bluuebunny/crossref_metadata_2025_split huggingface dataset:
Physical modeling of water sprays—comparison against field operations
Authors: Ratcliff Michael A. , Petersen Ronald L. , Schatz Klaus W. , Heskestad Gunnar 
Published: June 2004

AbstractThis paper discusses the procedure developed for simulating water sprays at a reduced scale (i.e., physical modeling) and, more impotantly, compares the model spray characterstics to corresponding full scale spray characteristics. An ideal physically modeled spray would simulate actual spray momentum, water volume flow rate, air entrainment rate, discharge water pressure, spray angle, spray pattern and drop size distribution. Full scale measurements or estimates of air discharge velocity, momentum, entrainment rate and drop size distributions were obtained for two types of sprays at two discharge pressures, various spray angles and at a 500 gpm flow rate. Physical modeling was conducted to simulate the full scale nozzles at a 1:50 scale reduction using commercially available spray nozzles. Measurements of spray momentum, volume flow rate and air entrainment rate were obtined for a subset of spray angles used in the full scale testing. Particle size distribution was not measured since it was considered of secondary importance in the simulation. The results of the study showed that model and full scale momentum, volume flow rate and air entrainment rates compared well with corresponding full scale observations (i.e., within 10 percent for momentum, 20 percent for volume flow rate and 25 percent for air entrainment rate). The results indicate that the method used for simulating water sprays is valid and that the model sprays adequately simulate the mechanical action of full scale sprays on vapor clouds. The results provide evidence that physical modeling can be used to evaluate the effectiveness of water sprays as a mitigation technique.
Frequency estimates for transport‐related hydrofluoric and sulfuric acid release scenarios
Authors: Medhekar Subodh R. , Gekler Willard C. , Bley Dennis C. 
Published: June 2004

AbstractAn analysis was performed to predict the frequency of release associated with transportation scenarios for four refineries and a chemical plant in the South Coast Basin using hydrofluoric acid (HF) in the alkylation process/ chemical process. The analysis considers two settings. The first is the set of ongoing HF transportation scenarios, and the second is a projected set of HF and sulfuric acid transportation scenarios if the HF alkylation units of the refineries are replaced by sulfuric acid alkylation units.
Management of change—the systematic use of hazard evaluation procedures and audits
Authors: Sankaran N. 
Published: June 2004

AbstractProcess Safety Management is the application of management systems to the identification, understanding, and control of process hazards to prevent process related injuries and incidents. PSM activity has been thrust into the limelight with the promulgation of the OSHA rule, 29 CFR 1910.119, which went into effect on May 26, 1992. The practice of PSM is covered under several distinct elements, which are common to OSHA and other similar programs such as the API‐RP 750 (Management of Process Hazards). One of these important elements is the management of change. In its conventional sense, change can cover modifications to equipment and procedures. However, for purposes of this presentation I have defined change as modifications to an organization and work culture that may affect process safety.In what follows I plan to illustrate how one company affected a change in safety culture and manages change to achieve its objectives in Process Safety Management excellence.
The corporation and the community: Credibility, legitimacy, and imposed risk
Authors: Rosenthal Isadore 
Published: June 2004

AbstractLarge segments of society no longer trust firms or government in regard to pronouncements on what is safe. Because of this distrust, particularly in regard to the chemical industry, the public has questioned many firms right to operate in their community and demanded and obtained increased rights for individuals to intervene directly in decisions by firms that might affect them.Chemical firms must establish or restore their credibility and social legitimacy in order to maintain their social franchise to operate. At a minimum, this requires an understanding how the firm's stakeholders view the firm's imposition of risks on them and their families and the engagement of these stakeholders in discussions about the firm's products and operations and the risks attendant on its presence in the community. Some chemical firms have formed community advisory councils as a way of accomplishing this rapproachement. However, they have found that a community council may have its own agenda, forcing the firm to provide information and deal with issues it would have preferred to avoid.
Transient flow phenomena and reaction forces during blowdown of gas at high pressures through relief lines behind rupture discs
Authors: Perbal R. 
Published: June 2004

AbstractIn general, rupture discs are designed to give a virtually instantaneous pressure relief opening to a relief system at a predetermined pressure. For safe design of pressure relief systems, consideration must be given to the sizing and the specification of the rupture disc but also to the reaction forces that result when a gas is discharged. These reaction forces can be excessive in the case of venting at high pressures.When a disc ruptures, a shock wave propagates through the gas in the piping behind the rupture disc. This exerts a transient reaction force on the pressure relief system. In the case of steady supersonic flow choking often occurs at one or more points in the pressure relief line and a shock is formed in the pipe. The pressure in the relief line may increase considerably during blowdown as a result of choking at the end of the pipe. Depress‐surization experiments were conducted with nitrogen at high pressures.The results of the pressure measurements in the piping during blowdown are compared with exploratory calculations. The reaction forces exerted on a pressure relief system can be assessed from the pressures and the mass flow rate of the gas as a function of time. For safe design of pressure relief systems, both steady‐state flow reaction forces and the initial transient forces should be considered.
Managing the PHA team
Authors: Dowell A. M. 
Published: June 2004

AbstractLock 8 people in a room for 10 days with the charge to do a PHA (Process Hazard Analysis), to develop missing Process Safety Information, to make recommendations to reduce risk and to document all their work—What will result? Frustration and fatigue, or comradeship and accomplishment? The PHA effort must be managed to meet the objectives of the OSHA rule for Process Safety Management of Highly Hazardous Chemicals, and, equally important, to meet the needs of the individuals serving on the team. This paper presents learnings from over 14 years of leading and serving on HazOp teams. Here's how to get the best from the PHA experience.
Case histories of some power and control‐based process safety incidents
Authors: Griffin M. L. , Gurry F. H. 
Published: June 2004

AbstractThis paper presents some case histories of power‐and control‐based process safety incidents and near misses involving the Procter & Gamble Company and its affiliates.A key part of our Process Safety Program is to learn from the incidents that we and others experience. Incidents in our facilities are investigated for basic cause, and the learnings are shared with other plants. In some cases it is necessary to change our design practices and standards. We believe that thorough incident investigation is a major tool in our continuous improvement efforts. Each of these events had the potential to cause serious personnel injury and/or major production losses. Fortunately, these incidents did not produce any reportable personnel injuries.We are sharing these case histories of process safety incidents and near misses here so others can learn from them. The six incidents reviewed in this paper all resulted from the failure of a power or control system. We will review what happened, what we learned, and make recommendations to avoid future incidents like them. We hope that this will help avoid similar, possibly more serious, incidents in other facilities.
A comprehensive program for preventing cyclohexane oxidation process piping failures
Authors: Sadler Donald L. , Matusz Brian T. 
Published: June 2004

AbstractIn 1971, the Cyclohexane Oxidation Unit at the Monsanto Plant at Pensacola, Florida, suffered a pipe rupture that resulted in the formation of a cyclohexane vapor cloud of major proportions and disastrous potential. Catastrophe was averted because there was no ignition of the cloud.The incident, plus past and present piping system remediation programs undertaken to prevent future occurrences as described in this article. The current program involves a comprehensive survey of critical piping systems utilizing flexibility analysis, acoustic emission testing, radiographic and ultrasonic inspection, HazOp safety studies, and distributed process controls to properly maintain and operate the critical piping systems.
Spill containment and destruction of a reactive, volatile chemical
Authors: Weirick M. L. , Farquhar S. M. , Chismar B. P. 
Published: June 2004

AbstractA risk reduction project at a small Union Carbide Corporation facility included an unusual design feature that is the main subject of this paper. The project included a concrete secondary containment pit to contain and reactively destroy spilled material. The pit was designed so that the worst‐case spill scenario of flow conditions, ambient temperature, and wind stability would not result in emissions from the pit with fenceline concentrations that exceed regulatory limits. The containment pit is not the entire risk control system, but it is the final component of a multi‐layered risk mitigation system. To place the containment pit in context, the entire scope of the episodic risk control strategy is reviewed.
The real costs of risk analysis
Authors: Rosenthal Isadore , Lewis Philip G. 
Published: June 2004

AbstractWith the promulgation of the recent OSHA process safety management standard (PSM) and the proposed EPA rule on Risk Management Programs (RMP) for chemical accident prevention there is a shift in the incremental costs incurred by a firm from voluntary use of state‐of‐the‐art chemical process quantitative risk analysis (CPQRA).
Static electricity in pneumatic transport systems: Three case histories
Authors: Pratt Thomas H. 
Published: June 2004

AbstractThree incidents, two explosions and one near miss, of electrostatic ignition of dust suspensions in pneumatic transport systems are reported. The incidents actually occurred in three separate systems; but, because of legal implications, they are reported in terms of one generic system. Incident A describes a near miss where there were some ungrounded ducts in the system. Incident B describes an explosion during the filling of an intermediate bulk container with a powdered material. Incident C describes an explosion in a bag filter (bag house) after some two years of operation. The discussions include some basic preventive measures which should be taken in similar systems to prevent the buildup of electrostatic potentials.
Low cooling tower level causes evacuation
Authors: Dowell A. M. 
Published: June 2004

Abstract
Is a utility part of the plant safety systems?
Is up‐to‐date documentation of the utility system needed?
Two operating units were evacuated during a small release of a toxic compound. The release occurred during a refrigeration system outage caused by low level in the cooling tower. Among the causes of the low cooling tower level was out of date documentation for the cooling tower makeup water supply.This paper presents a multiple cause, system oriented incident investigation of the release. Additional causes and recommendations for improvement are included in the paper.
Flammability of metals and other elemental dust clouds
Authors: Cashdollar Kenneth L. 
Published: June 2004

