US969821A - Reentrant turbine. - Google Patents

Description

G. WESTINGHOUSE.

REENTRANT TURBINE.

APPLICATION FILED FEB. 26, 1909.

Patgnted Sept. 13, 1910.

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WITNESSES:

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Patented Sept. 13, 1910.

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G. WESTINGHOUSE. RBENTRANT TURBINE.

APPLICATION FILED FEB. 26, 1909.

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GEORGE WESTINGHOUSE, OF PITTSBURG, PENNSYLVANIA.

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Specification of Letters latent.

Patented Sept. 13, 1910.

Application filed February 26, 1909. Serial No. 480,295.

To all whom it may concern:

Be it known that I, GEORGE WESTING- HOUSE, a citizen of the United States, and a resident of Pittsburg, in the county of Allegheny and State of Pennsylvania, have made a new and useful Invention in Reentrant Turbines, of which the following is a specification.

This invention relates to elastic fluid turbines and more particularly to turbines of the re'ntrant type.

In the drawings, Figure 1 is a view in sectional elevation of the upper half of a turbine embodying this invention; Fig. 2 is a developed section showing the lay-out for the several'expansion stages; Fig. 3 is a detail view of a portion of the turbine illustrated in Fig. l; and, Figs. 4, 5, 6and 7 are views of modified forms of the turbine illustrated in Fig. 1.

The turbine consists of a rotor or wheel 8 mounted upon a shaft 9 which is journaled within suitable bearings 10. The shaft passes through suitable stuffing boxes or glands 11 carried by the casing 12 which is circumferentially split into two portions and bolted together at 13. The portion 14 of the casing contains the initial inlet 15 of the turbine and the exhaust 16. This portion also carries the collectin chambers 17, 18, 19 and 20 for the third, fi th, seventh and ninth expansion stages, while the portion 14 of the casing contains the collectin chambers 21, 22, 23, 24 and 25 for the secon fourth, sixth, eighth and tenth expansion stages.

The rotor element carries a single row of impulse blades 26 which are preferably dropforged and rovided with shroud portions 27, which w en machined, form a practically continuous smooth shroud. The outer periphery of the rotor on each side of the row of blades is machined and segmental nozzle members 28, which together form a ring, have their inner peripheral surfaces 29 machined so as to lie in close proximity with the outer periphery of the rotor.

The two sectlons of the casing are machined so as to provide a shouldered recess 30 and each of the sections 28 forming the nozzle ring is provided with flanges 31 which are held against the shoulders of the recess 30 by means of steam pressure bled into the recess 30 through a restricted port 32 from one of the lower stages of expansion.

The nozzle sections 28 are grooved at 33 to receive sectional packing strips 34 which lie within the groove and are fluid pressure pressed toward the shroud of the blades.

The grooves 33 are provided with ofi'set shoulders 35 which limit the movement of the packing pieces toward the shroud. Blocks 36 screwed or otherwise secured to the casing are provided with fluid pressure pressed packing stri s 37 corresponding to strips 34 which yiel ingly bear against the side faces of the rotorelement and revent leakage of steam to the interior of t e casing. These packing strips are limited in their movement toward the wheel by means of shoulders 38 formed for that purpose in the blocks 36.

The interior of the casing or that part lying within the inner packing ring 37 may be connected to the condenser or to atmosphere, or if desired, to one of the stages of expansion, inorder to maintain a predetermined pressure within the casing to minimize leakage from stage to stage.

In Fig. 4 the packing rings 34 are carried in a two-part stationary member 28 which is rigidly secured within the casing. In this modification the sides of the wheel or rotor are reduced and thepacking strips 37 bear against the reduced portion of the wheel. In the modification shown in Fig. 5 the blade shrouds are preferably machined into the channel section as shown at 27 and yielding packing strips 34 bear against the sides of the shroud. In this modification also the packing strips 37 are supplanted by a sin le packing strlp 37 provlded with a broatl grooved face 10 whlch lies in close proximlty to the reduced portion of the rotor. I

In the modification shown in Fig. 6, packing rings 37 are used in combination with the packings 34.? bearing against the sides of the shroud.

In'the modification shown in Fig. 7, packings 37 are used in combination with a single yielding packing strip 41 which is preferably of the same width as the shroud.

In accordance with the provisions of the patent statutes, I 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.

What I claim is: V

1. In an elastic fluid turbine, a rotor element provided with shrouded blades, a casing, fluid discharge devices carried by said casingand forming with said rotor element, rentrant stages and yielding fluid pressed packing means for minimiz ng the escape of working fluid radially outward and inward from said blades.

2. In an elastic fluid turbine, a rotor element provided with a row of shrouded blades, a casing surrounding said element, fluid discharge devices forming with said element, rentrant stages extending circumferentially of said turbine, yieldingly mounted packing strips located above and below the Working faces of said blades for minimizing the escape of working fluid from stage to stage, and means for limiting the movement of said strips toward said element.

In testimony whereof, I have hereunto subscribed my name this 16th day of February, 1909.

GEO. WESTINGHOUSE. \Vitnesses:

CHARLES W. MoGHaE, JNO. S. GREEN.

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