Mgchanica! Designof Process Systems

Volume2Shell-and-Tube Heat Exchangers

Rotating EquipmentBins, Silos, Stacks

A.Keith Escoe

Gulf Publishing CompanyBook Division

Houston, London, Paris, Tokyo

llctaniul Design

of Pmctss Svsterns

\itme 2

SldLen*Tuh Heat Exchangers o

Roadng Equipnent r Bins, Silos, Stacks

Copl right @ 1986 by Gulf Publishing Company, Houston, Texas.

All righrs reserved. Printed in the United States of America. Thisb@k. or parts thereof, may not be reproduced in any form withoutp.rmission of the publisher.

Llbiary ol Congress Calaloging-in-Publicalion Data

Escoe. A. Keith.\lechanical design of process systems.

l-ocludes bibliographies and indexes.Conr€Drs: v. l. Piping and pressure vessels-v. 2. Shell-and-tube

bear exchangers; rotating equipment; bins, silos, stacks.l- Ch€mical plants Design and construction.

I- Tirle-TPI55.5.E83 1986 660.2 ', 81

lS€fl O.ATant -562-9 (v 1)

6aaa (}ET2l)1-565-3 (v. 2)

85-22005

iv

Contents

Foreword ........viiby John J. McKetta

Preface ..........ixChapter 5The Engineering Mechanics of Bins, Silos,and Stacks ........1

Silo and Bin Design, IStack Design, 8

Vortex Shedding and Frequency Responsc.Ovaling. Helical Vortex Breaker Strakes.

Example 5-l: Granule Bin Design for RoofingPlant, 11

Bin Stiffener Design. Vcssel Supports.

Example 5-2: High-Pressure Flare Stack Design, 20Effective Diameters. SectionWeights-Uncorroded weight. Required tThickness. Anchor Bolt Design. CantileverVibration. Static Deflection. DynamicDeflection. Anchor Bolt Torque. DesignSummary.

Example 5-3: Stack Vortex Strake Design, 27Example 5-4: Natural Frequency of Ovaling

Ring Formula (Michell Formula), 28Notation,29References, 29

Chapter 6Rotating Equipment ......31

Pumps, 31Centrifugal Pumps. Hydraulic Requirements ofCentrifugal Pumps. Positive DisplacementPumps. Pressure Protection for PositiveDisplacement Pumps.

Compressors,43Principles of Compression. ReversibleAdiabatic (lsentropic) Compression. PolytropicCompression. Isothermal Compressron.Dimensionless Reference Numbers. CentrifugalCompressors. Reciprocating Compressors.\{ulriple Staging of Reciprocating Compressors.Cas Temperature for ReciprocatingCompressors. Axial Flow Compressors.Specirying Compressor Flow Conditions. MassFlow. Actual or lnlet Volumetric Flow.Standard Volumetric Flow. Properly SpecifyingCompressor Flow Conditions.

Piping Systems for Rotating Equipment, 60Nozzle Loadings.

Pulsation Response Spectra Induced byReciprocating Equipment, 62

Example 6-l: Horizontal Centrifugal PumpSysrem Design, 65

Suction Line Pressure Drop. K-Values.Discharge Line Pressure Drop. The Effects ofLiquid Viscosity on Centritugal Pumps.

Example 6-2: Positive Displacement PumpDesign,74

Suction Line Pressure Drop. K-Values. A wordAbout Priming.

Example 6-3: Centrifugal Compressor Selection,Example 6-4: Installing a Compressor at

Elevation, 34Selecting the Reciprocating Compressor.

Example 6-5: Naphtha Pump System Design, 86Flow from Reservoir to Naphtha Storage Tank.Naphtha Pump Hydraulics. The MaximumCapacity Condition. Reevaluation of ReservoirLine.

Notation,9TReferences, 97

79

Chapter 7The Mechanical Design of Shell-and-Tube HeatExchangers ...... 99

Fundamentals of Shell-and-Tube HeatExchangers,99

Design Classifications of Heat Exchangers.Fixed Tubesheet Shell-and-Tube HeatExchangers. U-Tube Shell-and-Tube HeatExchangers. Floating Head Shell-and-Tube HeatExchangers. General TEMA ExchangerClasses-R, C, and B. Basic Components ofShell-and-Tube Heat Exchangers. TEMAFormulations. ASME TUbe Joint Load Criteria.

Process Evaluation of Shell-and-TirbeExchangers, 115

Tube Wall Temperature and CaloricTemperaturc. Overall Heat TransferCoefficient. Fouling of Inside and Ourside TubeSurfaces. Tube Film Coefficients.

Tube Vibrations, 139Plate-Fin Heat Exchangers, 147Example 7-1: Regenerated Gas Exchanger

Design, 148Tube-Side Film Coefficient. Shell-Side FilmCoefficient. Shell-Side Pressure Drop.

Example 7-2: Vibration Check for RegeneratedGas Exchanger, 153

Example 7-3: Chlorine Superheater Design, 154Tube-Side Film Coefficient. Shell-Side FilmCoefficient. Shell-Sid€ Pressure Drop. TUbeMetal Temperature.

Example 7-4: Asphalt Coating Mix Heater-ANon-Newtonian Fluid Application, 160

Tube-Side Film Coefficient. Shell-Side FilmCoefficient. Shell-Side Pressure Drop.

Example 7-5: Zero LMTD Exchanger, 165Notation, 165References, 166

Chapter 8External Loadings on Shell Structures .... 169

Lifting Lug Design, 170Example 8-1: Lifting Lug Design and Location, 170Notation, 175References, 176

Appendix APartial Volumes and Pressure VesselCafcufations ....,177

Partial Volume ofa Cylinder, 177Partial Volume of a Hemispherical Head, 177Partial Volumes of Spherically Dished Heads, 178Partial Volumes of Elliptical Heads, 179Partial Torispherical Heads, 181Internal Pressure ASME Formulations with

Outside Dimensions, 183Internal Pressure ASME Formulations with Inside

Dimensions, 184

Appendix BNational Wind Design Standards ......... 187

Criteria for Determining Wind Speed, 187Wind Speed Relationships, 188ANSI A58.1-1982 Wind Categories, 189

Appendix GProperties ot Pipe . . ..... 193

Insulation Weight Factors, 200Weights of Piping Materials, 201

Appendix DConversion Factors . .....225

Alphabetical Conversion Factors, 226Synchronous Speeds, 233Temperature Conversion, 234Altitude and Atmospheric Pressures, 235Pressure Conversion Chart, 236

vl

The engineer who understands the impact of process

design decisions on mechanical design details is in a po-sition to save his client or his company a lot of money.

That is because the test of any process design is in howcost-effectively it yields the desired product, and how"cost" generally translates to "equipment": How muchwill the process require? How long will it last? Howmuch energy will it consume per unit of product?

In this two-volume work on Mechanical Design ofProcess Systems, A. K. Escoe has performed a monu-mental service for mechanical design engineers andchemical process engineers alike. The information ispresented in such a manner that even the neophyte engi-neer can grasp its full value. The author has produced anin-depth review of the way in which process design spec-ifications are interpreted into precise equipment designs.Perhaps most valuable of all are the extensiv e worked ex-amples throvghout the text, of actual designs that havebeen successfully executed in the field.

The piping system is the central nervous system of a

fluid flow process, and the author has treated this withproper respect in two excellent chapters on fluid me-

t'oreword

chanics and the engineering mechanics of piping (Vol-ume 1).

The chapter on heat transfer in vessels and piping il-lustrates lucidly the interrelationship between process

and mechanical design. Every engineer working with in-dustrial process systems will benefit from reading thischaDter.

Although the author has made a herculean effort incovering the mechanical design of pressure vessels, heatexchangers, rotating equipment, and bins, silos andstacks (Volume 2), it is true that there are omissions. It ishoped that, as the author hints in his preface, a futurevolume might be added covering multiphase flow, spe-cific cogeneration processes, turbines, and detailed pip-ing dynamics.

Still, at this writing these two volumes comprise anoutstanding practical reference for chemical and me-chanical engineers and a detailed instructional manualfor students.

I recommend these volumes highly for each design en-gineer's professional library.

John J. McKexa, Ph.D. , PE.Joe C. Waher Professor of Chemical Engineering

Universitv of kxas, Austin

vtl

This book's purpose is to show how to apply mechani-cal engineering concepts to process system design. Pro-cess systems are common to a wide variety of industriesincluding petrochemical processing, food processing andpharmaceuticals, power generation (including cogenera-tion), ship building, and the aerospace industry. Thebook is based on years of proven, successful practice,and almost all of the examples described are from pro-cess systems now in operation.

While practicality is probably its key asset, this secondvolume contains a unique collection of valuable informa-tion, such as a practical approach to bin and silo designas well as practical methods of controlling wind vibra-tions of stacks using vortex strakes; new information onnozzle loadings on compressors and turbines; compre-hensive discussions and examples on sizing pumps andcompressors for various process applications; expandedtube count tables for shell-andtube heat exchangers; apractical approach to design against tube bundle vibra-tion; and a comparative synopsis of the various nationalwind codes.

Topics included in the text are considered to be thosetypically encountered in engineering practice. For rea-sons of time and space the dynamic analyses of seismicresponse spectra and an extensive discussion on pulsa-tion response spectra in piping induced by acoustic pul-sation are not discussed. However, a short discussion isgiven on pulsation response spectra induced by acousticpulsations. Single-phase flow is much more common inmechanical systems than two-phase flow, so because oftime and space two-phase flow is not discussed.

This book is not intended to be a substitute or a re-placement of any accepted code or slandard. The readeris strongly encouraged to consult and be knowledgeable

Preface to Volume 2

of any accepted standard or code that may govern. It isfelt that this book is a valuable supplement to any stan-dard or code used.

The book is slanted toward the practices of the ASMEvessel and piping codes and the TEMA standard forshell-and-tube heat exchangers. The intent is not to beheavily prejudiced toward any standard, but to discussthe issue-engineering. If one feels that a certain stan-dard or code should be mentioned. olease remember thatlhere are olhe15 who may be using different standardsand it is impossible to discuss all of them.

The reader's academic level is assumed to be a bache-lor of science degree in mechanical engineering, but en-gineers with bachelor of science degrees in civil, chemi-cal, electrical, or other engineering disciplines shouldhave little difficulty with the book, provided, of course,that they have received adequate academic training orexpenence.

Junior or senior undergraduate engineering studentsshould find the book a useful introduction to the applica-tion of mechanical engineering to process systems. Pro-fessors should find the book a helpful reference (and a

source for potential exam problems), as well as a practi-cal textbook for junior-, senior-, or graduate-levelcourses in the mechanical, civil, or chemical engineeringfields. The book can also be used to supplement an intro-ductory level textbook.

The French philosopher Voltaire once said, "Commonsense is not very common," and unfortunately, this issomelimes the case in engineering. Common sense is of-ten the by-product of experience, and while both are es-sential to sound engineering practice, neither can beIearned from books alone. It is one ofthis book's soals to

tx

unite these three elements of "book learning," commonsense, and experience to give the novice a better grasp ofengineering principles and procedures, and serve as apractical design reference for the veteran engineer.

Finally, I wish to thank Dr. John J. McKetta, professorof chemical engineering at the University of Texas atAustin, who had many helpful comments, suggestions,and words of encouragement; other engineering faculty

members at the University of Texas at Austin for theircomments; Albert T. Taube, P.E., who was so kind tooffer helpful and useful comments while reviewingChapter 6; and John D. Guenther, P.E., for his helpfirlcritique of Chapter 7. Last, but certainly not least, I wishto express gratitude to William J. Lowe and Timothy W.Calk of Gulf Publishing Company whose hard work andpatience made this book possible.

A. Keith Escoe, P.E.