US2684634A - Guiding means for liquids and gases - Google Patents

Description

A. J. SCHNEIDER GUIDING MEANS FOR LIQUIDS AND GASES July 27,/1/95/4 2 Sheets-SheetA l Filed Feb. 26. 1948 July 27, 1954 A. J. SCHNEIDER GUIDING MEANS FOR LIQUIDS AND GASES 2 sheets-sheet 2 Filed Feb. 26, 1948 V. .la

INVENTOR.

Patented July 27, 1954 GUIDING MEANS FOR LIQUIDS AND GASES August Johannes Schneider, Stafa, Switzerland,

assigner to Socit financire dExpansion Commerciale et Industrielle S. A. Sndex, Sarnen,

Switzerland Application February 26, 1948, Serial No. 11,156 In Switzerland April 16, 1946 Section 1, Public Law 690, August 8, 1946 Patent expires April 16, 1966 4 Claims. l

This invention relates to a novel guiding means for liquids and gases or for mixtures thereof with particles of matter carried along thereby.

The means in question serve to produce or to guide annular flow, in particular in centrifugal engines, such as hydraulic turbines and pumps, gas turbines and ventilators, centrifuges and the like.

The requirements which the guiding means employed in the construction of centrifugal engines must meet are manifold and they must be such as to guide a gas or liquid with a definite tangential component along a solid of revolution. They must in addition form or produce a uniform flow with full admission about the entire circumference and if necessary convert potential energy into kinetic energy and vice-versa.

In addition, it must be possible to vary by means of regulating means the admission and the area of through-flow while maintaining the angle of flow constant, and in certain cases it must be possible to vary at will the tangential component of the flow, hereinafter referred to as the twist, by further regulating means which are separately applied.

With the known guiding means, there is no satisfactory method of fulfilling these requirements simultaneously, and in addition existing constructions, those employing adjustable guide vanes, and the like, have still further constructional disadvantages, such as the multiplicity of the parts to be moved by regulating means, diniculty of packing guide means which are to be actuated by regulating devices, and the clearance losses thereof, compromise by limitation of the number of blades, and so on.

In View of this fact, various attempts have been made to provide guiding means without the disadvantages referred to. In particular, annular slide valves have been proposed with which a greater or smaller area of through-flow is freed by axial displacement of the annular slide valve.

With these arrangements, it was desired to produce the tangential flow by the spiral inflow form the spiral casing, and by providing spirally curved guide surfaces with parallel axes, which were disposed in the path of the inflow directly in front of the annular slide valve. These proposals, however, do not provide the desired constant twist over the entire periphery and for all opening positions, owing to the fact that at the time when the annular slide valve begins to open a more meridional outflow occurs instead of the outow with a predetermined tangential component, at all points where there is no spiral guide surface. Only when the annular valve is fully opened will the tangential component also reach its full uniform degree.

The regulability of the area of an annular flow with full admission over the entire circumference and with constancy of the desired twist is obtained in accordance with the invention owing to the fact that a spiral flow-guiding surface having at least a single thread and with a pitch ranging from approximately but more than zero to approximately but less than degrees, is situated within two surfaces of revolution limiting an annular flow, and that at least annular parts of one flow-limiting surface of revolution can be displaced in the axial direction in order to adjust the area of through-flow.

The invention will be better understood from a consideration of the following description in conjunction with the accompanying drawing, in which:

Figs. l, 2 and 3 show annular nozzles and parts thereof respectively in vertical central section;

Fig. 4 shows in vertical center section of a centrifugal engine.

Figures 1 and 2 show constructional examples of annular nozzles or diliusors in vertical centre section. In these gures, numerals I and 2 and 2" represent the flow-limiting surfaces in section, the area of through-flow being varied by variation of the position of 2 in the direction of the double arrow. 3 is the single threaded or multithreaded spiral surface determining the direction of iiow and in particular the rotational component, in section. It is to be considered as geometrically formed from a spiral movement of a line or-as in the figureof a straight line passing through the axis. According to requirements, it is possible also to make only the part 2 movable, while its extension 2" may be rigidly connected to the remaining part of the guide means. The forward edges of 2 and 2" would then coincide at complete opening. The pitch of the spiral surface and its prole need only be constant in so far as this is necessary with a view to obtaining a constant outlet angle, while it can gradually 3 change to innite outside 2, that is to say within the range of 2". The flow freely leaving in the direction of the arrow has the form of a hyperboloid, the generatrices of which constitute the rectilinear out-flow jets.

The actuation of the annular' slide in Fig. 1 for obtaining the regulating movement may be eifected by turning the turnable but not axially displaceable spindle 3a in the threaded boss la of the annular slide, turning motion of the latter being prevented by the spline 3a which permits an axial movement of the slide only. rlhe spindle tia is turned by means of bevel-wheels so; and a handwhecl ma.

A further mode of actuating the annular slide 2 is diagrammatically shown in Fig.2 by wayof example and comprises a hydraulic means. In this design the position of the annular slide is determined by the position of the lever'ZJ provided with a pawl 2| which cooperates with notches provided in a guidance -22for the lever, and engages a notch corresponding to-the desired position of the annular slide. Upon a' displacement of the lever the pin 23 on the latter, which is guided in a fork 23, turns the fork 2li pivoted'at 25 toward the right or the left. By this turning motion of the fork the piston 26 in the cylinder 21 is displaced by a certain amcunt'to the rightV or the left. If the piston 26 is moved towards the right by a lifting motion of the lever the annular chamber 28 is connected Vvia the tube 29 and the tube 30 with the water under pressure derived 'in front of the annular nozzle. The water pressure in the chamber 23 causes a lifting of the annular slide until after the lever 20 has returned into its horizontal position or, respectively, until the pin 2S,l theforlrsand the piston 23 have been returnedinto their medium positions. The reverse vdisplacement of the lever 20 in the downward position causes movements which are opposite to those'described above and the annular chamber is connected to the outlet 3l for the pressure water. The slide valve is lowered until the desired position depending on the adjustment of the lever 2li by' pawll and notch is reached.

Figures l-and 2 show the application of the guiding :means as an annular nozzle for converting pressureenergy into velocity-energy, Figure l shows an annular flow directed inwardly with respect to the and Figure 2 an annular flow directed outwardly with respect to the axis.

`When the ow is reversed, and thus is opposite to the direction of the arrow Il, the guiding means work as diifusors, that is to say they convert velocity into pressure energy, in opposite directions-outwardly in Figure 1 and inwardly in Figure 2.

lInFigures 1 and 2, the cross sectional area of the annularl flow has been regulated by a cylindrical control member exactly at the outlet from'the spiral flow-guiding surface 3 (and in the case of reversal of the direction of ow at the inlet into the said spiral surfaces), and consequently the admission to the guiding means has been altered while the outlet and inlet angles have been maintained constant.

However, if the area of through-flow is narrowed by a further regulating member situated at a certain distance outside the spiralsurfaces guiding the annular ow, a possibility is provided of reducing or regulating the tangential component of the annular flow by further regulating means additionallyl applicable.

Figure 3 shows, by way of example, in contrast Awheels V34 and 35.

to Figure 1 an additional regulability of the tangential component or of the twist of the annular flow set up. In Figure 3, numeral 5 refers to the control member for varying the annular area of through-flow outside the range of the spiral flow-guiding surfaces.

When the control member 5 is completely withdrawn and the area is completelyfreawthe maxiymum twist produced by the'spiral surface will be present as the uid leaves the guide means.

However, in proportion as the area is narrowed by 5 the iilaments of the stream will be deflected in a meridional direction. In the extreme case, directly before -the `annular outlet aperture is `closed by the control member 5, the tangential component of .the filaments will be equal to zero and l will'be a meridional out-ow.

The displacement of the control members or .annular slides '2 and 5 may be effected, as is '5 isdesired for varying the through-now area the clamping device 4l is tightened so that both hand wheels turn together. If, however, a displacement of the annular slide 2 relative'to 5 is desired for varyingthe tangential component, the clamping device 4i is lifted'andthe screw rwheel 34 is turned by turning thei hand wheel 38, whereas the hand wheel 33 is kept stationary.

Figure i shows an'example of the embodiment of the new annular-flow guiding means for centrifugal engines, wherein the function of 'the flow-limiting surface of revolution off one guiding means-with its control edge determining the area of through-'flow is taken over by the other guiding means rotating relatively thereto, owing'toa suitable series arrangement of guiding vmeans rotating in opposite direction tooneianother.

Figure 4 shows,l by way of example, acentrifugal engine which can be employedeither as1a pump or as a turbine. When itis employed as a pump, '6 (Figure Av4) constitutesafxed outwardly directed annular nozzle,as in Figure 2, as an entrance for 'the transition of the suction pipe into the rotor-part. Situated abovethis annular 4nozzle is the cylindrical, also fixed-guide memberB.

-Mounted over 31 and S in the manner of a -bell is the rotor --with` its lower-cylindrical guide surfaces'fand 9,-its lower flow-limiting surface of revolution E0 of saddleshape, its'fow-guiding surfaces H, itsupper flow-limitingrotary surface of revolution 2,5the upper cylindrical guide surfaces I3v and'lS, itshub t4 vand the shaft l5. Mounted on the xedfcasing i5 is the'distributor il, whichagain constitutes a guide means similar to that shown in Figure 1, except that the axial delivery `and discharge here take place through a spiral pipe i3. Referring again tothe function of the annular nozzle B-in the `case-of a pump (similarto that shown in'Figure 2), it is to be noted thaty the function off-the annulaicontrol meniber-'Yl adjusting the area ofthroughnow (Figure-2) isi-n'thisicase takenfover :by'a partof the rotor, .namely the inner guide surface 9., and that the entire rotor is axially displaceable together with the shaft l5 to carry out the adjusting movement. The same applies to the distributor Il, corresponding to an annular diffuser as shown in Figure l, which is here adjusted by the guide surface Q rotating with the rotor, instead of 2 (Figure l). 9 is therefore also adjusted by the same axial displacement of the rotor simultaneously with 9, so that all conditions of opening can be achieved simultaneously at all points of transition between the suction pipe and the rotor, and also between the rotor and the distributor merely by axial displacement of the rotor, the inlet and outlet angles being maintained constant.

The aforementioned axial displacement of the rotor may for example be effected by hydraulic means, diagrammatically shown in Fig. 4, by admitting water under pressure to the annular space 42 or respectively by letting the water escape from that space. To that endL a movement of the valve piston 43 in the cylinder 44 towards the left, in Fig. 4, causes the annular space 42 to be supplied with water under pressure from the spiral tube I8 via the supply pipe 45, Whereas the opposite movement of the valve piston connects the annular space y42 via the pipe 46 to the suction tube.

A means has thus been found for the first time of providingthe possibility, so desirable in hydraulics, of so regulating the areas of throughflow through the centrifugal engine with strict accuracy from both the hydraulic and the solid geometric viewpoint that the tangential components of the flow at the inlet to and the outlet from the runner wheel are so constant that impact losses and losses due to residual twist at the outlet from the centrifugal engine are absolutely avoided over any load range and under any opening conditions of the centrifugal machine.

It will be readily understood that the adjustment by axial displacement of the rotor is mechanically substantially simpler and much more efficient than the known adjustments with centrifugal engines, for example the adjustment by means of adjustable guide varies, not to mention the throttling down of pumps by means of regulating slide valves. A further advantage of the type of pump according to the invention is that if the pump is connected to a pipe system under pressure the danger does not arise of the pump entering the so-called unstable range of the load diagram, as do pumps with forward or radial discharge from the runner wheel.

This unstable condition in the delivery pressure from the moment when a pump is started up arises owing to the fact that the pump at rst runs with the slide valve closed, that is to say, with zero through-flow. There is thus set up at the outer edge of the rotor a pressure corresponding to the centrifugal action of the rotating liquid ring in the rotor, while the actual pressure of the conveying pump is still higher by the degree of velocity times the efficiency of the distributor-diffusor.

The type of pump according to the invention on the other hand, can start with the slide valve open but with the rotor set at zero through-now and therefore starts to deliver immediately the areas of through-now are freed by axial displacement of the rotor, with the full dynamic pres- 16 sure set up by the velocity conversion in the diffuser.

The flow-guiding surfaces ll, that is to say, the blades of the rotor, are shown by way of example in Figure 4 as pure radial surfaces. In profile, they iill the space between the flow-limiting surfaces Il) and I2. The inlet edges of these blades (in the case of a pump) lie in the cylindrical limiting surface of the inner jacket of the rotor (continuation of the guide surfaces 8 andy i3), while the outlet edges lie in the cylindrical limiting surface of the outer jacket of the rotor (continuation of the guide surfaces 9 and I 3').

I claim:

l. Guiding means for annular flow of liquids in rotary engines, comprising at least one thin now guiding helical surface, two surfaces of revolution enclosing said helical surface for limiting an annular flow, a further surface of revolution, and means to axially adjust at least annular portions of one of said two limiting surfaces to effect a variation o-f the throughlow, and to adjust said further surface of revolution to eiect a variation of the tangential component of the flow, the whole in such combination that a perfect throughow with a minimum of losses is achieved.

2. A rotary pump having a runner and a discharge-guide-apparatus, said apparatus being provided with guiding means for annular flow, which means comprise two surfaces of revolution for limiting an annular flow and helical surfaces having at least one thread arranged between said surfaces of revolution, means for causing a relative axial displacement between said runner and discharge-guide-apparatus, a rst control edge provided at the outlet of said runner and causing a regulation of the outlet angle of flow into said discharge-guide-apparatus upon said axial displacement and a second control edge provided on one of said surfaces of revolutions of the discharge-guide-apparatus and causing a regulation of the discharge cross-section from said runner upon said axial displacement.

3. A turbine having a guide-apparatus and a runner, said guide-apparatus being provided with guiding means for annular flow, which means comprise two surfaces of revolution for limiting an annular flow and a helical surface having at least one thread and being arranged between said surfaces of revolution, means for causing a relative displacement between said guide-apparatus and said runner, a rst control edge provided on one of said surfaces of revolution of said guide-apparatus and causing a regulation of the entrancecross-section into said runner upon said axial displacement, and a second control edge provided on said runner and causing a regulation of the outlet angle of flow of said guide-apparatus.

4. A turbine having a suction tube and a runner, said suction tube being provided with guiding means for annular flow, which means comprise two surfaces of revolution for limiting an annular now and a helical surface having at least one thread and being arranged between said surfaces of revolution of said guiding means, means for causing a relative displacement between said suction tube and said runner, a rst control edge provided on said runner and causing a regulation of the entrance angle of now into said guiding means, and a second control edge on one of said surfaces of revolution of said guiding means and causing a regulation of the dischargecross-section from said runner.

(References on following page) References Gite'd .in f.. the-f lef of `fthsz patent UNITED STATES PATENTS Number Name Date Truax Jan.17, 1871 Wright Mar. 23, 1897 Mader Oct. 18, 1910 Junggren May, 1911 Johnson July 15, 1924 Price Nov. 26, 1929 Krgan vJuly 7, 1931 Legrand Dec. 8,. 1931 Bencowtz et al. July 28, 1936 UNumber Number 10 60,353

8 `Name Date Vollmer Nov. 28, 1939 Andler .July 2, 1940 Hann Mar. 2, 1943 YHasbrouck Nov. 25, 1947 Pulver Aug. 15, 1950 FOREIGN PATENTS Country Date France Oct. 5, 1863 (2nd Ser., Vol. 86, page 3, p1. 2) Switzerland Apr. 15, 1951

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