Note: Descriptions are shown in the official language in which they were submitted.
1()~i1'71~
PRESSURE GAS ENGINE
Back~ro!~nd of the Tnvent.;on
This invention relates to a prcssure gas eny;ne in
which high velocity gas is blas~ed from an arcua~e series of
nozzles to~ard the rim of a rotor that is closely adjacent to
the nozzle exits. This rim at its periphery is provided with
arcuate buc~ets into which these blasts of gas are received. Both --
the entrances and the exits of the buckets are located at this
per.iphery. The gas after flowing over~ the arcuate surfaces of the
buckets,which are each arranged on a chord of the rim that is
closely adjacent to a tangent to the rim that is parallel to the
chord, passes from the bucket exits at very low back pressure so
that there is a high efficiency conversion of gas velocity to
rotary power.
The pressure gas engine or turbine of this invention
contrasts in efficiency of power conversion to the customary re-
entry type of turbine. These re-entry turbines are the type
disclosed in many prior U.S. patents including the following: 748,678;
751,589; 845,059; 910,428; 911,492; 979,077; 985,885; 992,433; `
1,145,144; 1,546,744 and 3,197,177.
It has been discovered that by providing a straight
through passage of the gas from the nozzles through the buckets
and into a volumetric section of low fluid back pressure a major ~
improvement in performance is achieved. ~his is true for many ; -
reasons. For example, in the re-entry impulse type of turbine
where the gas flows successively through a series of re-entry
stages the relative velocity of the fluid passing from one re-
entry stage to the next constantly decreases while the density of
the gas remains constant. Consequently, as the velocity of the
gas flowing through the re-entry passages and buckets decreases
the cross sectional area of the gas flow increases in inverse
proportion.
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Attempts have been made in the past to solve this problem
of increasing cross sectional area of the gas stream with decreas-
ing speed from one re-entry stage to the next by prov;ding an escape
path for some of the gas stream before all of its kinetic energy
is converted to power on the re-entry. ~owever, this has not been
satisfactory so that such re-~try stage turbines have never been
very efficient. Further, the high velocity gas which actually
makes a full trip through the successive re-entry stages is sub-
ject to a multitude of effects resulting from the long and
tortuous path that the gas must take in the re-entry stages and
the resulting improper re~tive angle3 of entry of the recircula-
ting gas to the rotor which is traveling at constant speed. This
type of path tends to convert the kinetic energy of the gas stream
to heat rather than to work on rotating the rotor.
In contrast, the turbine of this invention does not sub-
ject the high velocity gas to a long path to convert its energy ~ -
to shaft horsepower in the rotor but goes contrary to these prior
teachings in providing the shortest possible path from the nozzles
through the buckets to the exhaust area. Many tests have shown
that this elimination of the re-entry stages of the prior art
coupled with a corresponding increase in turbine rotor rim speed
greatly improves the efficiency of the engine. This efficiency
is defined as the conver-sion of the pote`ntial energy of the com-
pressed gas to shaft horsepower and with the engine of this in-
vention is much greater than has been achieved before to the best
of my knowledge.
Summary of the Invention
_
In this invention the engine comprises a rotor in a
c~ing with the rotor having a circular rim rotatable about an axis
Of rotation. At the rim periphery the:e is provided a single
series of closely adjacent impulse buckets with each bucket lying
on a chord of the rim that is adjacent to a tangent that is
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parallel to this chord. Each bucket has an arcuate impulse
surface of substantially constant radius transverse to the
direction of rotation of the rotor and extending from an entrance
side of the bucket at the rim periphery to an opposite exhaust
side of the bucket that is at the rim periphery.
The engine also includes an arcuate series of gas
no~zles around and partially or completely surrounding the rotor.
They are closely adjacent to the rotor rim periphery with each
nozzle having an axial gas passage providing a high velocity,
and preferably supersonic, blastsof gas relative to the nozzle
e~it into the buckets.
