US1329515A - Elastic-fluid turbine - Google Patents

Description

G. EGGER.

ELASTIC FLUID TURBINE.

APPLICATION FILED NOV.2l, 191s.

Patented Feb. 3,1920.

2 SHEETSSHEET l 'y diiofaqy G. EGGER.

' ELASTIC FLUID TURBINE.

APPLICATIONFILED Nov.21.1918.

1,329,515. Patented Feb. 3,1920.

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UNITED STATES PATENT OFFICE.

GUSTAV EGGEE, OF VIELLSVILLE, NEW YORK.

ELASTIC-FLUID TURBINE.

Application filed November 21, 1918.

To all whom itmag concern Be it known that I, GUs'rAv EGGER, a citizen of Switzerland, and resident of lVellsville, county of Allegany, State of New York, have invented an Improvement 1n Elastic-Fluid Turbines, of which the following description, in connection witlrthe ac-- companying drawings, is a specification, like characters on the drawings representing like parts in each of the several views.

This invention relates'to elastic fluid turbines and is particularly directed to improvements in the transmission of the driving fluid from the pressure supply conduit to the rotor of the turbine. A principal object of the invention is to provide means for introducing the fluid to the rotor in the form of a pressure jet whereby an ejector action with suction effect is obtained at the joint of the rotor with the relatively fixed conduit housing. A further object is to provide improved means of balancing the end thrust on the rotor occasioned by the introduction of the driving fluid.

In previous constructions of elastic fluid turbines such as a certain reaction type, difficulties have been experienced by reason of the loss due to the leakage of the fluid between the stationary and revolving parts at the point of introduction of fluid under pressure to the interior of the rotor, this loss being in direct proportion to the pres sure at the joint and the size of the joint diameter. According to the present invention this loss is reduced to a minimum by expansion of the fluid before it enters the rotor with the subsequent conversion of its kinetic energy back into pressure in the rotor before it emerges from the reaction nozzles in the rotor. This result is attained by means of a nozzle combined with a diffuser, the latter located in the rotor, and the method employed may be considered as a. specific application of Bernouillis law in a manner generally analogous to that exhibited in the familiar Venturi tube. According to this law, neglecting friction, the sums of the pressure head and velocity head of the liquid flowing through a conduit of chang ing area is constant. Thus when an elastic fluid passes a nozzle and a diffuser in succession, its pressure and temperature decrease in the nozzle while its velocity is accelerated; while in the diffuser this increase in velocity head is converted back into pressure head accompaniedby a rise in temperature.

Specification of Letters Patent.

Patented Feb. 3, 1920.

Serial No. 263,599.

jet. By reason of the relatively constricted inlet passage the diameter of the packing at the joint is correspondingly small which results in a relatively small clearance space between the packing and rotor. This reductionof pressure, temperature and packing diameter at the inlet is a very desirable feature, the low pressure and small diameter resulting in a small leakage loss and he low temperature permitting the packing to operate under favorable conditions avoiding warping and undue expansion of the parts and reducing the radiation loss, thus eliminating the one serious difficulty heretofore encountered with this turbine type. Comparing the merits of the present new arrangement with an unconstricted inlet there is assured a reduction to the extent of seventyfive per cent. in the leakage loss by reason of the lower pressure and smaller joint diameter. It will be understood that in the case of small capacity turbines a leakage loss at this point is direct heat loss since the leaking fluid cannot be utilized in the turbine as it is not under the control of the gov ernor and might cause the turbine to run' in a direct heat loss for the reason that ex cept for leakage and radiation the heat of the fluid after-passing the difiuser is the same as at the inlet to the nozzle and the re heat due to friction is utilized to a certain extent in the turbine. On the other hand the radiation losses with the use of the present jet nozzle and diffuser are of course smaller than with an unconstricted inlet. Further the end thrust upon the rotor resulting from the admission of the fluid to an open rotor end is less on account of the smaller area at the inlet that is subject to lower pressure. Since the pressure at the nozzle throat depends upon the rate of flow, it follows that the full advantage of the present improvements are only obtainable when the turbine is carrying its full load. However since even the slightest pressure drop between. the nozzle inlet and the diffuser exit results in a considerable suction effect it follows that even for partial loads the present turbine exhibits marked advantages. he distinctive objects and advantages of the invention will more fully appear from the following detailed description, an the distinctive featur s of novelty will be pointed out in the appended claims.

Referring to the drawings:

Figure 1 is a central lengthwise sectlon of a turbine constructed in accordance with my invention, a generator extension of the housing being shown in elevation;

Fig. 2 is a transverse section on line 22 of Fig. 1; and

Fig. 3 is a detail lengthwise section at the inlet nozzle, showing a modification.

1 indicates a stationary nozzle secured at the end of a pressure conduit 1 supplying the elastic driving fluid. This nozzle is mounted in alinement with, and adjacent to the open rotor end 2 which consists in a hollow shaft which may serve as a bearing support for the rotor or serve simply as a fluid conduit to the interior of the hollow rotor as shown, the fluid passage through this rotor shaft end having a flaring receiving mouth 2 and said passage being slightly larger than the jet nozzle 1. The passage through the rotor end 2- leads to an expanding chamber or dif user 3 where the cross sectional area of said passage gradually expands and the pressure fluid as it passes therethrough is reduced as to velocity and increases in pressure and temperature. small clearance space 4i is provided between the nozzle 1 and the rotor end and. by reason of the ejector action of the nozzle jet and with the slightly larger cross section of the receiving passage in the rotor end 2, the fluid in this clearance space is partially exhausted and carried along with the jet resulting in a materially lower pressure in this space. The rotor end 2 equipped with suitable packing rings 5 is fitted in a projecting neck portion 7 of the turbine casing 7 and has clamped to the end thereof the inlet flange 6 which is equipped with the inlet nozzle 1 and into which the inlet pipe 1 is threaded. A leakage space 8 is formed around the rotor end some distance from the extremity thereof and behind most of the series of packing rings 5, this leakage space communicating with an equalizing pipe 9 leading to an equalizing chaniiber 10 formed to extend around the inner wall 7 of the turbine casing. The turbine wheel 11 is equipped with an outer ring portion presenting a face 12 to cooperate with the equalizing chamber 10 as an equalizing piston to be acted on by the pressure transmitted to said equalizing chamber. Between this equalizing chamber and the exhaust passage 14- a narrow passage 13 communicates which is constituted by the leakage space between a lateral rim flange 13 at the periphery of the rotor and a shallow annular recess or socket 13 into which this rim flange loosely its. 15 indicates the sliding valve stem of a centrifugal governor mechanism revolving with the rotor, said stem mounted to slide radially of the rotor axis and intersecting the same, and equipped with a valve 15 controlling the flow of motive fluid from the diffuser to the discharge nozzles of the rotor.

This valve stem has adjustably mounted at one end portion thereof weight 15', the adjustment whereof varies the centrifugal force tending to close the valve, while a compression coil spring 15 mounted to react against an adjustable cap 15 on the other end of the valve stem tends to keep the governor valve open, and does in fact keep it open variably to the extent required to maintain aconstant speed under varying conditions of the motive fluid pressure and load, the centrifugal action closing the same gradually as the speed tends to become excessive. 16 indicates a bearing compartment with a labyrinth packing 17 between the same and the equalizing chamber 10. The shaft mounting 11 of the rotor is equipped with suitable ball bearings 11 and is shown as directly connected to a generator G, this of course merely typifyinp; any suitable driven connection. 18 indicates the reaction jet nozzles of the rotor, illustratively shown as four in number and preferably discharging substantially tangentially of the rotor periphery against a set of stationary blades 19 which guides the fluid to a set of revolving buckets 20, carried by the rotor, the rotor being shown as equipped with a still further set of revolving blades 22 with another interveningset of stationary blades 21, the extent to which this compounding of blades is carried being of course optional and the present showing being merely illustrative and forming no part of the present invention. The equalizing pipe 9 is preferably equipped with a valve 9 which may be adjusted so as to vary the pressure in the equalizing chamber 10 according to require merits. in Fig. 3 I show a form of the invention wherein no separate stationary nozzle is provided but the inlet pipe 1 delivers directly into the receiving throat 23 of the hollow rotor end which corresponds to the rotor end 2 as first described. In this way the inlet passage of the rotor itself may be considered to form the nozzle and thus the end thrust of the rotor is kept fairly constant which is desirable in certain cases, this resulting from the fact that the pressure at the joint is substantially constant being equal to the initial pressure of the fluid.

It will be. understood that since the pressure of the leaking fluid at a point within the packing, z'. 8., in the leakage space 8 min direct proportion to the pressure upon the rotor end, hence this fluid delivered through the pipe 9 to the equalizing chamber 10 will exert its pressure upon the equalizing piston 1:2 of the rotor in a direction opposite to the thrust against the rotor end and proportional thereto. Since a certain period of time is required for a change in inlet pressure to afl'ect the fluid in the equalizing chamber and produce the proper pressure therein by reason of the relatively slow leakage past the packing, I provide means whereby a slight endwise play or motion of the rotor in the direction of the resultant thrust accomplishes the balancing eflect immediately. Thus with an increase of inlet pressure the constricted annular passage 18 to the exhaust becomes still smaller and hence the pressure in the equalizing chamber at once increases to a point where the thrust is again balanced. Then as the pressure in the chamber tends to rise still further the rotor is pressed back to its previous position. It will be understood that in the case of a condensing steam turbine the pressure of the fluid in the chamber may be utilized for preventing air from entering the turbine through the labyrinth packing 17. I am aware that the invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof, and I therefore desire the present embodiment to be considered in all respects as illustrative and not restrictive reference being had to the appended claims rather than to the foregoing description to indicate the scope of the invention.

Having described my invention, what I claim as new and desire to secure by Letters Patent is:

1. An elastic fluid turbine, comprising a rotor with a diffuser therein constructed and arranged to decrease the velocity and increase the pressure of the driving fluid, a fluid regulating governor mechanism in said rotor receiving the driving fluid from said diffuser at a relatively low velocity, and means for admitting driving fluid to the rotor consisting in a stationary nozzle of relatively restricted dimension.

2. An elastic fluid turbine, comprising a rotor equipped with a diffuser constructed and arranged to decrease the velocity and increase the pressure of the driving fluid, said rotor also bearing a governor mechanism arranged to receive the driving fluid from the diffuser at a relatively low velocity, and means for admitting driving fluid to said rotor consisting in a nozzle adapted to deliver the driving fluid as a jet to the difl'user.

3. An elastic fluid turbine, comprising a rotor with a diffuser and a governor mechanism therein arranged to receive the driving fluid from the diffuser at a relatively low velocity, and means for admitting driving fluid thereto consisting in a nozzle arranged to deliver the driving fluid as a jet.

4:. An elastic fluid turbine, comprising a rotor equipped with a difl'user and also with a fluid regulating governor mechanism receiving the fluid at a relatively low velocity from the diffuser connected with an axial passage for the admission of driving fluid, and a relatively stationary nozzle arranged to deliver the driving fluid as a jet into said axial rotor passage.

5. An elastic fluid turbine, comprising a rotor having an axial inlet passage leading to a difiuser constructed and arranged to increase the pressure and decrease the velocity of the driving fluid, and a relatively stationary nozzle of slightly smaller dimension than said passage arranged to deliver the driving fluid as a jet thereto, said diffuser having a governor controlled passage leading therefrom to the discharge nozzles of the rotor.

6. An elastic fluid turbine, comprising a rotor equipped with a hollow open end with a difluser connected thereto adapted to decrease the velocity and increase the pressure of the driving fluid, said rotor also equipped with a governor mechanism receiving the fluid fromsaid difluser, a relatively stationary nozzle opposite and close to said rotor end, and means for reducing the leakage of fluid at said rotor end.

7. An elastic fluid turbine, comprising 'a rotor having an axial passage at one end thereof for the admission of the driving fluid, means for delivering the fluid to said end as a jet, means for packing said rotor end, an equalizing chamber equipped for counterbalancing end thrust by means of the leaking fluid, and means associated with said packing having a connection to said equalizing chamber.

8. An elastic fluid turbine, comprising a rotor having an axial inlet at one end thereof with means for delivering fluid to said inlet as a pressure jet, means for packing said rotor end, an equalizing piston associated with said rotor and having a connection to receive leakage from said packing, and means permitting a constricted discharge :t'rom the chamber of said piston to the exhaust variable according to the inlet pressure.

9. An elastic fluid turbine, comprising a rotor having an inlet passage at one end thereof, a relatively larger piston at the other end of said rotor cooperative with an equalizing chamber, and a connection for delivering leakage from the inlet rotor end to said chamber, said rotor having provision for controlling a constricted discharge from. said chamber to the exhaust whereby said chamberis opened more or less tothe exhaustby endvvise movement of the rotor dueto variations in pressure.

10. A condensing steam turbine having a rotor equipped'vv-ith an open end to receive the. driving fluid, and an equalizing cham her and piston at the other-end of the rotor having a connection to receive leakage from the inlet rotor end and arranged to form also a steam seal against ,air admission to the turbine.

11. An elastic fluid turbine, comprising a rotor having provision for the admission of driving fluid at one end thereof and equippedvvith a difiuseradapted to decrease thevelocity and increase the pressure of the driving fluid and with a governor mecha- DlSHLCZUllQd thereby, and a nozzle adapted to;de1iver the fluid as a pressure jet to said diifuser vith an ejector action at the rotor end.

12. An elastic fiuidturbine having a hollow shaft at one end thereof, constituting an axial inlet for driving fluid, and a bearing for said shaft equipped With packing means for delivering the driving fluid to said shaft end as a jet, and adapted to create an ejector action in the area around the rotor end With said packing interposed be- GUSTAV EGGER.

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