TY - JOUR A1 - Kurth, Lutz A1 - Krebs, Holger A1 - Theil, Benjamin A1 - Mücke, Olaf A1 - Lohrer, Christian T1 - Assessment of explosives in squibs N2 - Experiments in this study reveal that the initiating capability ofcommonly used squibs is not high enough to initiate PETN in all cases. The fulfilment of the 'new ’ essential safety requirement 4 as set out in the European directive 2013/29/EU and the categorization of squibs as theatrical pyrotechnic articles (T2) can therefore be justified, as the explosive investigated belongs to quite a sensitive type (Initiation with low Impulse energiespossible). Underwater initiating capability tests according to EN 13763-15 led to meaningful results, showing that squibs are usually unable to initiate a secondary explosive. For a general assessment of the initiating capability of squibs and comparable (theatrical) pyrotechnic articles a threshold ränge of an equivalent initiation capability in grams of PETN on the basis of the performed underwater initiating capability tests was determined. It was found that squibs are generally not capable of initiating secondary explosives if the underwater initiating capability fest showed an equivalent Initiation capability below 0.25 g PETN. As a consequence of this result, the underwater initiating capability fest gives an effective and safer alternative to the experimental confirmation of the ‘new ’ESR 4 by direct contact of the article with the secondary explosive and should then be preferred to it. KW - Squibs KW - ESR 4 KW - PETN KW - Underwater initiating capability KW - EN 13763-15 PY - 2013 SN - 1082-3999 IS - 32 SP - 57 EP - 66 CY - Whitewater, Colo. AN - OPUS4-29660 LA - eng 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 - Douet, Marianne A1 - Lohrer, Christian A1 - Kurth, Lutz A1 - Mücke, Olaf T1 - Safety related behavior of cylindrical shells N2 - The European Standard series EN 16261 consisting of four parts deals with the testing and assessment of display fireworks in order to satisfy the essential safety requirements of the Directive 2007/23/EC which have to be met before placing these articles on the EU market. The current Version of this Standard provides mortar dimension limits to be used for the assessment of burst heights of spherical Shells, but lacks corresponding provisions for cylindrical shells. The aim of this study was threefold: 1. To check whether the requirements for spherical shells would overlap with the ones for cylindrical shells, 2. To compare several test procedures for height measurements with each other to minimize the measurement uncertainty of the effect dimensions, and 3. To evaluate drift distances in order to check whether the current national provisions on safety distances for Professional fireworks displays need adaption during the implementation of the new European directive 2013/29/EU on pyrotechnics in German legislation. For this study, a large number of cylindrical shells was specifically manufactured to guarantee lull control on all relevant constructional aspects. These shells were designed with a smoke tracer and no burst Charge so that they would fall back to the ground in order to investigate their drift distances. Their gross mass corresponded to commercially available display shells, though, consisting of defined inert substances inside the shell. The following Parameters were varied in this study: caliber (75 mm, 100 mm, 150 mm), shell length per caliber (single and double length), lift Charge (hard and soft burst effect), mortar length per caliber (short and long). In total, more than 120 shells were manufactured and tested. Results show a good application of the proposed test procedures regarding the mortar dimensions given in the Standard series for cylindrical shells as well. The following test procedures were part of this study: Radar Doppler System, video grammetric System, universal surveying instruments, and mortar internal pressure measurements. Observed drift distances in relation to the caliber and effect heights are discussed and assessed. T2 - 15th International symposium on fireworks CY - Bordeaux, France DA - 21.09.2015 KW - Radar-Doppler KW - Height measurements KW - Drift effects KW - Safety distances PY - 2015 SN - 978-0-9867279-8-6 SP - 104 EP - 122 AN - OPUS4-34344 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kurth, Lutz A1 - Krebs, Holger A1 - Theil, Benjamin A1 - Mücke, Olaf T1 - Untersuchungen zur Initiierung von Sekundärsprengstoffen N2 - In den Untersuchungen zum Zündvermögen von Filmeffektzündern wurde nachgewiesen, dass diese einen Plastiksprengstoff auf Basis von PETN nicht zu einer detonativen Umsetzung anregen können. Die Erfüllung der grundlegenden Sicherheitsanforderung (ESR) des Anhanges 1 der Richtlinie 2013/29/EG und die Kategorisierung als pyrotechnischer Gegenstand für Theater (T2) kann somit als gegeben angesehen werden, da der verwendete Explosivstoff zur Gruppe der sensibelsten