SOUND DAMPING ARRANGEMENT
United States Patent 3623572
A tubular element conveys fluid through a passage having an enlarged passage portion. Accommodated in the passage portion axially spaced from one another is a pair of plates each provided in the respective outer margin with a concentric annulus of apertures. An insert is accommodated between the plates and defines with the wall of the element an annular clearance. Its respective end faces face the plates and are each provided with recesses communicating with the clearance and with one of the apertures. A plurality of depressions are provided in the upstream one of the endfaces and register with respective apertures and a plurality of closing members are each received in one of the depressions closing the same except for a reduced cross-sectional area. Biasing means yieldably biases the respective closing member into closing position in which it resiliently closes partially the respectively associated aperture.
US Patent References:
Flow damping device
Marshall - April 1954 - 2674096
Temperature compensated device for absorbing transient pressure fluctuations
Stumm - June 1958 - 2838072
Desurger for liquid systems
Deily et al. - December 1958 - 2864403
Shock-absorber device for pneumatic suspension of vehicles
Boulet - January 1960 - 2919719
Piston accumulator
Mercier - January 1963 - 3074437
Flow damping device
Marshall - April 1954 - 2674096
Temperature compensated device for absorbing transient pressure fluctuations
Stumm - June 1958 - 2838072
Desurger for liquid systems
Deily et al. - December 1958 - 2864403
Shock-absorber device for pneumatic suspension of vehicles
Boulet - January 1960 - 2919719
Piston accumulator
Mercier - January 1963 - 3074437
Application Number:
05/090915
Publication Date:
11/30/1971
Filing Date:
11/19/1970
View Patent Images:
Export Citation:
Primary Class:
Other Classes:
138/31, 138/43
International Classes:
F16L55/04; F16L55/04; F01N1/20
Field of Search:
181/47,57,47.1,64.2,65,35,36.2,36,41,49,36.4 138/26,30,31,42,43
Primary Examiner:
Ward Jr., Robert S.
Claims:
I claim
1. A sound damping arrangement of the character described, comprising a fluid-conveying tubular element having a passage, including an enlarged passage portion through which fluid flows from an inlet to an outlet of said passage; an insert in said passage portion defining with the inner surface thereof an annular clearance intermediate said inlet and said outlet, said insert having an end face facing said inlet; a pair of apertured annular elements in said clearance at the upstream and downstream ends thereof, respectively; at least one depression in said end face and being juxtaposed with said inlet; at least one closing member juxtaposed with said inlet and closing said depression, said closing member having a surface facing the incoming fluid and provided with an aperture of reduced cross-sectional area communicating with the interior of said depression; and biasing means yieldably biasing said closing member to closing position tending to close said inlet.
2. A sound damping arrangement of the character described, comprising a fluid-conveying tubular element having a passage, including an enlarged passage portion, through which fluid flows in predetermined direction; a pair of plates in said passage portion axially spaced and provided with respective concentric annuli of marginally located apertures; an insert accommodated in said passage portion intermediate said plates and defining with the wall of said element an annular clearance, said insert having respective end faces adjacent said plates and provided with recesses each communicating with said clearance and with one of said apertures; a plurality of depressions in the upstream one of said end faces each registering with one of said apertures; a plurality of closing members each closing one of said depressions except for a reduced cross-sectional area; and biasing means yieldably biasing the respective closing members towards closing positions tending to close the respectively associated aperture.
3. A sound damping arrangement as defined in claim 2, wherein said plurality of depressions equal said plurality of apertures, and said plurality of closing members equal said plurality of depressions.
4. A sound damping arrangement as defined in claim 2, said passage having a predetermined cross-sectional area; and wherein each of the combined cross-sectional areas of said apertures of each of said annuli, of said recesses, of said depressions and of said annular clearance at least approximates said predetermined cross-sectional area.
5. A sound damping arrangement as defined in claim 2, said depressions being fluid bores open at said upstream end face; and wherein said closure members are plugs slidably accommodated in respective ones of said bores.
6. A sound damping arrangement as defined in claim 2, said closure members being resiliently deflectable diaphragms mounted in the respective depressions and deflectable into positions partially closing the respectively associated apertures.
7. A sound damping arrangement as defined in claim 6, said diaphragms consisting at least predominantly of yieldably deflectable material.
8. A sound damping arrangement as defined in claim 6; further comprising supporting means for yieldably supporting said diaphragms so that the same are yieldably deflectable.
9. A sound damping arrangement as defined in claim 2; and further comprising an annular member accommodated in said annular clearance and provided with an annulus of additional apertures concentric with the first-mentioned annuli.
10. A sound damping arrangement as defined in claim 9, said annular member having an outer margin, and said annulus of additional apertures being located in the region of said outer margin.
11. A sound damping arrangement as defined in claim 2; further comprising an annular groove connecting said recesses in the downstream one of said plates and having an open side facing towards said upstream plate.
1. A sound damping arrangement of the character described, comprising a fluid-conveying tubular element having a passage, including an enlarged passage portion through which fluid flows from an inlet to an outlet of said passage; an insert in said passage portion defining with the inner surface thereof an annular clearance intermediate said inlet and said outlet, said insert having an end face facing said inlet; a pair of apertured annular elements in said clearance at the upstream and downstream ends thereof, respectively; at least one depression in said end face and being juxtaposed with said inlet; at least one closing member juxtaposed with said inlet and closing said depression, said closing member having a surface facing the incoming fluid and provided with an aperture of reduced cross-sectional area communicating with the interior of said depression; and biasing means yieldably biasing said closing member to closing position tending to close said inlet.
2. A sound damping arrangement of the character described, comprising a fluid-conveying tubular element having a passage, including an enlarged passage portion, through which fluid flows in predetermined direction; a pair of plates in said passage portion axially spaced and provided with respective concentric annuli of marginally located apertures; an insert accommodated in said passage portion intermediate said plates and defining with the wall of said element an annular clearance, said insert having respective end faces adjacent said plates and provided with recesses each communicating with said clearance and with one of said apertures; a plurality of depressions in the upstream one of said end faces each registering with one of said apertures; a plurality of closing members each closing one of said depressions except for a reduced cross-sectional area; and biasing means yieldably biasing the respective closing members towards closing positions tending to close the respectively associated aperture.
3. A sound damping arrangement as defined in claim 2, wherein said plurality of depressions equal said plurality of apertures, and said plurality of closing members equal said plurality of depressions.
4. A sound damping arrangement as defined in claim 2, said passage having a predetermined cross-sectional area; and wherein each of the combined cross-sectional areas of said apertures of each of said annuli, of said recesses, of said depressions and of said annular clearance at least approximates said predetermined cross-sectional area.
5. A sound damping arrangement as defined in claim 2, said depressions being fluid bores open at said upstream end face; and wherein said closure members are plugs slidably accommodated in respective ones of said bores.
6. A sound damping arrangement as defined in claim 2, said closure members being resiliently deflectable diaphragms mounted in the respective depressions and deflectable into positions partially closing the respectively associated apertures.
7. A sound damping arrangement as defined in claim 6, said diaphragms consisting at least predominantly of yieldably deflectable material.
8. A sound damping arrangement as defined in claim 6; further comprising supporting means for yieldably supporting said diaphragms so that the same are yieldably deflectable.
9. A sound damping arrangement as defined in claim 2; and further comprising an annular member accommodated in said annular clearance and provided with an annulus of additional apertures concentric with the first-mentioned annuli.
10. A sound damping arrangement as defined in claim 9, said annular member having an outer margin, and said annulus of additional apertures being located in the region of said outer margin.
11. A sound damping arrangement as defined in claim 2; further comprising an annular groove connecting said recesses in the downstream one of said plates and having an open side facing towards said upstream plate.
Description:
BACKGROUND OF THE INVENTION
The present invention relates generally to damping arrangements, and more particularly to a sound damping arrangement. Still more particularly the present invention relates to an arrangement for damping sounds in a tubular element or conductor through which fluid in liquid or gaseous form flows.
In many instances sounds originate as fluid-- whether it be gaseous or liquid--flows through a tubular conductor. This is true, for instance, if liquid or gaseous fluid is passed through a tubular conductor at pressure and in relatively rapidly succeeding pulses, as is the case if such a tubular conductor receives the fluid from a compressor, from a motor or from a pump. When this takes place, the conductor is caused to vibrate and this frequently results in noises which may reach quite a high phone number.
Attempts have been made to suppress these undesired noises and by way of example it is pointed out that German Pat. No. 324,048 teaches to separate the stream of fluid flowing through such a tubular conductor, into several partial streams which are displaced with reference to one another in their direction of advancement. The arrangement provides for an enlarged portion in the passage of the tubular conductor which continues into several individual conductors which are different as to their length or their cross section. The purpose is to provide streams of gaseous or liquid fluid which are separated from one another and displaced with reference to one another. These are then conveyed into a single tube located downstream of the individual conductors and having a cross-sectional area corresponding to the cross-sectional area of the tubular conductor upstream of the individual conductors. However, it will be evident that such an arrangement is rather complicated, if only because of the plurality of individual conductors necessary and the couplings connecting them to the conductor carrying the incoming fluid and the conductor carrying the outgoing fluid. Also, of course, the assembly of such an arrangement is difficult and complicated and, moreover, it has been found that effectiveness of this arrangement is based more upon theoretical considerations than upon practical ones and in actual fact provides no more than marginal satisfactory results.
SUMMARY OF THE INVENTION
It is, accordingly, an object of the present invention to overcome the aforementioned disadvantages of the art.
More particularly it is an object of the present invention to provide an improved sound damping arrangement for application under the circumstances described before.
A concomitant object of the invention is to provide such a damping arrangement which is simple in its construction and highly reliable and effective in its operation.
In pursuance of the above objects, and others which will become apparent hereafter, one feature of the invention resides in a sound damping arrangement comprising a fluid-conveying tubular element having a passage, including an enlarged passage portion, through which fluid flows in predetermined direction. A pair of plates is provided in this passage portion axially spaced and provided with respective concentric annuli of marginally located apertures, meaning that the apertures are located in a margin of the plates. An insert is accommodated in the passage portion intermediate the plates and defines with the wall of the element an annular clearance. The insert has respective end faces each adjacent one of the plates and each provided with recesses which respectively communicate with the clearance and with one of the apertures. A plurality of depressions is provided in the upstream one of these end faces and each registers with one of the apertures. A plurality of closing members is also provided, each received in one of the depressions closing the same except for a reduced cross-sectional area. Biasing means yieldably biases the respective closing members to closing positions in which they partially close the respectively associated aperture.
It is advantageous but not necessary that each of the apertures is associated with one of the depressions and with one of the closing members.
An arrangement constructed according to my invention as just briefly outlined has the advantage that, firstly, it is very simple in its construction and assembly. Furthermore, it in effect operates as a vibration integrator, which is to say that it has been found that the amplitudes of the vibrations resulting from pulsing of the fluid passing through the passage are reduced within the system and that their phases are displaced through nearly 180° . This strongly reduces the vibrations which occur in the system and therefore the noises resulting from the vibrations.
It will be appreciated that phase shifting is caused essentially through the resiliently biased closing members, because the pulsed streams of fluid which are unthrottled and into which the initial undivided stream of fluid is subdivided, contact these closing members whose countervibration is stabilized by the fact that the openings of reduced cross-sectional area which are provided in the closure members delay the elastic yielding to-and-fro of the closure members and thus afford the stabilization.
The construction according to the present invention also is saving of space in that it is entirely accommodated within the enlarged passage portion in which the fluid medium is subdivided without any throttling effect into the comparatively small number of individual streams, repeatedly deflected in its direction of flow and reunited into a single stream. The effect obtainable with the construction according to the present invention is most advantageous if, in accordance with a further concept of the invention, the combined cross-sectional areas in the arrangement according to the present invention correspond at least substantially to the cross section area of the passage itself -- that is the passage upstream or downstream of the enlarged passage portion. The annular clearance may itself accommodate an additional annular element provided with a further annulus of apertures which are concentric with the annulii of apertures in the first-mentioned plates.
The closure members may be configurated as plugs of small mass which are slidably accommodated in the respective depressions and urged by biasing springs into closing engagement with the respective apertures. However, it is also possible to configurate the closing members as inherently resiliently deflectable membranes, or as membranes which are resiliently deflectably supported; these latter two possibilities may be of particular advantage if the medium is under comparatively small or low pressure.
The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a somewhat diagrammatic longitudinal section through an embodiment according to the present invention;
FIG. 2 is a fragmentary detailed view showing a further embodiment of the invention; and
FIG. 3 is a view similar to FIG. 1 but illustrating still another embodiment of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Discussing now the drawing in detail, and firstly the embodiment illustrated in FIG. 1, it will be seen that reference numeral 1 identifies a portion of a tubular fluid-conveying element which comprises an additional portion 2 located at one end of the portion 1 and an additional portion 4 located at the opposite at the portion 1. The portions 2 and 4 have respective passage portions 3 and 5 for fluid flow in the direction of the arrow A, and the portion 1 has an enlarged passage portion 1a which communicates with the passage portions 3 and 5.
As FIG. 1 shows, there are accommodated in the passage portion 1a two plates 6 and 9 located at its opposite axial ends. The plate 6 is provided in its marginal portion with a circumferentially extending annulus of apertures 8, and a similar annulus of apertures 10 is provided in the plate 9. The annuli 8 and 10 are concentric with one another and with the axis of the passage portion 1a. The number of apertures in the annuli 8 and 10 is preferably but not necessarily an uneven number, and the combined cross-sectional area of the apertures of the annulus 8 preferably corresponds at least substantially to the cross-sectional area of the passage portion 3. The same is true with respect to the passage portion 5 of the combined cross-sectional area of the apertures of the annulus 10. The plates 6 and 9 may be of one piece with the tubular portions 2 and 4, respectively, and in the illustrated embodiment this is shown only for the plate 9 and the tubular portion 4. Such an arrangement is advantageous from a point of view of simplifying the production of the novel construction.
A space 11 downstream of the plate 9 in effect constitutes a collecting chamber in which the plurality of individual fluid streams are reunited before passing into the passage portion 5.
As FIG. 1 shows a solid insert 12 is accommodated intermediate the plates 6 and 9 and has an outer diameter smaller than the inner diameter of the passage portion 1a so that it defines with the wall of the portion 1 an annular channel 13 whose cross-sectional area according to a preferred embodiment of the invention corresponds at least substantially to the cross-sectional area of the passage portion 3.
The opposite axial end faces of the insert 12 face the plates 6 and 9, respectively. That end face which faces the plate 6, that is which faces in upstream direction as seen with respect to the fluid flow in the direction of the arrow A, is provided with a stepped recess 14 so that only a portion 12a actually contacts the plate 6, whereby the apertures of the annulus 8 are free, that is they are not covered. Axial bores 16 are provided as illustrated which respectively register with apertures of the annulus 8 and in each of which a portion 17a of a plug 17 serving as a closure member is accommodated. The portion 17a is hollow as shown and accommodates an extension spring 18 which continuously displaces the closure member 17 to the broken line position shown. In the illustrated embodiment the members 17 are each provided with a bore 19 serving as a throttling bore and communicating with the hollow interior in which the spring 18 is located. The members 17 are guided in the respective recesses 16 in as friction-free a manner as possible so that they are slidable therein.
The essential point of the construction shown in FIG. 1 is that the space in the interior of the recesses 16 and not filled by the portion 17a of the member 17, is in communication with the spaces of the construction through which the liquid or gaseous medium flows through an aperture or opening 19 of reduced cross section, it being evident that the throttling bore 19 can also be replaced by grooves, channels or the like if desired.
The apertures of the annulus 10 in the plate 9 are in communication with the space 13 by radial bores or recesses 20 and an annular groove 15 communicates the bores 20 with one another and with the apertures 10. I have illustrated that it is also possible to provide an annular member 21 located in the clearance 13 and provided with an additional annulus of apertures 22 whose combined cross-sectional area again at least substantially corresponds to the cross-sectional area of the passage portion 3.
It will be appreciated that the broken line position of the member 17 shown in FIG. 1 will be the normal position when no fluid flows. When fluid flows in the direction of the arrow A, however, the members 17 are displaced to their full-line position without exerting any throttling effect on the flowing fluid. Due to the fact that the space upstream of the members 17 through which the medium flows with variable pressure, is in communication with the interior of the recesses 16 which is not filled by the portion 17a of the respective member 17, via the throttling bore 19, an approximate pressure equalization is obtained between these two spaces so that the member 17 reciprocates to-and-fro in a phase-shifted relationship. This results in a strong reduction in the amplitudes of the exciter vibrations. Adding to this the fact that the medium is caused to change its direction of flow by the presence of the various plates, the liquid or gaseous medium passes through the passage portion 5 almost without pulsing and therefore almost without causing any further noise due to the production of vibrations.
A further embodiment is illustrated in FIG. 2. It differs from the embodiment of FIG. 1 only in the illustrated details so that the remainder of the illustration of FIG. 1 has been omitted as not essential for an understanding of the embodiment in FIG. 2. As will be seen, in FIG. 2 the members 17 have been replaced with closure members in form of diaphragms or membranes 22 configurated as a foldable diaphragm and a plate 23 connected with the diaphragm and provided with a throttling bore or aperture 19 which communicates with the interior of the respective recess 16. The spring 18 again serves the same purpose as described with respect to the embodiment of FIG. 1, urging the plate portion 23 into closing relationship against the apertures 8.
However, it will be appreciated that further modifications are also possible within the scope and intent of the present invention. It is for instance possible to produce the insert 12 not as a separate element, but as one piece with either the annular member 31, the portion 4, or with both. Such production can be by casting or the like. Particularly if the medium which flows through this construction is under high pressure and if circumstances generally are disadvantageous, it is possible to provide two or more of the arrangements in a single tubular conductor in sequence. These arrangements need not be identical and could for instance be alternatingly or in other sequence of the embodiments of FIGS. 1 and 2. Naturally, the construction according to the present invention need not be located downstream of the source of fluid, for instance a compressor, but could be built right into the source of fluid, that is be located within the physical confines of the same rather than in an exteriorly located tubular conduit.
It has also been found that the arrangement according to the present invention will operate satisfactorily even if the flow of fluid is in direction opposite to that which has been illustrated in FIG. 1. It is then only necessary to assure that the medium can act upon the respective closure members, for which purpose an arrangement such as that which has been suggested for purposes of information in FIG. 1 can be provided. Such an arrangement is in form of an annular groove 24 provided in the plate 6 for the purpose of assuring that the medium can move to the respective members 17 from the lateral regions thereof, rather than through the respective apertures 8 as is the case when the flow is in normal direction, that is the direction indicated by the arrow A.
Coming, finally, to the embodiment of FIG. 3 it will be seen that this is somewhat analogous to, but simpler than that of FIG. 1. The embodiment of FIG. 3 may be used with particular advantage in applications where only relatively small fluid-flow quantities are involved.
Like reference numerals identify like elements as those in FIG. 1. Here, however, the plates of FIG. 1 have been omitted. Instead, the element 12 is provided with a single depression 16 in which the element 17 is slidably guided, in the same manner as disclosed in FIG. 1. The biasing spring 18 is again provided and the end face of the member 17 which is juxtaposed is again provided with an aperture 19 of reduced cross section which communicates with the interior of the depression 16.
Two apertured annular members 30 and 32 are provided in the clearance 13 in the region of the opposite axial ends thereof; they may be fast with the element 12 or otherwise constitute therewith a unit to facilitate assembly and disassembly. The members 30 and 32 have apertures 31 and 33 which respectively communicate with the clearance 13 and the inlet 3 or the outlet 5 (via chamber 11), as the case may be. Although each member may have several apertures, particularly the member 32 may be provided with a single aperture 33 if desired and if circumstances permit. Element 12 with members 30 and 32 is maintained in position by a mounting insert 25 which in the illustrated embodiment has a pass-through opening coaxial with the inlet 3.
The operational principle of the FIG. 3 embodiment is the same as in FIGS. 1 and 2, i.e., the element or piston 17 compensates and "smoothes out" pressure variations in the fluid flow.
It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of constructions differing from the types described above.
While the invention has been illustrated and described as embodied in a sound damping arrangement, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.
Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.
What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims.
The present invention relates generally to damping arrangements, and more particularly to a sound damping arrangement. Still more particularly the present invention relates to an arrangement for damping sounds in a tubular element or conductor through which fluid in liquid or gaseous form flows.
In many instances sounds originate as fluid-- whether it be gaseous or liquid--flows through a tubular conductor. This is true, for instance, if liquid or gaseous fluid is passed through a tubular conductor at pressure and in relatively rapidly succeeding pulses, as is the case if such a tubular conductor receives the fluid from a compressor, from a motor or from a pump. When this takes place, the conductor is caused to vibrate and this frequently results in noises which may reach quite a high phone number.
Attempts have been made to suppress these undesired noises and by way of example it is pointed out that German Pat. No. 324,048 teaches to separate the stream of fluid flowing through such a tubular conductor, into several partial streams which are displaced with reference to one another in their direction of advancement. The arrangement provides for an enlarged portion in the passage of the tubular conductor which continues into several individual conductors which are different as to their length or their cross section. The purpose is to provide streams of gaseous or liquid fluid which are separated from one another and displaced with reference to one another. These are then conveyed into a single tube located downstream of the individual conductors and having a cross-sectional area corresponding to the cross-sectional area of the tubular conductor upstream of the individual conductors. However, it will be evident that such an arrangement is rather complicated, if only because of the plurality of individual conductors necessary and the couplings connecting them to the conductor carrying the incoming fluid and the conductor carrying the outgoing fluid. Also, of course, the assembly of such an arrangement is difficult and complicated and, moreover, it has been found that effectiveness of this arrangement is based more upon theoretical considerations than upon practical ones and in actual fact provides no more than marginal satisfactory results.
SUMMARY OF THE INVENTION
It is, accordingly, an object of the present invention to overcome the aforementioned disadvantages of the art.
More particularly it is an object of the present invention to provide an improved sound damping arrangement for application under the circumstances described before.
A concomitant object of the invention is to provide such a damping arrangement which is simple in its construction and highly reliable and effective in its operation.
In pursuance of the above objects, and others which will become apparent hereafter, one feature of the invention resides in a sound damping arrangement comprising a fluid-conveying tubular element having a passage, including an enlarged passage portion, through which fluid flows in predetermined direction. A pair of plates is provided in this passage portion axially spaced and provided with respective concentric annuli of marginally located apertures, meaning that the apertures are located in a margin of the plates. An insert is accommodated in the passage portion intermediate the plates and defines with the wall of the element an annular clearance. The insert has respective end faces each adjacent one of the plates and each provided with recesses which respectively communicate with the clearance and with one of the apertures. A plurality of depressions is provided in the upstream one of these end faces and each registers with one of the apertures. A plurality of closing members is also provided, each received in one of the depressions closing the same except for a reduced cross-sectional area. Biasing means yieldably biases the respective closing members to closing positions in which they partially close the respectively associated aperture.
It is advantageous but not necessary that each of the apertures is associated with one of the depressions and with one of the closing members.
An arrangement constructed according to my invention as just briefly outlined has the advantage that, firstly, it is very simple in its construction and assembly. Furthermore, it in effect operates as a vibration integrator, which is to say that it has been found that the amplitudes of the vibrations resulting from pulsing of the fluid passing through the passage are reduced within the system and that their phases are displaced through nearly 180° . This strongly reduces the vibrations which occur in the system and therefore the noises resulting from the vibrations.
It will be appreciated that phase shifting is caused essentially through the resiliently biased closing members, because the pulsed streams of fluid which are unthrottled and into which the initial undivided stream of fluid is subdivided, contact these closing members whose countervibration is stabilized by the fact that the openings of reduced cross-sectional area which are provided in the closure members delay the elastic yielding to-and-fro of the closure members and thus afford the stabilization.
The construction according to the present invention also is saving of space in that it is entirely accommodated within the enlarged passage portion in which the fluid medium is subdivided without any throttling effect into the comparatively small number of individual streams, repeatedly deflected in its direction of flow and reunited into a single stream. The effect obtainable with the construction according to the present invention is most advantageous if, in accordance with a further concept of the invention, the combined cross-sectional areas in the arrangement according to the present invention correspond at least substantially to the cross section area of the passage itself -- that is the passage upstream or downstream of the enlarged passage portion. The annular clearance may itself accommodate an additional annular element provided with a further annulus of apertures which are concentric with the annulii of apertures in the first-mentioned plates.
