US1008532A - Prime mover for marine propulsion. - Google Patents

Description

' 0. (1. 011111 1; 11. L. 'L'OVELL.

PRIME MOVBR FOR MARINE PROPULSION APPLIGATION FILED MAY 15,1911.

" Patented 110 1.14, 1911 APPLICATION FILED HAY 15,1911

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0. G. CURTIS & R. L. LOVBLL. PRIME MOVER FOR MARINE PROPULSION.

APPLICATION FILED MAY 15,1911.

Patented Nov. 14, 1911.

W' nesss Inventors 4 @2 4 Q Attdrneys.

UNITED sTATEs PATENT o1 anion,

CHARLES G. CURTIS, OF, NEW Y ORK, N. Y., AND RALPH L. LOVELL, O] QUINCY MASSA- CHUSETTS.

PRIME MOVER FOR MARINE PROPULSION.

steam turbines so as to secure economy of fuel, particularly at cruising speeds. In carrying out our invent-ion we couple direct to the same propeller shaft a. recip- -rocating engine and a steam turbine taking the steam flow 1n SUCCSS1OIL at cruising speeds and adapted to utilize/the entire exansion down to a condenser vacuum. For igher speeds a art or all of the steam is by-passedf direct y from the boiler to the ,steam turbine, and its complete expansion is utilized therein. V r

We prefer to use a steam turbine of the stage expansion, impulsetype, or one hav ing'initial impulse, pressure stages, with partial eri heral steam admissiom'and pref- .erab y a so. having one or more final drum sta es. Aturbine of this character which wil be adapted to utilize the steam pressure between the exhaust of thee-rigineand'the condenser, and will also be adapted to iitilizethe full expansion of the steam. from-the boiler pressureto the condenser v pressure,

can be made with such sim licit-y o'f.-parts and, moderate length, that t e-mountingof it directly on the same propeller shaft with the reclprocating engine 1s permissible. This combination has the further advantage that a steam turbine having initial impulse, pressure stages, with partial peripheral steam admission, can, practically, be made to utilize the full expansion of the steam at alower shaft speed thanthe ordinary reaction turbine with f ull'peripheral admission,

and hence notonly can 'a higher propeller efliciency be secured, but the' lower shaft 1 speed is better adapted to the conditions of e reci rocating en ne,,which, in moderate speed s ips, can be ept connected with the propellershaft soas'to furnish power there- Specification of Letters Patent. Application file (1 May 15,

Patented Nov. 14, 1911. 1911. Serial No. 627,114.

is preferably of the com )ound or two-cylinder type, a comparatively simple form of engine, and since the fuil power it is required to develop is less t ian that necessary to propel the shi at cruisi ag s eed, it can be made small an being p1 ovi ed with large bearings and forced lubri nation, can 'be run with safety at quite high speeds.

In order to make the :ombination effective, a special relation bstween the en inc and the turbine must be provided. W hen .it is attempted to utilize :he fullexpansion in a turbine of the charar ter referred to, at all speeds and powers, tlTB efficiency of the early stages of the turtine becomes very 'poor at low speed and small power, on ac? count of the low bucket s peed and also because the volume of stem 1 fiowin stage pressures required t secure ahigh efficiency. In the combination which 1s the su-bject of the present ll'lVl ntion, the exhaust from the engine is conne ated with the tur-.

iseniployed), so that the engine will workj between the boiler 'pressu re and .apressure. which maybe for exampl: from 6 to 20 lbs. absolute, while the turbine will utilize the expansion below that p int down tothe pressure of the condenser vacuum. This is the preferredarrangemen t. As a modification, a separate set of frst' stage nozzles, adapted to expand the stei m efliciently down to the back pressure, wil. be employed, to which the exhaust from he engine will be throu hthe turbine is not sufiiciei it; to maintain t e delivered. But this make necessary ,the'use of a-higher exhaust pr assure and lowerto utilize as much of the v'ailable energy as possible in the engine under these condi tions without covering too great a range of zxpansion.

At cruising speeds, the. direct supply of steam from the boiler to the first stage nozzles of the turbine will be cut oil and the entire expansion utilized successively inthe engine and the turbine. F or higher speeds live steam will be admitted directly to the first stage nozzles of the turbine, and will result in raising the pressure in the initial stages of the turbine so that the engine will work against a higher back pressure, This back pressure will inercaseas the flow of steam directly to the turbine is increased,

until the full speed conditions are attained, so that, although the speed of the engine is increased, the power which it is called upon to develop is not increased owing to the decreased range cf pressure which it utilizes. The engine will be coupled to the shaft by a suitable coupling so that it can be uncoupled at full power if desired, or atany time, for

repair or other purpose without interfering with the drivin of the shaft by the turbine.

Mounted direct y upon the same shaft ,with the engine and 'go-ahead turbine is also 'a backing turbine, whose shell may be a continuation of the shell at the low pressure end oft-he go-ahead turbine, or a separate shell. The backing turbine is likewise and i in a similar manner connected with the exhaust of the engine, and also connected d1- ing turbine.

rectly with the boiler, so that the engine can be used to add to the power of the back- A change valve is located'in the exhaust steam pipe of the engine at the point where it branches to the go-ahead and backing turbines, and this change valve is connected with the link motion of the en-- gins so that the reversing of the engine will simultaneously reverse the connection of its exhaust from the go'ahead turbine to the backing turbine. A change valve may also .be used .to control the flow of live steam di-' 'rectly to the g'o -ahead and backing turbines,

and this may also .be connected with the link motion of the engine, or the live steam con- .nections may be controlled by separate throttle valves.

' In the. accompanying drawing" formingpart hereof,- Figurel isa side elevationjand partial section illustrating a compound engine and turbine arranged so as to embody our invention; Fig. 2 is a top View of the.

sameparts; Fig. 3 is a vertical-section on line 33 in F1g.- 2, looking to the ri ht;- Figs. 4: and 5 are sectional views of one orm of valve which maybe employed forchanging the flow of steam from the go-ahead to.

the backing turbine, and vice versa; F 6 is a plan view of a modified arrangement in which the live steam connections to the oahead and backing turbine are control ed by separate valves; and Fig. 7. is a view iledstosz showing two separate sets of nozzles for the first stage of the turbine.

Referring particularly to Figs. 1 to 5A is the go-ahead turbine; 13 is the backing turbine. These may be inclosed in a single casing, as shown, and discharge in opposlte directions into the condenser Cf Each of these turbines has initial impulse, pressure stages, with partial peripheral admission, and a final drum stage." D is a compound steam engine. The shaft 6, upon which the rotating elements of the turbine are mounted, it will be understood, is connected with the propeller. The shaft .7 of the engine is coupled with the shaft 6 by aclutch 8 of any suitable form, whichmay be operated by the lever 9. The thrust block for taking the propeller thrust is shown at 10. The pipe 11 is the steam supply pipe from the boiler. The flow of steam through this pipe is controlled byjthe throttlevalve 12, from which there is a connection through the valve 13 to the high pressure chest of the" compound engine I). The valve 12 also controls the admission of steam to the pipe 14 which extends to one side'of the change" valve 15. From the change valve,15 a connection 16, provided with throttle valve 16*, is made to the steam chest 17 of the goahead turbine A; while another connect-ion 18 is made from the change valve 15 to the steam chest 19 of the backing turbine B;

"The exhaust from the low pressure cylinder so that the exhaust from theengine does not of'the compound engine passes through the valve 20, and by a pipe 21 is carried to the change valve 22. From th is change valve there is one connection 23 extending to the.

shell of the go-ahead turbine, and entering that shell at the last wheel stage so that the steam flowing through 23 will notpass through the wheel stages of the turbine but will first enter the workin passages ofthe turbine through the nozz espreceding the drum stage. From the change valve 22 there is another connection 24, leading to."

the first stage shell of the backing turbine,

30 with the link motion 31'for'reversing the' steaine ine.

It will e understood that when the lever 29 is in one position the link motion will be adjusted to cause the-engine to drive forward and at the same time the change valves 15"and'22-wil1-be adjusted to open the pipes 16 and 23 and. close the pipes 18 and 24 so that the steam will be delivered to thego-ahead turbine and cut off from reversed and the go- ahead turbine connections 16 and 23 closed and the backing turbine connections 18" and 24 opened.

While the valves 'permit of different methods of control, it is apparent that the fIIiIIlBJIlOVBI canbe controlled almost wholly y the main throttle valve 12 and the reversing lever 29. Except when it is desired to run. the shi than full spee will be left open and the speed controlled by the valve 12. When a'suflicient distance to be run at less than full speed to warrant the change, the valve 16* will be closed more orless, thus cutting down the total power developed by the turbine and, particularly,-wholly or largel cutting .out the ineffective early stages. When the valve 16 is set for any desired speed condition, lower speeds can :be secured by reducing the steam supply at the valve 12. In reversing, the control is effected entirely by the main throttle valve 12 and thereversing lever 29, the area of the first stage nozzles of the backing turbine beingsuch that when the valve 12 is open, an effective distributionof power between the backing turbine and the engine will be produced. i

i As shown in Fig. 6, the live steam con nections 16 and 18 to the go-ahead and back ing turbine may be controlled by separate hand valves 32 and 33, whilethe connections 23 and 24 from the exhaust of theengine will be controlled b a change valve22 connected with the lin 40 As shown in Fig. 7 a' separate steam chest 34, with nozzles, at the head of the first stage of the turbine, may be used to receive V the exhaust steam from theengine, instead of carrying this exhaust to one of the lowerv "being provided with a complete power stages of the turbine.

It will-be understood that the propeller shaft carrying a completesteam utilizing plant may furnish the entire power for driving. the ship, or may be used in-a two or three-shaft arrangement in which the shafts are independent of each other, each equipment of the character described.

. sion, the combination with a shaft, of a steam turbine directly coupled thereto hav-. ing a live steam connection and adapted to What we claim is y 1. In a prime moverfor marine propulsion, the combination of a reclprocatlng steam engine and a steam turbine, directly coupled to the same shaft, receiving the steam in succession and adapted to utilize the complete expansion of the steam, substantially as set forth.

2. In a prime mover for marine propulfor some distance less. the. valves 13, .20 and 16 motion of the engine.

utilize the complete expansion of the steam,- and a reciprocating steam (ngine directly, coupled to the same shaft and exhausting into said turbine, substantial; y as set forth.

3. In a prime mover for marine propul: sion, the combination with a shaft, of a steam turbine directly couple 1 thereto, having a live steam connection ndadapted at high powers toutil'ize the ct mplete expansion of the steam, and a recip rocating steam engine directly coupled to the same shaft and exhausting into 'said tlrbine at low powers, said engine being ad: .pted to utilize the steam expansion from t] e initial pressure to. an intermediate preisure,.substantially as setforth,

4. In a prime mover for marine propul sion, the combination with a shaft, of a.

steam turbine directly coupli d there to having alive steam c(')nnection :nd adapted. to utilize the complete expanslo 1 of the steam,

and a reciprocating'steam lngine directly coupled to the same shaft :nd exhausting into said turbine at an intermediate point of its'expansion range, subs initially as set forth.

5. In a prime mover for :narine propul sion, the combination of 2 reciprocating steam engine and a steam to rbine having a fixed speed relatlon and rece: vlng the steam in succession, such turbine ha wing initial in'1* pulse pressure stages with )artial peripheral admission and a final d rum stage, and a direct hve steam connectior to the turbine,

substantially as set forth.

6. In a prime mover for narine propulsion, the combination of 2 reciprocating steam engine and a steam turbine directly coupled to the same shaft an dreceiving the steam in succession, such turl me having 1n1 t ial impulse, pressure stages with partial peripheral admission, and a d: rect live steam.

connection "to the turbine, substantially as set forth.

connection to the turbine, :ubstantially as set forth. I

8. In a prime mover for marine propulsion, the combination of reclprocatlng steam engine and a steam. turbine having initial impulse, pressure stag ;es with partial peripheral admission, dire tly coupled to the same shaft, and an exh LllSt steam con" nection from "the engine to he turbine cutting out the high pressure first stage nozzles, substantially as set" for .h.

9. In a prime mover for marine propulsion, the combination of L reciprocating steam engine and a steam turbine having initial impulse, pressure stages with partial peripheral admission, directly coupled to the same shaft, and'anexhaust steam connection from the engine to the turbine, cutbacking steam turbine, all coupled directlyto the same shaft, live steam connections to both turbines. and exhaust steam connections from the engine to both turbines, substantially as set forth. a

11.111 a prime mover formarine propulsion, the cmnbination with a go-ahead steam turbine, a backing steam turbine and a steam engine. of exhaust steam'connections from the engine to both turbines, and means subject to a single control for simultaneously reversing the engine and the exhaust connet-(ions to the turbines, substantially as set forth.

12.v In a prime mover for marine propulit'n. the -on'ibination with a go-ahead steam turbine, a backing steam turbine and a ,team

engine, of exhaust steam connections from the engine to both turbines, a change valve controlling the two exhaust connections and a connection between the change valve and the link motion of the engine, substantially as set forth.

13. In a prime mover for marine propulsion, the combination with a go-ahead steam turbine, a backing steam turbine and a steam engine, oflive steam connections to both turbines and to the engine, exhaust connections from theengine to both turbines and means subject to a single control for simultaneousl; reversing the engine and the live and exhaust turbine connections, substantiallv as set forth.

This specification signed and witnessed.

CHARLES G. CURTIS.

RALPH L. LOVELL.

\Vitnesses to the signature of Charles G. Curtis:

- H. PELOUBE'I,

JOHN L. Lorscl-i.

Vitnesses to the signature of RalphL. Lovell:

AxsELo CONTI, \VnsLnv' RHODES.

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