Design and sizing of knock-out drums/catchtanks for reactor emergency relief systems

Sizing criteria and design procedures for knock-out drums and catch tanks used in reactor emergency relief systems.     

Design charts for two-phase flashing flow in emergency pressure relief systems

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.     

Application of the DIERS methodology to the study of runaway polymerization: Validation of the DIERS methodology using blow-down tests

The Design Institute for Emergency Relief Systems (DIERS) and more recently the DIERS Users Group have been investigating various aspects of emergency relief for more than 12 years. The DIERS programs have given rise to an in-depth understanding of the basic mechanism of how runaway thermal reactions are safely vented. In concert with the development of the understanding of the venting mechanism, DIERS also developed experimental procedures and computational techniques for estimating emergency vent sizes.     

Design of quench system for runaway reactions using bench-scale equipment

Runaway chemical reactions are a potential problem in many sectors of the chemical industry. The typical hazard scenario involves a batch (or semi-batch) chemical reaction where, due to an operator error or instrument failure, the reaction temperature begins to accelerate rapidly. The rise in temperature is, of course, accompanied by a rise in pressure and in order to prevent vessel rupture, some means of protection must be provided. The common approach to overpressure protection in the industry is to fit a relief device to the reactor vessel in question; the device opens at a predetermined pressure and, provided it is sized correctly, the maximum pressure can be kept within acceptable limits. The Design Institute for Emergency Relief Systems (DIERS), organized through the auspices of the AIChE [1], undertook several years of research to develop the methodology for the sizing of relief systems to cope with runaway reactions. The emphasis in industry has changed so considerably since the DIERS work that companies are interested in avoiding the release of chemicals to the environment in addition to preventing equipment damage. This adds considerable complexity to the relief system and must be evaluated with the same thoroughness as the vent design.     

The DIERS users group: A forum for development/dissemination of emergency relief system design technology

DIERS was formed in 1976 to develop methods for the design of emergency relief systems capable of handling runaway reactions [1, 2]. Of particular interest at the time were when tow-phase flow venting would occur and the applicability of different methods for sizing emergency relief systems for two-phase, vapor-liquid flashing flow. Approximately $1.6MM was devoted to investigations of two-phase, vapor-liquid onset/disengagement dynamics and the hydrodynamics of emergency relief systems.     

Emergency relief system design for reactive and non-reactive systems: Extension of the DIERS methodology

Simple mechanistic models for reactive and non-reactive chemicals are summarized. The DIERS methodology has been extended as well as simplified to account for vapor disengagement and frictional effects including laminar flow conditions—both principal objectives of the DIERS program.     

The patient trajectory: A modelling tool for planning rural telemedicine systems

The authors present an analytical tool developed and applied to plan for the use of telecommunications technology to link a non-physician health care provider in a rural satellite clinic to a central source of medical expertise. The principal result obtained is that narrowband technologies appear nearly two- thirds as effective as broadband technologies in averting patient travel.     

QRA of chemical reaction systems: The state of the practice

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.     

一起突发性地表水环境污染监测案例的分析与思考

针对发生在石家庄灵寿县境内的一起突发性地表水环境污染事件,介绍了石家庄市环境监测中心采取的现场勘查、监测、采样和处置等应急处理措施,就建立科学的应急监测管理机制提出建议:1)加强河流跨界交汇断面的监测;2)提高地表水生物监测技术水平;3)组建一支专业的污染事件应急监测队伍。     

理想气体反应不同标准态时热力学函数间关系式的补充

通过理想气体反应等温方程和标准态转换,给出了摩尔反应热力学能、摩尔反应焓、标准摩尔反应亥姆霍兹函数和标准摩尔反应吉布斯函数在等温、等客条件下使用不同标准态时的另一组转换关系式,加上已经给出的在等温、等压条件下使用不同标准态时几个热力学函数间的转换关系式,使这类关系式更全面、完整.对这些关系式的应用条件以及在热化学和基元...     

Assessing the technological capabilities of firms: developing a policy tool

The development of technological capabilities results from an extended learning process and external policy agents can play an important role in its development. This paper outlines trends in governmental and non-governmental policy initiatives and the use of concepts such as capability and absorptive capacity, which are positioned within generic-staged models of capability maturity. This paper describes the development of a technology capability assessment/audit tool that has been designed to help locate firms within four archetypes based upon their level of maturity on nine key dimensions of the management of technology. The tool is intended to help bridge the gap between our theoretical understanding of the principles of technology management and policy practice – allowing policy makers to design mechanisms that focus resources in areas of greatest need through the appropriate selection of policy mechanisms and the targeted design of policy. The use of this tool in field experiments is described along with the implications for policy making.     

Simple money-based tests for choosing between private and public delivery: a discussion of the issues

The decision when to provide services by the public sector and when to use the private sector is a fundamental one. The economic literature emphasises that the efficiency of the mechanisms of delivery will depend on the contractual nature of what can be achieved by the parties and the political economy forces. Totally separate from this literature, however, governments have tried to implement practical and simple tests to indicate when to use private and when to use public delivery methods. The aim of this paper is to address some of the issues associated with simple money-based tests.     

Threshold tests for the control of mergers: The Australian experience

Merger policy in Australia has been formulated for a small open economy. Tight merger control has been avoided in order not to impede rationalisation and improved international competitiveness. From 1977 to early 1993 a merger or acquisition was only prohibited if it would lead to a firm gaining a dominant position in a substantial market. As a result, few mergers were stopped and some which would probably have substantially lessened competition were allowed to proceed without detailed investigation. Since January 1993 a threshold test of substantial lessening of competition has applied — a reversion to the test included in the original 1974 Trade Practices Act. This is likely to mean that more proposed mergers will come under scrutiny and the trade-offs between efficiency gains and anti-competitive detriments will need to be evaluated in a greater number of individual cases. New draft merger guidelines released in November 1992 generally reflect contemporary thinking in industrial economics.     

2008年中国石油和化学工业经济形势分析

受全球金融危机的影响,2008年中国石油和化学工业经济呈现先高后低的态势,全行业景气周期由10年来的高增长转为下行通道.2008年全行业总产值6.58万亿元,比上年增长24.0%,生产增幅先高后低,年底出现负增长;市场疲软,销售率下降;石油和化工产品价格呈现先涨后跌态势;亏损企业增加,全行业利润下降;固定资产投资增势回落;进出口贸易额先增后降.当前面临的主要困难和问题有:1)石油消费需求减少,炼油企业开工率持续走低;2)化肥库存大量积压,企业经营困难;3)劳动密集型产业亏损严重;4)出口严重受阻,国内市场面临进口产品冲击.未来两年石油和化工行业形势不容乐观.但随着国家相关政策的落实,2009年产业结构、产品结构、企业兼并重组以及企业自身结构调整将非常活跃,前两个季度是石油和化工行业最为困难的时期,下半年有望好转.