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2、on. It may not be provided to any other person in print, electronic, or any other form. Violations of ISAs copyright will be prosecuted to the fullest extent of the law and may result in substantial civil and criminal penalties. TECHNICAL REPORT ISA-TR84.00.04-2005 Part 2 Example Implementation of A
3、NSI/ISA-84.00.01-2004 (IEC 61511 Mod) Approved 1 December 2005 ISA-TR84.00.04-2005 Part 2 - Example Implementation of ANSI/ISA-84.00.01-2004 (IEC 61511 Mod) ISBN: 1-55617-980-4 Copyright 2005 by ISA. All rights reserved. Not for resale. Printed in the United States of America. No part of this public
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5、- 3 - ISA-TR84.00.04-2005 Part 2 Copyright 2005 ISA. All rights reserved. Preface This preface, as well as all footnotes and annexes, is included for information purposes and is not part of ISA-TR84.00.04-2005 Part 2. This document has been prepared as part of the service of ISA toward a goal of uni
6、formity in the field of instrumentation. To be of real value, this document should not be static but should be subject to periodic review. Toward this end, the Society welcomes all comments and criticisms and asks that they be addressed to the Secretary, Standards and Practices Board; ISA; 67 Alexan
7、der Drive; P. O. Box 12277; Research Triangle Park, NC 27709; Telephone (919) 549-8411; Fax (919) 549-8288; E-mail: standardsisa.org. It is the policy of ISA to encourage and welcome the participation of all concerned individuals and interests in the development of ISA standards, recommended practic
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14、SE SOUND PROFESSIONAL JUDGMENT CONCERNING ITS USE AND APPLICABILITY UNDER THE USERS PARTICULAR CIRCUMSTANCES. THE USER MUST ALSO CONSIDER THE APPLICABILITY OF ANY GOVERNMENTAL REGULATORY LIMITATIONS AND ESTABLISHED SAFETY AND HEALTH PRACTICES BEFORE IMPLEMENTING THIS DOCUMENT. THE USER OF THIS DOCUM
15、ENT SHOULD BE AWARE THAT THIS DOCUMENT MAY BE IMPACTED BY ELECTRONIC SECURITY ISSUES. THE COMMITTEE HAS NOT YET ADDRESSED THE POTENTIAL ISSUES IN THIS VERSION. ISA-TR84.00.04-2005 Part 2 4 Copyright 2005 ISA. All rights reserved. This ISA technical report was prepared by ISA-SP84 Working Group 2, wh
16、ich included the following members: NAME COMPANY A. Summers, ISA-SP84 WG2 Leader SIS-TECH Solutions LLC W. Johnson, ISA-SP84 Chair E.I. Du Pont V. Maggioli, ISA-SP84 Managing Director Feltronics Corp. R. Dunn, ISA-SP84 Recorder DuPont Engineering R. Adamski Premier Consulting Services H. Bezecny Dow
17、 Deutschland D. Bolland ExxonMobil Research and Process Industry Practices (PIP), Safety Instrumented Systems Guidelines, available from: Process Industry Practices (PIP), 3925 West Braker Lane (R4500), Austin, TX 78759, Tel: (512) 232-3041, www.PIP.org. The example is modified to meet ANSI/ISA 84.0
18、0.01-2004 (IEC 61511 Mod) requirements. This example was chosen to facilitate understanding of SIS application as it progressed from CCPS Guidelines dated 1993 to ANSI/ISA S84.01-1996, to ANSI/ISA 84.00.00.01-2004 (IEC 61511 Mod). This example was also used in Appendix B of AIChE, CCPS, Layer of Pro
19、tection Analysis, Simplified Process Risk Assessment, 2001. 1 Introduction Used in conjunction with ISA-TR84.00.04-2005 Part 1, the example set forth in this technical report is provided to illustrate how to apply ANSI/ISA-84.00.01-2004 Parts 1-3 (IEC 61511Mod). It is intended to demonstrate one met
20、hod to meet the requirements of the standards. The reader should be aware that ANSI/ISA-84.00.01-2004 Parts 1-3 (IEC 61511 Mod) is performance based, and that many approaches can be used to achieve compliance. Some of the methods applied in this example include: what-if and HAZOP techniques for haza
21、rd and risk analysis, LOPA for allocation of safety functions to protection layers, fault tree analysis for SIL verification, and ladder logic to document the application software requirements. Other techniques and tools could be utilized at each of these steps in the safety lifecycle to meet the re
22、quirements of the standards. NOTE Throughout this technical report, the term “ISA-84.01-2004” is used to refer to ANSI/ISA-84.00.01-2004 Parts 1-3 (IEC 61511 Mod). The example utilizes the similar chemical process presented in AIChE CCPS, Guidelines for Safe Automation of Process Applications, 1993,
