US1517916A

US1517916A - Slyyania

Info

Publication number: US1517916A
Authority: US
Publication date: 1924-12-02
Anticipated expiration: 1941-12-02

Description

L. F. MOODY nynnmmc TURBINE Filed March 23.- 1917 a Sheets-Sheet 1 In Lu. v 3 3.

INVENTOR L. F. MOODY HYDRAULIC TURBINE Filed March 25. 1917- 6 Sheets-Sheet 2 INVENTOR ATTORNEYS 1,517,916 L. F; MOODY' HYDRAULIC TURBINE Filed March 25.1917 6 Sheets-Sheet s ATTORN EYS Dec, 2, 1924. 1,517,916

L. F. MOODY HYDRAULIC TURBINE Filed March 23, 1917 6 Sheets-Sheet 4 ATTOR NEYS L. F; MOODY HYDRAULIC TURBINE Filed March 25. 1917 6 Sheets-Sheet 5 W M M llli INVENTOR ATTORNEYS 6 Sheets-Sheet 6 L. F. MOODY HYDRAULIC TURBINE Filed March 23. 1917 "UHF.

QENVENTOR ATTORNEYS Patented Dec. 2, 1924.

UNITED STATES PATENT OFFICE.

LEWIS I. MOGDY, OF PHILADELPHIA, PENNSYLVANIA, ASSIGN'O'Ri TO WILLIAM CRAMP '.& SONS SHIP 8c ENGINE BUILDING COMPANY, A CORPORATION OF PENN- I SLYVANIA.

HYDRAULIC TURBINE.

hppllication filed March 23, 1917. Serial No. 156,813.

TOCZZ'Z wlz-om'z't may concern:

Be it known that I, Lnwrs F. MoonY, a citizen of the United States, residing in the city and county of Philadelphia, State of Pennsylvania, have invented a new and useful Hydraulic Turbine, of which the following is a'specification.

In "the design of hydraulic power developments, particularly those utilizing low heads produced by 'darnming streams, a problem of great importance is that of maintaining the output of the station during times of freshet. Although the energy available in thestream at such times is much larger than under ordinary conditions of flow, the head in nearly all low head plants is seriously impaired, due to the excessive quantity of water flowing. It therefore follows that when "the maximum amount of energy is available in the stream, "the capacity of the power (P1211113 is at a minimum. The unutilized enengy is wasted over spillways and dissipated in turbulence below the dam. The problem at such times is: to provide sufficient spillways, sluice gates or passages to care for the flood flow and to prevent the energy of the water being expended in destroying the structures of the dam and station.

In the great majority of water power developments, it is very important to utilize the normal flow of the stream with the best obtainable efficiency, and since this normal flow takes place during the major portion of the year, it is not desirable to employ a device for utilizing the surplus flow which will necessitate any change in the normal design of the turbine, which would impair its efficiency at times when the surplus flow apparatus is not in use, that is, under the usual conditions of operation.

It has heretofore been proposed to employ three different methods for the purpose of utilizing a portion of the excess flow.

Under one method, extra turbines and generators are installed with a corresponding increase in the size of the power house and sub-structure. By such method, the station and machinery must in some cases be extended to several times the capacity required for normal operation with a correbut avoids the expense of extensions to the power house and the installation of additional generators. The most serious objections to this second method are the mechanical complexities of the turbine and the reduction of the efficiency of the turbine during normal operation. This is a serious objection, since in order to provide power during a few days in the year, it is necessary with such arrangement to impair the efiiciency of the turbine during the rest of the year and when the water is low.

Under a third method, some form of ejector is installed on each turbine to utilize a portion of the excess flow for the purpose of decreasing the discharge pressure acting against the turbine. Since the effect of the flood flow in most of the developments of this kind is to raise the tail water a large amount without a corresponding rise in the head water, it becomes feasible to reduce the pressure at any point in the draft tube without decreasing this pressure below the minimum allowable value corresponding to bar ometric conditions. The effect will be to restore approximately the normal effective head on the turbine.

