bluuebunny/crossref_metadata_2025_split huggingface dataset:
Advantages of the new version VDI 3673. Part 1 in comparison with the chapter 7 of NFPA 68
Authors: Bruderer Reinhard E. 
Published: June 2004

AbstractVDI (Society of German Engineers) submitted a new version for pressure release of dust explosions in November 1992 which will replace the June 1979 edition. Equations are now favored and nomograph take second place. NFPA 68, 1988 edition, which was reissued in 1994 and is presently being revised already contained some newer data but used the same range of application as the 1979 VDI. Such range of application was now expanded from 1 m3 down to 0.1 m3 and from 1,000 m3 to 10,000 m3. Static activation pressure was previously limited to 0.5 bar. Now 0.1 bar to 1 bar gage can be used. Dusts with a deflagration index of 800 bar·m/s can be dealt with. Previously the limit was set at 600 bar·m/s. It is the intent of this paper to show possible savings. Pressure and flame behavior outside vented vessels will be addressed as well as the special case for pneumatic conveying.
Conflicts and decisions in the search for inherently safer process options
Authors: Hendershot Dennis C. 
Published: June 2004

AbstractIdentification of inherently safer process options is a multi‐dimensional problem. Nearly all chemical processes involve a number of processing steps. Associated with each processing step there is usually a number of hazards or hazard types, for example, high pressure, high temperature, acute toxicity, chronic toxicity, fire, explosion. A process which is inherently safer with respect to one of these hazards may be more hazardous with respect to another hazard. Several examples will be discussed, including selection of refrigerants, batch vs. continuous reaction, and solvent selection for a batch exothermic reaction. These examples illustrate the importance of a thorough understanding of all of the potential hazards in the process. Finally, some tools for evaluating process options and selecting among a group of processes with conflicting inherent safety characteristics are discussed.
The DIERS users group: Status and current activities
Authors: Fisher Harold G. 
Published: June 2004

AbstractOne hundred nine companies have formed the DIERS Users Group, a Design Institute of the AIChE, to cooperatively assimilate, implement, maintain and upgrade the DIERS methodology. The purpose of the group is to

reduce the frequency, severity and consequences of pressure producing accidentsand
develop new techniques which will improve the design of emergency relief systems.
Membership in the DIERS Users Group offers access to refinements of the DIERS technology, participation in development of additional technology, and an opportunity to share learning experiences. Membership is open to industrial or engineering organizations interested in the design, use or manufacture of emergency relief devices and systems. Semiannual three‐day technical meetings are held at various locations and feature technology presentations by member company representatives and invited speakers and discussion of the results of computational example problems and experimental round robins. There are no fees for participation.
Expressions for gravity drainage of annular and toroidal containers
Authors: Hart Peter W. , Sommerfeld Jude T. 
Published: June 2004

AbstractThe time required to drain process or storage vessels of their liquid contents can be of crucial importance in many emergency situations. Over the years, many formulas have been developed to compute the time requirements for draining vessels of various geometric configurations. These formulas typically assume gravity drainage through an orifice type of opening at the bottom of the vessel. In this article, analytical expressions are developed to compute the times required for complete drainage of annuli (both horizontal and vertical), as well as horizontal tori, solely under the influence of gravity. Annuli often form the shell side of double‐pipe heat exchange devices, while horizontal tori are often employed as distributing rings or manifolds in various mass transfer operations. Large vertical tori are sometimes used as promotional devices for advertising purposes (e.g., huge tires), but are not commonly used to contain fluids (presumably because of structural and other considerations). The drainage time expression for horizontal annuli incorporates elliptic integrals.
Thermal ignition kinetics of wood sawdust measured by a newly devised experimental technique
Authors: Chong Li V. , Shaw Ian R. , Chen X. Dong 
Published: June 2004

AbstractThe activation energies of two wood sawdusts were determined using an experimental technique based on the crossing‐point temperature concept, which was derived from the transient model of self‐heating in a solid. The two samples used in this study were treated and untreated sawdust. The activation energies measured were 106 ± 4 kJ mol−1 for the treated sawdust and 90 ± 3 kJ mol−1 for the untreated sawdust. These values are similar to those in previously published results which were obtained using the steady‐state model. The transient model provides a quicker yet sufficiently accurate method of determining thermal ignition kinetics.
Testing trnsformer oil
Authors: Turcotte Robert R. 
Published: June 2004

AbstractSuddenly, the unexpected happens—the power goes out—a critical transformer has failed. And just as suddenly, your plant is out of business. Since there are no visible moving parts there is a tendency to think that nothing can go wrong. But, preventive maintenance testing of transformers is not difficult to justify when you consider the high cost of repairs and the impact of an unscheduled outage of plant operation.
CCPS initiative to assist small and medium enterprises in improving their safety performance
Authors: Witter Ray E. 
Published: June 2004

AbstractThe Center for Chemical Process Safety (CCPS) has been concerned with the difficulty that Small and Medium Enterprises (SME's) face in improving their safety performance and in coping with EPA and OSHA regulations. Over the past several years, efforts to reach out to SME's by technical societies, trade associations, and other groups have not been fully effective, and for the most part have not reached SME's. To meet this challenge, CCPS has formed a committee to explore methods of effectively reaching SME's and to develop programs to meet their needs.
Inherent safety, health, and environmental (SHE) reviews
Authors: French Raymond W. , Williams Donald D. , Wixom Everett D. 
Published: June 2004

AbstractImplementing an Inherent SHE Review process is under way at the Exxon Chemical Company and progress is being made in the pursuit of inherently safer, healtheir, and environmentally friendly processes. The review integrates well with the company's systems for process safety management, new product development, and project execution. In addition, the Inherent SHE Review process has been quite helpful in educating the organization with regard to the appoprite use of the laboratory in developing reactive chemistry understanding during product and process development. Another benefit of the Inherent SHE Review process is the proactive involvement of industrial hygiene early in the product development and project execution processes.
Applying inherently safer concepts to a phosgene plant acquisition
Authors: Gowland Richard 
Published: June 2004

AbstractDuring the 1980's Dow Chemical acquired a urethanes business in Europe consisting of two major installations. These plants were of immediate concern due to large‐scale production and use of phosgene at one of the sites. Even though Dow has considerable experience in the bandling of chlorine, they had limited experience with phosgene in Europe. After the impact of the acquistion was assessed, a high‐level transition team was appointed by the Vice President of Manufacturing in Europe to evaluate and manage risk factors in the accquired units. Safety in manufacturing was the first item on their agenda.In many cases the activities of the transition team were driven by the principles of Inherently Safer Process Design (Substitute, Minimize or Intensify, Moderate or Attenuate and finally Simplify). The net effect of the work done since acquisition is that risk exposure to the public in the adjacent village has been considerably reduced. In addition, fugitive emissions of toxic materials have been eliminated. Economic evaluation since the projects were enacted has demonstrated that many of the activities could have been justified purely on the basis of return on investment.
Applying risk assessment principles to a batch distillation column
Authors: Woodward John L. , Moosemiller Michael D. , Chopp Robert 
Published: June 2004

AbstractSome distillation columns in the chemical industry are operated in batch mode with a fairly short operating cycle. At the end of each cycle the columns are cooled and recharged. During the cooling cycle, air will be drawn into the column by the action of a vacuum relief valve. Consequently, for a finite portion of the operating cycle a flammable mixture will exist in the column.Here we evaluate the risk posed by such an operation to see if a mitigation measure is justified. We develop a fault tree and estimate the frequency of ignition by all possible ignition sources. By comparing the risk reduction attainable by installing a lightning protection system with that attainable by using an inert blanketing system the lightning protection system is found to be the preferred solution. It provides about the same risk reduction at a lower overall cost.
Pressure relief consideration for refrigeration equipment
Authors: Leung Joseph C. 
Published: June 2004

AbstractPressure relief sizing for refrigeration equipment is considered in this paper. In particular the ASHRAE fire sizing formula [2] is critically examined and comparisons are made with methods employed in other engineering institutes. The traditional sizing approach based on vapor relief is re‐exmained in light of the recent findings from the DIERS (Design Institute for Emergency Relief Systems) work [11]. The occurrence of two‐phase discharges during relief may result in significant overpresurization of the refrigeration equipment. The purpose of this paper is to suggest a methodology adequate for most designs and which has been verified with available experimental data.
Catastrophic failure of an ammonia/air mixer
Authors: Verduijn W. D. 
Published: June 2004

AbstractKemira B.V. operates a 1200 metric tpd (100%) high pressure nitric acid plant in Rozenburg, the Netherlands since 1968. Until the incident described here occurred, operation had always been uneventful. In August 1993, however, the ammonia/air mixer suddenly burst open, releasing large amounts of air and ammonia to atmosphere. Two persons working in the plant miraculously missed being hit by the gas jet and flying debris. This paper describes the incident, its cause and measures taken to prevent reoccurrence.
Development and communication of worst‐case scenarios for the EPA risk management program
Authors: McCready David 
Published: June 2004

AbstractThis AIChE/CCPS sponsored workshop brought together a panel of experts to discuss the development and communication of worst‐case scenarios for EPA's proposed Risk Management Program (RMP) Regulation. This paper presents specific issues raised during the Workshop, such as selecting release scenarios, performing hazard assessments, and communicating the results. However, the ultimate goal is chemical accident prevention and preparedness. Findings are not attributed to the individual experts but represent the view of the discussion chairman.
EPA's risk management regulation: Communicating worst‐case scenarios
Authors: Auger John E. 
Published: June 2004

AbstractI would like to begin with a little exercise—I would like you to transport yourself back to your plant. Now, as you're back in your office, imagine for a moment that the plant emergency alarms start to go off. You catch a faint hint of ammonia as you walk to your office window. What you see can easily be described as your worst nightmare. You feel as though your heart has stopped and you freeze as if you were paralyzed. The 40 million pound (18 million kilogram) capacity double‐walled ammonia storage tank located about 200 yards (182 meters) from your office has a massive leak. Ammonia is vaporizing and being carried downwind toward the city in which you and your family live.All right—enough of the nightmare. What went through your mind? How would you react? What would be the impact on you, your family, your community? It wouldn't be good, I can assure you.Why have I tried to ruin your day by asking you to live a nightmare? For one simple reason—to show you what the Environmental Protection Agency (EPA) is going to make us all do under its proposed Risk Management Program (RMP) regulation. In fact, the EPA goes a step further. It will ask us not only to create our nightmares for ourselves, but to share them with the communities around our plants that could be impacted by our nightmare releases.
Human factors: Case histories of improperly managed changes in chemical plants
Authors: Sanders Roy E. 
Published: June 2004

AbstractChemical plant employees enjoy a safer place to work than most other places of employment. Despite the excellent overall record, there have been some tragic, catastrophic chemical plant accidents that have tarnished an excellent performance.Some of these tragedies were the result of inadvertent, unintended or poorly performed changes. This paper will attempt to convince the audience there have been too many incidents that have occurred because there were failures in managing changes in chemical plants.Medicre “Management of Change” systems can be strengthened and effective “Management of Change” systems can be made more effective through sharing simply written reports. Concise, well written case histories of past mistakes with sketches and a generous number of photos should be shared with chemical plant personnel who are responsible for day to day operations to change some plants' culture.
A flare deflagration incident at Rohm and Haas
Authors: Desai Vipul M. 
Published: June 2004

