Year: 1899

page_text: Date of Application (in United Kingdom), 3rd Oct., 1899
Complete Specification Left, 3rd July, 1900-Accepted, 3rd Dec., 1900,
I, ERNESTO FERRETTI, of 72, Via Montebello, Rome, in the Kingdom of Italy,
Chief Engineer of the Royal Italian Navy, now of H.M. Ship Carlo Alberto, do
hereby declare the nature of this invention to be as follows:
This invention relates to turbomotors and the objects of the said invention
are as follows:
1st to remove all sources of vibration by means of the completely symmetrical
arrangement of the parts; 2nd to allow of a complete expansion of the steam
to take place; 3rd to prevent any leakage of steam between the stationary and
the rotating parts of the apparatus. For the reasons hereinafter set forth the
power of a motor of a given size constructed according to my invention is con-
siderably larger, if the motor is intended to run in one direction only than is
the case, when the motor is to run in both directions.
My improved turbomotor consists of three essential parts, namely,
tributing apparatus and two expansion cones.
a dis-
The steam or other fluid enters the distributor and escapes through suitable
ports, flows through the turbines upon which it exerts its impulse on the various
couples of wheels, which wheels are alternately fixed wheels or guide-wheels and
rotating wheels or runners.
The distributing apparatus consists of an annular casing receiving fresh steam
from the boiler and injecting the same at a convenient angle both towards the
right and left through inclined nozzles. Each of the said nozzles is fitted with
a valve controlled by means of a hand wheel whose spindle passes through a
stuffing box.
The sets of nozzles i.e. a right hand set and a left hand set of nozzles are
arranged to work either separately or conjointly according to the direction in
which the motor revolves either for reversing or otherwise.
I will first assume that the motor is running in one direction only.
The steam collected within the distributing apparatus escapes through both
the sets of the hereinbefore mentioned nozzles, whose openings are entirely or only
partly open according as the motor is running under full load or not.
The steam entering the expansion cones first impinges on the running wheels
of the turbines keyed on the shaft symmetrically arranged on both sides of the
distributing apparatus.
On leaving the turbines the steam flows on both sides through the other tur-
017

page_text: bines each of which consists of a guide-wheel and a rotating wheel, all of the
guide wheels being connected to the casing and all of the rotating wheels being
keyed on the shaft.
The area of the outflow orifices of each turbine is to be calculated so as to
cause the steam to escape with about half the pressure, with which it enters
the turbine.
The directions of the passages of the guide and rotating wheels of each couple,
.e. of the same turbine meet each other at an angle of about 90°.
The guide-wheels must have about double the depth of the rotating wheels.
The vanes of the latter must be shaped so as to present wide open passages
towards the inflow of steam.
The play between a guide and a rotating wheel, pertaining to the same turbine,
must be as small as possible, while a much greater interval acting as a receiver
may exist between two adjacent couples of wheels, i.e. between two turbines.
The number of vanes or buckets in both kinds of wheels, as well as their radial
height, must increase from the distributing apparatus towards the outflow pipes:
the area of the inflow guide passages corresponding only to a small fraction
(say or less) of the area of the outflow bucket passages.
The steam will therefore leave the apparatus with a much reduced speed and at
a pressure slightly in excess of the atmosphere or condenser pressure, if a con-
denser is connected therewith. The form of the expansion cones is intended not
only to secure a large degree of expansion, but also through the arrangement of
the casing, which internally expands by steps, the steam is prevented from
escaping directly from the nozzles to the outlet pipes through the clearance spaces
around the turbines, in as much as the steam leaking from the 1st turbine, without
having done work, is caught by the 2nd turbine and so on.
The shaft longitudinally extending from one end to the other of the apparatus
passes through the covers of the expansion cones, which covers are made tight
by rings which the steam presses against raised parts of the covers. The bearings
are carried by a bracket cast in one piece with said covers while the whole
apparatus rests upon a base made in two pieces and a common foundation plate.
Each of the casings as well as each of the guide-wheels are also made in two
pieces.
Should the movement of my improved turbomotor require to be reversed, the
following alterations should be introduced.
1) The herein before mentioned nozzles ought to operate separately from each
other, the first set of nozzles working when the motor runs in one direction and
the second set when it is running in the opposite direction.
2). The vanes or buckets on the right side of the distributing apparatus should
he inclined in the same direction as those on the left side, while they must be
symmetrical i.e. inclined in opposite directions, when both sets of nozzles act at
one time as it is the case in a non-reversible motor.
3). Moreover the shaft should be fitted with steam tight packings at the points
where it passes through the distributing apparatus.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.
Improvements in Steam Turbines.
I, ERNESTO FERRETTI, of 72, Via Montebello, Rome, in the Kingdom of Italy,
Chief Engineer of the Royal Italian Navy, now of H.M. Ship Carlo Alberto, do
hereby declare the nature of this invention and in what manner the same is to

page_text: be performed, to be particularly described and ascertained in and by the following
statement:
This invention relates to steam turbines and has for its objects to provide
improved means whereby all sources of vibration are removed owing to the com-
plete symmetrical arrangements of the parts; and the leakage of inoperative steam
between the stationary and the rotary parts of the apparatus may be effectually
prevented.
The power of a motor or turbine of a given size constructed in accordance with
this invention, is considerably larger, if the motor is intended to run in one
direction only, that is the case when the motor is adapted to run in both directions,
as will be explained more particularly hereinafter.
In order that my invention may be readily understood and carried into effect I
will describe the same fully with reference to the accompanying drawings in
which:
Figure 1 is an elevation, partly in section of an improved steam turbine
embodying my invention.
Figure 2 is an end elevation of the distributing apparatus drawn to a larger
scale.
Figure 3 is a section on line of Figure 2.
Figure 4 is a section on line y-y of Figure 2.
Figures 5 and 6 are details of the rotary wheels, Figure 5 being a section on
line 5-5 of Figure 6.
My improved turbine consists of three essential parts, riz.-a distributing
apparatus A, and two expansion cones or casings C C Figure 1.
The steam or other motive fluid enters the distributor through the inlet port a
and through suitable passages 6 61, Figure 2, into the turbine wheels c where-
upon it acts by impulse on the various couples of wheels d e f g h (Figure 1)
such wheels forming alternately, fixed or guide wheels or steam discharge cham-
bers, and rotary wheels or runners; the steam then finally escaping through the
exhaust ports or openings kk Figure 1
The distributing apparatus consists of a casing A formed with an annular
chamber B, into which the steam or other motive fluid is admitted through the
port a. The steam is injected in the turbine wheels at a convenient angle (see
Figures 3 and 4) towards both the right and left through inclined passages bbl
leading from the chamber B. Each of said passages is closed by a valve B
operated by means of a hand wheel attached to the valve spindle passing
through a stuffing box p The several sets of passages (i.e. a right hand and a
left hand passage to each set) are arranged in such a manner as to be capable of
being operated either singly or together according to whether it is desired to run
the motor in one direction only or from a reversible motor.
In a non reversible motor the steam collects within the annular chamber B of
the distributing apparatus A, flows simultaneously through both sets of passages
(after their respective valves have been sufficiently opened to suit the load on the
motor) and then enters both the expansion-cones C, C¹, and first impinges on the
running wheels keyed on the shaft X Y. These running wheels are arranged
on both sides of the distributing apparatus and the vanes of the wheels are sym-
metrically formed in opposite directions but in such a manner as to drive the
shaft XY in one direction. On issuing from the turbine wheels & the steam flows
in both the casings C, C through the turbine-wheels d e f g h each of which
co-operates with a fixed portion or discharge chamber as herein before described.
In Figure 1 the fixed portions or discharge chambers are shewn in elevation,
while the rotary wheels are shewn in section.
The discharge chamber for each turbine wheel is of such a capacity in propor-
tion to its corresponding wheel as to cause the steam to expand to about one half
the pressure with which it enters any of the turbine wheels.
Said discharge chambers are preferably about double the depth of the rotating
wheels, and the vanes of the latter (see Figures 5 and 6) are so constructed as to

page_text: present wide admission passages for the inflow of steam and with narrow outlets
towards the discharge chambers as indicated in Figure 6. The vanes may be
curved and tapered towards the outer edge at the admission side of the wheels
so as to form large operative surfaces for the impinging steam jets which latter
then force their way through the narrow inclined passages leading to the rear
of the wheels, with an increased velocity and thereby produce a more effective
action than with vanes forming ordinary parallel passages.
The space between the rear face of a rotating wheel and its discharge chamber
forming the same couple must be as small as possible, but a much greater space
may exist between two adjacent couples of wheels.
The number of vanes in both the wheels and the discharge chambers as well
as their diameters increase from the distributor A, towards the exhaust ports k k¹,
the combined areas of the steam inlet passages at 6 are equal to a small fraction
only (say one quarter, or less) of the area of the outflow passages at h. The
steam will therefore leave the apparatus with a much reduced speed and at a
pressure slightly in excess of the atmosphere or condenser pressure (if a condenser
is connected therewith).
The form of the casing or expansion cones CC is intended not only to secure a
large degree of expansion but also through the arrangement of the casing, which
internally expands by steps, the steam is prevented from escaping directly from
the passages
66 to the exhaust pipes k k owing to the arrangement of clearance
spaces around the turbine wheels whereby any steam leaking from the first turbine
wheel without having done work, is caught by and expands in the second turbine
wheel and so on.
The longitudinal shaft X Y extends from end to end of the turbine and passes
through the covers D D¹ of the exapnsion cones or casings CC₁ said covers being
rendered steam tight by means of rings which the steam presses against the
raised parts or bosses m of the covers D D'.
The bearings E E¹ are carried by brackets cast in one piece with or otherwise
fixed to the covers 1) D' and the whole turbine is supported by means of a base F
made in two parts and fixed on a common foundation plate G.
Each of the casings C C as well as each of the guide wheels are formed of
two parts suitably secured together.
In order to enable my improved turbine to be used as a reversible engine the
passages in the distributing apparatus are so arranged as to operate indepen-
dently, the first set working when the motor runs in one direction and the other
set when it is running in the opposite direction, and the vanes of the rotary
wheels are so arranged as to cause each set of these latter to run in opposite
directions.
It should be understood that in this reversible turbine only one set of rotary
wheels is operative at a time the other, inoperative, set merely runs free; it will
thus be obvious that in this case the motor will only run with half the power of
the non reversible turbine. The shaft X Y is provided with suitable steam-tight
packings at the points where it passes through the distributing apparatus.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is: -
1. In a steam or other motive fluid turbine, a single or double truncated
conical shaped casing, a central longitudinal shaft arranged therein and adapted
to carry a series of graduated turbine wheels located in said casing substantially
as herein before described and illustrated by the accompanying drawings.
2. In a steam or other motive fluid turbine a single or double conical casing, a
longitudinal shaft arranged therein a series of graduated turbine wheels mounted
on such shaft in such a manner that expansion occurs step by step thereby pre-
venting inoperative steam from escaping directly through the clearing spaces
substantially as described and illustrated by the accompanying drawings.

page_text: 3. A steam or other motive fluid turbine constructed substantially as above
described and provided with a distributing apparatus having inclined passages by
means of which the direction of motion of the turbine may be regulated sub-
stantially as described and illustrated by the accompanying drawings.
4. A steam or other fluid turbine constructed arranged and operating substan-
tially as above described with reference to the accompanying drawings and for
the purpose specified.
The 9] day of T. 1000
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.