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Fine chemicals and products of the pharmaceutical industry are produced predominantly in multi-purpose plants. Characteristically, they comprise of many recipes and very different processes. The challenge is often to adapt a certain process to a given plant. At first the sizing scenarios must be identified by means of a systematic risk analysis. Secondly, the process operation must be bounded to fulfill the requirements of the existing protection concept of the plant. This includes proper limits of the process control interlocks and the proper operation of safety devices and following disposal systems. A general concept is presented for the safe operation of multi-purpose plants. Starting with the identification of hazardous potentials an evaluation by means of critically classes is demonstrated. A sizing procedure is given for recalculating an existing safety device according to ISO 4126 part 10. It is based on a concept of energy specific valve seat areas. About 60 typical solvents are applied to the concept. © 2011 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.


Fath W.,BASF | Blum C.,DEKRA EXAM GmbH | Glor M.,Swissi Process Safety GmbH | Walther C.-D.,Bayer AG
Journal of Electrostatics | Year: 2013

During transportation of powder through pipes or hoses made from insulating materials, electrostatic discharges can occur. To define the resistivity limit of the insulating material for the avoidance of propagating brush discharges, the charging current due to the powder transfer was determined experimentally using different types of hoses and bulk material. The subsequent modeling shows that propagating brush discharges will not occur if such hoses are constructed from dissipative materials or when the resistance measured from the inner surface to the conductive structure of the hose multiplied with the contact area of the electrode is below 4 MΩ m2. © 2012 Elsevier B.V.


Glor M.,Swissi Process Safety GmbH | Blum C.,DEKRA EXAM GmbH | Fath W.,BASF | Walther C.-D.,Bayer AG
Process Safety and Environmental Protection | Year: 2014

When transferring powder through pipes or hoses made from insulating material, propagating brush discharges cannot be excluded. To calculate the limit value of the resistivity of the insulating material, below which no propagating brush discharges will occur, the charging current due to the powder transfer must be known. This charging current has been determined experimentally. Based on analytical calculations and computer models limit values for the resistivity of the hose material are derived from these experiments. © 2014 The Institution of Chemical Engineers.


De Rademaeker E.,Prevention Management International BVBA | Suter G.,Swissi Process Safety Gmbh | Pasman H.J.,Texas A&M University | Fabiano B.,University of Genoa
Process Safety and Environmental Protection | Year: 2014

In 2013, the European Federation of Chemical Engineering (EFCE) celebrates its 60th anniversary. EFCE has continually promoted scientific collaboration and supported the work of engineers and scientists in thirty European countries. As for its mission statement, EFCE helps European Society to meet its needs through highlighting the role of Chemical Engineering in delivering sustainable processes and products. Within this organizational framework the Loss Prevention Symposium series, organized throughout Europe on behalf of the Loss Prevention Working Party of the EFCE, represents a fruitful tradition covering a time span of forty years. The tri-annual symposium gathers experts and scientists to seek technical improvements and scientific support for a growingly safer industry and quality of life. Following the loss prevention history in this paper, a time perspective on loss prevention and its future is presented. © 2014 The Institution of Chemical Engineers.


Glor M.,Swissi Process Safety GmbH | Moritz K.,Merck KGaA
Chemical Engineering Transactions | Year: 2016

It is a well-known fact that the relative humidity of air may have an influence on the build-up of static electricity on equipment, installations, packages, personnel, etc. However the questions arise whether in industrial practice the increase of the relative humidity of air is sufficiently effective to prevent ignition of explosive atmospheres by static electricity, whether at high relative humidity earthing is no longer required and what are the limit values. In the present paper comprehensive measurements and results are presented, which clearly show that even an increase of the relative humidity of air above approximately 70% does not reduce the buildup of static electricity to such a degree that the well-known measures like earthing, use of conductive or dissipative materials, etc. are no longer required. © Copyright 2016, AIDIC Servizi S.r.l.


Glor M.,Swissi Process Safety GmbH | Pey A.,Swissi Espana SLU
Journal of Electrostatics | Year: 2013

Computer modelling and simulation of electrostatic phenomena is nowadays not very often used in industry for an assessment of ignition hazards due to static electricity. With 4 examples (silo filling and assessment of occurrence of cone discharges, calculation of capacitances of screws and flanges for assessment of earthing and bonding requirements, influence of sample geometry on the surface resistance and surface resistivity and assessment of requirements for plastic hoses with a metal spiral for pneumatic transfer of powders) the usefulness and benefit of model calculations of electrostatic phenomena for the assessment of electrostatic ignition hazards is demonstrated. © 2012 Elsevier B.V.


