US2253530A

US2253530A - Device including receiving elements fed by compressed gas generators

Info

Publication number: US2253530A
Application number: US251861A
Authority: US
Inventors: Pescara Raul Pateras
Original assignee: Individual
Current assignee: Individual
Priority date: 1938-01-28
Filing date: 1939-01-19
Publication date: 1941-08-26
Anticipated expiration: 1958-08-26

Description

Au 26, 1941. R. PATERAS PESCARA 2,253,530

DEVICE INCLUDING RECEIVING ELEMENTS FED BY COMPRESSED GAS GENERATORS Filed Jan. l9, 1959 S-Sheets-Sheet 1 J12 -5 Tl In (lento .Bzul .Zkieraa 1%.564 rag;

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DEVICE INCLUDING RECEIVING ELEMENTS FED BY COMPRESSED GAS GENERATORS Filed Jan. 19, 1959 3 Sheets-Sheet 2 DEVICE INC LUDING RECEIVING ELEMENTS FED BY COMPRESSED GAS GENERATORS Filed-Jan. 19, 1939 asheets-shet 3 fizuZ jjeras fiacara, I

mQg w another system;

' 1 system according to the invention; A

Patented Aug. 26, 1941 DEVICE INCLUDING RECEIVING ELEMENTS I FED BY COMPRESSED GAS GENERATORS ItaulPateras Pescara, Paris, France Application January 19, 1939, Serial No. 251,861 In liiuxemburgv January 28,1938

14 Claims.

The present invention relates to devices including receiving elements fed by compressed gas generators, and it is more especially, although not exclusively, concerned, among these systems, with those in which the compressed gas is fed by a free piston generator (that is to say a compressed gas generator the piston of which moves with a variable stroke) this generator being characterized by the fact that it cannot be mechanically synchronized or regularized by means of a fly-wheel.

The object of the present invention is to provide a system of this type which is better adapted to-meet the requirements of practice than those used for this purpose up to the present time. v

- According to an essential feature of the present invention, the system of the type above referred toincludes at least one receiving element fed with compressed gas by. at least one generator connected to said receiving element through a discharge manifold, at least one cushioning or absorbing chamber connected to said manifold, and means, interposed between said manifold and said cushioning chamber, for temporarily and at least partly bringing out of action said absorbing chamber in the case of variations of the mean pressure in said manifolclwhich areof relatively high amplitude.

According to'another feature of the present invention, the compressed gas generator is a free piston auto-generator, that is to saya free piston machine in which at leasta portion of the compressed gas is utilised for the scavenging and feeding of the motive portion of the system, and,

in order to absorb, up to a point, the pressure variations in the discharge conduit and in the scavenging air reservoir of said generator, I provide, between these two spaces, at least one movablewall capable of moving, under the effect of said pressure variations, in such manner as to produce opposed variations of the volumes of said spaces.

Other features of the present invention will result from the following detailed description of some specific embodiments thereof.

Preferred embodiments of the present invention will be hereinafter described, with reference way of example, and in which:

Fig. 4 is a. diagrammatic sectional view of a first embodiment of a system made according to the present invention;

Fig. 5 is a similar view of another embodiment of the invention;

Fig. 4' shows a modification of the arrangement ofFig. 4;

Fig. 6 shows a modification of some elements of the system of'Fig. 5. v

In the following description, that it is desired to provide a. system including at least one receiving machine, such as a turbine '1,

fed with compressed gas by at least one enerator,

or, preferably, several free piston generators such as shown at A and A", said generators being con- ;i810dted to the turbine through a common mani- Generators A and A feed gas under pressure during only a portion of their period of oscillation, 50 that, as a rule, it would be advisable if convenient to adjust-these generators in such manner that their discharge periods are substantially equidistant, in order to avoid sudden variations of pressure in said manifold C.

.However, it may happen that, for accidental causes, such as variations of one of the factors of operation, one of these generators has its working conditions modified. -In this case, there are, for generators A and A, common discharge periods during which instantaneous over-pressures occur,which are advantageously to be absorbed, at least partly, these over-pressures averaging, for instance, half an atmosphere.

On the other hand, if I choose, as factor for regulation of the power of generators A and A (as itis advantageous to do) the variations. of

. mean pressure in manifold C, corresponding to variations of load of turbine T, it is of advantage to have these variations (which maybe as high as several atmospheres) take place as rapidly as possible;

' teristics of the volume of manifold C.

' to the accompanying drawings, given merely by Fig.1 is a diagram illustrating the operation of a system of the kind with which the present in vention is concerned;

.Fig. 2 is a similar, diagram corresponding to Fig. 3 is a similar diagram corresponding. to a As a matter pf fact, if this'manifold is made of considerable volume (case of the diagram of Fig. 1) the instantaneous pressure variations are absorbed in a satisfactory manner but the passage from a mean pressure 111 to a mean pressure pa will call for a relatively longtime, which will delay the regulation of the generators the more as the variation of mean pressure that is considered is more important.

On the contrary, if said manifold is made of a smaller volume (case of the diagram of Fig. 2)

it will be supposed the final pressure 122 is indeed obtained after a time interval is smaller than h, but the instantaneous pressure variations keep an amplitude that is hardly admissible.

According to the present invention, these two conditions can be complied with simultaneously in the following manner:

on the one hand, I provide, in shunt with manifold C, at least one cushioning chamber V, capable of absorbing, at least partly, and temporarily, those of the mean pressure variations which are of little amplitude and result, in particular, from a bad phase interval between generators A and A On the other hand, I provide means for bringin; out of action this cushioning chamber, temporarily and at least partly, in the case of mean pressure variations of large amplitude, that is to say variations which would oppose a good regulation of said generators.

The pressure variations in manifold C corresponding to a variation of the load of turbine T, will then follow a law corresponding to the diagram of Fig. 3 and the characteristics of which are the following:

When the mean pressure is 12;, chamber V acts in order to absorb the variations of the instantaneous pressure. As, soon as the load of the turbine varies, said chamber is insulated, or separated, from manifold C, so that the instantaneous pressure variations again assume their own amplitude, but the new pressure pz is obtained in a time t'2 which permits a quick regulation.

When chamber V is brought back into action, after time t'i, these instantaneous pressure variations are again absorbed by the new mean pressure m which exists in manifold C.

I will first describe how generators A and A are made.

Their general structure may be of any kind, either conventional or not. For instance, as shown by the drawings in a diagrammatic manner, they include a driving piston l rigid with a compressor piston 2 movable in a cylinder 3, said piston drawing in air from the atmosphere through a valve 4 and discharging it, through a valve 5 and a conduit 6, into a driving cylinder I from which the gaseous mixture under pressure is fed, through a pipe 8, corresponding to each generator, into a common manifold C.

These generators are provided with a device for regulating their working as a function of the mean pressure in said manifold C. This regulating device is made in any suitable manner, either conventional or not. For instance, as shown. by Fig. 4, the discharge of the injection pump 9 of these generators is regulated through a cam IU of suitable shape, controlled by a piston ll, movable against the action of a spring I2 in a cylinder l3 in which the pressure is equal to said mean pressure. The whole is arranged in such manner that the discharge of pump 9 increases simultaneously with this mean pressure.

Concerning now the means to be provided for preventing chamber V from retarding the regulating action of mean pressure variations in mansuch manner that, by a device the displacements of which correspond to variations of the mean pressure, when said mean pressure changes (generally, as it will be hereinafter supposed, as a result of variations of the working conditions of tubine T) the section of flow between chamber V and manifold C is varied, being eventually reifold C, they can be constituted, for instance, ac-

cording to one of the arrangements which will be now described.

According to the first of these arrangements.

which is shown by Figs. 4 and 4, chamber V and manifold C are caused to coact directly with one duced to zero.

In particular, according to theembodiment illustrated by Fig. 4, I make use of a movable partition, consisting, for instance, of a piston 50 movable in a cylinder 5|, updn the respective faces of which the variations of the mean pressure in manifold C act after different time intervals.

In this embodiment, shutter I4 is connected to the rod 52 of said piston, which is subjected to the action of springs 53 and 53' adapted to bring it back into an intermediate position.

The ends of cylinder 5| are connected respecively to manifold C through a conduit 54 of large section and to chamber V through a calibrated conduit 55', said chamber being itself connected to said manifold through a calibrated conduit 55.

With such a device, any sufliciently strong variation of the mean pressure in manifold C will produce a displacement of piston 50 which brings shutter l4 into the closing position I or into position II, according as there is a reductionor an increase of the mean position. This shutter will then remain closed until the pressures on the respective faces of said piston are again balanced through conduits 55 and 55'.

According to another embodiment of the inven tion, illustrated by Fig. 4, shutter I4 is controlled through a centrifugal device operated in accordance with the working of turbine T.

In this case, preferably, the variations of large amplitude in the working conditions produce the full closing of shutter M, the latter remaining closed until, the regulation having been effected, the turbine is again working under normal conditions corresponding to a new value of the mean pressure in manifold C.

It is possible, for instance, for this purpose, to connect shutter H, through the intermediate of a rod I5 and a lever IS, with a centrifugal device 11 the movable sleeve of which carries a collar I8 adapted to coact with a fork l9 provided at the end of said lever IS, the whole being arranged in such manner that, when said collar moves on one side or the other of its mean position (said mean position corresponding to normal running of the turbine and to full opening of shutter l4), said shutter comesinto position I or position II, according as the speed of turbine T increases or decreases.

It should be noted that, as a rule it is advantageous to leave a certain play between collar I8 and fork l9, this play corresponding to small variations of speed of the turbine for which it is not necessary to, act on the generator regulating system.

The operation of such a device takes place as follows:

Every time there is a variation of some importance of the load of turbine T, that is to say a temporary perturbation of the working of said turbine, chamber V is separated from manifold C. When'a final regulation of generators A and A has been obtained, turbine T comes back to normal working conditions, producing the opening of shutter I4, and consequently a partial absorbing of said mean pressure variation. From this time on, chamber V, which is at a pressure equal I that of practically protecting the turbine against to the stabilization value of the mean pressure, will be capable of again ensuring an absorption of small variations of the instantaneous pressure.

In the embodiment illustrated by 'Fig. 5, the means above mentioned are made in a difierent manner. In this case, chamber V and manifold C no longer cooperate directly together but there is interposed between them a structure including,

for instance, a chamber 26 of cylindrical shape which may constitute at least a'portion of chamber V and serves to connect it to said manifold, and a movable partition of low inertia, such for instance as a membrane or better a piston 21, capable of moving, between abutment's 22 22, against the action of springs 2'3 and 23' which tend to return it to its intermediate position.

Preferably, the strength of springs 23 and 23' is relatively low so thatthe instantaneous varie tions of pressure, which, for instance, average half an atmosphere, are sumcient for displacing said piston 2i as far as its end positions.

Thus, the displacements of piston M will be limited for important variations of the mean pressure in manifold C, corresponding to the piston being" brought into contact with pieces 22 and 22', which separates chamber V from manlfold C, and permits of a new value of the mean pressure being established in said manifold as above explained.

It should be noted that, advantageously, the amplitude of the maximum displacements of piston 2| from its position of equilibrium is independent from the value of ,the mean pressure in manifold C. For this purpose, for instance, said manifold communicates with chamber V through the intermediate of a conduit 24 which is preferably of reduced section, so that the variations of mean pressure in manifold C take place but gradually in chamber V- (curve a of the diagram of Fig. 3).

According to still another embodiment of the "invention, illustrated by Fig. 6, I make use, for

controlling'the displacements of piston 28, of a servo-motor, for instance a' hydraulic one, responsive to variations of relative pressure between manifold C and chamber V. I

Advantageously, this servo-motor is made as follows:

I couple with piston 2| a. balanced piston 25 toward one or the other face of which a liquid under pressure canbe fed through a distributor 28.

Said distributor is controlled by a balanced pis- I top 21 one of the faces of which is subjected to the action of the pressure in manifold C through a conduit 28, and the other face of which is subjected to the action of the pressure in chamber V through a conduit 29, the whole being arranged in such manner that the increases of instantanecus pressure in manifold C produce, through the intermediate of the servo-motor, a displacement of piston 2 l tending to increase the volume of said manifold. I connect the end of C through a conduit .24 by means of which it is possible gradually to obtain the-equality of the respective faces of piston 2|,

pressures on the through the medium of conand, furthermore,

duit 29, on the respective faces of piston 21.

Whatever be the particular embodiment that is chosen, I obtain a generator-turbine system the operation of which results sufilciently clearly from the above description for making it unnecessary to give further explanations. Furthermore, this device has, among other advantages,

cylinder 20 with manifold description, disclosed what I deem to be practical and efllcient embodiments of the present invention, it should be well understood that I do not wish to be limited thereto as there might be changes made in the arrangement, disposition and form of the parts without departing from the principle of the present invention as comprehanded within the scope of the appended claims.

What I claim is:

1. A system of the type described, which comprises, in combination, a receiving machine, at least one generator for feeding fluid intermittently to said machine, a manifold connecting said generator with said receiving machine, a pressure regulating structure forming a chamber connected to said manifold, and pressure responsive means for temporarily and at least partly bringing said regulating structure out of action inresponse to pressure variations in said manifold exceeding a predetermined value.

2. A system of the type described, which comiprises, in combination, a receiving machine, at least two free piston generators for feeding gas under pressure intermittently to said receiving machine, a manifold connecting said generator with said receiving machine, a pressure regulating structure forming a chamber connected to said manifold, and means, responsive to pressure variations in said manifold exceeding a given value, for bringing said regulating structure at least partly out of action temporarily while said pressure variations take place.

3. A system of the type described, which comprises, in combination, a receiving machine, at

,least one generator for feeding fluid intermittently to said machine, a manifold connecting said generator with said receiving machine, a

pressure regulating structure forming a chamber connected to said manifold, valve means between said manlfold and said chamber, and means, responsive to differences of pressure between said manifold and said chamber exceeding a given value, for actuating said valve means so as temporarily and at least partly to cut off the I connection between said manifold and said chamber under the effect of pressure variations in said manifold exceeding a predetermined value.

4. A system of. the type described, which comprises, in combination, a receiving machine,- at

least one generator forfeeding'gas under presthe opposed actions of the pressure in said mani-' fold and the pressure in said chamber, and means for coupling said valve means with said piston so that said valve means are at least partly closed when a sudden pressure variation occurs in said manifold.

5. A system of the type described, which comprises, in combination, a receiving machine, at least one generator for feeding gas under pressure intermittently to said receiving machine, a manifold connecting said generator with said receiving machine, a pressure regulating structure forming a chamber connected to said mani fold, a conduit of large section extending besaid piston so that said valve means are at least partly closed when a sudden pressure variation exceeding a given value occurs in said manifold.

6. A system of the type described, which comprises, in combination, a receiving machine, at least two free piston generators for feeding gas under pressure intermittently to said receiving machine, a manifold connecting said generator with said receiving machine, means responsive to pressure variations in said manifold for regulating said generator, a pressure regulating structure forming a chamber connected to said manifold, and means, responsive to sudden pressure variations in said manifold exceeding a predetermined value, for bringing said regulating structure at least partly and temporarily out of action while said sudden variations take place.

7. A system of the type described, which comprises, in combination, a receiving machine, at least one generator for feeding gas under pressure intermittently to said receiving machine, a

manifold connecting said generator with said receiving machine, a pressure regulating structure forming a chamber connected to said manifold, a passage of relatively large section between said manifold and said chamber, a movable wall forming a partition in said passage, and abutment means for limiting the displacements of said wall, so as to separate said chamber from said manifold and to stop pressure transmission from one to the other when sudden pressure variations exceeding a predetermined value occur in said manifold.

8. A system of the type described, which comprises, in combination, a receiving machine, at least one generator for feeding gas under pressure intermittently to said receiving machine, a manifold connecting said generator with said recciving' machine, a pressure regulatingstructure forming a chamber connected to saidrmanrfold, a passage of relatively large section between said manifold and said chamber, a piston movable in said passage, spring means for urg ng said piston toward an intermediate posit1on, abutment means for limiting the displacements of said piston in both directions, so as to stop transmission of pressure variations from said chamber to. said manifold and inversely when sudden pressure variations exceeding a predetermined value occur in said manifold, and

means for gradually equalizing the respective pressure variations in said chamber and said prises, in combination, a receiving machine, at least one generator for feeding gas under pressure intermittently to said receiving machine, a manifold connecting said generator with said receiving machine, a pressure regulating structure forming a chamber connected to said manifold, a conduit of relatively large section extending between said manifold and said chambena piston movable in said conduit, spring means for urging said piston toward an intermediate position in said conduit, abutment means for limiting the displacements of said piston in both directions, so as to stop transmission of pressure variations from said chamber to said manifold and inversely when sudden pressure variations exceeding a predetermined value occur in said manifold, and a conduit of relatively small section connecting said manifold with said chamber for gradually equalizing the respective pressure variations in said chamber and said manifold.

10. A system of the type described, which comprises, in combination, a receiving machine, at least one generator for feeding gas under pressure intermittently to said receiving machine, a manifold connecting said generator with said receiving machine, a pressure regulating structure forming a chamber connected to said manifold, a cylinder connected at one end with said manifold and at the other end with said chamber, a passage opening into said manifold and forming at least a part of said chamber, a piston movable in said passage, servo-motor means for controlling the position of said piston, and a piston slidable in the first mentioned cylinder for controlling said servo-motor means.

11. A system of the type described, which comprises, in combination, a receiving machine, at least one generator for feeding gas under pressure intermittently to said machine, a manifold connecting said generator with said receiving machine, a pressure regulating structure forming a chamber-connected to said manifold, a passage connecting said chamber with said manifold and forming at least one part of said chamber, a piston movable in said passage, servomotor means for controlling the position of said piston in said passage, means operative by the difference between the pressures in said chamber and said manifold, respectively, for operating said servo-motor means, and means for gradually equalizing the pressures in said manifold and said chamber, respectively. 12. A system of the type described, which comprises, in combination, a receiving machine, at least one generator for feeding fluid under pressure to said machine, a manifold connecting said generator with said receiving machine, means responsive to variations in the pressure in said manifold to regulate said generator, a pressure regulating structure forming a chamber connected to said manifold, and pressure responsive means for temporarily and at least partly bringing said regulating structure out of action in response to pressure variations in said manifold exceeding a predetermined value.

13. A system of the type described which comprises, in combination, a receiving machine, at

least one generator for feeding fluid under pressure to said machine, said generator having a. variable output, a conduit connecting said generator with said receiving machine, means forming a chamber constituting a pneumatic cushion communicating with said conduit and capable of damping variations of pressure in the conduit,'

and means responsive to sudden increase and decrease in a variable selected from the group consisting of the speedo! the receiving machine and the pressure in the conduit to render said chamber inoperative, said last means being inoperative when said variable is substantially constant, whereby variations of pressure in said conduit due to variations in said variable are increased.

14. A system of the type described which comprises, in combination, a receiving machine, at least one generator for feeding fluid under pressure to said machine, said generator having a variable output, a conduit connecting said generator with said receiving machine, means form ing a chamber constituting a pneumatic cushion communicating with said conduit and capable of damping variations of pressure in the conduit, means responsive to sudden increase and decrease in a variable selected from the group con creased, fuel supply means for said generator,-

and means responsive to variations in the pressure in said conduit to control said fuel supply means.

RAUL PATERAS PESCARA.