Improvements in Steam Turbines.
Year: 1894

page_text: Date of Application, 28th Mar., 1894
Complete Specification Left, 28th Dec., 1894-Accepted, 23rd Mar., 1895
Improvements in Steam Turbines.
I, WILLIAM GLASS WRENCH, of 27 Oswald Street, Glasgow, in the County
of Lanark, Consulting Engineer, do hereby declare the nature of this invention
to be as follows :--
This invention has for its object the improvement of that class of rotary motors
or engines known as steam turbines by the application of thin web jets of steam at
boiler pressure, acting with a momentary kinetic impulse upon the walls of
suitably inclined or curvated vents in the periphery of a rotating wheel and which
by being suddenly clipped off therefrom by the blind ends of the vanes fill the said
vents only partially and for a fractional part of their revolution or circumferential
pitch on the wheel escaping without subsequent check to drop of pressure into the
exhaust space beyond; it being the express object of this design of motor to
avoid squeezing the steam by means of a constantly applied rear pressure through
a series of alternately fixed and moving ports or passages against the successive
resistances interposed by such to its free flow, but rather to embody the principle
of using the steam with a momentarily percussive effect, viz.: by projecting a
detached volume of it against a suitable moving surface as far from the axis as
possible so that leverage high peripheral speed and fewness of revolutions may be
advantageously combined. The objects further aimed at in detail are, (1st) to
have an engine which shall combine efficiency with low speeds, (2nd) to have an
engine able to run at a constant designed speed irrespective of any variation of
the medium load upon it, or of the power put through it to overcome same, or of the
steam pressure (within certain limits) such to be accomplished by mechanism which
shall automatically or otherwise control the number of jets which operate upon the
wheel, (3rd) to have the jets and vents relatively of such an automatic nature that any
slowing down of the wheel is resisted by an intensified and prolonged action of the
jet upon it, before being cut off, thus carrying the point of expansion further
through the vent than it would be with a faster wheel speed, (4th) to have a
neutral chamber, into which air or part of the exhaust steam can be drawn, and
re-passed through the vents by the combination of jet induction and centrifugal
action on the same side of the wheel, with the view of destroying any detrimental
void which might possibly therein exist, (5th) to have an engine applicable to
marine propulsion, capable of reversing by means of right and left handed
wheels, having interchangeable functions, one passive as a fly wheel while the
other is active and vice versa, each open to the boiler or exhaust end alternatively,
as may be desired to propel ahead or astern; the end pressure either way being
balanced by the thrust reaction upon the propeller.
The casing of this turbine is by preference formed as a shallow conoidal pain,
the large end open and flanged to receive the cover which may be simply another
duplicate casing bolted to the first, and containing its own set of turbine mechanisin
with the exhaust or condensing space in the middle, between and common to both
wheels. Enclosed within the casing is an annular steam space formed by means of
an angle ring which keeps the steam directly off the wheel and forms the neutral
chamber before mentioned; this ring having a slotted or perforated face near its
periphery for the projection of the steam jets into the wheel vents opposite, the
primary direction of the jets being approximately at right angles to the plane of the
wheel and inclined radially. Within the steam space so enclosed and bearing

page_text: upon the back of this ring with a steam tight face, is another grid or ported ring,
capable of being moved round slightly so as to open or shut off as many jets as
may be necessary, being actuated by a slotted lever or drag link, connecting
with a lever outside the casing. Between this jet ring and the wide mouth of
the casing is placed the turbine wheel preferably conical on the steam side and
dished on the other and having curved vents cut across its periphery, the walls of
these inclining backwards circumferentially and the intervening vanes (halfcrescent
in section) increasing in diameter as well as in area gradually or by steps towards
their exhaust ends. This turbine may have two active wheels similarly rotative
and unreversible, or one may be active and the other passive alternately for
reversing in which latter case the steam is admitted by one casing end only at a
time the other being open to the exhaust or condenser. Jet or surface con-
densation may be effected in the space between the wheels; the former by a spray
centrifugally produced by the shaft, the latter by interposing the usual cooling
surface and separating the casing halves to suit ; or such condenser may be fitte
as an external attachment.
The jets of steam at first referred to may each consist of a row of smaller jets
instead of being a continuous film in width. It is also intended that there shall be
more vents than jets and that the normal working condition of this turbine shall be
with a number of the jets shut off, or in reserve, the vents thereby running longer
empty or more completely discharging themselves than with all the jets in
operation. The action of each jet playing momentarily into the vent opposite is
simply that of an injector with a strong induction on the steam or inlet side.
gases.
This turbine may be used with elastic fluids other than steam, or with explosive
After the steam has done its work in the wheel vents it may be deflected
in the exhaust space in the direction of the wheel rotation. Oblique passages
may be cut from any vent into that preceding it for the purpose of ventilation if so
desired.
Dated this 27th day of March 1894.
CRUIKSHANK & FAIRWEATHER,
62, St. Vincent Street, Glasgow, Agents.
COMPLETE SPECIFICATION.
Improvements in Steam Turbines.
I, WILLIAM GLASS WRENCH, of 27 Oswald Street, Glasgow, in the County of
Lanark, Consulting 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 its object the improvement of that class of rotary motors
or engines known as steam turbines, by the application of thin web jets of steam at
boiler pressure, acting with a momentary kinetic impulse upon the walls of suitably
inclined or curvated vents in the periphery of a rotating wheel, and which, by being
suddenly clipped off therefrom, by the blind ends of the vanes, fill the said vents
only partially and for a fractional part of their revolution or circumferential pite 1
on the wheel, escaping without subsequent check to drop of pressure into the
exhaust space beyond; it being the express object of this design of motor, to avoit
squeezing the steam by means of a constantly applied rear pressure, through a
series of alternately fixed and moving ports or passages against the successive
resistances interposed by such to its free flow, but rather to embody the principle
of using the steam with a momentarily percussive effect: viz.: by projecting
detached volume of it against a suitable moving surface as far from the axis as
possible, so that leverage, high peripheral speed and fewness of revolutions, may be
advantageously combined. The objects further aimed at in detail are, (1st) to
a

page_text: have an engine which shall combine efficiency with low speeds, (2nd) to have an
engine able to run at a constant designed speed irrespective of any variation of the
medium load upon it, or of the power put through it to overcome same, or of the
steam pressure (within certain limits) such to be accomplished by mechanism
which shall automatically or otherwise control the number of jets which operate
upon the wheel, (3rd) to have the jets and vents relatively of such an automatic
nature, that any slowing down of the wheel is resisted by an intensified and
prolonged action of the jet upon it, before being cut off, thus carrying the point of
expansion further through the vent than it would be with a faster wheel speed,
(4th) to have a neutral chamber, into which air or part of the exhaust steam can
be drawn, and re-passed through the vents by the combination of jet induction and
centrifugal action on the same side of the wheel, with the view of destroying any
detrimental void which might possibly therein exist, (5th) to have an engine
applicable to marine propulsion, capable of reversing by means of right and left
handed wheels, having interchangeable functions, one passive as a fly wheel while the
other is active, and vice versa, each open to the boiler or exhaust end alternatively,
as may be desired to propel ahead or astern; the end pressure either way being
balanced by the thrust reaction upon the propeller.
In the accompanying drawings which illustrate my invention
Figure 1 is in part an elevation and in part a longitudinal vertical section of a
modification of my improved steam turbine fitted with two rotating wheels,
Figure 2 is a transverse vertical section of the same taken as at several lines in
order to show the construction of the several parts.
Figure 3 is a sectional developed plan view showing the wheel vents, jet orifices
and cut off plate.
Figure 4 is a similar view showing a modified form of the jets.
Figure 5 is an elevation of the engine in which the casing is formed with brackets
for carrying the journal bearings of the shaft.
The casing of this turbine by preference formed as a shallow conoidal pan A,
the large end open and flanged at a to receive the cover A¹ which may be simply
another duplicate casing bolted to the first, and containing its own set of turbine
mechanism, with the exhaust or condensing space B in the middle, between and
common to both wheels C, C. Enclosed within the casing A, A¹, is an annular
steam space D, formed by means of an angle ring E, which keeps the steam directly
off the wheel C and forms at F the neutral chamber before mentioned, this ring E
baving a slotted or perforated face or being formed with jet orifices e near its
periphery for the projection of the steam jets into the wheel vents c opposite, the
primary direction of the jets being approximately at right angles to the plane of
the wheel and inclined radially. Instead of forming all the vents in the wheel, each
alternate vane may as shown at a Figure 2 be dovetailed or otherwise fitted
between vanes formed on the wheel in order that the vents may be accurately
shaped. Within the steam space D so enclosed and bearing upon the back of this
ring E with a steam tight face, is another grid or ported ring G capable of being
moved round slightly so as to open or shut off as many of the jet orifices e or jets
as may be necessary, being actuated by a slotted lever or drag link h connected by
a shaft with a lever H outside the casing or by means of a centrifugal or other
governor connected to the lever H. Between the jet ring E and the wide mouth
of the casing is placed the turbine wheel C preferably conical on the steam side
and dished on the other and having the curved vents e cut across its periphery, the
walls of these curving or inclining straight backwards circumferentially with an
increasing inclination towards the exhaust end and the intervening vanes (half-
crescent in shape) increasing in diameter as well as in area, gradually or by steps
towards their exhaust ends. This turbine may have two active wheels C, C,
similarly rotative and unreversible, or the one may be active and the other passive
alternately, for reversing, in which latter case the steam is admitted by one casing
end only at a time, the other being open to the exhaust or condenser. Jet or surface
condensation may be effected in the space B between the wheels; the former by a

page_text: spray centrifugally produced by the shaft, the latter by interposing the usual cooling
surface and separating the casing halves to suit; or such condenser may be fitted as
an external attachment.
The jets of steam at first referred to may each consist of a row of smaller jets
instead of being a continuous film in width, it is also intended that there shall be
more vents than jets or that they shall be otherwise odd in number and that the
normal working condition of this turbine shall be with a number of the jets shut
off, or in reserve as indicated by Figures 3 and 4, the vents thereby running longer
empty or more completely discharging themselves than with all the jets in
operation. The action of each jet playing momentarily into the vent opposite is
simply that of an injector, with a strong induction on the steam or inlet side.
This turbine may be used with elastic fluids other than steam, or with explosive
gases. After the steam has done its work in the wheel vents it may be deflected
in the exhaust space in the direction of the wheel rotation, by inserting a ring
within the exhaust space opposite each wheel face fitted with deflecting blades as
shown by dotted lines at Figures 1 and 3 or each blade may be fitted separately to
the casing shell. Oblique passages may be cut from any vent into that preceding
it for the purpose of ventilation if so desired.
The drawings illustrate a small size of engine. In larger sizes the casing may
consist of more sections so modified as to permit of more ready access to the internal
parts, and the gear here shown to turn the grid and regulate the number of active
steam jets may be otherwise constructed such as with a drag link or worm operated
by a rod passing more or less tangentially through the casing and which gear is to
be automatically regulated by the shaft speed, if so required. In some cases the
cut off grid G may be dispensed with as for example in small engines intended to
drive a practically constant load under unvarying conditions.
As no protruding part of the shaft is subject to a positive steam pressure, no deep
steam-tight stuffing boxes are required, but only a mere turn of packing slightly
compressed between two plates as shown at I so as to prevent communication
between the atmosphere or condenser and the neutral space F.
It is to be understood that in a double wheeled reversing engine of this type the
whole of the pro tem. passive end including the spaces D, F, and all other ports or
passages may have open communication in common with the space B to either the
atmosphere or condenser in which latter case the passive wheel will rotate in a
vacuum. This applies to either end.
In some cases the wheel vanes instead of being exactly half-crescent in shape
may have a slight backward or return curvature without in any way reducing the
area of their blind ends for cutting off purposes. In such cases the jets would be
inclined more in the direction of the wheel rotation.
The wheels C may be solid or built or fitted as shown with a peripheral ring or
rings of stronger material. If made laminated as indicated at the right hand side
of Figure 3, the object would be to facilitate the due shaping of the vents. They
may also have a peripheral shrouding as indicated at 6 Figure 1 with the steam end
lipped and slightly overlapping the jet.
The steam inlet and jet regulating gear may be placed in any suitable position
on the casing rim or end.
The shaft bearings may be supported on projectious cast on or attached to casing
as indicated at Figure 5 instead of upon brackets attached to sole plate as shown
at Figures 1 and 2 and upon which the turbine itself may be suspended.
The turbine may be single wheeled or double wheeled single acting, i.e. each
wheel similarly rotative and exerting similar power or it may be double wheeled
reversible the power of the latter being that put through one wheel at a time plus
any addition due to vacuum which may affect the other wheel.
My improved turbine differs from such apparatus as heretofore constructed in
the following essential features, viz.: (1) The admission of steam through the
casing to the wheel and all its vents is intercepted by the interposition of a division
plate (here designated a jet ring) through which the steam must first pass in thin

page_text: film or web jets to reach the wheel. (2) Such jets impinge upon the leading walls
of any vents during the passage only of such vent mouths across any open jet
orifices. (3) The blind ends of the vanes and the blind surface of the jet ring
between the jet orifices are arranged and proportioned to act as a cut off, and clip
the jets off from the rent at a sinall fractional part of its pitch on the circumference
of the wheel. (4) Such combination permits of the full expansion of the steam (in
the moving vents to lowest possible pressure) being carried out in any isolated or
shut off vent and which vent therefore practically empties itself before the rotation
of the wheel brings it opposite to the next jet which is always in advance of the
empty vent in the direction of the wheels rotation. (5) The detached steam jets
are delivered into practically empty vents. (6) The jet ring or division plate
separates the casing into two important chambers viz. a live steam space and a
neutral space on the same side of the wheel. (7) The number of active jets passing
through the jet ring to the wheel can be regulated by a grid or ported ring at its back
in the steam space. (8) Each active jet playing momentarily into an opposite vent
acts distinctly as an injector and creates an induction in the direction of its discharge.
This property can be utilized to draw part of the exhausted steam from the exhaust
space into the neutral space to be re-passed through the wheel. (9) The centrifugal
action of the wheel assists the inductive action of the jet in creating a negative
pressure in the neutral space and re-passing the exhaust steam through the wheel.
(10) In a reversible and condensing engine the passive wheel and the whole of the
exhaust side of the active wheel may rotate in a vacuum, and in a non-reversible
condensing engine the whole of the exhaust side of the wheel or wheels may rotate
in a vacuum. (11) Should any varying load tend to affect the revolution the speed
is to be uniformly maintained by a governor acting automatically upon the grid
ring, increasing or diminishing the number of active jets to suit.
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. A steam turbine the parts of which are constructed combined and arranged to
operate substantially as herein described with reference to the accompanying
drawings.
2. A steam turbine composed of a casing enclosing a rotating wheel or wheels
operated by the impact and expansion of detached steam jets upon curvated vents
in the wheel, the jets being directed through a jet ring adapted to supply steam to
the whole of the vents in rotation but simultaneously to only a proportion of them,
substantially as described.
3. A steam turbine composed of a casing enclosing two rotating wheels each
having vents upon which steam jets are directed through jet orifices the wheels
being adapted to be operated one at a time and in opposite directions one wheel
being passive while the other is active, substantially as described.
4. In a steam turbine the combination with a rotating wheel having vent orifices
and a ring having jet orifices therein for directing steam jets into the wheel vents
of a movable grid operated either by hand or automatically and adapted to close or
open a greater or less number of the jet orifices for regulating the power or speed
of the wheel substantially as described.
5. In a steam turbine the combination of the rotating wheel and a stationary jet
ring supplying steam thereto the parts being so constructed as to form a neutral
chamber between the wheel and jet ring substantially as set forth.
Dated this 26th day of December 1894.
WALLACE FAIRWEATHER,
Chartered Patent Agent,
62, St. Vincent Street, Glasgow, Agent for the Applicant.