1. No category

July 30, 1929.
|__ F, MYQODY _
'
HYDRAULIC
POWER
PLANT
Filed May 26. 1920
YI rIY-_
&
I
’
I
1,722,438 ,
'
I
'7 Sheets-Sheet
1
‘g
- July so, 1929.v
L. F. MOODY
'
'
HYDRAULIC POWER PLANT
Filed May 26. 1920
>
'7 Sheets-Sheet
2
46
v
/
.
49
// 521/ /
A6”
{I 29 ’/
i
’
1,722,438
|
,
\\
45
I \
aw’
6
/
/
@
/
//
I
60
/
la.
I
5
Am; 7;- 741
M17“ @060“,
;
1,722,438
July 30, 1929. '
1.. F. MOODY
‘
HYDRAULIC POWER PLANT
'
7 Sheets-Sheet
Filed May 26, 1920
55
5_
,
.
z
Q. //
I
/////
7////
4
July 30, 1929.
1,722,438
L. F. MOODY
HYDRAULIC POWER PLANT
'
Filed May/26, 1920
.
.
7 Sheets-Sheet '
5 _
A
'7'j4/44/44W/
7/\L_____
/5.'
H“
70.
__
\
*
jW/ww'
'
I
‘
' v///
'
4
5514/4?‘ wozvic/ugrw
i‘lm't'”
"
July 30', ‘1929.
'
L. F’. MOODY
'
HYDRAULIC
'
1322338
POWER PLANT-
Filed May 26, 1920
I
7 Sheets-Sheet
e
I
a
I
-|
_ I____J___________
v
..
1,722,438
Patented July 30, 1929.
UNITED STATES FA'E'ENT @FFEQEQ
LEWIS FERRY MOODY, OF PHILADELPHIA, PENNSYLVANIA.
HYDRAULIC POVJER PLANT.
Application ?led May 26, 1920. Serial No. 384,402.
This invention relates to hydraulic power
Fig. 8 is a vertical sectional view of a vfur
plants and particularly to hydraulic turbine ther modi?cation illustrating a different ar
installations in connection with dams, for rangement of the spillway passages.
instance where the power house is built as a
10
part of the dam.
The object of the invention is to provide
a hydraulic turbine installation which will
be strong and compact and el?cient in the
handling of the ?ow and adapted to form
part of a dam and particularly of a dam sub
j ected to abnormal high water or flood condi
Fig. 9 is a horizontal sectional view-on line
9,9ofFig.8.
I
3
Fig. 10 is a horizontal sectional view on line
10, 10 of Fig. 8.
In the speci?c embodiment of the inven
tion shown in Figs. 1, 2 and 3 a dam D has
a crest C between the head water H and the
tail water L and the head water face of the
tions requiring an over?ow of the excess wa
dam is extended backward by piers P between
ter past the power station.
which are the flames or passages 13 to the tur
(35
In many power plants, particularly'for low bines and the spillway. The head gates M
sliding in ways M of the piers P and seating
20
and medium heads, it becomes a serious prob
lem to handle these abnormal ?ood condi
tions, for in addition to providing for the
passage of the water which is to be'utilized
in the turbines there must be additional dis
against the floor 15 of the intake control the
flow to these passages 13 and auxiliary spill
way gates S are provided above the dam crest
charge means capable of handling in the ma
jority of developments quantities of water
greatly in excess of the quantity normally
?owing in the stream and far beyond the dis
charge capacity of the turbine passages. The
ner R and out through the draft tube F open
C. The-?ow from the head water H passes
through passage 13 to the intake passage I "
and around to and through the turbine run
ing into the outlet passage 0 discharging in
to the tail water L below the tail water level.
usual method of disposing of the excess water The runner R has its shaft 20 extending up
is the provision of long spillway sections in ward through the crest of the dam and
the dam over which the water can pass. In through the spillway passage A thereabove to
drive the generator G on the power house ?oor .
30
power developments in which the power house
is built a part of the dam, it often becomes
difficult to provide a length of dam suf?cient
to furnish the necessary length of spillway in
addition to the space required for the power
house and in such cases it is particularly de
sirable to carry overflow or spillway passages
or generator deck supported for instance by,
bridge or arch 21. Around the shaft 20 is 85
the cylindrical pit T extending downward '
from the crest C and having a cover plate
22 at the crest level and a wall 23. The bottom
of the pit Wall 23 is provided with a conical
through the portion of the dam occupied by portion 2a resting on speed ring 25 support
90
ing the. turbine head cover 28 and in turn
In the accompanying drawings illustrating supported upon the ledge surrounding the _
the power house itself.
speci?c embodiments of the invention
~10
draft tube F. In the upper portion of the pit
Fig. 1 is a vertical sectional View of a tur T braces 26 support a shaft bearing 27 and
bine installation taken in a direction at right similarly the turbine head cover 28 in the
angles to the general direction of the dam.
bottom of the pit supports a shaft bearing
Fig. 2 is a horizontal section of Fig. 1 on 29 and also houses the operating means for the
line 2, 2.
' adjustable guide vanes 30 in the intake pas
Fig. 8 is a horizontal section of Fig. 1 on sage, these operating means comprising the
control ring 31 connected to turn the stems 100
line 3, 3.
of
the guide vanes and moved by fluid pres
Fig. 3‘L is a section on line a, a of Fig. 3.
sure in cylinders 32 connected by piping to
Fig. 3b is a section on line b. b of Fig. 3.
Fig. 4 is a view similar to Fig. 1 illustrating be controlled by a governor preferably on the
power house ?oor above.
a modi?ed installation.
The walls of the pit T comprise the cast 1(5
Fig. 5 is a horizontal sectional view on line
5, 5 of Fig. 4.
iron conical section 24 bolted to the speed ring
Fig. 6 is a vertical sectional elevation of a 25 and provided at its top with the plate steel
still further modi?cation taken on line a b 0 barrel 23 from this point up to just below the
of Fig. 7.
Fig. '7 is a section on line 7, 7 of Fig. 6.
intermediate bearing 27 where a second cast
iron section 23’ is set in the concrete structure
110
2
1,722,438
of the dam. A tube 35 extends upward from the water approaches the turbine axis in a
the pit cover plate 22 and around and pro spiral curve and then is gradually turned in a
tecting the shaft 20 from the flow in spillway helical path at 46 so that it proceeds toward
A. This tube also provides a convenient pas the turbine with ‘a motion compounded of
sageway for access to the pit T so that the rotation about the turbine axis and a vertical
bearings and operating parts therein may be downward motion. The top 47 of the intake
easily inspected and kept in adjustment and I is formed to approximate a helicoidal sur
repair. lVhenever it should be necessary to face or screw thread terminating after a ro
remove the working parts of the turbine the tation of 3,6 0 in an edge 48 just above the
cover plate 22 would be removed from above turbine proper. The lower surface 419 of the
together with the tube 35 surrounding the intake curves gradually from thehorizontal
shaft, the generator G having ?rst been re floor 15 of the gate chamber down to the edge
moved. In the embodiment shown in Fig. 1 4-8, and by this design the sudden bend or
this could be done by closing the spillway elbow around which the water would have to
" .gate S either with or without closing tae head flow in turning from the horizontal to the
80
gates M. IVhenever the local ‘conditions vertical direction, if no spiral guide walls
should so require the spillway gate S could _ were used, is avoided. It will be seen from
be arranged on the downstream side of the Fi g. 1 that if the water should turn from the
20
turbine pit T that is at or slightly beyond the horizontal to the vertical in planes parallel
downstream end of the crest C of the spillway to that of the ?gure without rotating about
A in which case it would be necessary to close the turbine axis, this right angle bend would
the head gates M whenever any parts of the cause a loss ‘of head and a disturbed condition
turbine are to be removed.
7 In the structure of this invention a spill
30
way section A of the dam D is provided with duly abrupt, as shown by the small radius of
in the length of the power house and at the the lower wall, marked 15’, Fig. 1. By car“
same time provision is made for removing the rying the water in a. spiral, the curvature in
working parts of the turbine vertically into the direction of flow is made much more gra d
the power house so that these parts may be ual. Moreover, if the water were allowed to
handled by the power house crane. “Then enter the vertical portion of the conduit hori~
the open air type of generator is adopted the zonta-lly, it would have to pass around both
turbine parts can be" handled by the gantry sides‘ of a circular turbine pit- and then turn
lcrane which would be supplied to run the into the downward direction, and there would
95
length of the generator deck. the same crane almost inevitably be eddies and surging pro
being used to handle both the generators and duced at the downstream side of the circular 100
turbines. In regular operation and when the pit. The downward flowing water would
head water level overtops the spillway crest subsequently be required to assume a rotation I
C the excess water will pass out through the either during its passage tarough the turoine
spillway A over the cover plate 22 of the speed ring or before reaching this point.
b
123 U!
of the water entering the turbine. The cur
vature would necessarily be in most cases'un» .
23
1
pit T.
If the water is turned, from horizontal to ver
The arrangement of this invention places tical without conducting it in a spiral course,
the various parts of the turbine installation the flow lines would be practically indetermi—
advantageously and compactly. The genera nate, and uncertain ?ow conditions would re
tor deck is above water level giving clear ac sult. In the turbine casing of this invention
all
cess to the generators at all heads and pro the velocity can be closely calculated
viding plenty. of surrounding space which points of the ?ow between the intake and the
110
would not be the case if the generators were entrance to the turbine.
The useful water ?ow for the turbine after
sunken below the spillway level. Immeti
ately below the generators is the spillway passing through the speed ring 25 and adj ust
passage A clear but for the single tube able guide vanes 30 enters between the blades
35 extending upwardly through it. Be of runner R and is discharged axially there
low the spillway crest is the pit T sur from. In turbines of high specific speed such
rounding the shaft 20 and providing easy as would more usually be employed in such
access to all the turbine parts at the bottom developments involving low heads, this axial
55
60
of this pit where the turbine with its operat out?ow will also have a considerable whirl
ing means is compactly assembled. The water ing motion or rotation of the discharge stream
inlet I to the turbine surrounds the pit wall 93
a whole around the turbine axis. The dis
and utilizes the outer wall surface as its inner charge is received by the spreading draft tube
surface so that all the elements of the turbine F comprising anupper substantially straight
?t compactly together. Similarly the draft portion of increasing cross section and a low
tube F at its lower end is surrounded by the
out?ow passage 0 leading the discharge to
the tail water L.
In Fig. 1 the turbine casing or intake 1
65
er portion ?aring outward therefrom and ex
panding radially with continuing increase. in
cross section so that the flow is turned'sym
metically and smoothly into the horizontal
consists of thespiral inlet 4L5 through which direction and has a large part of both its axial
120
125
3
1,722,438
and whirling components converted into pres
charge passage to carry the water under the
sure head at the entrance to the horizontal‘ spillway section of the dam makes it desirable
out?ow O which continues to gradually in
to use the spreading type of draft tube rather
crease in cross section to effect the ?nal con
than the elbow type.
_
The helical formation of the intake passage
version of discharge velocity into pressure
I provides a supporting wall wrapping
head at the tailwater L.
The outflow passage 0 surrounds the. dis around the pit wall 28 and while in the speci?c
charge edge of the draft tube by a pair of op embodiment shown in Fig. 1 this passage
positely directed half spiral passages 60 and turns through substantially 360° it may turn
10
61 forming collection chambers for the ?ow through a greater or less angle and have a
from the draft tube. These collection cham correspondingly smaller or larger pitch or be bers 60, 61 extend upward as shown in dotted otherwise modified for instance as shown in
lines in Fig. 1 around the suspended conical Figs. 4, 5, 8, 9 and 10. To reduce the angle
draft tube walls 62 and 63 on each side, the and increase the pitch reduces somewhat the
discharge side of this draft tube wall being amount of concrete and form work required
extended as a central pier 65 for providinga in the construction but at a sacrifice of
continuous foundation for the structure smoothness of curvature at the entrance to
the casing. The choice of the angle would
'
The central pier 65 thus separates the flows depend upon the economic relation between
from the collection chambers 60 and 61 as cost and efficiency in each particular instal
above.
these ?ows pass into the discharge end of the
outlet passage 0. It will be noted that the
lation.
"
In the arrangement shown in Figures 4
passages 60 and 61 he partly above the lower and 5, the design of the intake 1, and easing
end of the draft tube, the material of the up has been slightly modi?ed by placing the edge
per wall of the tube being formed as lips 80 14:8 ninety degrees from its position in Figs.
projecting laterally from the main portion of 1 and 2. The edge is here placed on the
the walls 62 and 63. By locating the'outflow center line of the turbine in the direction of
passages within the outer limits of the draft flow, that is, immediately in line with the
tube an economy of space is secured. The center of the intake 1, so that the upper wall
30
walls 62 and 63 as shown in Figs. 3 and 10
have a general elliptical form in section.
