bluuebunny/crossref_metadata_2025 huggingface dataset:
A flare deflagration incident at Rohm and Haas
Authors: Desai Vipul M.
Published: June 2004

One 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

The 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

Using 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

Much 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

Quantitative 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

Advances 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

Process 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.
Pressure relief systems: The sensible approach to verification and documentation
Authors: Ahmad Aman A.
Published: June 2004

As process safety and risk management stewards, one of the first things we should be concerned about is the reliability of our pressure relief system. The importance of pressure relief systems to the CPI and HPI is paramount. Yet this issue has frequently not received the recognition it deserves, even though it is mandated by OSHA 1910.119. Although relief systems presently in service at process facilities may have been adequate for the original plant design, it is likely that the same systems are now being exposed to higher capacities and different relief scenarios. Therefore, verification of the adequacy of these systems should have been done concurrently with operational changes. Many in industry have only recently recognized this, and are striving to incorporate such procedures in their engineering standards. Others are still uncertain how to proceed, and two obvious questions that come to mind are (1) what is the most logical way for us to verify the adequacy of an existing system?, and (2) how to we document this information systematically, in order to avoid replicating our efforts every time we make a process modification?
Risk based package design
Authors: Freeman Raymond A. , Kleffner Joseph W.
Published: June 2004

The shipment of hazardous chemicals can pose signficant risk to the general public and the environment. These shipments are made in a variety of packages ranging from small bottles to large tank trucks, tank cars, and barges. However, the many standards and regulations that have been established to govern the design and use of these packages define what many consider to be the minimum requirements for risk management. This paper presents a methodology that can be used to more thoroughly identify the risk minimization options and verify the design of a package for a particular service. This method is based on the concept of a threat analysis of the proposed movement of the hazardous chemical. The threat analysis looks for unusual (but realistic) threats to the package that may result in the release of the hazardous chemical to the environment. Such unusual threats may include events such as: Dropping of the package during loading; Accident enroute; External fire during shipment; Random acts of vandalism (using the package as a practice target); Puncture (fork lift collision with package, rail/truck accident); Crushing (sudden starting or stopping). By conducting an engineering analysis of the strength and ability of the container to withstand these unusual events, a package design that can withstand the threats indentified in the threat analysis can be defined.
The potential of sufficient static electricity for ignition during tanker washing
Authors: Chopp Robert , Pape Ronald
Published: June 2004

Waste‐derived fuel is an environmentally friendly method for destroying waste and recovering the energy value it contains. The fuel is characterized as a mixture of various solvents with a flashpoint in the flammable range. In addition to these solvents, the waste fuel contains solid material. During the transfer of this material to storage tanks, some of the solid material is is left behind in the tankers and rail cars. The ideal solution to remove this solid material is to wash the tank vehicle with the same waste fuel. With the waste fuel being in the flammable range, there is a concern about the washing operation causing ignition due to static electricity.

Scaled experiments were conducted to assess the potential for static electricity to cause ignition. Although several ignition mechanisms were assessed, this paper is concerned with the charged mist caused by the high velocity solvent jet impinging on the tank wall. Isopropyl alcohol, mixed xylenes, and mineral spirits were evaluated. An aerosol electrometer was used to measure charge per unit volume of mist sampled. Discharge generation was assessed using an analytical model which estimates electric field corresponding to measured charge density for various configurations.
Using the CCPS guidelines for chemical transportation risk analysis
Authors: Bendixen Lisa , Freeman Raymond A. , Hendershot Dennis
Published: June 2004

Transportation of hazardous chemicals as raw materials or products from chemical process facilities presents special hazards. Recently, the Risk Assessment Subcommittee (RASC) of the AIChE Center for Chemical Process Safetly (CCPS) completed a three‐year project which has been published in a CCPS Guidelines Series entitled Guidelines for Chemical Transportation Risk Analysis. The major themes of the book are summarized in this paper and the methods and techniques used in evaluating the risk of movement of hazardous chemicals are described. Guidelines for Chemical Transportation Risk Analysis covers methods that can be used to evaluate the risk of movement of a hazardous chemical by rail, barge, truck, pipeline, and ocean‐going vessel. A simple example is presented using the methods discussed in the guidelines.
Study on safety evaluation and operational design for startup
Authors: Batres Rafael , Lee Sanggyu , Lu Ming Liang , Naka Yuji
Published: June 2004

Aiming at improving the safety of process startup, this paper integrates safety evaluation into an operational design methodology which designs operable processes by proposing alternatives, examining process operability and modifying plnat structures and operating procedures. Safety analysis is used as a key component of design evaluation for examining potential hazards during startup. Potential hazards are eliminated by modifying both plant structure and operating procedures. Issues for both methodology and implementation of a prototype in G2 are discussed. Finally, the system is applied to an industrial hydrodesulfurization process.
Next generation risk management
Authors: Schumacher Robert , Pitblado Robin , Selmer‐Olsen Ståle
Published: June 2004

The management of safety, quality and environmental issues covers a complex set of interrelated issues of concern to society and industry. Traditionally an engineering approach has been adopted for the management of risk; the development of technical standards, operations and requirements. Recently, industry leaders have begun to realize that real progress will be made only throgh effective risk management systems. This paper presents a few of the key requirements for improving risk management and risk analysis. By improving the way risk analysis is used for decision support, improving hazard identification exercise, while incorporating site specific properties of design, condition, operation and management into an analysis, it is possible to improve the value of current risk management techniques.
Trading cost against safety: The structure of people's beliefs
Authors: Allen P. T.
Published: June 2004

The paper addresses issues arising from a consideration of the views people express about the legitimacy of, and appropriate levels at which, cost may be traded‐off against risk, in the context of investment in the safety of chemical industry plant. The discussion is based on the findings from a number of studies, in the UK and in Belgium, which included trade‐off judgements by the public and members of various interest groups. Some general features of responses are noted and their implications for policy are discussed.
Mechanism and kinetics of decomposition from isothermal DSC data: Development and application
Authors: Chervina Sima , Bodman Glenn T.
Published: June 2004

A method for deriving kinetic equations of decomposition of thermally unstable chemicals from isothermal DSC experiments was developed. The following steps are included in the method:

collecting experimental data in the form of heat flow versus time from isothermal DSC experiments at three or four different temperatures, and in the form of temperature versus time from one adiabatic ARC experiment,

converting the experimental DSC data into concentration versus time data using DSC Isothermal Kinetics Data Analysis Program, Part 1 (TA Instruments),

fitting a specific kinetic equation to the concentration versus time data using Rate Program (Batch CAD),

calculating rate constants at the experimental temperatures using Rate Program (Batch CAD),

determining activation energy and frequency factor from temperature dependence of k,

verifying the kinetic equation by simulating adiabatic decomposition of the chemical in an ARC bomb using the derived kinetic equation and Reaction Program (Batch CAD) and comparing the simulation results with experimental.

The decomposition kinetics and mechanism for the following six groups of chemicals were analyzed: nitrobenzene, nitrosobenzene, hydrazine, and tetrazoles derivatives, alkynes ( C  C ), and monomers (H2C  C ). The first four groups were determined to decompose by an autocatalytic mechanism. Full kinetic equations were developed and analyzed for six tetrazoles. The mechanism of decomposition for all six chemicals appeared to be autocatalytic, showing various reaction orders (0.7–2.2) with respect to the chemical and the autocatalyst. Reaction orders, activation energies, and frequency factors were determined and compared for all six chemicals.
Acoustic emission on‐line monitoring of the ammonia plant NII secondary reformer exit (gas channel)
Authors: Tonheim Jan , Tveit Reidar
Published: June 2004

In 1987 and 1989 the Ammonia Plant Secondary Reformer Exit line experienced severe cracking which developed in the fusion line between the CrMo low alloy and the high alloy CrNi (Incoloy 800H) materials. The major failure mechanism was identified as “hydrogen disbonding,” due to combinations of high material temperatures, high weld stresses and too high cooling rates during plant shutdown. An undetected development of defects could not be tolerated, and after a review of applicable monitoring techniques, it was decided to install a four‐channel PC based AE monitoring system. The objective was on‐line detection of developing defects in the weld area. According to in‐house evaluation criteria the acoustic activity was verified by on‐line (high temperature) ultrasonic examination.

The safety philosophy behind the project, the AE monitoring system and the analysis programs, and the summarized experience from nearly two years of operation is presented here.
The role of the two‐phase scenarios concept in the matrix relative risk ranking procedure
Authors: Ferjenčík Miloš
Published: June 2004

A compatable accident scenario model selection is presented in order to demonstrate how matric relative risk ranking methods can be developed into a simple, efficient, effective tool. These matrix methods have the capability to provide reasonable approximations to quantitative risk analysis (QRA) methods.

The contrast between matrix method's outcome and indexing results is emphasized. The concept of a one‐phase representative accident scenario model is introduced and a one‐phase model is described.

A two‐phase representative accident scenario model is introduced as an improvement of the one‐phase model. Systematic application of the two‐phase scenario model is thought to improve matrix methods. The two‐phase model is still simple enough to be integrated into the matrix procedure and is detailed enough to support more complex modelling including plant specific knock‐on effects.
Replacement of an ammonia storage tank
Authors: Shipman John S. , Davies Ray
Published: June 2004

In June 1994, a proposed minor modification to an ammonia storage tank led to a review of its overall design and construction. This review ultimately led to the tank being removed from service and a, replacement tank being constructed.

This article describes: the design and construction of the tank; concerns that had developed in 1975, after a period of 20 years operation, consequential actions and the subsequent discovery of cracking; the 1995 fitness‐for‐service review; the options for replacement and differences between published recommendations; design issues and consequences for the choice of construction material; and the installation and commissioning of the tank.
Case histories of two incidents following process safety reviews
Authors: Howard Walter B.
Published: June 2004

This article discusses two incidents, both of which occurred after process safety reviews had taken place. Certain key recommendations were made for inherently safer operations, but the people in charge had decided not to implement them. In this connection it is important to note the three P's of safety: Safety of People, Property, and Profits. Safety hazards in a process operation can involve any or all of these. The first incident involved safety of property and profits, i.e., significant losses in both; the second primarily involved safety of profits. Both incidents occurred well before the days of OSHA and EPA.
Risk analysis of a chloralkali industry situated in a populated area using the software package MAXCRED‐II
Authors: Khan Faisal I. , Abbasi S. A.
Published: June 2004

Risk assessment, based on quantitative maximum credible accident analysis (MCAA), has been conducted for a chloralkali industry situated in the midst of densely populated coastal villages. The study has made use of a software package MAXimum CREDible accident analysis version 2 (henceforth referred to as MAXCRED‐II) recently developed by us.

Among the six different most credible accident scenarios developed using MAXCRED‐II, the one envisaging ‘confined vapor cloud explosion followed by fire ball’ (in the hydrogen storage vessel) comes out to be the worst in terms of the highest propensity for damage (overpressure, missile, heat load). It also has the potential of causing domino effect (chain of accidents). The scenario of causing domino effect (chain of accidents). The scenario of ‘continuous release of chlorine from storage vessel’ is the second most disastrous, in terms of lethal toxic load likely over a large distance (3252 meters). In summary, the study reveals that given the masses of materials stored, and the conditions in which they are stored, there is a live risk of accidents in the storage vessels that would have far‐reaching consequences. The industry thus poses a great risk to large areas of surrounding including densely populated villages (particularly Chinnakalapet and Kalapet) and the campuses of Pondicherry University and Pondicherry Engineering College.

This paper demonstrates the utilizability of MAXCRED‐II and also focuses attention on the need to bestow greater effort towards risk assessment. It is hoped that these studies will make plant managers conscious of the serious consequences that can result from accidents in their vulnerable units. Appreciation of the risk, we hope, will prompt them to develop accident prevention strategies and to put in position emergency preparedness plans to cushion the adverse impacts if accidents do occur.
QRA of chemical reaction systems: The state of the practice
Authors: Farquharson John , McNutt Scott , Paula Henrique , Roberts Michel , Waller Al
Published: June 2004

This paper discusses a quantitative risk assessment (QRA) of an exothermic chemical process. Fault tree/event tree techniques were used to estimate the frequency of runaway reactions that could result in over‐pressure and vessel rupture. The paper focuses on the current methodology used in performing this type of study, emphasizing analytical techniques that help avoid potential time‐consuming pitfalls. The challenging problem of predicting how rare sequences of events (e.g., involving failure of several engineered control and safety systems) will develop is systematically modeled using fault trees/event trees, which makes the QRA process a unique and powerful analytical tool. The results of this study provided the guidance for selecting the most appropriate action(s) to implement from a set of various design options for improving the safety of this system. Use of QRA has enabled plant management to have confidence that they are selecting the most cost‐effective safety improvement option.
Improving the effect of atmospheric stability class for dispersion modeling
Authors: Woodward John L.
Published: June 2004

Recent guidelines released by the U.S. EPA define a worst‐case scenario as a release under stable atmospheric conditions defined as Pasquil‐Gifford stability class F. Unfortunately, very few tests at F stability have been available heretofore to provide a basis for models. Recent test data with propane releases by the German research organization TUV provide a set of 60 experiments conducted specifically to define the effects of atmospheric stability class on dispersion. Of these, 25 tests were at F stability. A comparable number were at each other stability class A through E. In addition 23 tests were at wind speeds under 1.5 m/s in stable atmospheres. This paper reports on adjustments made to our models based on these new data by reducing the originally‐postulated sensitivity to stability class. In spite of considerable scatter in the TUV data, particularly between two different types of propane analyzers, the model allows us to extract information by averaging over the tests.
Transportation of hazardous wastes
Authors: Allen David J. , Wolkstein Melvin
Published: June 2004

Risk assessments have been performed to determine the risk associated with the transportation of hazardous wastes through a city. In the course of these assessments, a number of modeling issues arose relating to transportation accident rates, the characterization of incidents, the effect of thermal radiation, the impact of exposure to toxic chemicals, and the threshold for acceptable risk. This paper discusses these issues.
Determination, prevention and mitigation of potential hazards due to the handling of powders during transportation, charging, discharging and storage
Authors: Jaeger Norbert , Siwek Richard
Published: June 2004

The knowledge of the ingition behavior of dust‐air mixtures due to electrical sparks (MIE, Minimum Ignition Energy) and hot surfaces (MIT, Minimum Ignition Temperature) is important for risk assessments in chemical production plants. The ignition behavior determines the extent and hence the cost of preventive protection measures.

This paper describes the use of the minimum ignition energy and minimum ignition temperature as very important safety indexes in practice.

Based on the latest results from large scale experiments on pneumatic filling of silos with polymeric materials and new results of full scale filling tests using Flexible Intermediate Bulk Containers (FIBC) manufactured from a variety of materials, guidance can be given to ensure safe operation in different situations such as filling, emptying operations, type of powder handled.

The aim of this paper is to assist people dealing with product. It reflects the present state of the art and current knowledge of the assessment and measures associated with powder handling.
Integrating hazard analysis into the implementation of advanced process control
Authors: Seiver David S.
Published: June 2004

In mid‐1997, an Advanced Process Control (APC) scheme was implemented at a resins manufacturing complex with the goal of minimizing flare fuel gas usage while maintaining sufficient energy (BTU/SCF flare gas) to be in environmental regulatory compliance. Prior to APC implementation, the flare system was manually controlled by plant operators with minor attention paid to the minimization of fuel gas usage. Since implementation, APC has saved the plant thousands of dollars in fuel gas costs and reduced unnecessary combusted fuel gas emissions.

