Steam plant operation; seventh edition

Steam Plant Operation Everett B Woodruff Herbert B Lammers Thomas F Lammers Seventh Edition McGraw-Hili New York San Francisco Washington, D.C Auckland Bogota Caracas Lisbon London Madrid Mexico City Milan Montreal New Deihl San Juan Singapore Sydney Tokyo Toronto Library of Congress Cataloging-in-Publication Data Lammers, Thomas F Steam plant operation / Thomas F Lammers.-7th ed p em First-fourth eds by E B Woodruff and H B Lammers Fifth ed by E B Woodruff and T F Lammers Sixth ed by T F Lammers Includes index ISBN 0-07-036150-9 (alk pape~) Steam power plants.-I Woodruff, Everett B (Everett Bowman), 1900-1982 -II Lammers, Herbert B 1902-1981 1900-1982 Steam-plant operation II Title TJ405.L36 1998 621.1-dc21 97-460156 CIP 'iZ McGraw-Hill A Division of TheMcGraw-HiU Companies Copyright © 1998,1992,1984,1977,1967,1950,1935 by The McGrawHill Companies, Inc 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 DOC/DOC ISBN 0-07-036150-9 The sponsoring editors for this book were Hal Crawford and Robert Esposito, the editing supervisor was Ruth w: Mannino, and the production supervisor was Pamela Pelton It was set in Century Schoolbook by Dina John of McGraw-Hilt's New York desktop publishing department Printed and bound by R R Donneltey and Sons Company McGraw-Hill books are available at special quantity discounts to use as premiums and sales promotions, or for use in corporate training programs For more information, please write to the Director of Special Sales, McGraw-Hill, Professional Publishing, Two Penn Plaza, New York, NY 10121-2298 Or contact your local bookstore Contents Preface Chapter xl Steam and Its Importance The Use of Steam The Steam-Plant Cycle The Power Plant Utility Boilers for Electric Power 1.4.1 Coal-Fired Boilers 1.4.2 011 and Gas-Fired Boilers 1.4.3 Steam Considerations 1.4.4 Boller Feedwater 1.5 Industrial and Small Power Plants 1.5.1 Fluidized Bed Boilers 1.5.2 Combined Cycle and Cogeneration Systems 1.6 Summary Questions and Problems 1.1 1.2 1.3 1.4 Chapter Boilers 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 2.9 2.10 The Boller Fundamentals of Steam Generation 2.2.1 Boiling 2.2.2 Circulation 2.2.3 Steam-Water Separation Fire-Tube Boilers Water-Tube Boilers Steam-Water Separation Principles of Heat Transfer Superheaters Superheat Steam Temperature Control 2.8.1 Attemperatlon 2.8.2 Flue Gas Bypass 2.8.3 Flue Gas Recirculation Heat-Recovery Equipment Furnace Design Considerations 11 12 15 15 15 18 21 24 24 27 27 29 29 30 32 32 38 49 53 54 57 58 59 59 60 67 viii Contents Contents 2.11 2.12 2.13 Furnace Construction Industrial and Utility Boilers Considerations for Coal Firing 2.13.1 Spreader Stokers 2.13.2 Pulverized-Coal Firing 2.13.3 Stoker versus Pulverized-Coal Firing 2.14 Pressurized versus Balanced-Draft Boller Designs 2.15 Fluidized Bed Boilers 2.15.1 The Process 2.15.2 Comparison with Pulverized-Coal and Stoker Firing 2.15.3 Advantages of Fluidized Bed Combustion 2.15.4 Descriptions of Fluidized Bed Boilers 2.15.5 Emissions Control with Fluidized Bed Boilers 2.15.6 Bed Material 2.15.7 Heat Transfer 2.16 Modern Coal-Fired Plants-Summary 2.17 Process Steam and Its Application 2.18 Combined Cycle and Cogeneration Systems 2.19 Nuclear Steam Generation Questions and Problems Chapter Design and Construction of Boilers 129 3.1 Materials Used in Boller Construction 3.2 Stresses in Tubes, Boller Shells, and Drums 3.3 Drum and Shell Construction 3.4 Welded Construction 3.5 Structural Support Components 3.6 Manholes, Handholes, and Fittings 3.7 Boller Assembly 3.8 Heating Surface and Capacity 3.9 Boller Capacity Calculation Questions and Problems Chapter Combustion 129 133 138 140 145 147 148 151 155 181 of Fuels 165 4.1 The Combustion Process 4.2 The Theory of Combustion 4.3 The Air Supply 4.4 Coal 4.5 Fuel 011 4.6 Gas 4.7 By-Product Fuels 4.8 Control of the Combustion Process Questions and Problems Chapter Boiler Settings, Auxiliary Equipment 5.1 Boller Settings Combustion 68 77 89 89 90 90 91 92 93 93 95 96 108 108 109 118 111 111 117 125 185 189 182 188 200 208 208 211 218 Systems, and 221 221 Hand Firing Stokers 5.3.1 Underfeed Stokers 5.3.2 Overfeed Stokers 5.4 Pulverized Coal 5.4.1 Contact Mills 5.4.2 Ball Mills 5.4.3 Impact Mills 5.4.4 Mill Feeders 5.4.5 Gravimetric Feeders 5.4.6 Burners 5.4.7 Lighters 5.4.8 Flame Safety System 5.4.9 Operation 5.5 Fuel 011 5.5.1 Rotary Burners 5.5.2 Steam- or Air-Atomizing Burners 5.5.3 Pressure- Type Burners 5.6 Gas 5.7 011-and Gas-Firing Safety Precautions 5.8 Automatic Operation of Boilers 5.9 Stacks 5.10 Mechanical Draft: Fans 5.11 Steam and Air Jets 5.12 Flues and Ducts Questions and Problems 5.2 5.3 Chapter 7.1 7.2 Operation and Maintenance Boller Startup Normal Operation 7.2.1 Combustion Control 7.2.2 Ash Handling 7.2.3 Water Supply 7.2.4 Boller Efficiency 224 227 229 238 261 265 270 272 273 274 276 282 282 282 289 293 294 296 302 308 309 313 317 325 326 327 331 Boiler Accessories 6.1 Water Columns 6.2 Fusible Plugs 6.3 Pressure Measurement 6.4 Temperature Measurement 6.5 Feedwater Regulators 6.6 Safety Valves 6.7 Blowdown Equipment 6.8 Nonreturn Valves 6.9 Steam Piping 6.10 Sootblowers 6.11 Valves 6.12 Instruments and Automatic Control Systems Questions and Problems Chapter ix of Boilers 331 338 340 343 343 350 364 369 373 374 380 386 399 403 403 407 40B 409 41IJ 421 x Contents Contents 7.2.5 Insulation and Lagging 7.3 Operating Characteristics of Fluidized Bed Boilers 7.3.1 Circulating Fluid Bed (CFB) Boilers 7.3.2 Bubbling Fluid Bed (BFB) Boilers 7.4 Abnormal Operation 7.5 Idle Boilers 7.6 Maintenance 7.7 Boiler Internal Inspection 7.8 Evaluating the Condition of a Boiler 7.9 Making Repairs Questions and Problems 425 425 426 427 428 432 434 442 445 446 451 9.5.2 Design Considerations 9.5.3 Materials of Construction 9.6 Condenser Auxiliaries Questions and Problems Chapter 10 Operating and Maintaining Steam Turbines, Condensers, Cooling Towers, and Auxiliaries 10.1 10.2 Chapter Pumps 8.1 Pumps 8.2 Injectors 8.3 Duplex Pumps 8.4 Power Pumps 8.5 Vacuum Pumps 8.6 Rotary Pumps 8.7 Centrifugal Pumps 8.8 Facts about Fluids and Pumping 8.9 Factors Affecting Pump Operation 8.10 Considerations for Pump Selection 8.11 Pump Installation and Operation 8.12 Pump Testing and Calculations 8.13 Pump Maintenance Questions and Problems Chapter Steam Turbines, Condensers, and Cooling Towers 9.1 9.2 9.3 9.4 9.5 Steam Turbines 9.1.1 Turbine Types and Applications 9.1.2 Turbine Stage Design 9.1.3 Major Components of a Turbine Turbine Design and Construction 9.2.1 Thrust Bearing 9.2.2 Packing 9.2.3 Governors 9.2.4 Lubrication 9.2.5 Turbine Control 9.2.6 Erection of the Steam Turbine 9.2.7 Relief Valves and Rupture Disks for Turbines 9.2.8 Turbine Piping Electric Generators Condensers 9.4.1 Surface Condensers 9.4.2 Air-Cooled Condensers 9.4.3 Condenser Materials and Construction Cooilng Towers 9.5.1 Types of Cooling Towers 455 456 457 460 470 473 475 479 492 493 495 496 500 506 512 517 517 523 529 531 536 547 549 551 557 558 561 563 565 565 568 569 572 573 576 578 Turbines 10.1.1 Turbine Operation 10.1.2 Turbine Maintenance Condensers 10.2.1 Surface Condenser Operation 10.2.2 Surface Condenser Maintenance 10.2.3 Air-Cooled Steam Condenser Operation Cooling Towers 10.3.1 Operation of Cooling Towers 10.3.2 Maintenance of Cooling Towers 10.4 Auxiliaries 10.4.1 Traveling Screens 10.4.2 Pumps 10.4.3 Steam-Jet Ejectors and Vacuum Pumps 10.4.4 Vacuum Gauges Questions and Problems 10.3 Chapter 11 Auxiliary Steam-Plant Equipment Feedwater Heaters 11.1.1 Closed Feedwater Heaters 11.1.2 Open Feedwater Heaters 11.1.3 Operation and Maintenance of Feedwater Heaters 11.2 Condensate Polishing Systems 11.3 Raw Water Treatment 11.3.1 lon-Exchange Water Conditioners 11.3.2 Evaporators Boiler Blowdown 11.4 11.5 Piping System 11.6 Steam Traps 11.7 Pipeline Separators and Strainers 11.8 Lubricants and Lubricating Devices Questions and Problems 11.1 Chapter 12 Environmental Control Systems 12.1 12.2 12.3 12.4 Introduction Environmental Considerations Sources of Plant Emissions Available Technologies for the Control of Emissions 12.4.1 S02 Control 12.4.2 NOx Control 12.4.3 Particulate Control xl 585 587 587 592 595 595 601 605 611 611 613 615 616 618 621 622 622 624 624 625 626 629 630 630 632 644 645 647 648 652 654 656 665 671 674 682 685 685 685 686 688 688 689 689 All ,",UIJU:trII::t Preface 12.5 12.6 Regulatory Requirements Particulate and Sulfur Dioxide Removal Requirements 12.6.1 Particulate Removal 12.6.2 Sulfur Dioxide Removal 12.6.3 Industrial Boilers 12.7 Equipment for Particulate Emission Control 12.7.1 Mechanical Collectors 12.7.2 Electrostatic Precipitators 12.7.3 Bag Fllterhouses 12.8 Equipment for Sulfur Dioxide Scrubber Systems 12.8.1 Wet Scrubbers 12.8.2 Dry Scrubbers 12.9 Systems for Control of Nitrogen Oxides (NO ) x Questions and Problems Chapter 13 Waste-to-Energy Plants 13.1 13.2 13.3 13.4 13.5 13.6 13.7 13.8 13.9 13.10 Introduction Waste Dlsposal-A Worldwide Problem Potential Energy from MSW Landfills Solid Waste Composition Types of Energy-Recovery Technologies Mass Burning Refuse-Derived Fuel (RDF) Burning Operation and Maintenance of Refuse Boilers Recycling 13.10.1 Advantages and Disadvantages of Recycling 13.10.2 Economics and Quality Products from Recycling 13.11 Material Recovery Facilities (MRFs) 13.12 Waste-to-Energy Plants and Recycling Questions and Problems 690 691 691 693 694 695 695 697 704 710 711 715 723 725 729 729 732 735 736 737 741 742 750 757 761 761 764 764 769 773 Appendix A Unit Conversions 775 Appendix B Geometric 781 Appendix C Steam Tables and Charts 783 Appendix D Answers 797 Glossary Index Formulas to Problems 801 811 I am very pleased to have the opportunity to complete the seventh edition of this book, a book whose six previous editions have assisted thousands of people for over 60 years in the understanding of steam power plants The presentation of material in the form of illustrations and clear descriptions has helped many to gain the fundamental knowledge of the many complex systems found in these plants This knowledge has allowed them to further their careers in this field and, where required for an operating license, has assisted many in the passing of an operator's examination Presented in a practical and easily understood format, as in previous editions, the complex systems found in power plants are described, and the means by which they are operated and maintained are defined so that the operation is safe, reliable, economic, and, very important, performed in an environmentally acceptable manner Thus, the combustion processes of solid, liquid, and gaseous fuels are described, as well as the boilers that are designed to handle this combustion and to produce the steam necessary for the particular power plant, whether it be for a process, for heating, or for the production of electricity Ai; society accepts the technological advances of this computer age, it is often forgotten that it is the reliable operation of power plants, particularly steam power plants, that provide the energy source for these advancements Throughout the world, 80 to 90 percent of the electricity produced results from steam The fuel energy for this is predominantly from the combustion of fossil fuels, with coal still providing a very significant margin over oil, natural gas, and other fuels requiring combustion Steam Plant Operation continues to present the sytems necessary to produce this power-boilers, combustion equipment, steam turbines, pumps, condensers, etc.-that are required for efficient operation, as well as the environmental control equipment to control plant emissions within regulated bounds xIII Chapter Since power plant equipment remains in operation for many decades, some older equipment descriptions are retained in this edition; they continue to remain in operation, and they illustrate operating fundamentals In this edition, this information is complemented with the principles of operation on modern fluidized bed boilers, which can handle hard-to-burn solid fuels and control emissions of nitrogen oxides (NO) and sulfur dioxides (S02)' In addition, cogeneration facilities are introduced, and these facilities join gas turbine technology with a steam power plant to form a combined facility Where necessary, updated material is introduced to reflect recent trends in power plant system design There still remain critical decisions on the handling of municipal solid waste, as its disposal remains a problem in the United States and worldwide Waste-to-energy plants remain a viable solution to this problem; however politics have delayed many facilities Recycling has become an important part of this solution, and the advantages and disadvantages of recycling are presented as well as their integration with waste-to-energy plants The use of material recycling facilities and the various systems that are used for their operation are described This edition no longer includes the descriptions of the venerable steam engine of which few remain in operation today The information included in previous editions assisted those who took examinations where questions on the subject were still asked The elimination of this material allows the addition of current technology on other subjects It is a privilege to be able to continue the tradition of this book by presenting material in an easily understood format This idea was originally established in earlier editions by my father, Herbert Lammers, and his friend and co-author, Everett Woodruff These two practical men devoted much of their lives to the safe and efficient operation of steam power plants As a result, Steam Plant Operation has assisted many in the basic understanding of steam-plant technology Finally, without the contribution of illustrations and information by many suppliers and designers of power plant equipment, this book would not have been possible I am sincerely grateful to all who assisted me in this project-the seventh edition of Steam Plant Operation Thomas F Lammers Steam and Its Importance In today's modern world, all societies are involved to various degrees with technological breakthroughs that are attempting to make our lives more productive and more comfortable These technologies include sophisticated electronic devices, the most prominent of which are computer systems Many of the systems in our modern world depend on a reliable and relatively inexpensive energy source electricity With the availability of electricity providing most of the industrialized world a very high degree of comfort, the source of this electricity and the means for its production are often forgotten It is the power plant that provides this critical energy source, and in the United States approximately 90 percent of the electricity is produced from power plants that use steam as an energy source, with the remaining 10 percent of the electricity produced primarily by hydroelectric power plants In other parts of the world, similar proportions are common for their electric production The power plant is a facility that transforms various types of energy into electricity or heat for some useful purpose The energy input to the power plant can vary significantly, and the plant design to accommodate this energy is drastically different for each energy source The forms of this input energy can be as follows: The potential energy of an elevated body of water, which, when used, becomes a hydroelectric power plant The chemical energy that is released from the hydrocarbons contained in fossil fuels such as coal, oil, or natural gas, which becomes a fossil fuel fired power plant The solar energy from the sun, which becomes a solar power plant Steamand Its Importance The fission or fusion energy that separates or attracts atomic particles, which becomes a nuclear power plant With any of these input sources, the power plant's output can take various forms: Heat for a process or for heating Electricity that is subsequently converted into other forms of energy Energy for transportation such as for ships electricity, heat, or a steam process required to develop a needed product such as paper, the goal is to have that product produced at the lowest cost possible, and this often is related to the heat required to produce the steam or the actual end product In every situation, however, the steam power plant must first obtain heat This heat must come from an energy source, and this varies significantly, often based on the plant's location in the world These sources of heat could be A fossil fuel-coal, In these power plants, the c()nversion of water to steam is the predominate technology, and this book will describe this process and the various systems and equipment that are used commonly in today's operating steam power plants Each power plant has many interacting systems, and in a steam power plant these include fuel and ash handling, handling of combustion air and the products of combustion, feedwater and condensate, steam, environmental control systems, and the control systems that are necessary for a safe, reliable, and efficiently run power plant The seventh edition of Steam-Plant Operation continues to blend descriptions and illustrations of both new and older equipment, since both are in operation in today's power plants One noticeable change in this edition is the elimination of the discussion on steam engines These wonderful mechanical devices, which were so critical to industry