Wet Scrubbers

225 Pages·1996·20.565 MB·English

by  Kenneth C. Schifftner, Howard D. Hesketh

WET SCRUBBERS

W ì
fCermetli C. Schffftner, BSMi
Technical Director, Compliance Systems International
How ard E« Hesicetli, Ph.D., P
Professor Emeritus, Southern Illinois University
Taylor &. Francis
Taylor &. Francis Group
Boca Raton London New York
CRC is an imprint of the Taylor & Francis Group,
an informa business
Published in 1996 by
CRC Press
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© 1996 by Taylor & Francis Group, LLC
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Printed in the United States of America on acid-free paper
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International Standard Book Number-10: 1-56676-379-7 (Softcover)
International Standard Book Number-13: 978-1-56676-379-0 (Softcover)
Library of Congress catalog number: 95-62014
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TABLE OF CONTENTS
Preface vii
Preface to the First Edition IX
Acknowledgements xi
Introduction xiii
Nomenclature xv
Chapter 1. Application Engineering Basics
1.1 Introduction 1
1.2 Scrubber Types 4
1.3 Basic Calculations 10
1.4 Particulate Scrubbers Available 30
1.5 Absorber Calculations 47
1.6 Mist Elimination 54
1.7 Additional Suggested Reading 61
1.8 References 64
Chapter 2. Fiberbed Filters and Wet Scrubbing . . . .67
2.1 Collection by Direct Interception 71
2.2 Collection by Inertial Interception 72
2.3 Collection by Brownian Motion of Particles 72
2.4 Pressure Drop 76
2.5 Reentrainment 80
2.6 References 85
VI Table of Contents
Chapter 3. Scrubber Applications ............ .87
3„1 Introduction 87
3.2 Asphalt Plant Scrubbers 87
3.3 Bark Boiler Scrubbers 92
3.4 Foundry Cupola Scrubbers (Ferrous Metals) 100
3.5 Lime Kiln Scrubbers 104
3.6 Municipal Sledge Incinerator Scrubbers 115
3.7 Sewage Sledge Dryer Scrubbers 120
3.8 Industrial Boiler Scrubbers 129
3.9 Odor Control Scrubbers 141
3.10 Hybrid Scrubbers 148
3.11 Waste Minimization Using Wet
Scrubbing Techniques 162
3.12 References 173
Chapter 4« Maintenance and Control 175
4.1 Introduction 175
4.2 Optimization 175
4.3 System Characteristics 179
4.4 Chemical Control 180
4.5 Other Instrumentation 181
4.6 Personnel 181
4.7 Checklists 181
4.8 References 184
Chapter 5. Testing Wet Scrubbers . . . 185
5.1 Introduction 185
5.2 Dry Flue Gas Composition 185
5.3 Diagnostic Testing 186
5.4 Compliance Testing 190
5.5 References 192
Chapter 6. Suggested Readings .........................................193
Index 199
About the Authors 205
PREFACE
Welcome to the second edition of Wet Scrubbers.
It hardly seems that it was more than a decade ago that Dr. Howard
Hesketh and I wrote the first edition of Wet Scrubbers. The purpose then
was to provide an easy-to-read, easy-to-understand technical book on the
design and application of gas cleaning technologies that use liquids. The
original edition found its way onto the reference shelves of plant engineers,
environmental engineers, regulatory personnel, and others who spend all
or part of their time studying and/or solving air pollution problems. It has
also been added to many libraries as a useful reference tool for students and
others interested in pollution control. We have been very pleased to hear
many favorable comments from those individuals who use Wet Scrubbers as
a reference.
Our purpose in providing this second edition is to build upon that base
and update a number of chapters to reflect the exciting changes that have oc­
curred in the industry during the last decade. We have added to the theory
of operation of wet scrubbers, included a section on new ‘‘hybrid” scrubber
systems that use multiple control techniques, and added a section on ir­
rigated fiberbed filters that utilize Brownian motion capture techniques for
fine aerosol capture.
During the last decade, regulatory codes have become increasingly strin­
gent, prompting designers to seek either better performance for their ex­
isting control equipment or to add new equipment of higher efficiency.
Technology to control specific pollutants such as mercury compounds,
hexavalent chrome, and dioxins have all been “developed” in the last decade
in response to real or perceived needs to control these pollutants. Some of
the processes “developed,” such as flux force condensation scrubbing, were
in actuality rediscovered. Coupled with cost constraints, the challenge
VII
VIII Preface
facing personnel confronted with environmental compliance can appear
daunting. A careful review of the technologies available, however, can lead
to successful completion of such projects.
It can be said that air pollution control is a mixture of control technology,
economics, health sciences, safety considerations, plant design, law, statis­
tics, judgment, and, yes, beliefs. The air pollution control engineering en­
vironment, we feel, is regulatory-driven, based upon the popular belief that
the public health should be protected at a reasonable cost. It is based upon
the concept that, when we derive benefit from Nature, we should not de­
stroy Nature in the process. Some say this effort should be tempered by ap­
plying “cost/benefit analysis” to these health issues. The response is that we
already do. The marketplace performs a cost/benefit analysis when an indi­
vidual or company selects a specific pollution control technology to use. It
can be further argued, “What is the dollar value of a human life?” Is it not
priceless? The air pollution control industry reacts by agreeing that human
life is indeed priceless, but one should not have to go bankrupt to protect it.
Choosing the appropriate system and operating it properly goes a long
way in this regard, and thousands of air pollution control systems in suc­
cessful operation around the world are testament to the fact that one can
protect the public health without excessive cost. In addition, pollution con­
trol engineers work daily to reduce the operating cost of control equipment.
New products continually arrive on the scene offering efficiency improve­
ments at reduced cost. Older, less efficient, more costly systems fade away.
This second edition of Wet Scrubbers will help personnel who are in­
volved with air pollution control issues make important decisions regarding
how pollution can be reduced in an economical manner and feel confident
that they have made the proper decision. The contents of this book are in­
tended to supplement other information the readers may have about the
problem and to reach an educated conclusion about the best course of ac­
tion.
PREFACE TO THE FIRST EDITION
The application of wet scrubbers to industrial sources is both an art and
a science. The science is called “applications engineering.” The art is called
“experience.”
In this monograph, we provide information of sufficient detail to permit
plant engineers and those interested in air pollution control to select and
properly apply commercially available technology, combining art with sci­
ence. To make this task easier, we have endeavored to present basic back­
ground information, as well as specific examples, in a concise manner.
Each application section is summarized by an Applications Guide. These
guides contain general information regarding each specific application, in­
cluding expected pressure drops, types of equipment, possible trouble
areas, items to avoid and design specifics.
We do not pretend to present the only “right way”; there are various
means to the same end when it comes to air pollution control. Our examples
are based on successful installations, with information contributed as much
by those people and firms who use the equipment as by those who designed
the systems. The use of equipment exposes its advantages and pitfalls
beyond the picture painted by the salesman, his brochures or the company
he represents. Use alone shows whether the design is proper for the applica­
tion. Use reflects the true cost of an air pollution control system, not merely
the initial cost. Proper use is the successful blending of application en­
gineering science and the art of experience.
Kenneth C. Schifftner
Howard E. Hesketh
IX