US1475267A

US1475267A - Elastic-fluid turbine

Info

Publication number: US1475267A
Application number: US574511A
Authority: US
Inventors: Junggren Oscar
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1922-07-12
Filing date: 1922-07-12
Publication date: 1923-11-27
Anticipated expiration: 1940-11-27

Description

Nov. 27,1923

O. JUNGGREN ELASTIC FLU) TURBINE Filed my 12. 1922 F'igu.

inventor:

7 size the buckets in thelower Patented Nov. 27, 1923'. I

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Q B. G EN'Y FQ QHENEQ D NEW YORK, AssIeNoafTo GENERAL anaemic r communacoaroaerron or vnw YORK. r

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1 Application filed Jui f12, 1922. Serial no. 574,511.

To all whom it may concern i Be it known that I, 'OSCAR JUNGGREN, a citizen of the United States, residing at Schenectady, county of Schenectady, State of New York, have invented certain new and useful Improvements. in- Elastic-Fluid Turbines, of which tle following is a speci-, fication. 1

The present invention relates to elastic.

fluid turbines of the impulse type andparticularly to nozzles for such turbines. As iswell understood, the nozzles are stationary, fluid-directing elements which serve to expand the elastic'fluid, thereby converting pressure into velocity, and direct it against the adjacent bucket ring of the rotating wheel. In general, the nozzles are formed by mounting or arranging guideblades or partitionsbetweentwo 'radially spaced concentric rings, the structure as a' whole being termed a nozzle diaphragm. The nozzles may extend entirely around the for complete periphpart way around.- 7 a In multistage turbines of considerable become quite long so that there is considerable difference in speed between the roots and the tips of the buckets, and" as the elastic fluid speed is constant in any particular stage it means that the speed through the tips of the buckets is slower than that through the roots; and since the tips are traveling faster than the roots it'follows that the elastic fluid is discharged from the tips of the buckets in a forward direction,

1. e. in the direction of motion of the buckets. In fact, as will be apparent from a. consideration of the foregoing, the elastic fluid will be discharged from the buckets in a continuously varylng direction from the roots of the buckets to their tips.

Prior to my invention, so far as I am aware, it was the practice to make the entrance edges of the nozzle partitions radial and the entrance angle of the nozzle plates the same throughout their length and as the elastic fluid issuing from the adjacent bucket ring strikes them at varying angles the result has been the setting up of eddies in the nozzle passages, water cutting of the nozzle partitions, and improper filling of the nozzle passages, particularly in the case of flared nozzlesan improved. nozzle pressure stages I The object of" v rz le di ph agm structure and arrangement come the above difliculties sideration of'wha'tfI believe to be novel. and my invention, attention, is directed-to the accompanying description and, the-claims appended thereto.

"and 'for a. con

invention is to, provide which will over- In the drawin'gEig. l is a radial sectional viewthrough anozzle diaphragm and a d jacent bucket wheels. fluid turbinQ, the nozzle diaphragm having nozzles embodying my. invention ;.-I1lig. 2 is a perspective view on fan enlargedsca'le of several adjacent nozzle 'partitions theouter ring being omitted,and- F igst 3, 4; and5 are diagrammatic sectional, views taken on lines 3-3),1-4 and 55, F'i I Referring to the drawing, 10 indicates. a nozzle diaphragm 'havingf nozzlej partitions 11. The entrancev edges-of the. nozzlepartitions are designated [12 and the discharge. edges l3.- The bucket wheels of thestage'sj preceding and following diaphragm .10 areindicated 14: and 15,, andgit will be under stood. that the elastic fluidleavingjthe, buckets of'wheel'l i enters the, nozzles, of diaphragm 10 and, is directed by such;

of an axial flow elastic nozzles: to the ring of; buckets on wheel, 1 5..1

The section of F 1 is. taken through-one.

of the lower pressure stages of a,turb'ine1 and it 'will be notedthat the buckets on wheel 15 are longer than those on wheel 14 and that the diaphragm nozzles flare radiallyoutward so as to direct the elastic fluid fromthe ringof buckets of smaller diameter to that of larger diameter.

According to my invention I provide the nozzle diphragm with nozzle partitions hav ing warped entrance edges, the edges being so warped that the nozzle walls are parallel tothe stream lines of the fluid. This requires that the angle which the entrance edge of each nozzle partition makes with the j axial change continuously throughout its radial depth as is best illustrated in Figs. 3-,

4 and 5. In Fig. 3, which is a section taken at the roots of the nozzle partitions, the entrance edges of the nozzle partitions are I axial, while in vFig. 5, which is a section taken at the tips of the nozzle partitions,,the entrance edges of the nozzle partitions extend at an angle to the axiaL, At intermedi ate'points, I entrance edges of thenozzle partitions ex;-

such as that shown in Fig. 4;, the I .9

5. The shape of the entrance ends of the nozzle partitions, i. e., the amount they need to be warped, dependsupon the bucket angle and speed, and the elastic fluid speed, and in Figs. 3, 4 and 5 I have shown vectordiagrams illustrating this. In these diagrams V A, A and A indicate the elastic fluid speed and direction relative to the bucket, these being approximately the same in each instance; B, B and B indicate the bucket ,speedwhich increases from the roots to the tips of the buckets,and C, Cand C indicate the resultant and show the direction of the elastic fluid flow from the buckets into the nozzles. As will be clear from Figs. 3, 4 and 5'th'e entrance ends of the nozzlepartitions are so shaped that they are at every point parallel to. the direction of elastic flow as represented by lines C, C and'C Bythis arrangement the nozzle partitions receive the elastic fluid Without shock and without the formation of objectionable eddies which disturb the flow and create losses. Also the arrangement eliminates the wearing away of the entrance edges of the nozzle partitions. Furthermore, the arrangement insures that the nozzles are properly filled with elastic fluid throughout their length. This latter is of particular importance in connection with flared nozzle passages of considerable height such as are required in the lowerzpressure stages of a turbine inorder to convey elastic fluid from a shorter bucket ring. to a longer one. By my invention the difficulties which have heretofore been experienced in properly filling such nozzles and the losses which. have occurred because of this are substantially eliminated. It has been found by experiments and tests that if a diaphragm having flared nozzles is provided with nozzle partitions having warped entrance ends in accordance with my invention, the nozzle passages including the fiared portions will be evenly and fully filled and there will be no disturbances or losses due to eddy currents.

I regard, therefore," the use of nozzle partitions having warped entrance edges in connection with diaphragms having flared nozzles as being an important feature of my invention.

WVhat I claim as new and desire to secure by Letters Patent of thelUnited States, is,-

1. A nozzle diaphragm for elastic' fluid turbines, characterized by the fact. that the entrance ends of the nozzle partitions are warped whereby elastic fluid discharged from the preceding bucket ring will enter.

the nozzles in stream lines parallel to the nozzle partitions.

2. A nozzle d'aphragm. for elastic fluid turbines characterized by the fact that the entrance angle or" the nozzle passages varies continuously throughout their radial-depth to such an extent that the elastic fluid will enter them in stream lines parallel to the entrance walls oi the nozzle partitions.

3. A nozzle diaphragm having nozzle partitions so shaped that the entrance angle to the nozzle passages varies continuously and in such manner that the elastic fluid will OSCAR JUNGGREN.