ABSTRACT
Burners for industrial and utility boilers form a large class of combustion devices designed to ef…ciently convert the chemical energy of the fuel into heat within the space provided by a boiler radiant section that is also referred to as the furnace. Further heat absorption occurs in the convection section. The combination of the radiant section and convection section substantially de…nes the boiler. Most modern boilers with burners as
a speci…c part of the system were developed predominantly over the last century, whereas earlier boilers were …ring fuels such as coal or wood on a grate placed under the steam-and water-carrying tubes in an enclosed space with some rudimentary means of combustion process intensi…cation. The best legendary book on boilers with over 40 editions is published by the Babcock & Wilcox Company and is considered a bible for the boiler industry.1 This book gives an excellent overview of boilers with an emphasis on utility boilers, but goes very little into the more speci…c …eld of burners and especially
Vladimir Lifshits
CONTENTS
3.1Introduction..................................................................................................................................................................... 57 3.2Burner Design Fundamentals....................................................................................................................................... 58 3.3Techniques for Reducing NOx Formation.................................................................................................................. 60
3.3.1Flue-Gas Recirculation and Injection of Steam into the Flame.................................................................... 61 3.3.2Air Staging........................................................................................................................................................... 63 3.3.3Fuel Staging......................................................................................................................................................... 64 3.3.4Lean Premixed Combustion.............................................................................................................................. 64 3.3.5Furnace Gas Circulation and Combining Different Techniques................................................................. 66
3.4Burners for Package Boilers........................................................................................................................................... 66 3.4.1Conventional Round Burners and Burners with Air Staging...................................................................... 67 3.4.2Burners with Fuel Staging................................................................................................................................. 69 3.4.3Burners with Partial Lean Premixed Combustion........................................................................................ 70 3.4.4Premixed Burners............................................................................................................................................... 71 3.4.5Burners for Low Heating Value Gaseous Fuels and Fuels with Highly Variable Composition............. 73 3.4.6Oil Atomizers for Package Boilers.................................................................................................................... 75
3.5Burners for Enhanced Oil Recovery Boilers............................................................................................................... 76 3.6Burners for Multiple Burner Process Steam Field-Erected Boilers.......................................................................... 78 3.7Gas and Oil Burners for Utility Boilers....................................................................................................................... 80
3.7.1Combustion Systems for Oil and Gas Wall-Fired Utility Boilers................................................................ 80 3.7.1.1NOx Reduction Techniques in Wall-Fired Utility Boilers.............................................................. 81 3.7.1.2Burners for Wall-Fired Utility Boilers............................................................................................... 84
3.7.2Combustion Systems for Corner- Fired (T-Fired) Boilers............................................................................... 84 3.7.3Oil Atomizers for Utility Burners..................................................................................................................... 86
3.8Specialized Burners........................................................................................................................................................ 88 3.8.1Warm-Up Burners............................................................................................................................................... 88 3.8.2Flue-Gas Reheat Burners................................................................................................................................... 88
3.9Summary.......................................................................................................................................................................... 89 References.................................................................................................................................................................................. 90
the modern gas-and oil-…red burners that are a focus of this chapter. Another very diverse book on the subject of industrial combustion published in 2001 gives a good overview of combustion technologies for boilers at that time.2