throughout the world for many decades as they powered machinery, have been nearly totally replaced, most often by electric motors 1.1 The Use of Steam Steam is a critical resource in today's industrial world It is essential for the production of paper and other wood products, for the preparation and serving of foods, for the cooling and heating of large buildings, for driving equipment such as pumps and compressors, and for powering ships However, its most important priority remains as the primary source of power for the production of electricity Steam is extremely valuable because it can be produced anywhere in the world by using the heat that comes from the fuels that are available in the area Steam also has unique properties that are extremely important in producing energy Steam is basically recycled, from steam to water and then back to steam again, all in a manner that is nontoxic in nature The steam plants of today are a combination of complex engineered systems that work to produce steam in the most efficient manner that is economically feasible Whether the end product of this steam is oil, or natural gas A nuclear fuel such as uranium Other forms of energy, which can include waste heat from exhaust gases of gas turbines; bark, wood, bagasse, vine clippings, and other similar waste fuels; by-product fuels such as carbon monoxide (CO), blast furnace gas (BFG), or methane (CH4); municipal solid waste (MSW); sewage sludge; geothermal energy; and solar energy Each of these fuels contains potential energy in the form of a heating value, and this is measured in the amount of British thermal units (Btus) per each pound or cubic feet of the fuel (i.e., Btullb or Btu/ft3) depending on whether the fuel is a solid or a gas (Note: A British thermal unit is about equal to the quantity of heat required to raise one pound of water one degree Fahrenheit.) This energy must be released, and with fossil fuels, this is done through a carefully controlled combustion process In a nuclear power plant that uses uranium, the heat energy is released by a process called fission In both cases the heat is released and then transferred to water This can be done in various ways, such as through tubes that have the water flowing on the inside As the water is heated, it eventually changes its form by turning into steam As heat is continually added, the steam reaches the desired temperature and pressure for the particular application The system in which the steam is generated is called a boiler Boilers can vary significantly in size A relatively small one supplies heat to a building, and other industrial-sized boilers provide steam for a process Very large systems produce enough steam at the proper pressure and temperature to result in the generation of 1300 megawatts (MW) of electricity in an electric utility power plant Such a large power plant would provide the electric needs for over million people Small boilers that produce steam for heating or for a process are critical in their importance in producing a reliable steam flow, even though it may be saturated steam at a pressure of 200 psig and a steam flow of 5000 lblh This then can be compared with the large Chapter One utility boiler that produces 10 million pounds of superheated steam per hour at pressures and temperatures exceeding 3800 psig and 1000°F To the operator of either size plant, reliable, safe, and efficient operation is of the utmost importance The capacity, pressure, and temperature ranges of boilers and their uniqueness of design reflect their applications and the fuel that provides their source of energy Not only must the modern boiler produce steam in an efficient manner to produce power (heat, process, or electricity) with the lowest operational cost that is practical, but also it must perform in an environmentally acceptable way Environmental protection is a major consideration in all modern steam generating systems, where low-cost steam and electricity must be produced with a minimum impact on the environment Air pollution control that limits the emissions of sulfur dioxide (S02) and other acid gases, particulates, and nitrogen oxides (NO) is a very important issue for all combustion processes For example, low NOx burners, combustion technology, and supplemental systems have been developed for systems fired by coal, oil, or natural gas These systems have met all the requirements that have been imposed by the U.S Clean Air Act, and as a result, NO levels have been reduced by 50 to 70 percent from uncontrolled levels.x 1.2 The Steam-Plant Cycle The simplest steam cycle of practical value is called the Rankine cycle, which originated around the performance of the steam engine The steam cycle is important because it connects processes that allow heat to be converted to work on a continuous basis This simple cycle was based on dry saturated steam being supplied by a boiler to a power unit such as a turbine that drives an electric generator The steam from the turbine exhausts to a condenser, from which the condensed steam is pumped back into the boiler It is also called a condensing cycle, and a simple schematic of the system is shown in Fig 1.1 This schematic also shows heat (Qin) being supplied to the boiler and a generator connected to the turbine for the production of electricity Heat (Qout) is removed by the condenser, and the pump supplies energy (W ) to the feedwater in the form of a pressure increase to allow it to flo~ through the boiler A higher plant efficiency is obtained if the steam is initially superheated, and this means that less steam and less fuel are required for a specific output If the steam is reheated and passed through a second turbine, cycle efficiency also improves, and moisture in the steam is reduced as it passes through the turbine This moisture reduction minimizes erosion on the turbine blades By the addition of regenerative feedwater heating, the original Rankine cycle was improved significantly This is done by extracting steam from various stages of the turbine to heat the feedwater as it is pumped from the condenser back to the boiler to complete the cycle It is this cycle concept that is used in modern power plants, and the equipment and systems for it will be described in this book 1.3 The Power Plant The steam generator or boiler is a major part of the many systems that comprise a steam power plant A typical pulverized-coal-fired utility power plant is shown schematically in Fig 1.2 The major systems of this power plant can be identified as Coal receipt and preparation Coal combustion and steam generation Environmental protection Turbine generator and electric production Condenser and feedwater system Heat rejection, including the cooling tower In this example, the fuel handling system stores the coal supply, prepares the fuel for combustion by means of pulverization, and then transports the pulverized coal to the boiler A forced-draft (FD) fan supplies the combustion air to the burners, and this air is preheated in an air heater, which improves the cycle efficiency The heated air is also used to dry the pulverized coal A primary air fan is used to supply heated air to the pulverizer for coal drying purposes and is the Steam and Its Importance source of the primary air to the burners as the fuel-air mixture flows from the pulverizers to the burners The fuel-air mixture is then burned in the furnace portion of the boiler ' The boiler recovers the heat from combustion and generates steam at the required pressure and temperature The combustion gases are generally called flue gas, and these leave the boiler, economizer, and finally the air heater and then pass through environmental control equipment In the example shown, the flue gas passes through a particulate collector, either an electrostatic precipitator or a bag filterhouse, to a sulfur dioxide (S02) scrubbing system, where these acid gases are removed, and then the cleaned flue gas flows to the stack through an induced-draft (ID) fan Ash from the coal is removed from the boiler and particulate collector, and residue is removed from the scrubber Steam is generated in the boiler under carefully controlled conditions The steam flows to the turbine, which drives a generator for the production of electricity and for distribution to the electric system at the proper voltage Since the power plant has its own electrical needs, such as motors, controls, and lights, part of the electricity generated is used for these plant requirements After passing through the turbine, the steam flows to the condenser, where it is converted back to water for reuse as boiler feedwater Cooling water pas~es through the condenser, where it absorbs the rejected heat from condensing and then releases this heat to the atmosphere by means of a cooling tower The condensed water then returns to the boiler through a series of pumps and heat exchangers, called feedwater heaters, and this process increases the pressure and temperature of the water prior to its reentry into the boiler, thus completing its cycle from water to steam and then back to water The type of fuel that is burned determines to a great extent the overall plant design Whether it be the fossil fuels of coal, oil, or natural gas, biomass, or by-product fuels, considerably different provisions must be incorporated into the plant design for systems such as fuel handling and preparation, combustion of the fuel, recovery of heat, fouling of heat-transfer surfaces, corrosion of materials, and air pollution control Refer to Fig 1.3, where a comparison is shown of a natural gas-fired boiler and a pulverized-coal-fired boiler, each designed for the same steam capacity, pressure, and temperature This comparison only shows relative boiler size and does not indicate the air pollution control equipment that is required with the coalfired boiler, such as an electrostatic precipitator and an S02 scrubber system Such systems are unnecessary for a boiler designed to burn natural gas In a natural gas-fired boiler, there is minimum need for fuel storage and handling because the gas usually comes directly from the Appendix Answers to Problems Chapter 3.3 3.1416 in2; 2546 psi 3.6 2827.4 in2 (19.6 ft2) 3.7 2,120,550Ib 3.8 1% in, or 1.625 in 3.18 27,150 psi elastic limit 56,561 psi ultimate strength 3.19 610,7251b 3.20 7,776,000 lb 3.21 1354 psi 3.22 t 3.26 1381 ft2 3.27 115 boiler hp 3.29 269.4 X 106 Btu/h 3.33 h at 900 psia saturated = 1195.4 Btullb hat 900 psia and 950°F = 1480 Btullb Degrees superheat = 418.02°F = 3.21 in; commercial size t = 3.25 in 798 AppendixD Answersto Problems 3.34 17,518,13,841, and 3200 Btu/h per square foot (Btu!hlft2); 88,543 Btu/h per cubic foot (Btu!hlft3) Chapter 33 ft 8.44 112.5 psi 8.45 3.53 in in diameter 8.46 102 strokes per minute 8.47 15.15 hp 8.48 485.4 hp 8.49 motor size, 550 hp input, 393.4 kW , 4.10 2.091b of 0!1b of coal; 9.02 lb of airllb of coal 4.15 28.71 percent 4.17 13.53 lb of airllb of coal 4.18 12,336 Btu/lb 4.30 22 3° API Chapter 5.65 8.43 Chapter 10 1.135 in of water theoretical (0.908 in of water available) Chapter 10.10 in Hg = 0.491 psi 3.5 in Hg = 1.72 psi 10.28 1.83 psi 6.4 255.8 psi 10.29 0.5 psi 6.5 6.5 psi low 10.30 0.74 psi 6.20 3976 lb Chapter 11 Chapter 11.21 $253,560/yr 8.34 43.3 psi 11.22 7.74 in; use in 8.35 288.7 ft 11.24 6.78 in 8.36 840 ft3; 1,451,520 in3; 52,500 lb; 6302.5 gal 8.37 I 5891 gal 8.38 48.4 gpm; 2906 gph 8.39 130 8.40 9.12 h 8.41 256.6 psi; 593 ft ~ 8.42 3757 gal ~ , 799 Glossary Absolute Pressure The common gauge expresses a pressure in pounds per square inch called gauge pressure When the gauge is open to the atmosphere, it reads zero The gauge pressure plus atmospheric pressure is known as absolute pressure Atmospheric pressure is 14.7 psi at sea level; it varies with location and atmospheric conditions It is accurately indicated by a barometer Absolute Temperature The temperature 460 is the absolute temperature as read on the Fahrenheit scale plus Absolute Zero of Pressure The starting point of the absolute-pressure scale is absolute zero It is lower than a zero gauge by an amount equal to the atmospheric pressure Absolute Zero of Temperature The temperature 460 below zero Fahrenheit is absolute zero At absolute zero there is a complete absence of heat Absolute zero has never been attained, but it has been approached within a few degrees , Acidity Water is a chemical combination of hydrogen (H) and oxygen (0) that is represented by the formula H20 It may also be treated as a chemical combination of hydrogen ions (H+) and hydroxyl ions (OH-) If there is a greater number of hydrogen ions than hydroxyl ions as a result of the chemical action of impurities or solutes, the solution is acidic A greater number of hydroxyl ions results in an alkaline solution The degree of acidity or alkalinity of a substance is known as the hydrogen-ion concentration and is called the pH value A pH value of 7.0 indicates neutral water; a value less than 7.0, acidity; and a value greater than 7.0, alkalinity - Air Heater A heat exchanger that transfers heat from a high-temperature medium, such as flue gas or steam, to incoming air Alkalinity See Acidity 802 Glossary Glossary transfer is by conduction Heat is conducted through the metal in the shell and tubes of a boiler Substances differ widely in their ability to conduct heat Metal is a good conductor; soot and boiler scale are very poor conductors Heat transfer by conduction is a primary method used in fluidized bed boiler designs Attemperator This is also called a desuperheater, and it reduces the temperature of superheated steam at higher loads to permit a constant steam temperature over a defined load range A deep bulge in the shell of a fire-tube boiler , Bag 803 Blowdown The continuous removal of concentrated boiler water for the purpose of controlling the total solids concentration in the remaining Continuous Bag Filterhouse A device consisting of multiple filter bags designed to remove dust particles from the flue-gas stream It is also commonly called a bag house or a fabric filter water Banking Convection When heat is carried by means of the movement of currents within a body, it is said to be transmitted by convection The change in density of the substance, due to the heating, causes the movement The circulation of water in a boiler carries heat from the tubes to the boiler drum Boiler A closed vessel in which water is heated and steam is generated and superheated, if desired, all performed under pressure by the application of heat Conversion of Heat Energy and Mechanical Energy Heat energy and mechanical energy are convertible There is a direct relation between heat energy and mechanical energy; 778 ft lb is equivalent to Btu Boiling Out The process of boiling highly alkaline water in boiler pressure parts for the purpose of removing oils, greases, etc., prior to normal operation or after initial construction or after major repairs Critical Pressure The burning of solid fuel on a grate at a rate that is sufficient to maintain ignition only It is also a combustion rate that is just sufficient to maintain normal operating pressure but with no steam capacity Boiling Point of Water The pressure at which there is no difference between the liquid and vapor states for water This occurs at a pressure of 3206 psia The removal of air and gases from boiler feedwater prior to its introduction to a boiler A deaerator serves this purpose and is part of the feedwater heating system Deaeration Water at atmospheric pressure boils at 212°F or 1000C Boyle's Law of Gases When the temperature of a gas remains constant, the volume will be reduced to one-half if the absolute pressure is doubled; the absolute pressure will be reduced to one-half if the volume is doubled (The volume of a gas varies inversely as the pressure: Pi Vi = P2 V2.) Degrees of Superheat The number of degrees between the superheated steam temperature and the saturated steam temperature at a particular pressure Demineralizer British Thermal Unit (Btu) A British thermal unit is used to measure heat energy It is defined as the quantity of heat required to raise the temperature of lIb of water 1°F Caustic Embrittlement This refers to the cracking of boiler steel occurring while the boiler is in service but not subjected to excessive pressure or temperature Such failures are attributed to the boiler water's being too caustic, that is, too alkaline; hence the term caustic embrittlement Collection Efficiency of Particulates The ratio of the weight of dust collected to the total weight of dust entering the collector J The chemical combination of oxygen with the combustible elements of a fuel, such as carbon and hydrogen, and this results in the production of heat Combustion Condensation When steam or any other vapor is subjected to a change of state which reduces it to a liquid, it is said to be condensed Steam is condensed in a condenser or heater by extracting heat The water formed is called condensate Conduction ~en heat is transmitted through a substance or from one substance in contact with another but without the bodies' themselves moving, the An ion-exchange system that removes solids from water Density The density of a substance is the number of units of weight that it contains per unit of volume Water has a density of62.5Ib/ft • The pressure used in the design of a boiler for the purpose of determining the minimum permissible thickness of pressure parts and also other characteristics of the boiler Design Pressure , Dew Point The temperature at which a vapor liquefies is called the dew point Downcomer A tube or pipe in a boiler circulating water system through which water flows downward On a boiler with a steam drum only, the downcomer is connected from the drum to the lower furnace waterwall headers On a twodrum boiler, the downcomer is connected to the lower drum Draft The difference between atmospheric pressure and a lower pressure that is present in a boiler The drop in the pressure of flue gas between two points within a system that is caused by a resistance to flow Draft Loss 804 Glossary Glossary Economizer Heat-transfer surface that transfers heat from the flue gas to the boiler feedwater Efficiency The efficiency of any system or piece of equipment is the output divided by the input, sometimes stated as the useful energy divided by the energy expended The input and output may be expressed in any energy units They must, however, be in the same units Electrostatic Precipitator A device for collecting dust from a flue gas stream by placing an electric charge on the dust particle and removing that particle onto a collecting plate ' Energy Energy is the ability to work Mechanical energy is expressed in footpounds or horsepowerhours; electric energy, in kilowatthours; and heat energy, in British thermal units Enthalpy Enthalpy is the number of Btus that a substance contains above a specific datum In the case of water and steam the reference condition is water at 32°F The enthalpy values given in the steam tables are the Btus required to raise water or steam from 32°F to the specific temperature and pressure These values are also referred to as total heat It is expressed as Btus per pound of fluid (Btw1b) Evaporation The process of changing a liquid into a vapor or a gas is known as vaporization This is usually accomplished by the application of heat Excess Air The combustion of fuel is primarily the combining of combustible substances of the fuel with oxygen of the air A fuel requires a definite amount of oxygen, therefore air, to result in complete combustion The amount of air used in excess of this amount is known as excess air Excess air is necessary to result in complete combustion, but too much causes a decrease in efficiency Expansion A change in temperature produces a change in the size of practically all substances Each material changes a different amount for a given change in temperature The change in length per degree of temperature change is known as the linear coefficient of expansion Such coefficients for common materials may be found in handbooks If the pressure of a gas is kept constant, the volume will change in proportion to the absolute temperature Factor of Evaporation If 970.3 Btu is added to lb of water that is at atmosphehc pressure and 212°F, it will be converted into steam and the steam will be at atmospheric pressure and 212°F This is termed evaporation from and at 212°F, or, briefly, from and at The heat added to a pound of water by the boiler (from the time at which it enters until it leaves as steam) divided by 970.3 is the factor of evaporation Feedwater This is the water that enters a boiler during operation, and it includes mak~ wate! Q.ndcondensate from the condenser ' 805 Flame Impingement The contact on a surface by a flame from a burner that results in carbon deposits, incomplete combustion, and the high potential for failure of furnace wall tubes Fluidized Bed Combustion A process where a fuel is burned in a bed of granulated particles (such as sand or limestone) which are maintained in a mobile suspension by the upward flow of air and combustion products Fly Ash Suspended ash particles carried in the flue gas Force Force is that which produces, or tends to produce, motion The force on the blade of a steam turbine produces motion The force exerted on the head of a steam boiler does not produce motion, but it tends to; both are examples of force Freezing Point of Water Water freezes at 32 on the Fahrenheit scale of temperature measurement This corresponds to on the centigrade scale When water freezes, its volume increases by about percent Furnace Heat Release This is the number of Btus developed per hour in each cubic foot of furnace volume It is usually assumed that all the heat available in the fuel burned is transformed into heat in the combustion process Therefore, the furnace heat release equals the total fuel burned per hour times the Btu content divided by the furnace volume Fusion Temperature Fusion is the act or process of melting by heat or the state of being fused or melted For coal, the fusion temperature is reported as initial-deformation temperature (LD.T.), ash-softening temperature (A.S.T.), and ash-fusion temperature (A.F.T.), the test being made under a reducing atmosphere Grindability The characteristic of coal that identifies its ability to be pulverized and is used as a factor in determining the capacity of a pulverizer Head Head is the energy per pound of fluid Potential head: This refers to energy of position, measured by work possible in dropping a vertical distance Static pressure: This refers to energy per pound due to pressure; it is the height to which liquid can be raised by a given pressure Velocity: This refers to kinetic energy per pound; it is the vertical distance a liquid would have to fall to acquire the velocity V Total: This refers to the net difference between total suction and discharge heads Net Positive Suction (NPSH): This is the amount of energy in the liquid at the pump datum It is the measure of the energy increase imparted to the liquid by the pump 806 Heat Glossary Heat is a form of energy Heat Content of Steam or Total Heat This refers to the Btus that must be added to produce steam at the condition in question Water at 32°F is usually taken as the starting point , Horsepower Horsepower (hp) is a unit of power, which is defined as the rate at which work is being performed One horsepower is equal to 33,000 ft Ib/min Horsepowerhour A horsepowerhour is hp of energy expended continuously for h (1 hp h = 2545 Btu.) Glossary 807 and also varies from season to season Its content· also changes based on the recycling programs in the area Over-Fire Air Combustion air that is admitted into the furnace at a point above the fuel bed Package Boiler A boiler that is shipped complete with fuel-burning equipment (normally oil and gas fired), mechanical-draft equipment, automatic controls, and accessories Shipment takes place in one or more major sections Hydrostatic Test A strength and tightness test of a closed pressure vessel by water pressure Power Power is the rate at which work is done Footpounds express work, but the rate or time required determines the power: 33,000 ft lb/min is one horsepower Incomplete Combustion The partial chemical combination of the combustible elements of a fuel with the oxygen in the air that results in unburned carbon loss Pressure Drop The difference in pressure between two points in a system For example, a superheater pressure drop is the difference in pressure from the boiler drum outlet, through the superheater tubes, to the superheater outlet Industrial Boiler A boiler that produces steam or hot water primarily for process applications for industrial use with some use for heating Industrial boilers cover a wide range of capacities, pressures, and temperatures and can burn a variety of solid, liquid, and gaseous fuels Some units are designed for small electric utility applications Kilowatt A kilowatt is a unit of electric power and is equal to 1000 watts For direct current, watts equal amperes times volts (P = I X E); for alternating current (single phase), watts equal amperes times volts times power factor (P = I X E X PF, where I = amperes, E = volts, P = watts, and PF = power factor) Kilowatthour Kinetic Energy A kilowatthour is kW of energy expended continuously for h Kinetic energy is energy that a body has due to its motion Latent Heat of Evaporation When a liquid is vaporized, a large amount of heat must be added to produce the change This heat does not increase the temperature and is therefore called latent heat The latent heat of vaporization of water at atmospheric pressure is 970.3 Btu Law 01 Conservation of Energy The amount of energy in existence is constant The machines that are built and operated not produce energy; they merely change it from one form to another Primary Air Combustion air that is introduced with the fuel at the burners Products of Combustion The gases, vapors, and solids that result from the combustion of fuel It is often called flue gas Proximate Analysis The analysis of a solid fuel that determines the content of moisture, volatile matter, fixed carbon, and ash as percentages of the total weight of the fuel Radiation, Thermal Radiation is the transmission of heat without the use of a material carrier The earth receives heat from the sun, and for most of that distance, the heat travels through a vacuum When a furnace door is open, you can feel the heat even though air is being pulled into the furnace through the door The lower rows of furnace and boiler tubes receive much heat by radiation Radiated heat is very similar to visible light; they both travel at the same speed, namely, 186,000 miles per second Reheater A portion of a boiler that adds heat to steam to raise its temperature after the steam has performed part of its work This is usually done on a utility boiler application after the initial superheated steam passes through the highpressure section of a turbine The lower-pressure steam from this section of the turbine returns to the boiler through the reheater, where the steam temperature is increased, and then returns to the low-pressure section of the turbine Mechanical Equivalent of Heat This is sometimes called Joule's equivalent: 778 ft· Ib of mechanical energy is equivalent to Btu of heat energy Safety Valve A valve that is spring loaded and automatically opens when pressure increases to the valve setting It is used to prevent pressure in a vessel from exceeding the design pressure Municipal Solicl.Waste (MSW) Solid waste material as collected from households and commercial ~ources It is highly heterogeneous in nature in that it varies in appearance and content in various parts of a country and the world Saturated Steam Saturated steam is steam that contains no moisture It is saturated with heat, since additional heat will raise the temperature above the boiling point and the removal of heat will result in the formation of water 808 Glossary Glossary Secondary Air Combustion air that is supplied to a furnace and supplements the primary air Smoke Smoke refers to flue gases that contain enough unburned carbon and hydrocarbons to cause discoloration The degree of coloration depends on the carbon present Specific Heat Different substances have different heat capacities In fact the heat capacity of some substances changes as the temperature changes By the definition of a Btu, the heat content of a paund of water per degree Fahrenheit is The specific heat of any substance is the heat required to raise lIb of it 1°F 809 Thermodynamics The science that describes and defines the transformation of one form of energy into another: chemical to thermal, thermal to mechanical, mechanical to electrical Torque Torque is a force that tends to produce rotation It is measured by the product of the force and the applied distance from the center of rotation A force oflOO Ib applied at a distance of2 ft will produce 200 ft ·lb of torque Ultimate Analysis The chemical analysis of a fuel that determines the contents of carbon, hydrogen, sulfur, nitrogen, chlorine, oxygen, and ash as percentages of the total weight of the fuel Steam Generator A boiler to which water, fuel, and air or waste heat are supplied and in which steam is generated It includes a furnace, heat-transfer heating surface, and fuel-burning equipment, and it also may include a superheater, reheater, economizer, air heater, flues and ducts, controls, and various auxiliaries Utility Boiler A boiler designed to produce steam for the production of electricity in the utility industry Stoker Consists of a system that includes a fuel-feeding mechanism and a grate It feeds a solid fuel into a furnace and distributes it over a grate where air is admitted to the fuel for its combustion A means is provided for the removal of the ash that resulted from combustion Viscosity Viscosity is the resistance that a fluid offers to flow The viscosity of lubricating oil is an important characteristic Viscosity varies with the temperature Stoker Combustion Rate This rate is expressed in terms of the number of pounds of fuel or the Btu developed per square foot of stoker grate area per hour Sulfur Dioxide Scrubber A device for the removal of sulfur dioxide from flue gases The process is often called flue-gas desulfurization Superheated Steam Steam that has been raised to a temperature higher than the boiling temperature corresponding to the boiling pressure is said to be superheated Superheater Heat-transfer surface that transfers heat from the flue gas to the steam for the purpose of raising the temperature of the steam above its saturation temperature TemJ¥trature The temperature of a substance must be carefully distinguished from the heat content Temperature is thermal pressure and is a measure of the ability of a substance to give or receive heat from another substance Tertiary Air Combustion air that is supplied to a furnace and supplements both the primary and secondary air This is often part of staged combustion to control NOx emissions that result from the combustion process Thermal EfflcRlncy the cycle T}le net work produced divided by the total heat input to ' Vacuum The word vacuum refers to pressures below atmospheric, expressed in inches of mercury (14.7 psi atmospheric equals 30 in Hg) units Wet Steam When steam contains particles of water that have not been evaporated, it is said to be wet Work Work is force exerted through a distance No mention is made of the time required Work is conveniently expressed in footpounds Index Absolute pressure, 155, 170, 801 Absolute temperature, 170, 801 Absolute zero, 155, 170, 801 Acid rain, 192 Air, 176 primary, 81,105,167,224,227,244, 263-265,280,286,427,807 secondary, 81, 105, 167, 168, 222, 226, 263, 280,427,808 specific heat of, 780 tertiary, 81, 427, 809 theoretical air required (see Combustion) Air heater, 5, 16,60-66, 154,522,801 corrosion of, 64, 66, 176 regenerative, 12, 63, 89 tubular, 12, 63 Air pollution control (see Environmental control systems) Analysis of flue gas, 179-181,211-217 Ash handling, 7, 226, 228, 232, 248, 250, 252, 258,282,409,686,696,703,746 Ash (coal), 72, 76, 211, 262, 409, 686 Atmospheric pressure, 27, 170, 315, 456, 492, 501,570,600,625 Atom, 172 Atomic weight, 172, 173 Attemperator (desuperheater), 46, 55, 58, 85, 410,802 Auxiliary steam plant equipment, 629-681 Backpressure (see Turbines) Bag filterhouses (baghouses, fabric filter), 90, 686,689,690,704-710,802 advantages of, 705 air-to-cloth ratio, 706 efficiency of, 705, 710 maintenance, 707 operating costs, 705 pulse jet, 705, 709 reverse air, 704, 705 types of bags, 708 Balanced draft, 46, 75, 81, 91, 92, 187, 188,235, 314,317 Barometer, 170, 625 Bessemer process, 132 Blowdown system, 50, 364-369,415,417, 654-656,803 Blowoff tank, 369 Boiler bank, 16, 71, 81, 343 Boilers, 3, 5, 7, 27-123, 729, 740, 742, 746, 750, 757,802,808 air leakage in, 423 arches for, 69, 222, 223, 242 assembly of, 148-151 Boilers (Cont.): availability, 29 baffles, 38,43,47, 222,444,448 banking of, 237, 243, 260, 287, 301, 369, 802 blowdown, 50, 364, 415, 417, 654-656 blowoffline, 148,364 boilout,404,802 calculations for, 151-161 capacity, 151-161 carryover, 49, 140,331,413,606 caustic embrittlement, 414, 417, 418, 444, 446,802 circulation, 30-32, 87, 88,155,241,331 chemical cleaning of, 404, 438, 645, 686 cleanliness, 379, 441 condition evaluation, 445 control (see Combustion, control of; Control systems) corrosion in, 78, 129,413,416,420,446,450, 451,596,645,744,757-760 creep in, 446 cross drum, 40 design and construction of, 129-161 design considerations, 70, 71, 740 drums of, 16,32,40,50, 138-145, 446 efficiency of, 421 425, 695 electric, 38 erosion in, 80, 759 excess air for (see Excess air) expansion of, 46, 68, 71, 79, 129, 146, 149, 221,344,435 fire tube, 32-38,48,68, 139, 140, 149, 151, 221-223,340,412,444 fluidized bed boilers (see Fluidized bed boilers) foaming in, 413, 418, 429 furnace design considerations, 67 furnace volume, 154, 169, 222, 223, 278, 304 fusible plug, 338-340, 444 gauge connections to (see Gauges) heat recovery steam generator (HRSG), 22, 112, 116 heating surface, 151-155, 224 high temperature water (HTW), 47 horsepower, 151 ideal, 27 idle, 432 434 industrial, 3, 15, 77, 91, 445 694, 705, 806 inspection, 442 445 leaks, 419 maintenance, 15,410,419,420,434-442, 757-761 material used in, 129-133, 749, 759, 760 oil- and gas-fired, 12, 45, 289, 309 once through, 32, 78, 88 operation of, 309-313, 403-434, 757-761 811 812 Index Boilers (Cont.): packaged units, 44, 47-49, 78, 149,228, 309-313,807 priming in, 413, 418, 429 repairs to, 446-451 risers in, 87 riveting of, 139, 141,417 Scotch marine, 37 settings of, 28, 68, 221-224 startup, 403, 407 steam-water separation, 32, 42, 46, 49-53, 14() Stirling, 41, 72 stress in, 130 superheatersin,40,42-46,54_60, 71, 78, 146,148,154,446 