All About Engines
Forfatter: Edward Cressy
År: 1918
Forlag: Cassell and Company, LTD
Sted: London, New York, Toronto and Melbourne
Sider: 352
UDK: 621 1
With a coloured Frontispiece, and 182 halftone Illustrations and Diagrams.
Søgning i bogen
Den bedste måde at søge i bogen er ved at downloade PDF'en og søge i den.
Derved får du fremhævet ordene visuelt direkte på billedet af siden.
Digitaliseret bog
Bogens tekst er maskinlæst, så der kan være en del fejl og mangler.
138 All About Engines
on the piston and decreases the net effective pressure,
tending to drive it forward. Further, the pump
encourages the expansion of the escaping steam, lowers
the back pressure, reduces the temperature, and there-
fore causes condensation to proceed more rapidly.
Whether a jet or surface
condenser is used to-day
depends upon the amount
of good water available for
boiler feeding. If this is
plentiful then there is no
disadvantage in mixing the
i
v
Fig. 84.—Combined jet condenser and air pump
cooling water with the exhaust steam, because this
will not be needed for the boiler, and even an inferior
quality of water may be used for cooling. If, on
the other hand, good water is so scarce that the
exhaust steam must be returned to the boiler, then
it is essential that a surface condenser be employed.
A simple form of jet condenser, combined with
an air pump, is shown in Fig. 84. This is fixed