den sicherheitstechnisch kritischsten Fall dar. T2 - 13. BAM-PTB-Kolloquium zur chemischen und physikalischen Sicherheitstechnik CY - Braunschweig, Germany DA - 18.06.2013 PY - 2013 SN - 978-3-95606-062-5 SN - 1868-5838 N1 - Geburtsname von Meyer-Scherf, Ronald: Meyer, R. - Birth name of Meyer-Scherf, Ronald: Meyer, R. SP - 1 EP - 10 AN - OPUS4-29021 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zeps, Robert A1 - Ferrero, Fabio A1 - Kluge, Martin A1 - Schröder, Volkmar A1 - Spoormaker, T. T1 - Experimental investigation on the self-heating and decomposition of tetrafluoroethylene in a 100-dm³-reactor N2 - In the industry there is a lack of data on the Minimum Ignition Temperature of decomposition of tetrafluoroethylene in industrial sized equipment. In order to determine the Minimum Ignition Temperature of Decomposition of tetrafluoroethylene in large scale vessels, a facility was designed and constructed. Tests were carried out in a cylindrical reactor with a volume of 100 dm³ with initial pressures of 5 and 10 bar(a). In agreement with previous experiments with small scale cylindrical vessels, the Minimum Ignition Temperature of Decomposition of tetrafluoroethylene was observed to decrease with the initial pressure. The current paper describes the test setup and summarizes the experimental results achieved. The effect of the reactor adjustment (vertical or horizontal) is discussed. Moreover, simplified equations from the Semenov thermal explosion theory are used to attempt extrapolations of previous and current data on the Minimum Ignition Temperature of Decomposition of tetrafluoroethylene to other initial pressures and vessel volumes. T2 - Hazards XXIII Symposium CY - Southport, UK DA - 12.11.2012 KW - Tetrafluoroethylene KW - Self-heating KW - Large-scale reactor PY - 2012 SN - 978-0-85295-557-4 N1 - Serientitel: Symposium Series – Series title: Symposium Series N1 - Geburtsname von Kluge, Martin: Beckmann-Kluge, M. - Birth name of Kluge, Martin: Beckmann-Kluge, M. VL - 158 IS - Paper 08 SP - 48 EP - 55 AN - OPUS4-27056 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ferrero, Fabio A1 - Meyer-Scherf, Ronald A1 - Kluge, Martin A1 - Schröder, Volkmar T1 - A parametric study of shock wave simulations with help of COMSOL multiphysics N2 - Adiabatic compression of gases can work as an ignition source and is still one of the main causes of accidents in chemical plants processing tetrafluoroethylene (Reza and Christiansen, 2007). The ignition of tetrafluoroethylene induced by adiabatic compression has been studied experimentally with a setup which allowed for the rapid opening of a high speed valve connecting two portions of a pipeline at different initial pressures. Due to the fast opening time and to the high pressure difference, a shock wave in the pipeline was generated. The propagation of the shock wave and its reflection at the end of the pipeline caused pressure and temperature increase. This led to some ignitions in the experiments performed. Nonetheless, in some test an ignition was not achieved, even if this was expected according to the theoretical temperatures predicted by the Rankine-Hugoniot equations. In order to understand the discrepancy between the experimental results and the theoretical predictions, shock wave simulations have been carried out with COMSOL Multiphysics. The 'High Mach Flow' interface was used, since it solves the heat and impulse equations for fast flows. Figure 1 and Figure 2 show, respectively, the velocity and temperature distribution over time for a simulation in a 0.2 m pipeline of 20 mm in diameter with the following settings: - high pressure section: nitrogen initially at 20 bar; - low pressure section: nitrogen initially at 1 bar; - initial temperature of the system: 20 °C; - adiabatic walls with slip condition for the flow; - laminar flow. As from Figure 1 and Figure 2 the shock wave generation and propagation has been properly computed and the physical properties of the shock wave reflected the prediction of the Rankine-Hugoniot equation. Nonetheless, divergence problem occurred when trying to add turbulence to the system and strange temperature and profiles after the shock wave reflection were achieved if the no slip condition at the walls was chosen. Despite these limitations, it was possible to perform a parametric study and to analyze the effect of the pipe diameter and length on the shock wave evolution. Here simulations with constant wall temperature were carried out, in order to account for the heat losses to the pipe surroundings. Figure 3 shows that the temperature of the reflected wave is maintained for a longer time, if the pipe diameter is larger, due to minor heat losses. On the other hand, Figure 4 shows that higher average temperatures are achieved and maintained for a longer time if the pipe length increases. These results suggest that in the experiments performed