US1321396A - Turbine. - Google Patents

Description

H. F. SCHMIDT.

TURBINE.

APPLICATION min 001.2. 1916.

1,321,396. Patented Nov. 11, 1919.

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INVENTOR.

HIS ATTORNEY I FACT UNI ED STATES ATENT HENRY F. SCHMIDT, or PITTSBURGH, PENNSYLVA IA, ASSIGNOR T WESTINGHOUSE ELECTRIC &iviANUEAcTUEINe C01VIVPANY,\A CORPORATION or PENNSYLVANIA.

TURBINE.

SpecificationofLetters Patent. Patented NOV. 11, 1919.

Application filed October 2, 1916. 7 Serial No. 123,346.

To all whom it may concern:

Be it known that I, HENRY ESCHMIDI,

a citizen of the United States, and a resident of Pittsburgh, in the county of Allegheny and State of Pennsylvania, have made a new countered in the propulsionof ships. 1

A further object of my invention is to provide a single turbine unit which will operate with high eliiciency at full speed and cruisv ing speeds and which is also capableof being reversed.

A further object is to produce a compact and simple form of turbine in which means are employed for controlling the delivery of fluid through the rotor of the turbine to one of the working elements of the turbine.

A further object is to produce a marine turbine of simple and compact form, which is'capable of operating at high efiiciency at difierent speeds. v r V A further object is to produce a turbine in which some of the elements at times'run idle and in which means are employed for reducing the frictionlosses occasioned by running these elements idle. 7

These and other objects are attained by means of the apparatus illustrated in the drawing accompanying and forming a part hereof.

In the drawing:

Figure 1 is a diagrammatic longitudinal section of a turbine embodying my inven- Eli tion.

'Fig. 2 is a similar view of a modified form of. my invention.

The turbines illustrated as embodiments of my invention each include ahead and reversing elements. The ahead elements are so designed that the turbine is capable of operating with high efficiency throughout a wide range of loads. This is accomplished by dividing the'working elements into sectioiis andso arranging the sections that a portion only of'tlie working elements are operative, while the turbine is operating at reduced s seed or isdeveloping less than full power. Anotherfeature of'my invention is that I iii-crease the effective cf the low Fig. 3 illustrates a detail of'my invention] 1 pressure working elements when the turbine is operating at full speed or is developing maximum power.

section, which is adapted to run idle, while the turbine is developing less than full power, but is adapted-to operate in parallel with the main low pressure section when the turbine is developing full power. This renders it possible to reduce the diameter of the turbine and particularly'of the low pressure section below that of ordinary turbines having the same capacity, and it also reduces the length of the low pressure blades or elements, and results in a turbine of simpler and lighter construction than those in which all of the motive fluid is discharged through a single set of low pressure working elements.

In Fig. 1,1'have shown a turbine having a casing 5 and a rotor 6. The interior of the turbine is divided into ahead and reversing SQCtlODSbY an interleaving packing 7 located between the rotor and the casing. The ahead section is showiilocated at the right ofthe packing and the reversing section is located at the left of the packing.

The ahead section'is provided with an inlet port 8, which, as shown, communicates with an annular chamber 8 and is adapted to deliver fluid to'no'zzles 9. The nozzles 9 are illustrated as divergent nozzles and form a part of an initial section 10, which is illustrated as a multiple velocity drop impulse stage and includes two rows of moving *blades, diagrammatically shown as mounted on a rotor wheel 10 and cooperate with an intermediate row of stationary blades, mounted on the casing. Any suitable and well known means may be employed for obtaining nozzle control, whereby the number of nozzles 9, effective in delivering fluid to the blades of the initial stage may be varied. I

This initial stage may therefore be termed a partial or variable admission stage or section, since motive fluid may be delivered to less than the total number of blades of the first rOW of blades, and the number of blades of the first row simultaneously receiving fluid may be varied. I

The fluid issuing from the last row of bladesof the initial section i's'delivered to an intermediate section 11, which is illustrated -asof the full peripheraladmission type, and

provided witl'i a row of moving FFIGE.

This is accon'iplished by providing an auxiliary low pressure ahead blades per stage. By the term stage is meant, cooperating turbine elements which expand the motive fluid and abstract substantially all the velocity energy rendered available by the expansion.

The fluid issuing from the intermediate section is divided into two streams, each of which is delivered to one division of a divided low pressure section. The low pressure section illustrated is of the same type as the intermediate section and its divisions 12 and 13 are so arranged that the motive fluid passes through them in opposite axial directions. 11s illustrated in Fig. 1, this is accomplished by so locating the divisions of the low pressure section. that their exhaust ends are adjacent to each other and communicate with a common exhaust passage 17, which, in .turn, communicates with the exhaust port 17. The fluid issuing from the intermediate section is divided at a point adjacent to the last row of blades of that section, one stream passing directly to the inlet end of the division 12, whereas the other stream is delivered to the inlet end of the division 13 of the low pressure section, through suitable ports and passages formed within the rotor (3.

As shown, the moving blades of both divisions of the low pressure section are mounted on a drum let of greater diameter than the remainder of the rotor and which forms a part of the rotor. This drum is provided with ports 15 and 16 and an interior passage through which fluid is delivered from the intermediate section to the inlet end of the division 13.

' In order that the supply of fluid may be shut off to the division 13 of the low pressure stage, when the load conditions are such that the division 12operating alone can eiliciently expand all of the fluid issuing from the section 11, I have provided a valve 21 between the inlet end of the section 13 and the delivery end of the section 11. As illustrated, this valve controls communication between a chamber 18, formed within the casing 5, and a chamber 13, also formed within the casing and communicating directly with the inlet end of the division 13 of the low ressure section. The chamber 18 connnunicates with the ports 16 of the rotor and is segregated from the other fluid passages of the turbine by means of a pack ing 19, a diaphragm 20 and a packing 30. The packing 19 is located between the diaphragm 20 and the peripheral face of the drum 14, and the packing 30 is located between a reentrant flange, formed on the easing- 5, and a portion of the rotor 6 of less dian'ieter than the drum 1 1. This packing and its cooperating flange also segregate a chamber 29, located between the end of the rotor 6 and the end wall of the casin 5. For the purpose of equalizing the lateral or endwise pressures on the rotor the chamber 29 is placed in communication with the exhaust chamber 17 through a passage 31.

The reversing section of the turbine includes an initial stage 25 and a low pressure stage 26. As shown the initial stage 25 is similar to the stage 10, whereas the section 26 is illustrated as of the full peripheral admission type. An inlet passage 23 communicates with a chamber 23 and is adapted to deliver motive fluid to the nozzles of the stage 25. The section 26 operates on fluid delivered from the section 25, and dis charges into a separate exhaust passage 27 In Fig. 2, I have illustrated a modified form of my invention. The turbine includes ahead and reversing sections. The ahead section includes an initial stage 31, which may be of the impulse or partial or variable admission type, an intermediate section 32,.

preferably of the full peripheral admission type, and a divided low pressurersection. The divisions 33 and 34 of the low pressure section are located at opposite ends of the casing and are so arranged that fluid flows through them in opposite axial directions.

Motive fluid issuing from the last row of blades of the initial section 31 is delivered to the section 32. The fluid issuing from the section 32 is divided into two streams, one of which passes directly to th division 33 of the low pressure section, whereas the other is delivered, through ports 35 and 36 and a passage formed within the rotor, to a chamber 37, which surrounds the rotor and is in direct communication with the ports 36. 'This chamber is segregated from the other fluid passages of the turbine casing by means of packings 38 and 39 and partitions shown as formed integrally with the turbine casing. Communication between the chamber 37 and the inlet end of the di vision 34, of the low pressure section, is controlled by means of a valve 410, which is adapted to control a port formed in one of the walls of the chamber 37. With this ar rangement the division 34 may be rendered inoperative as a power developing element of the turbine by closing the valve 40, or it may be caused to be operated in parallel with the section 33 by opening the valve. Each division of the low pressure section discharges into a separate exhaust passage 41, located at each end of the turbine casing.

. The reversing element of the turbine illus-' trated in Fig. 2 consists of two reversing sections 43, each of which is adapted to receive high pressure steam, and is located in one of the exhaust passages 41 of the turbine casing. Each reversing section illustrated is of the type in which the steam is delivered at a high velocity to successive impulse buckets of a series. As shown, each section consists of a series of impulse buckets 454K, mounted on the rotor element of the turbine, and a cooperating series of stationary redirecting buckets, each bucket of which is adapted to receive fluid discharged from one bucket of the moving series and to redirect it into a successive bucket of that series. Fluid is delivered to the initial bucket of the moving series through an expansion nozzle 45, which is adapted to receive high pressure motive fluid through a passage 16 and is adapted to expand the fluid to exhaust pressure. The stationary buckets are mounted on the casing of the turbine in any suitable manner. Inasmuch as each reversing section is located in an exhaust passage of the turbine, a separate exhaust passage is unnecessary and in addition the frictional losses occasioned by the reversing section when the turbine is running ahead are slight.

In Fig. 3 I have diagrammatically illus trated means for controlling the delivery of motive fluid to the separate nozzles of either the ahead or reversing sections. In this figure I have numbered the separate parts to correspond to the reference numbers em ployed in connection wit-h the ahead section of Fig. 1, although it will be apparent that the apparatus illustrated may be employed for controlling the delivery nozzles of the reversing section shown in Fig. 1 or the.

delivery nozzles of the ahead or reversing section of Fig. 2. As illustrated, the inlet ends of the nozzles 9 are provided with a cover valve 47, which is arch-shaped, and is adapted to be moved by means of a worm 48 and rack 49 to difierent positions so that it will cover or uncover one or more of the nozzles 9 and thereby control the delivery of fluid from the chamber 8 to these nozzles.

The operation of the turbine illustrated in Fig. 1 is as follows: Motive fluid is delivered to the ahead section through the inlet port 8 and is expanded by the nozzles 9 and delivered to the blades of the section 10. Fluid issuing from this section is further expanded as it traverses the working elements of the section 11 and is divided into two streams upon issuing from the section 11, one of which is delivered to the division 12 of the low pressure section, whereas the other is delivered through the passage formed within the drum 14 to the chamber 18. Under reduced power conditions, the valve 21 is closed and all the motive fluid delivered through the nozzles 9 is passed through the section 12 to the ex haust port 17'. Under full power conditions, the valve 21 is opened and the divisions 1'2 and 13 of the low pressure section operate in parallel, the fluid discharged from each of these sections entering thechamber 17.

\Vhen it is desired to reverse the turbine the fluid supply through the passage 8 is cut ofl? and high pressure fluid is delivered to the nozzles of the section 2 5. The motive fluid passes in series through the sections 25 and 2 6 and is discharged through a separate exhaust passage 27.

It will of course be understood that the delivery of motive fluid through either the ahead or reversing section may be controlled by a valve a7 with which the nozzles are provided.

The operation of the turbine illustrated in Fig. 2 is similar to that of the turbine illustrated in Fig. 1, except that the sepa rate divisions of the low pressure section discharge into the separate exhaust passages 4:1.

One of the advantages of the turbine illustrated is that it is'capable of operating efiiciently under a wide range of loads. Another advantage is that the turbine elements running idle are exposed to vacuum or condenser pressure and that therefore frictional losses are minimized. It: will also be apparent that a marine turbine embodying my invention is a material improvement over other marine turbines, since the ahead elements run idle only while the turbine is operating at reduced speed. This, taken in conjunction with the fact that the idle running elements are subjected to condenser pressure, reduces the wlndage, or so called wind frictions, to such an extent that the losses and detrimental effects occasioned by running the elements idle, are so reduced as as not to be detrimental to the operation of the turbine.

While I have described but one embodiment of my invention, it will be apparent to those skilled in the art that various changes, modifications, additions and omissions may be made in the apparatus illustrated Without departing from the spirit and scope of the invention as set forth by the appended. claims.

What I claim is:

1. A turbine provided with but a single rotor and comprising a high pressure section, a low pressure section receiving partially expanded fluid from the high pressure section and a passage in the rotor for delivering fluid from the high pressure section to the low pressure section, characterized by that means are provided between the high pressure section and low pressure section for controlling the delivery of fluid through the passage in the rotor.

2. A turbine provided with but a single rotor, and comprising a high pressure section, a divided low pressure section operating in parallel on partially expanded fluid from the high pressure section, characterized by that a passage is provided in the rotor for delivering fluid from the high pressure section to one of the divisions of the low pressure section and means are employed for controlling the delivery of fluid through said passage in the rotor.

3. A turbine comprising a high pressure section, a divided flow low pressure section, the separate divisions of which are adapted to operate in parallel on fluid delivered from the high pressure section, a passage formed within the rotor of the turbine for delivering fluid to one division of the low pressure section, and means for controlling the delivery of fluid through the rotor passage to the division of the low pressure section.

at. A turbine comprising a high pressure section, a low pressure sect-ion adapted to receive fluid from the high pressure section, a passage in the rotor for delivering fluid to the low pressure section and means for controlling the delivery of fluid to the low pressure section.

5. A turbine comprising a high pressure section, a low pressure section, a passage formed within the rotor of the turbine for delivering fluid from the high to the low pressure section, and a valve for controlling the delivery of fluid through said passage to the low pressure element.

6. A turbine comprising a high pressure section, a divided flow low pressure section adapted to operate in parallel 011 fluid discharged from the high pressure section, a passage formed within the turbine rotor for delivering fluid from the high pressure section to one division of the low pressure section, and a valve for controlling the delivery of fluid through said passage.

7. In combination in a turbine, a partial or variable admission high pressure section, a divided low pressure section, the separate sections of which are adapted to operate in parallel on fluid discharged from the high pressure section, a reversing section, a single casing and a common rotor to all of said sections.

8. A turbine comprising a high pressure section and a divided flow low pressure section located within the same casing with the high pressure section, in combination with a rotor passage between the high pressure section and one division of the low pressure section, a seal between the casing and said one division of the low pressure section, and a valve for controlling the delivery of fluid from the high pressure section past said seal and to said one division of the low pressure section.

In testimony whereof, I have hereunto subscribed my name this 28th day of September, 1916.

HENRY F. SCHMIDT.

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

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