Steam Jet Ejectors for the Process Industries

521 Pages·049.97 MB·English

by  Robert B. Power

Steam Jet Ejectors

for the

Process Industries

i
Other Chemical & Mechanical Engineering Books of Interest

========= ( McGraw-Hill publisher unless otherwise noted ) ===============
BASTA + Shreve's Chemical Process Industries Handbook
BAUMEISTER ET AL + Mark’s Standard Handbook for Mechanical Engineers
CHOPEY + Environmental Engineering in the Process Plant
CHOPEY + Handbook of Chemical Engineering Calculations
COOK & DUMONT + Process Drying Practice
DILLON + Materials Selection for the Chemical Process Industries
FARAGALLAH + Liquid Ring Vacuum Pumps and Compresessors - GULF
FREEMAN + Standard Handbook of Hazardous Waste Treatment and Disposal
GRANT & GRANT + Grant & Hackh's Chemical Dictionary
HARRIS + Modern Vacuum Practice
KISTER + Distillation Design
KISTER + Distillation Operation
MANSFIELD + Engineering Design for Process Facilities
MANGNALL + Vacuum/Pressure Producing Machines and Associated Equipment -
HICK HARGREAVES & CO
MCGEE + Molecular Engineering
MILLER + Flow Measurement Handbook
PALLUZI + Pilot Plant Design, Construction, and Operation
PERRY & GREEN + Perry's Chemical Engineers' Handbook
REID ET AL + Properties of Gases and Liquids
REIST + Aerosol Science and Technology
RYANS & ROPER + Process Vacuum System Design and Operation
SANDLER & LUCKIEWICZ + Practical Process Engineering
SATTERFIELD + Heterogeneous Catalysis in Industrial Practice
SHINSKEY + Process Control Systems
SHUGAR & BALLINGER + The Chemical Technicians' Ready Reference Handbook
SHUGAR & DEAN + The Chemist's Ready Reference Handbook
SMITH & VAN LAAN + Piping and Pipe Support Systems
STOCK + AI in Process Control
TATTERSON + Fluid Mixing and Gas Dispersion in Agitated Tanks
TATTERSON + Scale-up of Industrial Mixing Processes
WILLIG + Environmental TQM

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Steam Jet Ejectors

for the

Process Industries

Robert B. Power

AUTHOR-PUBLISHER
381 Baker Ln
Charleston, WV 25302 USA
Tel / Fax [phone]
Website: www.jetwords.com

iii
Advance Book Information (ABI) data
Robert B. Power
Title: Steam Jet Ejectors for the Process Industries / Second Edition [3rd Printing (electronic) 2012]
ISBN : 0-9755706-4-1
ABI Number : 1249355

Copyright @ 2005 by Robert B. Power. All rights reserved. Printed in the United States of
America. Except as permitted under the United States Copyright Act of 1976, no part of this
publication may be reproduced or distributed in any form or by any means, or stored in a
data base or retrieval system, without the prior written permission of the publisher.
Second Edition, First Printing
Copyright 1994 by McGraw-Hill Inc. All rights reserved.
First Edition, Two Printings
The author converted the 2d edition of this book to digital format, reset it in Century
Schoolbook, and designed the new cover.
Printed and bound by C & M Press
Book Specifications:
522 pages
175 illustrations
147 line drawings
28 half-tones
17 tables
sewn binding
50# White Finch Opaque
Information contained in this work has been obtained by the author from sources believed
to be reliable. However, the author does not guarantee the accuracy or completeness of any
information published herein, and the author shall not be responsible for any errors,
omissions, or damages arising out of use of this information. This work is published with
the understanding that the author is supplying information but is not attempting to render
engineering or other professional services. If such services are required, the assistance of an
appropriate professional should be sought.

iv
with love

to my wife

JOAN MERING POWER with

whom I share

my bed and my planet. She

makes it all worthwhile.

P.S. We celebrated our 50th
wedding anniversary in 2002

v
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vi
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Contents

Preface xiii
Acknowledgments xvii

Chapter 1. How to Use This Book 1

1.1 In a Hurry
1
1.2 For Orientation Only 1
1.3 Organized to Match Your Priorities 1
1.4 Where to Invest Your Reading Time 3
3
1.5 Do It, Don't Just Read It!
4
1.6 Nomenclature
4
1.7 References

