TY - JOUR A1 - Léonard, Fabien A1 - Zhang, Zhen A1 - Krebs, Holger A1 - Bruno, Giovanni T1 - Structural and Morphological Quantitative 3D Characterisation of Ammonium Nitrate Prills by X-ray Computed Tomography N2 - 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. KW - ANFO KW - Explosives KW - Surface area KW - Porosity KW - XCT KW - Data processing PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-505395 DO - https://doi.org/10.3390/ma13051230 VL - 13 IS - 5 (Special Issue "Micro Non-Destructive Testing and Evaluation") SP - 1230 PB - MDPI AN - OPUS4-50539 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Léonard, Fabien A1 - Hasenfelder, Uta A1 - Krebs, Holger A1 - Bruno, Giovanni T1 - Assessment of shock tube systems by synchrotron X-ray computed tomography N2 - 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. KW - Explosives KW - Nonel KW - Shock wave KW - Blasting KW - Energetic systems PY - 2017 UR - http://www.ndt.net/events/iCT2017/app/content/Paper/61_Leonard.pdf SP - 1 EP - 7 CY - Leuven, Belgium AN - OPUS4-39345 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Léonard, Fabien A1 - Zhang, Zhen A1 - Krebs, Holger A1 - Bruno, Giovanni T1 - Morphological characterisation of explosive powders by XCT: When grain numbers count N2 - 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. T2 - 10th Conference on Industrial Computed Tomography (iCT 2020) CY - Wels, Austria DA - 04.02.2020 KW - Ammonium nitrate KW - Prill KW - Non-destructive characterisation KW - Porosity KW - Specific surface area PY - 2020 UR - http://www.ndt.net/?id=25118 SN - 1435-4934 VL - 25 IS - 2 SP - 1 EP - 6 PB - NDT.net CY - Kirchwald AN - OPUS4-50348 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mishra, Kirti Bhushan A1 - Wehrstedt, Klaus-Dieter A1 - Krebs, Holger T1 - Boiling liquid expanding vapour explosion (BLEVE) of peroxy-fuels: Experiments and computational fluid dynamics (CFD) simulation N2 - 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. KW - BLEVE KW - Hydrocarbons KW - Peroxy-fuels KW - Safety distances KW - CFD simulation PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-334184 DO - https://doi.org/10.1016/j.egypro.2015.02.082 SN - 1876-6102 VL - 66 SP - 149 EP - 152 PB - Elsevier Ltd. CY - Amsterdam AN - OPUS4-33418 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Godehardt, M. A1 - Krebs, Holger A1 - Ohser, J. A1 - Staude, Andreas T1 - Analyse der Porengrößenverteilung in einer myCT-Aufnahme eines Sprengstoffes N2 - An der BAMIine von BESSY II wurden durch Mikro-Computertomographie (pCT) 3D-Bilder der Mikrostruktur von drei verschiedenen Explosivstoffen aufgenommen (Probennummern 2075, 2076, 2077), von denen zunächst nur der 3DDatensatz von Probe 2075, eines mit Mikrohohlkugeln sensibilisierten Emulsionssprengstoffes, analysiert wurde. Für die anderen Proben erschien der Aufwand zur Charakterisierung der Mikrostruktur zu hoch bzw. muss die Zielstellung der Analyse noch klarer formuliert werden. PY - 2012 SN - 0941-4584 VL - 34 IS - 1 SP - 3 EP - 4 PB - Deutscher Sprengverband CY - Siegen AN - OPUS4-27976 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -