Overview:
This book, published in 1919, provides a comprehensive overview of steam generation and its applications. It begins with a captivating historical journey, tracing the evolution of steam engines from Hero of Alexandria’s early inventions to James Watt’s revolutionary contributions.
The text then delves into the crucial requirements of a “perfect” steam boiler, highlighting the importance of efficient circulation, durability, and safety. This sets the stage for a detailed exploration of the Babcock & Wilcox water-tube boiler, emphasizing its design principles and advantages over other boiler types.
Key Findings:
- Importance of efficient circulation: The text stresses the significance of proper water circulation within a boiler for optimal efficiency, durability, and safety.
- Babcock & Wilcox boiler’s superiority: The book emphasizes the Babcock & Wilcox boiler’s superior performance in terms of safety, economy, capacity, and quick steaming.
- Benefits of superheated steam: It thoroughly details the numerous advantages of superheated steam, including increased engine efficiency, reduced condensation, and decreased turbine blade erosion.
Learning:
- Understanding the History of Steam: Readers will gain insight into the evolution of steam power technology and the contributions of key figures like Hero of Alexandria, Savery, Newcomen, and Watt.
- The Theory of Steam Making: The book explains the process of water conversion into steam, exploring concepts like sensible and latent heat, and the critical points of phase change.
- The Importance of Efficient Circulation: Readers will learn why proper water circulation is essential for a boiler’s performance and safety.
- The Babcock & Wilcox Boiler Design: The text details the design features and benefits of the Babcock & Wilcox boiler, including its unique header system and suspension method.
- The Advantages of Superheated Steam: Readers will gain knowledge about superheated steam’s benefits in prime movers, including increased efficiency, reduced condensation, and decreased turbine blade erosion.
Historical Context: The book was published in 1919, at the tail end of World War I and during a period of rapid industrialization. This context is evident in the text’s emphasis on high efficiency and capacity in steam generation, reflecting the growing demand for power in manufacturing, transportation, and other industries.
Facts:
- Hero of Alexandria (150 BC): Described steam-powered devices for raising water and creating rotary motion.
- Edward Somerset (1663): Proposed, if not built, the first useful steam engine.
- Denys Papin (1680): Invented the first safety valve for steam boilers.
- Thomas Savery (1699): Built and exhibited the first commercially successful steam engine.
- Thomas Newcomen (1690): Developed the first cylinder and piston steam engine, known as the atmospheric engine.
- James Watt (1769): Patented significant improvements to the steam engine, including a separate condenser and the use of steam expansively.
- Richard Trevithick (1800): Introduced high-pressure steam engines.
- Oliver Evans (1800): Promoted the use of high-pressure steam in the United States.
- John Blakey (1766): Built the first water-tube boiler.
- James Rumsey (1788): Successfully used water-tube boilers for steam navigation.
- Jacob Woolf: Designed a boiler with large horizontal tubes connected to a drum above.
- Julius Griffith (1821): Built the first sectional water-tube boiler.
- Joseph Eve (1825): Constructed the first sectional water-tube boiler with well-defined circulation.
- Goldsworthy Gurney (1826): Built boilers for his steam carriages, using U-shaped tubes.
- Stephen Wilcox (1856): Pioneered the use of inclined water tubes connecting water spaces.
- The Babcock & Wilcox boiler (1867): Introduced by George H. Babcock and Stephen Wilcox, emphasizing safety in design.
- The “wagon boiler” (1785): Introduced by Boulton and Watt, known for its shape.
- The “dry pipe” in the Babcock & Wilcox boiler: Primarily functions as a steam collecting pipe, not as a restrictor against priming.
- The “Webster” furnace: A patented furnace design offering flexibility for different fuels and stokers.
Statistics:
- A cubic foot of heated water at 60-70 pounds pressure: Has the same energy as one pound of gunpowder.
- Plate thickness required for a 60-inch diameter cylinder: 0.5 inches for 200 pounds gauge pressure.
- Safe working pressure for a No. 10 gauge tube: 870 pounds per square inch.
- A shell boiler at 100 pounds pressure: Can be projected up to 3.5 miles in an explosion.
- An incrustation of one-eighth inch: Can cause a loss of 25 percent in boiler efficiency.
- A 240 horse-power Babcock & Wilcox boiler: Can be forced to 32 times its rated power.
- Babcock & Wilcox boilers operating in large plants: Can be run at 200-225 percent of their rated capacity and sometimes at 300 percent during peak loads.