Abele S.,Actelion Pharmaceuticals | Schwaninger M.,Swissi Process Safety GmbH | Fierz H.,Swissi Process Safety GmbH | Schmidt G.,Actelion Pharmaceuticals | And 2 more authors.
Organic Process Research and Development | Year: 2012

The Diels-Alder reactions of the diene (cyclohexa-1,5-dien-1-yloxy) trimethylsilane with either of the two dienophiles α-acetoxyacrylonitrile or α-chloroacrylonitrile pose severe safety hazards for scale-up. We report the systematic thermal hazard assessment of these Diels-Alder reactions and discuss their classification according to the Stoessel criticality diagram. Whereas the use of α-acetoxyacrylonitrile is not recommended, the reaction of the diene with α-chloroacrylonitrile can be scaled up when running the reaction in toluene in the presence of 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) and sodium bicarbonate. © 2012 American Chemical Society.


Forestier S.,Swissi Process Safety GmbH
Chemical Engineering Transactions | Year: 2016

In the European Union, assessing the hazard of the explosion in a plant of a dust or gas atmosphere is mandatory for its manager (European directive 1999/92/EC). This assessment relies on three different steps:-the identification of the position of explosive areas and their frequency (appear during normal process, appear rarely during normal process, do not appear during normal process, do not appear at all) based on the standards IEC 60079-10-1 for gas atmospheres and IEC 60079-10-2 for dust atmospheres-the identification and the assessment of the frequency occurrence of ignition sources based on the standard EN 1127-1-the assessment of the plausible consequences of an explosion based on the standard ISO 14121-1. When the assessment highlights that the hazard of explosion is too high, some corrective measures must be implemented to decrease this hazard to a reasonably value. It is common that for a large plant, several dozens of actions need to be implemented. To the authors' knowledge, there is a lack of method in the literature to help HSE engineers to rank the actions to be taken. What should be corrected first? A very rare deviation that could severely injure or even kill an operator or a less dangerous but more frequent one? This paper proposes a method derived from the determination of a SIL level (standard IEC 61511-3). A similar decision tree is build which is based on the consequences of the explosion defined in ISO 14121-1. It takes into account the probability of attendance of an operator in the hazardous area and the frequency of occurrence of an ignition source and of an explosive atmosphere. This method gives an index for each couple of [consequence of an explosion/ frequency of occurrence of an explosion]. It thus permits to compare each situation and correct the one with the highest index first. This method is very flexible and can be adapted to every situation. It allows emphasizing one or two of the used parameters according the safety policy of the firm who uses it. It is thus possible to justify to the authorities the choice of the prioritized actions. This method will be illustrated with two case studies. © Copyright 2016, AIDIC Servizi S.r.l.


Glor M.,Swissi Process Safety GmbH
Chemical Engineering Transactions | Year: 2016

In spiral coiled tubes electrostatic discharges - so called propagating brush discharges - have been observed during the pneumatic transfer of powders. Such discharges are rather energetic and may ignite most combustible powders. If the material in which the earthed metallic spiral coil is embedded is highly insulating, the charges resulting from friction between the powder particles and the inner tube wall cannot be quickly released to earth. As a consequence a high potential may be built-up on the inner wall giving rise to propagating brush discharges. Based on recent measurements of the charging current density and model calculations a safe upper limit of the resistivity of the material, in which the earthed coiled spiral is embedded, has been determined, below which no longer any propagating brush discharges will occur. The resistivity of a material can easily be determined from a sample in form of a cuboid or cylinder. This is however nearly impossible if the resistivity should be determined from a fully assembled spiral coiled tube without dismantling and destroying the whole tube. This paper gives guidance how this can be done by simple measurements and by interpreting the results with computer model calculations. © Copyright 2016, AIDIC Servizi S.r.l.


Glor M.,Swissi Process Safety GmbH
Chemical Engineering Transactions | Year: 2013

With 3 examples (silo filling and assessment of occurrence of cone discharges, calculation of capacitances of screws and flanges for assessment of earthing and bonding requirements and assessment of requirements for plastic hoses with a metal spiral for pneumatic transfer of powders) the usefulness and benefit of model calculations of electrostatic phenomena for the assessment of electrostatic ignition hazards is demonstrated. © 2013, AIDIC Servizi S.r.l.

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