TY - CONF A1 - Poli, Marco A1 - Grätz, Rainer A1 - Schröder, Volkmar T1 - Limited applicability of gas explosion venting due to turbulence generation N2 - For the design of gas explosion venting systems for confinements only little guidance is given when considering the constructional boundary conditions or process conditions. For this reason conservative assumptions are prevalent in practice and in many cases the protective Systems become significantly oversized. Such safety margins in venting areas can lead to a critical acceleration of the pressure rise. Finally, a gas explosion at turbulent conditions caused by oversizing of the venting area rather leads to an under-sized system and supports the deflagration to detonation transition (DDT). The present investigation was focused especially on the influence of certain obstacles as well as the effect of the initial pressures on the explosion venting behavior of methane-air-mixtures and of hydrogen-air-mixtures. T2 - 2011 AIChE Spring meeting & 7th global congress on process safety CY - Chicago, IL, USA DA - 12.03.2011 KW - Gas explosion venting KW - Turbulent combustion KW - KG-value PY - 2011 IS - Topical 1 / #13 / 13h SP - 1 EP - 13 CY - New York, NY, USA AN - OPUS4-23376 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Poli, Marco A1 - Grätz, Rainer A1 - Schröder, Volkmar ED - Pierucci, S. ED - Klemes, J.J. ED - De Rademaeker, E. ED - Fabiano, B. ED - Buratti, S.S. T1 - Limitations of gas explosion venting due to accelerated flame propagation and elevated initial pressure N2 - Many industrial processes include a gas explosion hazard. If safety measures are not adequate to prevent a potentially explosive atmosphere or to avoid effective ignition sources in enclosures, at least the effects of an explosion can be limited e.g. by gas explosion venting systems. For the design of gas explosion venting systems for confinements only little guidance is given when considering the constructional boundary conditions or process conditions. For this reason conservative assumptions are prevalent in practice and in many cases the protective systems become significantly oversized. From safety perspective such safety margins in venting areas can lead to a critical acceleration of the pressure rise. Moreover, a gas explosion venting at turbulent conditions caused by over sizing or by obstacles rather leads to an under-sized system. The present investigation was focused especially on the influence of certain obstacles as well as the influence of elevated initial pressures on explosion venting behaviour of quiescent hydrogen, methane or ethylene in air. T2 - 14th International symposium on loss prevention and safety promotion in the process industries CY - Florence, Italy DA - 12.05.2013 KW - Gas explosion venting KW - Turbulent combustion KW - Obstacles PY - 2013 SN - 978-88-95608-22-8 DO - https://doi.org/10.3303/CET1331111 SN - 1974-9791 N1 - Serientitel: Chemical engineering transactions – Series title: Chemical engineering transactions VL - 31 SP - 661 EP - 666 PB - AIDIC, Associazione Italiana di Ingegneria Chimica CY - Milano AN - OPUS4-28582 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Poli, Marco A1 - Grätz, Rainer A1 - Schröder, Volkmar T1 - Hazards of accelerated gas explosion venting and their safety-relevant parameters N2 - The effects of a gas explosion in enclosures like vessels can be limited e.g. by gas explosion venting systems. The major design step of this constructive explosion protection method is to determine the required vent area, which depends significantly on whether turbulent combustion exists. However, current standards like NFPA 68 or EN 14994 are applicable only to limited boundary conditions and as far as possible only to laminar flame propagation. Difficulties arise in the assessment or predictability of gas explosion hazard when turbulence occurs. In this research especially venting at elevated initial pressure has been shown to accelerated flame propagations and therefore, to a considerably higher reduced pressure. Therefore, it is essential to provide a broader data base of turbulent combustion and explosion behaviour to verify the existing rules or to determine their safety-relevant parameters. For a better safety assessment or design of protective systems the turbulent combustion and accelerated gas explosion behaviour of quiescent methane in air were investigated at initial pressures up to 8 bar using vessels up to 100 litres. In particular a systematic study was performed to investigate the influence of turbulence on the overpressure development during accelerated gas explosion. Moreover, the present study consider the position of the spark igniters, the burning velocity and the maximum pressure rise for different concentration of fuel as well as the size of orifice and/or vent area. A choice of experimental tests showed under the investigated conditions that not only turbulence inducing obstacles but also over sized vent areas could lead to an increased pressure development and therefore to an inacceptable safety state. Due to the numerous influencing variables of explosion behaviour the presented experimental results help to judge whether another more sophisticated method should be applied than the one described in standards. T2 - Hazards XXIII Symposium CY - Southport, UK DA - 12.11.2012 KW - Turbulent combustion KW - Obstacles KW - Explosion acceleration PY - 2012 SN - 978-0-85295-557-4 N1 - Serientitel: Symposium Series – Series title: Symposium Series VL - 158 IS - Paper 45 SP - 347 EP - 353 AN - OPUS4-27222 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Poli, Marco A1 - Grätz, Rainer A1 - Schröder, Volkmar T1 - An experimental study on safety-relevant parameters of turbulent gas explosion venting at elevated initial pressure N2 - The effects of a gas explosion in enclosures like vessels can be limited e.g. by gas explosion venting systems. The major design step of this constructive explosion protection method is to determine the required vent area, which depends significantly on whether turbulent combustion exists. However, current standards like NFPA 68 or EN 14994 are applicable only to limited boundary conditions and as far as possible only to laminar flame propagation. Difficulties arise in the assessment or predictability of gas explosion hazard when turbulence occurs. In this research especially venting at elevated initial pressure has been shown to accelerated flame propagations and therefore, to a considerably higher reduced pressure. Therefore, it is essential to provide a broader data base of turbulent combustion and explosion behavior to verify the existing rules or to determine their safety-relevant parameters. For a better safety assessment or design of protective systems the turbulent combustion and accelerated gas explosion behaviour of quiescent methane and hydrogen in air were investigated at initial pressures up to 8 bar using vessels up to 100 litres. In particular a systematic study was performed to investigate the influence of turbulence on the overpressure development during accelerated gas explosion. Moreover, the present study consider the position of the spark igniters, the burning velocity and the maximum pressure rise for different concentration of fuel as well as the size of orifice and/or vent area. A choice of experimental tests showed under the investigated conditions that not only turbulence inducing obstacles but also over sized vent areas could lead to an increased pressure development and therefore to an inacceptable safety state. T2 - 20th International Congress of Chemical and Process Engineering CHISA 2012 CY - Prague, Czech Republic DA - 25.08.2012 KW - Gas explosion venting KW - Turbulent combustion KW - Obstacles PY - 2012 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-264288 DO - https://doi.org/10.1016/j.proeng.2012.07.398 SN - 1877-7058 VL - 42 SP - 90 EP - 99 PB - Elsevier CY - Amsterdam AN - OPUS4-26428 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -