US760898A - Impulse-turbine. - Google Patents

Description

PATBNTED MAY 24. 1904.'

A. G. lazlplvIIcHBLLl IMPULSB TURBINE.' APPLICATION FILED JULYM, 1903.

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To all whom', t may concerni- UNITED STATES Patented May :334, 1904. i

PATENT OFFICE.

IMPULSE- MELBOURNE, lVICTORIA,

Tulelma.A

SPECIFICATION forming part of Letters Patent No. 760,898, dated May-24, 1904.

Application filed July 14, 1903. Serial No. 165,457. (No inodel.)

Be itknown that I, ANTHONY GEORGE MAL- DON MICHELL, civil engineer, a subject of the King of Great Britain, residing at Commercial Union Chambers, No. 409 Collinsstreet, Melbourne, in the State of lVictoria and Cornmonwealth of Australia, have invented an Impulse-Turbine, of which the following is a specification.

My invention relates to a turbine devised for a new mode of operation or rule of action;

and the essential novelty consists in the arrangementof an impulse-turbine wheel with a circumferentialA ring of curved vanes approximately tangential at their outer ends and approximately radial at their inner ends, saidl vanes extending inwardly for about'one-third of the radius and surrounding a relatively large central space which allows of the flow of the water -transversely in a manner and for a purpose hereinafter disclosed. The wheel in Operation is acted on by a nearly tangential jet or jets of water which both enters and is discharged by the outer ends of the vanes.

The course of the water .within the wheel is, however, entirely different at di'erent speeds of rotation, andto produce these different effects is the object'of the special construction which Iernploy. e

After describingthe construction of the turbine in connection withv the drawings I will more fully explain the Inode of action' and its advantages. l

It is to be understood that the wheel may be employed with its shaft Y. either vertical or horizontal, its action being the same in both CLSCS.

grammatic elevations illustrating-the action of the wheel. Figs. 7 and 8 are views similar to Figs. 2 and 3, showing modes of construction suited to special circumstances.

The turbine-wheel consists of two circular i disks or shrouds (marked VA A in all' the {igures) and of vanes B B, which are arranged in'V an annular series around the circumference of the wheel and between the shrouds. In Fig. 2 fboth shrouds A A are shown provided with Ybosses C C for mounting upon the shaft D,

e which is continuous through thewheel. Fig. 3 shows an overhung wheel mounted upon the shaft D by means of a single boss C upon'one lshroud.

` The vanes B B, as shown Vin Figs. l and 4, Iare curved, so as Ito be nearly tangential at `their outer ends and diverging towardv their inner ends, said inner endsextending substantially radially to the disks, as shown. The `vanes occupy onlythe 'outer portion of the space between the shrouds, preferably extending inward forapproxirnately one-third ,of the radius, the relatively large inner space being open and in free communication with The angle be-VA f the spaces between the vanes.

tween the circumference of the wheel and the vanes at their outer ends, though small-#that is to say, not more than about thirty degrees at most--must be greater than the angle at which the jetof water meets the circumference.l The inner ends of the `vanes are vpreferably exactly radial if the shaft, as in Fig. 3, does not enter the space between the shrouds; but when, as shown in Figs. 1 and.y

2,A the shaft passes through the wheel the vanes are to be only approximately radial and directed to the front side of the shaft, reckoning in the direction of tlie'mpo'tion of the vane, as indicated in Fig. 1. V Q

The water may be applied to fthe wheel either in a single jet from a nozzle of circular or other section, as E, Fig. l, or from a nozzle with guide-vanes, as shown at e e, Fig. 4.

The latter arrangement, 4which, is well known in the art, is particularly suitable for the operation of my turbine with large quantities of water, as it enables a large jet to be directed nearly-tangentially in all its parts. The width of the nozzle in all cases is to be somewhat'I less than the width of-.thewheel between its shrouds.

The construction of thewheel being as described, its action is as follows: The water delivered in a nearly-tangential jet will at starting and at low speeds of the wheel pass inwardly through the ring of`vanes and nearly diametrically across the central air-space and will be discharged by the vanes opposite to those through which it entered. This action is shown in Fig. 1, in which the streams of water are indicated by dotted lines. At working speeds, on the contrary, the inwardlymoving water is retarded on account of the rapid rotation of the wheel, comes nearly or quite to rest upon the vanes, and then reverses its motion and is rediseharged from their outer ends without crossing the central space. This action is shown in Fig. 6, in which the dotted circle indicates the inner edges of the vanes. At intermediate speeds of the wheel the water follows an intermediate course, as shown in Fig. 5, traversing the inner circular open space upon a chord, which 'lies the farther from the center the higher the speed. The working peripheral speed of the wheel is rather greater than one-half of the velocity of the jet. With the vanes extending through one-third of the radius the water will be retained in the vanes, as shown in Fig. 6, when the peripheral speed exceeds three-fifths of the velocity of the jet. I find that at the workingand all lower speeds the water is chiefly discharged at a point in space approximately opposite the point of entrance and that at all such speeds the pressures acting on the vanes at these points combine to turn the wheel, but largely counterbalance one anothers tendencies to cause lateral pressure on the bearings. low speeds if the water were not discharged across the central space. Also, the water being retained at high speeds between the vanes into which it is delivered, irregular scattering and fluid-friction are then minimized, while by the transverse delivery at low speeds the discharged water is prevented from fouling the incoming jet. To fully attain this last advantage, it is preferable when the axis of the wheel is horizontal to deliver the jet at or near the highest point of the circumference and discharge it near the lowest point. I find that if the vanes extend through much more than one-third of the radius the spaces between their inner ends will at Working speeds be too narrow to carry the Water, and the proper action will be interfered with. If, on the other hand, the vanes are much shorter, the working speed of the wheel must be so high as to lead to loss of efficiency.

This would'not be the case atv In order to enlarge the spaces between the inner ends of the vanes I may make the shrouds, as shown 1n Fig. 7 somewhat concave on their inner sides, thus making the vanes B B wider at their inner than at their outer ends.

As a convenient means of utilizing large quantities of water I may combine two or more of my wheels, as shown in Fig. 8. In this construction the shrouds A A, with their bosses C C, are formed exactly as in Fig. Q; but intermediate disks F F are employed, which together with the shrouds support several rings of vanes B B. Each set of vanes may have its own nozzle, or a single nozzle may be employed of suliicient width in the direction of the axis to supply all the sets of vanes.

Having now particularly described and ascertained the nature of my said invention and in what manner the same is to be performed', I declare that what I claim is4 l. An impulse-turbine water-wheel, coniprising a shaft, a pair of circular disks lixed on said shaft, aseries of curved vanes arranged between the circumferential portions of said disks, said vanes being curved in the same direction and extending through approximatel y one-third of the radius of the disks, the outer ends of said vanes extending approximately tangentially to the disks, said vanes diverging toward their inner ends, and said inner ends extending substantially radially to the disks, all so arranged that an inner een tral ai rspace is formed which communicates only -with the spaces between the vanes, thus subjecting the latter to the transverse ilow of the water, substantially as shown and described.

2. An impulse-turbine water-wheel comprising a pair of circular disks concave on their adjacent inner sides, and an annular series of curved vanes arranged between the circumferential portion of said disks and extending through approximately one-tliird of the radius of the wheel, said vanes being arranged nearly tangential at their outer ends and nearly radial at their inner ends, substantially as described.

In testimony whereof I have hereunto set my hand in presence of two subscribing witnesses.

ANTHONY GEORGE lllAlillON llllClllllili.

Witnesses:

EDWARD VATERS, Jr., WILLIAM HERBERT lVA'runs.

IOO

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