Archive for November 2014

Comparison of national “safety distances” at professionally fired firework displays and distances derived from ShellCalc©

Tom Smith & Christian Lohrer

Abstract: There is a wide variety of approaches across the world in determining appropriate “safety distances” for firework displays. Comparison of the different national approaches and distances for shells derived from ShellCalc© highlights the variety and derivation of the “safety distances” adopted and these distances are related to the various failure modes of shells that may affect the audience. It is not intended that this paper should encourage the maximum distances derived always to be adopted, but that an appreciation of the probabilities and hazards of various accident scenarios and therefore the risks involved be part of the decision making process for designers and commissioners of displays as well as enforcing authorities.


Ref: JPyro, Issue 33, 2014, pp53-63 (J33-53)


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Display Fireworks And Stage Pyrotechnics In Use – Which Distances Are ‘Safe’ In Germany And Other Parts Of the EU?

Christian Lohrer

Abstract: Display fireworks and theatrical pyrotechnic articles are widely used in the EU by persons with specialist knowledge for local festivities, events, concerts and various music shows. According to the European Directive 2013/29/EU relating to the making available on the Union market of pyrotechnic articles, these articles are categorized as fireworks of category F4 and theatrical pyrotechnic articles of category T2, respectively. Before these pyrotechnic articles may be made available on the market, manufacturers must ensure that they satisfy the essential safety requirements (ESR) of this Directive. By application of the standard series EN 16261 for F4 articles and EN 16256 for T2 articles an assumption of conformity to the ESR is triggered. Both standards do not specify minimum safety distances to the spectators or to the audience, but give guidance to the Member States for setting up their own regulations for defining the safety distances by means of measured article-dependent performance parameters or construction properties. These safety distances differ between the Member States due to the cultural differences and various methods of calculation. This paper explains the procedures for defining safety distances for F4 and T2 in Germany. Respective advantages and disadvantages are pointed out, and results for identical items, categorized as F4 and T2, illustrate the current measures www.otcsildenafil.net. In addition, a brief overview of the corresponding regulations regarding display fireworks in some other European Member states is presented. The different approaches are compared with each other by calculating the respective safety distances for identical articles.


Ref: JPyro, Issue 33, 2014, pp39-51 (J33-39)


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JPyro – Issue 33, 2014 – Contents

Papers:

Ref: JPyro, Issue 33, 2014
(J33)

 

 

 

JPyro – Issue 32, 2013 – Contents

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Green Pyrotechnic Formulations Based on Metal-Free and Nitrogen-Rich Tetrazolylborate Salts

Thomas M. Klapötke, Magdalena Rusan and Jörg Stierstorfer

Abstract: The investigation of green-burning boron-based compounds as colorants in pyrotechnic formulations as an alternative for environmentally and health hazardous barium nitrate is reported here. Metal-free and nitrogen-rich dihydrobis(5-aminotetrazolyl)borate salts and dihydrobis(1,3,4-triazolyl)borate salts have been synthesized and characterized by NMR spectroscopy, elemental analysis, mass spectrometry and vibrational spectroscopy. The energetic and thermal properties have been determined as well. Crystal structures of compounds 5b, 7 and 13 were obtained. Pyrotechnic compositions have been prepared using selected dihydrobis(azolyl)borate salts as green colorants. In these compositions ammonium dinitramide and ammonium nitrate haven been used as oxidizers, and boron and magnesium as fuels. The burn time, dominant wavelength, spectral purity, luminous intensity and luminous efficiency as well as the thermal and energetic properties of these compositions were measured.


Ref: JPyro, Issue 33, 2014, pp24-38 (J33-24)


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Quantification of Visible Aerosols from Pyrotechnics: Metal and Metal Compound Additives

Rene Yo Abe, Yoshiaki Akutsu, Akihiro Shimada and Takehiro Matsunaga

Abstract: The effect of metal and metal compounds commonly used in pyrotechnics on visible aerosol development at high relative humidity has been investigated in combustion experiments using a combustion chamber. Ammonium perchlorate/ hydroxyl-terminated polybutadiene as oxidant/fuel system allowed aerosols generated from the additives to be observed in the absence of particles generated from the base composite. For magnesium and magnalium and all flame coloring agents except barium nitrate, light extinction measurements at 80% relative humidity were found to be proportional to the mass concentration of hygroscopic metal compound particles which are formed at high temperatures from metal chloride or metal vapors during combustion. Low visible aerosol development under humid conditions was observed for aluminium and titanium which have higher boiling points than magnesium and do not readily vaporize during combustion, as well as for barium nitrate which forms too small hygroscopic barium chloride particles and iron(iii) oxide which, because of its low boiling point, forms coarser iron(iii) chloride particles at lower temperatures.


Ref: JPyro, Issue 33, 2014, pp16-23 (J33-16)


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