US2332322A

US2332322A - Elastic fluid turbine arrangement

Info

Publication number: US2332322A
Application number: US365905A
Authority: US
Inventors: Kraft Hans
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1940-11-16
Filing date: 1940-11-16
Publication date: 1943-10-19
Anticipated expiration: 1960-10-19

Description

Oct. 19, 1943. H. KRAFT ELASTIC FLUID TURBINE ARRANGEMENT Filed Nov. 16, 1940 Inventor:

v H ahs K'PaFt, by WW c.

His Attorn ey.

Patented Oct. 19,1943

UNITED ,TS'l'ATES- PATENT OFFICE anasrro FLUID- rename ARRANGEMENT Hans Kraft, Schenectady, N. Y., asslgnor to Gencral'Electrlc Company, a corporation of New v York Application Name; 16, 1940, Serial No. 365,905

Claims. (or. 253-76) er of fluid in the stationary nozzle passages is eifectively removed. a

This is accomplished in accordance with my invention by the provision of an elastic fluid turbine having a row or rows of stationary nozto-a shaft 21. A row of radial buckets 28 is suitably secured to the rim of the disk 26 and a shroud band 29 is fastened to the outer ends of the buckets. Each diaphragm has an inner member or disk 30 sealed to the shaft 21 by a packing 3| and a row of partitions or blades 32 secured between the rim of the disk and an outer zles for conducting elastic fluid to rows of buck- 'ets on a bucket wheel or wheels, which buckets have a radial h'eight smaller than the radial height of the corresponding nozzle passages. Scoops are provided adjacent the inner and outer ends of the buckets for receiving fluid from the boundary layer and conducting it to a channel. This fluid in accordance with my invention is utilized for preheating condensate discharged from the turbine condenser.

Fora better understanding of what I believe to be novel and my invention, attention is directed to the following description and the claims appended thereto in connection with the accompanying drawing.

In the drawing Fig. 1 illustrates an elastic fluid turbine arrangement in accordance with my invention; Fig. 2 is an enlarged sectional view of a part of Fig. 1; and Fig. 3 is a sectional view along line 3-3 of Fig. 2.

The arrangement comprises an elastic fluid turbine In with a shell H and an exhaust conduit l2 connected to a condenser l3. Condensate discharged from the condenser I 3 is forced by means oi'a condensate pump l4 to a flrst preh'eater I5 having a heating coil l6 and being connected to discharge preheated condensate into a second preheater I! with a heating coil I 8. The preheater i! has a discharge conduit I!) for connection to an elastic fluidgenerator or boiler, not shown. The heating coils'lfi' and I8 of the preheaters l5 and I! are connected to supply conduits and 2| respectively for receiving heating fluid from the turbine.

The turbine as shown in Fig. 2 has

bucket wheels

22, 23 and

diaphragms

24 and 25 for conducting elastic fiuid to the

wheels

22, 23 respectively. Each bucket wheel has a disk 26 secured ring 33 held on the casing ll. 1

During operation, elastic fluid is directed by the nozzle passages formed between the blades 32 of the high pressure diaphragm 24 towards the bucke'ts28 of the bucket wheel 22. The, fluid I discharged from the bucket wheel 22 is conducted through the nozzle passages formed by the second or low pressure diaphragm 25 to the bucket wheel 23. I

The fluid flowing through the nozzle passages has maximum velocity in the central portion of these passages. The velocity decreases towards the outer portion and becomes a minimum at the walls formed by the blades, the disk 30, and the ring 33. Thus, during operation a boundary layer of relatively slowly flowing fluid is formed in each passage. This boundary layer of slowly flowing fluid does little work when conducted into' the passages formed between the buckets of a bucket wheel. Therefore, in accordance with my invention, means are provided preventing at least part of the boundary layer-oi fluid in the stationary diaphragms from entering the rotating bucket wheels. To this end the buckets 28 of the bucket wheels have aradial length or height smaller than the radial length or height of the blades or partitions 32 of the corresponding diaphragms. The. outer and inner ends of the thin outlet edges of-the partitions 32 are cut away to form a shortened intermediate outlet edge 3 closely spaced with the buckets of the succeeding wheel.

The ends of the partitions extend radially beyond the ends of the .corresponding buckets. From another viewpoint, the disk of the bucket wheel 22 has a larger diameter than the disk 30 32. Similarly the casing H is provided with annular projections 36 closely spaced with the cutaway, outer, thin outlet edges of the blades 32 and forming scoops for receiving the boundary 7 layers formed in the outer portions of the nozzle passages. The fluidof the outer boundary layers is conducted through a passage 31 formed between the outer ring 33 of the diaphragm and the casing ll into a channel or channels 38 which discharges the fluid into a chamber 39 formed by the casing II.

The inner boundary layer in the nozzle passages is received by the scoops 35 and conducted into a space 40 formed between adjacent diaphragms and bucket wheels, whence the fluid is conducted to the aforementioned chamber 33 of the casing II. To this end the thick inlet portions of at least some of the partitions or blades 32 are provided with radial bores 4| which at their inner ends communicate through channels 42 with the space 40 and at their outer ends communicate through channels 43 with the channels 38.

During operation fluid flowing through the central portions of the nozzle passages is conducted to the bucket wheels whereas the inner boundary layer is conducted through the space 40, the channels 42, the bores 4| and the channels 43 and 38 to the chamber 39. The space 40 also receives leakage fluid flowing along the shaft. The fluid of the outer boundary layer is conducted through the passage 43 and the channel 38 to the chamber 39.

In the present arrangement the chamber 39 receives the fluid of the boundary layers from the two

diaphragms

24 and 25. The chamber 39 is connected to discharge fluid into the aforementioned supply conduit 2| for preheating the condensate in the second preheater H. A similar chamber 44 (Fig. 1) is formed to receive fluid from boundary layers 01 lower turbine stages and discharge such fluid into the supply conduit 20 of the first preheater I 5.

Having described the method of operation of my invention, together with the apparatus which I- now consider to represent the best embodiment thereof, I desire to have it understood that the apparatus shown is only illustrative and that the invention may be carried out by other means.

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

1. Elastic fluid turbine comprising a casing, a

diaphragm supported on the casing and forming a row of nozzle passages and a bucket wheel having a row of buckets associated with the nozzles nozzle passages from entering the bucket wheel to separate the boundary layers of fluid from the remaining fluid.

2. Elastic fluid turbine comprising a casing, a diaphragm supported on the casing and forming a row of nozzles, a bucket wheel having a row of buckets associated with the nozzles and being of a radial height shorter than the radial height of the nozzle passages, the bucket wheel diameter at the inner ends of the buckets being larger than the diaphragm diameter at the inner ends of the nozzles, and means including a scoop formed on the bucket wheel adjacent the roots of the buckets for receiving the inner boundary layer from the nozzle passages, and channel means for removing said layer from the turbine.

3. Elastic fluid turbine comprising a casing forming a fluid chamber, a diaphragm having a disk, a plurality of radial partitions with inner ends secured to the disk and an outer ring supported on the casing and secured to the outer ends ofthepartitions, a bucket wheel having a row of buckets for receiving fluid from the diaphragm, the radial height of the buckets being smaller than the radial height of the partitions, and means forming channels for conducting fluid from the inner and outer boundary layers formed in the nozzle passages to said chamber to separate the fluid of the boundary layer from the remaining fluid and to remove the fluid of the boundary layers from the turbine, said means including the disk and the ring and radial bores through at least some of the partitions.

4. Elastic fluid turbine comprising a casing forming a fluid chamber, a diaphragm having a disk, a plurality of radial partitions with inner ends secured to the disk and an outer ring supported on the casing and secured to the outer ends of the partitions, a rotor comprising a shaft and a bucket wheel secured to the shaft disposed within the casing and spaced from the diaphragm, a packing to reduce leakage along the shaft past the diaphragm, and means for receiving leakage passing along said packing into the space between the diaphragm and the bucket wheel, said means including channels formed in the disk and the partitions and said chamber.

5. Elastic fluid turbine comprising a casing, a diaphragm having a disk with a plurality of partitions forming nozzle passages supported on the casing, a rotor having a shaft and a bucket wheel secured to the shaft disposed within the casing and arranged to receive fluid from the passages formed by the diaphragm, the bucket wheel being spaced from the diaphragm, and means including radial bores in the partitions and channels in the disk for receiving fluid from the space between the disk and the bucket wheel and for removing such fluid from the turbine.

HANS -KRAFT.