Improvements in the Regulation and Expansion of Steam in Steam Turbines.
Year: 1893

page_text: Date of Application, 30th Dec., 1893
Complete Specification Lefi. 1st Oct., 1894-Accepted, 3rd Nov., 1894
Improvements in the Regulation and Expansion of Steam in
Steam Turbines.
I, JOHN SMITH RAWORTH, of 24 Kirkstall Road, Streatham, in the County
of Surrey, Engineer, do hereby declare the nature of this invention to be as
follows:-
This invention has for object to regulate the speed of steam turbines and also
the degree of expansion of the steam used in such turbines.
For these purposes I construct a steam turbine with several steam nozzles so that
several jets of steam can be caused to act upon one or more bucket wheels with
which the turbine is provided. For the purpose of regulating the speed of the said
wheel or wheels, the passage of steam through the said nozzles is controlled by
means of a valve or valves under the control of a governor, the arrangement being
such as to cut off one or more of the steam jets in succession as the load decreases
and to turn them on as the load increases.
For the purpose of obtaining an economical expansion of the steam used in steam
turbines, whether working with or without the regulating apparatus described
above, the steam passing through the main duct is caused to enter and expand into
or within several nozzles, the number and cross sectional areas of which are arranged
to suit the increasing volume due to the diminishing pressure, and the increasing
velocity of the steam at each point in its path of efflux.
Dated this 30th day of December 1893.
W. LLOYD WISE,
46, Lincoln's Inn Fields, London, W.C., Chartered Patent Agent.
COMPLETE SPECIFICATION.
Improvements in the Regulation and Expansion of Steam in
Steam Turbines.
I, JonN SMITH RAWORTH, of 24 Kirkstall Road, Streatham, in the County
of Surrey, Engineer, do hereby declare the nature of this invention and in what
manner the same is to be performed to be particularly described and ascertained
in and by the following statement :-
This invention has for object to regulate the speed of steam turbines, and also
the degree of expansion of the steam used in such turbines.
For these purposes I construct a steam turbine with several steam nozzles so
that several jets of steam can be caused to act upon one or more bucket wheels
with which the turbine is provided. For the purpose of regulating the speed of
the said wheel or wheels, the passage of steam through the said nozzles is controlled
by means of a valve or valves under the control of a governor, the arrangement
being such as to cut off one or more of the steam jets, or compound steam jets, in
succession as the load decreases and to turn them on as the load increases.
In the accompanying drawings,
Fig. 1 is a diagrammatic view showing so much of a steam turbine as is necessary
to illustrate this part of my invention.

page_text: 1, 11 are ports in communication with the steam nozzles of the turbines, and
2 is a circular valve provided with steam ports or passages 2ª, 2º, 2º in the form of
slots the lengths and positions of which, relatively to the steam ports 1, 1 1, is
such that when the valve 2 is partly turned through the action of the turbine
governor by which it is controlled, it will cut off or admit steam successively to
the several ports 1, 1, 1 and thus cut off or turn on one or more steam jets,
according to requirement. Thus in the example shown, if the valve be partly
turned to the right, the steam port 1 will be first closed, and if the motion of the
valve be continued sufficiently in the same direction the port 1ª will be closed and
next the port 1, the ports being opened in the reverse order when the valve is
moved in the opposite direction.
For the purpose of obtaining an economical expansion of the steam used in steam
turbines, whether working with or without the regulating apparatus described
above, the steam passing through the main duct is caused to enter and expand into
or within several nozzles the number and cross sectional areas of which are arranged
to suit the increasing volume due to the diminishing pressure, and the increasing
velocity of the steam at each point in its path of efflux.
Fig. 2 is a central longitudinal section of a device suitable for carrying out this
part of my invention.
This device is adapted to be secured at one end 3, as by screwing, to the main
steam duct, of which it practically forms a part. The jet of steam commences at
the contraction at 4 and as the steam increases in velocity the nozzle is developed
into 2 or more separate nozzles as shown at 5, 6 & 7.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed I declare that what I
claim is
1. Regulating the speed of a steam turbine by providing such turbine with
several steam nozzles and controlling the flow of steam to the nozzles by means of
a valve (or valves) that is under the control of a governor and is adapted to cut off
one or more of the steam jets in a successive manner as the load decreases, and to
turn it or them on again as the load increases, substantially as hereinbefore
described with reference to the example illustrated in Fig. 1 of the drawings
annexed.
2. Causing the steam passing through the main steam duct of a steam turbine to
enter and expand into or within several discharge nozzles the number and cross
sectional areas of which are such as to suit the increasing volume and velocity of
the steam at each point in its path of efflux so as to thereby obtain an economical
expansion of the steam, substantially as herein before described with reference to
Fig. 2 of the drawings annexed.
100