TY - JOUR A1 - Abdelkhalik, A. A1 - Askar, Enis A1 - Markus, D. A1 - Brandes, E. A1 - El-Sayed, I. A1 - Hassan, M. A1 - Nour, M. A1 - Stolz, T. T1 - Explosion regions of propane, isopropanol, acetone, and methyl acetate/inert gas/air mixtures JF - Journal of Loss Prevention in the Process Industries N2 - The explosion regions for propane, isopropanol, acetone, and methyl acetate with air in the presence of nitrogen, argon, helium, and carbon dioxide were determined experimentally according to EN 14756/EN1839, method T. Except for propane, all the measurements were executed at 323 K and 1 bar. Propane experiments were carried out at 293 K and 1 bar. The results show that for the same type of inert gas, propane, isopropanol, and acetone have great closeness concerning the concentration of the inert gas at the apex of the explosion envelope in a ternary diagram with air as oxidizer. This leads to consistency in the limiting oxygen concentration (LOC) and minimum required amount of inert gas (MAI) values. Concerning methyl acetate, the apex was always reached at higher percentages of inert gases compared with the other fuels. This can be attributed to the presence of two oxygen atoms inside the chemical structure. Calculation of the explosion regions was carried out based on calculated adiabatic flame temperature (CAFT) method. The flame temperatures for the experimentally determined fuel/air/N2 mixtures were calculated. Then, these temperatures were used to predict the explosion limits of similar mixtures with other inert gases than nitrogen. The modeling results show reasonable agreement with the experimental results. KW - Flammability limits KW - Model of constant adiabatic flame temperatures (CAFT) KW - Inertisation KW - Explosion protection PY - 2016 DO - https://doi.org/10.1016/j.jlp.2016.04.001 SN - 0950-4230 VL - 2016/43 SP - 669 EP - 675 PB - Elsevier Ltd. CY - Oxford, UK AN - OPUS4-37996 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Askar, Enis A1 - Schröder, Volkmar A1 - Schmid, T. A1 - Schwarze, M. T1 - Explosion characteristics of mildly flammable refrigerants ignited with high-energy ignition sources in closed systems JF - International Journal of Refrigeration N2 - For evaluation of explosion scenarios in closed systems involving the mildly flammable refrigerants R1234yf, R1234ze and R32 dependent on the ignition energy, ignitions were carried out in a closed autoclave. A newly developed ignition system was used, which allows generating electric arcs with defined energies in a range between 3 J and 1000 J. The lower explosion limit of R32 decreases with increasing ignition energy. R32-explosions can be more severe than explosions involving highly flammable substances. However, in case of R1234yf and R1234ze, the ignition energy had to be increased to more than 100 J and more than 500 J to detect explosions in the closed system at all, although flame Propagation phenomena can already be observed if these substances are ignited with much weaker ignition sources in open glass tubes. The explosions were very mild with these substances. KW - Flammability limits KW - Explosion severity KW - R1234yf KW - R1234ze KW - R32 KW - Hydrofluoroolefin (HFO) PY - 2018 DO - https://doi.org/10.1016/j.ijrefrig.2018.04.009 SN - 0140-7007 SN - 1879-2081 VL - 90 SP - 249 EP - 256 PB - Elsevier Ltd and IIR AN - OPUS4-45879 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Molnarne, M. A1 - Seifert, Alexander A1 - Schröder, Volkmar T1 - Explosion protection according to the EU directives using the data from CHEMSAFE database JF - Procedia engineering N2 - For international trade and production of machinery used in potentially explosive atmospheres it is important to know about the regulations within the European Union. This paper presents an application of CHEMSAFE flammability data for fulfilling the requirements of the EU explosion protection directives. Most of the published data for flammability of substances are measured under atmospheric conditions although chemical processes operate often under non-atmospheric conditions. A couple of R&D projects were initiated in Germany to get more knowledge on explosion characteristics for non-atmospheric conditions. The explosion protection for machinery operated under non-atmospheric conditions is defined in the 2006/42/EU Directive. CHEMSAFE fulfills this requirement while it contains data of flammable compounds measured under non-atmospheric conditions and with other oxidizers than air. Furthermore it includes flammability data for gas mixtures consisting of flammable, inert, and different oxidizing components and most of the data are measured according to international standards. Safety data on flammable dusts - such as minimum ignition energy, maximum explosion pressure, ignition temperatures - represents also an important part of the database. The potentially explosive atmospheres are defined in revised Directive 2014/34/EU. For preparing risk assessment documents the following data for flammable gases and vapors, relating to the use of equipment, among others are necessary: Flammability limit, flash point, temperature class - auto-ignition temperature, maximum experimental safe gap. CHEMSAFE'2013 includes not only these data but also more than 200 triangular explosion diagrams, e.g. the newly measured methane/nitrogen/oxygen system under pressures up to 50 bars. The international standard Draft of IEC 80079-1-1 publishes data tables for flammable substances originated from CHEMSAFE which represents the international acceptance of these data. KW - Flammability limits KW - Gas and dust explosion KW - Explosion protection KW - Safety characteristics KW - Technical regulations KW - Safety data KW - CHEMSAFE database PY - 2014 DO - https://doi.org/10.1016/j.proeng.2014.10.432 SN - 1877-7058 VL - 84 SP - 247 EP - 258 PB - Elsevier CY - Amsterdam [u.a.] AN - OPUS4-32086 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -