TY - JOUR A1 - Askar, Enis A1 - Schröder, Volkmar A1 - Acikalin, Hatice Aydan A1 - Steinbach, J. T1 - Berechnung von Explosionsgrenzen ethylenoxidhaltiger Gasphasen in Sterilisatoren / Calculation of flammability limits of gas phases with ethylene oxide in sterilisers JF - Biomedizinische Technik = Biomedical engineering N2 - Es wurde ein Verfahren zur Berechnung von Explosionsgrenzen ethylenoxidhaltiger Gasphasen in Sterilisatoren entwickelt. Mit Hilfe der Software GasEq® und des neu entwickelten Makros „SterEx“ für MS-Excel® lassen sich die Explosionsgrenzen für Gemische aus Ethylenoxid, Luft und Inertgasen bei Temperaturen zwischen 20°C und 100°C sowie 0,4 bar und 1,0 bar berechnen. Somit ist es schnell möglich, sichere Betriebsbedingungen für Sterilisationsprozesse mit Ethylenoxid festzulegen. Das halbempirische Modell basiert auf der Annahme konstanter Flammentemperaturprofile an den Explosionsgrenzen in Abhängigkeit der EO-Konzentration für verschiedene Gemische. Durch systematische Zündversuche wurden Explosionsgrenzen für Gemische aus Ethylenoxid, Stickstoff, Kohlenstoffdioxid, Wasserdampf und Luft zur Bestimmung von Modellparametern und zur Validierung des Verfahrens bestimmt. Um die Prozessbedingungen in Sterilisatoren möglichst genau zu simulieren, wurden die Versuche in einem geschlossenen Autoklav in Anlehnung an DIN EN 1839-B durchgeführt. Berechnungen der Explosionsgrenzen von Prozessgasgemischen mit „SterEx“ ergeben eine gute Übereinstimmung mit experimentell ermittelten Werten. ---------------------------------------------------------------------------------------------------------------------------------- A calculation method for flammability limits of gas phases with ethylene oxide in sterilisers was developed. Using the Software GasEq® and the newly developed Makro “SterEx” for MS-Excel®, flammability limits of mixtures with ethylene oxide, air and inert gases at temperatures between 20°C and 100°C and pressures between 0.4 bar and 1.0 bar can be calculated. This method can be used to easily determine safe operating conditions. The used semi-empirical model is based upon the assumption of constant flame temperature profiles at the flammability limits subject to the EO-concentration for different mixtures. To collect model parameters and to validate the model, several experiments with mixtures of ethylene oxide, nitrogen, carbon dioxide, water vapour and air were carried out to determine flammability limits. To simulate the structural conditions of sterilisers, the experiments were conducted in accordance to DIN EN 1839-B in a closed autoclave with temperatures and pressures relevant for sterilisation processes. The calculation of flammability limits of process gas mixtures with “SterEx” provides good agreement with flammability limits that were determined in experiments. KW - Dry antiseptic KW - Ethylene oxide KW - Explosions KW - Inertisation KW - Safety engineering KW - Sterilisation PY - 2008 DO - https://doi.org/10.1515/BMT.2008.042 SN - 0013-5585 SN - 1862-278X VL - 53 IS - 6 SP - 265 EP - 269 PB - De Gruyter CY - Berlin AN - OPUS4-18688 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Binder, Christian A1 - Kasch, Thomas A1 - Brock, Thomas A1 - Beck, Uwe A1 - Weise, Matthias A1 - Sahre, Mario T1 - Promoted combustion testing of pure and ceramic-coated metals in high pressure oxygen by the federal institute of materials research and testing (BAM) JF - Journal of ASTM International N2 - The new promoted ignition combustion test apparatus at BAM matches the requirements of ASTM test method G 124 [ASTM G 124, Standard Test Method for Determining the Combustion Behavior of Metallic Materials in Oxygen-Enriched Atmospheres, 2003] and of EIGA publication, IGC Doc 13/02/E [EIGA Gas Association Document IGC Doc 13/02/E, Oxygen Pipeline Systems, 2003]. The test apparatus is most likely the only one in Europe. The test chamber allows investigations with pure oxygen or oxygen mixtures at pressures up to 500 bar and at temperatures up to 400°C at static or flowing gas conditions. The ignition device consists of an electrical ignition wire and a promoter. IR-sensors, distributed over the whole length of the rod, measure and record the burning temperature and allow measurement of the burn rate. A video system records the experiment for visual characterization of the burning behavior. BAM test results are compared with published data. Results on investigations with coated rods are presented. Ceramic coatings seem to be a solution for the use of certain less compatible metallic materials at higher oxygen pressures. KW - Promoted combustion KW - High pressure oxygen KW - Metallic materials KW - Flammability KW - Safety engineering KW - Coatings PY - 2006 DO - https://doi.org/10.1520/JAI13533 SN - 1546-962X VL - 3 IS - 4 SP - JAI13533, 1 EP - 6 PB - American Society for Testing and Materials CY - West Conshohocken, Pa. AN - OPUS4-12676 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -