bluuebunny/crossref_metadata_2025_split huggingface dataset:
Surface grafting onto SiC nanoparticles with glycidyl methacrylate in emulsion
Authors: Luo Ying , Rong Min Zhi , Zhang Ming Qiu , Friedrich Klaus 
Published: June 2004

AbstractTo improve the tribological performance of nano‐SiC particles filled epoxy composites, surface modification of the fillers is necessary. By means of soapless emulsion polymerization method, graft polymerization of glycidyl methacrylate (GMA) onto the surface of alkyl nano‐SiC was carried out, resulting in composite particles with SiC core and polymeric shell in which polyglycidyl methacrylate (PGMA) is chemically attached to the nanoparticles by the double bonds introduced during the pretreatment with a coupling agent. By analyzing the reaction mechanism, the emulsion polymerization loci were found to be situated at the SiC surface. Also, the factors affecting the grafting yielding of PGMA on the particles were investigated, including monomer concentration, initiator consumption, reaction temperature, reaction time, etc. Accordingly, an optimum grafting reaction condition was determined. It was shown that the grafted nanoparticles exhibit greatly improved dispersibility in good solvent for the grafting polymer. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 3842–3852, 2004
Venting of gaseous explosions
Authors: Mercx W. P. M. , van Wingerden C. J. M. , Pasman H. J. 
Published: June 2004

AbstractAn experimental investigation has been performed into the venting of methane‐air explosions in heating plants. The investigation was performed on a realistic scale in a 38.5 m3 enclosure. The first part of the experimental program concerns the influence of the “usual” parameters such as the vent opening area, the vent opening pressure, the ignition location and the vent opening configuration. The second part of the investigation concerns the influence of factors related to heating plants. Thus the effect of introducing a large obstacle, that is the central heating apparatus, and the effect of venting through a dormer window (heating plants are often located in the cellar of a building allowing explosion venting via a dormer window only) are investigated.
The effect of oxygen on vinyl acetate and acrylic monomer stabilization
Authors: Levy Leon B. 
Published: June 2004

AbstractVinyl acetate monomer and acrylic acid and its esters are stabilized with phenolic polymerization inhibitors. Oxygen is needed for these stabilizers to work effectively in acrylic monomers, but is not necessary for vinyl acetate monomer, and actually destabilizes it at elevated temperatures.
Data summary of the national fire protection association's BLEVE tests
Authors: Melhem G. A. , Croce P. A. , Abraham H. 
Published: June 2004

AbstractIn conjunction with the production of a new film entitled BLEVE Update®2, the National Fire Protection Association (NFPA) sponsored a series of six Boiling Liquid Expanding Vapor Explosion (BLEVE) tests using 1.893 m3 propane tanks. The purpose of the experiments was to obtain film footage of BLEVEs and to compile test data and documentation that might help to better define failure mechanisms and other important physical processes involved. The experiments included tests with simulated pool fires and tests with liquid and gaseous flame jets. The fill level of each tank was varied for the six experiments. The tanks were instrumented with thermocouples and pressure transducers in both the liquid and vapor space. This paper describes the test setup and summarizes the data measurements obtained.
The determination of compatibility via thermal analysis and mathematical modeling
Authors: Hofelich T. C. , Frurip D. J. , Powers J. B. 
Published: June 2004

AbstractNew regulations in 1991 (HM‐183) have required that materials may not be coshipped in the same cargo tank motor vehicle if, as a result of their mixing “…an unsafe condition would occur, such as an explosion, fire, excessive increase of pressure or heat or the release of toxic vapors.”In order to determine the potential hazards resulting from inadvertent mixing which would result in a hazardous condition, a technically sound evaluation procedure was needed which was reasonably accurate as well as time and cost effective. This required both thermodynamic (heat and/or pressure released) and kinetic parameters (is the energy released immediately or does it take a day, week, month etc.?). A model has been developed using the SimuSolvA Trademark of the Dow Chemical Co.
computer program and Microsoft's EXCEL™ spreadsheet which combines the kinetics and thermodynamics for a reaction with the heat transfer parameters for a given tanker truck. Real heat loss data were then obtained for a typical compartmentalized tanker truck for use in the model. The rates and enthalpies for reaction input can be taken from ARC, DSC, or literature data. Since a very large number of binary combinations of potentiai mixtures are possible, materials were grouped according to chemical functionality. A model compound was chosen to represent each functional group. These materials were chosen to best represent the worst‐case reactivity of the group, unimpeded by steric or other factors. A single material/formulation could be classified into more than one grouping. Representative data were complied from experimental studies (Mixing calorimetry, ARC, DSC, etc.) and a wide variety of internal and external literature sources. Where outside sources described a potential incompatibility between groups, the data were gathered on model compounds and input into the model to determine pertinent compatibility. A compatibility chart was constructed for the resulting potential binary mixtures based upon these results.
Simulating flammability under process conditions
Authors: O'Shaughnessey Dan , Powers Bruce 
Published: June 2004

AbstractEstablishing safe operating parameters requires the determination of flammability characteristics under a myriad of process conditions. In order to meet these needs, a combined approach of literature search, calculational modeling, and experimental simulation is often utilized. A few specific projects will be reviewed as example methods for evaluating flammability properties under challenging environments. Flammability diagrams and system configuration figures are presented for further review while the interesting discoveries of each project are covered for interpretation and application to process conditions.
Hazard evaluation of polymerizable compounds
Authors: Frurip D. J. , Chakrabarti A. , Hofelich T. C. , Martinez S. J. , Whiting L. F. 
Published: June 2004

AbstractReactive monomers are a special class of materials used widely in the chemical industry in the production of polymers. Many of these materials are thermally unstable and may polymerize during handling and storage with a release of significant amounts of energy. If this energy is not controlled properly, it can lead to a runaway reaction. Compounding the concern for the stability of monomers is the fact that these materials are typically transported and stored in large volume. The undesired initiation of the polymerization reaction may be caused by a number of factors, including contamination, exposure to extreme environmental conditions, or inhibitor loss. For example, an “unintended” polymerization can result from a seemingly benign procedure such as spill control with common absorbents. These and other factors mean that the reactive chemicals evaluation of monomers presents special problems and concerns which require more detailed experimental design for reliable hazard testing. This paper discusses the practical aspects of reactive chemicals testing strategies for monomers and rules‐of‐thumb for monomer inhibition, compatibility, spill control, and so‐called quenching (also called short‐stopping) agents. The techniques discussed range from simple “age and observe” type tests to more sophisticated heat flux calorimetry evaluations. We also discuss the more routine application of Differential Scanning Calorimetry and Accelerating Rate Calorimetry to monomers. Vent sizing applications with the VSP device are also presented with emphasis on total containment during a runaway.
Detonation flame arrester qualifying application parameter for explosion prevention in vapor handling systems
Authors: Lapp Ken , Werneburg Hal 
Published: June 2004

AbstractCompliance with air quality initiatives often involves the installation of a vapor collection system (VCS). The purpose of a VCS is to collect and direct vapors to a flare, incinerator or recovery unit. This practice creates a hazardous situation wherein an explosive vapor is tied into an ignition source.This paper examines nine factors in creating the most severe flame front possible in a practical, full sized piping system. They are: gas types, gas mixtures, pre‐ignition pressure, temperature of the ignition energy, temperature of the mixture, ignition location, pipe configuration, protected side restrictions and endurance to stabilized flame. The paper also examines which of these factors are in the jurisdiction of the plant process and those factors for which proof of capability have been demonstrated by commercially manufactured detonation flame arresters in actual tests.Many certification standards define the acceptance testing of DFA's. They have been evolving and improving over the past two decades. A summary is made of which flame propagation parameters are addressed by various standards.When reviewed in this context, and applied to practical operating conditions, new levels of confidence and safety are created. The critical variables within the control of the industry are outlined. This information can be applied to reduce the current high frequency of vapor transportation explosions.
Dow's chemical exposure index guide
Authors: Marshall John T. , Mundt Art 
Published: June 2004

AbstractA number of events in the 1970's and 1980's impacted the course of process safety. Incidents such as Flixborough, Seveso, Three‐Mile Island, and Bhopal are well known throughout industry and are recognized as examples of major disasters. Even though events leading up to these disasters were completely different they had one common element between them: a substance was released from a manufacturing unit, became airborne and presented a hazard of such magnitude as to place the safety of both employees and the surrounding public in jeopardy. As a result, industry became increasingly concerned regarding potential loss, in human and economic terms, as plants and equipment grew in size [1]. The Flixborough incident raised the level of concern for process safety, particularly in terms of the hazards presented by fire and explosion. Seveso and Three‐Mile Island emphasized the need to consider far‐field exposure. The Bhopal incident created an urgent need to recognize and understand the expected downwind impact of potential releases of acutely toxic substances to the air. In order to meet this need, the Dow Chemical Company, a recognized leader in the area of safety and loss prevention, presented a Chemical Exposure Index in 1986. AIChE has recently published an updated version entitled Dow's Chemical Exposure Index Guide (first edition).The above publication appears as an AIChE Technical Manual entitled Dow's Chemical Exposure Index Guide [ISBN 0‐8169‐0647‐5] and is available through the AIChE Customer Service Department, 345 East 47th St., New York, N.Y. 10017. Telephone: 1‐800‐242‐4363.
Protection of storage tanks from two‐phase flow due to fire exposure
Authors: Fisher Harold G. , Forrest Harry S. 
Published: June 2004

AbstractVarious approaches are presented to protect storage tanks from fire exposure. Design techniques for emergency relief devices flowing vapor or two‐phase vapor‐liquid flow are discussed. The effects of maximum design pressure versus emergency relief device set pressure, fire exposure insulation and water spray protection, fire exposure duration, relief device flow characterization and inlet pipe pressure drop and discharge pipe back pressure must all be considered when designing to protect storage tanks.This paper discusses some aspects of pressure relief design for low pressure storage tanks. The concepts and techniques discussed here can be modified to include design guidance/recommended design parameters from specific standards. Even if not used for pressure relief design, the concepts/calculations presented should be useful for Process Hazard Analysis studies to determine the relative ranking of credible scenarios.The reader is cautioned that no attempt was made to cover every design situation or conform to any design standard/recommended practice. There are too many specific scenarios and too many (unnecessary) conflicts between standards/recommended practices. Instead, the reader is cautioned to ensure that all prescribed federal, state and local as well as company design standards are followed when mandated.
The anticipated impact of the EPA's RMP regulation on the ammonia industry
Authors: Auger John E. 
Published: June 2004

AbstractOver three years ago the Occupational Safety and Health Act (OSHA) process safety management regulation became effective in the United States. Most of us have dealt with the initial shock of that regulation and what it entailed and, hopefully, we have things pretty much under control.Although, one hates to be the bearer of bad news, it is not yet time to relax. The Environmental Protection Agency (EPA) has another process safety regulation in store for the ammonia industry. In fact, in some areas, the EPA's upcoming risk management programs regulation makes the OSHA regulation look like child's play.It is much better to be proactive than reactive when responding to new regulations. A proactive approach allows one to make the correct long‐term decisions without the pressure of a compliance deadline.
Choosing the level of detail for hazard identification
Authors: Deshotels Robert , Dejmek Mark 
Published: June 2004

AbstractTo be cost‐effective, a process hazards analysis effort should concentrate on those areas where there is the greatest potential for risk reduction. The level of detail of the analysis is a factor which affects the magnitude of effort and the completeness of the results. Often, there is an opportunity to combine components together to be analyzed as a single entity, in order to increase the efficiency of the hazard identification process. Issues arise concerning how to combine components, and what should be the appropriate level of detail for consideration. For instance, a level of detail shown on piping and instrumentation diagrams which has proven convenient for process design may not be sufficient or optimal for hazard identification. To resolve such issues, some guidelines are proposed for determining the appropriate level of detail. These guidelines have been deduced from the intent of the analysis and the basic assumptions of the methodology.
PSM's most common struggle: Implementing mechanical integrity
Authors: Remson Andrew C. , Farmer Jill H. , King C. Stephen 
Published: June 2004

AbstractMost companies have found that of the 14 OSHA PSM elements, Mechanical Integrity (MI) presents the greatest implementation challenge. Although maintenance departments have successfully installed, repaired, and replaced plant equipment for decades, many of these same maintenance departments have struggled with OSHA's PSM requirements. One major challenge is prioritizing resources. Opportunities to improve will always exist; however, it is often difficult to effectively allocate money and manpower. Another challenge is simply getting organized. The MI program should be supported by appropriate, useful procedures; but given the multifaceted and ever‐changing nature of maintenance, what procedures should be written? How detailed should the procedures be? With nearly 3 years of PSM enforcement complete, an analysis of OSHA's MI citations helps to provide insight to these challenges. This paper presents ideas for implementing MI in a manner that meets OSHA's expectations while contributing to safe, effective maintenance in PSM‐covered processes. In particular, the paper presents ideas for developing MI programs that effectively prioritize company resources, with appropriate inspection/test/preventive maintenance and quality assurance (QA) activities. This paper also presents ideas for developing a list of mechanical integrity procedures to address OSHA's requirements as well as the type of information to include in those procedures.
Utility and energy cost containment
Authors: Newhouse Roland 
Published: June 2004

AbstractOne of the most lucrative areas for improving bottom line profitability is related to an organization's costs for utilities and energy. Such thing as gas, electric, water, and telephones are treasure chests of cost reduction opportunities. In the past, these items have been viewed as a fixed expense or basic mundane commodity. In recent years, these items have become a large portion of product cost now must be examined on a contiual basis. A formal income improvement program to capture and report on the savings is a requirement for remaining competitive in a global economy.
Critical elements in the design of piping systems for toxic fluids
Authors: Getz R. C. 
Published: June 2004

AbstractWhile releases of hazardous/toxic fluids from pressurized pipelines are infrequent, the potential for a catastrophic event resulting from such a release warrants extraordinary care of the hazardous/toxic piping systems containing these fluids, during the entire plant life cycle.System identification, segregation, material and component selection, construction techniques, and preventative maintenance programs all contribute to improved system reliability, and are discussed herein. Methods to mitigate damages in the event of a failure are also discussed.
A comparative examination of the fire performance of pipe insulation
Authors: Babrauskas Vytenis 
Published: June 2004

AbstractA standard method for evaluating the fire performance of pipe insulation is not available in North America. In Europe, however, the regional standards organization NORDTEST has had available for several years now a method specifically designed for this purpose. The NORDTEST NT FIRE 036 test is a full‐scale room fire test where the pipe insulation is installed along the ceiling and subjected to a gas burner fire. Four classes of performance (Class I through III, plus unrated) are used to evaluate the products. In the present work, 4, different pipe insulation products, representing the most common materials used for this purpose, have been examined according to this test. The results showed that rock wool insulation gave the best fire performance, with phenolic foam being in the least safe rated category. Synthetic foam rubber and polyethylene insulation products gave intermediate performance.
Flame propagation in pipes of pneumatic conveying systems and exhaust equipment
Authors: Vogl Albrecht 
Published: June 2004

AbstractThe dust explosion course in pipes of pneumatic conveying systems is discussed. A high number of large scale tests was carried out and the influence of pipe diameter, dust concentration, conveying velocity, location of the ignition source and powder specific parameters was taken into account. The concentration of the ignited dust/air mixture is measured and controlled by an opto‐electronic measuring system. The flame propagation time, the flame front velocity and the explosion pressure depending on the distance of the flame front from the ignition source are shown as well as the explosion pressure as a function of the flame front velocity. The experimental results give important hints concerning the explosion course in pipes, the strength of pipes and location of disengagement systems under practical operating conditions.
Explosion protection of pipe systems conveying combustible dusts or flammable gases
Authors: Senecal Joseph A. , Garzia Henry W. 
Published: June 2004

AbstractA complete solution to explosion protection in facilities processing combustible dusts or flammable gases often involves consideration of dust and gas conveying systems as well as primary process volumes. The pipes or ducts of the conveying system can serve as efficient means of propagating deflagrations from point to point in a plant. Subsequent to the implementation of the requirements of the Clean Air Act Amendments of 1990 the need for explosion protection systems on pipes and ducts has increased. VOCs and vapors of hazardous chemicals are commonly incinerated. Such systems are subject to flash back failure and ignition of flammable gases in the feed pipe. Feed bins and product collectors up and down stream are at risk of ignition from sparks generated at grinding stations. Systems feeding dusty solids to furnaces are subject to flash back. This paper summarizes present day methods of detecting pipeline deflagration events and intercepting same using either fast closing valves or chemical barrier systems. Modes of deflagration detection, type and placement of barriers are discussed. The impact of the phase out of the production of halons in this area is also discussed. Examples of combustible dust and flammable gas protection systems are described.
Pressure relief with highly viscous fluids
Authors: Fründt Jens , Steiff Artur , Weinspach Paul‐Michael 
Published: June 2004

AbstractThe required vent area for pressure relief equipment is affected by the gas/vapor‐liquid disengagement. The main objective of this work is the experimental verification of disengagement models for highly viscous fluids. The dynamic two‐phase flow in the vessel is modeled with a one dimensional finite volume approach, the phase slip is taken into account with a drift flux model recommended by DIERS. The simulation shows good agreement with the experiment if the drift velocity is considered as a function of the fluid phase viscosity.
Viscosity correction factor for safety relief valves
Authors: Darby Ron , Molavi Kamyar 
Published: June 2004

AbstractA commercial computation fluid dynamics (CFD) code was used to compute the discharge coefficient for a representative relief valve configuration and various nozzle sizes, for Newtonian liquids with various viscosities. The results are compared with values of the viscosity correction factor, Kv, from the API Recommended Practice 520, and equations are proposed to represent both the Kv curve and the computational results in a correspondings form, which also includes the effect of the dimensionless nozzle diameter on the valve Kv.
Advancing inherent safety into methodology
Authors: Lutz William K. 
Published: June 2004

AbstractCompetition in commodity centered chemicals, in the Chemical Process Industry (CPI), has led many chemical companies to consider cost reduction in every facet of their businesses. Once the obvious fixed cost control measures are achieved, the invention, development, and commercialization of new and existing products is questioned for cost reduction opportunities. The challenge is to bring the product line to market with sufficient volume and quality at a lower cost than any competitors. Short term and long term profitability, per capita of the corporation, must continue upward or at least break‐even in the low end of the chemical business cycle. Consideration of the principles of chemistry and physics early in the development and throughout the life of a chemical product can eliminate the need for instrumentation or administrative controls that add significant cost to the product over its lifetime. This paper examines opportunities to use inherent safety principles to improve lifetime cost, while reducing or eliminating hazards.