US1520783A - Hydraulic turbine - Google Patents

Description

H. B. TAYLOR HYDRAULIC T RBINE Original Filed July '24 1917 2 Sheets-Sheet 1 Ili my w Ill",

7 INVENTOR i flZJLzM 7% TORNEKS H. B. TAYLOR HYDRAULIC TURBINE Dec. 30, 1924. 1,520,783

Original Filed July 24, 1917 2 Sheets-Sheet 2 /5 /& 16 /5 IN VEN TOR PNEYS Patented Dec. 30, 1924.

UNITED STATES HARVEY BIRCI-IARI) TAYLOR, F PHILADELPHIA, PENNSYLVANIA.

HYDRAULIC TURBINE.

Original application filed .Tu1y 24, 1917, Serial No. 182,498.

Serial No. 557,921.

To all whom it may concern:

Be it known that I, HARVEY BIROI-IARD TAYLOR, a citizen of the United States, residing at Philadelphia, in the county of Philadelphia and State of Pennsylvania, have invented certain new and useful Improvements in Hydraulic Turbines of which the following is a specification.

The principal object of my invention is to provide a new and improved substructure for a hydraulic turbine of the inflow type and particularly to such a turbine having a straight draft tube receiving the discharge from the runner. Another object of my invention is to provide suitable supporting means for such a turbine and its associated masonry structure. Another object is to make a stay vane ring to go in the draft conduit of such a turbine. Still another object of my invention is to provide columns or piers in the draft conduit beneath such a turbine that shall be effective as supports for the superposed structure and at the same time have the proper disposition as vanes with respect to the water flow in the conduit.

These and other objects of my invention will be made apparent in the following disclosure of a limited number of examples of forms in which the invention may be embodied.

In the accompanying drawings illustrating the invention,

Figs. 1 and 2 are vertical and horizontal sectional views respectively of a turbine structure embodying the invention,

Figs. 3 and 4 are similar views of modifications, and

Fig. 5 is a vertical sectional view of a further modification.

The turbine runner 12 has vanes 11 and is of the vertical shaft type. The supply conduit 13 terminates in a spiral or volute portion 14 surrounding the runner 12. A speed ring 15 is provided directing the flow to the adjustable guide vanes 16 so that the entering flow has a whirl imparted to it around the axis of the runner as a center.

Directly below the runner 12 there is an ordinary straight draft tube 17 with vertical axis. Below this is a stay vane ring having v the vanes 18 extending diagonally across the annular flaring conduit between the crown ring 19 and the conical core 20. The surfaces of the crown ring 19 and conical core 20 are surfaces of revolution forming Divided and this application filed May 2,

between them an annular flaring passage 21 receiving the flow in substantially axial direction from the straight draft tube 17 and turning it outward to the radial or horizontal direction and at the same time lowering both the meridian and whirling velocity components and thus acting as a diffuser to create a suction or draft lowering the back pressure on the draft tube 17. The surfaces of revolution 19 and 20 when out by a meridian plane,-as seen in Fig. 1, curve sub stantially along arcs of concentric circles the arc of the outer surface having a radius much smaller than that of the inner core surface so that the overall dimensions of this annular passage are small both vertically and horizontally. Since the arcs of the outer and inner surfaces 19 and 20 are substantially concentric, these surfaces are equally spaced apart and the linear width of the passage remains substantially the same from entrance to discharge. The passage 21 has an annular outlet 22 into a chamber 23 which extends upwardly around the barrel formation 24 of the lower end of the draft tube 17. This chamber 23 (Fig. 2) has no special provision for absorbing the whirl component of the discharge from the draft tube 17, 21 but simply receives the water after its available energy has been recovered by the draft tube and conducts it through the discharge passage 25 to the tailwater T. Dependence is here placed on the vanes 18 for the recovery of the energy of whirl possessed by the water flowing in the tube 17. The vanes are formed to reduce all components of the velocity in the tube with as little loss of energy as pos sible; for this purpose they are suitably curved to receive the water in its natural direction of flow and to provide a gradually increasing cross sectional area measured perpendicularly to the stream elements between neighboring vanes. In this way the natural diffuser or decelerating action of the annular passage is smoothly and symmetrically maintained.

The draft tube of this invention may be arranged to operate either with the chamber 23 and discharge passage 25 completely submerged, or with the tail water surface reduced to an elevation below the top of this chamber as shown in Fig. 1 where the tailwater level T is such that there is a free surface of tailwater within the chamber.

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The modification shown in Figs. 3 and 4 corresponds to that of Figs. 1 and 2 except that a stay vane ring with vertical stay vanes 31 is employed and the central conical core is omitted so that the flow is left to turn outwardly through the annular outlet 32 without central guiding surfaces. The stay vanes 31 are designed to assist in the hydraulic operation of gradually reducing the velocity of the water. while flowing between the vanes. For this purpose they are suitably curved'to receive the water in its natural direction of flow and to provide a gradually increasing cross sectional area measured perpendicularly to the stream elements between neighboring vanes. As will be apparent from Fig. 3 the diameter of the draft tube 17 increases uniformly going downwarduntil the level of the upper edge of the crown ring 19 is reached and then the diameter enlarges at an increasing rate for further positions below. Thus it is apparent that the draft tube shown in Fig. 3 flares increasingly as it approaches the bottom wall 33in which the base ring 30 is embedded.

In the embodiment of the invention disclosed in Fig. 5 the general design is much the same as for Figs. 3 and 4 but in Fig. 5 the draft tube 37 is formed not merely as a void in the concrete structure 88 but has a sheet metal lining 39 which stands on the crown ring 19' of the stay ring. At its upper endthis sheet metal draft tube lining 89 has a flange attached tothe base ring 40 of the speed. ring. In this embodiment of my invention I have also shown a metal turbine casing 41 for the supply water conduit in place of the conduit formed in the concrete used in preceding figures. The weight of the turbine and other parts is carried by the concrete surrounding the tube 37 to the stay ring and thence to the foundation. The plate steel lining 39 serves merely as a form for setting the concrete and lining for the tube and is not essential as a part of the structure carrying this superposed load.

In the turbine structure of this invention the whirling draft tube discharge is received in a straight draft tube with gradually diverging walls adapted to decelerate the meridian velocity of the flow and the lower end of this draft tube is provided with a diverging passage decelerating both the meridian and whirling components of velocity of the flow so as to further increase the suction and effective head on the runner. At the same time the construction is simple in formation and provides a continuous columnar support from the foundation through to the speed vane around the runner and thence to the superstructure above.

This application is a division of my original application Serial Number 182,498, filed July 24, 19.17.

I claim 1. A draft tube for a hydraulic turbine comprising a central conical core and a guid- .ing passage adapted. to spread. and turn the outflow around said core, an enlarging conical passage coaxial with the turbine, interposed between the turbine runner and said passage, and a circular series of stay'members supporting the walls of the draft tube from the foundation.

2. A draft tube for a hydraulic turbine comprising a central conical. core, an en? larging conical passage, coaxial. with, the.

turbine, interposed between the turbinerunner and said core, side surfaces extending, from said passage and cooperating-with said 80 core to form an annular passage in continuing in cross section in the direction offlow, and a circular series. of stay. members supporting the walls of the draft tube from the foundation.

4. A draft tube for a turbine. comprising an enlarging conical passage coaxial, with the turbine adapted to decelerate the discharge, an annular passage betweeninnerand outer flaring surfaces of revolution receiving the flow from said conical passage in an axial direction and turning it toward the radial direction while decelerating. both meridian and whirling components ofvelocity of flow, and a circular series of stay members supporting the walls of thedraft tube from the foundation andformedto-receive the water in its natural whirling direction of flow.

5. A draft tube for a turbine comprising an enlarging conical passage coaxial with;

the turbine adapted to decelerate'the discharge, an annular passage receiving the. flow from said conical passage andguidlng it toward the radial direction while decelerating both meridian and; whirling. compo, nents of veloclty of flow, said annular.v passage being contained between a central con'i;

cal core and outer surfaces of revolution and a circular series of stay memberssupporting the walls of the draft tube fromthe founda tion.

6. A draft tube for a t-urbinecomprising.

a straight expanding passage adapted, to de= celerate the d1scharge,and an annular. pas.- sage receiving the flow from, said stral ht.

assa e and uidin ittoward the ra ial. P a: a b

from said passage and cooperating withsaid core, said 001110211. passage and the. passage.

between said side surfaces and core increasdirection while decelerating both meridian and whirling components of velocity of flow, said annular passage being of undiminished linear width and contained between a central conical core and outer surfaces of revolution beginning in substantially the same plane normal to the axis of rotation and terminating at substantially the same distance from the axis.

7. In a draft tube for a turbine a straight expanding passage and an annular flaring passage comprising a central conical core having a surface of revolution concave toward the axis, and an outer surface of revolution convex toward the axis and having the radius of its meridian section less than two thirds of the radius of the meridian section of the central surface of revolution, said surfaces being spaced apart to form a passage gradually increasing in transverse area to decelerate the flow and convert velocity head into pressure head.

8. In a draft tube for a turbine a straight expanding passage, and an annular flaring passage comprising a central conical core having a surface of revolution concave toward the axis, an outer surface of revolution onvex toward the axis, said surfaces of revolution having their meridian sections as arcs of substantially concentric circles so that the linear width of the passage between them is substantially constant.

9. In a draft tube for a turbine a. straight expanding passage, and an annular flaring passage comprising a central conical core having a surface of revolution concave toward the axis, an outer surface of revolution convex toward the axis, said surfaces of revolution having their meridian sections as arcs of substantially concentric circles so that the linear width of the passage between them is substantially constant and a circular series of stay members separating the walls .of the draft tube from the foundation.

10. In a turbine the combination with a discharge outlet chamber formed in solid concrete having a horizontal floor and an upper surface above the surface of tailwater, of a draft tube leading from the turbine runner to said chamber and comprising an annular concrete barrel portion depending from the upper surface of said chamber and terminating in an outwardly directed discharge along the floor of said chamber.

11. In a turbine the combination with a discharge outlet chamber formed in solid concrete having a horizontal floor and an upper surface above the surface of tailwater, of a draft tube leading from the turbine runner and extending below said tailwater surface and comprising an annular concrete barrel portion terminating in an annular flaring passage having a central conical core merging with the floor of said chamber.

12, In a turbine the combination with a discharge outlet chamber formed in solid concrete having a horizontal floor and an upper surface above the surface of tail water, of a draft tube leading from the turbine runner and extending below said tailwater surface and comprising an annular concrete barrel portion depending from the upper surface of said chamber and terminating in an outwardly directed discharge along the floor of said chamber, and a stay vane ring supporting said barrel portion from the floor of said chamber.

13. In a hydraulic turbine having a substantially axially directed discharge from the runner the combination with a straight expanding draft tube passage, of an annular flaring draft tube passage formed between an outer surface of revolution curving from a substantially axial to a substantially radial direction and an inner surface of revolution curving from axial toward radial, said annular passage receiving the flow axially and gradually turning it and decelerating it and delivering it outward, and a surrounding collection chamber having its upper surface above the outlet of said annular flaring draft tube passage and adapted to receive and collect the flow and turn it toward tailwater.

14. In a hydraulic turbine having a substantially axially directed discharge from the runner the combination with a straight expanding draft tube passage, of an annular flaring draft tube passage formed between an outer surface of revolution curving from a substantially axial to a substantially radial direction and an inner surface of revolution curving from axial toward radial, said annular passage receiving the flow axially and gradually turning it and decelerating it and delivering it outward, and a surrounding collection chamber having its upper surface above tailwater level and adapted to receive and collect the flow and turn it toward tailwater.

15. In a hydraulic turbine having a substantially axially directed discharge from the runner the combination with a straight expanding draft tube passage, of an annu- Iar flaring draft tube passage formed be tween an outer surface of revolution curving from a substantially axial to a substan tially radial direction and an inner surface of revolution curving from axial toward radial, said annular passage receiving the flow axially and gradually turning it and decelerating it and delivering it outward, and a surrounding collection chamber having its upper surface above the outlet of said annular flaring draft tube passage and adapted to receive and collect the flow and turn it toward tailwater, said collection chamber having a side wall spaced from said annular passage at all points.

HARVEY BIRCHARD TAYLOR.

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