US814423A - Elastic-fluid turbine. - Google Patents

Description

ATENTED MAR. 6v', 1906.

G. BELLUZZO. ELASTIG FLUB TURBN'E.

APPLICATION FILED AUG. 24. 1905.

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Specification of Letters Patent.

Patented March 6, 1906.

Appinaion nea August zi, 1905. seria so. 275,559.

To 1r/ZZ 'uf/tom, it may concern:

soription of the invention, such as will enable I others skilled in the art to which it appertains to make and use the same.

My invention relates toimprovements in elastic-fluid turbines in which a plurality of bucket-Wheels is arranged to receive successively the jet or iluid yand in which the pressure of the Huid. is almost entirely converted into velocity by ex anding-nozzles before being delivered to t e buckets of the Wheels, while comparatively little expansion takes place in the wheels and inthe guiding members and my invention relates to turbines of this class in Wh ich the nozzle-sections are arranged about the entire periphery of the rotating mem bers orabout a part onlyof the SLIIIC.

'lhe object of my invention is to increase the eiliciency ot' turbines of this classby decreasing the loss resulting from sudden changes oll the diro :tion oll the jet of iiuid and at the same time by guiding the jet of fluid in a more perfect Way.

With this object in view my invention consists, first, in. constructing the sections of the nozzle and oil the successive guiding members with gradually-decreasing angles of delivery, whereby the jet of Huid is dischar ed into the successive bucket-Wheels at difierent angles and in Varying the height of the buckets and their distance from one another in the successive wheels, explained hereinafter.`

A second feature ol' my invention relates to turbinesin which thenozzle and the guiding members are arranged abouta'p'art only of the peripheryof the rotating members; and

my improvement?btisists in certain novel means to avoid the less occurring in each of the passages formed by the buckets of the rotating members whenever they leave the sphere ot' the nozzles or'oi" the guiding members and pass the cut-oll portions ofthe same.

A third feature oi my invention relates particularly to steam-turbines, and is desi ned to avoid th'edecrease of the efficiency o the machine resulting from the friction caused as will be more fullyby the preci itation of condensed steam on the inner wa is of the casing.

For the purpose of illustrating my inven tion I have shown an example of a turbine embodying my improvements in the accompanying drawings, in whichy Figure 1 is a partial section of my improved turbine parallel' to the axis oi the same, and Fig. 2 is a circumferential section of the same developed into a plane.

Similar letters of reference refer to similar parts throughout the different views.

In the present example I have illustrated a steam-turbine in which the nozzle and the guidingA members are arranged about a part -of the periphery of the rotating members' and in whic the flow of Huid is substantially parallel to the axis of the turbine. 'lhe said turbine comprises a stationary nozzle c and sectional stationary members c2, c3,- and e4, having steam-guiding members d2 di dJA and rotating members or wheels r 'r2 r3, provided with bucketsffzf, ate with said nozzles and guiding members.` The rotating members are mounted on a common shal't, as is usual in the art, and their number will, for practical purposes, vary from three to six, according to the ower to be developed by the turbine ant the speed at which it is designed to run. In the present instance, however, I show four rotating members and accordingly three guiding members apart from the nozzle. The nozzle c comprises two nozzle-sections d d', the walls of which diver e from the throat to the dis- 'charge end, W iereby the fluid is expanded almost entirely to the pressure oi the exhaust or of the condenser in case of a steamturbine, While verylittle expansion occurs in the succeeding guiding members. 'lhe nozzle c may be provided with a slide-valve p to regulate the amount ol' steam admitted to the turbine.

The guiding members d, di?, and d4 are provided With properly-shaped blades to receive the jets of steam discharged from the passages of the bucket-wheels and to direct them properly into the passages of the succeeding wheels. The buckets of each of the guiding members are of any preferred construction, with exception, however, oi the last one that will be explained hereinafter. The discharge ends of the blades of consecutive guidingmembers are arranged with diil'erent angles et delivery, said angles decreaslng from the arranged to cooper# IOO IIO

-largest one an steam inlet toward the outlet, whereby the 'ets ofthe steam are delivered to the buckets of the consecutive wheels ait decreasing angles to the'plane of the wheel, the angle of the jet dischar ed from the nozzle being the the line of travel of the wheel or the angle of inflow decreases from the steam-inlet, Where it is not'less than fty degrees toward the outlet. AI also manufacture the buckets of the consecutive wheels with decreasing width, which means in the case of ,a turbine with axial flow tlie'dimension of the buckets parallel to the axis of the turbine and which in the -accom anying drawings is designated by the letter Ihe width has its largest value in the first wheel and decreases radually toward the last one, where it shou d not be less than one inch and one-sixth. In turbines built-heretofore buckets have been used the height-of which was less than one inch and 'one-sixth. I have found, however, that the operation of such buckets is not satisfactory. Corresponding to the decrease of the width of my improved buckets and in the same V ratio I alsoidecrease the distance of the buckwheel r4 with a large number.

ets of the'different wheels from one another, whereby the wheel r/ is provided with a comparatively small number of buckets and the I have found that by varyin the angle of delivery into the bucket and t e width and the spacingof the buckets of the different wheels in the manner stated-above I-increasethe efficiency of the turbine by iin]- proving the travel of the fluid through the y uck'ets of the wheels and of the guiding members.

It is apparent that the improvements explained above with reference to a steam-turine, in which the nozzles are arranged about a part only of the periphery, will have the same beneficial results in turbines designed for the use :of anyother elastic fluid, as motive power, and in turbines in which the nozzle-sections are' arranged about the entire periphery. j

The second feature of my invention refers particularlyto turbine'siin which the nozzles are arran ed about a partl only of the periphery o the. wheels. I have discovered that in turbines of this class much loss results from the fact that the canals formedby the buckets of the wheels when they leave Vbeing -not smaller than fiftyV densedthe sphere of the 'Huid jets receive their last jet at a time when their outlet-passage'has just passed the cut-off edge of t' e next folf lbwing guiding member, whereby said jet cannot escape into the last canal of the following guiding member, and thereby impart its 'energy to the rotating wheel.- Now to avoid this disadvanta e I arrange the guiding members in suc way that the outlet-passages-of the bucket-wheels is still almost entirely open at the moment when its inlet-passage is cut off by the precedin guiding member or nozzle, and to effect t is I curve the wall of the guiding members that forms the cut-off. edge backward, so as to register with the discharge portion of the receding bucket when the inlet portion ofi the succeeding bucket just passes the'cut-offedge of the, rec I ceding guiding member. The said wal of said guiding members will therefore have a strongly-curved form, as shown at a bin Fig. 2 of tne drawings. In cooperation herewith it will generally be necessary to cut olf a part Y of the last blade of the guiding members at itsdischarge end in order to secure a free and unobstructed passage for thedischarged fluid. l It is apparent that the aforesaid improvement is applied only to the guiding members and not to the nozzle-sections. I AThe third feature of myinvention refers particularly to steam-turbines, and its purpose is to avoid the 'precipitation' ofy consteam on the inner. walls of the casing, which condensed steam would offer considerable resistance to the blades. For this purpose I provide the members c2, 03 and c4 with ajacket havinga steam inlet and outlet. Now preferably some time before'startin. the turbine Iadmit steam to said jacket an heat the turbine, whereby condensation of steam is avoided. 1

The operation of -my improved yturbines will be readily understood from the description of its parts. It doesrnotvary in any respect, save efliciency, from turbines heretofore in use. v v

Having thus fully described myinvention, what I claim as new, and desire-to secure by Letters Patent of the United States, is

1. In elastic-fluid turbines, Vthe combination with a nozzle, -of a plurality of. bucketwheels arranged successively to receive the motive fluid, the angles of delivery-into the bucket-wheels and the angles ofthe inlet ortions of the buckets of the several buc etwheels 'to the line of travel of said wheels being arranged to decrease from the nozzle side toward the exhaust side of the turbine.

2. In elastic-fluid turbines, the combina- 1 tion with an expanding-nozzle arr-an ed to convert the pressure of the fluid into ve ocity, of a plurality 'of bucket-wheels arranged successively to receive the motive fluid, the angles of delivery into the bucket-wheels and' the angles of the inlet portions of the buckets 1o :fluid-guiding members,

r 5 bucket-Wheels zo tion, with ane golet ,portions to their 5 the motive fluid, t

of the several bucket-Wheels to the line of travel of said wheels being arranged to decrease from the nozzle side toward the exhaust side ofthe turbine. q 3. In elastic-fluid turbines, the combination, With an expanding-nozzle arranged to 'convert the pressure of the fluid into velocity, of a plurality of bucket-Wheels arranged successively to receive the motive Huid, and

said-nozzle and guiding members having their angles of delivery into the bucket-Wheels arranged to decrease successively from the nozzle to the last' of the guiding members, and thebuckets of "said having the angles of their inlet portions to their lineof travel arranged to decrease from the nozzle side toward the exhaust side of th'e turbine.

` 4. In elastic-,Huid turbines, the combinaxpanding-nozzle arranged to convert the pressure of the fluid into velocity. of a plurality of bucket-Wheels, and fluidguiding members, said nozzle 'and guiding members having their angles of delivery into 2 5 the bucket-Wheels arrangedto decrease successively from a' value of substantiallyrfty degrees in the nozzle to the last one of the uiding members, and the buckets of Vsaid ucket-Wheels having the angles of their inline 'of travel arranged to decrease from the nozzle sidetoward the exhaust side of the turbine. 5. In an elastic-Huid turbine, the combination, with a nozzle, of a. plurality of bucket- 5 'Wheels and fluid-guiding members arranged to receive successively the motive fluid, the buckets of.'consecutive Wheelshaving their Width decreasing'fr'om the inlet side to the exhaust side of the turbine.

,o 6. In an elastic-fluid turbine, the combination, with anexpanding-n-ozzle arranged to f convert the pressure of the fluid into velocity,

of a phrali ty of bucket-Wheels and Huid-guiding members arran ed to receive successively e buckets otconsecutive Wheels having their width decreasing from lghe inlet side to the exhaust side of the turine.

. 7. In an elastic-fluid turbine, the combinaa tion, with a nozzle, cfa plurality of bucket- Wheels, and fluid-guiding members arranged to receive successlvely the motive Huid, thev buckets of consecutive Wheels havingv their Width and their distance from one another decreasing from the inlet side to the exhaust side of the turbine. 8. In an elastic-Huid turbine, the combination, with an expanding-nozzle arran ed to convert the pressure of the Huid into veIocity, of a plurality of bucket-Wheels, and fluid- Yguiding members arranged to receive succestion, With an expanding-nozzle arranged to convert `the press re of the fluid intovelocity, of a plurality of bucket-Wheels and fluidgui'dmg members arranged to receive successively the motive iluid, t-he buckets of consecutive Wheels having their width and their distance from one another decreasing vfrom the inlet side to the exhaust side of the turbine, the width of the buckets of the last Wheel being not less than one inch and onesixth.

10. In an elastic-fluid turbine, the combi- I nation, With an expanding-nozzle arranged to convert the lpressure of the fluid into velocity, of a plurality of bucket-Wheels, and fluid-guiding members arranged to receive successively the motive Huid, Ythe buckets o1 consecutive Wheels their distance from one another decreasing .substantially in thev same ratio from the inlet side toward the exhaust side of the turbine.

11. In an elastic-fluid turbine, the combination, with a plurality of bucket-Wheels, of anozzle, and a Huid-guiding member arranged about a part of the periphery or said bucket- Wheels, said guiding member having guidingblades and having its cut-ofi wall curved backward in the direction of the travel ofthe 9 rotating member discharging into the same at an angle smaller than that of said guidingblades to such an extent that the outlet of each of the passages of said rotating member is still open When its inlet is cut ofi.

12. In an elastic-Huid turbine, the combi- -nation, With a plurality of bucket-Wheels, of

a nozzle, and l a fluid -guiding member arranged about a part of the periphery of said bucket-Wheel, said guiding member having guiding-blades and having its cut-ofi Wall curved backward in the direction of the travel of the rotating member discharging into the same at such an extent that the outlet of each of the passages'of said rotating member is stili openWhen its inlet is cut oil", the last of said blades of the guiding members having a part of its discharge end cut away.

In testimony whereof I aflix my signature to this specification in the presence of two witnesses. I

` GIUSEPPE BELLUZZO. v Witnesses:

MIoHELo DE DRAGO, BLARTo SaLvATTI.

having their width and- IOO

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