support, 79, 145, 149,221 tube failure, 419, 429, 759 utility, 3, 9, 77, 91, 190, 261, 395, 445, 535, 595,691,693,705,809 water level in, 331-338, 343, 347, 411, 418, 428 water tube, 38-49,221,433,444,446 welding of, 138-145 Boiling, 29, 501 Bourdon pressure gauge, 340 Boyle's law of gases, 171, 802 Bridge wall, 222 British thermal unit (Btu), 3, 211, 802 Burners,5,68,264,265,276-282,286,293_308 control systems (see Combustion, control of) gas-fired, 303-308 inclined, 84 low excess air, 214 10w-NOx burners, 276-282, 293, 302, 306, 307,689 opposed firing, 87, 89 pressure type, 296 rotary, 293, 299 steam or air atomizing, 294 tilting, 58, 80 turn-down ratio, 68, 294 By-product fuels, 89, 208-211 bagasse, 209 black liquor, 209 municipal solid waste (see Municipal solid waste) sludges, 96, 210, 211 wood and bark, 208, 209 Calorimeter, 156, 181, 191, 202, 207 Carbon loss (see Unburned carbon loss) Carry~over, 49, 51, 53, 54, 140, 331, 413 Chemical energy, 1,27,211 Chemical reactions in combustion, 172-180 Cinder reinjection (see Fly ash reinjection) Circulation of boiler, 331 controlled,87 natural, 87 once through, 88 Circumferential joint, 35 Cleanliness of pLant, 379, 441 Clinker, 168, 198~5, 238, 25.4, 409, 423' Clinker grinder, 233, 237 ' Coal, 10-12, 188-200 air required for, 177-188 analysis of, 177, 178, 191 anthracite, 189, 190 Index Coal (Cont,): anthracite culm, 102 ash in, 189,191, 192, 199,224,262 bituminous, 190 bituminous waste, 103 classification of, 189 coke, 192,226,228,230 considerations for firing, 89 fixed carbon in, 191 formation of, 188, 191 free swelling index, 194, 236 fusion temperature of, 76, 192, 198, 224, 238 grindability, 197,283,805 handling of, 196 hard, 195 Hardgrove standard on grindability, 197 heating value of, 191, 199,253,274 impurities of, 189 lignite, 78, 189 moisture in, 191, 192, 195, 262 peat, 188, 189 proximate analysis of, 191, 807 size of, 196, 236, 242, 245, 253, 261, 262 soft, 175, 195, 222 spontaneous combustion, 199, 200 storage of, 199 sub-bituminous, 190 sulfur in, 78, 188, 190, 192, 199 tempering of, 196, 243 transportation of, 196 ultimate analysis, 192, 193 volatile matter in, 190, 191, 195, 223, 234, 262 weight of, 780 Code requirements, 129, 131, 137, 140-144, 151,192,289,308,334,338,351,372,447, 451,563,657 Coefficient of expansion, 661, 780 Combined cycle systems (cogeneration systems), 13,16,21,23,111-117,303,395 Combustion, 165-188, 212, 422, 432, 802 air requirements for, 5, 165, 176-188,4 39 chemical reactions in, 172-182 complete, 177, 222 control of, 211-217, 232, 240, 252, 258, 265, 274,286,289,292,304,308-313,408, 419 excess air in (see Excess air) ignition temperature, 166, 200 incomplete, 174, 177,211,424,689,806 perfect, 177 products of, 167, 807 spontaneous combustion, 199, 200 temperature required, 166 theoretical air required, 169, 180, 181 theory of, 169-182 time required for, 166 two-stage, 280, 302, 689 Combustion equipment, 197, 199,221-326 (See also Burners; Pulverized coal firing; Stokers) Composting, 729, 732, 733, 738, 740, 761 Compressive stress, 129 Condensate, 633, 645 Condensate polishing systems, 645-647 Condensation, 170, 568, 802 Condense~4-7,455,491,522,563,568-578, 596,600,611-616,618 air-cooled, 569, 572, 585, 615 auxiliaries for, 587-591 circulating water for, 575, 587, 591, 601, 611, 618 direct contact, 568 ejector for, 570, 571, 587, 590, 611, 624 expansion, 570, 572 fouling of, 611, 613 hot well of, 570, 571, 611, 613, 647 impact on plant efficiency, 600, 611 maintenance of, 613, 615 materials and construction, 573-576 operation of, 611-613 surface,569-572,587,590,600,611-615 Conduction,28,53,75,94,109,802 Continuous emission monitoring (CEM) system, 180,217,305,392-395,760 Control systems, 386-398 Convection, 28, 53, 75, 109, 154,803 Cooling pond, 577, 616, 617 Cooling towers, 7, 522, 569, 572, 576-587, 611, 615-622,686 design considerations, 585 fire protection, 586, 622 functions of, 576 maintenance of, 621 materials of construction, 587 mechanical draft, 577-584, 617-619, 621 natural draft (hyperbolic), 577, 578, 584-587, 621 operation of, 618-621 operating costs, 584, 618, 620, 621 types of, 578 water treatment for, 620 Corrosion of power plant equipment, 166, 176, 199, 205, 213, 410, 413 416, 420, 446, 450, 451,496,570,571,632,634,639,660,664, 744,757-760 Creep, 132,446 Cyclone steam separators (see Steam separators) , Dampers, 55,59,243,301, 316,320,322 Deaerators, 414, 417, 455, 632-644, 803 Degrees of superheat, 157, 803 Demineralizer, 414, 645-646, 651, 803 Density, 492, 501, 803 Desuperheater (see Attemperator) Dew point, 66, 199, 205, 708, 803 Downcomers, 41, 87, 803 Draft,183-188,313-314,379,803 Draft gauge, 183, 386 Draft loss, 313, 379, 803 Dry pipe, 36, 49-51, 140 Dry scrubber for acid gas removal (see Sulfur dioxide scrubber systems) Ductility of metal, 131, 132 Dulong's formula, 181 Dust collector: baghouses (see Bag filterhouses) electrostatic (see Electrostatic precipitator) mechanical, 79, 89, 689, 690, 695, 697, 707 multiclone, 104, 105, 695 813 Economizer, 7, 16,41,60-63, 153, 154,455, 570,804 Efficiency of joint or tube ligament, 138 Efficiency of steam plant, 4, 5, 10, 15, 63, 66, 71,90,111,115,121,158,165,206,211, 233,352,274,525,569,804,808 Elastic limit, 131, 136 Electric generator, 4, 7, 551, 565-568, 575, 595, 596 Electricity production, 1,4,7, 10,54, 115, 116, 303,522,555,566,575,595,685,732 Electrostatic precipitators, 90, 686, 689, 690, 697-703,804 ash removal, 700, 703 collecting plates, 697, 699, 700 discharge electrodes, 697, 698, 700 efficiency of, 697, 702 rapping system, 697, 700-703 resistivity of ash, 698 rigid frame, 698-703 weighted wire, 698, 702 Elongation, 131 Emission limits, 691-695 Emission sources, 686 Energy, forms of, 1,3,27, 160, 170,517, 732, 804 Enthalpy, 155-161,804 Environmental control systems, 4, 7, 91, 316, 685-725 regulations for, 685, 690-695 removal requirements for, 691-695 (See also Nitrogen oxide control; Particulate collector; Sulfur dioxide scrubber systerns) Evaporator, 415, 652-654 Excess air, 66, 81, 87, 168, 169, 179-182,206, 208,213,224,258,302,422,423,750,757, 804 Fabric filter (see Bag filterhouses) Factor of safety in boilers, 136 Fans (mechanical draft), 317-325 bearings for, 323 characteristics of, 318 control of, 322 horsepower of, 320-322 maintenance of, 323 noise from, 325 pressure of, 319 silencers, 325 Feedwater: analysis of, 412-419 hardness of, 412, 629 heating of, 5, 597, 629-645 impurities in, 15, 51, 629 pumping of, 491 quality of, 15,49-51, 569, 62~1 Feedwater heaters, 7, 455, 491, 51', 630-645 closed, 630-632 functions of, 630 open (see Deaerators) operation and maintem Feedwater regulators, 49, Fiber optics, 336, 338 Fire tube boilers (see Boll ''70 814 Index Index Fission energy (nuclear), 2, 3, 117-121 Flame impingement, 68, 74, 286, 300, 306, 435, 444,449,804 Flame safety system, 282, 285, 286, 289, 299, 300, 305, 311, 430 Flue gas, analysis of, 179-181 gas by-pass, 59 desulfurization of (see Sulfur dioxide scrubher systems) recirculation, 59, 86 Flues and ~ucts, 326 Fluidized 'bed boilers, 18-21, 89, 92-110, 199, 211,261,403,695,697,710,741,805 advantages of, 20, 93, 95 bed drain, 94, 98,104-108,428 bedlevel,98,109,427 bed material, 97, 101, 108, 426 bed temperature of, 94-101, 105, 109, 110, 427,428 bubbling fluid bed (BFB), 20, 94-98, 109, 211, 427 circulating fluid bed (CFB), 20, 94-96, 98-110,426 coal size of, 94, 96 cold cyclone separator, 104, 107 control of NO" 19,20,92,95,97, 101, 104, 105,108,689,723 control ofS02, 19, 20, 93, 95, 97, 98,108,688 freeboard area, 96, 109, 426 fuel flexibility, 95, 425 heat transfer of, 94, 99, 109 hot cyclone separator, 101, 104, 107 impact separator, 104 in-bed heat transfer surface, 98, 109, 110 limestone as sulfur sorbent, 93, 95, 97, 101, 104, 108 operating characteristics, 425-428 particle collection, 98, 99, 104-107,697 vs pulverized coal and stoker firing, 93 recycle system, 98-107 sand as bed material, 104, 105, 108 sludge burning, 211 solid separation system, 104-107 water-cooled cyclone separator, 104, 107 Fly ash reinjection, 43, 70, 71, 89, 245, 251, 261, 695 Forced draft (FD) fan, 5, 91, 185, 235, 244, 300, 314,317 Fossil fuels, 1,7,9, 10 Friction, 492, 494 Fuel17 bark,89,208,698 by-product, 77,208-211 heating value of, 92, 181, 191 waste, 77, 254, 523, 596 Fuel handling system, Fueloil,200-206,289-302 advantages and disadvantages of, 203, 297 ash content of, 204, 205 atomization of, 201, 204, 293, 294 classification·M;.201, 203, 204 fire point of, 202 flash point of, 202 heating of, 202-204, 214, 289, 299 heating value of, 202 • , Fuel oil (Cant.): impurities in, 202, 205, 298, 300 maintenance, 302 NO control, 302 ope~ating boiler with, 206, 299 sludge in, 205 specific