Identifier: appliedthermodyn01enni (find matches)
Title: Applied thermodynamics for engineers
Year: 1913 (1910s)
Authors: Ennis, William Duane, 1877-
Subjects: Thermodynamics
Publisher: New York, Van Nostrand
Contributing Library: The Library of Congress
Digitizing Sponsor: The Library of Congress

View Book Page: Book Viewer
About This Book: Catalog Entry
View All Images: All Images From Book
Click here to view book online to see this illustration in context in a browseable online version of this book.

Text Appearing Before Image:
388 APPLIED THERMODYNAMICS ins; ^. This is a horizontal single-stage impulse turbine with a single wheel. Itslotative speed is consequently high; in small units, it reaches 30,000 r. p. m. It is
Text Appearing After Image:
built principally in small sizes, from 5 to 300 h.p. The nozzles make anglesof 20° with the plane of the wheel; the buckets are symmetrical, and their angles DE LAVAL TURBINE 389 range from 32° to 36°, increasing with the size of the unit. For these proportions,tlie most efficient values of u would be about 950 and 2100 for absolute steam veloci-ties of 2000 and 4400 feet per second, respectively; in practice, these speeds arenot attained, u ranging from 500 to 1400 feet per second, according to the size.The high rotative speeds require the use of gearing for most applications. Thehelical gears used are quiet, and being cut right- and left-hand respectively theypractically eliminate end thrust on the shaft. The speed is usually reduced in theproportion of 1 to 10. The high rotative speeds also prevent satisfactory balanc-ing, and the shaft is, therefore, made flexible ; for » 5-hp. turbine, it is only finch in diameter. The bearings A, / are also arranged so as to permit of somemo

Note About Images