by Meyer (2009) the pipe geometry was probably not optimal for the achievement/conservation of high temperatures and might explain the difficulty in inducing ignitions by adiabatic compression. T2 - COMSOL Conference 2012 CY - Milan, Italy DA - 2012-10-10 KW - Adiabatic compression KW - Shock wave KW - Numerical simulation PY - 2012 SN - 978-0-9839688-7-0 N1 - Geburtsname von Kluge, Martin: Beckmann-Kluge, M. - Birth name of Kluge, Martin: Beckmann-Kluge, M. N1 - Geburtsname von Meyer-Scherf, Ronald: Meyer, R. - Birth name of Meyer-Scherf, Ronald: Meyer, R. SP - 1 EP - 6 AN - OPUS4-26785 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ferrero, Fabio A1 - Zeps, Robert A1 - Kluge, Martin A1 - Schröder, Volkmar A1 - Spoormaker, T. ED - Pierucci, S. ED - Klemes, J.J. ED - De Rademaeker, E. ED - Fabiano, B. ED - Buratti, S.S. T1 - The explosive decomposition of tetrafluoroethylene: large scale tests and simulations N2 - There is a lack of data on the self-ignition behaviour of tetrafluoroethylene (TFE) in industrial sized equipment. In order to assess the tendency of TFE for decomposition in large scale vessels, , a facility was designed and constructed. Tests were carried out in a cylindrical reactor with a volume of 100 L with initial pressures of 5 and 10 bar(a). The effect of the reactor adjustment (vertical or horizontal) was taken into account. The current work describes the test set up and summarizes the experimental results achieved. Furthermore, this paper reports on a numerical model for the prediction of the self -heating of TFE in closed vessels, which was previously developed for small scale reactors and has been here validated for larger dimensions with the experiments performed in the new facility. T2 - 14th International symposium on loss prevention and safety promotion in the process industries CY - Florence, Italy DA - 12.05.2013 KW - Tetrafluoroethylene KW - Self-heating KW - Large-scale reactor KW - Numerical simulation PY - 2013 SN - 978-88-95608-22-8 SN - 1974-9791 N1 - Serientitel: Chemical engineering transactions – Series title: Chemical engineering transactions IS - 31 SP - 1 EP - 6(?) PB - AIDIC, Associazione Italiana di Ingegneria Chimica CY - Milano AN - OPUS4-28549 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ferrero, Fabio A1 - Kluge, Martin A1 - Zeps, Robert T1 - Simulation and experimental determination of the self-ignition of tetrafluoroethylene in a 100-dm³-autoclave N2 - The main industrial application of tetrafluoroethylene (TFE, Chemical formula C2F4) is as monomer in the production of polytetrafluoroethylene (PTFE), sold under various brand names, like Teflon® resin by DuPont. The process leading to the formation of PTFE is a Polymerisation, which normally occurs in large reactors as a liquid phase reaction. T2 - 11. Fachtagung Anlagen-, Arbeits- und Umweltsicherheit CY - Köthen, Germany DA - 07.11.2013 PY - 2013 SN - 978-3-86011-058-4 IS - P-15 SP - 1 EP - 7 AN - OPUS4-30026 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ferrero, Fabio A1 - Kluge, Martin A1 - Schröder, Volkmar T1 - Numerical analysis of the effect of the electrode distance during the determination of the flammability limits of gases N2 - COMSOL Multiphysics® was used as a tool for the better understanding of the evolution of flow patterns during the induced ignition of gases. A simplified model was developed for the scope, by coupling the weakly compressible Navier Stokes module and the convection and conduction module. The current paper presents the results of the performed simulations. T2 - COMSOL Conference 2011 CY - Ludwigsburg, Germany DA - 26.10.2011 KW - Spark ignition KW - Gas flow KW - Temperature PY - 2011 SN - 978-0-9839688-0-1 N1 - Geburtsname von Kluge, Martin: Beckmann-Kluge, M. - Birth name of Kluge, Martin: Beckmann-Kluge, M. SP - 1 EP - 7 CY - Stuttgart AN - OPUS4-24700 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kluge, Martin A1 - Ferrero, Fabio A1 - Schröder, Volkmar A1 - Acikalin, Hatice Aydan A1 - Steinbach, J. T1 - Improvements in the modeling of the self ignition of tetrafluoroethylene N2 - In order to prevent incidents in the industrial production of Teflon® from Tetrafluoroethylene (TFE), the safety related aspects of the self-heating process of TFE must be taken into account. Simulations of this self heating process were performed with COMSOL Reaction Engineering Lab® and COMSOL® COMSOL Multiphysics®. A complex reaction net was employed, resulting in a model allows for a good agreement with experimentally achieved results. T2 - COMSOL Conference 2010 CY - Paris, France DA - 2010-11-17 KW - Heating KW - Free convection KW - Reactive flow KW - Gas reaction KW - Self ignition PY - 2010 N1 - Geburtsname von Kluge, Martin: Beckmann-Kluge, M. - Birth name of Kluge, Martin: Beckmann-Kluge, M. SP - 1 EP - 7 AN - OPUS4-24174 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kluge, Martin A1 - Ferrero, Fabio A1 - Zeps, Robert A1 - Kreißig, Michael A1 - Steinhübel, Marco T1 - Untersuchung des Zündverhaltens von Tetrafluorethylen/Luft-Gemischen durch Kompressionsvorgänge im Pilot- und Industriemaßstab N2 - Die adiabate Kompression stellt insbesondere für zerfallsfähige Gase eine potentielle Zündquelle sowohl bei Herstellungsprozessen als auch beim Umgang in weiterverarbeitenden Betrieben oder beim Endnutzer dar. So kam es in der Vergangenheit etwa in TFE-verarbeitenden Anlagen wiederholt zu Störfällen durch Adiabate Kompressionsvorgänge des Monomers. Unter dem Begriff „zerfallsfähige Gase“ oder auch „chemisch-instabile Gase“ versteht man Gase, bei denen es auch in Abwesenheit eines Oxidators nach einer Zündung zu einem explosionsartigem Reaktionsverlauf kommen kann, wie es etwa beim Tetrafluorethylen (TFE) der Fall ist. Die Zerfallsreaktion von TFE ist in Gleichung dargestellt. Sobald eine Zündquelle die Zerfallsreaktion initiiert, kann diese bei bestimmten Anfangsbedingungen von Druck und Temperatur explosionsartig verlaufen. Die schnelle Reaktionsrate zusammen mit der hohen Exothermie der Reaktion kann zur Bildung von heftigen Explosionen führen, wie sie sonst nur bei Brenngas/Oxidator-Gernischen üblich sind. T2 - 11. Fachtagung Anlagen-, Arbeits- und Umweltsicherheit CY - Köthen, Germany DA - 07.11.2013 PY - 2013 SN - 978-3-86011-058-4 IS - P-14 SP - 1 EP - 6 AN - OPUS4-30027 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ferrero, Fabio A1 - Kluge, Martin A1 - Kreißig, Michael A1 - Schmidtchen, Ulrich A1 - Holtappels, Kai T1 - Prevention of the explosion of acetylene cylinders involved in fire: experiments and simulations N2 - In order to assess the effectiveness of water cooling of acetylene cylinders involved in fire, a total of 13 bonfire tests with 8.9-, 10 and 50-l-cylinders were performed. During the experiments the pressure in the cylinder and the temperature at different locations within the porous material and on the Shell surface as well as the flame temperature were measured. Overall 8 burst tests were performed, in order to determine the times to explosion for the cylinders. Cylinders failed not later than 15 minutes from the ignition of the bonfire, often with generation of a fireball. During the other 5 tests, the fire was extinguished before the expected burst and the cylinder was cooled with water. In 2 of the 5 extinction experiments, the explosion of the cylinder could be prevented. Noticeably, in one case the on-set of the decomposition of acetylene had already been observed, before the cooling was started. In spite of that, the cooling was still effective. The interpretation of the current results and of the data from previous tests with 40-l-cylinder suggests that single acetylene cylinders involved in fire might be saved by cooling, if their pressure does not exceed a value of about 45 bara. The recorded values of pressure and temperature were used to develop and validate a mathematical model for the prediction of the heat transfer in acetylene cylinders during the exposure to fire and the afterward cooling. The predictions agreed well with the experimental results. T2 - 23rd ICDERS 2011 CY - Irvine, CA, USA DA - 24.07.2011 KW - Acetylene KW - Gas cylinders KW - Fire exposure KW - Decomposition PY - 2011 N1 - Geburtsname von Kluge, Martin: Beckmann-Kluge, M. - Birth name of Kluge, Martin: Beckmann-Kluge, M. IS - Paper 132 SP - 1 EP - 6 AN - OPUS4-24153 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zeps, Robert A1 - Askar, Enis A1 - Ferrero, Fabio A1 - Kluge, Martin T1 - Zündtemperatur von Gasen/ Gasgemischen bei erhöhten Anfangsdrücken in Abhängigkeit vom Behältervolumen N2 - Zur Einschätzung der Wirksamkeit einer heißen Oberfläche als Zündquelle für ein Gas oder ein Gasgemisch werden in der Praxis Zündtemperaturen experimentell bestimmt. Die Zündtemperatur gemäß dem europäischen Standardverfahren EN 14522 wird bei Atmosphärendruck bestimmt und ist vor allem dazu geeignet die Wirksamkeit einer heißen Oberfläche als Zündquelle bei einem unerwünschten Stoffaustritt aus einer geschlossenen Anlage einzuschätzen. Eine Aussage bzgl. der der Zündfähigkeit an heißen Oberflächen innerhalb einer geschlossenen Anlage, z. B. in größeren Behältern bei bestimmten Gemischzusammensetzungen und höheren Anfangsdrücken, kann anhand der Zündtemperatur gemäß EN 14522 nicht getroffen werden. Die Bestimmung nach dem europäischen Standard erfolgt in einem offenen System, bei atmosphärischem Druck und in Luft als Oxidationsmittel. T2 - 11. Fachtagung Anlagen-, Arbeits- und Umweltsicherheit CY - Köthen, Germany DA - 07.11.2013 KW - Sicherheitstechnische Kenngrößen KW - Chemisch instabile Gase KW - Zerfallsfähige Gase KW - Explosion KW - Ethylenoxid KW - Tetrafluorethylen KW - Acetylen PY - 2013 SN - 978-3-86011-058-4 IS - F-02 SP - 1 EP - 14 AN - OPUS4-29534 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -