US769272A - Marine steam-turbine. - Google Patents

Description

PATENTBD SBPTfa, 1904.

G. A. PARSONS. MARINE STEAM TURBINE.

APPLICATION FILED JUNE 27, 1902.

[SHEETS-SHEET 1.

N0 MODEL.

No. 769,272. PATENTED SEPT. 6, 1904.

O. A. PARSONS. 'MARINE STEAM TURBINE.

- APPLICATION FILED JUNE 27, 1902.

, N0 MODEL, 2 SHEETS-SHEET 2. S

J ttcsllx I QC/dbr Civics)? 3 0 SUNITEDI STATES Patented September 6, 1904.

PATENT OFFICE;

MARINE STEAM-TURBINE.

SPECIFICATION forming part of Letters Patent No. 769,272, dated September 6, 1904. 1 Application filed June 27, 1902; Serial No. 113,501- (No model.)

To all whom it may concern:

Be it known that I, OHARLEs ALGERNON PAR- soNs, engineer, a subject of the King of Great Britain and Ireland, residing at HeatonWorks,

Newcastle-upon-Tyne, in the county of Northumberland, England, have invented certain new and useful Improvements in Marine Steam-Turbines, (for which I have made application for Letters Patent in Great Britain, No. 24,515, dated December 2, 1901; in France, No. 317,003, dated December 18,1901; in Germany, application filed December 19, 1901,

very low rates of speed and correspondinglyvery reduced horse-powers. The present arrangement, however, is for obtaining economies at, cruising speeds, which are often above the limits of rotational speeds at which reciprocating engines can safely be worked for long periods of time.

My invention is intended to provide acornbination of cruising and full-power steam-turbines and is an improvement upon the invention which forms the subject of the abovementioned application, Serial No. 15,163. It

is also an improvement upon the patent already granted to me, No. 608,969, dated August 9, 1898.

To carry out the invention'in warships such as battle-ships, cruisers, or torpedo-boat destroyers'the main turbines consist of one high and two low pressure turbines driving separate shafts. The low-pressure turbines are coupled to two cruising-speed turbines secured to prolongations of the main low-pressure-turbine shafts and carry small and numerous rows of blades. These'cruising-turbines consist of a high-pressure turbine and an ntermediate-pressure turbine. They are of such capacity that they can only pass thecomparatively small volume of steam required for cruising purposes. When cruising at the lower rates of speed, the steam from the boiler passes successively through the high-pressure turbine and the intermediate-pressure cruising-turbines and thence to the main highpressure turbine and on through the two lowpressure turbines to the condensers, thus securing a very high degree of expansion of steam and. high coefficients of efficiency in the turbines when they are running at reduced speeds. a portion or the whole of the boiler-steam is admitted to the intermediate-pressure cruis- VVhen higher speeds are required,

the main turbines. Under the latter condition I prefer to run the highepressure cruis' .1ngturbine idly, a backflow of steam from the intermediate pressure cruising turbine into the high-pressure turbine being prevented by a non-return valve in the pipe which connects these two turbines. Inorder that the high-pressure turbine shall then revolve with very little resistance, I may place it in direct valve-controlled communication With the condenser. It will then run idly in the condenser-vacumn. The non-return valve above referred to maybe, however, dispensed withand the high-pressure cruising-turbine run idly in high-pressure steam; but as this turbine is relatively small its resistance is inconsiderable. Still higher rates of cruising speed can be obtained by admitting additional boiler-steam into the main high-pressure and low-pressure turbines. It is desirable to interpose non-return valves between all the turbines to prevent a backfiow of steam into the higher-pressure turbines when steam at boilerpressure is admitted directly to the main turbines. For obtaining intermediate grades of speed between those above mentioned I may provide the high and intermediate cruising turbines with steam-inlets at intermediate positions in their lengths. The cruising-turbines are perfectly steam-balanced in themselves and are coupled to the low-pressure turbine-shafts by any suitable coupling, either fixed or detachable.

Referring now to the accompanying draw;

.i do

ings, Figure 1 is a plan of the turbine arrangement, the piping being shown diagrammatically only. Fig. 2 is an elevation of a portion of the piping to the high-pressure cruising-turbine. Fig. 3 is a sectional View of the non-return valve drawn to an enlarged scale.

The main turbine set consists of a highpressure turbine a, mounted upon the central shaft y, and two low-pressure turbines b and 0, mounted upon shafts m and 2, respectively. The shafts m and 2 are extended forward of the low-pressureturbines and have mounted upon them the cruising-speed turbines (Z and e, of which the former is the high-pressure turbine and the latter the intermediate-pressure turbine. The turbines (Z and e have small and numerous rows of blades and are'of' such capacity that they can only deal with the comparatively small volume of steam required for cruising purposes. When it is desired to propel the vessel at low rates of speed, steam from the main steam-pipe f passes by Way of the stop-valve ]L, the branch pipe j, pipe t', T-piece 70, valve m, (see Fig. 2,) and pipe n to the highpressure turbine (Z. After passing through this turbine the steam flows through the pipe 0 to the intermediate turbine e, thence by pipe p to the main highpressure turbine a, and thence by pipes qq to the low-pressure turbines b and c and by way of the exhaust-bends 1* 1" into the condensers s s. The steam thus passes through all the turbines in series into the condenser, and thereby secures a very high degree of expansion of steam and high coefiicient of efficiency in the turbines when they are running at slow speeds. It will be seen that this follows from introducing a much larger number of steps by employing additional turbines. hen a somewhat-increased rate of speed is required, additional steam at boiler-pressure may be admittedto the high-pressure turbine d at a point intermediate in its length by way of the valve t and steam-pipe it. Then higher rates of speed than those above referred are required, a portion or the whole of the boiler-steam is admitted to the intermediate turbine c by the steam-pipe r, T-piece w, and pipe 2. In this case I mayrun the turbine cZ'idly in the highprcssure steam communicated to it from the turbine 6 through the pipe 0; but I prefer to place a non-return valve 3 in the pipe 0 to prevent backflow of steam into the high-pressure turbine. This valve is hereinafter described in detail with reference to Fig. 3 of the drawings. As the high-pressure turbine is relatively small, its resistance to rotation in highpressure steam is inconsidcrable. In some cases, however, I connect it directly with the condenser by means of a suitable valve-controlled pipe, (not shown in the drawings,) so that it may rotate idly in the condenservacuum. The turbineemay also be provided With an intermediate live-steam admissionpipe 4 and valve 5 for the same purpose as the pipe a and valve 7?. The shafts to which the turbines (Z and are secured may be detachably coupled to the shafts .1: and .2, so that the turbines may be stopped, if desired, when the main turbines alone are in operation. Still higher rates of speed can be obtained by admitting steam direct from the boiler to the main high-pressure turbine (r. This may be effected by means of the branch pipe 3', stop-valve 7, breeches-pi m 8, and the two steam-pipes 9 9. To prevent a backflow of steam from the main high-pressure turbine a into the intermediate-pressure turbine w, a non-return valve 11, similar in construction to but larger than the valve 3, is interposed in the pipe p.

In some cases where even higher rates of speed than above referred to are desired l supply steam at boiler-pressure to the main low-pressure turbines by the valve-controlled pipes 12 12, and I employ non-return valves 13 13 in the pipes q 1 to prevent a baelrllow of steam into the main high-pressure turbine.

The turbine and piping arrangements are only shown diagrammatically in Fig. 1, and the arrangement for reversing the turbines and operating auxiliary machinery, which form no part of the present invention, are omitted, so that the drawing may be more clearly understood.

When the turbine set consists of high-pressure, intermediate-pressure, and low-pressure turbines on three shafts, as used on the Tum- ?)z'n/ia and described in the specification accompanyingmy Serial No. 620,719, filed .lanuary 26, 1897, the additional turbine set consists, preferably,of one cruising-turbi ne only, with a non-return valve in the piping which connects the turbine in series with the turbines of themain set. The turbine which comprises the additional set is conveniently mou nted upon an extension of the center low-pressure-turbine shaft.

Although I have only mentioned two cruising-turbines in the case illustrated in Fig. 1, I do not limit the number to two. Larger n umbers of cruising-turbines and different arrangements and graduations may be used, according to the circumstances of the case, so long as these turbines are additional to the turbine sets forming the main engines and are of capacity adapted to cut down the steam used to that required for cruising purposes.

The non-return valve 3, hereinbefore referred to, is illustrated in Fig. 3. .l,l1el1anged neck 16 of the valve-chest opens toward the high-pressure turbine (Z, and the neck 17 opens toward the intermediate-pressure turbine a.

When the pressure of the steam at the exhaust end of the turbine (Z is greater than that at the inlet end of the turbine 11, it lifts the valve against the tension of a very light spring 15, attached to the end of a pivoted valve-lever 14, thereby enabling a flow of steam to capacity mounted upon a corresponding numtake place from the high-pressure turbine to the intermediate-pressure turbine. When, however, steam direct from the boiler is ad: mitted to the intermediate-pressure turbine, the pressure of steam; there will be in excess of'the exhaust-pressure of the high-pressure turbine, and the valve 3 will automatically close and prevent a bac'kflow of steam to the high-pressure turbine. The other non-return valves 11, 13, and 13 are of the same construe-- tion as and they operate in a similar manner to the valve 3. Expansion-joints 18 may be provided between the non-return valves and the-turbines, as seen in Fig; 1.

Having now described my invention, what I claim as new, and desire to secure by Letters Patent, is Y 1. A system of turbines for propelling vessels consisting of a main turbine set for propelling the vessel with high economy at fast speeds, and an additional turbine set adapted to be put in series with the main turbine set when the vessel is to be propelled with high economy at cruising and low speeds, and automatic means for preventing a backflow of steam from the main turbine set to the additional turbine set when the former set is propelling the vessel at fast speed, substantially as described.

2. A system of turbines for propellingvessels, consisting of a main turbine set for pro;

pelling the vessel with high economy at fast speeds and an additional turbine set adapted to be put in series with the main turbine set for propelling the vessel with high economy at cruising and slow speeds, the former set comprising a plurality of turbines of large ber of propeller-shafts, and the latter set comprising a plurality of'turbines of relatively small capacity mounted upon extensions of the propellerrshafts, substantially as set forth.

3. A system of turbines for propelling vessels, consisting of a main turbine set for propelling thevessel with high economy at fast speeds and an additional turbine set adapted to be put in series with the main turbine set for propelling the vessel with high economy at cruising and slow speeds, the main set comprislng a high-pressure and two low-pressure turbines of. large capacity mounted upon separate propeller-shafts, and the additional set comprising a high-pressure turbine and an intermediate-pressure turbine mounted upon intermediate-pressure turbine, piping con- 'nectlng the additionalturbine 1n serles wlth the main turbine set, non-return valves in said piping between the turbines, and valvecontrolled live-steam inlets to each turbine of both sets, substantially as set forth.

5. A system of turbines for propelling vessels, consisting of a main turbine set for propelling the vessel with high economy at fast speeds and an additional turbine set for pro' pelling the vessel with high-economy at oruising and slow speeds, the main set comprising a plurality of turbines of large capacity and the additional set comprising a plurality of turbines of relatively small capacity, piping putting the cruising-turbines in series with the main turbines,non-return valves in this piping between the turbines of both sets,

valve-controlled live-steam inlets to each turbine, and additional live-steam inlets situated at intermediatepositions in the lengths of the turbines of the cruising set, substantially as set forth.

In witness whereof I have hereunto set my hand in presence of two witnesses. 4

CHARLES ALGERNON PARSONS. Witnesses: 1

, HENRY GRAHAM DAKYNS, J unr.,

WILLIAM MENZIEs JOHNSTON.

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