DE1169105B - Sound absorbing wall filled with liquid - Google Patents

Description

Sound-insulating, liquid-filled wall The invention relates to a hollow wall which is filled with liquid for the purpose of soundproofing.

It is known that sound propagation from noise sources is disruptive to reduce or prevent and thus also by sound-absorbing arrangements to avoid paying attention to the location of sound emitting devices or devices, e.g. B. test stands of engines of all kinds or other noisy Aggregates, is steered.

For this purpose it is known that the noise source is through a hood to be covered with sound-absorbing walls or in some other way with sound-absorbing To surround walls. The walls of such devices were previously made of solid Components, for example in the form of plates made of steel or solid or hardening building materials, whereby their insulating effect is the higher or better is, the heavier the walls are made.

Liquid-filled walls are not in themselves new. For example water tanks for radiation shielding of nuclear reactors are known, the walls of which are stationary and rigid and are made of steel or the like.

It has also become known to achieve a uniform internal temperature Walls or roofs made of watertight glass containers to be used with a heat radiation absorbent liquid are filled. The aspect of sound insulation plays a role here not matter. The suggestion for sound insulation has also become known to use a suitable liquid to fill the pores of sound absorbing material, which is arranged in the cavity of a sound-absorbing plate.

All known soundproofing structures have in common that the for the sound insulation decisive mass per unit area is an integral part of the Construction forms.

Requires sound insulation, which is particularly necessary at high sound levels therefore a very large amount of building materials, manpower and time, in particular for soundproofing devices that are only needed temporarily and are therefore transportable must be, is not justifiable.

These disadvantages are eliminated by the invention.

It therefore assumes a hollow wall filled with liquid because a liquid can be easily filled and drained anywhere and as a cavity filling the main part of sound-absorbing the mass forms. this makes possible a significant reduction in the transport weight, since the one that determines the sound insulation Mass to be fed to the sound insulation system at the respective installation site needs.

According to the invention, the wall shells consist entirely or in part made of flexible foldable material, e.g. B. plastic or rubber. This achieves that they take up a greatly reduced volume when transported without filling. At the point of use is only then filled with the liquid.

As a rule, the wall is given by the hydrostatic pressure the filling to its full volume.

The invention also includes a hollow wall, the two wall shells of which are formed by inflated envelopes made of flexible, foldable material. In this In this case, the sound-absorbing liquid is located between the shells. Such Air-inflated envelopes are known as building walls per se.

The invention has the significant advantage that also for education Highly sound-insulating walls now only require thin shell-like shells which, with suitable support, are not inherently rigid or solid building materials require, but z. B. from a liquid-tight plastic or rubber with or can be formed without fabric or fabric insert or overlay and only need to be dimensioned so that they absorb the pressure of the liquid introduced can.

For example, when using water as a sound-absorbing liquid these placed in place in the sheath, e.g. B. can be pumped in, can be formed by the invention in a simple manner transportable sound insulation systems be used for in many cases where only temporary sound insulation is required, be it z. B. for measuring purposes (defined measuring space for e.g. turbines etc.) or for testing engines or other noisy aggregates of all Kind, there is an urgent need.

If you wanted to z. B. portable sound-emitting motors subject to a test of good sound insulation at their respective and any location to be able to move systems for sound insulation according to the usual construction principles produce, so would because of the large size and weight of the walls or components have significant difficulties during transport, assembly, etc., which are completely avoided when using the invention.

This fact is essential as with the permanent further development towards more powerful and also more space-consuming units with correspondingly large radiated sound energies the dimensions of the sound-absorbing Plants keep getting bigger.

With an appropriate design of the shell, it can be introduced of water or possibly another liquid until it is complete Tightening are inflated and thus get their intended shape. Through this is made possible that the sound-absorbing mass at any point, especially from below, which is supplied to the prepared shell laid down at the relevant location, as a result of which the construction of a sound-absorbing system can be accomplished in a simple manner can. The shell is through the liquid or. Water pressure a certain static strength conferred. The structure of the sound-absorbing wall designed therefore much easier than using a non-liquid sound-absorbing one Mass, such as B. sand, filled from above into the previously erected shell would have to be.

For acoustic insulation of machine parts emitting strong noise, z. B. of turbo generator sets, are known to be sound-absorbing hoods made of metal, which are covered on the inside with mineral material. All such Encapsulations have because of their unintentionally heat-insulating structure in their Inside often show a temperature increase, which is only due to an additional Fan-operated ventilation to the limit of just about continuous operation bearable temperatures can be suppressed.

Each ventilation opening must also be provided with a silencer whose acoustic effect corresponds to the insulation of the hood parts.

The invention now makes it possible without additional components like silencers and fans, because of the liquid-cooled Walls heat is absorbed or removed with cooled liquid circulation. For repair and overhaul work, replacement of machine parts, etc. makes the tedious dismantling and reassembly, especially of the many sheet steel plates very annoying noticeable with the previous hood constructions. Because of the invention it is now possible to make the dismantling and assembly less cumbersome and thus less inconvenient To be able to carry out emergency work with the necessary speed. the Liquid only needs to be drained and the so emptied through the hollow wall formed double jacket to be unrolled on the scaffolding.

The same applies vice versa for the structure. Through the Invention generally results in an easily removable noise protection for everyone possible sources of noise such as B. Compressors, screw compressors, pneumatic hammers, Transformers, engines of all kinds, etc. Depending on the particular case at hand the most varied demands are made on the sound insulation effect.

It is therefore an advantage that, in principle, the simplest way through the invention Way, namely by a corresponding distance between the wall shells receiving the liquid, a sound insulation up to very high values can be achieved. Suitable materials the way rubber and plastics represent them, like liquids, have none to speak of Flexural rigidity. This means that practically no track adjustment effect can occur, as it is shifted to very high frequencies, creating the risk of break-ins the insulating effect in the hearing area disappears. This represents another benefit of the Invention compared to sound-absorbing devices made of rigid homogeneous or heterogeneous Elements. Finally, the shell serving to hold the liquid can made from a single closed piece or at least from only a few pieces thereby avoiding the dreaded slot formations that are too high Can lead to a loss of sound-absorbing effect. On top of that, in contrast to sound-insulating hoods or other coverings made of solid building materials or Components in a device according to the invention no additional radiation occurs as a result of excitation of the natural frequencies of the walls. The arrangement of the Radiation damping agents are therefore unnecessary, especially when using one of the Liquid-absorbing plastic or rubber cover these materials themselves have great internal damping.

A casing designed according to the invention in the form of a hollow one Wall which, as already mentioned, is itself a has a certain static strength, can be in the amount required for operation Location can be easily held or supported by means of a simple tubular frame. The one caused by this as well as by a pumping system that may have to be carried along However, more transport is compared to the transport weight and the transport space for sound-absorbing envelopes made of solid building materials or components, e.g. B. conventional Steel plates. also irrelevant for multi-layer training, especially since for the creation these known facilities auxiliary structures or auxiliary scaffolding and lifting devices are indispensable. Taking into account the fact that when using water as a sound-absorbing liquid, these are used in most of the installation locations of the walls is available, are thus compared to the previously known sound-absorbing Facilities for the transport and handling of dead weight largely avoided, What is particularly important for transportable devices.

A wall according to the invention is also used when using in itself combustible material for absorbing the liquid, e.g. B. of water, fireproof. If necessary, the fire resistance can be increased by increasing the cooling effect the liquid is increased by appropriate circulation of the liquid. on In this way, the liquid can also be used as a coolant, whereby the advantage is achieved that in many cases because of the risk of excessive heat build-up applied air cooling with the necessary inlet and outlet openings formed sound bridges are avoided, as already shown in an example has been.

Furthermore, an asbestos covering can also be used to increase the fire resistance be provided on the wall. Even then, the advantages mentioned are largely present when the hollow walls that absorb the sound-absorbing liquid or the walls of which are partly made of rigid building materials or components. These Fabrics or items are then made with flexible foldable material such as plastic or rubber, applied in combination.