The draft tube of this invention thus has a
vertically directed axial inlet F and a hori
zontal radially directed outlet 0 at an angle
to each other and between these sections is the
bend or elbow formed by the spreading pas
sage. and collecting chambers described. The
147 of the casing is carried to less than a
complete revolution. This reduces some
what the amount of concrete and form work
90
95
required in the construction, and while it
gives shorter and not quite so gradual a curv
ature at the entrance to the casing, might be
preferred in some installations.
In Figs. 6 and 7 a further modi?cation is
upstream walls of the collecting chambers 60, shown, having its intake passage in two half
61 form the end wall of the horizontal outlet spirals 70 and 71 developing in opposite direc~
portion of these collecting chambers 60, 61 tions from edge 54: of the crest G, the edge 78
and form relatively deep side portions which here being placed in line with the center of
gradually decrease in depth in an upstream the intake but on the downstream side of
100
105
direction toward the upstream wall. Be the turbine pit T. Thisarrangement is more
tween these collecting chambers 60, 61 and economical in amount of concrete required,
45
disposed longitudinally of the outlet portion and in some instances would probably furnish
as much guidance and as smooth lines of flow
jects downwardly from the roof of the outlet as it would pay to adopt. The curvature
(see Figs. 3a and 3b) and comprises towards from horizontal to vertical at entrance is here
as shown in Fig. 3 the concrete formation pro
the free end of the outlet the pier member 65 more'abrupt than in Figures 1 to 5, but the
extending all the way down to the floor of the formation of eddies behind the pit wall is
outlet. As shown in Fig. 3 this projecting prevented, and definite lines of flow are pro
110
115
portion extending downward from the roof vided at all points. In this arrangement,
of the outlet tapers gradually to become nar— however, the water will approach the en—
trance to the turbine proper without whirl,
The use of the spreading type of draft tube and this whirl will be introduced by the speed
also offers important advantages when used ring vanes 25 and 30. Fig. 7 shows in sec
with the arrangement of turbine here. de tion the form of the tube 35 surrounding the
row toward the free end of the outlet.
120
scribed, since it would be objectionable to shaft, which would be the same in the ar
.
use the older type of draft tube involving an rangements of Figs. 1 to 5.
elbow or bent passage, since the elbow type
Figs. 8, 9 and 10 show a still further em~
of draft tube would discharge the water into bodiment of the invention in which the piers
the long horizontal discharge passage with P’ supporting the generator floor are placed
too high a velocity in the. water and with too in line with the turbine axis instead of half
much disturbance. That is. the necessity of way between the turbines as in Figs. 1 to 5.
providing a long straight horizontal dis Spillways A’ between the piers are thus pro 130
4
1,722,438
vided between the turbines and piers may be when itcan be used on account of the greater
extended outward beyond the inclined face 'accessability of the turbine pit, but the ar
of the dam ID on the discharge side to form rangements of Figures 1 to 7 may be more
the buttresses U. The spillway crest C’ has adaptable for dams under high head between
its'edge located at 55 just in advance of the the portion of the dam on the upstream side
spillway gate S’ and below this crest the of the turbine and the overfall section down—
intake passage I’ leads downward and side stream from the turbines, since in addition
wise on inclined spiral lines to a helical por
10
70
to the thickness of concrete between the tur
tion surrounding the turbine pit T’ and ter bine casings, the intermediate piers provide
n'iinating in edge 118’. It will be noted that added connection.
this edge 48’ is positioned differently from
1. In a hydraulic turbine’ installation the
the edge 48 of Fig. 1, being terminated above
the conical casing 24, and the upper end of combination with a turbine runner, of an in
the intake passage I’ is carried off at an take passage for the flow to said runner, a '
[5
angle to the passage 13’ between the piers P’. ‘draft tube for the flow from said runner con'r
In order to provide a continuous path for prising a circular wall flaring at its lower
the'stresses developed in the dam down to the
foundation the central pier 65’ in the dis
charge is made long and large in cross sec
v tion and the walls 66 between the discharge
80
end to turn the flow to the horizontal, and
separate collection chambers for the ?ow
from said draft tube extending upward and
overhanging the edges of said draft tube
passages of adjacent units are made‘ nar~ wall.
2. In a hydraulic turbine installation the
The load from the central piers P’
carrying the generators and power house will combination with a turbine runner, of anin
thus be transmitted directly in a vertical take passage for the flow to said runner, a
draft tube for the flow from said runner com
plane to the foundation.
rower.