Each nozzle exit is located at and substantially
linearly aligned with the bucket entrances during rotation of
the rotor and there is also provided a blast directing means
for directing substantially all of the nozzle blasts directly
into the bucket entrances for flow over the impulse surfaces
and from the bucket exits.
The invention in its broader aspects pertains to
a pressure gas engine driven by blasts of gas including an
enclosing casing having a gas flow exhaust comprising gas
flow outlet openings of low back pressure relative to the
absolute pressure of the blasts and a rotor in the casing
having a circular rim defined by an outer periphery and
rotatable about an axis of rotation. A single series of
closely adjacent impulse buckets are provided in the
rotor at the periphery with each bucket having an entrance
and exit and with each bucket lying on a chord of the rim
that is adjacent to a tangent to the rim that is parallel
to the chord. Each bucket has an arcuate impulse surface
of substantially constant radius transverse to the direction
of rotation of the rotor, the arcuate surface extending from
an entrance side of the bucket located at the periphery to
an opposite exhaust side of the bucket also located at the
~-~ periphery. Each exhaust side of the bucket exhausts directly
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into the gas flow exhaust of the relatively low back pressure.
The circular rim is provided with a flat, substantially
square recess outwardly of, and adjacent to, each bucket
and the recess is located in alignment with the bucket
entrance and exit sides, the recess extending between the
outer extremities of the entrance and exit sides of its
respective bucket. Nozzle means comprising an arcuate
series of gas nozzles are provided in the c'asing closely
adjacent to the rim, each nozzle having an axial gas passage
substantially aligned with the entrance sides during rotation
of the rotor for providing a high velocity blast of gas
through each nozzle, through the buckets and directly into the
gas flow exhaust in a single pass through the buckets. The
nozzle passages a~e located at and substantially linearly
aligned with the bucket entrances and the nozzle means
comprises blast directing means for directing substantially
all of each the nozzle blasts directly into the bucket
entrances for flow over the impulse surfaces and from the
bucket exits. The gas blast thereby enters and leaves the
rotor at the rim periphery. The blast directing means includes
a flow directing member locating the outer boundary of each gas
blast at the periphery and means are provided for supplying
pressurized gas to all the nozzle means.
In the preferred construction, each arcuate impulse
surface of each bucket, whether the bucket is open or tubular,
extends for about 180 between the entrance and exhaust sides.
Also, in the preferred construction the nozzles are of
rectangular cross section at all points along the central axis
thereof and the buckets are also preferably of rectangular
cross section. The nozzles are so arranged that each nozzle
has a central axis that is on a chord of the rotor that is
closer to a tangent to the rotor rim than is the plane of the
impulse surface of each bucket.
Brief Description of the Drawings
.
Figure 1 is a side elevational view of a pressure
gas engine embodying the invention.
Figure 2 is a sectional view taken substantially
along line 2-2 of Figure 1.
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Figure 3 is a side elevational view taken from the oppo-
site side of Figure 1.
Figure 4 is a bottom view of the embodiment of Figure
3 looking up from line 4-4 of Figure 3.
Figure 5 is a view similar to Figure 2 but illustrating
another embodiment of the invention.
Figure 6 is a fragmentary siae elevational view partially
broken away and partially in section of one embodiment of the
engine.
Figure 7 is a side elevational view partially in section
of an embodiment of the rotor of the engine.
Figure 8 is a partial sectional view through the rotor
of Figure 7.
Figure 9 is a fragmentary sectional view of the engine
embodiment in the vicinity of the rotor and nozzle plate and illus-
tràting schematically a single nozzle.
Figure 10 is a fragmentary side elevational view partially
in section of a fu~her embodiment of the rotor.
Figure 11 is a fragmentary sectional view illustrating
another embodim`ent of the rotor.
Figure 12 is a fragmentary sectional dew taken substan-
tially along line 12~1~ of Figure 11 showing flow of the gas blast
relative to a rotating bucket.
Figures 13 and 14 are similar to Figures 10 and 11 but
illustrating a ~urther embodiment.
Figure 15 is an enlarged sectional view through a portion
of the rotor and the surrounding nozzle plate of an embodiment of
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the invention and illustrating converging-diverging nozzles.
Figure 16 is a view similar to Figure 14 but illustrating
yet another embodiment.
Figure 1~ is a plan view of a portion of the rim of the
rotor of Figure 15 illustrating a series of three tubular buckets.
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Flgure 18 is a detail sectional view taken substantially
along line 18-18 of Figure 16.
Figures 19-21 are each fragmentary sectional views illus-
trating different embodiments of nozzle plates.
Description of the Preferred Embodiments
.
In the embodiment of Figures 1-4 the gas engine 10 com-
prises a casing 11 co~prising two ~lves bolted together with one
comprising an entrance scroll side 12 and the other an exit scroll
side 13. The gas as shown at 14 enters the entrance scroll, passes
through the nozzles and buckets and exits rom the engine as shown
by the arrow 15.
Held in the casing 11 is a drive shaft 16 supported on
spaced ball bèàrings 17 and the entrance scroll side 12 has pro-
jecting therefrom an axial tubular extension 18 to which the shaft
16 is sealed by a pressure deformable seal ~9.
The opposite end 22 of the shaft 16 which is opposite
the seal 19 is enclosed within a cap 23 bolted to the casing 11
as by bolts 24. The shaft L6 has an end portion 25 adjacent to
but spaced inwardly of the extreme end 22 and providea with an
20 annular flange 26 to which is bolted a circular rotor 27 as by a
series of bolts 28. The drive shaft 16, the tubular extension ~ :
` 18, the seal 19, the cap 23 and the rotor 27 are all coaxial about
a central axis of rotation 33.
Between the entrance side 12 and the exit side 13 of
the casing 11 there is provided an annular nozzle plate 29 that
contains a closely adjacent ser~s of nozzles 30 as shown in the
detail nozzle plate sectional view of Figure 6. The side plates ~:
12 and 13 and the nozzle plate 29 are held in assembled relation-
ship as shown in Figure 2 by a peripheral series of bolts 34.
The entrance scroll side 12 has a large volume scroll
passage 35 leading from an entrance extension 36 for flow of the ~
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entering gas 14. The exit scroll side 13 which is assembled in
facing relationship with the side 12 and with the nozzle plate
29 therebetween, as explained above, contains a large volume scroll
37 leading to an exit extension 38 for the exiting gas 15.
As is shown in Figures 6 and 9, each nozzle 30 of this
embodiment has a converging entrance 39, a throat 42 and a di-
verging exit 43 that define an axial gas passage for providing
a high velocity blast of gas into the rotor buckets. This gas
blast 54 which is ordinarily supersonic relative to the nozzles,
in this embodiment, lies along the central axis 44 of each nozzle
30.
As shown in the rotor embodiment of Figures 7 and 8,
the rotor 27 is provided with a single series of closely adjacent
impulse buckets 45 with each bucket having an arcuate impulse
surface 46 of substantially constant radius transverse to the
direction 47 of rotation of the rotor 27. These bucket surfaces
46 extend` from an entrance side 48 of each bucket that is adjacent
one side 49 of the buckets to an opposite exhaust side 52 that
is adjacent the opposite side 53 of the buckets. The gas blast
54 entexs each bucket at its entrance side 48 for su~stantially
unrestricted flow around the arcuate impulsè surface 46 and from
~he exhaust side 5~ of each bucket.
As can be seen in ~igure 2, each exhaust side of each
bucket exhausts directly into a volumetric section of low gas
back pressure as illustrated by the exit scroll passage 37 of ;~
large cross sectional area and the similarly large exit extension
38. The back pressure is defined as pressure equal to or greater
than the design nozzle blast pressure illustrated at 54 in Figure
9. This blast pressure in many cases is equal to ambient atmos-
pheric conditions. However, blast pressures of 50-100 psig or
more may be desirable in certain installations in which case the
low back pressure wOula be correspondingly greater.
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The nozzle means comprises the nozzle plate 29 and the
arcuate series of nozzles 30 each providing a high velocity blast
of gas. The nozzle plate is retained in position by a nozzle
plate retainer ring 31 (Figure 2). Each end of the shaft 16 is
provided with a spline drive 40 and surrounding the shaft 16 in-
wardly of the ball bearings 17 is a bearing cap and grease seal
20.
The nozzle means also comprises a blast directing means
(Figure 9) for directing substantially all of each blast 54 di-
10 rectly into the bucket entrances 48 for flow over the impulsesurfaces 46 and from the bucket exits or exhaust sides 52. This
blast directing means includes a flow directing member 55 which
is an integral part of the nozzle plate 29 locating the outer
boundary of the gas blast 54 at the surface 56. This boundary
surface 56 and thus the outer boundary of each gas blast is sub-
stantially at a tangent to the rotor periphery 57 as illustrated
in Figure 9.
The gas entrance extension 36 and the entrance scroll - -
passage leading to the nozzle entrances as illustrated by the gas
20 flow arrow 58 comprise means for supplying the pressurized gas
14 to àll of the nozzle means 30 while the exit scroll 37 and the
exit extension 38 comprises means for exhausting spent gas. :~
As is illustrated in Figure 7 the adjacent buckets 45
are separated from each other by a wall means 59 forming an in-
tegral part of the rotor 27 with each wall means having a thin .
edge 62. This thin edge divides the gas blast 54 for flow into
adjacent buckets 45 as the thin edge passes the nozzle exits 43. . :~ -
As is shown in Figures 7 and 8 the inner surface 65 of each bucket
45 that is closer to the axis of rotation 33 is convexly recessed
30 so that the nozzle blast 54 across this surface provides a low
pressure airfoil-like surface adding to the rotational torque
developed by the rotor. The central nozzle axis 44 wh~ch for pur- . .
poses of illustration in Figure 9 coincides with the arrow 54 .
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ndicating the gas blast lies on a chord that is closer to a
tangent to the rim or periphery 57 of the rotor than is the plane
of the impulse surface 46 of each bucket.
The large volume gas flow passages 36, 35, 37 and 38
permit relatively free flow of gas to the nozzles 30, through
the rotor buckets 45 ~d from the buckets after the pressurized
gas has acted upon the rotor. The gas thereby rotates the rotor
in a very efficient way and at the same time greatly reduces the
gas temperature so that the exiting gas 15 is much cooler than
the supply gas and may actually produce a refrigerating effect.
Each nozzle exit 43 is linearly aligned with each bucket
entrance 48 during rotation of the rotor. In the preferred engine
or turbine, as illustrated, each buc~et 45 has àn impulse surface
~6 extending for about 180 so that when the rotor 27 is in the
position shown in Figure 9, for example, the high velocity gas 54
from each nozzle 30 enters each bucket at an entrance s}de 48,
flows around the impulse surface 46 and then leaves the bucket at
the exhaust side 52. The very high efficiency of operation and
the very high horsepower developed per unit of gas flow rate are
20 caused by a combination of the above 180 flow of the gas relative
to the rotor, the entering of the gas into the buckets as close
to rotor tangent as possible and the insuring of this tangent flow
-
of gas by providing the blast confining wall surfaces 56 (Figure
9~ for each nozzle. ` ;
Thus a 4.75 inch diameter turbine embodying this inven-
tion and supplied with air at 100 psigand 80F. at the turbine
inlet produces 7 horsepower at an air consumption of 105-120 SC~M.
m e turbine therefore used only 15-17 standard cubic feet per
minute of air per minimum flow rate per shaft horsepower developed.
30 This is believed to be about one-half or less of the flow rate per
horsepower achieved in conventional impulse gas turbines under
these conditions.
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In the preferred construction as illustrated the
flat surface 65 leading to each bucket 45 is sloped toward
the bucket impulse surface 46 as shown for example in Figure 7.
This sloped surface 65 is recessed from the circular rim and
is approximately square in plan view with the trans-
verse dimension being defined substantially by the bucket diameterand the length of this surface defined by the distance between
successive narrow sharp edges 62. In one example of a 4.75 inch
diameter by 0.562 inch wide rotor thirty equally spacéd buckets
45 were provided in the rim 66 of the rotor 27 and twenty equally
spaced nozzles 30 in a surroun~ng nozzle plate 29.
It is bèlieved that the principal causes for the high
eficiency of this engine and the high horsepower per unit gas
flow is a converting of the pres~re gas to dynamic gas flow 54,
the directing of sùbstantially all of each blast~ of gas into the
buckets 45 substàntially tangentially to the rotor, the sweeping
of the gas blast across the arcuate impulse surfaces 46 and from
there out the exit or exhaust side 52 of each bucket with both
the entering gas blast 54 and the exhaust gas flow illustrated
20 at 63 in the embodiment of Figure 12, which is common to all em-
bodiments, substantially on a tangent to the rotor and su~s~
tially parallel to each other and at right angles to the axis of
rotation 33 into a non-restrictive exhaust port.
The high performance of this turbine is achieved by
reducing the speed of the nozzle blast illustrated at 54 relative
to the ground to as low a value as possible as a result of its
path through the rotating turbine buckets.
Another very important and contributing factor to the
high efficiency and high horsepower per unit gas flow achieved
30 appears to be the directing of the exhaust gas with substantially
no flow restraining obstructions away from the rotor. This is
achieved by having the exit scroll passage 37 and the exit exten-
sion 38 restriction free and of large cross sectional area,
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The boundary surface illustrated at 56 directs the gas
blast which has a finite thickness so that the entire thickness
of the blast crosses the peri~ry 57 of the rotor 27 at a small
angle which is as close to tangent to the rotor as possible.
A graphic example of the th~ry of the problems overcome
by the impulse turbine or pressure gas engine of this invention
can be seen in contrasting the well known Pelton wheel type
hydraulic turbine. A typical turbine of the Pelton wheel type
could be supplied with water at a head of about 1500 feet as by
a dam of this height. The nozzle would then eject water at a
speed of about 300 feet per second relative to the ground to im-
pact on buckets moving at about lS0 feet per second relative to
the ground. Under those conditions, a peak efficiency of 93%
could be expected including an expected 7% loss. Part of this
7~ loss in efficiency is due to the acceleration of the air sur-
rounding the Pelton wheel engine by the fan-like effect of the
impulse buckets in the rotating rotor which are moving at about
100 miles per hour. As atmospheric air has only 0.1% the density
of water, approximately, it can be seen that if the Pelton wheel
. . . ~ - .
~0 were operating with the rotor submerged in its own working fluid,
namely water, instead of the much less dense air there would be
a disasterous loss in performance because of the greater density
and therefore drag on the rotating wheel. This loss would be
primarily due to the acceleration of the water surrounding the
wheel ~y the impulse buckets acting on the wheel.
The rotor 27 of this invention operating submerged in
air or gas, i a gas other than air is used, provides a rim speed
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of rotation 47 relative to the ground approaching one-half the
nozzle blast 54 speed. At peak efficiency for a preferred con-
3~ ~erging-diverging nozzle supplied with air at 80~F., 100 psig ex-
hausting to atmosphere, the nozzle blast 54 speed relative to the
ground will reach about 1600 feet per second. The rim speed 47
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of the rotor relative to the ground will approach about 800 feet
per second at peak efficiency. The bucket edges 62 will there-
fore have a speed relative to the air in which they are submerged
of 800 feet per second. This air may become quite cold, as low
as -125F. or even lower. Under these conditions the local Mach
number of the surrounding air relative to the rim is nearly one.
As with a Pelton wheel submerged in water, it is possible to
suffer great efficiency losses if the buckets significantly
accelerate the surrounding air but the open impulse buckets of
this invention reduce the windage or pumping losses associated
with circulation of atmospheric and exhaust air by the rotor and
the rotor buckets.
It has also been found that the dynamic losses asso- -
ciated with partial flow and full flow operation of the turbine -~
may be further reduced by providing a bucket passage which is
only as large i`n cross sectional area as is required to contain
the blast 54 from the nozzles 30 relative to the bucket passage.
This is achieved in the illustrated embodiments of Figures 10-18
(to be described hereinafter) which illustrate tubular buckets.
This reduction of dynamic losses in the tubular buckets is believed
to be due to the elimination of the open volume of the bucket
which is that area illustrated at 68 in Figure 7 as this area is
not needed to convert thè gas blast to shaft horsepower as this is
done by the gas blast 54 sweep over the arcuate impulse surfaces
46. This aerodynamically unnecessary volume of the bucket may
comprise 50~ or more of the entire bucket 45 volume. During high
speed this unused open space tends to interact with the gaseous
atmosphere surrounding the rotor and thus the buckets thereby
cause dynamic losses due to the fan-like effect of the unused open
space on the surrounding atmosphere. By providing the tub~ar
buckets 73 this unused open space is eliminated and thus during ~ -
full flow conditions the gas surrounding the rim 66 of the rotor
no longer flows inwardly of the rotor periphery to interact with
the open bucket surfaces.
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The first embodiment of the tubular bucket rotor is
shown in Figures 10-12. Here the rotor 69 has located in its
peripheral rim 66 a series of buckets 73 that are the same as the
buckets 45 of the first embodiment except each is tubular with an
entrance 74 for receiving the gas blast 54, an arcuate tubular
impulse section 75 and a tubular exit 76. Both the tubular en-
trance 74 and exit 76 are substantially parallel to each other,
lie on approximately equal chord as close to tangent as possible
to the rotor rim, and are atright angles to the axis of rotation
77 of the rotor 69. In this embodimènt the width of the tubular
impulse section 75 decreases or converges to about the center 78
of the bucket and then increases in section width or diverges to
the exit.
In the embodiment of Figures 13 and 14 the rot~ 79 also
contains a series of tubular buckets 82 similar to those in the
last previous embodiment but here each bucket is diverging in
that it increases in width gradually and uniformly from the en-
trance 83 to the exit 84.
In the embodiment of Figures 15-18 there is disclosed
in enlarged detail the relationship of the nozzle plate 80 to a
rotor 85 having a rim 86 provided with a series of tubular buckets
87. Each of these buckets so far as the tubular configuration is
concerned is similar to those of the embodiment o~ Figures 10-12
and in all other respects to the open buckets 45 of the first
embodiment. ~hus each nozzle 90 in this embodiment has a con-
verging entrance 88, a restricted throat 89 and a diverging exit -
92 with all exits having a common inner periphery 93 that is circu-
lar and very closely adjacent to the outer periphery 94 of the
rotor 85. Here, as in the other embodiments, the nozzles 90 are
of rectangular cross section. This embodiment in Figure 15 shows
how the outer limit 95 of each nozzle exit 92 spans more than one
bucket entrance 96. Thus in the illustrated embodiment, there are
45 buckets and 30 nozzles. In this embodiment the buckets 87
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are of uniform width from the en1rance 96 around the ~ull 180
sweep of the buckets 87 and through the exit 97.
The tubular bucket structure as illustrated in these
embodiments of Figures 10-18 is preferred because it improves the
conversion of the kinetic energy of the gas blast to shaft 16
horsepower in three principal ways. First, this construction fur-
ther reduces the power required to spin the rotor at a speed
recluired for the most efficient conversion of the kinetic energy
of the nozzle blast 54 to horsepower and, second, by reducing
10 windage losses on the rim, third, by providing a tubular guide for
the gas blast as it changes directions in the bucke. passage gas
velocity losses are minimized so that the force exerted by the
blast passing through the bucke. is increased and more nearly
approaches the maximum that can be achieved.
Another very important feature of the tubular bucke~
construction which improves the efficiency of operation of the
turbine is the greatly increased strength of the tubular hl7cket
when compared to the open style bucket of the e~bodiment of ~igures
1-9. This greatly increased strength is the result of signif-
icantly shortening the unsupported span of the bucket surface atthe entrance just inwardly of the sharp bucket separating edge
98 which is similar to the sharp edge 62 in the flrst embodiment
` that separates the adjacent buckets. In the open arrangement of
the first embodiment this span is equal to the diameter of the
substantially radial impulse surface 46. However, in the tubular
bucket embodiments the span is supported for a substantial dis-
tance betwcen the entrances and the exits of the buckets. Thus
when a gas such as steam, natural gas at high pressure or air at
elevated temperatures and pressures is used, the rotor with the
tubular buckets may be operated at much greater rim speeds required
to convert efficiently the kinetic energy of the resulting high
velocity nozzle blast to shaft horsepower.
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In all embodiments in order to direct all of the gas
blast from each nozzle completely into each bucket for sweep
across the respective impulse surface the exit or exhaust end of
each nozzle should be substantially no greater in width than the
width of the entrance to each bucket.
In addition, the provision of only a single row of
buckets comprising a single stage as illustrated in all embodi-
ments with no re-entry and with relat~ely free flow exit from the
buckets makes an important contribution to the very high efficiency
achieved.
The provision of the flow directing member illustrated
at 55 in the first embodiment of Figure 9 and at 100 in Figure
15 and which is also shown in all other embodiments confines the
gas blast (e.g. 54) on three sides with only the rotor side being
exposed so that all of the gas blast is directed to the rim of
each rotor at the periphery thereby preventing any gas from being
redirected out of the bucket by contact of the gas with the ad-
jacent rotating surface of the buckets. This confinement of the
gas blast is of particular importance in the tubular bucket con- -
20 struction as it insures that substantially all of each gas blast
enters the buckets at the proper angle and that all the gas passes
over the arcuate impulse surfaces of the buckets (illustrated at
46 in the first embodiment) so as to utilize the entire flow of ` -
the bucket. These three confining sides of each flow directing
member 55 comprise the outer wall surface illustrated at 56 and
opposite parallel confining sides 99 (Figure 6). These confining
sides further prevent sideways dissipation of the energy of the
blast.
Figure 5 illustrates an embodiment which is exactly the
30 same as the em~odiment of Figures 1-4 except that here the exit
scroll side 13 is omitted permitting the exit gas ~low 93 to pass
directly to the exterior 104 without going through an exit scroll.
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Figure 15 illustrates a typical converging-diverging
nozzle plate 80. In this plate the converging entrance 88 is at
a 32 angle, the throat 89 is 0.031 inch long and the diverging
exit 92 is at a 15 angle. Although the converging-diverging
shape o~ each nozzle is preferred because of the resultant high
speed gas blast which may be as great as supersonic the turbine
can also be used with other shape nozzles to produce very high
efficiency. Thus in the Figure 19 embodiment the nozzles 105
have parallel tops and bottoms while in Figure 20 the nozzies 106
10 are converging toward the rotor and in Figure 21 the nozzles 107
are diverging toward the rotor.
As mentioned earlier, one ofthe reasons for the high
efficiency, as expressed in cubic feet per minute per horsepower,
of the engine or turbine of this invention is that the pressurized
gas is not subjected to a long travel path as is the case with
the re-entry type system to convert the gas energy to shaft h~rse-
power. This invention rather provides as short as possible a path
of travel of the gas through the buckets and exhausts the gas
immediately into an area of relatively low gas pressure so as to
20 avoid excess back pressure.
Although several statements of theory have been made
herein, the invention is not to be limited by any of these.
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