Handbook of Turbomachinery Second Edition Revised - Ventech!

casing and flowed axially in opposite directions through two groups of
turbine wheels, each containing 14 consecutive wheels. The design was
intended to subdivide the pressure drop among the stages and reduce the
required rpm. An early experimental turbine, producing 0.746 kW (1.0 hp),
with 7.6-cm (3-in.) wheels operated at 17,000 rpm. In 1887 Parsons designed
a compound turbine with a high-pressure and a low-pressure turbine
mounted on the same shaft. Parsons went on to develop a radial-flow
reaction turbine and a condensing turbine. The condensing turbine,
developed only seven years after Parson’s initial turbine, was more efficient
than steam engines of the time, which had seen over 200 years of
development. The rights to manufacture the Parsons reaction turbines
were acquired by Westinghouse in 1895 (Fig. 4). Allis-Chalmers also
acquired rights to manufacture the Parsons design. The first power station
to produce electricity from a steam turbine was in 1888 in a Newcastleupon-Tyne,
England, power station using a Parsons generating set.
The improvement of design, operation, and efficiency continues today
and makes interesting historical reading. For example, standardization to
1,800- and 3,600-rpm machines (from a variety of speeds—720, 750, 1,200,
1,500, and 1,800 rpm) occurred in North America when 25 Hz power
stopped being used by utilities and the frequency was standardized to 60 Hz.
Figure 4 500-KW reaction steam turbine (1900).
Copyright © 2003 Marcel Dekker, Inc.