In all the methods heretofore proposed for utilizing an ejector, certain drawbacks have been present which seriously affect the economy of the application.

The operation of the ejector depends on the following actions:

First. By injecting water from the forebay or casing into the draft tube, there is produced a continuous force or impulse which is exerted against the water filling the portion of the draft tube below or beyond the ejector, which tends to push this water out of the draft tube and to leave a reduced pressure behind it at the point where the injection water enters. For this force and consequent pressure reduction to be a maximum, the mass and velocity of the injection water should be as large as possible, and the direction at which it enters should be inclined at the smallest possible angle to the axis of the draft tube.

Second. By increasing the quantity of water flowing in the draft tube by the addition of the injection water and by the pro vision of a. long diffuser or gradually diverging tube beyond the injection point, a high velocity is created in the tube. The velocity head is reconverted into pressure head in the diverging portion of the tube. This conversion of velocity head into pressure head is effective for reducing the static pressure at the point of high velocity. In order to utilize this action, the losses of head due to friction, eddies and impact must be reduced to a minimum. The chief losses are the impact losses where the rapidly moving injection water mixes with the more slowly moving water coming from the turbine runner, the losses occurring in the expanding tube or diffuser and the loss of residual velocity head at the final discharge.

The impact loss can be reduced by making the difference between the two velocities as small as possible.

The expansion losses can be kept low by providing a sufficiently gradual divergence in the diffuser. The loss of residual velocity head can be limited by providing suflicient length and discharge area of the tube.

Vith the foregoing in view, my present invention consists of a novel hydraulic turbine, wherein the injection water is introduced at the point of lowest pressure in the draft tube and at the point of maximum available velocity in the draft tube, thereby securing a maximum velocity for the injection Water and minimizing the impact losses. This point of lowest pressure and of maximum available velocity is immediately below the runner.

In order to reduce the losses due to expansion and final discharge, I employ the longest possible diverging tube and use as large a portion of the draft tube as possible for the flow of the injection water after mixing with the runner discharge. By introducing the injection water as near as possible to the entrance end, that is near the runner, or as near to the runner as is consistent with a small angle of inclination of the injection velocity to the axis of the draft tube, I avoid the necessity of greatly extending the draft tube beyond the di1nensions required for normal operation.

A further purpose of my invention is to devise a hydraulic turbine in which it is not necessary to modify the draft tube from the form required for high efficiency of the turbine during normal. operation, at which time the ejector is closed and out of operation.

A further purpose of my invention is to devise a hydraulic turbine with an ejector which does not require large additional structures or extensions to the power house, and one wherein the ejector is built preferably as an integral part of the turbine, for convenience in manufacture, installation and operation, and one wherein it is supplied with water taken from the turbine casing without requiring the construction of separate supply passages. The additional conduit area needed in separate passages can be more easily supplied by enlarging the turbine intake and easing a moderate amount and such additional area can be utilized to advantage by the turbine during normal operation.

A further purpose of my invention is to devise a novel construction of curved ribs or vanes for the purpose of receiving the water at the proper angle from the volute or other casing and directing it diagonally into the draft tube so that it will possess an amount of whirl suited to the whirl with which the turbine discharge leaves the runner. The whirling velocity of the water in the turbine casing can be utilized to produce thg desired whirling velocity in the draft tu e.

A further purpose of my invention is to devise a novel turbine in which the curved ribs or vanes of the ejector can be placed immediately below the vanes of the turbine speed ring, thus affording iirm support for the unit. The ejector takes the place of the inner wall of the turbine casing, thereby displacing a certain amount of concrete and simplifying somewhat the form work of the casing. The movable gate of the ejector is preferably constructed in such a manner that it can be withdrawn through the turbine speed ring and pit liner which are set rigidly in the concrete, thereby rendering easy the dismantling and replacement of the movable parts of the ejector.

Other novel features of construction and advantage will hereinafter more clearly ap pear in the detailed description of my in vention.