The closure members may be configurated as plugs of small mass which are slidably accommodated in the respective depressions and urged by biasing springs into closing engagement with the respective apertures. However, it is also possible to configurate the closing members as inherently resiliently deflectable membranes, or as membranes which are resiliently deflectably supported; these latter two possibilities may be of particular advantage if the medium is under comparatively small or low pressure.
The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a somewhat diagrammatic longitudinal section through an embodiment according to the present invention;
FIG. 2 is a fragmentary detailed view showing a further embodiment of the invention; and
FIG. 3 is a view similar to FIG. 1 but illustrating still another embodiment of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Discussing now the drawing in detail, and firstly the embodiment illustrated in FIG. 1, it will be seen that reference numeral 1 identifies a portion of a tubular fluid-conveying element which comprises an additional portion 2 located at one end of the portion 1 and an additional portion 4 located at the opposite at the portion 1. The portions 2 and 4 have respective passage portions 3 and 5 for fluid flow in the direction of the arrow A, and the portion 1 has an enlarged passage portion 1a which communicates with the passage portions 3 and 5.
As FIG. 1 shows, there are accommodated in the passage portion 1a two plates 6 and 9 located at its opposite axial ends. The plate 6 is provided in its marginal portion with a circumferentially extending annulus of apertures 8, and a similar annulus of apertures 10 is provided in the plate 9. The annuli 8 and 10 are concentric with one another and with the axis of the passage portion 1a. The number of apertures in the annuli 8 and 10 is preferably but not necessarily an uneven number, and the combined cross-sectional area of the apertures of the annulus 8 preferably corresponds at least substantially to the cross-sectional area of the passage portion 3. The same is true with respect to the passage portion 5 of the combined cross-sectional area of the apertures of the annulus 10. The plates 6 and 9 may be of one piece with the tubular portions 2 and 4, respectively, and in the illustrated embodiment this is shown only for the plate 9 and the tubular portion 4. Such an arrangement is advantageous from a point of view of simplifying the production of the novel construction.
A space 11 downstream of the plate 9 in effect constitutes a collecting chamber in which the plurality of individual fluid streams are reunited before passing into the passage portion 5.
As FIG. 1 shows a solid insert 12 is accommodated intermediate the plates 6 and 9 and has an outer diameter smaller than the inner diameter of the passage portion 1a so that it defines with the wall of the portion 1 an annular channel 13 whose cross-sectional area according to a preferred embodiment of the invention corresponds at least substantially to the cross-sectional area of the passage portion 3.
The opposite axial end faces of the insert 12 face the plates 6 and 9, respectively. That end face which faces the plate 6, that is which faces in upstream direction as seen with respect to the fluid flow in the direction of the arrow A, is provided with a stepped recess 14 so that only a portion 12a actually contacts the plate 6, whereby the apertures of the annulus 8 are free, that is they are not covered. Axial bores 16 are provided as illustrated which respectively register with apertures of the annulus 8 and in each of which a portion 17a of a plug 17 serving as a closure member is accommodated. The portion 17a is hollow as shown and accommodates an extension spring 18 which continuously displaces the closure member 17 to the broken line position shown. In the illustrated embodiment the members 17 are each provided with a bore 19 serving as a throttling bore and communicating with the hollow interior in which the spring 18 is located. The members 17 are guided in the respective recesses 16 in as friction-free a manner as possible so that they are slidable therein.
The essential point of the construction shown in FIG. 1 is that the space in the interior of the recesses 16 and not filled by the portion 17a of the member 17, is in communication with the spaces of the construction through which the liquid or gaseous medium flows through an aperture or opening 19 of reduced cross section, it being evident that the throttling bore 19 can also be replaced by grooves, channels or the like if desired.
The apertures of the annulus 10 in the plate 9 are in communication with the space 13 by radial bores or recesses 20 and an annular groove 15 communicates the bores 20 with one another and with the apertures 10. I have illustrated that it is also possible to provide an annular member 21 located in the clearance 13 and provided with an additional annulus of apertures 22 whose combined cross-sectional area again at least substantially corresponds to the cross-sectional area of the passage portion 3.
