US1545059A

US1545059A - Impulse turbine

Info

Publication number: US1545059A
Application number: US405186A
Authority: US
Inventors: Moody Lewis Ferry
Original assignee: Individual
Current assignee: Individual
Priority date: 1920-08-21
Filing date: 1920-08-21
Publication date: 1925-07-07
Anticipated expiration: 1942-07-07

Description

July 7,, 192 i y L. F. MOODY IMPULSE TURBINE Filed Auz. 21, 1920 '7 Sheets-Sheet 1 115459959 L. F. MOODY IMPULSE TURBINE Filed Auet. 21, 1926 7 Sheets-Sheet 2 Z W @51 @ltbommi L. F, MOODY IMPULSE TURBINE Filed A z. 21,-3.920 '7 SheetsSheeb 4 L. F. MOODY IMPULSE TURBINE Filed Aug. 21, 1920 '7 Sheets-Sheet 5 2/ I?! pl M 7, m5. mmsm L. F. MDODY IMPULSE TURBINE Filed Auz. 21, 1920 7 Sheets-Sheet 6 314/0014 to c 3513/ Quin 1404 5 11,545fi59 L. F. MOODY IMPULSE TURBINE Filed Aug. 21, 1920 '7 Sheets-Sheet '7 Patented July 7, 1925.

UNITED STATES LEWIS FERRY MOODY, F PHILADELPHIA, PENNrSYLVANIA.

IMPULSE TURBINE.

Application filed August 21, 1920. Serial No. 405,186.

To all whom it may concern:

Be it known that LLEWIB FERRY MoopY, a citizen' of the United States residing at Philadelphia in the county of Philadelphia I and State oi Pennsylvania, have invented certain new and useful Improvements. in Impulse Turbines, of which the following is a specification.

This invention relates to hydraulic tur? bines of the impulse type in-which the water enters the runner in free, unconfined jets having stream surfaces open to the atmosphere; and particularly to turbines of this type employing jets of circular cross-section. The object of the invention is to provide an improved turbine of high speclfic speed compared. to the specific speeds commonly attained; and-at the same time to se-' cure high efliciency, and to provide an improved apparatus for forming and control-- ling the circular jets of the turbine and thereby regulating the power and speed of the turbine in an improved manner.

Another object of, the invention is to provide acompact and simple arrangement of turbine suitable for units of great capacityunder moderately high heads. Still another object is to provide a nozzle for circular jets which is simple in structure, easily manufactured and operated and especially adapted for quick and eflicient control of the jet and thereby to provide an improved means of regulating the turbine under conditions of fluctuating load. In case of a sudden decrease in load on the turbine at correspondingly nick restriction of the flow will cause a sud en shock and water hammer, dangerously raising, the pressure in the system. To avoid this sudden restriction and at the 40 same time to reduce the driving torque so as to maintain substantially constant speed of rotation of the turbine wheel it is desirable instead of restricting the flow to first nicklv deflect a' ortion of the "jet from the uck Y ets and to o thiswithout a cumbersome or expensive structure and without distorting or disturbing the jet and causing nterference with the proper action of the etupon the wheel buckets. In particular it 18 desirable to avoid the methods of the prior art which have necessitated a variation in the shape of the jet from circular to some other form during the periods of regulation.

The jet forming means of this invention is I a radial flow nozzle in which the flow at the base of the jet converges inward and turns gradually into the axial direction on smooth lines continuously curving into a solid cylindrical 'et'directed on the turbine wheel buckets. deflecting means moving into the base of this stream diverts a portion of this flow and this. deflector preferably is symmetrical turning aside an even sheath of the jet and permitting the remainder to continue as a perfect cylindrical jet having the same axis, form. and efliciency, as a simple jet without deflection.

In the accompanying drawings illustrating the invention,

Fig. 1 is a plan view with parts in section of a turbine illustrating one embodiment of Fig. 11 is a vertical sectional view on line- 11-11 of Fig. 10,

Fig. 12 isa similar view on line 12-42 of Fig. 10,

ig. 13 is a horizontal sectional view on line 13-13 of Fig. 10,

Fig. 14 is a vertical sectional view illustrating one mountin means in relation tot e turbine wheel,

Fig. 15 is an elevational view of the same,

Fig. 16 is a vertical sectional view of a modification, and

Figs. 17 to22 are views of further modifications.

In the embodiment of the invention illusof the 'jet "forming trated in Figs. 1, 2, 3 and 4 a'vertical shaft turbine Wheel W has its shaft S extending upward through pit T to a generatorlon the power house floor above. A bearing B is provided for the shaft near the wheel and is supported by arms M resting on a ledge L at the bottom of the pit. This bearing B as shown is of the lignuin vitae type, but a babbitted bearing could be used if preferred.

In the wall of the pit T and just above the wheel W is an intake pipe P of generally circular form decreasin in cross sectional area in the direction or flow. Branching off from this pipe]? are a series of nozzles or jet forming means N guiding the water into cylindrical jets J and directing it onto the blades or buckets B of the wheel W. These buckets B are curved and inclined as shown in Fig. 3 to receive the jets at their upper ends and discharge the outflow at their lower ends downward into the, discharge passage D. The curvature of each blade is concave inthe direction of fiow and this curvature varies across the blade progressively decreasing away from the Wheel axis as indicated in the three sections at a, b, 0 in Fig. so as to give the proper blade form for the corresponding rotational velocit which of course varies directly with the distance from the axis of rotation.

The flow entering by pipe P has successive portions diverted into the branch pipes 72 12,, p and p supplying the nozzles N through annular intake passages A having the cylindrical radially directed openings I O for the flow to the base of the jets J.

- higher specific speeds are called for.

The water is thus divided between the different jets and after passing axially down between the blades of the turbine wheel all the outflows pass on into the discharge passage D without splashing or interfering with the wheel in any way.

The trend of present development is toward units of very-large capacity even when the head is not extremely high, so that For very large powers the vertical shaft arrangement is advantageous but when the tangential type of runner is used, the water discharging upward from the-upper halves of the buckets must have some prpvision for keeping it from falling back on the runner and on the jets. With vertical shaft wheels it is simpler to pass the Water through the runner downward from above rather than to admit it tangentially. The equalization of axial thrust is of little importance, since a thrust bearing must be provided to carry the weight of'the revolving parts and a moderate increase in the capacity of the thrust bearing will enable it readily to carry any additional thrust produced by the jets. This vertical axialflow arrangement is particularly suited to the use of several nozzles actin on a single wheel, without interference Between the jets. By employing circular jets all the advantages of such "ets arerealized including small friction and windage loss of the jet, ease of manufacture of the nozzle by boring and turning processes, convenience and reliability of control by a circular plunger, and the possibility of securing tight closure.

In the tangential arrangement of wheel and jet, the water enters radially with respect to the outer entrance ed e of the bucket and the relative angle 0 entrance of the jet into the bucket changes with the rotation of the bucket during the motion of the bucket through the jet. With the type of wheel here proposed, any iven part of the entrance edge of the hue et meets all parts of the jet at almost exactly the same relative angle throughout its movement through the jet, a matter of importance when the jet is large compared to the wheel, as is the case in the turbine of this invention.

In the turbine of this invention it is not only possible to use jets of much larger diameter compared to the diameter of the runner than have been hitherto employed but the possibility of arranging the jet at a much larger angle of inclination with respect to the direction of motion of the vanes than has been employed in wheels of the tangential type gives a second means of greatly increasing the specific speed over any speeds heretofore realized in impulse turbines. To explain this point, which is an essential part of this invention, refer to Fig. '3 in which the angle which the axis of the jet subtends with reference to the direction of motion of the wheel vanes is marked 0:. Although the values of this angle and of the ratio of diameters of the 'et and wheel are not extreme as shown in igs. 1 to 4, it is not intended to limit the use of this invention to the values shown, but it is intended expressly to use still larger values; and particularly it is proposed to use, when the specific speeds desired in practice call for it, values of a lying between 45 and 90 andv frequently the use of angles as high as 60, at the same time increasing the diameter of the jet until it is as large for example as the radius of the wheel measured to the axis of the jet, or even larger; The use of such values of a will require vanes inclined at a smallangle to the direction of their motion, and having very flat contours; with such a disposition of angles the linear velocity of the vanes may be made much higher than the jet velocity, a value to which impulse turbines of types hitherto used closely conform; and indeed it becomes erfectly possible to increase the wheel ve ocity to values considerably greater than the full velocity of the jet so that the jet may have a forward absolute component but a rearward relative component with respect to the charge'from the wheel to'have its velocity head increased to any serious extent by a whirl component of velocity-that is, the direction of discharge should be axial or approximatel so.

With axlal discharge the impulse of'the entering water, or the force exerted in the the quantity of water flowing. If the wheel speed is inci'eased without reducing the power, the torque exerted by the water on the wheel must be reduced. Assuming that as large a jet as practicable is being used, It cannot be reduced; W is fixed, and so is c, which depends only on the head. The re-- duction in torque can thereforebe obtained only by reducing cos a, which means an increase in the angle 01'; and this is the method upon which this invention is-based.

The wheel vanes of this invention differ radically from the buckets of tangential wheels. They are composed of straight or nearly straight line sections as cut by planes normal to the turbine axis, and have only moderate or flat curvature as cut by cylinders. WVith the large values of or here proposed the jet or jets will enter the wheel more nearly parallel to the turbine axis than perpendicular to it, and will exert more axial thrust than tangential driving force. With the efiicient thrust bearings now available this will involve no appreciable loss.

Although this invention is chiefly described as applied to vertical shaft turbines, it can also be applied to horizontal shaft wheels; and by using two oppositely arranged runners on a shaft with the feeder pipe between them for example, the jets-Will enter the wheels in opposite directions and the axial thrusts will be balanced.

The jet formation in the turbine of this invention is also new and particularly advantageous in smooth and easy regulation and in avoiding all disturbance of the jet. T he method of forming the jet is illustrated in diagrams Figs. 5'to 9, wherein Fig. 5 shows two oppositely directed nozzles 11,, a, coaxial with each other and discharging jets of equal size and velocity meeting at a central plane 9. The result will be a radially spreading sheet of Water a symmetrical on each side of the'plane p as indicated. Since the hydrodynamic principles involved in the conditions of Fig. 5 are independent of the direction of flow it may be shown that to reverse the flow and direct it radially inward along the plane 2 will in turn give two jets directed oppositely away from the plane p. For instance with an annular entrance chamber a (Fig. 6) having a cylindrical opening 0 around its inner periphery the outflow will discharge on radially converging lines and take the form of oppositely directed jets j and j, and one side may be closed oil by a wall w (Fig. 7) so as to give only one jet 7" and the base of this maybe formed around a conical projection 20'. As shown in Fig. 8v the entrance chamber a may have its surfaces d cylindrical at each side of the cylindrical opening and the same characteristic jet formation will result.

The jets j and j willbe equal and op 0- site in direction (Figs. 5, 6 and 8) buti as shown in Fig. 9, a conical wedge g with oppositely curved guiding surfaces is interposed 1n the discharge from the cylindrical opening 0 adjustment of thisswedge will vary the relative sizes of the jets dividing.

them for instance into a main jety' directed onto the wheel buckets and an auxiliary jet j directed into a casing 9 leading to the discharge passage. The uantity of water flowing through the cylin rical orifice 0 to the two jets is substantially invariable irrespective of the position of the wedge 9 so that upon a sudden decrease in load the wedge may be quickly moved to decrease the size of the main jet i without restricting the total flow or causing excesive pressure rise. This arrangement providing--a constant fiow of water into the discharge irrespective of the load on the turbine is particularly adapted for situations where a certain minimum quantity of water must be continuously passed as in many systems supplying water for irrigation purposes.

In many situations, however, it is important to get maximum power yield from the water flow and in such cases the continuous by-passing of an auxiliary stream is wasteful, it being desirable to have as little waste as possible during the periods of regulation. Under such conditions a temporary quick deflection of a portion of the jet will be sufficient to prevent overspeeding of the turbine wheel and at the same time avoid water hammer since during this temporary deflection the main flow may be gradually reduced at a safe rate, for instance by slowly restricting the size of the circular opening O Figs. 2 and 10. If the area of the opening 0 (Fig. 7) is varied as by moving the surface w the cross sectional area of the stream will be correspondingly varied as will be the force delivered by the impulse of the jet against the turbine buckets, and this will provide a means of varying the driving size.

metry of the jet but simply by reducing its In the embodiment of the invention shown in Figs. 1 to 4 and 10 to 13 the jet J emerges from the circularopening between the fixed edge and movable edge 11 of the generallyannular inlet space A. The

lines of flow through the opening O and at Y the base of the jet J converge radially and turn gradually to become parallel and axial and form a solid cylindrical stream projected at high velocit against the turbine wheel buckets. The in et space A inthe specific .end of hollow plunger 21 sliding within the inner wall 22 of the 'inlet space A. The seats 10 and ll'may be formed by replaceable rings on the casing and plunger as shown. The plunger 21 may be of the differential type providing a piston 25 with annular space 26 for fluid pressure to move the plunger inward to the left and the end space 27 for fluid pressure to move the plunger to the right. The rod 28 extends through the head 29 of the cylinder 22 and acts as a restoring connection for the governor controlling the movement of plunger 21. The rod 28 may be used to move the plunger and the fluid pressure moving means will then be omitted. v

To increase the size of the jet the plunger 21 is moved to the left to enlarge opening 0 and vice versa. The jet thus originates as a stream converging radially -toward the axis and bounded by relatively movable surfaces approximately plane. andfperpendicular to the axis. This gives an advantageous uniformity of the relation between the discharge and the plunger or gate motion, a given increment of gate motion in either direction having a corresponding and constant efl'ect on the discharge at all positions of opening. The structure is also compact, avoiding the long approach bends for each nozzle usual in the prior art and providinga simple direct entrance which can approach the wheel vertically from below as is convenient when the pipe line is carried below the floor level. In the form of plunger gate 21 shown the long needle tip commonly used in the needle nozzles of the prior art is alsogdispensed with and the water is allowed to come together closing up any cavity at the center of the stream and forming a solid cylindrical jet.

The regulation of the jet by restricting it when there is a drop in the load or enlarging it when there is a load increase is often necessarily much slower than the change in the load for a too sudden restriction or enlargement of the stream dangerously raises or lowers the pressure in the supply line. During this interval of regulation, however, the driving power on the wheel must be decreased and for this purpose a de flector d is moved into the jet to divert a portion of it so that the remainder is reduced to a safe amount. This deflector action is substantially simultaneous with the drop in load and always maintains the jet at the required value. In the specific embodiment shownthe deflector moves axially into the radially converging base of the jet J and comprises a curved tip portion 30 carried by a cylinder 31 sliding in a deflector casing 32 fastened to the main vinlet casing 33. piston portion '34 leaving

spaces

36 and 35 at each side for fluid pressure to move the deflector respectively into and out of the flow. The entering end of the deflector is formed as a sharp annular wedge curved on its inner surface to clear the streamlines and leave space for access of air around the jet and on its outer surface to divert the deflected portion of the stream as a smooth sheath. ,The angle of discharge from the deflector is preferably nearly perpendicular to the axis so 'as to be parallel to the direction of the impinging water and avoid end thrust on the deflector. This deflected sheet is directed into the discharge 'spaces of the deflector casing 32 formed for instance by the two half-volutes or double spiral 38- I (Fig.11) which empty into the discharge from the turbine and are so formed that the water will be conducted away without falling back on the deflector or interfering with the jet. For instance as shown in Figs. 1 to 4 the casing 32 surrounding the de flector d has its half spirals 37, 38 discharging into a downwardly opening outlet 39 in the discharge passage D.

The deflector d, moves into the base of the jet at right angles to the flow lines and parallel to the axis of the jet and the movement of the deflector is directly proportioned to the quantity of water deflected at each position of the deflector and also at any setting of the plunger gate 21. The deflector effectdoes not vary with different sizes of jets, therefore, but remains the same whether the jet is large or small. In all adjustments the annular deflecting edge moves directly into the unchanging and substantially plane surface of the jet base. The outer portion of the stream is diverted symmetrically all around and the inner flow lines of the jet are left unaffected to proceed as a perfect but smaller-jet. Such simple, symmetrical deflection of the flow is advantageous not only in maintaining the undeflected portion as a smooth jet without splashing or spat tering but also in the direct relation be- The cylinder 31 is provided with aa emone the same at all loads for a given increase smooth and coaxial at in wheel speed and will always be accompanied by a similarly proportioned deflection of the flow and reduction of the jet.

This jet deflection is temporary only and the deflector d is then gradually withdrawn and its reducing act-ion replaced by the continued closing movement of the plunger gate 21'narrowing the annular opening to restrict the jet to the value required by the reduced load and at a rate sufficiently slow to avoid pressure rise. 7 This recovery in the method of this invention is also expeditious and eficient and accomplished with a minirfum of waste and disturbance. The plunger and deflector moving parallel and in the same direction at right angles across the jet base maintain the delivered jet substantially invariable at its new adjustment. For the gate 21 restricts the effective flow at the same rate that the deflector recedesand adds to it, the delivered jet being all the while maintained solid, any given load and simply variant in size.

A single jet turbine illustrating one specific embodiment of the invention is shown in Figs. 14 and 15 where the wheel cordingly to receive W on shaft S is enclosed in casing C. The water enters by conduit P from the bottom and is discharged through the discharge passage D, and the jet J is directed against the lowermost buckets B and is in a plane perpendicular to the axis of the turbine wheel. The jet may be directed at an angle to this plane and the buckets modified acthe flow at one side and discharge it at the other. The jet forming and control means is simple in form and small and compact occupying a corner of the wheel casing and leading out the deflected flow within a restricted space.

In Fig. 16 is shown a modified jet forming and control means of this invention in which the cushioning deflection of the flow is of the flow to the jet instead of a portion of the jet itself as in the other figures. In this modification the intake casing 40 has 'et openings 41, 42 at each end controlled

y plunger gates

43, 44 and providing a main jet J and an auxiliary outflow whlch may be another jet 9'. The two lung'ers slide in acyligndrical housing within the casing 40 andas the main plunger 43 moves to the right to restrict the jet J, when there is a reduction in the load on the turbine wheel, the auxiliary plunger 44 will also move to the right to widen the outlet I through opening 42 so that the total quan y denly reduced. The

tity of water discharged will not be sudmove'ment of the phmga. 4 m th be reversed to the left to gradually close the opening 42 and'shut' off the auxiliary, waste or deflected stream. On opening movement of the main plunger 43 the auxiliary plunger 44 will remain closed.

The auxiliary plunger 44'may be mounted in the piston portion 46 of the main plunger as shown. The main plunger is moved to the right by the admission of fluid pressure through port 48 and the exhausting of fluid through port 49. If the connections to "ports 47 and are closed the auxiliary plunger will remain fixed relatively to the main plunger and will be carried with it. To limit themovement of plunger 43 the connections to ports 48 and 49 will be closed, and to open the plunger pressure will be admitted through port 49 and exhausted through 48. In any position of the main plunger, the auxiliary plunger is closed by admitting fluid through port 50 and exhausting through 47, and is opened by the reverse action. Rod and sleeve restoring connections (not shown) may be connected to the plungers through the discharge casing 52 or these latter connections may be used to actuate the plungers, the fluid pressure moving means being omitted. The quick regulation is effected by moving the double plunger as a whole as the'wedge g of Fig. 9 for instance; the slow water saving adjustment being then efi'ected by an expansion or contraction of the double plunger.

In the modification of the invention shown in Figs. 17, 18 and 19 the jet J is directed through an opening O in a de-' flector shield 55 andthe driving force of the jet is reduced by causing the jet to spread so that a portion of it not passing through the opening 0' will be deflected from the buckets. This spreading of the jet may be caused by one or-more adjustable vanes in the inlet spaces of the jet forming means. In the specific examples shown these vanes 60 are in the annular space 61 leading to the opening 0 and have their axes parallel to the axis of the jet. Their spindles 62 pass through the intake casing and at their other ends are provided with arms connected to controlling means for ad justing the vanes. Normally the vanes 60 are in radial positions parallel to the flow and acting to prevent a whirling of the the normal jet and spreading the latter.-

The effective jet passing through the opening 0 to the buckets will thus be reduced and as the plunger 21 moves gradually forward the vanes 60 will be returned to the radial position so that the Whole jet will pass through opening 0 the buckets.

In the modification shown in Fig. 20 the relative positions. of the plunger anddeflecand impinge on 'tor are reversed as compared to Fig. 10.

Theslow adjustment is provided by the cylindrical gate 71 sliding axially of the jet and controlling the width of opening 0 from the annular inlet chamber A. s The uick deflecting adjustment is provided by time plunger 72 formed as. a conical wedge normally having its sharp centralridge 3 in line with surface 74 or with the surface of the jet and serving by its endvsurface 75 to guide the flow into a cylindricaljet J. Upon a sudden drop in the load the plunger 72 will be thrust to the right to deflect a portion of the base of the jet into the chamber 76 and out through the discharge casing 77 thus quickly reducing the size of the jet. The gate 71 and plunger 72 will then dially toward the axis slowly move to the left so that though the amount of deflected. flow is gradually decreased the size of the jet remains at its new reduced value.

I In Fig. 21 the slow and quick adjustments are both applied to the outer lines of the jet, the central nose 80 beingfixed inposition. The cylindrical gate 81 provides the slow adjustment by moving across open ng 0, and the deflector 82 having its cutting edge 83 normally in line with or just clear of the surface of the jet is movable to the left to deflect a portion of the flow into the space 84 and out through the discharge casing 85. In the modification shown in Fig. 22 both the cylindrical gate 90 and the deflector 91 are on the opposite side of the jet from the position shown in Fig. 21, the edge 92 of the deflector being normally in line with the edge of the gate or-slightly clear of the edge. In the modifications of both Figs. 21 and 22 the quick adjustment to deflect a portion of the jet is provided by the

deflector edge

83, 92 moving axially and entering the flow to the jet so as to divert a portion thereof. The deflector then remains in its new position while the

gate

81, 90 moves into alignment with it, thus gradually cutting off the deflected flow.

In the turbine of this invention the jet thus originates as a stream converging rabounded by two ap proximately plane surfaces perpendicular to the axis and the control of this stream by an axially movable plunger makes the relation between the plunger movement and the size of the final jet a direct and simple proportion. The use of a deflector moving axially into the base portion of the jet further preserves this same simple relation between a deflector movement and the proportion of the stream diverted while the other stream lines are left to converge and turn into a perfect cylindrical axial jet simply reduced in size. means has been shown for operating the plunger in the deflector it is understood that other means, of course, could be used suchas a mechanical operation by means of a motor. If the deflector has been moved into an intermediate position the plunger can if desired then be slowly actuated so as to restore the deflector just clear of the jet, the plunger shutting off the flow at thesame rate that the relative displacement between the deflector and the surface of the jet restores it.

A further advantage of the turbine of this invention is the use of an .annular or spiral chamber as an entrance space for the jet approaching the axis of the jet radially outside of the jet orifice and in a direction perpendicular to the axis instead 'of in an axial direction as is now required by the usual design of needle nozzle. This casing surrounding the jet is preferably designed with very low velocity 'of flow compared to the velocity corresponding to the head so that the water will issueirom the orifice with clear and undisturbed flow and without whirl. It may be desirable to extend a few radial guide vanes or baflie plates across the discharge of the casing at a considerable distance from the orifice itself in order to destroy and whirl components of the water approaching the orifice and to serve as stays. The vertical shaft arrangement of Figs. 1 to 4 with axial flow through the wheel also permits a compact arrangement of nozzles connected to a common feeder, and by making the vertical component of the entrance velocity approximatelythe same as the outflow velocity the vertical thrust can be minimized. With-this arrangement it is also possible to increase the rotational velocity of the turbine wheel since the linear speed of the buckets can now be even higher than that of the jet, with resultant higher specific speed. The turbine of this invention thus combines compactness and simplicity of structure with high efficiency and large power output.

lVhile this invention has been disclosed in connection with specific embodiments there- While" fluid pressure operating of it is not confined thereto but is intended nation with means for forming a free cylindrical jet and varying its size while preserving its cylindrical form, of a rotary turbine wheel having a vertical shaft and a ring of buckets receiving said jet from above the wheel and discharging it below said wheel.

3. In a hydraulic impulse turbine of large capacity and high specific s eed, the combination with a vertical sha t wheel having buckets thereon, of means for forming a series of cylindrical jets above said wheel and adapted to direct the jets downward on said wheel and vary the size of said jets while preserving their cylindrical form, and buckets on said wheel receiving said jets from above and discharging them below said wheel.

4. In a hydraulic impulse turbine of large capacity and high specific speed, the combination with a vertical shaft wheel having buckets thereon, of means for forming a series of cylindrical jets above said wheel and adapted to direct the jets downward on said wheel and vary the size of said jets while preserving their cylindrical form, and a common feeder pipe supplying all of said jets and curved into circular form above said wheel.

5. Ina hydraulic impulse turbine of large capacity and high specific speed the combination with a; vertical sha-ft wheel having buckets thereon with backwardly and downwardly inclined surfaces, of means for form ing a cylindrical jet and directing it against said buckets from above and varying the size of said jet while preserving its cylin- CFI drical form.

6. In a hydraulic impulse turbine of large capacity and high specific speed the combination with a vertical shaft wheel having buckets thereon with backwardly and downwardly inclined surfaces, of means for forming a cylindrical jet and directing it against said buckets from above and varying the size of said jet while preserving its cylindrical form, the normal linear velocity of the buckets being greater than half the linear velocity of the jet.

7. In a hydraulic impulse turbine of large capacity and high specific speed the combination with a vertical shaft wheel having buckets thereon with backwardly and downwardly inclined surfaces, of means for forming a cylindrical jet and directing it'against said'buckets from above and varying the size of said jet while preserving its cylindrical form, the normal linear velocity of the buckets being greater. than the linear velocity of the jet.

8. In a hydraulic impulse turbine of large capacity and high specific speed the combination with a verticalshatt wheel having buckets thereon with backwardly and downwardly inclined surfaces, of means for forming a cylindrical jet and directing it against said buckets from above and varying the size of said jet while preserving its cylindrical form, said buckets being of different curvature in diiferent radial distances from the axis.

9. In a hydraulic impulse turbine of large capacity and high specific speed the combination with a vertical shaft wheel having buckets thereon, of means for forming a cylindrical jet and directing it against said buckets comprising an annular inlet space, a circular orifice opening radially therefrom, and means for controlling the flow to the jet.

10. In a hydraulic impulse turbine of large capacity and high specific speed the combination with a vertical shaft wheel having buckets thereon of means for forming a cylindrical jet and directing it against said buckets so that it is received from above and discharged below into a discharge passage, and means for deflecting a portion of said jet comprising a circular edge adapted to be interposed in the jet flow, and means for guiding the deflected flow into the discharge passage below said wheel.

11. Apparatus for forming a jet for impulse turbines comprising means for directing the flow along a plurality of lines converging toward an axis more nearly radially than axially, and means for then turning said flow toward an axial direction to deliver a jet parallelto said axis.

12. Apparatus for forming a jet for impulse turbines comprising means for directing the flow through a cylindrical orifice along a plurality of lines converging toward ly radially than axially, means for turning said flow toward an axial direction to deliver a jet parallel to said axis, and means for varying the size of said orifice to control the size of said jet.

14:. Apparatus for forming and regulating a jet for impulse turbines comprising means for directing the flow through a cylindrical orifice toward an axis more nearly radially than axially, means for turning said flow toward an axial direction to deliver a jet parallel to said axis, and means for diverting a portion of said radial flow to vary the size of said jet.

15. Apparatus for forming and regulating a jet for impulse turbines comprising means for directing the flow through a cylindrical orifice toward an axis more near- -ly radially than axially, means for turning said flow toward an axial direction to deradially than axially, and means for turnliver a jet parallel to said axis, and means for diverting a layer of said radial flow to vary the size of said jet.

- 16. Apparatus for forming and regulating a jet for impulse turbines comprising means for directing the flow along a plurality of lines converging toward an axis I more nearly radially than axially, means for turning said flow toward an axial direction to deliver a jet parallel to said axis, and means for varying the size of said jet by varying the axial thickness of the radial flow portion of the stream.

17. In apparatus for forming. a jet for impulse turbines the combination with means for directing the flow along a plurality of lines converging toward an axis more nearly radially than axially, of means for turning said flow toward an axial direction to deliver ajet parallel to said axis.

18. In apparatus for forming a jet for impulse turbines the combination with a circular orifice, of means for directing the flow therethrough along a plurality of lines converging toward an axis more nearly ing said flow toward an axial direction to deliver a'jet parallel tosaid axis.

19. In apparatus for forming a jet for impulse turbines the combination with means for directing the flow along a plurality of lines converging toward an axis more nearly radially than axially, of means for turning said flow toward an axial direction to deliver a jet parallel to said axis comprising means for varying the size of said jet byvarying the axial thickness of the jet forming stream.

20. In apparatus for forming a jet for impulse turbines the combination with means for directing the flow along aplurality of lines converging toward an axis more nearly radially than axially, of means for turning said flow toward an axial direction to deliver a jet parallel to said axis, and means for varying the size-of said jet by varying the axial thickness of the radial flow portion of the jet forming stream. 1

21. In apparatus for forming a jet for impulse turbines the combination with an inlet passage, of a surface forming an orifice receiving the flow therefrom and directing it inward toward an axis more nearly radially than axially, and guiding surfaces for turning said flow toward an axial direction to deliver a jet parallelto said axis.

22. In a paratus for forming a jet for impulse turbines the combination with an inlet passage, of a surface forming an orifice receiving the flow therefrom and directing it inward toward an axis more nearly radially thanaxially, and guiding surfaces for turning said flow toward an axial direction to de iver a jet parallel to said axis, said guiding surfaces being formed to permit the pulse turbines the combination with means for guiding the flow to said jet along lines converging toward an axis more nearly radially than axially, of means for varying the axial thickness of said radial flow to control the size of said 'et.

24. In apparatus for fbrming a jet for impulse turbines the combination with means for directing the flow to the jetalong lines converging tow'ard an axis more nearly radially than axially, of a plunger gate moving parallel to said axis and controlling the size of said jet.

25. In apparatus for forming a jet for imp'ulse turbin'es the combination with means for directing theflow along lines converging toward an axis more nearly radially than axially, of a deflector moving into the radial flow to divert a portion thereof and vary the size of said jet.

26. In apparatus for forming a jet for impulse turbines the combination with means for'directing the flow along lines converging toward an axis more nearly radially than axially, of an annular deflector moving into the radial flow to divert a portion thereof and vary the size of said jet.

27. In apparatus for forming a jet for impulse turbines the combination with means for directing the flow along lines converging toward an axis more nearly radially than axially, of an annular deflector moving into the radial flow to divert a portion thereof and vary the size of said 'et, and a discharge casing receiving the iverted flow and guiding it around said jet. I

28. Apparatus for forming and regulating a jet for an impulse turbine comprising means for directing the flow to the jet along lines converging toward an axis more nearly radially than axially, means for turning the flow into a jet parallel to said axis, means for reducing the radial jet forming flow upon decrease in the load on the turbine,

means for diverting a portion of the flow to the jet and means for then reducing said diverted portion of the flow.

29. Apparatus for forming and regulating a jet for an impulse turbine comprising means for directing the flow to the jet along lines converging toward an axis more nearly radially than axially, means for turning the flow into a jet parallel to said axis, means for divert ng a portion of the flow to reduoethe jet as the load on the turbine dro s, and means for gradually redirecting sa'i diverted portion into the jet.

. 30. Apparatus for forming and regulating a jet for an impulse turblne comprising means for directing the flow to the jet along lines converging toward an axis more nearly with an axial flow runner having buckets of jet forming means adapted to direct a cylindrical jet having its axis in a plane tangent to the circle of' said buckets, said jet being inclined to the plane of said runner at an angle of over forty degrees, and control means for said jet comprising means for changing the size of'the jet while preserv-' ing its cylindrical form.

48. In a hydraulic impulse turbine of large capacity and high specific speed the combination, with a runner of the axial flow type, of a plurality of jet producing means adapted to direct a plurality of jets in planes tangent to the circle of buckets of said runner and with the axis of each of said jets inclined at an angle of over forty degrees to the planevof said runner, and means for varying the sizes of said jets while preserving their cylindrical form.

49. Apparatus for forming a jet comprising means for directing the flow to the jet radially inward, and means for guiding the flow on one side to turn it from radial to a direction parallel to the axis, so that the surfaces of; the jet are substantially parallel planes at entrance and substantially cylindrical at discharge.

50. Apparatus for forming a jet comprising means for directing the flow to the jet radiallj inward, and means for guiding the flow on one side to turn it from radial to a direction parallel to the axis and leaving the other side open to the atmosphere so that the surfaces of the jet are substantially parallel planes at entrance and substantially cylindrical at discharge.

51. In a hydraulic turbine the combination with a runner having vanes, of jet formingmeans forming a free cylindrical jet and adapted to project the jet against I said blades-with its axis at an angle greater than 45 to the plane of said runner.

52. In an impulse turbine the combination with a runner of the axial flow type, of means for directing a cylindrical jet against the blades of said runner, said jet having a diameter greater than one fourth of the distance of its axis from the axis of the runner. 53. In an impulse turbine a runner-of the axial flow type having vanes having substantially straight line sections 'as cut by planes normal to the runner axis and having varying curvature at successive radial distances from the axis.

54. In a hydraulic turbine, a rotor comprising a series of buckets revoluble about an axis, a nozzle spaced .from said buckets and adapted to deliver a free cylindrical jet of water against the successive buckets pingement of said jet thereon and the tur-v bine will have a relatively high specific spaced from said buckets an speed, and means for adjusting said nozzle to vary the cross sectional area of said-jet.

55. In a hydraulic turbine, a rotor comprising an annular series of buckets revoluble about-an axis, a pluralit of nozzles adapted to deliver independent free jets of water against the successive buckets so that each of prising buckets revoluble about an axis,

means for delivering a free cylindrical jet of water against said buckets so that said jet forms an angle greater than forty and less than ninety degrees relatively to the line of travel of said buckets at the point of impingement of said'jet thereon whereby said turbine has a relatively high specific speed, and means for varying the cross sectional area of said jet.

0 57 In an impulse turbine of large'capacity and high specific speed the combination with an axial flow runner having buckets adapted to receive a free jet on one side and pass it through and discharge it on the other side, said buckets increasing in transverse width from the inlet side to the outlet side,- of jet forming means adapted to direct a free jet against said buckets on the entrance side,and means for varying the cross sectional area of said jet.

58. In a hydraulic impulse turbine of large capacity and high specific speed the combination with a vertical shaft wheel having buckets thereon, of means for forming a series of cylindrical jets and varying the size of said jets while preserving their cylindrical form, and directing said jets on said buckets, each of said buckets receiving said jets on a single guiding surface so that the portion of a jet traversing any one bucket remains as a single continuous body of water in passing through said bucket, said buckets discharging the water downwardly from said .Wheel.

59. In a hydraulic impulse turbine of largecapacity and high specific speed the combination with means for. forming a free cylindrlcal jet and varying its size while preserving its cylindrical form, of a wheel having a ring of buckets movable about an axis and subjected to equal pressure on all sides thereof and receiving said jet on one side ,of said wheel and discharging it on the other side of said wheel, all portions of the working surface of each bucket being inclined in the same general direction. 60. In a hydraulic turbine, a rotor comprising a series of buckets revoluble about an axis, a nozzle spaced from said buckets and adapted to deliver a free jet of water against the successive buckets in a direction so that the jet has a rearward relative component with respect to the buckets and the turbine will have a relatively high specific speed.

61. In a hydraulic turbine a rotor comprising a series of buckets revoluble about an axis, a nozzle spaced \from said buckets and adapted to deliver afree jet of water against the successive buckets in a direction so that the jet has a forward absolute component and a rearward relative component with respect to the buckets and the turbine will have a relatively high specific speed.

62. Apparatus for forming a cylindrical jet for an impulse turbine comprising an annular orifice bounded by outer and inner walls shaped as surfaces of revolution coaxial with said-jet, said surfaces of revolution being inclined to the jet axis at relatively large angles so as to direct the flow through the orifice more nearly radially than axially, and a movable plunger having an end portion forming said inner surface of revolution and turning the flow after it leaves the orifice into the axial direction.

63. Apparatus for forming a cylindrical jet for an impulse'turbine comprising an annular orifice bounded by outer and inner walls shaped as surfaces of revolution coaxial with said jet, said surfaces of revolution being inclinedto the jet axis at relatively large angles so as to direct the flow through the orifice more nearly radially than axially, and a movable plunger having an end portion forming sai inner surface of revolution and turning the flow after it leaves the orifice into the axial direction, and said plunger having a cylindrical body portion adjoining said end portion.

64. A nozzle for an impulse turbine comprising an orifice and a needle controlling the flow therethrough and means for leading the flow to said orifice comprising two passages of annular formation and decreasing area leading circumferentially around the axis of the nozzle in opposite directions and directing the flow in a diagonal inward direction toward said orifice. t

65. A nozzle for an impulse turbine comprising an orifice and a needle controlling the flow therethrough and means for leading the fiow to said orifice comprising two passages of annular formation. and decreasing area leading circumferentially around the axis of the nozzle in opposite directions and directing the flow in a diagonal inward direction toward said orifice, said passages being contained between outer and inner surfaces of revolution.

66. A nozzle for an impulse turbine comprising an orifice and a needle controlling the flow therethrough and means for leading the flow to said orifice comprising two passages of annular formation and decreasing area leading circumferentially around the axis of the nozzle, in opposite directions and directing the flow in a diagonal inward direction toward said orifice, said passages being contained between an outer surface and an inner surface of revolution having a cylindrical portion with a converging movable discharge end meeting the axis in a" point.

LEWIS FERRY MOODY.