AbstractThis paper reports results from a U.S. Bureau of Mines study of the flammability of various metals and other elemental dusts dispersed in air. The data are useful for evaluating the explosion hazards in the minerals and metals processing industries. The dusts studied included boron, carbon, magnesium, aluminum, silicon, sulfur, titanium, chromium, iron, nickel, copper, zinc, niobium, molybdenum, tin, hafnium, tantalum, tungsten, and lead. The dusts were chosen to cover a wide range of physical properties—from the more volatile materials such as magnesium, sulfur, and zinc to the highly “refractory” materials such as carbon, niobium, molybdenum, tantalum, and tungsten. These flammability studies were conducted in the Bureau of Mines 20‐L explosibility test chamber, using strong pyrotechnic ignitors. The parameters measured included the minimum explosible concentrations, maximum explosion pressures, and maximum rates of pressure rise. All of the elemental dusts ignited and burned as air‐dispersed dust clouds except the nickel, copper, molybdenum, and lead. In general, the dusts with the highest explosion pressures and rates of pressure rise were also those with the highest calculated, adiabatic flame temperatures and/or the ones that vaporized most easily, but this was not true in all cases. The effect of particle size on flammability was studied for the aluminum and iron dusts. The minimum explosible concentrations were relatively independent of particle size below 30 μm, but the highest explosion pressures and rates of pressure rise were found at the finest sizes tested.
Aspects of emergency relief design for reactive systems
Authors: Goetz David D. , Sawrey Jeffrey S. 
Published: June 2004

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 model.
Dust and hybrid explosibility in a 1 m3 spherical chamber
Authors: Chatrathi Kris 
Published: June 2004

AbstractThe dust explosibility characteristics of Lycopodium, Cornstarch, Pittsburgh Bituminous Coal and Calcium Sterate were measured in a 1 m3 spherical 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.
Catastrophic failure of a liquid carbon dioxide storage vessel
Authors: Clayton W. Edward , Griffin Michael L. 
Published: June 2004

AbstractThis article describes the catastrophic failure of a liquid CO2 storage 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 CO2 vessels 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 CO2 storage systems into standard Design Practices.
Studies about the influence of turbulence on the course of explosions
Authors: Scheuermann Klaus P. 
Published: June 2004

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 sb on the turbulence intensity u′ is discussed for the closed and the vented vessel.
A methodology for assessing catastropic damage to the population and environment: A quantitative multi‐attribute approach for risk analysis based on fuzzy set theory
Authors: Christen P. , Bohnenblust H. , Seitz S. 
Published: June 2004

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 this paper.
An advanced method for the estimation of reaction kinetics, scaleup, and pressure relief design
Authors: Melhem G. A. , Fisher H. G. , Shaw D. A. 
Published: June 2004

AbstractThis paper presents an advanced modeling approach which significantly improves predictions of reaction rates and critical data that engineers need to design effective pressure relief systems. Ideally, pressure relief systems are sized exactly for the reaction characteristics of the chemicals in the vessel. However, with many chemicals and chemical mixtures, reaction chemistry is difficult to characterize because the individual components interact in complex ways. Furthermore, the high cost and risk of full‐scale reactivity experiments make test data scarce. Chemical engineers bridge this gap in part with small‐scale tests and modeling computer codes such as the one developed by the Design Institute for Emergency Relief Systems (DIERS). The comprehensive approach developed in this paper provides a reliable design basis for difficult systems, including highly energetic and nonideal reactions, systems with continuing reactions in piping and containment vessels, and systems where homogeneous bubble collapse caused by rapid depressurization could cause a catastrophic vessel failure. We first examine possible mechanisms for catastrophic vessel failure and associated consequences. Next, we outline a detailed approach for emergency relief system design and reactivity testing.
A method for implementing a piping inspection program
Authors: Matthews Peter B. , Beberman Julie A. 
Published: June 2004

AbstractRecent catastrophic piping failures dramatically demonstrate the importance of implementing a piping program. Piping system leaks and ruptures have caused death and injury to plant workers, firefighters, and the public. Significant financial consequences due to unexpected downtime and property damage have plagued industry. The environment has also suffered from the release of toxic chemicals. In the chemical industry, roughly 30% of the catastrophic losses have been historically attributable to piping failures.
Critical temperatures for the thermal explosion of liquid organic peroxides
Authors: Kotoyori Takashi 
Published: June 2004

AbstractA procedure is presented herein to calculate the critical temperature for the thermal explosion (hereafter symbolized as Tc) of an arbitrary quantity of thermally unstable liquid placed in an arbitrary container, by measuring experimentally the rate of heat transfer from the container as well as the rate of heat generation of the liquid sample in temperature increments of 1.25 K. The Tc values of ten liquid organic peroxides are then calculated in accordance with the above procedure for the practical situation arising when the liquids are either in a Dewar flask which is used in the BAM (Bundesanstalt für Materialforschung und ‐prüfung, Berlin) heat‐accumulation storage test or in a 5‐ or a 10‐L polyethylene container which are used by the peroxide manufacturing company for carrying 5‐ or 10‐kg quantities of liquid organic peroxides to the users. For the Dewar flask, the corresponding measured values were available, and they showed good agreement with the calculated ones. The new findings introduced in this article are that there is a prospect that one can predict the result of a BAM test by calculation for a solid as well as for a liquid; in addition, for liquids, there is also a possibility that one can calculate the Tc value of an arbitrary quantity of liquid placed in an arbitrary container.