23、 and in PIP PCESS001 1999, Safety Instrumented Systems Guidelines. The safety lifecycle application in the CCPS version was based on the initial version of IEC 61508. The safety lifecycle application in the PIP version was based on ANSI/ISA-S84.01-1996. The safety lifecycle example herein is based o
24、n ISA-84.01-2004. As a result, the evolution of new design requirements can be assessed by comparing this example with previous versions. This example selects a subsystem of a process and applies to it the design philosophy, procedures, techniques, and verification methodology discussed in ISA-84.01
25、-2004. This example shows cradle-to-grave documentation for each SIF. This documentation pedigree gives auditors and plant personnel the means to track the SIF through the safety lifecycle phases back to the process hazards analysis (PHA) that created it. Each SIF is clearly identified in each docum
26、ent to facilitate tracking between lifecycle phases. A vital part of safety is the ability to demonstrate to others (e.g., auditors, regulators, insurance companies) that the risk reduction provided by each SIF is adequate. This example does not represent a complete design for a polymerization proce
27、ss because of the extensive detail that is required to achieve a high-integrity, safely automated design. As a result, this example includes a number of simplifications. All references shown refer to information within this example unless otherwise noted. 2 Project Definition The process is the poly
28、merization of vinyl chloride monomer (VCM), CH2=CHCl to make polyvinyl chloride (PVC), CH2CHClnISA-TR84.00.04-2005 Part 2 10 Copyright 2005 ISA. All rights reserved. The example involves a hazardous reactant, VCM, which is flammable and has toxic combustion products, as well as being a known carcino
29、gen. The process also illustrates a larger-scale batch operation that operates in a semi-continuous manner during an approximately 10-hour period while the polymerization progresses. A simplified description of the process steps is also provided. 2.1 Conceptual Planning Once a business decision is m
30、ade to consider producing a certain productin this example, polyvinyl chloridethe initial project team is assembled. This team will start by evaluating potential process routes to identify a technology that will satisfy production needs while meeting responsibilities for health, safety, and protecti
31、on of the environment. 2.2 Process Hazards Analysis In the very early stages of process evaluation and project definition, a process hazards analysis team (in this example, P.H.A. Smith, Process Jones, S. Bulk, V. May, R. Brown, W. Burk, A.C. Green) starts to interact closely with the designers. For
32、 projects handling hazardous materials, the team will include not only process design engineers but also health and safety specialists. The team will often need to have access to other specialistssuch as chemists, operating personnel, consultants or engineering contractors having experience with the
33、 same or similar processes, and process licensors. In this example, a well-proven process is available as a starting point. Therefore, we will proceed with the business decision to produce this product, and concentrate on the aspects of the design process that influence or directly involve the desig
34、n of the process control systems and safety interlock systems. More detailed information on related aspects of the design process can be found in the following list of texts from the Center for Chemical Process Safety, American Institute of Chemical Engineers: Guidelines for Hazard Evaluation Proced
35、ures Guidelines for Chemical Process Quantitative Risk Analysis Guidelines for Safe Storage and Handling of High Toxic Hazard Material Guidelines for Vapor Release Mitigation Guidelines for the Technical Management of Chemical Process Safety. 3 Simplified Process Description The manufacture of PVC f
36、rom the monomer is relatively straightforward. The heart of the process is the reactor vessel in which the polymerization takes place over a period of about ten hours, while the reactor contents are agitated mechanically and the heat of reaction is removed by the circulation of cooling water through
37、 the reactor jacket. Because the process involves the charging of a batch to the reactor, process systems are designed with multiple reactor units in parallel, so that the process can operate on a semi-continuous basis. For simplicity, this example will focus on one of the units, recognizing that a
38、real production facility will typically have several parallel units operating in sequence. 11 ISA-TR84.00.04-2005 Part 2 ReactorExternalCoolingWaterExternalSteamShortstop WaterInitiatorFresh VCMSurfactantsSlurryDegassingSectionSlurrySurgeDrumsSlurryStrippingSectionResin Dewater/Dry Resin Blender Res
39、in StorageRecoveredVCM (Recycle)VCM GasRecoveryCompressorsRecycle VCMGasGasFigure 1 Simplified flow diagram: the PVC process Figure 1 is a simplified process flow diagram for a typical PVC manufacturing facility. If the reactor vessel has been opened for maintenance after the last batch was processe
40、d and dumped, it must first be evacuated to remove any residual air (oxygen) in the vapor space, to minimize the oxidation reaction of monomer which produces HCl and may lead to stress corrosion damage to the reactor vessel as well as to poor product quality. Otherwise, the first step is to treat th
41、e reactor vessel with anti-foulant solution to prevent polymerization on the reactor walls. This is followed by charging the vessel with de-mineralized water and surfactants. Then, the liquid vinyl chloride monomer (VCM) charge is added at its vapor pressure (about 56 psig at 70F). The reaction init
42、iator is a peroxide that is dissolved in a solvent. Since it is fairly active, it is stored at cold temperatures in a special bunker. Small quantities are removed for daily use in the process and are kept in a freezer. It is first introduced into a small charge pot associated with the reactor to ass
43、ure that only the correct quantity is added. After the reaction initiator is introduced, steam-heated water is applied to the reactor jacket to raise the temperature to about 130 to 140 F (depending on the batch recipe for the particular grade of product), where the reaction will proceed at a satisf
44、actory rate. Agitation is necessary to suspend the VCM in the water (control particle size), improve heat transfer throughout the batch, and produce a uniform product. Since the reaction is exothermic, cooling water is then circulated through the vessel jacket to control the reactor temperature. Rea
45、ctor conditions are controlled carefully during the approximately eight hours required for completion of the polymerization. The reaction is completed when the reactor pressure decreases, signaling that most of the monomer has reacted. Reacted polymer is dumped from the reactor and sent to downstrea
46、m process units for residual VCM recovery, stripping, dewatering, and drying. Copyright 2005 ISA. All rights reserved. ISA-TR84.00.04-2005 Part 2 12 Copyright 2005 ISA. All rights reserved. 4 Preliminary Design All special local requirements are reviewed, applicable regulations are identified, and g
47、eneral risk guidelines are established. Utility requirements (e.g., air, cooling water, electrical power) are reviewed and confirmed to be adequate for the application. 5 ISA-84.01-2004 Application When the preliminary planning is complete (see clauses 1 through 3 inclusive), the implementation of I
48、SA-84.01-2004 is begun. For this example the design strategy is to initialize the lifecycle design (Figure 2) and break down the lifecycle phases into ten steps consistent with Figure 2 and Table 1 (safety lifecycle overview). At this point in the project, it may be beneficial to use the lifecycle t
49、able to assign responsibility for each lifecycle phase as shown in Table 1. 13 ISA-TR84.00.04-2005 Part 2 Design anddevelopment of othermeans ofrisk reductionClause 9Hazard and riskassessmentClause 8Manage- ment of nd functionalsafetyandfunctionalsafetyassess-ment aauditingClause 5Safety .2lifecycle structureandplanningClause 6Design and engineeri ong fsafety instrumented systemClauses 11 and 124 Installation, cvalidommissioningationand Clauses 14 and 155Operation and maintenance66 Clause 1Modification7 Clause 17Verifica-ti