AbstractOne of the flares at Rohm & Haas plant experienced a series of three consecutive deflagrations resulting in severe damage to the flare water seal flame arrestor. The deflagrations occurred during process start up after a complete unit shutdown. This incident caused no personal injuries or off‐site impact. The incident was investigated using MCSOII (Multiple Cause System Oriented Incident Investigation) process.The root cause for the event was inadvertent addition of hot air to the flare. The hot air flow was such that the methane‐air mixture in the flare was combustible (about 11% methane). In addition, hot air raised the combustible methane‐air mixture temperature to about 300°C. The flashback velocity from the flare tip is a strong function of process gas temperature and is much higher at elevated temperatures. Thus, the downward flame front velocity was greater than the upward methane‐air mixture velocity and caused flashback. The first flashback possibly damaged the water seal such that the water seal flame arrestor lost its functionality and the connector pipe, which brings gases from knockout drum through the water seal, was open (See Figure 1). The next two flashbacks resulted in deflagrations in the knockout durm through the open connector pipe. Thus, the key recommendation to avoid a similar incident is to eliminate hot air flow to the flare.The key learning from the above incident is that flashbacks are possible when process gas is hot. We would like to extend this learning to other flares and urge a further study of all flares for possible flashback scenarios. A key action point from this incident is to perform a HAZOP on other possibilities of FLASHBACK in the flare. This will be done by performing flashback calculations on all possible flaring scenarios in the flare.
Some electrostatic considerations in the transportation of flammable liquids
Authors: Pratt Thomas H. , Atharton John G. 
Published: June 2004

AbstractThe transportation of flammable liquids in bulk quantities is a common operation in the chemical industry. Therefore a rather comprehensive set of regulations, standards, and recommended practices exists which govern how these operations should be performed. When transportation operations are performed in strict accordance with the directions given, occurrence of inadvertent ignitions have been rare, if nonexistent. On the other hand, there have been occasions when seemingly slight and innocuous deviations from the guidelines have been incorporated into an operation, resulting in catastrophic incidents. This paper discusses some of the guidelines concerning electrostatic ignitions of flammable liquids and illustrates specific case histories where such deviations have led to accidents. Two marine incidents, one rail car incident, and two tank truck incidents are presented in detail to amplify why strict adhrence to the regulations, standards and recommended practices is vital in operations where flammable liquids are transported.
Dust cloud characterization and its influence on the pressure‐time‐history in silos
Authors: Hauert F. , Vogl A. , Radandt S. 
Published: June 2004

AbstractUsing VDI 3673 or NFPA guidelines for venting we distinguish between a homogeneous and inhomogeneous dust distribution in principle. Experiments were conducted in a 12 m3‐silo to measure the dust distribution, turbulence and the reduced explosion pressure using three different ways of generating the dust/air mixture: ring nozzles with pressurized dust chambers [1] (homogeneous distribution), [2] pneumatically fed vertically downwards [2] and tangentially [3]. Additionally, the dust feeding rate, the conveying velocity and the ignition position was changed. The reduction of the conveying velocity and therefore the decrease of the RMS turbulence velocity will cause a strong reduction of the explosion pressure and the pressure rate, respectively. The results show that the dust concentration in the pneumatically filled silo is inhomogeneous. However, the RMS turbulence velocity and the reduced explosion pressure for the homogeneous distribution and the vertical filling are of the same order. In comparison, the tangential feeding results in lower values. The calculations for the pneumatical vertical filling according to VDI 3673 guideline (inhomogeneous distribution) underestimate the resulting pressure for small vent areas, but the equations for the homogeneous distribution cover the experimental data.
Research needs for process safety technology
Authors: Howard Walter B. 
Published: June 2004

AbstractMuch process safety technology has been developed through the years and now serves as the basis for present day design standards for process safety in the process industries. This has come about through carefully executed research. Much of this research has had to be done on large scale in order to fully develop and test the technology for dependable correlations necessary to establish design bases. Especially noteworthy are the design guides now available for minimizing hazards of sudden high pressure development by uncontrolled combustion inside process equipment and inside buildings. Very extenstive large scale research was necessary for developing these design guides.Despite the process safety technology and design standards available today, much more is yet needed. As in the past, development of the necessary technology will in some cases require large scale research. This paper discusses some of the major research needs in three areas, as follows:
Exothermic runaway reactions
Uncontrolled combustion
Miscellaneous research needs
Risk guidelines as a risk management tool
Authors: Hendershot Dennis C. 
Published: June 2004

AbstractQuantitative risk analysis (QRA) is a valuable tool for understanding and managing risk in the chemical process industry. QRA is most useful when used to evaluate the impact of design alternatives on facility risk (comparing the risk of one design option to one or more alternatives). QRA also determines the major contributors to facility risk, so that efforts to manage and reduce that risk can be directed to areas where they will have the largest impact and be the most cost effective. However, it is inevitable that the use of a tool which generates a numerical estimate of risk will raise questions as to the tolerability of that estimated risk. The use of quantitative risk guidelines as one tool in the risk management process will be discussed.“Wise Men Foresee Calamity in Order the Better to Bear it.”—Attributed to King Arthur at his Coronation by Geoffrey of Monmouth (c. 1136) in Histoiria regum Britanniae[1]
Advanced pilot technology: Ignition, flame detection and re‐ignition
Authors: Parker Jim , Guerra Romeo 
Published: June 2004

AbstractAdvances in technology relative to pilots, pilot ignition, pilot flame detection and pilot gas consumption are needed to reduce the millions of dollars lost as a result of outdated existing pilot technology. These losses are the result of damaged equipment, lost production, fuel usage, safety issues, lawsuits and in some instances jeopardizing personnel.This paper briefly discusses the existing pilot technolgy including pilot ignition and pilot flame detection, the economic impact on the users, and new developments in pilot technology.Over the past decade the major combustion companies have been required by consolidation of plants and the introduction of new Environmental Regulations to concentrate their Research and Development resources on the design of Flares and Burners with higher release rates, increased smokeless capabilities, and lower generation of NOX and CO. This has resulted in minimal Research and Development efforts by the major combustion companies directly relating to the design and improvement of pilots and pilot flame detection.Pilots, ignition and pilot flame detection technology has been forced to take a back seat to those more pressing issues. This has resulted in much concern by the operators of pilots regarding flame stability, ignition methods, reliability, gas usage, and safety. The industry has been forced to accept pilots, ignition and pilot flame detection equipment with outdated technology which has caused losses in the millions of dollars. The most critical component of a flare or burner is the pilot which ignites the vented high pressure relief gas from flares, and the gases or oil released through a burner to create a heat source for various plant processes.
Boiler incident directly attributable to PSM issues
Authors: Mannan Sam 
Published: June 2004

AbstractProcess Safety Management (PSM) programs are expected to reduce the probability and severity of hazardous incidents. This paper presents a real life incident that occurred in a plan before a PSM program was put in place. A detailed description of the incident is provided with appropriate discussions of noncompliance with the PSM rule. Finally, the paper provides a theoretical scenario where a fully operational PSM program would have prevented the incident. The case history and discussion provided in this paper also reinforces the concept of maintaining process and equipment integrity through multiple barriers of safety. A fully operational PSM program represents such a multiple barrier safety systems.The incident occurred in a high temperature boiler in a process plant. The incident was caused by a sequence of four occurrences that combined to cause the boiler to lose water level and have serious internal and tube damage. The problem was not detected until a mechanic who was going to work on the feed pump realized that there was flames coming out of the boiler stack. The mechanic told the operator about the problem and the boiler was manually tripped. The boiler feedwater pump was not blocked in until 30 minutes after the incident was over. If this pump was started during or directly after the incident, the addition of boiler feedwater to the over‐heated boiler would have caused an explosion. At the time the incident was reported there were 8–10 employees in the area of the boilers.