Part 1 Introduction to Ejectors 5

Chapter 2. What Is an Ejector? 7

2.1 Behavior of a Water Hose Jet 7
2.2 Adding a Mixing Tube 7
2.3 Improving the Mixing Tube 8
2.4 Basic Ejector Stage 9
2.5 Typical Steam Jet Air Ejector Stage 10
2.6 Variation of Velocity and Pressure in a Stage 11
2.7 Some "Cousins" in the Ejector Family 11
2.8 Ejectors versus Other Pumping Devices 23
2.9 Pressure Scales and Measurement 25
2.10 Temperature Scales 28
2.11 Thermodynamics 28
2.12 Fluid Statics and Dynamics 29
2.13 Condensers 29
2.14 Stage and Configuration Numbering and Naming Conventions 30
2.15 Evacuation / Steady Load, Single-Point versus Extended Curve 31

vii
viii Contents
2.16 Common QuestIons and Answers about Ejectors 31
2.17 Important Phases in the Life of an Ejector 32
2.18 General References to Ejector Systems 33
2.19 References 33
Part 2 Steam Jet Air Ejector Performance 35
Chapter 3. How Ejector Stages Behave 37
3.1 Testing an Ejector Stage 37
3.2 Some Last Stages Are Unstable at Low Loads 43
3.3 Making a Stage IntrinsIcally Unstable 43
3.4 Low-Compression-Ratio Stages 44
3.5 Multistage Ejectors 44
3.6 Unstable First Stage In a Series of Booster Stages 53
3.7 Summary 53
3.8 Nomenclature 54
3.9 References 55
Chapter 4. Stages: Engineering Calculations 57
4.1 OvervIew of Ejector-Stage Calculations 57
4.2 A Step-by-Step Approach to Stage Calculations 58
4.3 Selecting an Approach to Ejector Steam Usage Calculations 58
4.4 Derivation and Application of Calculation Methods 59
4.5 How a Liquid-Jet LiquId Ejector Works 60
4.6 How a Compressible Fluid Ejector Works 65
4.7 Surveying Analysis Methods 75
4.8 Empirical Performance Correlations 78
4.9 Dry Air Equivalent Gas Load 79
4.10 Stage Steam Usage 81
4.11 Stage Size Estimates 85
4.12 Multistage-EjectOr Steam and Water Usage 87
4.13 Priming / Hogging / Initial Evacuation 96
4.14 Performance Curve Shape 98
4.15 Nomenclature 102
4.16 References 103
Chapter 5. Condensers: Engineering Calculations 105
5.1 Overview of Condenser Calculations 105
5.2 Vapor-LiquId Equilibrium 108
5.3 Contact Condensers 122
5.4 Surface Condensers 125
5.5 Nomenclature 149
5.6 References 150
Contents ix

Chapter 6. Pressure Control 151

6.1 Overview of Pressure Control 151
6.2 System Curves 152
6.3 Process Condenser Noncondensables "Mask" Excess Area 179
6.4 Pressure Control Methods 180
6.5 Manual versus Automatic Control 193
194
6.6 Capacity Control
194
6.7 Control Steam and Water Flow for Economy
195
6.8 Nomenclature
196
6.9 References

Chapter 7. Installation 197

7.1 Overview 197
7.2 Process Piping 201
7.3 Stages 207
7.4 Condensers 212
7.5 Steam 213
215
7.6 Cooling Water
216
7.7 Condensate Removal Drains
224
7.8 Hotwells or Sealpots
226
7.9 Troubleshooting
227
7.10 Drainage
227
7.11 Safety
229
7.12 Nomenclature
229
7.13 References

Chapter 8. Operation, Testing, Troubleshooting, and 231
Maintenance

8.1 Overview 231
8.2 Operation 232
8.3 Testing 240
8.4 Troubleshooting 270
8.5 Maintenance 283
290
8.6 Nomenclature
290
8.7 References

Part 3 Specifying and Buying Steam Jet Ejectors 293

Chapter 9. Selecting a Vacuum Producer: Ejectors and/or 295
Mechanical Pumps

9.1 Overview 295
9.2 Vacuum Pump Features 296
x Contents

9.3 Feature Comparisons: Steam Jets versus Mechanical Pumps 303
9.4 Installed Costs, Operating Costs 309
9.5 Nomenclature 309
9.6 References 310

Chapter 10. Specifying and Buying Ejectors 311

10.1 Overview 311
10.2 Status of Process Design 319
10.3 Preparing the Ejector Specifications 323
10.4 Bid Evaluation 344
10.5 Shop Performance Testing 348
10.6 As-Built Performance and Construction Data 349
10.7 Nomenclature 349
10.8 References 349

Part 4 Other Ejector Applications and Upgrading 351

Ejector Usage

Chapter 11. Other Ejector Applications 353

11.1 Overview 353
11.2 Process Vacuum 353
11.3 Process, Miscellaneous 361
11.4 Steam-Jet Refrigeration 362
11.5 Steam-Jet and Gas-Jet Compressors 377
11.6 Liquid-Jet Liquid Ejector (Eductor) 389
11.7 Conveying Solids 394
11.8 Miscellaneous Utility Ejectors 394
11.9 Desuperheaters 395
11.10 Special Design Situations 395
11.11 Designing Your Own Systems 398
11.12 Nomenclature 401
11.13 References 402

Chapter 12. Upgrading Existing Ejector Procedures and 405
Hardware

12.1 Overview 405
12.2 Ejector Economics 409
12.3 Operating, Testing, and Troubleshooting 410
12.4 Maintenance 411
12.5 Design and Purchasing 411
12.6 Upgrading Vacuum Systems and Other Process Systems 412
12.7 Final Words of Encouragement, a Challenge for a Revolution 420
12.8 Nomenclature 421
12.9 References 421