gravity of, 201, 202 storage of, 289 sulfur in, 205 transportation of, 289, 298 viscosity of, 202, 203, 292 Furnaces: cyclone firing, 77, 224, 261 design considerations, 67 dry bottom, 76 heat release in, 72, 223, 278, 805 heating surface, 67 refractory, 70, 72, 205, 223, 224, 278, 443, 449,450 turbo, 82 water-cooled, 67-73, 223, 278, 450 wet bottom (slag tap furnace), 76,224,282,409 Fusion energy, Gas, 206-208,302-309 analysis of, 207 blast furnace, 208, 209, 302 classification of, 207 coke oven, 208, 209, 302 combustion of, 208 heating value of, 208, 304 maintenance, 306 methane, 175,206,208, 737, 744 natural, 206, 302 NO, control, 306 producer, 2006, 208 refinery, 210, 302 transportation of, 302 Gas analyzers, 214 Gas laws, 171, 802 Gas turbines, 16,21,22, 111-116,206,303,395 Gauge: correction for water column, 342 draft, 386 pressure,340-342,386,625 vacuum, 625 water level, 331-338, 387, 431 Geometric formulas, 781, 782 Graphitization, 132 Gravimetric feeders, 105,274-276 Grease, 674 Gypsum, 686,688,691, 710, 714 Hand-fired furnaces, 167, 183, 198, 199, 223-227,409 Hardgrove standard on coal grindability, 197, 805 Heat absorption in boiler, 16,28,54, 75, 80 Heat loss, 60, 158,166, 182, 197,211,212,422, 425,439,576,654,664 Heat rate, 523 Heat recovery equipment, 60-66, 110, 185,316, 422 Heat sources of, Heating surface, 67, 76, 151-155, 278 Heat transfer, 3, 53, 71, 94, 109, 154, 159, 410, 446,448 Horsepower, 806 of boiler, 151 of fan, 320-322,619 of Pump, 503 Humidity, relative, 584, 617, 621, 664 Hydrocarbons, 167, 195,222 Hydrostatic test, 136,150,364,404,430,445,806 Hydraulics, 492 Ice, specific heat of, 780 Ignition arches, 223 Incinerators for burning waste, 729, 741 Independent Power Producers (IPPs), 9, 19, 77, 523,595 Induced draft (ID) fan, 7, 91, 185, 236, 253, 300, 314,317,430,440,695 Instruments, 386-398, 408, 421, 605 Insulation and lagging, 425, 664, 665 Ions (anions and cations), 414, 646, 648, 651 Kilowatts (kW), 523, 806 Kilowatt-hour (kWh), 806 Landfills, 210, 211, 686, 691, 714, 729, 730, 733, 736 Lighters for burners, 282, 286, 299, 305 Limestone, 93, 688, 711 Loads on boilers, 146 Longitudinal joint, 35 Lubricants, 674-681 Manholes, 147 Manometers, 340 Mass burning of MSW, 741-750 Matter, forms of, 169 Material recovery facilities (MRFs), 734, 764-769 Measurement, tables of, 775-780 Melting, 169 • Membrane water walls, 49, 71, 75, 149,450 Metaltemperature,66,343,410,420, 759 Methane recovery, 741 Micrometer (see Microns) Micromhos, 652 Microns, 90, 693,695 Microsiemens, 652 Moisture, content of steam, 4, 156 Molecular weight, 172, 173 Mollier chart for steam, 784, 794 Municipal solid waste (MSW), 72, 89, 165, 393, 523,596,698,715,722,729-740,761_763, 806 combustion of, 731, 734, 735, 741, 742, 751 composition of, 737-740 energy recovery technologies, 741, 742 heating value of, 735, 738, 739, 740 disposal, 732, 733 potential energy from, 735 processing of, 751 Iuantityof, 731, 733, 735 1V0rldmanagement, 735 815 Natural gas, 1,7, 10,21,201,206 Natural gas firing, 7, 21, 212 Net plant heat rate, 523 Net positive suction head (see Pumps) Nitrogen in air, 176, 724 Nitrogen oxide (NO) control, 4, 19, 20, 23, 77, 92,95,97,176,214,252,256,276,279, 302,306,686,689,723_725 selective catalytic reduction (SCR), 23, 97, 689,725 selective noncatalytic reduction (SNCR), 97, 689 Noise pollution, 325, 685 Noncondensable gases, 570, 571, 587, 590, 611, 625,632 Nuclear power, 10, 11, 117-123, 158 Oil (see Fuel oil) Oil cups, 675 Open hearth process, 132 Operating permit, 685 Orsat gas analyzer, 180, 214, 305, 394 Overfire air, 43, 69, 71, 90, 105, 227, 231, 234, 240,244,252,256,258,318,326,724,807 Oxidation, 166 Oxygen in air, 176-182 Particulate collector, 7,251,318,689,695_710, 744 Particulate emissions, 89, 90, 251, 686, 689, 695,697 Particulate removal: efficiency, 693 requirements, 691, 694 Parts per million (ppm), 643 Penetrometer (for X-ray), 144 pH value, 620 Pipeline separators and strainers, 671 ~ping,373,656-665 expansion of, 656, 660-663 insulation of, 664, 665 pressure drop in, 656, 661 schedule numbers for, 657 sizing of, 656 support of, 663 vs tubing, 659 velocities in, 656 vibration in, 663 Pollution: air (see Environmental control systems) thermal (heat), 576, 686 Potential energy, 1, 3, 735 Power plant output, 2, 4, 522 Power plant systems, 2, Precipitators (see Electrostatic precipitators)' Pressure, 492 absolute, 155, 170 atmospheric, 155, 170,501,625 below atmospheric (vacuum), 625 critical, 31, 32, 803 design, 803 drop, 807 measurement of, 170, 340 subcritical, 50 Pressurized furnace, 46, 75, 78-81,91, 187,317 Index 816 Primary air fan, 5, 264, 265" 268, 272, 288, 318 Process steam, 111 Pulverized coal firing, 5, 7, 9, 12,66,70,73,76, 82,84,86,90,110,111,195-199,224, 261-289,391,409,431,697 advantages and disadvantages, 90, 284 burners for, 264, 265, 276-28~ components of, 263 design requirements, 264 fineness of coal, 264 firing procedures for, 282-289 influences on firing, 262 maintenance, 287 operating requirements, 289, 39-! vs stoker firing, 90 Pulverizer feeders, 263, 273-276 " Pulverizer mills, 264-273 Punips, 292,301,455-512,587,624,625 bearings for, 488, 500, 508, 512 boiler feed, 455, 479, 490, 570, 630, 631, 636 calculations for, 500 cavitation, 493 centrifugal,456,479-491,494,500, 508,587 588 circulating water, 455, 577, 587, 611, 624 classification of, 456 considerations for selection, 495 condensate,455,479,491,570, 587,589,611, 624,631,646 comparison of, 491 displacement, 456, 475 duplex, 460-470, 473,505-508 dynamic, 456 fluids and pumping, 492 foot valves for, 469, 495, 498 head on, 457,475,485,489,492,495,500, 805 injector (jet pump), 457-460 installation of, 496-500 lubrication, 508, 511 maintenance of, 506, 512 metering pump, 470-473 net positive suction head (NPSH), 475, 493, 494 noise and vibration in, 493 operation of, 493-500 packing in, 5090608 , performanoe '!bf, 501-506 power plant requirements, 455 power pump, 470-473 power requirements, 504 priming of, 469, 495, 498, 624 reciprocating, 292, 456, 500, 506, 509 rotary, 292, 456, 475-479, 494, 540 slurries, 496 steam turbine drive, 455 strainer for, 469, 498, 624 testing and calculations for, 500-506 use of, 455 vacuum,473-475,499,587,589,624 Pyrolysis, 741 Pyrometer, 343 ''-Quality of steam, 156, 157 •• ' Radiation: nuclear, 117, 121 Radiation (Cont.): thermal, 28, 53, 60, 75, 109, 154 , 234, 239, 807 Radiographs (see X-ray tests) Rankine cycle, Recycling of materials, 729, 730, 732-735, 740, 751,761-772 Refuse derived fuel (RDF), 72, 89, 223, 244, 254, 731,739,741,742,750-758 Reheater, 4, 56, 58, 146, 154, 158, 358, 446, 535, 561,596,599,807 Relief valves, 351 Resistivity, 698, 705 Safety precautions for oil and gas firing, 308 Safety valves, 350-364, 404-406, 431, 807 Saturation temperature, 47, 54, 155-158, 343 Scale in boilers, 412, 416, 424, 436, 629, 648 Shear stress, 130 Slagging, 70, 73, 77, 169, 192, 198, 199,261, 262,282,286,379,410,439,757 Sludges, 96,210,211,686,690 Smoke,223,231,326,423,808 Solar energy, Solid waste (see Municipal solid waste) Sootblowers, 64, 199,236,374-380,410,424, 439,444,759 Specific gravity, 492, 495, 675 Specific heat, 214, 780 Specific volume (steam and water), 155 Specific weight (density), 491 Spray pond, 577, 616, 617 Stacks, 185,313-317,699 Steam: condensing of, 568, 569 fundamentals of generating, 29 moisture·free (dry), 51, 56, 155 quality of, 156, 157 reheated,4,15,56,58,78,158,526,535 saturated,50, 54, 77, 155-158,807 superheated,4,54-60,77,157,158,535, 808 use of, wet, 156, 809 Steam coil air heater, 66 Steam engine, 517 Steam generator (see Boilere) Steam jete, 325 I Steam piping, 373 Steam-plant cycle, 4, 7, 10, 15 Stearn separators, 49-53, 81 Steam system cycles for utilities, 10, 595 Steam tables and charts, 155, 625, 783, 795 Steam traps, 665-671 Steel: manufacturing of, 132 properties of, 780 strength of, 129-138 Stoichiometric ratio, 172 Stokers, 66, 110, 199,224,227-261,707,743, 744,754,808 advantages and disadvantages, 90, 249 burning rate, 228 chain grate, 69, 223, 238-240 coal distribution, 245, 254, 256 dead plate, 226 features of, 227 ... Chapter xl Steam and Its Importance The Use of Steam The Steam- Plant Cycle The Power Plant Utility Boilers for Electric Power 1.4.1 Coal-Fired Boilers 1.4.2 011 and Gas-Fired Boilers 1.4.3 Steam Considerations... power plant equipment, this book would not have been possible I am sincerely grateful to all who assisted me in this project-the seventh edition of Steam Plant Operation Thomas F Lammers Steam. .. and condensate, steam, environmental control systems, and the control systems that are necessary for a safe, reliable, and efficiently run power plant The seventh edition of Steam- Plant Operation