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Industrial fire and explosion hazards due to accidents in fuel storage units have gained a
considerable attention in the recent times. Both the regulatory bodies and scientific communities
are heavily concerned about the proper safety measures to avoid such calamities in future. This
paper aims to bring some essentials related to the hazards arose from the recent fuel storage fire
accident occurred in Buncefield, UK (2005), Puerto Rico, USA (2009) and Sitapura, India (2009).
The potential similarities behind occurrence of these accidents are studied. The applicability of
various methods (models) and also computer simulations to estimate the safety distances
according to the international standards for both explosion and fire hazard are verified. The
overpressures caused by the Vapor Cloud Explosion (VCE) and radiation flux emitted by the fire
are considered for respective explosion and fire hazard estimations. The prime focus is placed
on the regulations laid down by the National Fire Protection Agency of the United States and
the European Norms.
Industrial fire and explosion hazards due to accidents in fuel storage units have gained a considerable attention in recent years. Both, the regulatory bodies and scientific communities are heavily concerned about the proper safety measures to avoid such calamities in the future. This paper aims to bring some essentials related to the hazards that arose from recent fuel storage fire accidents occurring in Buncefield, UK (2005), Puerto Rico, USA (2009) and Sitapura, India (2009). The potential similarities behind occurrence of these accidents are studied. The applicability of various methods (models) and also computer simulations to estimate the safety distances according to the international standards for both explosion and fire hazard are verified. The overpressures caused by the Vapor Cloud Explosions (VCE) and radiation fluxes emitted by the fires are considered for respective explosion and fire hazard estimations. The prime focus is placed on the regulations laid down by the National Fire Protection Agency of the United States and the European Norms.
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.
Zwei Verfahren, der Unterwasser-Test und der Plate-Dent-Test, wurden hinsichtlich ihrer Eignung zur indirekten Bestimmung
der Zündstärke von Zündern untersucht. Die Einflüsse verschiedener Sekundärladungsmassen und unterschiedlichen
Hülsenmaterials von Zündern standen hierbei im Vordergrund.
Der Unterwasser-Test, bei dem als Maß für die Zündstärke die Stoß- und Blasenenergie eines Zünders ermittelt werden,
erwies sich als probate und genaue Bestimmungsmethode. Zünder mit unterschiedlichen Sekundärladungsmassen waren
eindeutig differenzierbar. Das Hülsenmaterial hatte nur einen vernachlässigbaren Einfluss auf die Ergebnisse.
Der Plate-Dent-Test, bei dem die Abmaße des gebildeten Kraters zur indirekten Bestimmung der Zündstärke herangezogen
werden, zeigte gegenteilige Effekte. Ab einem Ladungslänge-Durchmesser-Verhältnis von größer zwei war eine Differenzierung
von Zündern verschiedener Sekundärladungsmasse nicht mehr möglich. Außerdem hatte das Hülsenmaterial
einen signifikanten Einfluss auf die Kraterbildung. Der Plate-Dent-Test ist somit nur für den direkten Vergleich der Zündstärken
baugleicher Zünder z. B. unter variierenden Umweltbedingungen geeignet.---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Two procedures – the underwater test and the plate-dent-test – were examined concerning their applicability for the indirect
determination of the initiating capability of detonators. At this the focus was on the influence of varying explosive masses
and different shell material.
At the underwater test the initiating capability is determined indirectly by measurement and calculation of the shock and
bubble energy. This method proved to be effective and accurate. Detonators with different secondary charge masses could
be distinguished clearly and the shell material had only a negligible influence on the energy release.
The plate-dent-test, at which the dimensions of the formed dent are an indirect measure for the initiating capability, showed
the contrary effects. A differentiation of detonators was proved to be impossible when a relation of charge length to diameter
greater than two was reached. Furthermore, it could be shown that the shell material had significant influence on the
dent formation. Therefore, the plate-dent-test is only suitable for the direct comparison of identical detonators, e. g. under
varying environmental conditions.
Amuay refinery disaster (2012) is another recent example of Vapor Cloud Explosion (VCE) and fire accidents preceded by Buncefield (2005), Puerto-Rico (2009) and Jaipur (2009), respectively [9]. The incident has left many safety issues behind which must be repeatedly addressed. Unfortunately, the lessons taught by previous similar events are just not understood carefully. It reveals that the proper safety measures for such facilities were either underestimated or were not accounted seriously. Consequently, the resulting overpressures from explosion and the subsequent thermal radiation from tank fires have once again proved to be disastrous to both mankind and infrastructure. This article highlights the aftermaths of Amuay incident and addresses the challenges put forward by it. Furthermore, a comparative study is performed between such incidents to analyze the similarities and how they could have been avoided.
Pyrotechnische Gegenstände für technische Zwecke - Zerkleinern von Fundamenten und Steinblöcken -
(2014)
Die quantitative Bestimmung toxischer Gase, die bei der Umsetzung von Sprengstoffen entstehen können, ist für alle unter Tage verwendeten Sprengstoffe vorgeschrieben.
In der europaweit harmonisierten Norm DIN EN 13631 Teil 16 wird die Prüfmethode spezifiziert. Die wichtigsten Vorgaben und Anforderungen der Norm und deren Realisierung in der BAM - Prüfmethode werden erläutert. Der Aufbau und die Funktionsweise der BAM – Schwadenkammer, die eingesetzte Beprobungs- und Messtechnik und die Datenauswertung werden beschrieben.
Für die jeweiligen Sprengtypen (ANFO, Emulsionen, gelatinöse Sprengstoffe) werden die gemittelten Gaskonzentrationen für Stickoxide und Kohlenmonoxid diskutiert, die aus den bisher durchgeführten Prüfungen an der BAM resultieren.
Die nunmehr seit mehr als 10 Jahren an der BAM durchgeführten Schwadenprüfungen von gewerblichen Sprengstoffen zeigen, dass die Prüfmethode verlässliche und gut reproduzierbare Ergebnisse liefert. Konstante Prüf- und Umgebungsbedingungen ermöglichen die Vergleichbarkeit der Schwaden-Konzentrationen verschiedener Sprengstoffe.
Der Vergleich mit Werten anderer Prüfeinrichtungen ist jedoch nur eingeschränkt möglich. Insbesondere die Einschlussbedingungen haben einen großen Einfluss auf die Schwadenzusammensetzung. Dies zeigte sich an den alten Prüfergebissen, die noch in der Bergbauversuchstrecke „Tremonia“ oder im späteren Sprengbunker der DMT ermittelt wurden, sowie beim Vergleich mit Messwerten unter Bergbaubedingungen. Zu einem ähnlichen Fazit kam auch ein Ringversuch zwischen den Benannten Stellen, der im Jahr 2009 durchgeführt wurde. Die Messergebnisse der Schwadenprüfung in verschiedenen Versuchseinrichtungen werden vorgestellt und Übereinstimmungen sowie Abweichungen diskutiert.
Fire and explosion hazards associated with storage and transportation of flammable materials have been a matter of great interest in the recent times. BLEVE is a scenario that occurs when a closed fuel container is subjected to heat for a longer duration. Such events are disastrous to human beings and assets both. In the past there have been numerous studies on BLEVEs and fireballs of hydrocarbon fuels, e.g. kerosene, gasoline, LPG, LNG and others. Though, the fireballs of peroxy-fuels are not looked into detail as such. This article tries to overcome this lack of knowledge. Both, experimental investigation and CFD simulations are performed to measure and predict the fireball characteristics of a peroxy-fuel. Due to thermal decomposition in the liquid phase and active oxygen content a peroxy-fuel fireball burns at a very fast rate and emit higher thermal radiation whereas exhibits smaller diameter and elevation compared to hydrocarbons. That eventually leads to consideration of larger safety distances from them which are also verified by CFD results.
More than 5 million non-electric detonators are used annually in Germany for blasting operations. The relative usage of non-electric detonators amounts to about 50% of all civil blasting operations in Germany. BAM, as the notified body for explosives in Germany, tests non-electric detonators for the purpose of EU-type approval under the civil explosives directive, but also in the context of general investigations, e.g. when misfiring occurs. BAM has all facilities to test these detonators according to the European standard EN 13763. The presentation will cover the test facilities of BAM and address some issues of delay time accuracy. Several advantages and disadvantages of the non-electric ignition system will be discussed in the context of case investigations, and conclusions for mining operations and the advoidance of misfiring will be drawn.
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.
Pyrotechnische Gegenstände in Form von Treibladungskartuschen für den Einsatz in der Sprengtechnik
(2015)
Anforderungen, Prüfverfahren und praktische Erprobung von Treibladungskartuschen für den Einsatz in der Sprengtechnik werden erläutert. Nach der europäischen Rechtslage und den europäischen Normen handelt es sich bei derartigen Gegenständen um so genannte steinbrechende Kartuschen, die der EU-Richtlinie 2007/23/EG unterliegen und somit als pyrotechnische Gegenstände behandelt werden.
In der Abteilung „Chemische Sicherheitstechnik" der BAM wurden mittels Ultra-Hochgeschwindigkeitsvideotechnik Grundlagenuntersuchungen zu Detonationsverhalten und Splitterwirkung von sogenannte "schlagwettersichern” Sprengzündern in normaler und in explosionsfähiger Atmosphäre durchgeführt. Es konnte eine maximale Splittergeschwindigkeit von 2,4 km/s ermittelt werden.
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.
Neben den EG-Baumusterprüfungen und Konformitätsbewertungen, die von der BAM als Benannte Stelle nach den Richtlinien 2014/28/EU und 2013/29/EU durchgeführt werden, gibt es auch immer wieder Anfragen von Behörden, Herstellern oder Anwendern zur gesonderten Überprüfung von Zündern. Diese Anfragen liegen hauptsächlich in den Bereichen Identifizierung von Fundzündern, Untersuchungen an Versagerzündern/überlagerten Zündern sowie externe Qualitätssicherung von Firmen. Die Vorgehensweise und die Prüfmethoden, die bei solchen Untersuchungen zum Einsatz kommen, werden vorgestellt und an Beispielen erläutert.
