US1235992A - Steam-turbine. - Google Patents

Description

J. F. METTEN.

STEAM TURBINE.

APPLICATION FILED NOV. 11. 1916.

Patented Aug. 7, 1917.

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& sons sure & Enema BUILDING oomrnnr, A oonrom'rroiv or rnmv- STEAM-TURBINE.

Patented Aug. 7, or 1.

Application filed November 11, 1916. Serial No. 130,735.

To all whom it may concern:

Be it known that I, JOHN F. ME'ITEN, 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 Steam-Turbines, of which the following is a full, clear, and exact specification.

This invention relates to steam turbines, and has particular reference to improvements in high speed turbines especially adapted for geared marine propulsion, wherein it is desirable to provide a maximum amount of power in a given volume.

In systems of high speed compounded turbines which have been developed especially for geared marine propulsion, there is usually a high pressure, high speed turbine preferably composed in whole or in part of all wheel stages, and the low pressure turbine may be composedof drum stages. In some instances, the low pressure unit is of the divided flow drum stage type, receiving the steam from the high pressure unit and dividing it between two drums. These divided flow low pressure units either take the steam at the middle and expand it toward each end, or take the steam at each end and expand it toward the middle. The object of dividing the low pressure turbine unit into two parts connected in parallel is to reduce the lengths of the exhaust blades, and a more common shaft deflection. Where the condenser is connected at the ends, the glands have to be packed against the high condenser vacuum, and these glands require continual care in order to prevent air leakage or loss of steam through the glands directly to the condenser.

The present invention has for its object to provide a low pressure, high speed turbine of especial advantage for. geared-marine propulsion, in which the reversing turbine will be incorporated in the same casing withoutpossible to be obtained by substantial increase of length between bearings, and providing symmetrical construction. The steam is supplied at each end and flows toward the middle, which subjects the glands to the low pressure steam and thus reduces the air leakage through the, glands and loss ofsteam through the glands. In this construction, the reverse turbine is located at thev center between the two parallel connected low pressure turbines, and can be of one stage because of the high blade speed diameter. I

- A preferred form of the invention is shown in the accompanying drawing, wherein- Figure 1 is a section of a turbine embodymg the invention, and

Fig. 2 is a diagram of a geared propul- S1011 system embodying this turbine.

1 is a turbine casing, 2 the shaft, 3 the pinion, and bearings 4:, 4, which will conbearings 4 will be both subject to the low,

pressure steam, which as above stated will ordinarily be steam delivered from any high pressure turbine in series with the low pressure stages 7, 7, the stages 7, 7, as shown herein, being themselves in parallel, and the drums balanced.

9 represents a steam belt or chest opposite the chamber 8 which will be supplied with high premre steam, and having a sufficient number of nozzles 10. as will pass the amount of steam required for reversing. The high pressure steam passes from the nozzles v10 through the blades of a single velocity compounded stage 12 driving wheel 13 on shaft 2 in the reverse. direction. The nozzles 10 may extend partially or wholly around the periphery of wheel 13 to give the desired admission of steam.

In Fig. 2, 14 is a high pressure high speed wheel stage turbine having a pinion 16, and discharging by pipe 17 to the low pressure the large wheel inlets 5. The pinions 3 and 16 are geared to a gear 18 on shaft 19 carrying a propeller 20.

In normal forward running, the steam will of course 'be shut ofi from the steam belt or chest 9 and the reversing wheel 13 will be operating idly in the condenser" vacuum. Both the low pressure stages 7 will be operating in parallel under the relatively low pressure steam, but at high speed. By thisconstruction, the turbine as a whole is symmetrical, and the shaft deflection is reduced to a minimum because the relatively heavy low pressure stages are placed near the bearings. lhis becomes especially important in high speed work, because shaft deflection is objectionable by reason of increasing the steam losses and necessitating larger cleanances, and also because of the possibility of stripping the blades. 0wing to the large pitch diameter and corresponding increased blade speed the single reversing'turbine is greatly simplified. Also, the packing glands are not required to pack against the high vacuum of the condenser, but only against the pressure at the inlet ends of the ahead blading, thus assuring less possibility of air leakage, or gland steam loss directly to the condenser, as compared with the usual arrangement where the glands are subjected to I shafts, a two flow low pressureturbine in steam parallel to drive the other of said two'- shafts, the two parts of said last'mentioned turbine being arranged to'exhaust toward each' other into a common space, and a reverse turbine located between said parts in 7 said exhaust space.

2. In a geared marine steam'turbine arrangement, a low pressure turbinefdivided into two parts and connected. in steam parallel, taking steam at each end and exhausting to a common exhaust opening at center, in conjunction with a reversing compound velocity wheel carried in the exhaust space between said two low pressure ahead parts.

3. In ageared marine high, speed low pressure turbine comprisingtwolow pressure ahead parts designed to work in parallel and exhausting to a common exhaust chamber at center, and a reverse turbine consisting of a compound velocity wheel located in middle exhaust chamber,- a high pressure steam belt for reversing turbine located in masses said outlet, a separate source of steam supply located in said exhaust chamber, and a smgle wheel .stage reversing turbine cooperating therewith and discharging into said exhaust chamber. 7

6. A turbine comprising a casing having a steam inlet at each end and an intermediate exhaust outlet, a series of drum stages adjacent each end between saidinlet and said outlet, a separate source of steam supply located in said exhaust chamber, and a single wheel stage velocity compounded reversing turbine codperating therewith and discharging into said exhaust chamber.

7. In a geared marine steam turbine propulsion system, a high pressure unit, a plurality of low pressure units driving a common shaft each in series with said high pressure unit, said low pressure units exhausting into a common space between them, and a reversing turbine located on the same shaft in the exhaust space between said low pressure units.

8. In a geared marine steam turbine propulsion system, a high pressure unit, a plurality of low pressure units driving a common shaft each in series with said high pressure unit and exhausting into a common space, a reversing turbine located on the 'sameshaft between said low pressure units insaid common exhaust space, a pinion driven by said high pressure unit and a second pinion driven by said low pressure units, and a gear and propeller shaft driven by said pinions.

" "9. In combination, two turbines on the same shaft, a common casing therefor, live steam inlets through the casing at the opposite ends, said turbines exhausting toward each other within the casing,-and a reversing turbine in the exhaust space within the easing between the first mentioned turbines on the same shaft therewith.

10.. In combination, a shaft, two ahead turbines on said shaft adapted for steam flow toward each other, a reverse turbine between them on the same shaft, and a common casing for all said turbines.

11. In combination, a shaft, two ahead turbine rotors thereon adapted for steam flow toward each other, a reverse turbine rotor on said shaft between said ahead turbine rotors, a casing surrounding all three said turbine rotors, and corresponding stators carried by said casing.

12. In combination, a casing, a shaft through the casing having bearings in the end walls thereof, steam inlets through the casing adjacent to said bearings, two turbines within the casing on said shaft receiving steam respectively from said inlets and with the steam flow therethrough directed toward the middle of the casing. and an intermediate turbine between said two turbines on the same shaft therewith with a steam inlet for said intermediate turbine through the side wall of the casing.

13. In combination, a propeller, a shaft therefor, a large gear on said shaft, two pinions engaging said gear on opposite sides thereof, respective shafts for said pinions, a high pressure turbine driving one'of said shafts and three turbine units on the other said shaft, two of said three turbine units receiving steam in parallel from the high pressure turbine and discharging into a common exhaust space between them, and

the third said turbine unit being a reverse turbine in said exhaust space between the other two units.

14. 'In combination, a high pressure turbine, two low pressure turbines on the same shaft adapted for opposite steam flow and to exhaust toward each other, means to conduct exhaust steam from the high pressure turbine and divide it to the two low pressure turbines, and a reverse turbine between the two low pressure turbines on the same shaft therewith.

15. In combination, two shafts, a high pressure turbine on one shaft, two low pressure turbines on the other shaft adapted for opposite steam flow toward each other, a reverse turbine between said two low pressure turbines on the same shaft therewith, and a propeller connected to be driven by the rotation of said shafts.

In testimony whereof I aflix my signature, in presence of two Witnesses.

7 JOHN F. METTEN. Witnesses: HOWARD Dn'mMAN, Fmncrs L. GRAMP.

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