SH)
‘With the spillway passages thus located be prising a circular wall flaring at its lower
tween the units the ?ow is not required to pass end to turn the flow to the, horizontal, and
over the pit T’ of each unit. The pits T’ separate collect-ion chambers on each side for
can thus be continued above the head water the flow from said draft- tube extending up
level as shown and the turbine parts can be wa "d and overhanging the edges of said
removed at all times. The open top pit T’ draft tube wall.
3. In a hydraulic turbine installation the
is also advantageous in avoiding the use of
the submerged cover plate 22 and also in combination with a turbine runner, of an
avoiding all obstruction to the ?ow through intake passage for the flow to said runner,
100
the spillways A’. The top surrounding wall a draft tube for the flow from said runner
T’ also directly supports the generator and comprising a circular wall flaring at its lower
in this construction a continuous tubular end to turn the flow to the horizontal, and
separate collection chambers on each side for
formation of the pit from top to bottom
forms a rigid construction retaining the tur
bine parts in accurate alinement. It is ob
vious that in many instances of repairs the
closing of the adjustable guide vanes or
w'cket- gates 30 will be all that is necessary
and that the flow through the spillway may
the flow from said draft tube extending up
ward and overhanging the edges of said draft 105
tube wall and connected to the tail water by
an outlet passage.
I
it. In a hydraulic turbine installation the
combination. with a turbine runner, of an in
be maintained while repairs are going on. take passage for the flow to said runner, a
In all of the embodiments shown the struc draft tube for the flow from said runner com
ture provides for direct access to and re prising inner and outer circular walls form
IH)
moval and replacement of the turbine parts ing an annular draft tube flaring outwardly
and at- the same time leaves large spillway toward the horizontal, and separate collec
54)
~11 CR
spaces through the power house. The tur tion chambers for the flow from said draft
bine parts are compactly assembled in the tube extending upward and overhanging the
lower portion of the pit and the generally edge of the outer wall of said draft- tube.
5. In a hydraulic turbine installation the
circular outline of the pit is maintained with
the gate operating cylinders completely
combination with a turbine runner, of a draft
housed within it. The water passages for tube for the flow from said runner compris
the flow through the turbines are also large ing a circular wall flaring outward at its low
in section and smoothly curved to e?iciently er end toward a horizontal direction and sep
handle the ?ow and the combination of the arate collection chambers surrounding said
turbine structure with the dam provides c011 wall and overhanging the edges of said wall,
120
tinuous supporting columns reaching from the upper surface of each of said chambers 3
increasing in elevation in passing around the
the generator deck to the foundation.
Each of the embodiments shown will have ‘draft tube wall to accommodate the flow.
(3. In a hydraulic turbine installation the
certain advantages in particular installa
tions, for example, the arrangement of Fig combination with a turbine runner, of a draft
ures 8, 9 and 10 is preferable to the others tube for the flow from said runner comprising
5
1,722,438
a circular wall ?aring outward at its lower a portion lying nearer to the axis than the
end into a substantially horizontal direction outlet of said draft tube, said collecting pas
and a separate collection chamber on each sage being adapted to receive the flow from
side of said wall for the ?ow from said draft said outlet at a considerable velocity and to
tube, said collection chambers being oppo cause said flow to be gradually decelerated. 70
sitely directed and extending around said
12. In a- turbine a radially spreading draft
wall and overhanging the edges of said wall, tube discharging the flow outward away
the floor of said collection chambers being from the axis, and a collecting passage adapt
substantially horizontal. v
ed to receive the flow from said draft tube
10
7. In a hydraulic turbine installation the at a considerable velocity and to cause said 75
combination with a turbine runner, of a draft flow to be gradually decelerated, said col~
15
tube for the flow from said runner comprising
a circular wall flaring into a substantially
horizontal direction at its lower end, and a
separate collection chamber on each side of
said wall for the flow from said draft tube,
looting passage having a portion extending
radially inward around the outlet endof said
draft tube and forming a laterally project
ing and elongated lip, so that said‘ collecting
passage will have a portion lying nearer to
said collection chambers overhanging the the axis than the outlet of said draft tube.
edges of the draft tube wall and being sep
13. In a turbine a radially spreading draft
arated from each other by a central pier con tube discharging the flow outward away
tinuous with the draft tube wall on the down from the axis and a collecting passage re
stream side thereof.