Another area of application of the invention is sound-absorbing when executed Given window, e.g. B. with observation windows for very noisy engine test stands, for test stands of jet engines or for studio systems and the like consist of transparent material at the relevant point and are also included clear liquid filled. This will take the place of those previously used thick-walled and up to three-fold arranged glass, z. B. Safety glass panes only two thin-walled discs made of transparent plastic, the space between them completely with a transparent insulating liquid, e.g. B. clear water, filled is.

The following are the most important advantages that can be achieved with the invention Compiled: 1. Temporary sources of noise can be acoustically quickly and cheaply be dammed.

2. Fixed large noise sources such as B. turbo generators, compressors etc. are acoustically isolated by a damping means, which in a short time with a few Handles can be removed from the location of the noise source (for repairs, replacements of machine parts, etc.).

Further features of the invention emerge from the drawings embodiments shown as examples. It shows F i g. 1 shows a cross section through a hood-like wall covering an engine test stand, FIG. 2 a schematic cross-sectional representation of a sound-absorbing wall made of individual elements, F i g. 3 shows a corresponding illustration of another embodiment, FIG. 4th a cross section through a device similar to that according to FIGS. 1, 5 a perspective view of part of a wall in the form of a hollow cylindrical Fig. 6 shows the cross section through a system of two soundproof walls, F. i g. 7 shows the cross section through a mobile soundproofing device, FIG. 8 a Cross section through a double wall.

According to Fig. 1, a sound-absorbing room wall is hood-like or bell-like Form by several envelope-shaped, ring-like elements 1 made of flexibly foldable material educated. The elements 1 are coated with a soundproofing liquid, z. B. water, filled to the brim, each through a special feed line 2 by means of a pump 4 is pumped in. The individual ring-like elements are with air ducts 3 provided, which are closed by valves and by which when pumping in the Water can escape the air.

The ring-like elements are placed on a light frame 5, which can be formed in a manner known per se from steel pipes. To the upper end the insulating hood can have a splitter silencer 6 in the opening of the uppermost ring-like Elements 1 be used. For the sound-damped exit of the gases to be tested Motor or other unit 7 can be arranged damper 8. These dampers can, as has already been proposed for jet engines, as self-propelled guns be trained.

In the event of a greater overpressure occurring inside the test room can the gases between the layers of the individual ring-like elements to the outside to escape, whereby the construction ensures a certain explosion protection.

For acoustic sealing of the bed joints and for mutual engagement F i g shows against lateral slipping. 2 shell-shaped elements 1 with a wedge-shaped profiling and F i g. 3 elements with an undercut bead profile 9, 10.

In the case of the in FIG. 4 device shown, which in its design after the hood. F i g. 1, there is the sound-absorbing hollow wall from only two parts, 12, which, when inflated, correspond to the shape of the hood Form spherical sections. The parts 11, 12 are each hollow from the closed Walls 13 are formed, the side and end walls of which contain the sound-absorbing liquid take up between them. The walls 13 can in turn be made of plastic, Rubber or the like exist and reinforced with a fabric system of such training be that they fill the plump with water or some other liquid the Assume the desired shape, but in the unfilled state, without a specific shape to form, are loosely collapsible.

In Fig. 4 are the walls 13 forming the hood parts 11, 12 with dashed lines 11 ', 12' shown in a position in which they are before Righting to be spread on the ground. By the pumps 4 'and 4 "is the Such a pressure is imparted to water or some other liquid that thereby a counterpressure is created in the sleeves reinforced with a fabric system and the shells acquire a certain inherent rigidity.

With 14 and 15 in Fig. 4 valves are designated by which when Pumping in the liquid allows the air to escape from the envelopes 13. The valves can be operated electrically or electromagnetically. If necessary, can also Here a light pipe frame od. Like. Are arranged that the hood part, l2 in an upright state supports. For the sake of clarity is such a framework in FIG. 4 not shown.

The side walls of the sheaths 13 can be secured by flexible cables 16 Made of nylon, steel or the like. Be connected to each other, which serve to the hydrostatic exerted on both opposite side walls of the casings To compensate for the pressure of the pumped-in liquid.

If necessary, the hood parts 11, 12 can be connected by means of anchors 17 be anchored in the ground.

Otherwise, in the embodiment of FIG. 4, the training such that the two hood parts 11, 12 suddenly occur in the interior of the hood The excess pressure in the apex differs, which in turn provides a certain degree of explosion protection is guaranteed.

FIGS. 5 and 6 show that the wall surface facing the noise source is designed wholly or partially sound-absorbing, through the arrangement wedge-shaped sound absorber 19 made of open-pore plastic with fine channels or consist of sound-absorbing minerals. The shells of the wall 18 are here also connected to one another by nylon ropes or other ropes 16.

While the wall according to FIG. 5 forms a hollow cylinder, FIG. 6 shows the application of the invention in a soundproofing system that consists of the hollow walls 20 and 21 filled with liquid. These serve the acoustic shadowing.

The sound shadow of the noise source 7 is shown in FIG. 6 in each case for the walls 20, 21 by the dashed lines 22 for the high and by the lines 23 for the low frequencies indicated schematically and shows that up to one a considerable noise protection depending on the height of the two walls 20, 21 distance can be reached.

Of course, such a system can also be made with rectangular, Polygonal or circular outline are formed.

F i g. 7 shows a mobile aircraft engine test bench of tubular Shape. Here, the outer wall shell is made of flexible foldable material in places Material 34 and the inner wall shell made of rigid material 32, e.g. B. light metal, manufactured.

After introducing and assembling the test object 35, z. B. a jet engine, at the test site on the test stand or thrust measuring vehicle 36 inside the mobile test stand is by pumping in sound-absorbing liquid, such as. B. water over the Connection piece 37 the space between the fixed inner shell 32 and the expandable Outer shell 33, 34 filled to the brim, the outer shell 33, 34 being the dashed Takes shape.

This mobile test stand can also be used at any point the wall sound-absorbing observation windows are created.

During the test there is an intake and an exhaust silencer on the front sides to be attached tightly.

A construction designed according to FIG. 7 makes it possible in the case of a restricted passage profile for vehicles, the interior a maximum size to give, depending on the expansion of the outer shell 33, 34 any size Insulating effect is achievable.

In Fig. 8 is an embodiment of a sound-absorbing double wall shown schematically in which this consists of the two with sound-absorbing liquid filled hollow walls 29 and 30 and a space arranged between them 31 is formed.

With a suitable overlap, the space can also be filled with compressed air be filled, which serves to increase the inherent rigidity of the walls.

The design can also be such that the two walls 29, 30 instead of being filled with liquid with compressed air and the liquid in the space is pumped in between the two walls.

Claims (11)

Claims: 1. Hollow wall for the purpose of sound insulation is filled with liquid, characterized in that the wall shells - for Reduction in volume when transporting without liquid filling - in whole or in part made of flexible foldable material, e.g. B. plastic or rubber exist. 2. Wall according to claim 1, characterized in that the outer Wall shell partly made of flexible, foldable material and the inner wall shell consists of rigid material (Fig. 7). 3. Wall according to claim 1, characterized in that it is below Use of several envelope-shaped, z. B. ring-like elements made of flexible foldable Material is composed (Fig. 1). 4. Wall according to claim 3, characterized. that the envelope-shaped Elements for sealing the I, agerfugen and for mutual engagement z. B. wedge-shaped are profiled (Fig. 2). 5. Wall according to claim 4, characterized in that the elements undercut, e.g. B. have bead profiles (Fig. 3). 6. Wall according to one of claims 1 to 5, characterized in that that the wall surface facing the noise source is wholly or partially sound-absorbing is formed, for. B. by arranging wedge-shaped sound absorbers (Fig. 5 and 6). 7. Wall according to one of claims 1 to 6, characterized in that that to form a window at the point in question, the wall shells made of transparent material and the liquid filling also transparent is. 8. Wall according to claim 1 or one of claims 3 to 7, applied as a soundproof screen, e.g. B. in the form of a hollow cylinder (Fig. 6). 9. Double wall, consisting of two walls according to one of the claims 1 to 8 (Fig. 8). 10. Double wall according to claim 9, characterized in that the space closed between the two walls and with air, if necessary compressed air, is filled out. 11. Cavity wall filled with liquid for the purpose of sound insulation is, characterized in that the two wall shells by inflated covers are formed from flexibly foldable material.