ISA IND FLW MEASRMNT-2005 Industrial Flow Measurement (Third Edition).pdf

1、Industrial Flow Measurement3rd EditionSpitzer04.book Page i Wednesday, August 11, 2004 3:45 PMSpitzer04.book Page ii Monday, August 30, 2004 10:15 PMIndustrial FlowMeasurement3rd EditionDavid W. SpitzerNoticeThe information presented in this publication is for the general education of the reader. Be

2、cause neither the author nor the publisher have any control over the use of the information by the reader, both the author and the publisher disclaim any and all liability of any kind arising out of such use. The reader is expected to exercise sound professional judgment in using any of the informat

3、ion presented in a particular application.Additionally, neither the author nor the publisher have investigated or considered the affect of any patents on the ability of the reader to use any of the information in a particular application. The reader is responsible for reviewing any possible patents

4、that may affect any particular use of the information presented.Any references to commercial products in the work are cited as examples only. Neither the author nor the publisher endorse any referenced commercial product. Any trademarks or tradenames referenced belong to the respective owner of the

5、mark or name. Neither the author nor the publisher make any representation regarding the availability of any referenced commercial product at any time. The manufacturers instructions on use of any commercial product must be followed at all times, even if in conflict with the information in this publ

6、ication.Copyright 2005 ISA The Instrumentation, Systems, and Automation SocietyAll rights reserved. Printed in the United States of America. 10 9 8 7 6 5 4 3 2ISBN No part of this work may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical

7、, photocopying, recording or otherwise, without the prior written permission of the publisher.ISA67 Alexander DriveP.O. Box 12277Research Triangle Park, NC 27709Library of Congress Cataloging-in-Publication DataSpitzer, David W. Industrial flow measurement / David W. Spitzer.- 3rd ed. p. cm. ISBN 1-

8、55617-871-9 (pbk.) 1. Flow meters. I. Title. TJ935.S58 2004 681.28-dc22 2004012436DedicationThis work is dedicated to my children, Deborah Goldie and Michael James, in the hope that it will inspire them to continue their education and their pursuit of knowledge, and to my wife Ida for understanding

9、why I was so early to rise and late to bed for so many months.Spitzer04.book Page v Monday, August 30, 2004 10:15 PMSpitzer04.book Page vi Monday, August 30, 2004 10:15 PMviiContentsPreface Why Measure Flow? xiiiAbout the Author xvAbout the Book xviiAcknowledgments xixChapter 1 INTRODUCTION 1Objecti

10、ves, 1Prerequisites and Audience, 2Learning Objectives, 2Chapter 2 FLUID FLOW FUNDAMENTALS 3Introduction, 3Temperature, 3Pressure, 4Expansion of Liquids, 8Expansion of Solids, 8Expansion of Gases, 10Specific Gravity, 16Flow, 17Inside Pipe Diameter, 19Kinematic Viscosity, 27Dynamic (Absolute) Viscosi

11、ty, 27Velocity Profile and Reynolds Number, 32Newtonian and Non-Newtonian Liquids, 36Friction Losses, 37Miscellaneous Hydraulic Phenomena, 44Spitzer04.book Page vii Monday, August 30, 2004 10:15 PMviii Industrial Flow MeasurementChapter 3 PERFORMANCE MEASURES 49Introduction, 49Performance Statements

12、, 49Repeatability and Hysteresis, 53Linearity, 54Accuracy, 56Composite Accuracy, 59Turndown, 61Rangeability, 61Long Term Stability, 61Chapter 4 LINEARIZATION AND COMPENSATION 63Introduction, 63Linear and Nonlinear Flowmeters, 63Gas Flow Pressure and Temperature Compensation, 65Liquid Temperature Com

13、pensation, 67Pressure and Temperature Tap Location, 70Flow Computers, 70Multivariable Flowmeters, 71Chapter 5 TOTALIZATION 73Introduction, 73Analog and Digital Flowmeters, 73Implementation, 75Chapter 6 FLOWMETER CALIBRATION 79Introduction, 79Calibration Techniques, 79Dry Calibration, 81Verification

14、of Operation, 85Chapter 7 MEASUREMENT OF FLOWMETER PERFORMANCE 87Introduction, 87Applicable Range, 87Flowmeter Composite Accuracy, 88Transmitter Accuracy, 88Linearization Accuracy, 89Digital Conversion Accuracy, 90Indicator Accuracy, 91Totalization Accuracy, 91Overall Flowmeter System Accuracy, 91Sp

15、itzer04.book Page viii Monday, August 30, 2004 10:15 PMTable of Contents ixChapter 8 MISCELLANEOUS CONSIDERATIONS 97Introduction, 97Materials of Construction, 97Piping Considerations, 100Safety, 107Wiring, 108Chapter 9 INTRODUCTION TO FLOWMETERS 111Introduction, 111Flowmeter Classes, 111Flowmeter Ty

16、pes, 113Introduction to Flowmeter Technology Sections, 115Chapter 10 DIFFERENTIAL PRESSURE FLOWMETERS 117Introduction, 117Orifice Plate Flowmeters, 117Other Technologies, 151Chapter 11 MAGNETIC FLOWMETERS 161Introduction, 161Principle of Operation, 161Construction, 168Operating Constraints, 172Perfo

17、rmance, 173Applications, 174Sizing, 174Installation, 175Maintenance, 181Chapter 12 MASS FLOWMETERS 185Introduction, 185Coriolis Mass Flowmeters, 185Hydraulic Wheatstone Bridge, 198Chapter 13 OPEN CHANNEL FLOWMETERS 201Introduction, 201Weirs, 201Parshall Flumes, 205Chapter 14 OSCILLATORY FLOWMETERS 2

18、11Introduction, 211Fluidic Flowmeters, 211Vortex Precession Flowmeters, 216Maintenance, 217Vortex Shedding Flowmeters, 218Spitzer04.book Page ix Monday, August 30, 2004 10:15 PMx Industrial Flow MeasurementChapter 15 POSITIVE DISPLACEMENT FLOWMETERS 245Introduction, 245Helical Gear Positive Displace

19、ment Flowmeter, 247Nutating Disc Positive Displacement Flowmeter, 253Oscillating Piston Positive Displacement Flowmeter, 256Oval Gear Positive Displacement Flowmeter, 261Piston Positive Displacement Flowmeter, 270Rotary Positive Displacement Flowmeter, 277Chapter 16 TARGET FLOWMETERS 283Introduction

20、, 283Principle of Operation, 283Construction, 284Performance, 287Applications, 287Sizing, 288Installation, 289Maintenance, 291Chapter 17 THERMAL FLOWMETERS 293Introduction, 293Principles of Operation, 293Construction, 296Operating Constraints, 298Performance, 298Applications, 299Sizing, 299Installat

21、ion, 300Maintenance, 300Chapter 18 TURBINE FLOWMETERS 303Introduction, 303Axial Turbine Flowmeters, 303Other Turbine Flowmeter Designs, 315Chapter 19 ULTRASONIC FLOWMETERS 319Introduction, 319Principle of Operation, 319Construction, 324Operating Constraints, 325Performance, 326Applications, 327Sizin

22、g, 327Installation, 328Maintenance, 329Spitzer04.book Page x Monday, August 30, 2004 10:15 PMTable of Contents xiChapter 20 VARIABLE AREA FLOWMETERS 331Introduction, 331Principle of Operation, 331Construction, 332Operating Constraints, 337Performance, 338Applications, 339Sizing, 339Installation, 341

23、Maintenance, 342Chapter 21 CORRELATION FLOWMETERS 345Principle of Operation, 345Chapter 22 INSERTION FLOWMETERS 351Introduction, 351Principle of Operation, 351Available Technologies, 357Operating Constraints, 361Performance, 363Applications, 363Sizing, 363Installation, 364Maintenance, 366Chapter 23

24、BYPASS FLOWMETERS 369Introduction, 369Principle of Operation, 369Types of Bypass Flowmeters, 370Chapter 24 FACTORS IN FLOWMETER SELECTION 373Introduction, 373Flowmeter Categories, 373Flowmeter Types, 374Performance, 375End Use, 376Power Requirement, 377Safety, 378Rangeability, 378Materials of Constr

25、uction, 378Maintainability, 378Ease of Application, 379Ease of Installation, 379Installed Cost, 379Operating Cost, 380Maintenance Cost, 380Spitzer04.book Page xi Monday, August 30, 2004 10:15 PMxii Industrial Flow MeasurementChapter 25 DATA REQUIRED FOR FLOWMETER SELECTION 387Introduction, 387Perfor

26、mance, 388Fluid Properties, 389Installation, 391Operation, 392Future Considerations, 393Risk, 393Flowmeter Information Sheet, 393Chapter 26 FLOWMETER SELECTION PROCEDURE 395Introduction, 395Flowmeter Selection Procedure, 395Applications, 398Appendix A REFERENCES 425Appendix B ANSWERS TO EXERCISES 42

27、7INDEX 439Spitzer04.book Page xii Monday, August 30, 2004 10:15 PMxiiiPrefaceWhy MeasureFlow?Virtually all technical books contain introductions that expound upon the impor-tance and applicability of the contents. In reality, these sections are rarely read,because the general information adds little

28、 or nothing to the overall technical con-tent of the book.Often, that which is not presented can be a books most valuable lesson. Con-sider giving a person clear, verbal directions on how to get from one location toanother, understanding that the route may not be the shortest. Teach that same per-so

29、n how to read a map, and he or she can determine the best route to anywhere inthe world.The content of this book is a “map” comprised of numerous pieces of infor-mation that supply the answers to questions that provide an understanding of thesubject. Knowing when to read this “map” entails intimate

30、knowledge of the pro-cess and the laws that govern it.Most individuals succumb to pressure and are content to find the quick solu-tion to a perceived problem. This approach usually yields less than optimumresults and may even camouflage real problems.To effectively apply information, one must think.

31、 Even though most individu-als are capable of logical though, the process of defining the real problem beforefinding a solution occurs far too infrequently. The real problem and a good solu-tion thereto must be determined before one can decide whether the content of thisbook is truly applicable and

32、useful.Spitzer04.book Page xiii Monday, August 30, 2004 10:15 PMSpitzer04.book Page xiv Monday, August 30, 2004 10:15 PMxvAbout the AuthorDavid William Spitzer is a principal of Spitzer and Boyes, LLC, where he is aconsultant practicing instrumentation, flow, measurement, and process controlengineer

33、ing. In addition, he provides product development, marketing, and distri-bution channel services. He was previously the Manager of Utility and Instrumen-tation Engineering at Nepera, Inc., Harriman, NY, where he was responsible fortechnical support and direction in the electrical, instrumentation, a

34、nd utility areason a plant-wide basis.Mr. Spitzer serves on the American Society of Mechanical Engineers Com-mittee on Measurement of Fluid Flow in Closed Conduits. He is also a member ofthe editorial advisory board of INTECH, INTECH Brasil, and Flow Control mag-azines.A frequent instructor at the I

35、SA Training Center in Raleigh, NC, and through-out the United States and internationally in the Short Course Program, Mr. Spitzeris the author of Variable Speed Drives, Principles and Applications for EnergyCost Savings. He is also Volume Editor of Flow Measurement, part of ISAs Prac-tical Guides fo

36、r Instrumentation and Control Series and author of various booksabout flowmeters in “The Consumers Guide to” series.Spitzer04.book Page xv Monday, August 30, 2004 10:15 PMSpitzer04.book Page xvi Monday, August 30, 2004 10:15 PMxviiAbout theBookModern flowmeters handle many more applications than cou

37、ld have been imag-ined centuries ago. Todays flow measurements encompass operating conditionsthat range from capillary blood flow, flows over spillways, flow of gases, plas-mas, pseudo-plastics, solids, and corrosives, to name but a few. This text reviewsthe important concepts of flow measurement an

38、d provides explanations, practicalconsiderations, illustrations, and examples of existing flowmeter technologies. Itpresents a rational procedure for flowmeter selection that is based on factual infor-mation. This text is directed to technical personnel involved with flow measure-ment from technicia

39、ns through engineers and managers, to scientists. Salesengineers and instructors at community colleges and technical schools may alsobenefit.Spitzer04.book Page xvii Monday, August 30, 2004 10:15 PMSpitzer04.book Page xviii Monday, August 30, 2004 10:15 PMxixAcknowledgmentsMy involvement in the deve

40、lopment of this text and the “Industrial Flow Mea-surement” Short Course offered by ISA is a result of some degree of luck, coinci-dence, and lots of long hours and hard work. David Bartran of SpectrumEngineering, Inc., thoroughly and frankly reviewed the rough draft and offeredmuch in the way of in

41、cisive, constructive criticism and suggestions. I would liketo thank Mobay Chemical Corporation and Nepera, Inc., for making possible theuse of their word processing systems before and after working hours.At times mention is made of specific products and manufacturers, and refer-ences to particular

42、instrument types are included. This was done in an effort toexplain measurement techniques and the principles involved. The choices madewere based on personal experience and knowledge and should in no way be con-strued as suggesting endorsement of any instrument type or manufacturer byeither the aut

43、hor or ISA.Spitzer04.book Page xix Monday, August 30, 2004 10:15 PMSpitzer04.book Page xx Monday, August 30, 2004 10:15 PM11IntroductionFlow measurement technology has evolved rapidly in recent decades. Some tech-nologies have survived, while others have fallen by the wayside or have neverbeen comme

44、rcially developed. Physical phenomena discovered centuries agohave been the starting point for many viable flowmeter designs. In recent years,technical developments in other fields, namely in optics, acoustics, and electro-magnetism, have resulted not only in improved sensor designs but also in newf

45、lowmeter concepts.This technology “explosion” has enabled modern flowmeters to handle manymore applications than could have been imagined centuries ago. Todays flowmeasurements encompass operating conditions that range form capillary bloodflow to flows over spillways, flows of gases, plasmas, pseudo

46、-plastics, solids, andcorrosives, to name but a few.Effective flowmeter selection requires a thorough understanding of flowmetertechnology in addition to a practical knowledge of the process and the fluid beingmeasured. The difficulty in bringing these two facts of flow measurement to bearon a pract

47、ical application is challenging even to experienced engineers, techni-cians, and sales personnel.ObjectivesThe primary objective of this text is to review the important concepts of flow mea-surement and to provide explanations, practical considerations, illustrations, andexamples of existing flowmet

48、er technologies. The ultimate goal is to present arational procedure for flowmeter selection based on factual information. The title,Industrial Flow Measurement, was chosen to emphasize the goal of presenting theknowledge with which practical and precise industrial measurements can bemade. A purely

49、mathematical treatment of flowmeters is avoided in favor of heu-ristic explanations of the principles and installation considerations involved andhow they apply to a given flowmeter.Spitzer04.book Page 1 Monday, August 30, 2004 10:15 PM2 Industrial Flow MeasurementPrerequisites and AudienceThis text is intended as an introduction to flowmeter technology and has applica-tion for sales personnel, technicians, engineers, instructors, and those who areendeavoring to broaden their knowledge of industrial flow measurement. It canbe used by persons without