Hazard analysis techniques were used in the development of the control scheme. An overview of the APC used, the economic evaluation, and the hazard analysis techniques used in the project are presented here.
Application of the flammability diagram for evaluation of fire and explosion hazards of flammable vapors
Authors: Mashuga Chad V. , Crowl Daniel A.
Published: June 2004

The safest method to prevent fires and explosions of flammable mixtures in the first place. This method requires detailed knowledge of the flammability region as a function of the fuel, oxygen, and nitrogen concentrations. A triangular flammability diagram is the most useful tool to display the flammability region, and to determine if a flammable mixture is present during plant operations.

This paper describes how to draw and use a flammability diagram. A procedure to estimate the flammability region using the available and sometimes limited data is discussed. The paper also shows how to use the flammability diagram with plant operations involving inerting and purging, and from bringing vessels into and out of service. A compilation of flammability diagrams for 30 materials, based on previously published data is provided.

An automated apparatus for acquiring data for a flammability diagram is described. The apparatus consists of a 20‐L sphere with an automated gas mixing system, a fuse‐wire ignition system, and a high speed pressure measurement and data acquisition system. Data derived from the apparatus includes flammability limits, maximum pressure during combustion, and the maximum pressure rate. The effect of fuse‐wire ignitor dynamics on the results is studied. A flammability diagram for methane drawn from data obtained from the apparatus, is presented.
The reactive system screening tool (RSST): An easy, inexpensive approach to the DIERS procedure
Authors: Fauske Hans K.
Published: June 2004

The RSST DIERS vent sizing methodology is revised to provide realistic design equations for reactive systems consistent with available large‐scale experience. Using easy to obtain RSST data such as rate of temperature rise and rate of pressure rise excellent agreement is illustrated for hybrid, vapor and gassy reactive systems.
Peroxide drum explosion and fire
Authors: Antrim Robert F. , Bender Michael T. , Clark Michael B. , Evers Lee , Hendershot Dennis C. , Magee Joseph W. , McGregor Jane M. , Morton Paul C. , Nelson John G. , Zeszotarski Carol Q.
Published: June 2004

A fifty‐five gallon steel drum of a liquid organic peroxide pressurized and ruptured in the mix room of a manufacturing plant. The head of the drum blew off and the ejected material ignited. The resulting fire was extinguished by the building sprinkler system and operating personnel. Although there were no injuries, the fire caused significant damage in the mix room. The investigation of this incident, its likely cause, and the corrective actions will be discussed.
Making RMP hazard assessment meaningful
Authors: Murphy John F. , Zimmermann Keith A.
Published: June 2004

The Brazoria County Petrochemical Council, 13 companies that are working together to enhance relations between industry and the community, united in a joint effort at complying with the EPA's Risk Management Program. One of the significant issues the group had to address was the need to develop meaningful hazard assessment for presentation to the public. The EPA's “Table Look‐Up Approach” found in the Offsite Consequence Analysis Guidance document is certainly a good tool; however, the built‐in conservatism results in over‐estimates of potential hazard areas. Much more meaningful results are shown to be obtained using one of the hazard release models.

The value of using a credible scenario with realistic meteorological data is demonstrated through the consistently smaller areas predicted by the PHAST Model for planning purposes. Realistic scenarios/failure modes and realistic model parameters are important so that the risk to the public is not overstated. Proprietary models such as PHAST are invaluable in providing more meaningful consequences for planning purposes.
The effects of valve wheel size, operation position and in‐line pressures on required torque for gate valves
Authors: Parks Sean C. , Schulze Lawrence J. H.
Published: June 2004

Some of the hazards encountered by process plant operators involve the operation of in‐line valves to control, start, and to stop flow. Torque required to operate valves may vary according to valve wheel size, in‐line pressure, and valve flange position (open/closed). This study determined how valve wheel size, in‐line pressure and valve position (open/closed) affect torque required to actuate a valve. Data were gathered with each combination of size, pressure and position for 336 valves in an operating petrochemical process facility. The results indicate that the main effects of valve wheel size, the in‐line pressure, and open/closed valve position significantly affect operational torque requirements. In addition, the interaction between position and pressure was significant for operational torque. The implication of these results is that operators are exposed to operational torque requirements that exceed maximum acceptable capabilities that have been determined in previous studies.
The prevention of major leaks—better inspection after construction?
Authors: Kletz Trevor A.
Published: June 2004

“On the 26th September (1850) we were able to fix the first column in its place. From this time I took the general management of the building under my charge, and spent my time on the works–feeling that, unless the same person who made the drawings was always present to assign each part to its proper place in the structure, it would have been impossible to finish the building in time for the opening on the 1st of May.”

Charles Fox, builder of the Crystal Palace, quoted by L. T. C. Rolt in “Victorian Engineering,” Penguin Books, 1970, p. 153.
Damage at syngas turbine by excessive steam superheating
Authors: Rall Wolfgang , Fromm Dieter
Published: June 2004

Problems with plant controls caused lower steam flow through the superheater coils and the fringe of a higher Btu gas.
Firebox explosion in a primary reformer furnace
Authors: Sparrow R. E.
Published: June 2004

Analysis of the incident with some practical considerations for reducing the risk.
Design and sizing of knock‐out drums/catchtanks for reactor emergency relief systems
Authors: Grossel Stanley S.
Published: June 2004

Sizing criteria and design procedures for knock‐out drums and catch tanks used in reactor emergency relief systems.
Thermal runaways: Problems with agitation
Authors: Weir E. D. , Gravenstine G. W. , Hoppe T. F.
Published: June 2004

Heat flow calorimetry‐an analytical technique to identify agitation hazards.
High temperature polymeric fire barriers
Authors: Jacobsen C. T.
Published: June 2004

The use of polymers is extensive both in electrical and construction systems. With regard to fire performance their high contribution to the heat load is a serious limitation to more extended use.
Mitigation of vapor cloud hazards
Authors: Prugh Richard W.
Published: June 2004

Part II. Limiting The Quantity Released and Countermeasures for Releases.
Emergency relief vent sizing for fire emergencies involving liquid‐filled atmospheric storage vessels
Authors: Fauske Hans K. , Epstein Michael , Grolmes Michael A. , Leung Joseph C.
Published: June 2004

For large atmospheric vessels the potential occurrence of sufficient liquid swell resulting in two‐phase flow is of special importance. Based upon an extension of analytical work it would appear justifiable to ignore two‐phase flow effects for non‐foamy systems.
Thermal stability of ethylene at elevated pressures
Authors: Britton Laurence G. , Taylor D. Alex , Wobser Donald C.
Published: June 2004

The initiation causes of ethylene decomposition are discussed and models presented to help anticipate and prevent decomposition. Thermal runaway, catalysis, influence of gas contaminants, adsorption heating, compression ignition and direct ignition are addressed. The effects of decomposition are described in terms of pressure and propagation.
Vibration monitoring—a programmed approach
Authors: Goggin David G.
Published: June 2004

Experience indicates that machinery vibration monitoring programs are most effective when planned in accordance with carefully established program goals and objectives. Methods are presented to determine the appropriate monitoring program for a given plant, key issues to address in program planning, and proven techniques for successfully implementing the program.
Anhydrous ammonia explosion in an ice cream plant
Authors: McRae Max H.
Published: June 2004

Causes and consequences of the explosion where firefighters and an employee barely escaped death or serious injury in December 1983.
The effects of system dynamics on failure: Illustrative examples
Authors: Brown Samuel J.
Published: June 2004

Several failure cases, the effects of dynamics of impulse and impact in concert with system support on failure.
A simple technique for the optimization of lay‐out and location for chemical plant safety
Authors: Nolan P. F. , Bradley C. W. J.
Published: June 2004

A computer program to optimize the use of land and ensure safe operation of plant. A logical process flow is maintained, while the position of plant items is optimized using a hill‐climbing technique.

A number of quantitative techniques exist for the measurement of hazard values for comparison of process routes in chemical plant design and operation. Such numerical values can also be used as a basis in lay‐out considerations. There is a need for a simple technique, which allows for the optimization of separation distances between plant by determining the minimum requirement for safe operation. This requirement determines the cost of land and that of piping and control lines. It is then possible to carry out economic comparisons between using separation distances and the installation of mobile and fixed prevention and protection systems. An optimization technique based on a modified hill‐climbing method is described.
Guidelines for hazard evaluation procedures: Preparation and content
Authors: Goldthwaite W. H. , Baybutt P. , Leverenz F. L. , Kemp Harold S.
Published: June 2004

Putting together the first publication of the Center for Chemical Process Safety.
Health, safety and loss control topics in the senior design courses
Authors: Kauffman David
Published: June 2004

The undergraduate chemical engineering curriculum at most U.S. colleges and universities is already very tightly structured, largely to meet accreditation criteria while still providing broad‐based education for the future. Health, safety and loss control issues were added to the program at the University of New Mexico through the use of weekly mini‐lectures in the senior design courses. Mini‐lectures, each ten to fifteen minutes, cover such topics as fires, explosions, the Bhopal incident, the Dow‐Mond index, fault‐tree analysis, HAZOP analysis, etc.
Laboratory techniques for the quantitative study of thermal decompositions
Authors: Cronin John L. , Nolan Philip F.
Published: June 2004

Two experimental methods are described for studying thermal decomposition reactions in solids and liquids.

The first allows early detection of initial exothermicity, calculation of pseudo kinetic parameters describing subsequent decomposition, and estimation of scale effects on the initial temperature for self‐sustaining reaction.

The second method yields additional data which provides a basis for relief system design.
Ammonia synthesis enhancement through heat‐mass‐exchange
Authors: Lavie Ram
Published: June 2004

The HME Ammonia Synthesis Enhancement is a simple process modification enhancing synthesis productivity by reducing energy consumption and/or increasing plant capacity as compared to conventional alternatives. In this paper, it is presented as an attractive alternative to low temperature ammonia separation in low pressure plants.

Some HME performance sensitivities and their implications on the design of a unit are studied. Typical HME enhancement economics is summarized in comparison with a typical conventional alternative. This indicates a potential 25% reduction in refrigeration power consumption, paying out the HME unit in a relatively short time. The application of the HME enhancement is expected to promote synthesis at lower pressures.
Functional requirements and design criteria for the design of high hazard containment laboratories
Authors: Hoyle E. Robinson , Stricoff R. Scott
Published: June 2004

A brief overview of the design process which has been successfully utilized in planning a high hazard containment laboratory.
Understanding cooling towers: The route to energy savings
Authors: Smith Matt
Published: June 2004

Why do we use cooling towers? The answer is simple. Cooling towers allow us to efficiently reject heat to the atmosphere at a lower temperature than other available processes. The key words in that last sentence are “at a lower temperature”.
Inhibitor‐oxygen interactions in acrylic acid stabilization
Authors: Levy Leon B.
Published: June 2004

Polymerization inhibitors are used in the processing and storage of acrylic acid. Depending upon the inhibitor and the conditions, it is sometimes imperative that oxygen be present for inhibitor “activation.”
Increasing efficiency in direct contact heat transfer
Authors: Strigle Ralph F. , Nakano Tsuneo
Published: June 2004

Revamping the top section of the water quench tower in an olefins plant provided a 74% reduction in pressure drop. First stage compression ratio was reduced from 2.21 to 2.02. An additional modification of the lower section of such a column with tower packing reduced the heat rejected to the cooling water by 35% with no increase in pressure drop.
Static hazards of drum filling. II. Electrostatic models: Theory and experiment
Authors: Britton Laurence G. , Smith Jack A.
Published: June 2004

For drum filling, a demarcation of 50 pS/m (below which a liquid may accumulate hazardous static in a grounded drum) is conservative and takes account of the effects of temperature and/or charge density on relaxation rate. The worst‐case conductivity as regards static accumulation rate is about 0.5 pS/m, but in practice this should not correspond to the worst‐case charge generation rate. Published forms of the Schon equation are not conservative for smooth‐bore pipes and hoses; a new equation is proposed. Certain rough‐bore hoses containing an inner grounding spiral can generate almost as much charge as a microfilter. Theory and experiment are discussed with reference to published Codes and Guidelines; attention is given to filter placement and drum linings.
Causes of ammonia plant shutdowns survey V
Authors: Williams Gerald P. , Hoehing William W. , Byington Robert G.
Published: June 2004

The onstream factor for large tonnage ammonia plants has plummeted to 80.8 percent as inventory control and feedstock curtailment cause almost fifty percent of total downtime.
Sizing excess flow valves
Authors: Freeman R. A. , Shaw D. A.
Published: June 2004

To prevent the catastrophic release of LPG into the atmosphere, The National Fire Protection Association recommends the installation of safety devices such as reverse flow check valves and excess flow valves [1].
CIL's experience with a computerized ammonia plant trip system
Authors: Cobb A. J. , Monier‐Williams S.
Published: June 2004

The computerized trip system has been in use since August, 1985, at the CIL Ammonia II plant. Superior reliability, essential avoiding unnecessary shutdowns, while protecting the plant from accident, is obtained through use of a fault‐tolerant configuration.
Good safety procedures can prevent accidents: Some examples
Authors: Kletz Trevor A.
Published: June 2004

Good operating and safety procedures can reduce the demand rate on a protective system.
The current state of the art in optical fire detection
Authors: Cholin John
Published: June 2004

There are few, if any, facets of modern life that have not been touched in some way by the technological revolution in electronics. Each year the technology advances further, making possible those things which were deemed unattainable just a few short years ago. In some cases the advances are the result of a step‐wise evolution of a product while in others revolutions in design concept yield quantum leaps in performance.
Determining spacing by radiant heat limits
Authors: Martinsen W. E. , Johnson D. W. , Millsap S. B.
Published: June 2004

A method for calculating the “safe” separation distance between pressurized LPG storage tanks and flammable liquid storage tank dikes is presented. The safe separation distance is defined as the minimum distance at which the radiant heat from a dike fire is insufficient to cause catastrophic tank failure, even if no cooling water is applied to the LPG tank.
Control structure for batch reactor control
Authors: Craig L. W.
Published: June 2004

A hierarchical structure which allows maximum use of commercially available microprocessor equipment while allowing additional functionality to be implemented as needed.
Design charts for two‐phase flashing flow in emergency pressure relief systems
Authors: First K. E. , Huff J. E.
Published: June 2004

The design charts of this paper apply to the high velocity flow of a boiling liquid and its vapor during two‐phase emergency pressure relief events. These charts are used to size relief system components to handle a given minimum relief flow requirement. This flow requirement is determined by computer simulation programs such as that described in [1], or by special‐case models [2, 3, 4]. Though intended for use in sizing pressure relief systems, the charts are applicable to high‐velocity flashing flow problems.
Training technology through interaction management
Authors: Latino Nick
Published: June 2004

A discussion of specialized computer training to enable employees achieve a higher degree of learner proficiency that will lead to the absence of process errors.
Building a high‐integrity ammonia storage tank—1988
Authors: Thompson James R. , Carnegie Richard N.
Published: June 2004

In late 1984, initial work began on preparing a project to install atmospheric ammonia storage at DuPont's Victoria, Texas plant. This storage was to supplement the existing ammonia spheres. In the aftermath of Bhopal and, in light of DuPont's response to that incident, the project focus was changed to one of replacing all pressurized ammonia storage and rail car unloading at the site and installing atmospheric ammonia storage of the highest possible integrity.

This paper discusses the various phases of the project and the high‐integrity design of the storage facilities.