摘要:

AbstractAn approach is presented to accurately design emergency relief systems for even the most complex chemical reactions. Two examples illustrate how large differences in relief requirements can result if small, but important, aspects of the calorimetry data are overlooked. Although both simple and rigorous kinetic models may seem to predict calorimetry data reasonably well, these examples demonstrate the importance of well‐designed experiments, optimization algorithms, rigorous kinetic modeling, correct physical properties, and dynamic simulations.The first example shows how the inclusion of a subtle equilibrium reaction in the kinetic model will allow venting of an intermediate species, decreasing the reactant available for the highly exothermic irreversible reaction. The second example emphasizes the importance of a rigorous model for the decomposition of a large molecule where bond cleavage can occur between repetitive groups.This example takes advantage of the tempering effect of intermediate decomposition products which are accounted forwith the rigorous mode

ISSN:1066-8527    

DOI:10.1002/prs.680130402

出版商:American Institute of Chemical Engineers    

年代:1994

数据来源: WILEY

摘要:

AbstractThe dust explosibility characteristics of Lycopodium, Cornstarch, Pittsburgh Bituminous Coal and Calcium Sterate were measured in a 1 m3spherical explosion chamber at ambient pressures, ambient temperatures and at three different turbulence levels. Explosibility parameters measured were the maximum pressure, maximum pressure rate of rise and the initial pressure rate of rise. Propane explosibility and Hybrid explosibility (Cornstarch in the presence of propane) were also measured. For the hybrid system, the lower limits of explosibility and the effect of low propane concentrations on the explosibility of optimum Cornstarch concentrations were investigated. Finally, a relationship between maximum pressure rate of rise and initial pressure rate of rise was sought in order to lay a foundation for explosion suppression and explosion venting engineering methodologies.

ISSN:1066-8527    

DOI:10.1002/prs.680130403

出版商:American Institute of Chemical Engineers    

年代:1994

数据来源: WILEY

摘要:

AbstractThe VDI Guideline 3673 “Pressure Release of Dust Explosions” published in June 1979 [1] describes one of the possible constructional protective measures against the effect of dust explosions and provides details on the venting area requirements of vessels and silos. Thanks to the results of extensive explosion trials conducted in the last ten years on the problems addressed above, important gaps in our knowledge have been filled and new findings gained which have made a revision of the above guidline necessary. The contents of the new version are reported and attention drawn to modifications compared with the first vers

ISSN:1066-8527    

DOI:10.1002/prs.680130404

出版商:American Institute of Chemical Engineers    

年代:1994

数据来源: WILEY

摘要:

AbstractThis article describes the catastrophic failure of a liquid CO2storage vessel and the chain of events that contributed to this incident. This incident happened in Procter&Gamble GmbH's citrus process in Worms, Germany. Three fatalities, over $20 million in property damage, and three month's lost production resulted.Initially less than one‐fifth of the storage vessel was available for examination. The force of the explosion had propelled most of the vessel into the nearby Rhein River. The unavailability of the other parts of the vessel seriously hampered the incident investigation and prevented correct determination of the basic cause of the failure. Later recovery and inspection of additional parts of the tank allowed the investigation team to determine the correct basic cause.The results of the inspections conducted on other liquid CO2vessels are covered. These inspections resulted in most of these vessels being removed from service. Other actions taken to prevent similar incidents include:Elimination of the use of carbon dioxide in many non‐critical applications.Development and adoption of specific Company design requirements for liquid CO2storage systems into standard Design Practi

ISSN:1066-8527    

DOI:10.1002/prs.680130405

出版商:American Institute of Chemical Engineers    

年代:1994

数据来源: WILEY

ISSN:1066-8527    

DOI:10.1002/prs.680130406

出版商:American Institute of Chemical Engineers    

年代:1994

数据来源: WILEY

摘要:

AbstractThe Fire and Explosion Index (F&EI) is one of the most widely used hazard indices for chemical process plants. It was developed by The Dow Chemical Company in 1964 and has been improved, enhanced and simplified through the publishing of six editions. This paper describes the latest 7th edition and the improvements it contains. The F&EI is to serve as a guide for evaluating the hazard potential for separate major units of chemical process plants, is to aid in determining the consequences of a fire or an explosion and is to help determine appropriate loss prevention features to be used.Efforts have been made to make the task of completing the F&EI form easier and the results more consistent based on the most current and accurate material property data. Some of the major features of the revised F&EI are:Improvement of readability and corrections to previous edition.Addition of F&EI versus Degree of Hazard table.Major upgrading of data table which gives key chemical properties and materials factors.Revised, streamlined F&EI forms available in computer spreadsheet form.Improvement in data plots with equations developed for ease of calculations.Adjustments and updating of credit factors and check lists.The main purpose for creating the 7th edition is to update information, procedures and data to make the F&EI and auxiliary calculations more accurate and easier to perform. There are no fundamental changes in the methodology. Use of the newFire&Explosion Index Hazard Classification Guideshould lead to better determination of this important hazard index which is a valuable tool for analyzing risks for chemical process plants and selection of appropriate measures. The revised F&EI guideline will be made available as an AIChE publication as it has been since 1966.

