US1027697A - Elastic-fluid turbine. - Google Patents

Description

\ ter throughout, and at the same time with UNITED STATES PATENT OFFICE.

CHART- 1E3 G. CURTIS, OF NEW YORK, N. '11, 'ASSIG-NOR, BY MESNE ASSIGNMENTS, T0

GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

ELASTIC-FLUID runnmn.

racemes. May 28, 1912.

Application filed November 12, 1906. Serial No. 342,956.

To all whom it may concern Beit known that 1, CHARLES (learns, a citizen of the United States, residing in the borough of Manhattan, in the city, county, and State of New York, have invented a certain new and useful Improvement in Elastic-Fluid Turbines, of which the following is a description.

The object I have in, view is the production-of an elastic fluid turbine, which will have certain advantages over those hereto fore suggested. 1

The invention is applicable particularly to turbines'for marine use, having a horizontal shaft and being of the axial flow. or parallel flow type, but its use is not so limited.

The invention comprehcnds the use of a plurality of stages each of which contains a plurality of rows of moving buckets alternating with fixed nozzles, but the invention may be carried out with but a single stage. Each nozzle is adapted to converta certain portion of the pressure belonging to that stage into velocity.

In order to get the proper theoretical conditions in a. turbine employing alternate rows of annular nozzles and moving buckets, the buckets and nozzles in the initial stages will have to be undesirably shallow or,el se the rotating element in the initial stages must lJQIllllC-ll. smallerin diameter than in the succeeding stages. Such turbines are ob ject ionable therefore inn having the early stages of too small a diameter or with too shallow buckets.

,An object ofthis invention is to avoid these objections and to permit the rotating element to be of practically uniform diameout undesirable shallowness of buckets in the initial stage.

The drawings ihustrate one form of mechanism for carrying out my invention.

Figure l is a view partly in section of one stage of a turbine embodying my invention; Fig. 2 is a development of the nozzles and moving buckets shown in Fig. 1; and Fig. 3 is a view partly in section, but upon a reduced scale, at right angles-to Fig. 1.

In all the views, like parts are designated by the same reference characters.

As shown in Fig. 1, the turbine is formed with the shell 1. within which the wheel 2 rotates. The shell is divided into stages by means of diaphragms 3, and the end of the shell is covered by a head 4. The space be tween the head and a diaphragm, or between successive diaphragins, constitutes a stage. Within each stage are alternate rows of buckets and liked nozzles. The first nozzle 5 in a stage is carried by the head t or a diaphragm 3, as shown. The successive nozzles 6--6 are shown as supported from a block 7,

securedto the shell 1. Other means than that illustrated may be used for supporting the nozzles. Between the nozzles are the rows of moving buckets 8. These buckets, as is customary, are closed in with rims. The

depth of-the nozzles and moving buckets stage, the successive rows of nozzles toward the exhaust increasing in peripheral length. As a typical form of construction, the nozzles in the first stage, of-six or more stages, may occupy about 3; of the periphery of the shell, while the last stage may extend all the way around. This is for the purpose of per mitting a greater depth of nozzle andmoving buckets for the high pressure stages, and a less depth of nozzles and buckets for the low pressure stages.

The block 7 is shown as making a tight joint with the nozzle 5. This prevents leakage of steam from the nozzle up intojth'e shell, above the nozzles; The leaka efliioward' the center ofthe shell isprevented. y inean's ofa lip g, which stands closeto an'annular fiange,gtornied within the rotating element. This lip llf'iiiay be un'adjustable or adjustable, and may be similar to that disclosed in my Patent No. 725,032. There will be a certain leakage of steam around this iipfi but the amount of leakage will be small. iere will also'be a certain amount of leakage at the front and back ends'of the nozzles, but this leakage will be small. Thestdfini leaking 15 first of the nozzles 6.

30 may be utilized in succeeding stages.

into the caing around the lip 9 and at the forward and back ends of the nozzles, will pass into the other side, that is, the discharge and of the stage, by any suitable means, such as through the tube 10 shown as formed in the rotating element. Some steam will escape around the upper edge of the first now of moving buckets, but it will be caught and will be compelled to pass 10 through the second nozzle, therefore no steam can escape in this direction into the shell. There will be some leakage of steam after it passes through the first row of moving buckets around the lower edge of the The steam, however, has no opportunity to escape except through the sccond'row oi. buckets 8, where it can do useful work.

It will be seen that the steam is quite tclosely confined to the passage through the fnozzles and only a very small proportion of it gcan escape. The greater portion of the steam must pass through the nozzles and moving buckets. None can upward into the shell and very little will pass out 5 of steam will pass around the bottoms of the succeeding nozzles, and that steam will be utilized in the successive rows of buckets. After the steam has passed through the moving and stationary elements of the tur- 40 bine, it will be collected in the discharge end of the stage in front of the diaphragm 3, and will then discharge through the nozale 5 into the next succeeding stage.

The invention is not limited to turbines in which the pressure is confined within the shell and an equal conversion made in each nozzle, but on'the contrary, the amount of conversion in the nozzles may not be uniform. As an example, Where threenozzles 5, 6, 6 are shown, each may develop equal energies or 33-),% each. As another example, thahbzzle 5 may develop 50% of the total enel 'gy in the stage, and the first of the nozzles 6, 30%, and the second of the nozzles 6, 20%, in which case the two nozzles 6, 6 will function partly as nozzles and partly as guide buckets. These figures are solely for the purpose of illustration, as I do not confine myself in any way to the an amount of conversion of each nozzle.

The number of nozzles and moving buckets in each stage may be modified, if desired, those shown. being for purposes of illustration only. l urthermore, the invention is 5 not to be limited to a stage turbine, as all of the moving buckets may be made within a single stage.

An advantage of my invention, over turbines in which the velocity is nearly all produced by the nozzle at the beginning of the stage is an improved elliciency. This is caused by an equalization of the velocities in all buckets, because the nearer the velocity is evenly divided among the several rows of buckets, the greater is the efficiency. A further advantage is that the buckets and intermediate nozzles may be all of the same shape, thus reducing the expense of construction, and sin'iplifying repairs and replacements.

It may be found preferable .to arrange the nozzles to occupy less than the whole of the periphery of the wheel in the higher pressure stages only, as theiperipheral length of the nozzles will increase toward the exhaust. At a certain point in the turbine these nozzles may extend all the way around the shell so as to discharge in a continuous annular sheet.

The invention may be used in connection with turbines employing any elastic fluid as a motive power,-steam being chosen solely as an illustration.

In accordance with the provisions of the patent statutes, I have described the principle of my invention, together with the apparatus which I now consider .to represent the best embodiment thereof; but I desire tohave it understood that the apparatus shown is merely illustrative and that the invention can be carried out in other Ways.

Having now described the nature of my invention and the manner in which the same is to be performed, what I claim as my invention and desire to secure by Letters Patent'is: v

1. An elastic fluid turbine, having a stage composed of a plurality of rows of nozzles and rows of moving buckets alternately arranged, the nozzles extending around less than the whole periphery, and an annular lip for reducing leakage of motive fluid from the first nozzle into the shell, the remaining nozzles being so arranged as to leave no open space between themselves and the shell, and closely approaching the moving element of the turbine to reduce leakage over the ends of the nozzles.

2. An elastic fluid turbine having a stage in which a certain portion of the expansion takes place in the working passage beyond the nozzle, the said nozzle extending around less than the whole periphery, and means for confining theflnid at the clearances to restrict its escape into the shell until it has left the working passage.

3. An elastic fluid turbine having a shell, a nozzle at the beginning of a stage, so formed as to have a considerable end presi 5 for confining the fluid at the clearances so Witnesses:

meme? v a less than the whole periphery, and means sure, a certain portion of the expansion tek- This specification signed and witnessed ing piece in the working passage beyond this seventh day of N0"e1nher,1906. the nozzle, the said nozzle extending around CHARLES CURTIS as to partially prevent its escape into the LEONARD DYER, shell until it has left the working passage. N0- ROBT. TAYLOR.

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