US3032313A

US3032313A - Turbo-machines

Info

Publication number: US3032313A
Application number: US649666A
Authority: US
Inventors: Szydlowski Joseph
Original assignee: Bertin et Cie SA
Current assignee: Bertin Technologies SAS
Priority date: 1956-04-09
Filing date: 1957-04-01
Publication date: 1962-05-01
Anticipated expiration: 1979-05-01

Description

May 1, 1962 J. SZYDLOWSKI 3,032,313

TURBOMACHINES Filed April 1, 1957 2 Sheets-Sheet 1 May 1, 1962 J. SZYDLOWSKI 3,032,313

TURBO-MACHINES Filed April 1, 1957 2 Sheets-Sheet 2 I l a l 7 24 v .8 5 .25 1 I I :1 -u

United States Patent ()fitice 3,032,313 Patented May 1, 1962 3,032,313 TURBO-MACHINES Joseph Szydlowski, Bordes, France, assignor to Societe Bertin & Cie, Paris, France, a corporation of France Filed Apr. 1, 1957, Ser. N0. 649,666 Claims priority, application France Apr. 9, 1956 3 Claims. (Cl. 253-39) In piping systems or conduits traversed by fluids, it has already been proposed to form a divergent portion of such a piping system or such a conduit by a fluid layer generated by the expansion of an auxiliary fluid under pressure, in a nozzle in the form of a suitably-directed slot which is formed on the solid Wall, in the zone at which the divergence of the conduit is to begin.

The present invention relates to the application of such fluid divergents to the channels of turbo-machines (such as compressors, pumps or turbines) and has for its object to permit of the replacement, at least in part, of the usual solid blades of these machines by oriented fluid layers.

In actual fact, the grids of blades of compressors or pumps and sometimes of turbines frequently comprise divergent sections of passage, especially on the stators or rotors of compressors and on the exhaust rectifiers. of turbines.

In all these cases, the solid blades or vanes of the usual type are advantageously replaced in the present invention, by several series of suitably-directed fluid screens produced by means of nozzles in the form of slots oriented in the desired sense on truncated vanes distributed about the rotation axis of a turbo machine and having an axial length less than the corresponding axial sections of the rotor or stator in which they are disposed. These slots form nozzles. The truncated vanes or b'ades are restricted to a leading portion of the vane and the fluid discharged therefrom through said nozzles form extensions of the vanes effective to eflect energy transfer with the main fluid stream flowing through the turbo machine supplied with auxiliary fluid under pressure from an appropriate source.

The auxiliary fluid may be of any kind, liquid or gaseous, as may also the principal fluid which passes through the turbo-machine. In general, there will be employed as the auxiliary fluid aderivation of the main fluid taken at a point of its circuit at which it has a suflicient pressure, for example at a downstream stage in the case of a compressor with a number of stages.

" .The auxiliary fluid, whatever its origin may be, may be pumped or compressed by means of accessory apparatus adapted for that purpose.

The description which follows below with reference to the accompanying drawings (which are given by way of example only and not in any sense by way of limitation) will make it quite clear how the invention may be carried into effect, the special features which are brought out, either in the drawings or in the text, being understood to form a part of the said invention.

FIG. 1 is a developed view of the blades of the usual type or rotor and stator of an axial compressor;

FIG. 2 shows the use of fluid screens in replacement of the blades of the stator;

FIGS. 2a, 2b, and 2c are diagrams of speeds of How through the stator of FIG. 2;

FIG. 3 is a diagrammatic view in elevation, showing a slot and its support;

FIG. 3A, is a vertical sectional view illustrative of an embodiment in which fluid is provided to rotary vanes of a rotor;

FIG. 4 shows an alternative form in which both the driving blades and the guiding blades of the compressor are constituted by fluid screens; and

FIG. 5 is a diagrammatic view illustrative of the application of the invention to a diffuser of a centrifugal compressor.

The developed view of FIG. 1 shows a typical example of a stage of an axial compressor with its driving blades M and its fixed guiding blades D which are both formed of solid profiled vanes 1 and 2. This assembly may be repeated along the circuit of the active fluid to be compressed in the case of compressors having a number of stages. The active fluid circulates from left to right; it passes into the rotor M, the direction of rotation of which is indicated by the arrow 1'' and passes out of the stator D.

In the form of embodiment of the invention shown in FIG. 2, the rear portion of the solid guiding blades 2 which define divergent channels, is replaced by fluid screens 3. In th s case, FIG. 3, the solid elements of the guiding blades D are hollow members or truncated vanes reduced to the front portion 4 of the blades. These portions are hollow and have a substantially flat high pressure side and an arcuate low pressure side and each have a tapered leading edge and a blunt downstream edge portion. They act as supply collectors for nozzles 5 dis-. posed closely adjacent the blunt edge on the downstream edge portion. The nozzles are formed by radially elongated openings having the form of narrow slots having a radial length approximately the height of each element 4. These slots open to the high pressure side and are suitably directed in order that the fluid which is discharged through them can produce the fluid screens de-. sired. Pressure fluid is supplied internally of the blades through a radial opening 6 in the housing 11, in com munication with a manifold 12 connected to a conduit 12 through which the fluid is supplied either from a separate source or from the main fluid.

When the flow is considered at the outlet of the blades 1 of the rotor, this possesses components of speed similar to those which are shown in FIG. 2a, in which V is the absolute speed. V is the tangential component and V is the axial component.

The supports 4 of the slots 5, by reason of their shape similar to the front portions or leading portions of blades, modify slightly the triangle of speeds (see FIG. 2b); the tangential component V becomes V which is smaller, the axial component V becomes V which is slightly greater, whilst the absolute speed V becomes V which is smaller as a result of the increase of the sections which may be due either to the change in the mean angle tangential component mV (see FIG. 2c) where 'm' and m are the output-masses respectively of the whole of the fluid screens and the principal flow.

In order to cancel this tangential component mV then mV should be substantially equal to m'V' the direction of the speed V of injection of the auxiliary jets being in addition substantially tangential and opposite to the direction of rotation of the rotor f. This is brought out in FIG. 20, in which the lengths of the vectors represent the momentums mV 111V; and mV and are proportional to the lengths of the corresponding vectors of FIG. 2b; from which the resultant is mV The final resultant mV is smaller than mV by reason of the increase in pressure, but it has the same direction as this latter.

The invention also provides for applying fluid to the blades or vanes that are capable of rotating. Thus, in FIG. 3A is illustrated an embodiment of the invention in which hollow rotary vanes 4 are connected to a hollow shaft 7 by means of hollow support means 8. These blades are provided with nozzles 5 disposed on the vanes as heretofore described with respect to FIG. 3.

Internal fluid is applied to the interior of the blades through the hollow shaft 7- having radial openings communicating with a channel 9 on the supporting means 8. Fluid enters the vanes through openings 10..

FIG. 4 shows an arrangement similar to that of FIG. 2, but in this case fluid screens 3 are utilised both for the rotor and for the stator. The driving blades are constituted by supports 4' provided with slots 5' which produce fluid screens 3 having a suitable direction. The supply of the slots 5 with auxiliary fluid may be eflected by taking advantage of the centrigugal forces set up, the fluid being admitted through orifices located in the vicinity of the axis of the rotor in the manner of the embodiment in FIG. 3A.

It should be noted in the case of a rotor with fluid blades of this kind, that in consequence of the orientation of the slots 5' in the direction of rotation 1, there is produced a reaction effect tending to act in opposition to the rotation of the rotor and giving rise for that reason to extra work in order to effect that rotation; this increase in driving work shows itself in the principal flow by a work of compression.

FIG. 5 shows an assembly equivalent to that preceding,

in the case of a diffuser of a centrifugal compressor, the rotor of which is shown at R. The fixed blades are constituted by supports 4" provided with slots 5" directed. at an angle a, with the radius in a direction substantially tangential and opposite to the direction of rotation f.

It will of course be understood that modifications may be made to the forms of embodiment which have just been described, in particular by the substitution of equivalent technical means, without thereby departing from the scope of the present addition.

What is claimed is:

1. A turbo machine of the axial flow type having cooperative rotor and stator sections in energy transfer relation with a main fluid stream flowing therethrough, at least one of said sections comprising a plurality of angularly spaced hollow members distributed about the rotation axis of said axial flow type turbo machine and c nstructed' in the form of radially extending truncated hollow vanes restricted to a leading portion, each vane having a substantially flat high pressure side and an arcuate substantially convex low pressure side and each having a tapered leading edge and a blunt downstream edge portion, each truncated hollow vane having an axial length substantially less than the axial length of said section in which the vanes are disposed, each of said hollow vanes having a narrow, radially elongated opening forming a nozzle closely adjacent said blunt edge on said downstream edge portion and disposed opening to said high pressure side, means for supplying internally of said vanes pressure fluid discharged in operation out of the respective nozzles of said hollow vanes as jet-streams to form individual sheet-like streams of pressure fluid, and each nozzle having a radial length and a width dimension selected to cause said streams to correspond to fluid extensions of the respective hollow vanes to form for each hollow vane a trailing portion and each disposed to cause said pressure fluid to issue in operation into said main fluid stream and thereby in conjunction with a given respective leading portion act as a complete vane in transferring energy.

2. A turbo machine of the axial flow type having cooperative rotor and stator sections in energy transfer relation with a main fluid stream flowing therethrough, at least one of said sections comprising a plurality of angularly spaced hollow members distributed about the rotation axis of said axial flow type turbo machine and constructed in the form of radially extending truncated hollow vanes restricted to a leading portion, each vane having a substantially flat high pressure side and an arcuate substantially convex low pressure side and each having a tapered leading edge and a blunt downstream edge portion, each truncated hollow vane having an axial length substantially less than the axial length of said section in which the vanes are disposed, each of said hollow vanes having a narrow, radially elongated opening forming a nozzle closely adjacent said blunt edge on said downstream edge portion and disposed opening to said high pressure side, means for supplying internally of said vanes pressure fluid discharged in operation out of the respective nozzles of said hollow vanes as jet-streams to form individual sheet-like streams of pressure fluid, and each nozzle having a radial length and a width dimension selected to cause said streams to correspond to fluid extensions of the respective hollow vanes to form for each hollow vane a trailing portion and each disposed to cause said pressure fluid to issue in operation into said main fluid stream and thereby in conjunction with a given respective leading portion act as a complete vane in trans-' ferring energy, and said nozzles being disposed for discharging said sheet-like jet-streams in a direction creating a reaction efiect tending to oppose rotation of said rotor.

3. A turb'o machine of the axial flow type having cooperative rotor and stator sections in energy transfer relation with a main fluid stream flowing therethrough, a

section on said rotor and a next axially adjacent section on said stator each comprising a plurality of angularly spaced hollow members distributed about the rotation axis of said axial flow type turbo machine rotor and constructed in the form of radially extending truncated hollow vanes restricted to a leading portion, each vane having a substantially flat high pressure side and an arcuate substantially convex low pressure side and each having a tapered leading edge and a blunt downstream edge portion, each truncated hollow vane having an axial length substantially less than the axial length of said section in which the vanes are disposed, each of said 'hollow vanes having a narrow, radially elongated opening forming a nozzle closely adjacent said blunt edge on said downstream edge portion and disposed opening to said high pressure side, means for supplying internally of said vanes pressure fluid discharged in operation out of the respective nozzles of said hollow vanes as jet-streams to form individual sheet-like streams of pressure fluid,

and each nozzle having a radial length and a width dimension selected to cause said streams to correspond to fluid extensions of the respective hollow vanes to form for each hollow vane a trailing portion and each disposed to cause said pressure fluid to issue in operation into said main fluid stream and thereby in conjunction with a given respective leading portion act as a complete vane in trans"- ferring energy.

References Cited in the file of this patent UNITED STATES PATENTS 2,344,835 Stalker Mar. 21, 1944 2,408,788 Ludington et a1. Oct. 8, 1946- 2,630,965 Greatrex et a1 Mar. 10, 1953 2,763,427 Lindsey Sept. 18, 1956 2,825,532 Kadosh et al. Mar. 4, 1958 2,830,754 Stalker Apr. 15, 1958 2,935,245 McDonald May 3, 1960 2,944,729 Foley July 12, 1960 FOREIGN PATENTS 586,010 Germany Oct. 14, 1933 has.