Boiler Operator’s Handbook

415 Pages·2006·10.07 MB·English

Boiler Operator’s Handbook
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Boiler Operator’s Handbook
By
Kenneth E. Heselton, PE, CEM
THE FAIRMONT PRESS, INC. MARCEL DEKKER, INC.
Lilburn, Georgia New York and Basel
iii
Library of Congress Cataloging-in-Publication Data
Heselton, Kenneth E., 1943-
Boiler operator's handbook / by Kenneth E. Heselton
p. cm.
Includes index.
ISBN 0-88173-434-9 (print) -- ISBN 0-88173-435-7 (electronic)
1. Steam-boilers--Handbooks, manuals, etc. I. Title.
TJ289.H53 2004
621.1'94--dc22
2004053290
Boiler operator's handbook / by Kenneth E. Heselton
©2005 by The Fairmont Press, Inc. All rights reserved. No part of this publication
may be reproduced or transmitted in any form or by any means, electronic or
mechanical, including photocopy, recording, or any information storage and re-
trieval system, without permission in writing from the publisher.
Published by the Fairmont Press, Inc.
700 Indian Trail
Lilburn, GA 30047
tel: [phone]; fax: [phone]
http://www.fairmontpress.com
Distributed by Marcel Dekker, Inc.
270 Madison Avenue, New NY 10016
tel: [phone]; fax: [phone]
http://www.dekker.com
Printed in the United States of America
10 9 8 7 6 5 4 3 2 1
0-88173-434-9 (The Fairmont Press, Inc.
0-8247-4290-7 (Marcel Dekker, Inc.)
While every effort is made to provide dependable information, the publisher,
authors, and editors cannot be held responsible for any errors or omissions.
iv
Table of Contents
Chapter 1 - OPERATING WISELY..............................................1 Waste heat service............................................................123
Why wisely?..........................................................................1
Prioritizing.............................................................................1 Chapter 5 - MAINTENANCE..................................................125
Safety.......................................................................................5 Maintenance.......................................................................125
Measurements .......................................................................7 Cleaning .............................................................................126
Flow ......................................................................................13 Instructions and specifications.......................................127
What happens naturally ...................................................14 Lock-out, tag-out..............................................................128
Water, steam and energy ..................................................15 Lubrication.........................................................................129
Combustion..........................................................................18 Insulation ...........................................................................132
The central boiler plant.....................................................25 Refractory...........................................................................134
Electricity..............................................................................26 Packing...............................................................................136
Documentation....................................................................31 Controls and instrumentation........................................138
Standard Operating Procedures ......................................33 Lighting and electrical equipment................................140
Disaster Plans......................................................................36 Miscellaneous....................................................................143
Logs.......................................................................................37 Replacements.....................................................................144
Maintaining efficiency.....................................................148
Chapter 2 - OPERATIONS..........................................................45 Records...............................................................................149
Operating Modes................................................................45
Chapter 6 - CONSUMABLES...................................................151
Valve manipulation............................................................45
Fuels....................................................................................151
New startup.........................................................................49
Fuel gases...........................................................................152
Dead plant startup.............................................................62
Oils......................................................................................154
Normal boiler startup........................................................63
Coal.....................................................................................159
Emergency boiler startup..................................................65
Other solid fuels...............................................................160
Normal operation...............................................................67
Water...................................................................................162
Idle equipment....................................................................69
Treatment chemicals.........................................................164
Superheating........................................................................72
Miscellaneous....................................................................165
Switching fuels....................................................................73
Standby operation..............................................................75
Chapter 7 - WATER TREATMENT .........................................167
Rotating (alternating) boilers...........................................76
Water treatment................................................................167
Bottom blowoff...................................................................77
Water testing......................................................................168
Annual inspection..............................................................78
Pretreatment ......................................................................172
Operating during maintenance and repairs..................80
Feedwater tanks and deaerators...................................175
Pressure testing...................................................................81
Blowdown..........................................................................179
Lay-up...................................................................................83
Chemical treatment..........................................................180
Tune-ups...............................................................................84
Preventing corrosion........................................................182
Auxiliary turbines..............................................................88
Preventing scale formation.............................................184
Chapter 3 - WHAT THE WISE OPERATOR KNOWS..........93
Chapter 8 - STRENGTH OF MATERIALS ............................187
Know your load .................................................................93
Strength of materials .......................................................187
Know your plant................................................................97
Stress...................................................................................187
Matching equipment to the load ....................................98
Cylinders under internal pressure................................189
Efficiency............................................................................100
Cylinders under external pressure................................191
Performance monitoring.................................................105
Piping Flexibility ..............................................................192
Modernizing and upgrading..........................................106
Chapter 9 - PLANTS AND EQUIPMENT.............................195
Chapter 4 - SPECIAL SYSTEMS..............................................109 Types of Boiler Plants......................................................195
Vacuum systems...............................................................109 Boilers.................................................................................196
Hydronic heating..............................................................110 Heat transfer in boilers...................................................197
High temperature hot water (HTHW).........................114 Circulation..........................................................................199
Organic fluid heaters and vaporizers ..........................116 Construction......................................................................202
Service water heating......................................................118 Boiler, cast iron and tubeless.........................................203
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Firetube boilers.................................................................203 Instrumentation.................................................................340
Watertube boilers..............................................................208
Trim.....................................................................................219 Chapter 11 - WHY THEY FAIL
Heat traps..........................................................................231 A little bit of history........................................................347
Burners ...............................................................................234 Low water..........................................................................347
Pumps.................................................................................249 Thermal Shock..................................................................349
Fans and blowers.............................................................268 Corrosion and wear.........................................................350
Cogeneration .....................................................................280 Operator error and poor maintenance.........................350
Chapter 10 - CONTROLS APPENDICES
The basics...........................................................................289 Properties of water and steam ......................................353
Self contained controls....................................................305 Water pressure per foot head........................................357
Linearity.............................................................................307 Nominal capacities of pipe.............................................358
Steam pressure maintenance..........................................308 Properties of pipe.............................................................360
Fluid temperature maintenance.....................................312 Secondary ratings of joints,
Fluid level maintenance..................................................314 flanges, valves, and fittings.................................368
Burner management.........................................................318 Pressure ratings for various pipe materials................371
Firing rate control ............................................................321 Square root curve.............................................................372
Low fire start.....................................................................322 Square root graph paper.................................................373
High-Low...........................................................................322 Viscosity conversions.......................................................374
Burner cutout....................................................................323 Thermal expansion of materials....................................376
Jackshaft control ...............................................................323 Value conversions.............................................................377
Establishing linearity.......................................................326 Combustion calculation sheets ......................................378
Startup control..................................................................327 Excess air/O curve.........................................................384
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Parallel positioning..........................................................328 Properties of Dowtherm A.............................................385
Inferential metering..........................................................330 Properties of Dowtherm J...............................................386
Steam flow / air flow.....................................................330 Chemical Tank Mixing Table .........................................387
Full metering cross limited ............................................331 Suggested mnemonic abbreviations for
Dual fuel firing.................................................................333 device identification..............................................389
Choice fuel firing..............................................................334 Specific heats of common substances ..........................391
Oxygen trim ......................................................................334 Design temperatures for selected cities.......................392
Combustibles trim............................................................336 Code Symbol Stamps.......................................................395
Draft control......................................................................336 Bibliography.................................................................................396
Feedwater pressure control............................................338 Index .............................................................................................397
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Introduction
This book is written for the boiler operator, an out, and one of the best ways of knowing it is to get into
operating engineer or stationary engineer by title, who it. The operator should be able to do the work or super-
has knowledge and experience with operating boilers vise it. Only by knowing what it’s like inside can the
but would like to know more and be able to operate his operator make sound judgments when operating situa-
plant wisely. It is also simple enough to help a beginning tions become critical.
operator learn the tricks of the trade by reading the book As for keeping an eye on the plant, that phrase is
instead of learning the old-fashioned way (through ex- nothing more than a saying. If you are a manager, read-
perience) some of which can be very disagreeable. The ing this book because operators report to you, you
book can also be used by the manager or superintendent should know this—the experienced operator keeps an
who wants a reference to understand what his operators ear on the plant. The most accurate, precise, sensitive
are talking about. It’s only fair, however, to warn a instrument in a boiler plant is the operator’s ear. The
reader of this book that it assumes a certain amount of operator knows something is amiss long before any
experience and knowledge already exists. alarm goes off because he can hear any subtle change in
The day I mailed the contract for this book to the the sound of the plant. He can be up in the fidley, and
publisher I sat across a table from a boiler operator who notice that a pump on the plant’s lower level just shut
said, “Why hasn’t somebody written a book for boiler down. Hearing isn’t the only sense that’s more acute in
operators that isn’t written for engineers?” I’ve tried to an operator, he “feels” the plant as well. Sounds, actually
do it with this book, no high powered math and minimal all sound is vibrations, that aren’t in the normal range of
technical jargon. hearing are sensed either by the ear, the cheek, or
There are two basic types of operators, those that through the feet. Certainly an operator shouldn’t be in-
put in their eight hours on shift while doing as little as side a boiler turbining tubes, while he’s operating the
possible and those that are proud of their profession and plant but there are many maintenance activities he can
do their best to keep their plant in top shape and run- perform while on duty. Managers with a sense of the
ning order. You must be one of the latter and you should skill of their operators will use them on overtime and
take pride in that alone. off-shift to perform most of the regular maintenance.
There is a standard argument that operators oper- Chapter 1, “Operating Wisely,” is the guiding out-
ate; they don’t perform maintenance duties or repair line for an operator that wants to do just that. The rest of
anything because they have to keep their eye on the the book is reference and informational material that
plant. That’s hogwash. As an engineer with more than either explains a concept of operation or maintenance in
forty-five years experience in operating and maintaining greater detail, or offers definitions.
boiler plants, I know an operator can’t allow someone I hope this book gives you everything you need to
else to maintain and repair his equipment. It’s impera- operate wisely. If it doesn’t, call me at 410-679-6419 or e-
tive that the operator know his equipment, inside and mail [email protected].
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Operating Wisely 1
Chapter 1
Operating Wisely
IIIII
f it were not for the power of the human mind with waste of time, some did more harm than good, and oth-
its ability to process information and produce concepts ers were downright dangerous. Most of those actions
that have never existed before we would be limited to could be traced to instructions for situations that no
living out our lives like the other species that reside on longer exist or to a misunderstanding by the operator of
this earth. We would act as we always have and never what was going on. To learn to operate wisely you have
make any progress or improve our lives and our envi- to know why you do things and what happens when
ronment. you do the wrong thing. This book tries to cover both.
We could, of course, do only those things expected When you understand why you do things you’re more
of us and be content with the rewards for doing so. Read likely to do them correctly.
on if you’re not contented with simply being and doing. When you have an opportunity to make a mistake,
it’s always nice to know how someone else screwed up.
As Sam Levenson once said, “You must learn from the
WHY WISELY? mistakes of others. You can’t possibly live long enough
to make them all yourself.” Many mistakes are described
Actually I intended the title of this book to be in the following pages so you will, hopefully, not repeat
“Operating Wisely” because there are many books with them.
the title of “Boiler Operator’s Handbook” available to- Two other reasons for this book are the environ-
day. Some are small, some are large, and all have good ment and economics. If every boiler operator applied a
information in them. If you don’t already have one or few of the wise actions described in this book there
two, I’m surprised. This isn’t just another boiler would be a huge reduction in energy consumption and,
operator’s handbook. However, the publisher wanted to as a result, a dramatic improvement in our environment.
call it a boiler operator’s handbook to be certain its con- You can earn your salary by proper operation that keeps
tent was properly described. Those other books describe fuel, electricity, and water costs as low as possible while
the plant and equipment but don’t really talk about still providing the necessary heat to the building and
operating, and in many cases they fail to explain why processes. Wise people don’t do damage to their envi-
you should do certain things and why you shouldn’t do ronment or waste the boss’ money. I hope to give you all
others. the wisdom I gained over forty-five years in this busi-
It’s said that “any automatic control will revert to ness so you can operate wisely.
the level of competence of the operator.”1 It’s clear that
engineers can design all sorts of neat gadgets but they
won’t work any better than the operator allows. What PRIORITIZING
they always seem to miss is the fact that they never told
the operator what the gadget was supposed to do and The first step in operating wisely is to get your pri-
how to make sure it does it. Lacking that information, orities in order. Imagine taking a poll of all the boiler
the operator reverts to a strategy that keeps the plant plant operators you know and asking them what is the
running. Hopefully this book will provide you with a most important thing they have to do. What would they
way to figure out what the engineer was trying to ac- list first? I’m always getting the reply that it’s keeping
complish so you can make the gadget work if it does do the steam pressure up, or something along those lines.
a better job. In some cases you’re right, the darn thing is Why? The answer is rather simple; in most cases, the
a waste of time and effort, but hopefully you won’t dis- only time an operator hears from the boss is when the
miss them out of hand anymore. New gadgets and pressure is lost or everyone is complaining about the
methods are tools you can put to use. cold or lost production. Keep the pressure up and you
Over the years I’ve observed operators doing a lot will not have any complaints to deal with, so it gets first
of things that I considered unwise; some were simply a billing. Right? … Wrong!
