File:The steam-engine and other heat-motors (1909) (14586621269).jpg

Identifier: steamengineother00crei (find matches)
Title: The steam-engine and other heat-motors
Year: 1909 (1900s)
Authors: Creighton, William Henry Paul, 1859-
Subjects: Steam-engines Heat-engines
Publisher: New York, J. Wiley & sons (etc., etc.)
Contributing Library: The Library of Congress
Digitizing Sponsor: The Library of Congress

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of steam per second SUPERHEATED STEAM AND STEAM-TURBINES. 475 The reaction work due to the increase of relative velocityfrom Vi to v2 is Km = v22—Vi2 29 The kinetic energy due to the absolute velocity of the steam V22at exit from the first row of revolving blades is -~-. Hence The net work done in the first stage is K=K8+Km- 2g- The total work done in the moving blades is Kt=K8+Kr The fraction called the degree of reaction is-^. In the second stage, if Vx is the absolute velocity of entranceto the stationary row of blades and V2 the absolute velocity atexit from the revolving row, and if the relative velocity in the Vla=550- vu =36(T Stage A V Stage B StageC U=250 >^ V2a=500-^ r2a=690 ;; ^=550^. tt = 250 /vu = 360 tt=250 S VaTSQQ^ \. V 26=690 yy U=250 I V^-550-^ rlc=360 14~250V2=500 U = 25Q Fig. 251. second row is increased from ^i to v2 as before, the net work doi.ewill be (Fig. 251) Vt2~V22 v22-Vl2 2g 2g 476 THE STEAM-ENGINE AND OTHER HEAT-MOTORS. Condenser or^Exhaust Pressure
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Fig. 252.—Diagrammatic Sketch of Hamilton-Holzwarth Turbines. SUPERHEATED STEAM AXD STEAM-TURBINES. 477 If .there are (n — 1) similar stages the total work for n stages,including the first, will be V12 r22 The Hamilton-Holzwarth turbine is, like the Parsons tur-bine, a full-stroke turbine; that is, the steam flows in one con-tinuous belt or veil in screw line through the turbine. The steam works only by impact, not by reaction, thus avoid-ing the balancing pistons of Parsons. In the stationary blades, which reach up to the shaft in orderto restrict the dangerous clearance to a minimum, the steamhas a chance to expand and reach a certain velocity and a cer-tain direction in which it impinges the next running-wheel. The absolute velocities of the steam in this turbine are higherthan in the Parsons turbine, but they are lower than in the Curtisand much lower than in the De Laval. In this turbine the steamis expanded in every stationary blade down to a certain pressureand accelerated

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