F or the purpose of illustrating my invention, I have shown in the accompanying drawings, typical embodiments of it, which are at present preferred by me, since these embodiments will give in practice satisfactory and reliable results, although it is to be understood that the various instrumentalities of which my invention consists can be variously arranged and organized and that my invention is not limited to the precise arrangement and organization of these instrumentalities as herein shown and described.

Figure 1 represents a sectional elevation of a hydraulic turbine embodying my invention.

Figure 2 represents a sectional plan view,

the section "being taken on line 22 of Figure 1.

Figure 3 represents a sectional elevation,

showing the same type of ejector, as seen in the section being taken on line 66 of Figure 7.

Figure 7 represents a sectional elevation of a turbine having a register type of gate.

Figure 8 represents a section on line S8 of Figure 9.

Figure 9 represents a sectional elevation of another embodiment of my invention, showing a different manner of operating the gate.

Similar numerals of reference corresponding parts in the figures.

Referring to the drawings In the accompanying drawings, I have illustrated the mechanical arrangement of the indicate ejector in conjunction with a turbine of the vertical shaft single runner type, it being understood that my invention is not limited to any particular type of turbine. I have deemed it unnecessary to illustrate in full detail the complete construction, it being understood, for example, that all moving contact surfaces would preferably be provided with bushings or liners of any desired material.

Referring first to Figures 1 and 2, 1 designates the turbine speed ring which is set rigidly in the

concrete

2, 3 designates the guide vanes or turbine gates, and 4: designates the runner or the turbine wheel.

5 designates the draft tube which extends from the turbine runner to the final point of discharge into the tailwater, as at 6. This draft tube gradually increases in diameter the weight of the turbine, the generator,

and part of the weight of the power house structure, this load being transmitted through the speed ring 1, it being seen that the ejector casing is set in'and carried by the concrete foundation. The vanes 9 are curved in the horizontal'planefto suit the direction of the water entering from the volui'e casing 10, see Figure 2, and to discharge the injection water into the draft tube with a whirl component of velocity about the turbine axis to suit the direction of the water discharged from the runner. In place of these curved vanes, stay bolts could be used, the water being permitted to follow its natural spiral path. The ejector vanes arepreferably located in'imediately below each speed ring vane, in order to carry the weight transmitted by the speed ring vanes in direct vertical lines, the corresponding vanes forming parts of a continuous column.

11 designates a stationary ring, the inner surface of which forms a part-of the draft tube Guided between this ring 11 and the auxiliary casing 7 is a gate 12 of ring formation, the lower end of which is beveled or inclined, as indicated at 18, so that it merges with the curvature of the wall of the passage 8. This gate 12 can be operated in any desired manner and, as shown, is provided with the brackets 14; to which are connected the rods 15, which are connected by means of links 16 to the bell-crank lever 17 secured to the rock-shaft 18, said bell-crank levers being operatively connected to a piston rod 19 of a motor 20 of any desired or conventional type, such as for example, an

electric or hydraulic motor. As illustrated, 20 is a hydraulic cylinder and piston operated by water or oil pressure.

The dotted lines in Figure 1 show the gate in closed position, from which it will be understood that when the ejector gate is closed, the draft tube will retain its proper form consistent with high eiiiciency of the turbine.

The irregularities in wall contour remaining when the gate is closed are merely such as are required by a proper thickness of metal in the piece 11, which may be made so small as to have no measurable effect on the turbine performance.

The details of construction are more clearly shown in Figure 5, which is drawn to a larger scale. In this figure, a typical turbing the speed ring or the stationary portions of the ejector is illustrated. By unbolting them from the piece 21, the curb plate or lower distributor plate 22, and the upper section 11 of the draft tube 5, may be withdrawn through the speed ring and the turbine pit, after which the brackets Lt connected with the gate can be disconnected, and the piece 21, which is in sections, can be removed. The gate can then be removed upwards through the speed ring. It will be apparent from the drawings that I preferably employ a concrete foundation and that the draft tube is molded in the concrete.

In the construction shown in Figure 3, the ejector is of the same type as that already method of removing the gate 12 without disdescribed, but it is shown as applied to a turbine having a straight draft tube :23, which is constructed of metal, as illustrated, or of other desired material. The remaining portions of the turbine and ejector are similar in construction to that already described and a further detailed description thereof would involve needless repetition.

Referring now to the embodiment seen in Figures 6 and 7, I have illustrated in said figures my invention as utilizing a register type of gate. This arrangement of ejector can of course be used interchangeably with the cylinder type in connection with any of the shapes of draft tubes shown in other figures of the drawings.

In this embodiment, E4 designates a speed ring. 25 designates the guide vanes or turbine gates, and 26 designates the runner. 27 designates a draft tube. 28 designates the injector casing, which is provided with the curved vanes 29 forming the passages 30. 31 designates a register gate which is provided with ports 32 which are adapted to register with the passages 30. This re, ;is ter gate 31 consists of an annulus having at its upper end an annular flange 3?) which is rotatably mounted on a shoulder 34: formed on the ejector 28. The upper portion of the draft tube 27, above the gate 31 consists of an annulus which is mounted on a sectional ring 35, so that by removing

such parts

27 and 35 and the parts above the register gate, the register gate is free to be removed through the speed ringand the turbine pit, for the purpose of dismantling or repairs. The register gate 31 is closed by moving in a rotary direction through a distance equal to the width of each of the openings in the draft tube, which as illustrated are rectangular in contour, and when closed, the gate will leave the draft tube walls in proper form for the best efficiency of the turbine.

The gate has connected thereto in any de sired manner the rods 36 which are connected to a bell-crank 37, said bell-cr: ml ,being connected to an operating shaft 38. The operating shaft is rotated through the required angle by means of a hydraulic cylinder 39, which is connected by links 40 to an arm or lever 41, which in turn is keyed to the top of the operating shaft. Other means for moving the gates, such as an electric motor and suitable mechanism, may be used in place of the cylinder 39.

Referring now to the embodin'ient shown in Figures 8 and 9, I have illustrated in these figures an alternative method of operating the cylinder gate. In this embodiment, the actuating rods l2 are connected by brackets 43 to the cylinder gate 44, as in Figures 1 and 5. The actuating rods l2 have their upper ends threaded, as at d5, to receive nuts 46 which form worm gears registering with the worms 47 on the shafts 48, 4-9 and 50, said

shafts

48 and 49 being intergeared with the shaft 50, and the shaft 50 being driven by an electric or other motor 51.

In Figure 4, l have illustrated my novel ejector as applied to a spiral form of draft tube 52, such as disclosed in my copending application, Serial No. 91,037, filed April 14th, 1916, and while in this figure, I have illustrated the cylinder type of gate 55, it will be understood that the register type of gate, seen in other figures of the drzuvings, is equally applicable to a spiral form of draft tube, or to a straight draft tube such as is shown in connection with a cylinder gate in Figure 3. This draft tube has an inner central conical core 53 and an outer wall 57, both the inner core and outer wall being formed as surfaces of revolution around. the runner axis. Both the inner and outer surfaces flare outwardly from an axial direction toward a radial direction so that they form between them an annular passage receiving the discharge from. the runner and turning it out-ward on all sides while permitting it to rotate around in natural spiral lines of flow. The side wall connecting the core 53 and outer wall 57 extends around in generally spiral formation. following the natural direction of the lines of flow.

In connection with a spiral draft tube, an ejector will have particular value owing to the ability of such a draft tube to regain the energy of a whirling discharge from the runner or auxiliary passages. A draft tube, which is capable of regaining a considerable portion of the kinetic energy of the whirl.- ing or tangential components of velocity of the water entering the draft tube, permits the turbine runner to be economically operated under conditions involving a diagonal direction of discharge from the runner and a resulting rotational or whirling flow in the water entering the draft tube. Turbines in which the runner discharge contains a considerable amount of whirling velocity are particularly suited to low-head power developments for which the ejector draft tube is most frequently applicable. From the principles heretofore explained, it will be understood that if the draft tube is designed to convert velocity head of whirl of the water leaving the runner into useful pressure head and if such action forms an essential part of the function of the draft tube, then in order to obtain the most effective results from the injection of auxiliary water for ejector purposes, this auxiliary water must also be injected in a direction having considerable rotational or whirl component in order to utilize most fully the ability of the draft tube to convert velocity head into pressure head.

The water in passing through a flaring draft tube in spiral paths causes a centrifugal action involving an increase in pressure from the inlet end of the draft tube towards the discharge end of such draft tube and thereby decreases the pressure at the inlet of the draft tube and thus causes an increased flow of water through the turbine runner. If the water is admitted into the draft tube in a whirling direction, it will continue to travel throughout a flaring draft tube in a whirling direction and produces in such flaring tube a centrifugal force of the rotating mass of water which is effective in reducing the pressure at the inlet end of the tube.

From the foregoing it will be understood that the auxiliary water enters the draft tube in a direction having a large component parallel to the draft tube axis and also a tangential or circun'iferential component with respect to the draft tube axis. The whirl already existing in the turbine casing when a volute casing is used on the turbine can be utilized to increase the whirl in the spiral draft tube simply by by-passing' the flow from the casing to the draft tube, either with or without the help of directing vanes in the injector casing.

In my present invention, the water discharged from the turbine runner is maintained at nearly its full velocity to the point where the surplus water is admitted and no subsequent contraction of the draft tube is permitted. The draft tube continuously in" crease-sin cross sectional area in a manner best suited to the highest efficiency of the turbine under normal operating conditions, while at the same time, when the gate is opened, the ejector will produce the maximum effect immediately adjacent to the runner.

I have shown and described different cm bodinients of ejector and difi'erent types of gate together with several methods of operating the gate. It is not, however, my intention to limit the invention to the embodiments shown and described; for instance, gates of the movable guide vane or wicket type could be used similar to those shown at 3, at entrance to the runner in Figure 1, or 25 in Figure 7, and the operating mechanism could utilize sprocket chains, combinations of levers and rods, or other devices than those shown.

I have used the term ejector to signify the combination of the injector casing containing auxiliary passages, the regulating gate and the turbine draft tube.

It will now be apparent that I have devised a novel and useful hydraulic turbine which embodies the features of ad'x' antage enumerated as desirable in the statement of the invention and the above description, and while I have, in the presentinstance, shown and described typical embodiments thereof which will give in practice satisfactory and reliable results, it is to be understood that these embodiments are susceptible of modification in various particulars without departing from the spirit or scope of the invention or sacrificing any of its advantages.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent, is

1. In a hydraulic turbine, a d aft tube having in proximity to its inlet end controllable apertures in d rect communication with the turbine casing, the draft tube when said apertures are closed continuously increasing in cross-sectional area from its inlet to its outlet, to effect a gradual and continuous reduction in velocity from the runner to the tail race.

2. A turbine having, as a part of its support, a casing provided with apertures to by-pass the water into the draft tube immediately beneath the runner,turbine gates, and means independent of said gates to control sad apertures.

3. A turbine having a draft tube, the in- .letportion of which contains apertures and means to close them, said draft tube when the apertures are closed continuously increasing in cross-sectional area from its inlet to its outlet to gradually decrease the velocity of the water during its passage from the runner to the tail race.

4-. A hydraulic turbine having a speed ring, a draft tube, and an ejector casing discharging into said draft tube and containing vanes forming in connection with the vanes of said speed ring substantially vertical columns.

5. A hydraulic turbine having a speed ring, auxiliary passages beneath said speed ring, and a gate controlling said passages and withdra vable through said speed ring.

(5. A hydraulic turbine having a speed ring, a draft tube, an ejector casing supporting said speed ring, and a gate for sa d casing, the inner surfaces of said casing and gate when the latter is closed being in alignment with and'forming a part of the inner surface of said draft tube.

7. A hydraulic turbine having a foundation, a speed ring, an ejector casing interposed between said foundation and speed ring and supporting said speed ring, and a gate, removable through said speed ring.

8. A hydraulic turbine having a draft tube, a speed ring, flow control means within said speed ring, an auxiliary casing supporting said speed rug and containing apertures, the upper walls of which are shaped to inject the water obliquely .into said draft tube, a gate controlling said apertures, and means to actuate said gate.

9. A hydraulic turbine having an admiss on space, a urbine runner, a draft tube, said turbine being provided with one or more passages and forming when closed a part of the draft tube, the latter continu-- ously enlarging in area from said runner to its discharge end.

10. A hydraulic turbine having an intake space, a draft tube, one or more passages.

connectin them and a re ulatin gate con- 2 7 Ln trolling said one or more passages and causing, when closed, said draft tube to increase gradually and continuously in cross section from its entrance end to the discharge into tailwater.

11. A hydraulic turbine having a speed ring with vanes, a runner, flow control means Within said speed ring a superstructure, and a draft tube, in combination with an auxiliary casing supporting said speed ring and superstructure and having passages communicating with said draft tube.

' 12. A hydraulic turbine having a speed ring, a superstructure thereon, a runner, and a'draft tube receiving the discharge from said runner, in combination with an auxiliary casing supporting said speed ring and superstructure and having passages communicating with said draft tube, and a gate controlling said passages, said gate, when closed, forming a part of the draft tube, and so formed that the draft tube gradually increases in cross section from its entrance end towards its discharge end.

13. A turbine having a volute casing provided with one or more passages extending from said casing to the draft tube in proximity to the runner, said passage or passages being provided with vanes or ribs connecting thetwo sides thereof and shaped to conform to the direction of the water entering from the volute casing.

14. A hydraulic turbine having a turbine casing, a runner, passages admitting water thereto, and a draft tube, and provided with one or more auxiliary passages separate from those admitting water to the runner, said auxiliary passages leading directly from the turbine casing to said draft tube, and. a regulating gate for controlling said one or more passages, said draft tube, when the gate is closed, continuously enlarging in area from the runner to the discharge end to gradually decrease the velocity ofthe water during its passage from the runner to the tailrace.

15. In a turbine the con'ibination with a runner discharging the water along generally spiral. lines of flow and a draft tube receiving said discharge, of one or more by pass passages leading from the intake to said draft tube and formed to. permit the flow in the bypass to partake of the natural spiral lines of flow of the discharge.

16. In a turbine the combination with a runner discharging the water along generally spiral lines of flow and a draft tube adapted to smoothly pass and decelerat-e said discharge along said spiral lines of flow, of one or more bypass passages leading from the intake to said draft tube and formed to permit the How in the bypass to partake of the natural spiral lines of flow of the discharge.

17. A hydraulic turbine having one or more auxiliary orifices or passages leading from the intake to the draft tube and formed by ribs or vanes constructed to direct water into the draft tube in an oblique direction both with respect to the turbine axis and to a plane containing the turbine axis.

18. A hydraulic turbine having one or more auxiliary passages leading from the turbine casing or intake to the draft tube and formed to direct the water entering the draft tube in a direction having a large com ponent parallel to the draft tube axis and also a tangential or circumferential co1nponcut with respect to the draft tube axis.

ii). in a hydraulic turbine, the combination with a casing, a runner, and a flaring draft tube, of means to bypass the water into the draft tube immediately beneath the runner, so that the bypassed water. stream will come into immediate contact with the high velocity stream discharged from the runner, the stream then being gradually and continuously reduced in velocity by said flaring draft tube.

20. A hydraulic turbine having a draft tube, the ininiu'uun cross section of which is at the 'runner end and having one or more oritices or passages arranged to divert water from the turbine :asing into the draft tube without passing it through the runner, said oritices or passages opening into the draft tube in close proximity to its point of least cross sectional area.

21. A hydraulic turbine having a spiral draft tube provided with one or more orifices or passages interconnecting the casing and draft tube, said passages being formed by vanes shaped to direct the ater into the draft tube in a direction having atangential component with respect to the turbine axis.

22. A hydraulic turbine having a turbine pit, a turbine speed ring, an ejector casing, and a draft tube, and provided with one or more orifices or passages leading through said casing directly into the draft tube, and a gate controlling said orifices or passages and arranged to be withdrawn in a direction coinciding with the turbine axis by passing it tl'irough the speed ring and turbine pit.

23. A hydraulic turbine having a foundation, a speed ring, a superstructure, a draft spiral or more the casing and draft tube.

Ihe combination with a spiral draft tube, of an ejector discharging thereinto.

26. The combination of a volute casing, a drafttube, and means to pass aimiliary Water from said casing directly to said draft tube in spiral paths.

527. In a turbine, a draft tube, a runner, means to pass water therethrough, and means to introduce auxiliary water into said draft tube in spiral paths Without passing it through said runner.

28. In a hydraulic turbine, a draft tube, and an ejector having in common. with said draft tube a spiral discharge passage.

29. A hydraulic turbine having a con-- crete foundation, a draft tube molded therein, and an ejector casing supported on said concrete foundation at the inlet end of said draft tube and forming a continuation thereof;

30. A hydraulic turbine havingaconcrete foundation, a draft tube molded therein, and a metal ejector casing supported on said foundation, the inner surface of said casing forming a continuation of said draft tube.

31. A hydraulic turbine having a concrete foundation, a draft tube molded therein, an ejector casing supported on said concrete foundation, the inner surface of said casing forming a continuation of said draft tube, and a speed ring carried by said ejector casing.

A hydraulic turbine having a foundation, a draft tube, an ejector casing on said foundation and forming a continuation of said draft tube, a speed ring resting on said casing, a turbine runner, said casing having means to bypass Water into the draft tube directly beneath the runner Without such Water passing through the runner, and a gate controlling said means and movable into said casing directly beneath said speed ring When the gate is in open position.

33. In a hyraulic turbine, a speed ring, and an ejector casing serving as a support for the speed ring, forming a continuation of the draft tube at the inlet end of the latter, and having means to bypass Water into it at substantially its point of least internal diameter.

34. In a hydraulic turbine, a draft tube, a runner discharging Water into said draft tube in directions having tangential components with respect to the turbine axis, and means to pass auxiliary Water into said draft tube in directions having tangential components with respect to the turbine axis, said auxiliary water not being passed through the runner.

35. The combination of a draft tube constructed to convert kinetic energy of tangential components of the velocity of flow into pressure energy, and means to inject into said draft tube auxiliary flow in a direction having a tangential componem; With respect to the turbine axis.

36. The con'ibination of a draft tube formed. to convert into presure head a por tion of the kinetic energy of Water ei'itering the tube with tangential components of motion about the draft tubeaxis, and means for admitting auxiliary water into said draft tube in directions having tangential components With respect to said axis.

37. A hydraulic turbine having an atmission space, a runner, and a flaring draft tube, said tijnrbine being provided with one or more passages located in close proximity to the runner and directly connecting said admission s} ace with said flaring draft tube, and a regulating gate for controlling said one or more passages and forming when closed a continuation of the draft tube Walls.

38. A draft tube adapted for the flow of Water theretl'irough in spiral paths diverging from the axis between an inner central conical core and an outer Wall, surounding said core and an ejector discharging into said draft tube.

39. A draft tube having an outer flaring Wall and an inner conical core Within said Wall forming between them a passage for the flow surroluiding said core, and an ejector discharging into said draft tube.

4-0. A draft tube having Walls which are surfaces of revolution flaring in a direction approximately normal to the axis, and means to inject into said draft tube auxiliary Water having a tangential velocity component With respect to said axis.

41. Aturbine having a runner, means for admitting a motive fluid to the runner, and a single draft tube having a ring associated with one end thereof, said ring having passages opening into the draft tube to in crease the suction in the said tube and the head of the motive fluid on the runner, the passages of the ring being divided at intervals by partition means.