1
2 Boiler Operator’s Handbook
History is replete with stories of boiler operators else gets hurt. The operator that risks his life to save a
doing stupid things because their first priority was con- friend that committed a stupid act is not a hero. He’s
tinued operation. There are the operators that literally another fool. Abandoning responsibility to maintain con-
held down old lever acting safety valves to get steam trol of a situation and risking your life is getting your
pressure higher so their boat would beat another in a priorities out of order. While preventing or minimizing
race. Many didn’t live to tell about it. I recall a chief injury to someone else is important, it is not as impor-
engineer aboard the steamship African Glade instructing tant as protecting you.
me to hit a safety valve with a hammer when he sig- Other people should follow you on your list of
naled me; so the safety would pop at the right pressure. priorities. There are occasions when the life or well being
The object was to convince the Coast Guard inspector of other people is dependent on a boiler operator’s ac-
that the safety valve opened when it was supposed to. A tions. There are many stories of cold winters in the north
close look at that safety valve told me that hitting it with where operators kept their plants going through unusual
a hammer was a dumb thing to do. Thankfully the valve means to keep a population from freezing. A favorite
opened at the right pressure of its own accord. That was one is the school serving as a shelter when gas service
an example of self endangerment to achieve a purpose was cut off to a community. When the operator ran out
that, quite simply, was not worth risking my life. of oil, he started burning the furniture to keep heat up.
It’s regrettable that keeping pressure up is the pri- That form of ingenuity comes from the skill, knowledge
ority of many operators. Several of them now sit along- and experience that belongs to a boiler operator and al-
side Saint Peter because they were influenced by the lows him to help other people.
typical plant manager or others and put the wrong Next in the proper list of priorities is the equip-
things at the top of their list of priorities. Another opera- ment and facilities. Keeping the pressure up is not as
tor followed his chief’s instructions to hit a safety valve important as preventing damage to the equipment or the
so it would pop several years ago. The valve cracked building. A short term outage to correct a problem is less
and ruptured, relieving the operator of his head. With- disrupting and easier to manage. It’s better than a long
out a doubt the superintendents and plant managers term outage because a boiler or other piece of equipment
that demanded their now dead operators blindly meet was run to destruction. The wise operator doesn’t permit
selected objectives are still asking themselves why they continued operation of a piece of equipment that is fail-
contributed to their operator having the wrong impres- ing. Plant operations might be halted for a day or week
sion. Despite how it may seem, your boss doesn’t want while parts are manufactured or the equipment is over-
you risking your life to keep the pressure up; he just hauled. That is preferable to running it until it fails—
loses sight of the priorities. The wise operator doesn’t then waiting nine months to obtain a replacement. You
list pressure maintenance or other events as having pri- can counter complaints from fellow employees that a
ority over his safety. week’s layoff is better than nine months. There are sev-
So what is at the top of the list? You are, of course. eral elements of operating wisely that consider the prior-
An operator’s top priority should always be his own ity of the equipment.
safety. Despite the desire to be a hero, your safety should Many operators choose to bypass an operating
take priority over the health and well being of other limit to keep the boiler on line and avoid complaints
people. It simply makes sense. A boiler plant is attended about pressure loss. Even worse, they bypass the limit
by a boiler operator to keep it in a safe and reliable because it was a nuisance. “That thing is always tripping
operating condition. If the operator is injured, or worse, the boiler off line so I fixed it.” The result of that fix is
he or she can’t control the plant to prevent it becoming frequently a major boiler failure. Operator error and
a hazard to other people. improper maintenance account for more than 34% of
For several years a major industrial facility near boiler failures.
Baltimore had an annual occurrence. An employee en- The environment has taken a new position on the
tered a storage tank without using proper entry proce- operator’s list of priorities within the last half century.
dures and subsequently succumbed to fumes or lack of Reasons are not only philanthropic but also economic.
oxygen. Now that’s bad enough, but… invariably his Regularly during the summer, the notices advise us that
buddy would go into the tank in a failed effort to re- the air quality is marginal. Sources of quality water are
move him, and they both died. Rushing to rescue a fool dwindling dramatically. The wrong perception in the
is neither heroic nor the right thing to do; calling 911 minds of the company’s customers can reduce revenue
then maintaining control of the situation is; so nobody (in addition to the costs of a cleanup) and the combina-