Sprengstoffe (Initiierung mit geringen Zündenergien) gehört. Es wurde weiterhin nachgewiesen, dass der Untemassertest nach DIN EN 13763 Teil 15 aussagekräftige Ergebnisse liefert, welche die Fähigkeit von Filmeffektzündern und vergleichbaren pyrotechnischen Gegenständen bestätigen respektive widerlegen, einen Sekundärsprengstoff zu zünden (eine Detonation zu initiieren). Für eine allgemeine Einschätzung des Zündvermögens von Filmeffektzündern und vergleichbaren pyrotechnischen Gegenständen ist ein Grenzbereich für ein äquivalentes Zündvermögen in g PETN auf Basis der Experimente mit dem o. g. Unterwassertest bestimmt worden. Filmeffektzünder und vergleichbare pyrotechnische Gegenstände sind nicht in der Lage, einen Sekundärsprengstoff zur Detonation anzuregen, wenn das aus dem Unterwassertest ermittelte äquivalente Zündvermögen unter 0,25 g PETN liegt. T2 - 36. Informationstagung Sprengtechnik CY - Siegen, Germany DA - 25.04.2014 PY - 2015 SN - 0941-4584 VL - 36 IS - 3 SP - 20 EP - 24 PB - Deutscher Sprengverband CY - Siegen AN - OPUS4-32520 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kurth, Lutz A1 - Krebs, Holger A1 - Lohrer, Christian A1 - Theil, Benjamin A1 - Mücke, Olaf T1 - Assessment of explosives in squibs N2 - Experiments in this study reveal that the initiating capability of commonly used squibs is not high enough to initiate PETN in all cases. The fulfilment of the ‘new’ essential safety requirement 4 as set out in the European directive 2013/29/EU and the categorization of squibs as theatrical pyrotechnic articles (T2) can therefore be justified, as the explosive investigated belongs to quite a sensitive type (Initiation with low impulse energies possible). Underwater initiating capability tests according to EN 13763-15 led to meaningful results, showing that squibs are usually unable to initiate a secondary explosive. For a general assessment of the initiating capability of squibs and comparable (theatrical) pyrotechnic articles a threshold range of an equivalent initiation capability in grams of PETN on the basis of the performed underwater initiating capability tests was determined. It was found that squibs are generally not capable of initiating secondary explosives if the underwater initiating capability test showed an equivalent Initiation capability below 0.25 g PETN. As a consequence of this result, the underwater initiating capability test gives an effective and safer alternative to the experimental confirmation of the ‘new’ ESR 4 by direct contact of the article with the secondary explosive and should then be preferred to it. KW - Squibs KW - ESR 4 KW - PETN KW - Underwater initiating capability KW - Pyrotechnic PY - 2013 SN - 1082-3999 IS - 32 SP - 57 EP - 66 PB - Journal of Pyrotechnics Inc. CY - Whitewater, CO 81527 USA AN - OPUS4-48207 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Dümmel, Martin A1 - Lohrer, Christian A1 - Mücke, Olaf T1 - Tumbling effects of cylindrical shells N2 - In the future new types of lift charges for display Shells will enter the market. These types may not be based on black powder and therefore will show different Performance behaviors. The European standard series EN 16261 deals with the testing and assessment of display fireworks in order to satisfy the essential safety requirements which have to be met before placing these items on the EU market. The aim of the study is to investigate how certain types of lift charges (NC based) influence the lift, tumbling and drift of cylindrical shells. In consequence, if the performance characteristics deviate strongly from those of typical black powder, safety related regulations in the EU and Germany might be affected, as well. For these investigations, over 50 cylindrical shells were specifically manufactured at BAM to guarantee full influence on all relevant constructional aspects. The shells were constructed to be “blind”, i. e. without break and effect charges, to investigate drift effect on ground in relation to the shooting location. The only reactive substances were the lift charges and a tracer star at the bottom of the shells to guarantee visibility for the post processing using the video grammetric system. The cylindrical shells were of a nominal caliber of 100 mm and manufactured in three different length configurations (single, double and triple length). Their gross weights were designed to correspond to typical effect shells of the same kind. In addition, the impact of different weight distributions inside the shells, leading to altered balance points, on the performance parameters of the shells were also part of this study. Three different types of NC based lift charges were used to show a variety in pressure build ups. T2 - 16th International Symposium on Fireworks CY - Omagari, Japan DA - 24.04.2017 KW - Fireworks KW - Shells KW - Tumbling PY - 2017 SP - 305 EP - 322 AN - OPUS4-40608 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -