Table Of ContentFlow Measurement
Flow
Measurement
Bela G. Liptak
EDITOR-IN-CHIEF
CRC Press
Taylor & Francis Group
Boca Raton London New York
CRC Press is an imprint of the
Taylor & Francis Group, an Informa business
To my colleagues, the process control and instrument engineers,
with the hope that they will make the world a better,
safer and happier place by applying the knowledge
found on these pages
Copyright © 1993 by Bela G. Liptak
All Rights Reserved
Published in Radnor, Pennsylvania 19089, by Chilton Book Company
No part of this book may be reproduced, transmitted or stored
in any form or by any means, electronic or mechanical,
without prior written permission from the publisher
Designed by Arlene Putterman
Manufactured in the United States of America
Library of Congress Cataloging-in-Publication Data
Flow measurement 1 Bela G. Liptak, editor-in-chief.
p. cm.
"An offprint book from the third edition of Instrument engineers'
handbook"—CIP data sheet.
Includes index.
ISBN 0-8019-8386-X (pbk.)
1. Process control—Equipment and supplies. 2. Flow meters.
I. Liptak, Bela G. U. Tide: Flow Measurement
TS 156.8.F646(cid:9) 1993
681'.2—dc20(cid:9) 92-56585
CIF
CONTENTS
GONTRIBLITOR S(cid:9) Ix 3
BTU FLOWMETERS FOR GASEOUS FUELS 19
INTRODUCTION xi Measuring Heat Flow(cid:9) 19
The BTU Flowmeter Loop 19
Applications 20
ORIENTATION TABLES 2
Conclusions 21
1
4
APPLICATION AND SELECTION 5
CROSS-CORRELATION FLOWMETERING 22
Meter Selection(cid:9) 5
Differential Pressure(cid:9) 5
5
Energy Costs 5
ELBOW TAPS 24
Orifice Plates(cid:9) 6
Venturi Tubes and Nozzles 6
6
Pitot Tubes(cid:9) 6
FLOW SWITCHES 26
Elbow Taps 6
Design Variations 27
Target (or Impact) Meters 7
Solids Flow Swtiches(cid:9) 28
Electromagnetic Flowmeters 7
Turbine Meters 7
7
Vortex Meters 7
JET DEFLECTION FLOW DETECTORS 30
Variable-Area Meters(cid:9) 7
Positive Displacement Meters 8 Hop-Tapping 31
Ultrasonic Meters(cid:9) 8 Conclusion 32
Metering Pumps 8
Mass Flowmeters 8(cid:9) 8
Cross-Correlation 9(cid:9) LAMINAR FLOWMETERS 33
Sonic Venturi 9(cid:9) Theory 34
Specialized Flowmeters 9(cid:9) Hagen-Poiseuille Law(cid:9) 34
Flowmeter Selection Procedure 9(cid:9) Design Parameters(cid:9) 34
Inaccuracy(cid:9) 14(cid:9) Design Calculations for Liquid Service(cid:9) 35
Reynolds Numbers(cid:9) 14(cid:9) Errors 35
Safety(cid:9) 15(cid:9) Range Extension Techniques 36
Installation(cid:9) 15(cid:9) Commercially Available Units(cid:9) 38
Cost 16(cid:9) Conclusions 38
2(cid:9) 9
BTU FLOWMETERS FOR NEAT(cid:9) MAGNETIC FLOWMETERS 39
EXCHANGERS 17(cid:9) Theory 39
Mechanical BTU Meters(cid:9) 18(cid:9) AC and DC Excitation 40
Electronic BTU Meters(cid:9) 18(cid:9) Dual-Frequency Excitation(cid:9) 41
vi(cid:9)Contents
Construction 41 13
Ceramic Liners 43 METERING PUMPS 73
Probe-Type Units 43 Peristaltic Pumps(cid:9) 74
Magmeter Electronics and Intelligence 45(cid:9) Piston Pumps 74
Capacity and Range 45 Diaphragm Pumps 75
Applications 45 Hydraulic-Actuated Metering Pumps 76
Installation 47 Pulsator-Head Pumps 77
Advantages 48 Proportioning Pumps 77
Limitations 49 Conclusions 78
10
MASS FLOWMETERS—CORIOLIS 50(cid:9) 14
ORIFICES 79
Theory 50
Head Meters 79
Construction 53
Theory of Head Meters 80
Sensor 53
Head Meter Characteristics(cid:9) 81
Electronics 56
Reynolds Number 81
Calibration 56
Compressible Fluid Flow 82
Zero Offset or Zero Stability 59
Choice of Differential Pressure Range 82
Inaccuracy 59
Pulsating Flow and Flow "Noise" 82
Fluid Properties 59
The Orifice Meter 83
Temperature 59
Flow Through the Orifice Plate 83
Density 59
Location of Pressure Taps 84
Pressure 59
Eccentric and Segmental Orifice Plates(cid:9) 85
Viscosity 60
60(cid:9) Quadra nt Edge and Conical Entrance Orifice
Pressure, Plugging, Erosion, Corrosion
Plates 86
Environmental Conditions 61
The Integral Orifice(cid:9) 87
Temperature 61
Installation 88
Humidity 61
Limitations 90
Vibration 61
Orifice Bore Calculations(cid:9) 91
Pipe Stress(cid:9) 61
Orifice Metering Accuracy 95
Installation 61
Applications 62
Advantages 62
Limitations 63 15
PITOT TUBES, AVERAGING AND DUCT SECTION
UNITS 97
11
Theory 97
MASS FLOWMETERS—MISCELLANEOUS 64
Static Pressure Measurement 98
Radiation-Type Mass Flowmeters 64
Single-Ported Pitot Tube 99
Angular-Momentum-Type Mass
Calibration of Pitot Tubes(cid:9) 100
Flowmeters 65
Multiple-Opening Pitot Tubes(cid:9) 100
Impeller-Turbine 65
Pressure Differential Produced(cid:9) 103
Constant-Torque-Hysteresis Clutch 66
Area-Averaging Pitat Stations(cid:9) 104
Twin-Turbine 66
Special Pitot Tubes for Pulsating Flow(cid:9) 105
Coriolis 66
Gyroscopic 67
Linear 67
Conclusions 67 16
POSITIVE DISPLACEMENT GAS
FLOWMETERS 107
12 The Diaphragm Meter 107
MASS FLOWMETERS—THERMAL 68 The Lobed Impeller 108
Heat Transfer Flowmeters 68 High-Precision Gas Flowmeter (cid:9)109
Bypass-Type Designs 70 Application Notes(cid:9) 109
Hot Wire Probes 71 Testing and Calibration(cid:9) 110
(cid:9)
Contents(cid:9)vii
17 23
POSITIVE DISPLACEMENT LIQUID METERS AND TURBINE AND OTHER ROTARY ELEMENT
PROVERS 111 FLOWMETERS 144
Nutating Disk(cid:9) 111 Liquid Turbine Meters(cid:9) 145
Rotating Vane(cid:9) 112 Electronic Display Units(cid:9) 145
(cid:9)
Oscillating Piston(cid:9) 112 Linearity and Repeatability 146
(cid:9)
Reciprocating Piston(cid:9) 113 Viscosity and Density Effects 147
Rotating Lobe and Impeller 113(cid:9) Meter Sizing(cid:9) 147
(cid:9)
Oval-Gear Flowmeters(cid:9) 114 Felton Wheel Meters 149
Viscous Helix(cid:9) 114 Meter Characteristics and Features(cid:9) 149
High-Precision Displacement Flowmeter 5(cid:9) Me chanical Installation(cid:9) 150
Accessories and Intelligent Electronics 115(cid:9) E lectrical Installation(cid:9) 151
Provers 115 Gas Turbine Meters(cid:9) 151
Positive Desplacement Flowmeter Impeller and Shunt Flowmeters(cid:9) 152
Summary 116 Insertion-type Flowmeters(cid:9) 153
Optical Flow Sensors(cid:9) 154
Paddlewheel Flowmeters(cid:9) 154
18
PURGE FLOW REGULATORS 118
24
Purge Rotameters(cid:9) [18
ULTRASONIC FLOWMETERS 155
Transit-Time Flowmeters(cid:9) 156
19
Frequency Difference-type(cid:9) 156
SEGMENTAL WEDGE FLOWMETER 121
Flowmeter Construction(cid:9) 157
Application and Performance(cid:9) 158
20
Doppler Flowmeters(cid:9) 158
SIGHT FLOW INDICATORS 124
Application and Performance(cid:9) 159
Displays, Receivers, and Intelligent Units(cid:9) 159
21
SOLIDS FLOWMETERS AND FEEDERS 127
25
Hoppers and Their Accessories(cid:9) 128 VARIABLE-AREA GAP, AND VANE
Throttling the Flow to the Feeders(cid:9) 129 FLOWMETERS 162
Vertical Gate(cid:9) 129
Rotameters 163
Rotary Vane 130
Sizing 164
Screw Feeder(cid:9) 130
Rotameter Characteristics(cid:9) 164
Vibratory Feeder (cid:9)131
Rotameter Types(cid:9) 165
Shaker Feeder(cid:9) 131
Bypass and Pitot Rotameters(cid:9) 166
Roll Feeder (cid:9)131
Tapered Plug and Piston Meters(cid:9) 167
Revolving Plate Feeder (cid:9)132
Gates and Vanes(cid:9) 167
Belt Feeders(cid:9) 132
Feed Rate Control(cid:9) 133
26
Belt Speed Control(cid:9) 134
V-CON E FLOWMETER 170
Digital Control(cid:9) 135
Vertical Gravimetric Feeder (cid:9)136
Nuclear Belt Scales(cid:9) 137
27
Loss-in-Weight Flowmeters(cid:9) 137
VENTURI TUBES, FLOW TUBES, AND FLOW
Equipment 138 NOZZLES 172
System Sizing(cid:9) 138
The Classic Venturi(cid:9) 173
Dual-Chamber Gravimetric Feeder (cid:9)139
Short-Form Venturis(cid:9) 173
Dynamic Solids Flowmeters(cid:9) I39
Installation(cid:9) 174
Impulse-type Solids Flowmeters(cid:9) 139
Flow Calculations(cid:9) 175
Accelerator-type Flowmeter (cid:9)140
Flow Tubes 175
Volumetric Flowmeters(cid:9) 141
Flow Nozzles(cid:9) 176
Application Considerations(cid:9) 178
22(cid:9) Critical-Velocity Venturi Nozzles(cid:9) 178
TARGET METERS 142 Accuracy 178
viii (cid:9)Contents
Differential Pressure Measurement (cid:9)179 29
Conclusions 179 WEIRS AND FLUMES 192
Weirs 192
28 The Parshall Flume(cid:9) 194
VORTEX AND FLUIDIC FLOWMETERS 181 The Palmer Bowlus Flume(cid:9) 195
The Kennison Nozzle, Parabolic Flume, and
The Vortex Shedding Phenomenon 182
Leopold Lagco Flume 195
The Detector (cid:9)182
Detectors for Open-Channel Sensors(cid:9) 196
Features 184
Selection and Sizing(cid:9) 184
Installation Requirements(cid:9) 188 A.1 INTERNATIONAL SYSTEM OF UNITS 197
Vortex Precession (Swirl) Meters(cid:9) 188
Fluidic (Coanda Effect) Meter (cid:9)189
A.2 ENGINEERING CONVERSION FACTORS 198
Characteristics 189
Oscillating Vane in Orifice Bypass(cid:9) 190
Conclusions 191 INDEX 208
CONTRIBUTORS
CATHY APPLE(cid:9) BSChE, Project Engineer, Micro Motion Inc.
JAMES B. ARANT(cid:9) BS ChE, Senior Consultant, E.I. du Pont de Nemours Co.
GILES M. CRABTREE(cid:9) BSEE , PE, Principal Engineer. GIMACA Engineering
LOUIS D. DINAPOU(cid:9) BSE E, MSEE, Director. Flowmeter Marketing and Technology, B1F Products of Leeds &
Northrup Co.
ALBERT P. FOUNDOS(cid:9) BSCh E. MBA, President, Fluid Data Inc.
JOEL 0. HOUGHEN(cid:9) PhD ChE, PE. Consultant, Professor Emeritus, University of Texas
WILFRED H. HOWE(cid:9) BSE E, MBA, PE, Chief Engineer, The Foxboro Co.
DAVID S. KAYSER(cid:9) BS EE, Senior Instrument Engineer, Texas City Refining Inc.
JOHN G. KOPP(cid:9) BSME, PE, Senior Product Marketing Manager, Fischer & Porter Co.
BELA G. UPTAK(cid:9) M E, MME, FE, President, Liptak Associates P.C.
DAVID J. LOMAS(cid:9) M arketing Support Executive, Kent Process Control Ltd.
DAVID C. HAIR(cid:9) B CE, PE, Manager. Sales Services, Wallace & Tiernan Div. of Pennwalt Corp_
KURT 0. PLACHE(cid:9) BS ChE, PE, Vice-President, Marketing, Micro-Motion Inc.
MICHAL PTACHIK(cid:9) Ph D, Aeronautical Research and Test Institute, Czechoslovakia
STEPHAN RUDBACH(cid:9) MSc, President, Matematica AB, SWEDEN
ROBERT S/EV(cid:9) BSChE, MBA, CE, Engineering Specialist, Bechtel Corp.
JOAN B. STODDARD(cid:9) PhD, President. Stoddard Productivity Systems Inc.
EUGENE L SAINNTAGH MSChE, PhD, PE. Consultant
ix
