Page 254 - Steam Turbines Design, Applications, and Rerating
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Reaction vs. Impulse Type Steam Turbines 233
(a)
Figure 12.12 Drainage channels
inside the reaction turbine: (a)
in large turbines; (b) in small
turbines. (Asea Brown-Boveri,
Baden, Switzerland)
(b)
12.7 Maintenance
The structural differences mean that times between overhauls can be
longer for an impulse turbine. This is primarily due to the generally
heavier diaphragms on which the fixed blades are mounted.
12.8 Design Features of Modern
Reaction Turbines
It has already been mentioned that the reliability of a steam turbine
today depends only to a small extent on its basic constructional philos-
ophy. Machines that satisfy the design, operational, and reliability
expectations of modern user facilities are available from several man-
ufacturers. The main features of these machines can be listed briefly as
follows (Fig. 12.13):
