US916968A - Nozzle for elastic-fluid turbines. - Google Patents

Description

H. s. BALDWIN.

NOZZLE FOR ELASTIC FLUID TURBINES.

APPLIUATIGN FILED MAY 28, 1907.

PatentedAp1z6,l909.

2 SHEETS8HEET 1.

v Witnesses H. S. BALDWlN.

NOZZLE FORELASTIG FLUID TUBBINES.

APPLIGATION TILED MAY 28, 1907.

Irwvanhcafi Saldwia FEE-iv 2 SHEETS-SHEET 2.

9 Q 9 1 A 6 v D A d e t n m a P hcation.

cross section.

t i his? BALDWIN,

N'QZZL'E FOB ELAS'LBlG-JELUID TURBENES;

Ho. ELI-553i,

Application filed May 23,

Specification 0t Letters Patent.

renamesra e, teen.

To allwliom-ii nary concern:

it known that l, Haney a citizen of the lnnteol L-ltates, i! I" 1 no, county 0 setts, have lllYBlltQtl certain new and uselul niorovenicnts iniiozzles tor Elastic-Fluid w l I. t ics, or which the following is a speci- S. lliLnwiin TGSltllIlg. at

.turhn With turbines as ordinarily constructed the nozzles are the most expensive and diflicult parts to make, owing to the exacting requirements. This due chiefly to the tact that the passages have to he of peculiar shape and no one tool is ozuyalole of properly 'loriniing them. As a result there is a great deal of hard work necessary, and it is exceedingly ditiicult to form two nozzle passages which are absolutely alike in every particular. This particularly true where the throat is round or oval in cross'section, and the discharge portion rectangular in The ditiiculty in properly forming assages further increased in those nozzles there there is a certain. expansion or increase in the size of the nozzle passage from the throat to the discharge end.

lvlyflinvention has for its object to over come the objections above set forth, and to provide a. nozzle and nozzle s1 pport of iniproved construction.

My invention further has for its object to improve the manufacture of these nozzles hy n drop forging process.

in the accon'ipanying drawings which illustrate one of the embodiments of my invention, Figure l is a partial axial section of a turbine, the section of the nozzle being taken on line l -l ot Fig. 2; F g. 2 1s a view oi? the nozzles and the supporting plate viewed from the discharge side; 1* 1g. 3 is a section taken on line 3-45 of Fig. 3', Fig. l is a perspective riow or a iinished nozzle; his". 5 is a view in elevation of a drop-forged nozzle blank; Fig. 6 is a partial plan View of the same; Fi 7 is a longitudinalscction of the blank after it has been l'titifilll)t)l'0tl; Fig. 5 is a cross-section ol the hlanlt taken on the line S--8 of Fig. 5; l igr. 9 is a longitudinal View of tho-blunt; after it has'bcen reamed, Fig. 10 is a View showing the means for forming; the throat of the nozzle; Fip. 1.1 is a longitudii'ial section ol. the nozz e blank alter the discharge portion has been shaped in dies; Fig, 12' is a View of the nozzx, State of Massachu-- zle atter the discl'iarge end has-been out oft at the proper angleg-l i f, i5 is section taken on line 13l.3 of Fig. 11; Figfll is a' section taken on line Mk 1% of Fig 11; 1.5 is a section taken on line Tt5-15 of Fig. ill; Fig. 16 is an inverted plan view of the tinishcd nozzle.

Iltclerring to 1g. 1, 1 indicates a steamchest hating a urality of passages 2 which supply steam 0. other elastic fluid to the. nozzle bowls. lhe nozzlesnre supported by a plate 3 which is bolted or otherwise secured to the under side or" the'valvo chest. The chest itself is supp rt-ed' by the head at; the latter resting upon the heel casing 5. Mounted within the casing are Wheels 6., of which one is shown. 0n the periphery of the wheel are rows of buckets 7 and hetwcen the rows of buckets are intermediates 8. After the steam leaves the first Wheel it passes through stage nozzles 9 to the wheel or" the second stage, and so on. The stage nozzles are carried by the diaphragm 19, which divides the chernher Within the easing into wheel compartment-s, The nozzles are counterparts. in the construction so that a description of one otthern will sufiice.

Referring to Fig. 4- showing a finished nozzle, 11 indicatesth'e cylindrical portion. or head containing the bowl 12, Fig. 3. have shown this portion as being cylindrical the main "feature being to provide a head the exterior of-which will act as a support for the nozzle when it is mounted 111 the nozzle plate and preventthe sonic from moving toward or away from the wheel buckets. The cylindrical portion or head is cutaway on one side at an incline as shown at 1; in Fig. i, the object being to permit the separate nozzles to be closely 215-. sociated as shown in Figs. 2 and 3, so that the steam-therefrom will issue as a solid jet or column, and further, thatthe angle of discharge of every nozzle will be the correct one and the same as that of every other. The shoulder thus formed on the under side of the head is also utilized as a part oi the rule-ans for holding the adjacent nozzle in n ace.

Extending from the head is a stem or a ing of the enpanding type, but it is quite evident that it may be of the non-expanding type if it will satisfy the conditions of operation in the turbine. provided with as many orifices 15 as -there are nozzles. Each of these orificesis of such shape that it will receive the head 11 of the nozzle and form a supporttherefor throughout its length. The openlngsare chanifered slightly, as at 16, so that when the metal forming the finished head is expanded, the nozzle will be firmly secured in place. In order to nest the nozzles closely, it is necessary to remove a certainamount 15 of the metal between the openings 15, and

in the same circumferential plane as indicated at 17. When the nozzles are in. place the discharge portions or stems extend through the slots 17, and the Walls o; the same engage the sides of the discharge portions and prevent the same from turning in the orifices 15.

Referring to Figs. 5 to 16, the method of forming the nozzles will be described. The blank to form the nozzle iss'made by the drop-forging process and from some suitable material, such, for erample, assteel,

nickelsteel, Tobin bronze, or the like. blanks are drop-forged to exact dimensions and of desired outside shape. Bymaking the blanks in this manner, be cheaply constructed and made to exact dimensions and will also be counterparts. It is also possible to use one die or set of time for several diflerent kinds of nozzles which differ from'each other only in a slight degree. 'After the blank is completed as shown in Fig. 5, which may be done by one, two or moreoperations, it is 40 bored at 18 to form the discharge passage and the head at 19 to form the bowl, sulficient metal. being left to provide for finishing. The next operation is to ream out the stem or discharge portion by a reamer of such. size-and construction as will provide the exact cross-section of nozzle area de sired at every point. The bowl is then milled out byjneans of a rose mill. The

next step is or may beto mill out the throat between the bowl and the discharge portion, which results in the construction shown in Fig. 10. In this figure 20 represents the mill for cutting away the metal to form the ski/throat 21. If a rectangular delivery sec? tion is required in order to lessen the height of the wheel buckets and at the same time cause them to be filled with steam, the outlet end of the nozzle may be pressed cold into the desired shape, as shown in Figs. 11 to 14, the throat section being shown in Fig. 15. In order to accurately form the nozzles at this stage of manufacture, a mandrel or former of suitable shape is provided which is inserted in the discharge portion either at The nozzle plate is- The the nozzles canplaced in a suitable jig and the stem roughand practically nothing. is left to the skill of .quantities and apply them to machines as ethe beginning of the operation or prior to final finishing.v The next operation is to place the nozzles in a circular jig in the same relative position which they will oc-' cupy when in the turbine-and face off the lower end as shown in Fig. 12. In this case the discharge angle is 20. Instead of milling out the bowl after the reaming operation I may reserve this until after the ress- 4 ing operation or until after the en 'has been beveled, as shown in Fig. 12. -The advantage in milling the throat after the pressing operation resides in -the fact that there is a little more metal left at the throat to resist the strains to which the nozzle is so subjected in changing its form from a round to a rectangular section. .At the time the nozzle is giventhe rectangular discharge section, it is also curved as shown in Fig. 16, so that the opposed walls 22 and 23 are concentric with the axis of the turbine Refen-lug to Fig, 2, the last nozzle m the group, consi erin the direction of rotation of the wh is vrat mounted in place and j the wall of the bowl expanded or stakeld over the chamfered men of the nozze plate, then the secon nozzle is mounted in place and so on until they are all in place.

he nozzle plate is subsequently bolted to the valve chest or other support. a,

Nozzles made in accordance with my improved process of manufacture are much superior to those constructed heretofore with which I am familiar. By drop-forgiir the blanks the metal forming the walls of the nozzle wil be homo neous'and therefore free from irregularities in structure which would cause one part to wear more rapidly than 'anotherl' B reaming the parts as described, each wil be exactly to dimensions the workman. By making the stem and head integral all j oints to be acted upon by the motive fluid are obviated. Further, the surface of the parts sub'ected to the action of the fluid will be bar and smooth, thereby reducing losses to a minimum. The nozzles will be exact counterparts, and such being the case, it is possible to make them in lar e sired. They can a o be shipped as supply f parts with the certainty that they will fit the machine for which they are intended and 3' also be like those already in use. v

The nozzles can be made in a variety of sizes to suit the requirements, andcan be used between stages as wellas for'the purpose of admission. They may be used for axial-flow machines, as shown, or for-tan: gential or radial flow as desired. 1

By actual comparison I have found that nozzles made in accordance with my inyention are much cheaper to manufacture than those heretofore made by the casting and. hand processes.

ios

memes In accordance with the rovisions of the patent statutes have described the principle of operation of my invention, together with the apparatus which I now consider to represent the best embodiment thereof; but I desire to have it understood that the apparatus shown is only illustrative and that the invention can be carried out by other means.

Yi'hat I claim as new and desire to secure by Letters Patent of the United States, is,

i. In an elastic-fluid turbine, the combination ot a support containing a plurality of cylii'ithieal orifices with connecting slots and d i'op forged nozzles carried thereby, the heads of which. are cylindrical and make a snug fit with the walls of the orifices and are cut away on the under side and overlapping stems which pass through the slots in the support and also through the cut-away portions of the heads.

2 It drop-forged nozzle for an elasticfiuid turbine comprising a head which has straight sides for holding the nozzle in its support, is cut away on-a bevel on one side of its under side to receive the stem of the adjacent nozzle when mounted in place and is cut away internally to form a bowl, and a stem which is made integral with the head and contains a bore that communicates With the bowl.

In witness Wl1GI80f,,I have hereunto set my hand this twenty-fifth day of May, 1907. HENRY S. BALDX VIN. Witnesses JOHN A. MoMANUs, J12, PHILIP F. HARRINGTON.

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