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.     

Process safety evaluation applying DIERS methodology to existing plant operations

The DIERS methodology can be used to quickly assess the relief capacity envelope for a collection of existing process vessels accounting for both vapor and gassy systems. Easy-to-use vent sizing nomograms and PRESS sheets are proposed that can be completed by the process engineering, the process chemistry and the process safety departments. A vessel volume-vent size diameter relationship is also developed using the source term based on fire exposure to cover a reasonable range of credible upset scenarios. In this way the adequacy of existing relief systems can be quickly surveyed for potential trouble sources—“outliers”—warranting further evaluation and corrective action.     

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.     

The reactive system screening tool (RSST): An easy,inexpensive approach to the DIERS procedure

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.     

Analysis of diers venting tests: Validation of a tool for sizing emergency relief systems for runaway chemical reactions

A one-dimensional computer model of multiphase, chemically reacting flow has been used to analyze a number of DIERS Phase III venting tests.     

Batch runaway reaction relief: Re-evaluation of “Credible” scenario

Many chemical reactions in the fine chemical and related industries are performed in a semi-batch manner under isothermal conditions. Relief system design evaluation for runaway reactions, using DIERS methodology for example, is frequently studied adiabatically using data derived from batch mode testing. In many cases, however, evaluation of the process isothermally under the realistic semi-batch mode can be extremely useful, often helping to greatly reduce the vent size as a result of a better understanding of the process. In some cases, it is even possible to eliminate runaway reaction as a viable case for relief sizing. Such evaluations of venting are fully consistent with DIERS methodology. This paper presents the arguments for sizing vents for scenarios other than the very worst case, by objective evaluation of trips and interlocks, so that the level of risk is reduced to an acceptable level without the need for extremely large vents.     

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.     

大面积停电应急监控与启动机制设计的探讨

应急机制是应急管理体系的核心内容之一。大面积停电的应急监控与启动机制是启动应急方案之前的基础性机制,探讨其设计形式和内容具有重要意义。介绍了应急机制的含义,在此基础上讨论了在应急监控与启动机制设计中需要注意的预警及其分级、风险源辨识和事件评价指标等问题,以期完善应急方案,提高应急管理水平。     

The use of spreadsheets in modelling accidental releases of toxic chemicals

Many hazardous industrial chemicals are stored as liquidfied compressed gases. To evaluate the possible consequences of a pipeline rupture, hose break, or tank puncture, the safety or process engineer needs a means to estimate the two-phase (liquid and gas) flow rate. Recent technical advances by the American Institute of Chemical Engineers Design Institute of Emergency Relief Systems (DIERS) have produced methods that can be used to compute the two-phase flow rate. These methods are simple and can be completed using a personal computer and a standard spreadsheet program such as Excel (Macintosh) or Lotus (DOS based). This paper presents the two-phase flow rate calculation method and shows how spreadsheets can be used for these calculations.     

Assessing a runaway of a Grignard reaction

The venting and control strategies of a Magnesium Grignard formation reaction were assessed by theoretical predictions of the exotherm and the reaction rate, by simple laboratory measurements of the self heat rate, and by Leung's simplified equations and SAFIRE evaluations, based on DIERS methods. SAFIRE computations showed that the 150 mm dia vent was capable of keeping the reactor pressure below its maximum (MAWP) of 860 kPa for the worst-case exotherm. The response to this evidence was to increase safety protection in the automatic control strategy, following a quantified fault tree analysis of the worst-case runaway scenario.     

Use of DIPPR data in reactive chemical hazard assessment

In the early 1970's AIChE established the concept of Design Institutes. These are cooperative, industrially sponsored research efforts based on getting work done in an area of general interest at low cost to supporters. There are now four active AIChE groups. These are, with date of organization: Design Institute for Physical Property Data (DIPPR), 1978; Research Institute for Food Engineering (RIFE), 1984; Center for Chemical Process Safety (CCPS), 1985; and Center for Waste Reduction Technologies (CWRT), 1989. A fifth, Design Institute for Emergency Relief Systems (DIERS) has completed its work and established a user's group. The subject of this paper, DIPPR, is now in its eleventh year of funded project work. A symposium honoring the completion of DIPPR's tenth year was held in San Francisco in November, 1989. There were 11 papers presented, along with an historical overview. Copies of the 11 papers are available from the Engineering Societies Library in New York City, as Session 40. The papers were published as an AIChE Symposium Series in 1990 [1]. The DIPPR project results that can be used in reactive chemical hazard assessment are highlighted.     

Organizing and strategizing in changing networks: Contributions to theory,methodology and management

Research within the IMP approach holds rich implications for theory development, methodology, and management. Actors operate in networks under volatile conditions. In order to make sense out of such conditions, actors engage through their strategizing in different kinds of networks. Different networks imply different interdependencies that both provide possibilities to pursue own aims and limit the space for strategizing. However, relationships with other actors may have to be redefined or exited to provide possibilities for developing new or different solutions. Hence, strategizing is based on an understanding of the present situation colouring the interpretation of the past and prospects of the future.     

基于场控理论的区域社会经济系统运行管理问题初探

系统科学的产生，使人们对研究对象的认识及研究方法和思路发生了根本性的变化。文章以系统科学为基础，在全面分析系统构成及系统功能势态演化基础上，对系统场及系统场控的作用机理进行了研究，规划和设计了区域社会经济系统运行的系统场控功能，构建了确保地区社会经济系统协调运行的管理机制总体框架，旨在为地区社会经济系统的持续发展和管理监控提供了现实可操作性的参考依据。     

谈中石化油气勘探开发工程监督工作的定位和发展

近年来,中国石油化工股份有限公司围绕油气勘探开发工程监督工作,进行了积极而大胆的探索,形成了具有中石化特色的勘探开发工程监督体制和运行机制,有力地推动了勘探开发目标的实现和质量、投资、效益的提升。但是,人们对勘探开发工程监督工作的定位、性质、重要性、必要性及发展,有着不同的认识和理解,为此,从中石化工程监督面临的形势、勘探开发工程特点及质量特性、勘探开发工程监督工作的定位等方面进行了比较系统的论述,对中石化工程监督工作目标及发展进行了展望。     

Artificial neural networks: A new methodology for industrial market segmentation

Neural networks are a type of artificial intelligence computing that have generated considerable interest across many disciplines during the past few years. The authors explore the potential of artificial neural networks in assisting industrial marketers faced with a segmentation problem by comparing their classification ability with discriminant analysis and logistic regression. The neural networks achieve higher hit ratios on holdout samples than the other methodologies. A marketer in a business-to-business situation may be able to segment a market more accurately, thereby improving efficiency for sales forces and other promotional activities, by using artificial neural networks.     

浅谈如何提高环境应急监测能力

针对环境应急监测在突发性环境污染事件中的作用、要求、现状以及管理特点,分别论述了风险源识别、敏感环境调查、污染预防、应急监测体系建设、软硬件建设、应急监测演练等环节对提高环境应急监测速度及应急监测能力的重要性。研究结果对应急监测机构快速、高效地应对环境应急监测工作和保证应急监测质量具有一定的现实指导意义。     

旧城改造背景下旧建筑再利用的政策实施

在城市改造过程中,引起人们广泛关注的是大量的旧建筑处理问题。由于人们对旧建筑再利用的价值认识参差不齐,标准不统一,动机多样化,使得一些原本有保存价值的旧建筑不断被拆除,由此造成了环境污染和资源浪费、城市机理退化等问题。为扩大我国旧建筑再利用的实施范围,分析了旧建筑再利用的经济、生态、社会和文化价值,通过总结发达国家及地区在旧城改造方面的成功经验,综合旧建筑再利用的方法,提出了适合我国国情的旧建筑再利用的措施。     

油库区火灾应急过程风险因素-事故情景结构方程模型研究

为了探讨油库区火灾应急过程中风险因素与事故情景间的量化作用关系，揭示事故发展演化的基本规律，通过对近50年来国内外240例油库区典型火灾爆炸事故的统计分析，从人-物-环境-管理4个方面，建立了二者间的结构方程模型。结果表明：各因素与情景间影响关系显著，其中人的因素影响系数最大，为0.46，且对火灾扩大的情景影响更大，而“误判断”这一具体因素事件最易发生。所构建的结构方程模型能较清晰地量化应急过程风险因素与情景间的作用关系，可为揭示事故发生发展的作用机理提供一定的科学依据，同时为油库区火灾事故应急安全管理提供参考。     

Texas 9-1-1: Emergency telecommunications and the genesis of surveillance infrastructure

Infrastructures of surveillance—everyday, taken-for-granted, institutionalized and technically mediated practices which identify, observe, and analyze individual actions—permeate society. These infrastructures mediate the production of social knowledge and action toward individuals. This article examines the genesis of one such infrastructure, namely the coordinated practices of identifying and locating mobile phone users during emergency (9-1-1) calls. Implementing this infrastructure has entailed creating and coordinating systems to locate wireless phones, to deliver the emergency calls to the appropriate service agency, and to deliver appropriate services to the emergency event. This implementation has occurred within historically specific regulatory, political, cultural, technological, and economic contexts and has specific implications for general surveillance practice. Focusing primarily on the state of Texas, this article examines the development of systems which store and deliver individuals’ geographic location. It argues that, despite privacy laws tightly restricting the use of information generated in the 9-1-1 process, and despite the special purpose to which the 9-1-1 system is dedicated, the wireless 9-1-1 initiative has created the infrastructure for a general purpose locational surveillance infrastructure capable both of surveilling broad patterns of activities and of responding to particular individuals. Moreover, the infrastructure is more available to police agencies and to well-established and well-funded corporate entities than to grass roots organizations. This trend is driven by the need to coordinate a national emergency response system within a fractured telecommunication industry, by the desire of marketers to understand and address their customers’ habits of mobility, and by an increasing willingness of police agencies to include widespread surveillance under the rubric of “emergency services.” Policy responses such as greater ability to opt out of the surveillance system, public oversight of emergency operations, and greater public access to the infrastructure itself might mitigate the most harmful potential social effects of this infrastructure, while distributing its benefits in a more democratic and egalitarian way.     

买方市场条件下大型一体化煤炭企业运营方略

探讨了买方市场条件下,我国大型一体化煤炭企业在运营中日益暴露出来的一系列问题,主要涉及目标定位、项目规划、计划编制、定价机制、考核制度、预警机制、应急预案和标准化建设等方面,并在此基础上提出了相应的改进建议。