- The Babcock & Wilcox Company: Has sold over 9,900,000 horsepower of boilers worldwide.
- The specific heat of water: Varies with temperature, from 0.9979 at 130 degrees Fahrenheit to 1.0101 at 100 degrees Fahrenheit.
- Water at 39.2 degrees Fahrenheit: Has a weight of 62.43 pounds per cubic foot.
- One pound of coal: Can generate 14,500 British thermal units (B.t.u.) during combustion into carbon dioxide.
- The calorific value of carbon: 14,600 B.t.u. per pound.
- The calorific value of hydrogen: 62,000 B.t.u. per pound.
- The calorific value of sulphur: 4050 B.t.u. per pound.
- A 100 horse-power boiler: Can deposit 300 pounds of solid matter per month from water containing 7 grains per gallon of impurities.
- The theoretical amount of air required per pound of fuel: 34.56 (C/3 + (H-O/8) + S/8) pounds.
- The “Idalia” steam yacht tests (1909): Showed a 15.3 percent saving in steam consumption and 10 percent saving in heat consumption with 105 degrees of superheat.
- The water rate of a large steam turbine: Is reduced by 1 percent for every 12 degrees of superheat up to 200 degrees Fahrenheit.
Terms:
- B.t.u. (British thermal unit): A unit of energy used to measure heat, defined as the amount of heat required to raise the temperature of one pound of water one degree Fahrenheit at 62 degrees Fahrenheit.
- Calorie: The metric unit of energy used to measure heat, defined as the amount of heat required to raise the temperature of one kilogram of water one degree Celsius at 15 degrees Celsius.
- Specific Heat: The amount of heat required to raise the temperature of one unit of mass of a substance by one degree.
- Sensible Heat: The heat that causes a change in temperature of a substance.
- Latent Heat: The heat absorbed or released during a phase change, such as melting, freezing, boiling, or condensing, without a change in temperature.
- Ebullition: The process of boiling, where a liquid changes to a vapor.
- Saturated Steam: Steam that is in equilibrium with liquid water at the same temperature and pressure.
- Superheated Steam: Steam that is heated above the saturation temperature at the corresponding pressure.
- Quality of Steam: The percentage by weight of steam in a mixture of steam and water.
- Factor of Evaporation: A correction factor used to compare boiler performance under different conditions of steam pressure and feed water temperature.
- Combustion: The process of burning, which involves the rapid chemical reaction between a substance and oxygen, releasing heat and light.
- Kindling Point: The minimum temperature at which a substance will ignite and burn.
Examples:
- Hero’s engine (circa 150 BC): A steam-powered device with a hollow sphere rotating due to the reaction of steam escaping through pipes, demonstrating the concept of a steam turbine.
- Savery’s engine (1699): Used two copper receivers alternately filled with water and then forced out by steam pressure, demonstrating early steam pumping technology.
- Newcomen’s atmospheric engine (1690): Utilized steam to raise a piston in a cylinder, followed by condensation to create a vacuum and allow atmospheric pressure to force the piston down, providing power for pumping.
- Watt’s improvements to the steam engine (1769): Introduced a separate condenser to reduce steam waste and the use of steam expansively to improve efficiency.
- The “Montana” ship (1890s): A notorious example of boiler failure due to improper circulation, highlighting the importance of this design principle.
- The “Idalia” steam yacht tests (1909): Demonstrated the significant fuel savings achievable through superheated steam by comparing steam consumption with saturated and superheated steam.
- The use of boiler compounds: Illustrates a common approach to prevent scale formation in boilers, using chemicals like soda and tannic substances.
- The Orsat apparatus: A widely used device for analyzing flue gases, providing insights into combustion efficiency and heat losses.
- Secondary combustion: Demonstrates the phenomenon of incomplete combustion where carbon monoxide ignites with air after leaving the furnace, leading to efficiency losses.
Conclusion: “Steam, Its Generation and Use” by Babcock & Wilcox, published in 1919, provides a valuable resource for understanding the theory and practice of steam generation. The text highlights the crucial role of efficient circulation in boiler design, emphasizing the Babcock & Wilcox boiler’s superior performance.
Furthermore, the book emphasizes the advantages of superheated steam, showcasing its benefits in increasing engine efficiency, reducing condensation, and mitigating turbine blade erosion. This historical overview and detailed technical analysis offer a thorough foundation for those seeking to grasp the fundamental principles of steam technology.