US811984A - Elastic-fluid turbine. - Google Patents

Description

No. 811,984. 11117111117511 FEB. 11, 1906.

J. WILKINSON, ELASTIC FLUID TURBINE.

APPLIGATION FILED MAYZZ, 1905.

U NITED STATES PATENT OFFICE.

JAMES WILKINSON, OF PROVIDENCE, RHODE ISLAND, ASSIGNOR TO WILKINSON TURBINE COMPANY, A, (JORP ORACIION OF ALABAMA.

ELASTIC-FLUID TURBINE.

Specification of Letters Patent.

Patented Feb. 6, 1906.

Application m May 22,1905. Serial No. 261,676.

To (all whom it HI/(by TOM/081":

Be it known that I, JAMES WILKINSON, a citizen of the United States, residing at, Providence, in the county of Providence and State of Rhode Island, have invented new and useful Improvements in Elastic-Fluid specifiduce the overload-supply of fluid into the initial stage or first wheel-com artment, and

since the overload capacity 0 such turbines is usually about fifty per cent. of their estimated full-load capacity the cross-sectional area of the overload-nozzles will be substantially one-half of that of the supply-nozzles. This proportion may be varied'in accordance with the requirements for each engine, but is here adopted as merely illustrating general practice. Assuming then that the turbine 1 illustrated has an overload capacity of fifty per cent, I prefer to use as many overloadnozzles as there are supply-nozzles, designing them to have a capacity of about fifty per cent. of the supply nozzles and arranging each overload-nozzle in juxtaposition to and cooperative relationship with a supply-nozzle. I provide the initial stage to which these nozzles admit fluid-pressure with a discharge nozzle or nozzles, preferably one for each pair of cooperating nozzles.

The introduction of the overload-supply of fluid-pressure to an initial stage requires that the turbine be specially designed to utilize this excess volume of fluid with the highest elliciency. Accbrdingly I provide the turbine with an initi 1 stage having supply-nozzles designed to ,onvert a relatively larger percentage of pressure into velocity than is converted by t iesup v ly-nozzles for succeed= ing stages and rows 0 buckets to fractionally abstract the velocity-from the expanded streams of motor fluid a suilicient number bf times to produce a speed of bucket rotation substantially corresponding with. that obtained by the rotating buckets in the succeeding stages which are acted upon by the fluid .at a lower velocity. This initial stage, in which the high fluid velocity is iractionally abstracted, I term a velocity-stage, whereas the succeeding stages are termedfpreswith. single rows of buckets, sothat there will be no fractional abstraction in them of the fluid velocities developed by the successive expansions of the fluid in supply-nozzles for the pressure-stages. If the initial velocity-stage be provided with norn1al-load supply-nozzles designed to expand the fluidpressure to such a volume that the capacity of'the nozzles required to discharge it efficiently into a succeeding pressure-stage will substantially correspond with the combined nozzles, the efliciency of the turbine under unaffected by the provision of the overload nozzles, whereas when the latter are brought into service this efficiency will not be materially reduced, for the pressure will be raised in the first stage to a point where it becomes substantially e ual to the. initial high-pressure supply am the discharge-nozzles from the velocity-stage will act as supply-nozzles for the succeeding pressure-stages, of which there may be a large number, or for the succeeding working passage of the turbine, whichmay be of any desired character. A turbine having any desired number of pres sure-stages may thus be provided with an initial velocity-stage at its supplyend, the norhaving a cross-sectional area approximately two-thirds of that of the stage-nozzles discharging thereirom. It will be evident that only a'small number of rows of buckets are necessary for the velocity-stage in any case, even Where the'turbine has a large number of pressure-stage compartments succeeding the velocity-stage. The nozzles which connect the several stage-compartments subsequent to the first two being properly proportioned in accordance with the increase in volume of the fluid as it is fractionally expanded in flowing through them will act at substan tially the same ei'liciency whether the initial sure-stages and are preferably provided normal-load conditions will be substantially capacity of both normal and overload supplymal-load supply nozzles for the latter stage pressure be that of the motor fluid as supplied to the first stage or as expanded therein and discharged therefrom under normal conditions I I desire to protect, broadly, a turbine having the initial or supply end of its working passage formed as a velocity-stage i. 6., one provided with a bucket element adapted to operate efliciently under fluid moving at greater velocity than in other parts of the Working passage, said velocity-stage having discharge openings so proportioned to the fluid-admission openings that under an overload condition the motorfiuid is caused to bank'up in said stage until it practically flows therefrom into the succeeding portion of the working passage at substantially the same pressure as that of the fluid-pressure supply to the turbine.

My invention further consists in the details of construction and arrangement of parts, in

describing which reference will be made to the accompanying drawings, forming a part of this application, in which- Figure 1 is a side elevation of the turbine provided with my improvements and broken away to illustrate a portion oi the working passage across stages for the fluid-pressure.

- Fig. 2 is a partial sectional view taken on a the sectional inner casing together.

circular axial plane through the turbine, which will illustrate the construction and arrangement of parts constituting the working" passage.

Similar reference-numerals refer to the same parts throughout the drawings.

The turbine as illustrated comprises an outer casing 1, surrounding the several die phragms 2, which divide the interior of the turbine into wheel compartments or stages, their outer flanged peripheries abutting and forming the inner casing of the turbine. A locking-ring 3 is detachably connected to the outer casing l and serves as an abutment which engages the supply-head 4 and holds Vlithin each stage is disposed a bucket-wheel 5, keyed to the turbine-shaft 6, which projects through the supply-head 4 and the exhaust-head 7 and is supported in suitable bearings 8, mounted upon the bed-plate 9, which supports the turbine. The bucket-wheel 5 in the first or velocity, stage is provided with two rows of buckets 10, between which is disposed a row of stationary intermediates 11, suitably, secured to the inner casing. These intermediates are curved in the opposite directionto that of the buckets 10.

Fluid-pressure enters the turbine through an inlet -passage 12, which communicates with a supply-passage 13, formed in the head 4. From this sup ly-passage a number of nozzles 14 lead ob iquely through the head and discharge fluid-pressure against the buckets 10. The turbine may be provided with any desired number of these nozzles suiiicient to take care of all normal load conditions to which it may be subjected-in other words, to deliver suflicient fluid-pressure to the turbine to operate it up to what is termed full load or approximately that. To take care of overload conditions to which the turbine may be subjected, I provide a number of auxiliary overload-nozzles 15, which lead in the same oblique direction through the supply-head, each auxiliary nozzle being preferably disposed in close relationship with one of the nozzles 13'. I provide separate valves 16 and 17 to control the admission of iiuidpressure to the nozzles 14 and 1:), respectively. It will be noted that the overload nozzles 15 are of considerably smaller capacitythan the supply-nozzles 14, as they will not be called upon in the construction illustrated to supply fluid-pressure to take care of more than a fifty-percent. overload. Since I desire to provide an overload-nozzle for cooperation with each supply-nozzle, it will be evident that the-former will deliv r sufiicient fluid-pressure for overload conditions if they are substantially half the capacity of the nozzles '14. The stage into which the supply-nozzles discharge is the velocity-eta and it will be noted that the bucket-whee in each of the succeeding stages is pros J with but a single row of buckets 18.

fluid-pressure supplied to the velocity-stag] is partially converted into velocity in the supply-nozzles, and: this velocity is fraction ally abstracted by the rows of bucketslfi, at ter which the fluid-pressure is discharged through a nozzle or nozzles 19 against the buckets 18 in the next stage, each dischargenozzle being disposed so as to receive the streams of motor fluid delivered to the velocity stageby its corresponding cooperating nozzles 14 15 and to further expand the same. The steam flows through each of the succeeding diaphragms through stageuiozzle passages 20 of increasing proportions to accommodate the expanded condition of the fluid, any desired number of succeeding pressure-stages being used. 19 are preferably subdivided by division plates 21, starting at a point near the inlet end and continuing to the discharge end of the nozzle.

The nozzles 18 and I The supply-nozzles 1 9 for the first pressure of motor fluid as initially supplied to the velocity-stage. The working passage for the motor fluid discharged from said velocitystage may be of any desired character within the scope of my invention, it only being necessary to so design the buckets and the stationary guides or nozzles as to roduce a speed of bucket rotation substantially e ual to that obtained by the buckets in the ve ocity-stage.

Under normal conditions the stream of Inotor fluid flowing through a nozzle 14 will be expanded thereby and also by its action upon the buckets in its passage through the velocity-stage, so that the discharge-nozzle 19 forthat stage will be properly proportioned to receive the fluid in its expanded condition and discharge it at high efficiency into the first pressurestage. for the velocity-stage being proportioned rol atively to the first nozzles 19 in the line of the fluids flow, it will be evident that the turbine under these conditions will be operating at highest efficiency. It dVerload conditions occur, one of the overload-nozzles will be opened. This presents a condition inlwhich the cross-sectional area of the pair of open cooperating nozzles will substantially equal the cross-sectional area ofthe corresponding discharge-nozzle It will therefore be evident that the velocity-stage will tend to become a high-pressure supply-chamber for nozzles 19, and they will discharge more motor fluid into the succeeding pressure-stages than before. The velocity -stage being a small fraction of the turbine, the fact that the fluid does little or no service therein during the-overload, conditions is more than comp ensated for by the increased power derived our the large number of rows of buckets for the succeeding Working passage, due to the greater volume of motor fluid flowing therethrough. The greater the number of overload-valves open in the first stage the greater will be the pressure therein, and it will be evident that when they are approximately'all open they will have the effect of raising the ressure 1n the velocity-stage to a point where it substantially equals that of the initial sup ply, in whichcase the steam will flow through i the velocity-stage as through a steam-supply passage and exert its driving effect in the succeeding working passage. Thus the variation in the power derived from the fractional abstractions of velocity in the velocity-stage under overload conditions will not materially effect the general efliciency of the turbine.

The nozzle-valves may be operated b hand, having stems 22, which project through the head, and have handles 23, as shown, or any desired governor-controlled mechanism such as shown in my aforesaid Letters Patent may be used to operate them.

The su ply-nozzles for the several stages maybe 0' any desired shape or proportion as the design of the turbine may require to best carry out the operation lioreinbefore described, and a similar operation may be obtained where the velocity-stage has only a slngle row of buckets, provided its supply- The supply-nozzles 14f nozzles are designed to expand the fluid-pressure sufliciently. l

Having thus described an illustrative embodiment of my invention, but without hiniting myself thereto, what 1 claim as new, and

desire to protect by Letters Patent, is--- 1. In an elastic-fluid turbine, a working passage for the motor fluid therein comprising successive rows of rotating buckets, means to deliver the motor fluid at greater velocity to the first row or rows of buckets than to the succeeding rows, and means to discharge fluid from said buckets subjected to the higher velocities, said means con'sistingoi openings of substantially the same cross-sec' tional area as the initial fluid-supply openings, for-the purposes described.

2. In a turbine, rows of nozzles cooperating with rows of revolving buckets, bucketvWheels supporting said buckets and. disposed inseparate wheel-compartments in combination with fluid streams for moving said buckets, means to cause the streams to act with greater velocity on the first row or rows of buckets than on the succeeding rows, and independent valves for cutting said streams into and out of service, said nozzles being so pro ortioned for the first stages that when sai valves are open, the-row or rows of buckets in the first wheel-compartment are substantially cut out of service.

3. In a turbine, the provision of a,,velo'citystage compartment, motor-fluid supply and discharge openings therefor of substantially the same cross-sectional area, rotatable buckets therein, means to control the supply of -motor-fluid to said compartment, and a work ing passage comprising stationary guide devices for the fluid and interposed rows of rotating buckets into which passage the motor fluid flows from said velocity-stage compartment and in which the velocity developed in its passage through the turbine is abstracted. I

4. In a turbine, a compartment and means therein for fractionally abstracting velocity from fluid-pressure and converting it into rotary motion, fluid supply and discharge ports for said compartment of substantially the same cross sectional area, valve means to IOO IIO

vary the supply of fluid to said compartment,

and one or more compartments having means therein to further abstract velocity from the fluid-pressure discharged from said first-mentioned compartment.

5. In a multistage turbine, supply-nozzles and cooperating buckets for each stage adapted to drive the turbine under normal-load conditions, the supply nozzle or nozzles for the initial stage being ada ted to convert a reatcr per cent. oi the flui -pressure into veocity than the succeeding nozzles and one or more overload-nozzles adapted to discharge fluid-pressure, to compensate overload conditions, into said initial stage, the cross sectional area for lhe discharge opening or openin s for saidstage corresponding substantia 1y with the combined cross-sectional area of the nozzles supplying fluid-pressure thereto.

.6. In a turbine havingoa lurality of separate compartments to Whic the fluidpressure is delivered in succession, nozzleas sages connecting said compartments an rot-atable buckets Within said stageswhich co operate with said nozzle-passages and convert fluid velocity into mechanical power, in combination with a plurality of nozzles for admitting an overload supply of pressure to the turbine, said overload-nozzles being equal in number with the supply-passages for the compartments into which they discharge, but

of less capacity! 7. In a multistage turbine in which the fluid-pressure is fractionally ex anded, the

' comblnation with'a supply-nozz e for an initial stage, of anoverload supply-nozzle arranged in juxtaposition to said supply-nozzle, and a discharge-opening from said initialstage formed by a nozzle-passage leading to a succeeding stage, said nozzle-passage being disposed in line with the fluid streams flowing through said supply and overload nozzles and being of a capacity calculated to cause the motor fluid to flow through thesaid initial stage without material driving effect upon the-buckets therein when the overload-no izle is in service. v

8. In a multistage turbine having a Pinrality. of supply-nozzles for an initial stage designed toadmit sufficient fluid to drive the turbine up to its full load capacity, the com- "'In testimony whereof I have hereunto set my handin presence of twosubscribing witnesses.

JAMES WILKINSON.

Witnesses S. G. JAMEsoN, J. J. DEVENISE.

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