ceiving the flow from the outlet of said draft
8. In a hydraulic turbine installation the tube, the outlet of said draft tube being part
85
combination with a turbine runner, of a draft ly formed as a depending projection extend
tube for the flow from said runner compris
25
ing inner and ‘outer circular walls forming
an annular draft tube flaring outwardly to
ward the horizontal and separate collection
chambers around said wall overhanging the
edgev of the outer wall of said draft tube and
separated from each other by a vertical wall
downstream from the draft tube wall and
forming a continuation thereof.
ing into said collecting passage,-and a pier
member extending in a downstream direc
90
tion from said projection and forming a
support for said projection from the wall
below.
‘
14. In a turbine aradially spreading draft,
tube-discharging the flow outward away 95
from the axis and a collecting passage on
each side receiving the flow from the outlet
9. In a turbine a radially spreading draft of said draft tube, the outlet of said d1aft
tube discharging the flow outward away from tube being partly formed as a depending
the axis, and a collecting passage receiving projection extending into said collecting pas
the flow from the outlet end of said draft sages and a pier member extending in a
40
100
tube which projects into said collecting pas
sage, the outer surface of said projection be
downstream direction from said projection ‘
ing formed so as to produce a laterally pro
from the wall below.
and forming a support for said projection
i
jecting lip whereby said collector passage
15. In a turbine aradially spreading draft
extends radially inward around only a por tube discharging the flow outward away
tion of said outlet, so that said collecting from the axis, a collecting passage formed
passage will have a portion lying nearer to as a double spiral surrounding the outlet of
the axis than the outlet of said draft tube.
said draft tube, the outlet end of said tube
10. In a turbine a radially spreading being partly formed by a projection extend~
draft tube, discharging the flow outward ing from the wall of said collecting passage
away from the axis, and a collecting passage and having a generally elliptical form in sec
tion extending in a downstream direction,
let end of said draft tube which projects into and a central tapered pier supporting said
said collecting passage, the outer surface of extension from the opposite wall.
said projection being formed so as to pro
16. In a'turbine a draft conduit compris-j
vide laterally projecting lips whereby said ing an axial discharge passage ?aring out
collector passage extends radially .inward on ward at its end as a radially directed annu
each side of said outlet and only around a lar passage having itsdownstream portion
portion thereof, so that, said collecting pa; extended further than the lateral side. por
sages have portions lying nearer to the axis tions so as to terminate in a non-circular
than the outlet of said draft tube.
opening discharging the flow into a sur
11. In a turbine a radially spreading draft rounding discharge passage.
7
tube discharging the flow outward away
17 . In a turbine a draft conduit compris~
from the axis, and a collecting passage re~ ing an axial discharge passage ?aring out
ceiviug the flow from the outlet end of said ward at its end as a radially directed annu~
105
110
on each side receiving the flow from the out
55
60
draft tube and having a portion extending lar passage having its downstreamvportion
radially inward around said outlet end and extended further than the lateral side por
forming a. laterally projecting and elongated
tions so as to terminate in a non-circular
lip, so that said collecting passage will have opening discharging the flow into a surround
115
120
125
6
1,722,438
ing discharge passage and a discharge pas
sage receiving the iiow from the outlet of
said draft tube and having a portion extend~
ing radially inward around said outlet end
and forming a laterally projecting lip so
gradually reduced thickness as it extends
away from the axisof the inlet section.
25. A draft tube for water turbines having
inlet and outlet sections at an angle to each
of said draft tube.‘
18. In a turbine a radially spreading draft
tube discharging the flow outward away
from the axis and having an elongated por
tion extending downstream, and a collecting
chamber receiving the flow from the outlet
end of said draft tube and having a portion
extending wall projection with substantially
65
other, the outlet section having relatively
that said collecting passage will have a por deep side portions and a relatively narrow
tion lying nearer to the axis than the outlet middle portion formed by a longitudinally
10
vertical side surfaces.
26. A draft- tube for water turbines having
a delivery section with an inlet formed by
a. ?ared top wall port-ion the forward part of
which is continued forwardly to form a lon~
gitudinal roof extension tapered away from
extending upward around said outlet end the side walls of the section as the free end
and radially inward to form a lateral pro~ is approached and having substantially ver—
jecting lip so that said collecting chamber tical side surfaces.
SO
27. A draft tube for water turbines having
will occupy space above said outlet and‘ ly
inlet and outlet sections at an angle to each
ing nearer to the axis than said outlet.
19. In a turbine a straight draft tube other, the outlet- sections having relatively
having an outwardly ?aring end spreading deep side portions and a relatively narrow 85
the flow laterally and an elongated down middle portion formed by a longitudinally‘
stream portion for conducting flow in a extending wall projection with substantially
30
downstream direction and a collecting cham vertical side surfaces, the side portions curv
ber receiving the flow from the outlet of said ing inwardly as they approach the upstream
draft tube and extending radially inward end of the outlet section.
28. A draft tube for water-turbines having
from said outlet and forming a lateral pro
jecting lip, so that said collecting chamber inlet and outlet sections at an angle to each
.will have a portion lying nearer to the axis other, the outlet section having relatively
deep side portions and a relatively nar
than the outlet of said draft tube.
20. A draft tube for water turbines having row middle portion formed by a longitudi
90
95
inlet and outlet sections at an angle to each nally extending wall projection with sub
other, the outlet section having a flat ?oor stantially vertical side surfaces, the side por
surface and an upstream wall and relatively tions having a varying depth.
deep side portions of gradually decreasing 29, A draft tube for water turbines having
depth toward the upstream wall said- side inlet and outlet sections at an angle to each
100
portions being entirely above the level of the other, the outlet section having relatively
4-0
floor surface of the outlet section.
deep side portions and a relatively narrow
other, the outlet section having a roof sur
side portions gradually decreasing toward
21. A draft tube for water turbines having middle portion formed by a longitudinally
inlet and outlet sections at an angle to each extending wall projection, the depth of the.
face and a longitudinally disposed project— the upstream end of the outlet section and a
ing roof portion with substantially vertical central longitudinal pier member support
45
side surfaces extending downward from said ing said projection from the floor of said out
let section.
roof surface.
22. A draft tube for water turbines having" 30. A draft tube for water turbines having
110
inlet and outlet sections at an angle to each inlet and outlet sections at an angle to each
50
other, the outlet section having a projecting other, the outlet section having relatively
roof portion extending toward the free end deep side portions and a relatively narrow
of the section and a central longitudinal pier middle portion formed by a longitudinally
member supporting said-roof portion from extending wall projection, the side portions
curving inwardly and their depth gradually
the floor of said outlet section.
23. A draft tube for water turbines having
inlet and outlet sections at an angle to each
other, the outlet section having a roof sur
face and between the sides thereof a longi
60
115
decreasing toward the upstream end of the
outlet section and a central longitudinal pier
member supporting said projection from the
tudinally disposed tapered projecting por
?oor of said outlet section.
31. A draft tube for water turbines having
inlet and outlet sections at an angle to each
side portions of gradually decreasing depth
tion with substantially vertical side surfaces inlet and outlet sections at an angle to each
extending downward from said roof surface._ other, the outlet section having a flat ?oor
24. A draft tube for water turbines having surface, an‘ upstream wall and relatively deep
other, the outlet sectionhaving between the toward the upstream wall both entirely above
sides thereof a projecting portion with sub-7 the level of said ?oor surface, said inlet-sec
stantially vertical side surfaces and being of ~ tion having 'a bell shape lower end, and a
120
1,722,438
cone projecting upwardly into said inlet sec
7
portions being disposed entirely above the
tion to form an annular passage with respect level of said floor surface and the lower end of
said inlet section being ?ared outwardly to
to said bell.
32. A draft tube for water turbines having form a bell while said upstream wall termi
inlet and outlet sections at an angle to each nates adjacent said bell in substantially a
other, the outlet section having a flat ?oor wedge shape formation.
38. A draft tube for water turbines hav~
surface, an upstream wall and relatively deep
10
side portions of gradually decreasing depth ing inlet vand outlet sectionsat an ‘angle to
toward the upstream wall, both of said side each’ other, the outlet section having a fiat
portions being disposed entirely above the floor surface, an upstream wall and relatively
75
level of said ?oor surface while said inlet deep side port-ions of gradually decreasing
section has a bell shape lower end, and a cone depth toward the upstream wall, both of said
projecting upwardly into said inlet section side portions being disposed entirely above
'for only part of the length thereof to form the level of said floor surface and the lower
15 an annular passage with respect to said bell. end of said inlet section being flared outward~ 90
33. A draft tube for water turbines having ly to form a bell while said upstream wall tier-y
inlet and outlet sections at an angle to each minates adjacent said bell in substantially a
other, the outlet section having a flat floor wedge shape formatlon, whereby there is
surface and an upstream wall and relatively formed a spiral wall starting at the wedge
20 deep side portions of gradually decreasing and continuing outwardly in a downstream
depth toward the upstream wall, and en direction.
39. The combination in a draft tube com
tirely above the level of said floor surface
while said inlet section has a bell shape lower prising an inlet section of substantial length,
end, and a cone projecting upwardly into a collector passage provided with a roof
said inlet section to form an annular passage which in transverse sectionhas portions dis
with respect to said bell, said inlet section posed at different elevations, said inlet sec—
having a relatively long substantially tion having an outlet projecting below one
straight conical section which merges with of said roof portions and being turned down
the bell portion.
' stream into said collector passage to form the
30
34. A draft tube for water turbines having other of said roof portions.
inlet and outlet sections at an angle to each
95
40. The combination in a draft tube com
other, the outlet section having between the prising a relatively gradually flaring inlet
sides thereof a projecting portion with sub~ section of substantial length, a collector pas
stantially vertical side surfaces and being of sage provided with a roof which in trans
gradually reduced thickness as it extends verse section has portions disposed at dif
away from the axis of the inlet section, said ferent elevations, said inlet section having
inlet section having its lower end flared out an outlet projecting below one of said roof
wardly to form a bell, and a cone disposed portions and being turned downstream into
100
centrally therein to form an annular passage said collector passage to form the other of
said roof portions, the roof portion at the
leading to said outlet section.
35. A draft tube for water turbines having center of said passage being at a lower ele
a delivery section with an inlet formed by a vation than portions of the roof laterally
?ared top wall portion the forward part of spaced from said central portion.
which is continued forwardly to form a lon
105
41. The combination in a draft tube, com
gitudinal roof extension tapered away from prising an inlet section and horizontal dis—
110
the side walls of the section as the free end charge passage provided with a roof which
is approached, and having substantially ver in transverse section has portions disposed at
tical side surfaces, a central core disposed different elevations, said inlet section having
a portion projecting below one of said roof
within at least a part of said inlet section.
36. A draft tube for water turbines having portions and being turned and elongated
inlet and outlet sections at an angle to each downstream into said discharge passage.
42. The combination in a draft tube, com
other, the outlet section having a flat floor
surface, an upstream wall and relatively deep prising an inlet section and horizontal dis
side portions of gradually decreasing depth charge passage provided’ with a roof which
115
toward the upstream wall, both of said side in transverse section has portions disposed at
portions being disposed entirely above the different elevations, said inlet section having
(30
65
level of said floor surface while said upstream a portion projecting below one of said roof
wall terminates substantially adjacent the portions and being turned and elongated
downstream into said discharge passage,said
lower end of said inlet section.
37. A draft tube for water turbines having downstream elongation being disposed cen
inlet and outlet sections at an angle to each trally of said discharge passage whereby the
other, the outlet section having a ?at floor discharge passage has two relatively deep
surface, an upstream wall and relatively deep side passages disposed substantially entirely
side portions of gradually decreasing depth above the floor of said discharge passage.
toward the upstream wall, both of said side
43, The combination set forth in claim 41
130
8
1,722,438
45. A draft tube for Water turbines hav
ing inlet and outlet sections at an angle to
each other, the outlet section having a ?oor
stream end thereof.
44:. A draft tube for Water turbines having surface at least a portion of Which is sub
further characterized in that said down
stream elongation tapers toward the down
inlet and outlet sections at an
to each stantially straight in a downstream direction,
other, the outlet section having a iioor sur
face at least a portion of Which is substan
and also having relatively deep side portions
of gradually decreasing depth towards the
tially straight in a downstream direction, and upstream end of said outlet section, said side
10
also having relatively deep side portions of port-ions being substantially entirely above
gradually decreasing depth towards the up the level of the ?oor surface of the outlet sec
25
stream end of said outlet section7 said side tion, whereby there is provided a central elon
portions being substantially entirely above gated Wall portion extending in a doWn
15
the level of the ?oor surface of the outlet sec
stream direction, and said elongation being
tion, whereby there is provided a central elon
gated Wall portion extending in a down
thereof is approached.
stream direction.
tapered in transverse section as the free end' 30
LEWIS FERRY MOODY.