It will be appreciated that the broken line position of the member 17 shown in FIG. 1 will be the normal position when no fluid flows. When fluid flows in the direction of the arrow A, however, the members 17 are displaced to their full-line position without exerting any throttling effect on the flowing fluid. Due to the fact that the space upstream of the members 17 through which the medium flows with variable pressure, is in communication with the interior of the recesses 16 which is not filled by the portion 17a of the respective member 17, via the throttling bore 19, an approximate pressure equalization is obtained between these two spaces so that the member 17 reciprocates to-and-fro in a phase-shifted relationship. This results in a strong reduction in the amplitudes of the exciter vibrations. Adding to this the fact that the medium is caused to change its direction of flow by the presence of the various plates, the liquid or gaseous medium passes through the passage portion 5 almost without pulsing and therefore almost without causing any further noise due to the production of vibrations.
A further embodiment is illustrated in FIG. 2. It differs from the embodiment of FIG. 1 only in the illustrated details so that the remainder of the illustration of FIG. 1 has been omitted as not essential for an understanding of the embodiment in FIG. 2. As will be seen, in FIG. 2 the members 17 have been replaced with closure members in form of diaphragms or membranes 22 configurated as a foldable diaphragm and a plate 23 connected with the diaphragm and provided with a throttling bore or aperture 19 which communicates with the interior of the respective recess 16. The spring 18 again serves the same purpose as described with respect to the embodiment of FIG. 1, urging the plate portion 23 into closing relationship against the apertures 8.
However, it will be appreciated that further modifications are also possible within the scope and intent of the present invention. It is for instance possible to produce the insert 12 not as a separate element, but as one piece with either the annular member 31, the portion 4, or with both. Such production can be by casting or the like. Particularly if the medium which flows through this construction is under high pressure and if circumstances generally are disadvantageous, it is possible to provide two or more of the arrangements in a single tubular conductor in sequence. These arrangements need not be identical and could for instance be alternatingly or in other sequence of the embodiments of FIGS. 1 and 2. Naturally, the construction according to the present invention need not be located downstream of the source of fluid, for instance a compressor, but could be built right into the source of fluid, that is be located within the physical confines of the same rather than in an exteriorly located tubular conduit.
It has also been found that the arrangement according to the present invention will operate satisfactorily even if the flow of fluid is in direction opposite to that which has been illustrated in FIG. 1. It is then only necessary to assure that the medium can act upon the respective closure members, for which purpose an arrangement such as that which has been suggested for purposes of information in FIG. 1 can be provided. Such an arrangement is in form of an annular groove 24 provided in the plate 6 for the purpose of assuring that the medium can move to the respective members 17 from the lateral regions thereof, rather than through the respective apertures 8 as is the case when the flow is in normal direction, that is the direction indicated by the arrow A.
Coming, finally, to the embodiment of FIG. 3 it will be seen that this is somewhat analogous to, but simpler than that of FIG. 1. The embodiment of FIG. 3 may be used with particular advantage in applications where only relatively small fluid-flow quantities are involved.
Like reference numerals identify like elements as those in FIG. 1. Here, however, the plates of FIG. 1 have been omitted. Instead, the element 12 is provided with a single depression 16 in which the element 17 is slidably guided, in the same manner as disclosed in FIG. 1. The biasing spring 18 is again provided and the end face of the member 17 which is juxtaposed is again provided with an aperture 19 of reduced cross section which communicates with the interior of the depression 16.
Two apertured annular members 30 and 32 are provided in the clearance 13 in the region of the opposite axial ends thereof; they may be fast with the element 12 or otherwise constitute therewith a unit to facilitate assembly and disassembly. The members 30 and 32 have apertures 31 and 33 which respectively communicate with the clearance 13 and the inlet 3 or the outlet 5 (via chamber 11), as the case may be. Although each member may have several apertures, particularly the member 32 may be provided with a single aperture 33 if desired and if circumstances permit. Element 12 with members 30 and 32 is maintained in position by a mounting insert 25 which in the illustrated embodiment has a pass-through opening coaxial with the inlet 3.
The operational principle of the FIG. 3 embodiment is the same as in FIGS. 1 and 2, i.e., the element or piston 17 compensates and "smoothes out" pressure variations in the fluid flow.
It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of constructions differing from the types described above.
While the invention has been illustrated and described as embodied in a sound damping arrangement, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.
Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.
What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims.