ISSN:1066-8527    

DOI:10.1002/prs.680160302

出版商:American Institute of Chemical Engineers    

年代:1997

数据来源: WILEY

摘要:

AbstractThe National Fire Protection Association (NFPA) has developed a system for labeling short‐term acute hazards of materials in fire, or emergency situations [1]. The procedures for obtaining the hazard rating for health and flammability are based upon measured quantities [2], but the basis for assigning reactivity ratings are largely qualitative [1]. This paper proposes a quantitative approach for assigning reactivity hazard rating

ISSN:1066-8527    

DOI:10.1002/prs.680160303

出版商:American Institute of Chemical Engineers    

年代:1997

数据来源: WILEY

摘要:

AbstractHuman supervisory control and monitoring of automated systems, as well as, passive system(s) information processing can all be classified as forms of out‐of‐the‐loop (OOTL) performance. Whether the operator's task is to decide if process control intervention is necessary, detect a critical system event, or accept or reject the actions of a computer controller, he or she is removed from direct, real‐time control of the system. OOTL performance is a critical issue in overall automated systems functioning because it is associated with numerous negative consequences including: (a) operator failure to observe system parameter changes and intervene when necessary (vigilance decrements); (b) human over‐trust in computer controllers (complacency); (c) operator loss of system or situation awareness; and (d) operator direct/manual control skill decay. These consequences have been found to impact human performance under both normal operating conditions and system failure modes, with a greater effect on the latter [15] leading to serious problems in operator ability to perform their assigned tasks when working with automated systems.Level of automation (LOA) has been put forth as an approach to ameliorating OOTL performance problems. It is intended to determine the optimal assignment of control between a human operator and computer in order to keep both involved in system operations. LOA considers the capabilities and capacities of both the human and computer controller in determining their optimal coupling. It constitutes a systems approach to resolving OOTL performance problems by minimizing the negative consequences associated with the removal of the operator from active system control, and allows for the strengths of both human decision making and computer processing to be realized. When compared to a technological approach that assesses only the capabilities of the computer in allocating as much responsibility to the machine as possible, and assigning the remaining tasks to the human operator, the advantages can be considerable.A LOA taxonomy will be presented along with research examining its utility in a dynamic control task. Using LOA to identify optimal combinations of human and computer control was found to produce improvements in system performance under intermediate levels. These levels involve joint human and computer control of various system functions, such as monitoring, planning, and option selection and implementation. Results indicated decreases in the number of system processes/tasks overlooked by operators. These improvements may translate into cost reductions due to improved operational safety and are anticipated to be applicable to process control o

ISSN:1066-8527    

DOI:10.1002/prs.680160304

出版商:American Institute of Chemical Engineers    

年代:1997

数据来源: WILEY

摘要:

AbstractIn the course of chemical process and plant design, engineers identify potential hazardous incidents. These potential incidents may be identified through special hazard analysis reviews and procedures, or by the design team in the course of design activities. To manage and control those hazards, the team will modify the initial design, often by adding on additional protective devices and systems—alarms, interlocks or active protective systems. However, any change in a system, even a change intended to prevent or mitigate a potential hazardous incident, also has the potential to introduce new hazards, or new mechanisms by which existing hazards can result in an incident. A number of case studies illustrating this point are reviewed. The examples illustrate the importance of a management of change program, which must consider all changes including the addition of safety devices and systems, and which must throughly consider all potential effects on the syste

ISSN:1066-8527    

DOI:10.1002/prs.680160305

出版商:American Institute of Chemical Engineers    

年代:1997

数据来源: WILEY

摘要:

AbstractThe organization of a menu can significantly affect user response time when selecting targets from that menu. Previous empirical studies have used laboratory tests to suggest menu design rules that can optimize user response. This study applied the design rules to a menu used for display selection on an Energy Management System. In such a study, the total number of menu targets and the relationships among them is not variable, so some compromises must be made when applying the rules. This study produced a new menu that had measurable improvement in user response time over the existing menu. Design rules regarding grouping of targets and methods of organization were successfully applied during the menu redesign.

ISSN:1066-8527    

DOI:10.1002/prs.680160306

出版商:American Institute of Chemical Engineers    

年代:1997

数据来源: WILEY

摘要:

AbstractAdvanced methods for the design of emergency relief systems were developed under the auspices of the AIChE Design Institute for Emergency Relief Systems (DIERS). Rapid progress has continued, but most testing has been done at laboratory or small pilot plant scale. Full scale tests of design methods for emergency relief systems are much needed, but would be prohibitively expensive.Proposed here is a practical alternative: Use existing production data from operating plants to test design methods for emergency relief systems. Fortunately, although most emergency pressure relief events represent plant upsets and lost production, the relief system prevents a catastrophe in most process upsets. However, the qualitatively successful operation of an emergency relief system in a given upset does not represent proof of the design method employed. More importantly, it does not guarantee that the existing relief system will perform successfully in every credible upset that the process might experience in the future.Advocated here is an industry‐wide program to use data from selected process upsets to systematically evaluate the effectiveness of current emergency relief system design methods to quantitatively predict the performance of existing emergency relief systems. Products of this effort would include confirmation of a significant number of existing design methods, identification of deficiencies in current methods, and a published compendium of documented and evaluated case histories of full‐scale relief system performance. In addition to its instructive value to workers in emergency relief, the compendium could be used to test new design methods.This proposal is offered to the AIChE DIERS Users' Group. The DIERS Users' Group, which is comprised of over one hundred member companies, has representatives qualified to define, organize, sponsor, and execute a multi‐company research program of this type. (NOTE: At the semiannual meeting of the AIChE DIERS Users' Group in Calgary, Alberta, Canada on September 9, 1996, this proposal was presented to and adopted by the DIERS Users' Group and assigned to the Case Histories Commi

ISSN:1066-8527    

DOI:10.1002/prs.680160307

出版商:American Institute of Chemical Engineers    

年代:1997

数据来源: WILEY

摘要:

AbstractThe well‐known Yellow Book, nickname for the publication by the Dutch Ministry of Social Affairs and the Environment contains a number of models for prediction of the effects following an accidenial release of hazardous materials. TNO was involved in a complete revision of this Yellow Book. One of the models that has been completely revised is the blast prediction model for vapor cloud explosions. The Multy‐Energy model was selected as the new model to be incorporated in the revision. The concept of the Multy‐Energy model is widely accepted as a better alternative to TNT equivalence methods although a practical application is hampered by a lack of guidance for application in practice. Guidance for application is given in the revision, though it still leads to conservative solutions.This paper describes how the method should be applied according to the revised Yellow Book. The motivation for the guidance for application given is discussed by comparison with guidance given in other publications and with experimental results obtained from some large scale experimental programs. Present efforts in an ongoing research program by TNO to obtain more detailed and sound guidance is presented as

ISSN:1066-8527    

DOI:10.1002/prs.680160308

出版商:American Institute of Chemical Engineers    

年代:1997

数据来源: WILEY

摘要:

AbstractWhereas the management of change concept is a common practice for many production facilities, its application in a research and development environment is relatively new. How does one effectively manage a change control program when “change” is the normal way of doing business? Is it really necessary for pilot plants? These were the challenges facing the Searle chemical pilot plant organization in 1991 when it initiated its program.This paper describes the Searle pilot plant equipment management of change program, its evolution, and implementation. The problems and issues faced during implementation will also be revie

ISSN:1066-8527    

DOI:10.1002/prs.680160309

出版商:American Institute of Chemical Engineers    

年代:1997

数据来源: WILEY

摘要:

AbstractIn 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 t

ISSN:1066-8527    

DOI:10.1002/prs.680160310

出版商:American Institute of Chemical Engineers    

年代:1997

数据来源: WILEY

摘要:

AbstractThis 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.

ISSN:1066-8527    

DOI:10.1002/prs.680160311

出版商:American Institute of Chemical Engineers    

年代:1997

数据来源: WILEY