US1286204A - Steam-turbine. - Google Patents

Description

K. BAUIVIANN.

STEAM TURBINE.

APPLICATION FILED JAN. 3| I917.

1,26,Q0% Patented Dec. 3, 1918.

3 SHEETS SHEET l- N Fig.2. ,2 M6 8 K. BAUMANN.

STEAM TURBINE.

APPLICATION FILED JAN. 3|. I917- 3 SHEETS-SHEET 2.

WITN E65 E5 K. BAUMANN.

STEAM TURBINE.

APPLICAHON FILED JAN. 3|. 1911.

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3 SHhEIS-SHEET 3.

INVENTOR KARL BAUMANN, 0F URMSTON, ENGLAND, ASSIGNOR TO THE BRITISH WESTINGHOUSE ELECTRIC AND MANUFACTURING COMPANY LIMITED, A COMPANY OF GREAT BRITAIN.

STEAM-TURBINE.

Specification of Letters Patent.

Patented Dec. 3, 1918.

Application filed January 31, 1917. Serial No. 145,708.

Lancaster, England, have invented a new and useful Improvement in Steam-Turbines, of which the following'is a specification.

Steam turbines working on high superheat and pressure are generally so constructed that all of the high pressure steam does not come into contact with the turbine cylinder in order to prevent distortion of the cylinder occurring. .Usuallv the high pressure steam is \prevented from coming in contact with the turbine cylinder by the use of nozzle boxes into which the high pressure steam is led, and from which it passes through the nozzles to the first row of moving blades.

In one construction hitherto employed the nozzle boxes have been inserted into the turbine casing through openings in the end' portion of the casing. Such openings extended over the full arc of admission and therefore considerably weakened the casing. Further more, with this construction it is only possible to admit steam over about half the circumference of the first row of moving blades. In such cases, for turbines of large outputs, the radial dimension of the nozzles and of the corresponding moving blades is very considerable, and as thewindage losses of the first wheel of the turbine increase with the blade height and the length of the circumference of that part of the ring of blades through which no steam is flowing, such losses may be unduly high.

In another construction the nozzle boxes are inserted through a slot in the side of the turbine casin The opening in the turbine casing is, in t is case, of considerable length which greatly weakens the casing. With this construction the admission of steam also takes place over about only one half the circumference of the first wheel.

The resent invention has for its object to provlde an improved nozzle box so constructed that the necessity for longand wide slots in the turbine casing for the insertion of the nozzle boxes is avoided and the strength of the casing thereb increased and also the arc of admission 0 the steam to the turbine -may be considerabl increased, with the result that for a turbine of a given outlet the-height of the blades may be decreased.

These and other objects are attained, according to this invention, by so constructing the nozzle boxes that they may be inserted endwise into the turbiiita' casing in a substantially tangential direction relatively to the moving blades through comparatively small openings provided in the side of the turbine casing.

In the accompanying drawings, Figure l is an elevation, Fi 2 an elevation at right angles to that of ig. 1, and Fig. 3 a side elevation of one form of nozzle box constructed in accordance with this invention, "Fig. 4 being a sectional view on the line IV-IV of Fig. 2. Fig. 5 is an end elevation partly sectional on the line VV of Fig. 6 of the high pressure end of a steam turbine provided with nozzle boxes of the kind illustrated in Figs. '1 to 4, Fig. 6 being a view taken on the line VI-VI of Fig. 5.

Referring now to Figs 1 to 4, the nozzle box here illustrated consists of a tapering curved tube 1 closed at its smaller end 2-- and provided at its other end with a flange 3 by which it is secured to the turbine cylinder or casing. One side of the tapering curved tube 1 is provided with a series of openings 4 throng which steam passes from the interior of the box to the nozzle openings 5, which may be conveniently formed, as

two flange portions 7, 8, attached to a lane surface 9 formed on the nozzle box. u 10 and 11 are formed on either side of the nozzle box as shown, for a purpose herein- "15, are provided within t e turbine casing to prevent movement of the nozzle boxes in the direction of the axis of the turbine, the lugs 10,.11 on the nozzle boxes being pro vi ed with tongues which slide in come shown, by guide blades 6 secured between,

sponding grooves in the lugs or supports 14, 15, as shown. In'this way the nozzle boxes are assisted in withstanding the thrust due ployment of three nozzle boxes only. A

greater or less number may, however, be employed. For example, a single nozzle box may be provided either in the top or in the lower half of the turbine.

It will be observed that the openings 20 required in the turbine casing for the insertion of nozzle boxesconstructed and arranged in accordance with this invention are comparatively small and consequently do not weaken the turbine casing to anything like the same extent as the comparatively long slots which it has hitherto been necessary to employ for this purpose.

Although a preferred construction of nozzle box has been described and illustrated in the accompanying drawings it s to be understood that the 1nvention is not limited to the constructional details described and shown, as these may be varied without departing from the spirit and scope of the invention. For example, the nozzle boxes may insome cases be straight instead of being curved as shown. Again, the improved nozzle box is herein shown as substantially circular in cross section, and while this form is advantageous for a variety of reasons the nozzle boxes may, in some cases, be made of elliptic or other suitable shape. The preferred construction also is that in which the nozzle boxes taper as shown, but this is not essential as the boxes may be made of substantially uniform width throughout. Sulpporting means other than the lugs on t e nozzle-boxes and within the turbine casing described and illustrated may be used for preventing movement of the nozzle boxes toward or away from the moving blades, provided such supporting means are so arranged as to permit of movement of the nozzle boxes relatively to the turbine casing due to difierences in expansion.

I claim as my invention:

1. In a steam turbine, a casing provided with an opening in one side thereof, a nozzle box closing said opening and extending into the casing in a substantially tangential direction, and means for supporting said box in place.

2. In a steam turbine, a casing provided with an opening in one side thereof, a nozzle box closing said opening and extending into the casing in a substantially tangential direction and supporting lugs on said box for supporting said box in place.

3. In a steam turbine, a casing provided with an opening in one side thereof, a nozzle box closing said opening and extending into the casing in a substantially tangential direction, supporting lugs on said casing and supporting lugs on said box cooperating therewith for supporting said box in place.

4. In a steam turbine, a casing having an annular offset at the inlet end thereof and a tapering curved nozzle block secured in an opening in said ofi'set portion and extending in a substantially tangential direction relative to the turbine blades.

5. In a steam turbine, a casing having an annular ofiset portion at its inlet end,

'a series of tapering curved nozzle boxes entered through openings secured within openings in said ofi'set portion and extend ing tangentially to the turbine blades.

In testimony whereof I have hereunto subscribed my name this second day of 'January 1917.

KARL BAUMANN.

Witnesses W. Moms, F. Nrssox.

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