Improvement in Elastic Fluid Turbines.
Year: 1897

page_text: Date of Application, 7th Sept., 1897-Accepted, 9th Oct., 1897
COMPLETE SPECIFICATION.
Improvement in Elastic Fluid Turbines.
I, CLAUDE KENNEDY MILLS, of 23 Southampton Buildings, in the County of
London, Patent Agent, do hereby declare the nature of this invention (a com-
munication to me from Charles Gordon Curtis, Engineer, of 441, Park Avenue,
New York City, in the County and State of New York, United States of America)
and in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement:-
-
The invention relates to elastic fluid turbines such as described in Patents
Nos. 19246, 19247, and 19248, dated September 1st, 1896.
Its object is.
(1) To so construct the turbine that it may readily and by simple adjustment
be operated either as a condensing or non-condensing engine, and may be readily
adaptable to operate efficiently with different boiler pressures: and
(2) To provide a more simple and effective form of expansion nozzle adjustable
to vary the volume of the fluid jet without substantial variations in its velocity,
for the purpose of controlling the speed or power of the engine.
In the drawings, Fig. 1. is a sectional plan view through the nozzle and
working passage of the turbine, illustrating the present improvements
Fig. 2. is a vertical section on the line 2. 2. in Fig. 1.
Fig. 3. is a cross-section of the nozzle illustrating a modification in its form.
Fig. 4. is an elevation from the inside of a portion of one of the heads of the
shell of the turbine showing the attachment of the nozzle thereto.
Fig. 5 is a vertical section through the circumferential portion of the shell of
the turbine and through the block which carries the vanes forming the inter-
mediate or stationary passages, the discharging ends of such vanes being shown
in elevation.
The rotating portion of the turbine is a wheel carrying upon its periphery
two complete annular ranges of curved vanes A, B, through which the elastic
fluid passes in succession. This wheel is mounted on a shaft in a suitable shell
or case having circular heads C, D), and a circumferential or annular portion E,
connecting the heads C, D, at their peripheries. F, is a casting, in one or more
parts, having a curved form, and let into a curved slot in the head C, of the shell
as shown in Fig. 4. and secured to the head C by rivets or bolts a.
This casting
carries the expansion nozzle G, having a contracted inner end or throat b, and a
larger outer or discharging end c. Back of the throat 6 of the nozzle the casting F
is provided with the port H, which is connected with a steam boiler or other source
of supply of elastic fluid under pressure, and back of the port H the casing F
is extended into a chamber I. The discharging end d of the outer side wall of
the nozzle is made parallel or approximately so with the inner side wall e of
the nozzle, but from the point f on the outer side wall the angle of the wali is
changed to the inner end of the wall at the throat 6 producing a side 9 which
diverges with reference to the inner side wall e away from the throat b, thus
giving the elastic fluid passing through the throat 6 the proper degree of expan-
sion after which the elastic fluid jet is guided to the delivery end of the nozzle
by the parallel side walls d, e, so as to give the steam particles a parallel motion

page_text: and deliver them at the same angle to the vanes A throughout the section of the
jet.
To permit an adjustment of the nozzle for varying the volume of the elastic
fluid jet without substantial variations in its velocity and thus govern the speed
or power of the turbine, I provide a sliding tongue K which carries the inner
side wall of the nozzle. This tongue K slides in a groove in the nozzle
casting F, its inner end h terminating in a wedge point which enters the opening
through the casting F forming the discharging end of the nozzle. The form
of the discharging end of the nozzle which is particularly shown in Fig. 4. is
an oblong curved opening corresponding with the circle described by the movable
vanes and having parallel top and bottom edges i, k, and radial side edges 1, m.
so as to deliver the elastic fluid jet in a form corresponding precisely to the form
of the opening presented by the receiving ends of the movable vanes. The
tongue K is inclined rearwardly away from the throat 6 of the nozzle and extends
into the chamber I where it is guided at both sides of the chamber. Its out-
wardly turned inner end is connected by a link n with a plunger L passing out
through a stuffing box. A hole o shown in dotted lines, admits the elastic fluid
pressure to the inner end of the plunger L. Since there is a gradually declining
pressure on the inclined face e of the tongue K, the average of this pressure will
be less than that which is exerted on the inclined face of the
tongue to the rear of the throat b where the tongue receives the
full pressure from the port H. The size of the plunger L is such as
to counterbalance this difference in pressure. By sliding the tongue K forward,
its widest point (at the letter b in Fig. 1.) will describe a straight line approach-
ing the point where the angle of the outer side wall of the nozzle changes, and
at the same time the extreme forward end h of the sliding tongue K will approach
the inner end of the outer side wall d, and in this way the cross-sectional areas of
the nozzle will be varied throughout its length, the rate of such variation being
proportional to the several cross-sectional areas, so that the volume of the elastic
fluid jet will be changed without changing the ratio of expansion, upon which
the velocity of the fluid jet depends.
It will be seen that since the widest point of the tongue K will close the space
between it and the diverging slide 9 in passing from the innermost point of
adjustment shown in Fig. 1. to the point f, and that the end h of the tongue will,
at the end of the same movement, touch the inner end of the surface d, there
will be a proportional variation in the size of the nozzle throughout the length
of the surface e for every movement of the tongue K, however great or small the
movement may be, and this whatever may be the adjustment, to be presently
described, of the diverging outer side wall g. The tongue K may be moved by
hand through a suitable connection with the plunger L or it may be moved
automatically through a connection with a speed governor or other device respon-
sive to variations in speed or power. The top and bottom walls of the nozzle
may be parallel as shown in Fig. 2 or they may diverge inwardly as shown in
Fig. 3.
To adapt the turbine to work either as a condensing or non-condensing engine,
means are provided for varying the ratio of expansion in the nozzle and through-
out the working passage of the turbine, so that such a variation can be made
as will adapt the turbine to work with high efficiency at different terminal
pressures of the elastic fluid. For this adjustment of the nozzle I make the
outer side wall d. f. g. of the nozzle in the form of a plate p, of steel or other
elastic metal, which is secured against the outer side wall along the surface d,
and is free from the point f to its inner end. At the point f the plate p is cut
away on its inner side so as to make it thinner and give elasticity at that point.
The inner end of the plate p terminates in a block q sliding on a surface ŕ and
connected with a screw rods extending through a stuffing box in the casting F,
and engaging with a nut operated by a handle M. By turning the handle M
the block can be moved and any desired adjustment given to the diverging

page_text: side wall g. By the adjustment of the wall g the throat 6 of the nozzle can be
made larger or smaller and the angle of divergence or expansion from the throat b
to the point f can thus be changed so as to vary the ratio of expansion of the
elastic fluid in the nozzle, and thus give the proper degree of expansion when the
turbine is working either as a condensing or non-condensing engine or to accommo
date the turbine to a variation in the boiler or initial pressure of the elastic fluid.
Since a different ratio of expansion throughout the working passage of the
turbine beyond the delivery end of the nozzle will be required for efficient
operation under the different exhaust pressures used in condensing and non-
condensing work, the turbine is provided with means for accomplishing this.
This is done by providing two intermediate stationary passages between the two
sets of movable vanes, such intermediate passages being movable so that one or
the other can be brought into line with the fluid jet, and the greater expansion
required for the condensing engine is given by expanding one of the intermediate
passages at its discharging end circumferentially so as to include more of the
vanes of the second set of vanes than will be included by the discharging end
of the other intermediate passage. The two intermediate passages are composed
of a number of curved vanes N, O, to divide the fluid jet and automatically adjust
the size of the passage to the size of the jet. The vanes N, O, are carried by a
curved block P which is let through a rectangular opening in the shell E of
the turbine. The block P is provided with overlapping ends which cover at
all times the opening t, and by moving this block in the opening t either the
vanes N or the vanes O can be brought into line with the nozzle and with the
discharge opening Q which opens out of the head D of the shell, and which may
be connected with a condensing or atmospheric exhaust, or with another turbine.
Bolts or other suitable means are provided for securing the block P in each
position of adjustment.
It will be understood that the working passage through the movable vanes A, B,
and the stationary vanes N, or O, is expanded radially in the direction of the
flow of the elastic fluid to overcome frictional retardation, as described in the
patents already referred to. This expansion is assumed to be sufficient in
the turbine illustrated in the drawings to effectively conduct the fluid jet through the
intermediate stationary passage when the turbine is working as a non-condensing
engine, and hence the vanes N are illustrated as having the same area circum-
ferentially at their discharging ends as at their receiving ends. To provide the
still further expansion in the intermediate stationary passage which is required
when the turbine is working as a condensing engine, the vanes 0 are spread out
at their discharging ends so as to deliver the fluid jet to a number of the vanes B
greater than the number of the vanes A from which they receive the fluid. In
order to accomplish this and still give the same angle of discharge to the tails
of all the vanes O, these vanes are made progressively longer in their curved
portions and shorter in their straight discharging portions, as illustrated in Fig. 1.
As illustrated in Fig. 1. the stationary vanes N are in line with the nozzle G
and the discharge port Q and the adjustment of the diverging wall is assumed
to be such as will be required when the turbine is running as a non-condensing
engine. To adjust the turbine for condensing work, the block P carrying the
stationary intermediate vanes will be moved so as to bring the vanes 0 in line
with the nozzle G and the discharge port Q, and the diverging wall g will be
adjusted into the position indicated in the dotted lines to give the required
additional expansion to the elastic fluid.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed I declare that what
I claim is:
1. In an elastic fluid turbine, an obliquely arranged expansion nozzle having a
contracted throat, a diverging portion beyond the throat, and parallel delivery
walls at the sides of the nozzle, the parallel delivery walls being produced by

page_text: changing the angle of the longer outer side wall at its delivery end so as to make
it substantially parallel with the inner or shorter side wall of the nozzle, sub-
stantially as set forth.
2. In an elastic fluid turbine, a delivery nozzle having an oblong curved dis-
charging end with parallel top and bottom edges substantially as set forth.
3. In an elastic fluid turbine, an expansion nozzle having parallel side walls
at the discharging end of the nozzle, in combination with means for varying the
cross-sectional area of the nozzle throughout its length simultaneously and
proportionately, substantially as set forth.
4. In an elastic fluid turbine, an obliquely arranged expansion nozzle having
the angle of its longer outer side wall changed at the delivery end of the nozzle
so as to be parallel with the shorter or inner side wall of the nozzle, in com-
bination with a sliding piece which forms the inner or shorter side wall of the
nozzle, substantially as set forth.
5. In an elastic fluid turbine, a curved delivery nozzle, in combination with a
curved slide for adjusting said nozzle simultaneously and proportionately at its
receiving and discharging ends, substantially as set forth.
6. In an elastic fluid turbine, an obliquely arranged expansion nozzle having a
straight inner or shorter side wall and having the angle of its longer or outer
side wall changed intermediate between its ends so that its delivery end is made
substantially parallel with the inner side wall, in combination with a sliding
piece which forms the inner side wall and which by its adjustment is caused
to approach towards or recede from the parallel portion of the outer side wall
and thereby vary the cross-sectional area of the nozzle simultaneously and pro-
portionately from its receiving to its discharging end, substantially as set forth.
7. In an elastic fluid turbine, the combination with a jet expansion delivery
nozzle, of means for varying the cross-sectional area of the nozzle, and a plunger
or piston for balancing any excess of pressure on the movable parts, substantially
as set forth.
8. In an elastic fluid turbine, the combination of a delivery nozzle and a
working passage through movable vanes, adjustable to vary the ratio of expansion
so as to adapt the turbine either for condensing or non-condensing work or for
different boiler or initial pressures, substantially as set forth.
9. In an elastic fluid turbine, an expansion delivery nozzle adjustable to vary
the ratio of expansion, substantially as set forth.
10. In an elastic fluid turbine, an expansion delivery nozzle having one or more
of its diverging walls adjustable to vary the ratio of expansion, substantially
as set forth.
11. In an elastic fluid turbine, the combination with two sets of movable vanes,
of two stationary intermediate passages movable alternately into operative
position, such passages having different ratios of expansion throughout their
length, substantially as set forth.
12. In an elastic fluid turbine, the combination with two sets of movable vanes,
of a stationary intermediate passage expanded circumferentially at its discharging
end so as to embrace more vanes at its discharging end than at its receiving end,
substantially as set forth.
13. In an elastic fluid turbine, a delivery nozzle adjustable to vary the ratio
or degree of conversion of pressure into velocity, and also adjustable to vary
the volume of the fluid without substantial variation in its velocity, substantially
as set forth.
14. In an elastic fluid turbine, a delivery nozzle having one of its sides adjust-
able to vary the volume of the fluid without substantial variations in its velocity,
and its opposite side adjustable to vary the ratio of conversion of pressure into
velocity, substantially as set forth.
15. In an elastic fluid turbine, an expansion nozzle having in combination the
adjustable diverging side g and the adjustable tongue K, substantially as set

page_text: 16. An elastic fluid turbine having in combination the nozzle G provided with
adjustable parts K g, two sets of movable vanes A B, and the two sets of stationary
vanes NO movable alternately into position for operation, substantially as set
forth.
Dated September 7th 1807
HARRIS & MILLS,
23, Southampton Buildings, Chancery Lane, London, W.C., Agents.