US1003321A - Steam-turbine. - Google Patents

Description

G. BELLUZZO.

STEAM TURBINE.

APPLICATION FILED JAN. 27, 1909.

Patented Sept. 12, 1911-.

4 SHEBTS-SHEET 1.

nbrlnl COLUMBIA PLANOORAPH CO., WASHINGTON, D. c.

G. BELLUZZO.

STEAM TURBINE.

APPLICATION FILED JAN. 27, 1909.

1,003,321 v Patented Sept. 12, 1911 4 SHEETS-SHEET 2.

q I [I I FmMamzw/V mmll COLUMBIA PLANODRAPM c0.. WASHINGTON. D. c.

G. BELLUZZO.

V STEAM TURBINE.

APPLICATION FILED JAN. 27. 1909.

Patented Sept. 12, 1911.

4 SHEBTS-SHEET 3.

' COLUMBIA PLANOGRAPH cO.,wAsHlNOToN. D. c.

G. BELLUZZO.

- STEAM TURBINE.

APPLICATION FILED JAN. 27, 1909.

Y 1,003,32L Patented Sept. 12, 1911.

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w) (WM (M ml (mm (m UNITED STATES PATENT OFFICE.

GIUSEPPE BELLUZZO, OF MILAN, ITALY.

STEAM-TURBINE.

To all whom it may concern:

Be it known that I, GIUSEPPE. BELLUZZO, mechanical. engineer, subject of the King of Italy, residing at No. 1 Via Paolo Frisi, Milan, in the Kingdom of Italy, have invented new and useful Improvements in Steam-Turbines, of which the following is a specification.

This invention relates to steam turbines. lVhile applicable to all descriptions of turbines, it is particularly intended for turbines having a slight degree of reaction, or for impulse turbines with multiple expansion and running wheels in series or even for a combination of these types.

In the accompanying drawings showing constructions embodying my invention Figure 1 represents in vertical longitudinal central section the admission part of such a turbine; Fig. 2 a sectional detail-view in longitudinal section, taken on a different plane from Fig. 1; Fig. 3 a longitudinal vertical central section on a reduced scale, of the upper half of the entire turbine; Figs. 4, 5 and 6 similar views of modified forms of turbines under the invention; Fig. 7 a similar view of the turbine represented in Fig. 6, when arranged for forward running; Fig. 8 a similar view showing balance thrust arrangement applied to the admission and exit part of the turbine; and Fig. 9 a diagram showing a form of arrangement of the vanes under the invention.

In the constructions shown, the partition walls between adjacent wheels are dispensed with and the admission of motive fluid takes place on the entire periphery of the wheels.

Referring to Figs. 8 and 6 it will be observed that the high pressure part of the turbine consists of one or two groups of wheels marked 1 and 2, in which the steam chiefly expands in the first set of vanes. The speed of this steam may attain 600 meters on leaving the first group and 500 meters on leaving the second group, which amounts to saying that the ratio between the greatest and the smallest section of the vanes'in the first group is greater than that in the second group. The intermediate pressure portion of the turbine is occupied by a number of wheels marked 3 and 4 in the drawing (Fig. 3), said wheels being multiple expansion impulse wheels, or wheels with a slight degree of reaction. Be-

Specification of Letters Patent. Patented Sept. 12, 1911. Application filed January 2'7, 1909.

Serial No. 474,629.

tween the vanes of these wheels the steam flows with a constant speed of about 400 meters. The diameter of these wheels is the same or greater than that of the high pressure wheels or rings. The low pressure or outlet part of the turbine receives the steam on the entire periphery of the drum marked 5, whose multiple expansion wheels have the same or even a greater diameter than that of the wheels in the intermediate pressure portion of the turbine. These wheels may be either of the impulse, small reaction or middle reaction type. The steam within the vanes of the same has a lower velocity than in the intermediate pressure part. Under all circumstances, in view of the decrease of the speed of outflow of the steam from the vanes which takes place in passing from the high pressure to the low pressure end of the turbine, the angles of inlet of steam into the intermediate sets of vanes of each group, gradually increase in the direction toward the exhaust. This arrangement of the vanes is shown diagrammatically in Fig. 9. From an inspection of this figure it will be seen that the angle a bet-ween the direction of admission of fluid between the vanes of the intermediate wheel 1 of the first group and the plane of the wheel is less than the angle 6 between the direction of admission to the intermediate wheel 2 of the second group and the plane of the wheel and that in turn this angle is less than the angles 0 and d of the subsequent groups, the angle d between the direction of admission to the intermediate wheel 4 of the last group and the plane of said wheel being the greatest. In other words the angle of admission of fluid to the spaces between the vanes of the wheels increases progressively from each group to the succeeding one in the general direction of the flow of the fluid or in other words, from the admission part to the exhaust part of the turbine.

When working with a small degree of reaction, two different pressures are exerted upon the opposite faces of each wheel, even where partition walls are inserted between each wheel and the adjacent one. If, according to the usual construction, the wheels in the low pressure part of the turbine are mounted on a ring or a drum, as shown in Figs. 3, 4 and 5, said drum or disk is subject to a considerable axial thrust, whether the wheels be impulse or reaction wheels. In Fig. 3, for example, the pressure within chamber N is higher than that in the chamber O on the opposite side of the web of the drum supporting group 5 of wheels. Thereby an axial thrust on said drum to the right is created. It is one of the purposes of this invention to balance this thrust. The arrangement for this purpose is shown in Fig. 3 and, on a larger scale, in Fig. 1. This arrangement is as follows: To the disk D, supporting the group 1, of first high pressure wheels, there is fitted another, smaller disk d, provided with a flange between which and a shoulder on the cover V of the turbine casing is arranged a labyrinth L which provides a steam-tight closure for the chamber C formed betweenthe disk d and the cover V, which chamber communicates with a chamber 0 formed bet-ween disk cl and disk D. In these chambers G and 0 there reigns a lower pressure than that existing in the chamber B on the other side of the disk I). For this purpose I may connect the chamber 0 with the chamber N as best shown in Fig. 8. Thus a considerable difference of pres sure will be caused to exist on the opposite sides of disk D, giving rise to an axial thrusttoward the left which will almost exactly balance the aforesaid thrust to the right, provided the diameter of disk cl be properly chosen. The same object, tho-ugh with larger losses of steam, depending upon the leakage, may be attained by applying the labyrinth L7 to the exhaust chamber 0, as in Fig. 4, and arranging an opening n, as shown be tween the chambers N and O. Thereby steam of a much higher pressure than the condenser pressure is introduced into the chamber, 0.

In the modification shown in Fig. 5, a thrustcompensating chamber G corresponding to the chamber C in Fig. 1 is provided in the exhaust portion of the turbine, and also a labyrinth packing L to close off the chamber C against the exhaust chamber 0, said labyrinth packing being in this case of a much smaller diameter than that of labyrinth L or labyrinth L (Figs. land 4.), in which latter case said diameter is substantially equal to that of the low pressure drum W. Into the chamber 0 steam at a pressure exceeding the condenser pressure is, for instance steam coming either from chamber M or N, Fig. 3, admitted as indicated in said Fig. 5.

In order to decrease the diameter of disk 03, Figs. 1 and 3, chambers C and C closed off against the extreme pressure chambers by a labyrinth packing may be applied both at the admission end and the exhaust portion of the turbine casing. This arrangement is shown'in Fig. 8, from which it will be seen that under such construction the pressure fluid from the middle pressure portion N of the apparatus is led into the chambers C and C" by a pipe N.

As shown in Fig. l, the partition, P, is provided wit-h a recess I facing the exhaust of the wheels and deflecting the steam toward the axis of the turbine, while on the admission side of each of the following groups of wheels the steam is admitted through an inlet as shown in Fig. 2, which is a section on a different plane from that on which the section of Fig. l is taken. Thereby the exhaust of any of the wheels of a group is prevented from in any way interfering with the inlet parts of a following wheel.

The type of turbine hereinbefore described may be applied to the propulsion of vessels, in which case the first groups of wheels 1 and 2 (Fig. 6) are preferably provided with double curvature vanes for reversing the motion, the steam being alternately admitted either to the set of vanes designed for the forward or to the set intended for the backward motion by substantially the same means as described in my application dated June 18, 1906, and numbered 322,336. This arrangement is illustrated in the diagram, Fig. 9. During the backward running of the ship the steam, which has impinged against the double curvature vanes in a direction opposite to that corresponding to the forward motion exhausts into a chamber A, which by means of a tube a ending at port a,, is put in communication with the guide vanes of other wheels controlling the backward motion situated near the exhaust and discharging into the condenser. During the forward running of the ship the port (1., is shut, and the steam takes the course indicated in Fig. 7, which shows the turbine arranged for forward running.

By referring to Figs. 1 and 5, it will be noted that disk (Z at the admission end, and the disk d, at the exhaust end of the turbine may be provided with an annular recess a, which is designed to receive counter-weights whose purpose it is to balance or equalize the rotary portion of the turbine, dynamically and statically considered. As shown in Fig. 8 such recess may be provided in only one of the disks d or (1.

Instead of impulse wheels for the middle pressure group of wheels, slight reaction wheels may be employed and the two are to be considered the equivalents of each other for the purposes of this invention.

hat I' claim and desire to secure by Letters Patent is 1. In a multiple expansion turbine, a series of groups of wheels provided with vanes, the aggregate space between the vanes of each succeeding group bearing a ratio to the diameter of the wheels which increases in proceeding from the admission to the exhaust portion of the turbine, whereby the ratio between the fluid-flow speed and the peripheral speed of the wheels decreases as the pressure of the fluid decreases.

2. In a multiple expansion turbine com prising a high pressure, a middle pressure, and a low pressure group of wheels provided with peripheral vanes, the combination, of a high pressure group of wheels, partial admission means for said group, a middle pressure group consisting of impulse wheels adapted to be operated by the pressure of the fluid, and a low pressure group of impulse wheels, and means for total admission of steam thereto, the angles of admission of fluid to the spaces between the vanes of said wheels increasing progressively from each group to the succeeding one from the admission part to the exhaust part of the turbine.

3. In a multiple expansion turbine com prising a high pressure, a middle pressure, and a low pressure group of wheels provided with peripheral vanes, the combination, of a drum carrying vanes at one end of the turbine casing, two chambers arranged on opposite sides of the drum web, a communication between said chambers and a labyrinth packing for closing of]? the chamber at the extreme portion of the turbine from the extreme fluid pressure, means for causing one of said chambers to communicate with the middle fluid pressure portion of the turbine, whereby the axial thrust on the drum is balanced.

4. In a multiple expansion turbine, comprising a high pressure, a middle pressure and a low pressure group of wheels provided with peripheral vanes, the combination, of a drum carrying vanes at one end of the turbine casing, chambers for the middle fluid pressure and for the low pressure, and another supplemental chamber at the extreme portion of the turbine casing, said chambers being arranged on opposite sides of the drum web, communicating means between the supplemental chamber and the middle fluid pressure chamber, and a laby rinth packing for closing off the supplemental chamber from the low pressure chamber of the turbine, whereby the axial thrust on the drum is balanced.

5. In a multiple expansion turbine, comprising a high pressure, a middle pressure and a low pressure group of wheels provided with peripheral vanes, the combination, of a drum carrying vanes at one end of the turbine casing, chambers for the middle fluid pressure and for the low pressure, and another supplemental chamber at the admission portion of the turbine casing, said chambers being arranged on opposite sides of the drum web, communicating means between the supplemental chamber and the middle fluid pressure chamber, and a labyrinth packing for closing off the supplemental chamber from the low pressure chamber of the turbine, whereby the axial thrust on the drum is balanced.

6. In a multiple expansion turbine, comprising a high pressure, a middle pressure and a low pressure group of wheels provided with peripheral vanes, and high pressure, middle pressure and low pressure chambers, the combination, with the casing, of drums carrying vanes at the admission and at the exhaust portion of the turbine, of a supplemental chamber at the admission and the exhaust portion of the turbine, each arranged on the outside of the web of the respective drums, labyrinth paokings for closing oit the said chambers against the fluid of admission and the fluid of exhaust, and means for causing said supplemental chambers to communicate with the middle pressure chamber, whereby the axial thrust on the drums is balanced.

7. In a fluid pressure turbine, a high pressure admission chamber, a drum carrying vanes arranged within the same and a partition wall closing off said chamber against the succeeding chambers, said partition wall being provided with a deflecting recess opposite the upper periphery of the drum and adapted to deflect the pressure fluid coming from the vanes toward the axis of the turbine, a group of lower pressure vanes arranged adjacent to the admission chamber, and an inlet port leading from a point near the turbine axis through vanes on the drum through the partition wall to the group of lower pressure vanes.

In testimony whereof I hereunto alfix my signature in the presence of two witnesses.

GIUSEPPE BELLUZZO.

Witnesses MICHAEL SIENDOCFER, Jr., It. CARLO SALvo'rIE.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents.

Washington, D. C.

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