TY - CONF A1 - Krietsch, Arne A1 - Gothe, C. A1 - Scheid, Marc A1 - Krause, U. ED - Makhviladze, G. ED - Molkov, V. ED - Bradley, D. ED - Sunderland, P. ED - Tamanini, F. T1 - Determination of explosion behaviour of nano powders with modified 20-L-sphere test T2 - ISFEH7 - 7th International seminar on fire & explosion hazards (Proceedings) N2 - This paper describes a modified experimental setup for the test apparatus 20-L-Sphere (also known as 20-L Siwek Chamber), that enables the test samples to be kept under inert atmospheric conditions nearly until ignition. This setup was designed to allow the determination of safety characteristics of nano powders under most critical circumstances (e.g. minimisation of the influence of oxidation before the test itself). The aim of this modification was to determine, whether or not the current setup and procedures underestimate the explosion violence and ignitability of nano powders. For this purpose, two different methods, the so called inerting method and the modified method (using a special nozzle called mushroom nozzle) are used. Both methods are described in the paper. The work includes experimental results of micrometer dusts to validate the modified method. Moreover first results of nanometer iron and aluminium dusts are presented, which were kept at inert conditions until shortly before the ignition. The tested nano iron was found to react pyrophoric, as soon as it gets in contact with air, while the tested nano aluminium did not generally show such behaviour. Tests with nano aluminium using the inerting method revealed a higher pressure rise in comparison to the standard test procedure. This could suggest a different extent of passivation. To investigate this effect more closely, further testes with more nano powders are required. T2 - ISFEH7 - 7th International seminar on fire & explosion hazards CY - Providence, RI, USA DA - 05.05.2013 KW - Nano material KW - Dust explosion KW - Safety characteristics KW - Nanopowder PY - 2013 SN - 978-981-07-5936-0 SN - 978-981-07-5940-7 DO - https://doi.org/10.3850/978-981-07-5936-0_13-03 SP - 801 EP - 809 PB - Research publishing AN - OPUS4-28560 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -