US1740372A - Elastic-fluid turbine - Google Patents

Description

Dec. 17, 1929. o. ROSENLOCHER I ELASTIC FLUID TURBINE Filed April 17, 1928 m E v a Patented Dec. 1'7, i929 LINE? OTTO ROSENLQCHER, 0F BEE-LIN, GERMANY, ASSIGNOR TO GENERAL ELECTRIC COM- PANY, A COBPQRATION OF NEW YORK ELASTIC-FLUiD TURBINE Application filed April 17, 1928, Serial No. 270,762, and in Germany May 2, 1927.

The present invention relates to elasticfluid turbines, and more particularly to an improved construction in such turbines "for reducing losses represented by the flow of leakage elastic fluid through. and about the rotating or moving parts thereof.

As is well known and understood, leakage elastic fluid continually dissociates itselr" from the main stream in the working passage of an elastic-fluid turbine through the leakage spaces communicating with the working passage and circulates about the moving parts without becoming eiiective, later rejoining the main stream at some point in ad vance of that at which it left as regards the flow of elastic fluid through the turbine. ln rejoining the main stream, the leakage fluid passes through the leakage spaces communicating directly with the main or working passage and impinges upon the main stream at substantially a ri ht angle thereto.

In leaving and rejoining the main stream throughout the length of the working passage, the leakage elastic fluid sets up whirls and disturbances in the main stream which represent a considerable loss in eiiiciency in addition to that occasioned by the circulation of the leakage elastic fluid about the moving parts.

It is therefore the object of the present invention to provide in an elastic-fluid turbine an improved construction whereby the losses occasioned by the leakage elastic fluid are materially reduced and disturbances in the main elastic fluid stream thereby are prevented.

According to the invention, losses and disturbances of the above-named type are prevented by providing openings or passages in the supporting structure for the fluid directing means and moving bucket means or in the stationary and moving parts associated therewith, to connect the clearance spaces and provide a free passage or passages extending in the direction of fluid flow or paralleling the working passage in such a manner that a union of the leakage fluid with the main fluid stream in the working passage is prevented.

For a further consideration of what is believed to be novel and the invention, attention is now directed to the accompanying drawing, the description taken in connection there with, and the appended claims.

In the drawing, Fig. 1 is a sectional View showing a portion of a working passage in an ordinary drum reaction type axial flow turbine arranged in accordance with and embodying the invention, and Figs. 2 and 3 are detail views on an enlarged scale in transverse and longitudinal section-respectively of a bucket spacing means therefor.

Referring to Fig. 1, 5 is a turbine casing or stator carrying spaced rows of radial fluid directing blades 6, and 7 are rows of radial buckets or blades which operate between the rows of fluid directing blades and which are carried by a drum or rotor 8. Between the alternate rows of blades and buckets are provided the usual radial clearance spaces 9. Between the ends of the buckets or periphcries of the bucket rows and the interior of casing 5 are indicated the longitudinal running clearance spaces 10 which are reduced in area by bafiies or ribs 11 carried by the outer peripheries of the bucket rings. Similar clearance spaces 12 are provided between the ends of the fluid directing blade rings and the rotor 8, which are reduced in area by ribs 13 carried at the inner peripheries of the blade rings.

The working passage construction, above described, represents any suitable turbine working passage construction comprising alternate rows or rings of fluid directing means and-movable bucket means with clearance spaces adjacent thereto and communicating with the Working passage.

Now in accordance with the invention, the leakage elastic fluid is conducted through ports or passages 14: and 15 in the nozzle and bucket bases or supporting means respectively. The passages extend in the direction or fluid flow from one side of the blade or bucket ring to the other and serve to connect the successive leakage spaces 10 and 12 and leaka e spaces 9 with which said leakage spaces communicate, and provide with the leakage spaces 10 and 12, a pair of annular leakage fluid conduits paralleling the Working passage. The leakage fluid tends to flow in a continuous stream through the conduits thus provided, as indicated by lines 16, thereby permitting the main elastic fluid stream indicated by lines 17 to flow undisturbed.

WVithout this conduit means for the leakage elastic fluid, the latter tends to flow into the mainstream through spaces 9 and interferes with'the steady flow of said main stream, thereby effecting a certain reduction of efficiency in the operation of the turbine as hereinbefore described.

One construction which may be employed to form the passages through the blade or bucket rows is that shown in Figs. 2 and 3 in which, between the buckets 7 for example, are provided bucket spacing blocks 18 of the type indicated. Passages 15 are provided in these blocks by grooving each of them on one face, as indicated in Fig. 2, so that one wall of each passage is formed by the adjacent bucket.

In this figure it will be noted that passage 15 is curved with the bucket so that the leak age elastic fluid in passing therethrough will give up its energy to the rotating parts. This represents a gain in efficiency in addition to thatgained by isolating the leakage fluid current from the main elastic fluid stream. The leakage conducting passages may be provided by any other suitable means than that shown and described, although for the reasonof its simplicity, it is at present the preferred form. The passages 14 in the base section of the fluid directing blade rows or rings are formed in a similar manner.

The cross-sectional area of each ventilating passage is preferably such that the pressure of the leakage elastic fluid at the outlet end thereof is equal to the pressure in the adjacent leakage space 9 between the fluid directing means and the succeeding rows of buckets. With this arrangement there is less tendency for even a slight deviation of either the flow of leakage fluid stream, as indicated at 19, Fig. 1 or of the main elastic fluid stream. 7

The use of parallel fluid conduits along the working passage provided by ports or passages through the base or supporting structure of the fluid directing blades and buckets, connecting the leakage spaces, has a fur ther advantage in that water of condensation in steam turbines, for example, may be thrown out from the buckets into these conduits through the leakage spaces or gaps 9 without interference from the leakage .steam, which, in the ordinary construction, flows in a direction such that it keeps the condensation in the working passage where it tends to erode the buckets by its passage therethrough.

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

1. The combination with an elastic-fluid turbine having alternate rows of fluid directing and movab e blades, which cooperate to provide an elastic fluid working passage, said blades each having a base portion by which it is mounted and a free end about Which leakage elastic fluid flows, of means for preventing said leakage elastic fluid from entering the working passage, said means comprising passages extending in the direction of fluid flow through the base portions of said blades and connecting the leakage spaces on opposite sides thereof, whereby said spaces and passages form a fluid conduit extending along the working passage.

2. The combination with an elastic-fluid turbine having alternate rows of fluid directing and movable blades, which cooperate to provide an elastic fluid working passage, said blades each having a base portion by which it is mounted and a free end about which leakage elastic fluid flows, of means for preventing said leakage elastic fluid from entering the working passage, said means COlIlPl'lSlDg passages extending in the direction of fluid flow through the base portions of said blades and connecting the leakage spaces on opposite sides thereof, whereby said spaces and passages form a fluid conduit extending along the working passage, said passages being curved in a direction to cause the leakage fluid to give up its energy in flowing therethrough.

3. The combination with an elastic-fluid turbine having alternate rows of fluid directing and movable blades, which cooperate to provide an elastic fluid Working passage, said blades each having a base portion by which it is mounted and a free end about which leakage elastic fluid flows, of means for preventing said leakage elastic fluid from entering the working passage, said means comprising passages extending in the direction of fluid flow through the base portions of said blades and connecting the leakage spaces on opposite sides thereof, whereby said spaces and passages form a fluid conduit extending along the working passage, said passage being curved in a direction to cause the leakage fluid to give up its energy in flowing therethrough and being of such cross section that the pressure at the outer end of each passage is substantially equal to the pressure in the leakage space with which it is con nected.

In Witness whereof, I have hereunto set my hand this 26th day of March, 1928.

OTTO aosENLooHEn.

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