42. A turbine having a runner, means for admitting a motive fluid to the runner, and a single draft tube having a supplemental fluid inlet ring fixed to one end thereof and transversely partitioned at intervals to form passages opening into the tube for the inlet of a supplemental volume of Water and egcrating to increase the suction in the tube and the head of the motive fluid on the runner.

43. A turbine having a runner, means for admitting a motive fluid to the runner, a single draft tube, and a ring fixed to the draft tube and having an inlet passage therethrough disposed at an inward angle of inclination for admission of su1 plemental fluid into the tube bevond the runner to increase the suction in the said tube and the head of the motive fluid on the runner.

4:41. In a hydraulic turbine the combination with an intake and. a runner of a draft tube receiving the flow from the runner and continuously (:lecelerating it so as to convert its velocity head into effective pressure head, and a passage from the intake to the draft tube adapted to bypass a portion of the inflow into the draft tube, said draft tube being adapted to smoothly decelcrate and discharge said flow whether or not said flow has rotational components of velocity.

45. A. turbine having a runner and means for admitting water to said runner around its entire circumference. said turbine having as a part of its support a casing provided with apertures to bypass water into the draft tube immediately beneath the runner and having gates controlling the admission to said runner and means independent of said gates to control said apertures.

46. A turbine having, s a part of its support, a speed ring and a casing provided .with apertures to by-pass the water into the draft tube immediately beneath the runner, turbine gates within said speed ring, and means independent of said gates to control said apertures.

4:7. A. hydraulic turbine having a speed ring, a draft tube. and an ejector casing dis charging into said. draft tube and containing vanes forming in connection with the vanes of said speed ring substantially vertical columns and flow control means within the speed ring.

48. A hydraulic turbine having a foundation, a draft tube, an ejector casing on said foundation and forming a continuation of said draft tube, a speed ring resting on said casing, a turbine runner, flow control maans between said speed ring and said runner, said. casing having means to bypass water into the draft tube directly beneath the runner without such water passing through the runner, and a gate controlling said means and movable into said casing directly beneath said speed ring when the gate is in open position.

-19. A hydraulic turbine having a speed ring, a runner and a draft tube and flow control means within said speed ring, and an auxiliary casing supporting said speed ring and containing apertures to inject water into said draft tube, a gate controlling said apertures, and means independent of said flow control means to actuate said gate.

50. A turbine having an intake, a runner and a draft tube, a casing forming a part of the support for said turbine and provided with apertures to bypass water from said intake into the draft tube immediately beneath said runner, movable guidi-i vanes at the entrance to the runner, and means independent of said guide vanes to regulate the bypassed water by controlling the apertures of said casing.

51. In a hydraulic turbine the combination with an intake and runner, of a draft tube having a spreading portion formed by inner and outer concentric surfaces of revolution adapted to gradually turn and deoelcrate the flow and recover the energy of both the axial and whirling components of velocity, and a bypass adapted to discharge water directly from said intake into the draft tube in directions having tangential components about the turbine axis.

In a hydraulic turbine the combination with an intake and a runner, of a draft tube having a spreading portion formed by inner and outer concentric surfaces of revolution adapted to gradually turn and decelerate the flow and recover the energy of both the axial and whirling components of velocity, and a by-pass leading from the intake into said draft tube between said spreading portion and the runner and in close proximity to the runner.

53. In a hydraulic turbine the combination with an intake and runner, of a draft tube having a spreading portion formed by the inner and outer concentric surfaces of revolution adapted to gradually turn and decelerate the flow and recover the energy of both the axial and whirling components of velocity, and a bypass leading from the intake into said draft tube between said spreading portion and the runner, the passage between said surfaces of revolution being clear of any vanes so formed as to obstruct said whirling components of velocity.

LEIVIS I MOODY. lVitnesses H. S. FAIRBANKS, (l. D. life/Var.