ISSN:1066-8527    

DOI:10.1002/prs.680130407

出版商:American Institute of Chemical Engineers    

年代:1994

数据来源: WILEY

摘要:

AbstractTurbulence has a decisive influence on the course of dust and gas explosions. The aim of this study is to understand this influence in more detail and thereby to improve the assessment of explosions in technical systems.Studies for maize‐starch/air mixtures (c = 750 g/m3) and for propane/air mixtures (λ = 1) are carried out in a 1 m3‐vessel. Ordinary in testing vessels the turbulence will be generated by a perforated dust dispersion tube. In order to generate a turbulence field as homogeneous as possible, a perforated plate is moved through the vessel. The turbulence decay is used to set the effective turbulence at the ignition point.From the experimentally determined pressure/time courses, important quantities of turbulent combustion are calculated using a calculation model. The dependency of the turbulent flame speed sbon the turbulence intensity u′ is discussed for the closed and the vented

ISSN:1066-8527    

DOI:10.1002/prs.680130408

出版商:American Institute of Chemical Engineers    

年代:1994

数据来源: WILEY

摘要:

AbstractNew regulations in 1991 (HM‐183) have required that materials may not be coshipped in the same cargo tank motor vehicle if, as a result of their mixing “…an unsafe condition would occur, such as an explosion, fire, excessive increase of pressure or heat or the release of toxic vapors.”In order to determine the potential hazards resulting from inadvertent mixing which would result in a hazardous condition, a technically sound evaluation procedure was needed which was reasonably accurate as well as time and cost effective. This required both thermodynamic (heat and/or pressure released) and kinetic parameters (is the energy released immediately or does it take a day, week, month etc.?). A model has been developed using the SimuSolvA Trademark of the Dow Chemical Co.computer program and Microsoft's EXCEL™ spreadsheet which combines the kinetics and thermodynamics for a reaction with the heat transfer parameters for a given tanker truck. Real heat loss data were then obtained for a typical compartmentalized tanker truck for use in the model. The rates and enthalpies for reaction input can be taken from ARC, DSC, or literature data. Since a very large number of binary combinations of potentiai mixtures are possible, materials were grouped according to chemical functionality. A model compound was chosen to represent each functional group. These materials were chosen to best represent the worst‐case reactivity of the group, unimpeded by steric or other factors. A single material/formulation could be classified into more than one grouping. Representative data were complied from experimental studies (Mixing calorimetry, ARC, DSC, etc.) and a wide variety of internal and external literature sources. Where outside sources described a potential incompatibility between groups, the data were gathered on model compounds and input into the model to determine pertinent compatibility. A compatibility chart was constructed for the resulting potential binary mixtures based upon th

ISSN:1066-8527    

DOI:10.1002/prs.680130409

出版商:American Institute of Chemical Engineers    

年代:1994

数据来源: WILEY

摘要:

AbstractA worldwide discussion about catastrophic events in the chemical process industry was initiated by major disasters such as Seveso, Flixborough and Bhopal. As a result of the disaster in Basel (Switzerland), known as “Schweizerhalle,” special regulations regarding catastrophic events were set up in Switzerland. In this context a method for the quantitative evaluation of the risks associated with stationary chemical installations was developed. In the past, only one attribute for assessing the magnitude of impact, namely the number of fatalities, was considered risk analyses. In this paper a methodology for an extended damage assessment of the overall impact of an event including damage to man and animals, to ecosystems and natural resources, and to property is presented. The crucial question is how the overall impact can be represented by a limited number of indicators. Two basic questions are also important in this context: First, how can we assess and quantify the inherent fuzziness of the notion “catastrophe?” Second, how can we describe the impact by using different indicators in a multi‐dimensional way? The main aspects of this method, namely the indicator appraisal and the linking of the indicator values to a single disaster value are discussed in t

ISSN:1066-8527    

DOI:10.1002/prs.680130410

出版商:American Institute of Chemical Engineers    

年代:1994

数据来源: WILEY

ISSN:1066-8527    

DOI:10.1002/prs.680130401

出版商:American Institute of Chemical Engineers    

年代:1994

数据来源: WILEY