Autoclave methods are commonly used when pressure progress under thermal stress is of interest. One of them is the mini-autoclave method by Kühner AG. To test the robustness of the equipment under powerful exposure, two known high energetic materials, DNT and TNT, were investigated. The sample mass was increased stepwise in the range from 0.25 g to 1.0 g. For one test (1 g TNT), gas burners instead of the usually employed 2-zone heating block, were used to intensify the test conditions. Results showed the expected slower pressure generation of DNT in comparison to TNT. The mechanical robustness of the apparatus could be approved in all runs. Pressure data were used to calculate the energy release of decomposition. The values were in good agreement with the heat of decomposition, estimated by DSC.
The mixture of ammonium nitrate (AN) prills and fuel oil (FO), usually referred to as ANFO, is extensively used in the mining industry as a bulk explosive. One of the major performance predictors of ANFO mixtures is the fuel oil retention, which is itself governed by the complex pore structure of the AN prills. In this study, we present how X-ray computed tomography (XCT), and the associated advanced data processing workflow, can be used to fully characterise the structure and morphology of AN prills. We show that structural parameters such as volume fraction of the different phases and morphological parameters such as specific surface area and shape factor can be reliably extracted from the XCT data, and that there is a good agreement with the measured oil retention values. Importantly, oil retention measurements (qualifying the efficiency of ANFO as explosives) correlate well with the specific surface area determined by XCT. XCT can therefore be employed non-destructively; it can accurately evaluate and characterise porosity in ammonium nitrate prills, and even predict their efficiency.
Ammonium nitrate (AN) prills are commonly used as an ingredient in industrial explosives and in fertilisers. Conventional techniques (such as BET or mercury intrusion porosimetry) can measure the open porosity and specific surface area of AN prill, but the closed porosity is not obtainable. This work was focused on evaluating X-ray computed tomography (XCT) as a non-destructive technique for the assessment of porosity in AN prills. An advanced data processing workflow was developed so that the segmentation and quantification of the CT data could be performed on the entire 3D volume, yet allowing the measurements (e.g.; volume, area, shape factor…) to be extracted for each individual phase (prill, open porosity, closed porosity) of each individual prill, in order to obtain statistically relevant data. Clear morphological and structural differences were seen and quantified between fertiliser and explosive products. Overall, CT can provide a very wide range of parameters that are not accessible to other techniques, destructive or non-destructive, and thus offers new insights and complementary information.
The explosion and fire incidents with buried gas pipelines are increasing globally e.g. San Bruno (USA, 2010), East Godavari (India, 2014) and Ludwigshafen (Germany, 2014) are only a few to quote. There are a number of parameters involved behind the occurrence of these incidents such as human mistake, intended efforts leading to major or minor leak, explosion due to depressurization, crater formation, spill of gaseous fuel in the nearby regions and pool/jet/crater fires. In continuation to [3] these parameters are investigated for Ludwigshafen incident in the present work. The semi-empirical and advanced CFD (Computational Fluid Dynamics) based models are utilized to assess the damages caused by the explosion overpressures. Recommendations are also provided on minimum safety distance to be considered for such pipelines to avoid/foresee/mitigate similar hazards in future.
The explosion and fire incidents with buried gas pipelines are increasing globally e.g. San Bruno (USA, 2010), East Godavari (India, 2014) and Ludwigshafen (Germany, 2014) are only a few to quote. There are a number of parameters involved behind the occurrence of these incidents such as human mistake, intended efforts leading to major or minor leak, ex-plosion due to depressurization, crater formation, spill of gaseous fuel in the nearby regions and pool/jet/crater fires. In continuation to [3] these parameters are investigated for Ludwigs-hafen incident in the present work. The semi-empirical and advanced CFD (Computational Fluid Dynamics) based models are utilized to assess the damages caused by the explosion overpressures. Recommendations are also provided on minimum safety distance to be consid-ered for such pipelines to avoid/foresee/mitigate similar hazards in future.
Shock tube systems are non-electric explosive fuses employed in blasting and demolition applications to trigger the detonation of explosive charges. Their working principle is based on the explosive reaction of a fine explosive powder on the tubing's inner surface, generating a shock wave traveling at a velocity of 2,100 m/s along the length of the tube, without destroying it. One of
the key aspects of the manufacturing process of these shock tubes is the size and morphology of the explosive powder grains and their distribution on the inner wall of the tube, in order to propagate the shockwave efficiently and reliably. For the first time, synchrotron X-ray computed tomography has been used to characterize non-destructively the explosive powder grains, typically Al/HMX between 10 and 20 μm in size, in terms of morphology and 3D distribution but also to characterise the presence and location of defects
within the shock tube walls.