CH713698A2 - Screening. - Google Patents

Abstract

Sieve device (1) having a screen frame (3) spanning a screen surface (2), at least two sound conductors (4-6) and a vibration exciter to vibrate the sound conductors (4-6), the sound conductors (4-6) are coupled via a vibration transformer (10) with the vibration exciter. The sieve frame (3) is covered with a sieve cloth (8). The screen fabric (8) is glued to a sound conductor (4-6) and / or the screen frame (3). In this case, the vibration transmitter (10) comprises a resonator rod (11) to which both sound conductors (4-6) are directly coupled.

Description

Description: The present invention relates to a screening device having a sieve frame spanning a sieve surface and at least two sound conductors and a vibration exciter, wherein the vibration exciter causes the sound conductors to vibrate. For this purpose, the sound conductors are coupled to the vibration exciter.

In the prior art a variety of screening devices have become known. Thus, for the same field of application, for example, mix: DE 4 418 175 C5, a device and a method for screening, classifying, screening, filtering or sorting of substances have become known, wherein a screen area provided in a screen frame and an associated ultrasonic transducer are provided. Due to the ultrasonic transducer vibrations of the sieve surface can be conveyed. The ultrasound transducer is associated with at least one resonator adjoining the screen surface, which resonator is tuned to the resonance of the ultrasound transducer and can be set into oscillations, in particular bending oscillations, by the latter. In this case, at least one concentric annular rod resonator is provided in a circular frame, which is connected to the frame by means of decoupling plates. The decoupling plates are preferably set in a node of the movement. This known device allows a sound distribution over the active screen mesh, wherein in a großflchy screen mesh and a plurality of resonators distributed over the screen mesh can be arranged on-ordered. It is considered disadvantageous in this device that the tuning of the resonator is associated with great expense and can be realized practically only for a few simple resonator geometries.

With the DE 10 2006 037 638 A1 again another device for screening, classifying, filtering or sorting dry tester substances or tester substances in liquids with at least one ultrasonic converter and at least one sound conductor and at least one screen frame is known for the same field of application become, outside of vibration nodes of a nonresonant excited sound conductor or screen frame Verbindungselemen te are attached to at least one screen frame or sound conductor, which are suitable for the transmission of vibration excitation of the sound conductor or screen frame to the screen frame or sound conductor. In the known device, a supply resonator is arranged between the ultrasonic converter and the sound conductor, wherein the Zuleitungsreso-nator is suitable for the excitation of bending vibrations or for the excitation of longitudinal vibrations. Such a device also allows the construction of a screening device with multiple sound conductors to vibrate a larger Siebflche in vibration.

A disadvantage of the known devices, however, is that there is still a significant inequality of vibration excitation over a larger Siebflche with several sound conductors. In particular, arranged more distant from the vibration exciter sound conductors receive less vibration power, whereby in the region of the remote-ren sound conductor only less vibration energy is applied to the mesh. One solution to this problem is to use multiple vibrators, each one exciting a sound conductor to vibrate a particular area of the screen surface. This improves the homogeneity of the transmission of vibrational energy, as it eliminates the need for more distant sound conductors. The disadvantage of this, however, is the expenditure on equipment and also the considerably greater control effort, which results in higher costs.

It is therefore an object of the present invention to provide a screening device available, which allows for less effort a more homogeneous distribution of vibrations on the Siebflche.

This object is achieved by a sieve device having the features of claim 1. Preferred developments of the sieve device according to the invention are the subject of the subclaims. Further advantages and features of the present invention will become apparent from the general description and the description of the Ausführungsbei games.

A screening device according to the invention has at least one screen surface, which is tensioned by a screen frame. Furthermore, at least two sound conductors and a vibration exciter are provided in order to vibrate the sound conductors. The sound conductors are coupled via a vibration transformer with the vibration exciter. In particular, the screen frame is covered with a mesh. The screen fabric is preferably glued to at least one sound conductor and / or the screen frame (3). The vibration transformer comprises a resonator rod to which the two sound conductors (in particular directly and / or directly) are coupled.

The sieve device according to the invention has many advantages. A considerable advantage of the screening device according to the invention is that two or more sound conductors can be vibrated with only one vibration exciter, wherein both sound conductors are coupled to the resonator rod of the vibration contract.

In the prior art, a vibration transformer consists of several Resonatorstâben. If, for example, a circular sieve frame with two (or more) concentrically arranged sound conductor rings is used in a known sieve device, then by means of a vibration transmitter, e.g. transmitted radially from outside the vibration on the derusseren the two sound conductor rings. For this purpose, an external resonator rod is used, which is welded to the outside of the two sound conductor rings on its outside. On the inside of the outer sound conductor ring an inner resonator bar is welded, which is welded to the outer side of the inner sound conductor ring. Thus, in this known system, the vibration was transmitted radially from the outside of the vibration exciter on the outer resonator (the weld) on the outer sound conductor ring and from there (via the inner weld and) on the inner resonator again on the weld on the inner sound conductor ring. It has been found that these per se very stiff and strong welded joints transmit or even absorb a substantial part of the vibrational energy out of phase. In any case, such a system of several resonator bars, welding seams and sound conductor rings only transfers the excited oscillation frequency to more distant sound conductors to a considerably weaker extent or at least not lossless.

In the present invention, in contrast, now the vibration of the Resonatorstabes practically un-indirectly transmitted from the Resonatorstab each on both sound conductors. This avoids a different number of material transitions. Thus, it is not necessary to transfer the vibration power for the farthest sound conductor over several weld seams and sound conductor rings, but the vibration energy is transmitted from the resonator directly to the one sound conductor and the other sound conductor (and possibly further sound conductors).

In a preferred embodiment, the screening device comprises a screen frame and at least partially provided thereon Siebflche, wherein the screen frame is designed and designed to be biased with a mesh, wherein the screen frame is assigned a vibration exciter and wherein the vibration exciter with a plurality of sound conductors is connected. In this case, the vibration generator is coupled via a continuous vibra tion transmitter with preferably at least two sound conductor rings.

In preferred embodiments, the resonator rod is solid. It is also possible that the resonator rod is hollow.

The resonator can be configured as a polygonal rod, rectangular rod or preferably as a round rod. It is also possible that the resonator rod has an O, T, X, L, V or U-shaped or elliptical or other suitable cross-section. In particular, the cross section of the resonator rod is adapted to the oscillation frequency to be transmitted or the oscillation frequency range to be transmitted.

In preferred embodiments of the resonator with the sound conductors is positively and / or kraftschlüs-sig (fixed) connected. In particularly preferred developments, the resonator rod is connected to the sound conductors both positively and non-positively.

In advantageous developments of the sound conductor is welded to the resonator or soldered or glued. In particular, it is preferred that the resonator rod has at least one recess for the positive reception of a sound conductor. Such in a recess positively received sound conductor on the resonator allows a particularly efficient transmission of vibrations to the sound conductor. The sound conductor is in particular pressed into the recess.

In a particularly preferred embodiment, the recess is formed in an upper part of the Resonatorstabes and serves for the positive reception of a lower part of a sound conductor. Under "below" and "above" here are the directions in the intended assembly and the intended use to understand. It is also possible, however, for the recess to be formed in a lower part of the resonator rod and for the positive reception of an upper part of a sound conductor.

Preferred embodiments are those in which the recesses are provided in an upper part of the resonator rod, since these embodiments allow the simple possibility that the resonator rod is arranged partially below the sound conductor. This is a structurally simpler embodiment, since typically the screen mesh is arranged directly above the sound conductor, to which the sound conductors are transmitted the vibration.

In all embodiments, it is also possible that the recess is formed in a right or left part of the Resonatorstabes and therein a part of the sound conductor is positively received in a manner analogous to the vibrations acting in the Resonatorstab reliably and efficiently to the sound conductor and in particular to transmit the sound conductors. It is also possible that a e.g. formed as a ring sound conductor has a downwardly projecting extension to which the resonator rod (from below, the side or an upper surface) is coupled. The extension is in particular formed integrally with the rest of the sound conductor or can be formed as a séparâtes part and firmly connected to the sound conductor and z. B. be welded. If all the sound conductors are connected to the resonator rod in the same way, the desired uniform excitation of all sound conductors is achieved.

In all embodiments, it is possible to designate the vibration transformer as a feed resonator.

Preferably, the resonator has two or more recesses for the positive recording of a respective sound conductor. With spiral-shaped sound conductors, it is also possible for the resonator rod to have two or more recesses for a single sound conductor.

In preferred developments, the resonator rod passes through the screen frame without contact. Preferably, for this purpose, a passage opening is formed on the screen frame, by means of which the resonator rod is carried out without contact. This achieves a decoupling of the resonator rod from the screen frame, so that a particularly efficient transmission of the vibrations to the screen fabric is possible.

It is also possible in other embodiments, that the resonator is guided below the screen frame to the sound conductors. Then a through-opening is not necessary.

In all embodiments, the resonator rod is preferably arranged in the region of the sound conductor in a plane which is arranged offset in height to a plane of Durchgangsoffnung or a middle level of the screen frame. This means that the resonator rod does not extend completely within a plane parallel to the plane of the screen fabric and / or the plane of the screen frame, but that a part of the resonator rod is preferably in a first plane and another part of the resonator rod in a second and high-offset plane extends. As a result, a small-sized sieve device is made possible. The construction volume is used optimally. The screen frame does not have to be made higher than necessary. The supply of the vibrations via the resonator rod can take place at the height of the sieve frame and through the sieve frame, while the resonator rod is preferably located somewhat lower in the region of the sound conductors and is coupled there to the sound conductors. Or the supply of vibrations takes place below the screen frame. Preferably, the resonator rod is bent twice between the screen frame and a first sound conductor (in particular in opposite directions). Particularly preferably, the two bends are designed such that the resonator rod is located in the region of the passage through the screen frame and in the region of the sound conductor in each case in two vertically offset planes. If the resonator rod is arranged below the sieve frame and does not pass through the sieve frame, the resonator rod is preferably also deflected twice, wherein the resonator rod in the region of the sieve frame is then preferably arranged lower than in the region of the sieve surface.

In all embodiments, it is preferred that at least one sound conductor is designed as a closed sound conductor ring. Such a sound conductor ring may have a rectangular or elliptical or circular shape or other shape. Preferred are rectangular shapes or rectangular shape, with rounded corners or circular shapes. Such a configuration allows a homogeneous distribution of the vibration energy on the Siebflche.

A sound conductor may have a polygonal and in particular approximately rectangular cross-section in all embodiments. It is also possible that the sound conductor has a T, X, L or U-shaped or elliptical cross section. In preferred embodiments, the different sound conductors have a (substantially) same cross-section.

Particularly preferred at least one sound conductor is designed as a hollow profile.

Preferably, at least one sound conductor is connected to another sound conductor and / or the screen frame via at least one connecting element and in particular a plurality of connecting elements. The connecting elements can preferably be fixed in a nodal point of the movement. However, the connecting elements can also be used for transmitting vibration energy to the screen frame.

Preferably, the screen frame is covered with at least one screen fabric. It is preferred that the screen fabric is glued to at least one sound conductor and / or the screen frame. The mesh may comprise two or more layers of fabric.

In all embodiments, it is particularly preferred that the vibration exciter comprises at least one ultrasonic converter or is designed as an ultrasonic converter. In particular, the ultrasonic converter has a (working) frequency between 10 kHz and 50 kHz. Preferably, the ultrasonic converter has a frequency of 10-40 kHz, and preferably between 20 and 40 kHz.

It is preferred that the ultrasonic converter (at least) has a frequency between 30 kHz and 40 kHz. Preferably, the frequency can be changed during operation, so that, in particular, periodically changing frequencies are possible during operation.

Advantageously, the vibration exciter is mounted outside the Siebflche.

In other preferred embodiments, the vibration exciter (or at least one vibration exciter) is mounted within the screen surface and preferably above the screen surface. It is also possible that the vibration exciter is mounted below the Siebflche. In particular, the vibration exciter is arranged in such embodiments within a projection perpendicular to the Siebflche.

In preferred developments of all embodiments, at least one second vibration exciter and an associated second resonator rod are provided. Preferably, a second vibration exciter and an associated second resonator rod (in particular geometrically) are arranged opposite to the first system (vibration exciter + resonator rod). In even more systems, uniform distribution becomes e.g. over the circumference preferred.

In further refinements and developments, the type of vibration excitation and the application of the vibrations to the screen fabric can take place, as disclosed in DE 10 2006 037 638 A1 and / or DE 4 418 175 C5.

Further advantages and features of the present invention will become apparent from the embodiments which will be explained in the following with reference to the accompanying figures.

In the figures:

1 shows a slightly perspective top view of a sieve device according to the invention;

FIG. 2 shows a schematic partial cross section through the screening device according to FIG. 1; FIG.

Fig. 3 is an enlarged detail of Fig. 1;

4 shows a plan view of a further embodiment of a screening device according to the invention;

5 shows a schematic cross section through the vibration transmitter of the screening device according to FIG. 4; and FIG. 6 shows a top view of yet another embodiment of a screening device according to the invention.

The sieve device 1 according to the invention, which is shown in FIGS. 1 to 3, has a sieve surface 2 on a sieve frame 3, which is covered with a sieve cloth 8. Of the screen fabric 8 is here for the sake of clarity (as in the other embodiments each maximum) only a small portion shown schematically.

In this here approximately circular sieve frame 3 of the sieve 1 concentric to each other three here also circular sound conductors 4, 5 and 6 are arranged, which are offset via a vibration transformer 10 by the only visible in Fig. 3 vibration exciter 7 in oscillation.

The vibration transformer 10 comprises a resonator rod 11 which is performed without contact by the sieve frame 3 on the receptacle 29 and which is connected directly to the sound conductors 4, 5 and 6.

The resonator rod 11 is made here in one piece and is directly and directly connected to the sound conductors 4, 5 and 6, so that the vibration energy that is introduced by the vibration exciter 7 in the resonator 11, each directly from the resonator 11 to the respective sound conductor 4, 5 and 6 is transmitted. In contrast to the prior art, there is no transmission from one resonator rod to a sound conductor and from there again to the next resonator rod, etc., but the vibrations are respectively transmitted directly from the resonator rod to the sound conductor.

However, it is conceivable in all embodiments and configurations to use two resonator rods, wherein a first resonator rod transmits the vibrations from the vibration generator to a first surface of a first sound conductor (for example radially outward). From a second surface of the first sound conductor (for example the inside of the first sound conductor or the opposite outside), the vibrations are then transmitted via the second resonator rod to another sound conductor. Even with such an embodiment, it is ensured that a homogeneous excitation of all sound conductors takes place, even if the total energy input is not quite as high as in a single one due to the use of the two separate resonator bars.

The individual sound conductors are connected via connecting elements 22 and 23 with each other and / or with the frame 3. In this case, the connecting elements 22 extend between the outer sound conductor 4 and the screen frame 3. The connecting elements 23 each extend between the sound conductors 4 and 5 or 5 and 6.

About the connecting elements 22 and 23 can - depending on the needs and structural design - a decoupling ment of the vibrations of the sound conductors and the screen frame 3 done. If necessary, the screen frame 3 can be set in vibration.

As can be seen in Fig. 1 and Fig. 3, the resonator rod 11 via the holder 28 with. connected to the screen frame 3 such that a vibration in the longitudinal direction of the resonator rod is made possible, while the resonator rod is kept defined in the transverse direction to the Longer.

FIG. 2 shows a radial partial cross section through the screening device 1 from FIG. 1, wherein the screen fabric 8 extends above the sound conductors 4, 5 and 6 and the screen frame 3. The sound conductors 4, 5 and 6 are formed here as a circular sound conductor rings and each have the cross section of a hollow rod. The cross-section of the sound conductors 4, 5 and 6 is approximately rectangular, wherein the rectangle has an elongated shape and extends in the vertical direction transversely to the resonator rod longer than in the direction of the resonator rod.

The resonator rod 11, which essentially forms the vibration transformer 10, here has three Aussparun gene 13, in which the sound conductors 4, 5 and 6 are each recorded. Preferably, the recesses 13 are designed positively, so that the sound conductors are 4.5 and 6 are particularly preferably pressed into the recesses. For further improvement of the sound transmission, welding seams 25 are preferably provided with which the sound conductors 4, 5 and 6 are respectively welded to the rod material of the resonator rod 11.

The recesses are preferably in the upper part 14 of the Resonatorstabes 11 and here (about) in the upper half of the Resonatorstabes 11. Accordingly, the sound conductors 4, 5 and 6 are each received with its lower part 15 in the recesses 13.

It is also conceivable that the recesses are formed in the lower part of the Resonatorstabes and therein a oberer part or part of the sound conductor is accommodated.

The resonator rod 11 has in cross-section according to FIG. 2 two bends 20 and 21, which provide for a parallel offset of the two longitudinal sections of the resonator rod 11. In the region of the through-opening 9 through the screen frame, the resonator rod 11 is arranged in the plane 19, while the resonator rod 11 in the region of

Sound conductor 4 to 6 extends in a plane 18 which is elevated to the plane 19. The height offset is dimensioned such that the sound conductors 4 to 6 are received from below in the recesses 13 of the resonator rod 11. The height offset is here between 1/5 and 2/3 of the height of a sound conductor and in particular about half the height (+/- 10%) of the height of the Resonatorstabs 11. Also a feed below the screen frame is possible, and then one regularly also (reverse) height offset.

Fig. 3 shows a detail of Fig. 1 in a plan view, wherein the region of the passage opening 9 for the resonator torstab 11 is shown in a horizontal cross-section. The resonator rod 11 passes through the passage opening 9 without contact and is held by the holder 28, wherein the holder 28 vibrations in the longitudinal direction of the Resonatorstabes not or only very little attenuates.

The vibration exciter 7, which is shown in dashed lines in Fig. 3 only schematically as a black box, can be mounted on the receptacle 29 and transmäggt the vibrations generated on the vibration transformer 10 and the resonator 11, which is designed here as a round rod 12 and made of solid material.

The resonator rod 11 is preferably made of metal and in particular of steel and preferably also high-alloy steel (stainless steel).

The sound conductors 4 to 6 are preferably also made of metal and in particular of a light metal such as an aluminum alloy or of other light metals. In the concrete example, a hollow profile made of stainless steel is used.

4 shows a further embodiment of a screening device according to the invention, in which the connection of the sound conductors 4 to 6 to the resonator rod 11 of the vibration transformer 10 is realized differently than in the embodiment according to FIGS. 1 to 3.

The basic embodiment of the screening device i according to FIG. 4 corresponds to the embodiment of the screening device according to FIG. 1. Here, too, the screening device 1 is designed to be approximately circular in shape and has three concentric sound conductors 4 to 6, each of which is arranged concentrically with one another are and are formed as a sound conductor 24. The respective sound conductors 4 to 6 are connected via connecting elements 22 and 23 respectively to the screen frame 3 and to the other sound conductors.

In addition, a cross-shaped stabilization 27 is shown in FIG. 4, which extends below the screen surface and serves to stabilize the screen frame 3.

The resonator rod 11 of the vibration transmitter, which is likewise embodied in one piece here, in turn extends in one piece and without contact through the sieve frame 3 and is firmly coupled to the sound conductors 4, 5 and 6.

FIG. 5 shows a schematic radial cross section through the resonator rod 11 in the embodiment according to FIG. 4.

In the illustrated embodiment, the resonator rod 11, in contrast to the embodiment according to FIGS. 1 to 3 no recesses 13. In contrast, the respective sound conductors 4 to 6 are provided with a passage 26 in the form of a passage opening or bore, through which the resonator rod 11 is passed. For the firm connection of the sound conductors 4 to 6 with the resonator rod 11, the sound conductors A to 6 are connected at the suitable position to the resonator rod 11 via (preferably here) double-sided welding seams 25. This also results in a test coupling of the sound conductors 4 to 6 with the resonator rod 11. Again, the sound conductors 4 to 6 are each directly and directly coupled to the resonator 11, so that a power-reducing coupling of the distant sound conductor 5 or 6 is avoided.

6 shows a schematic plan view of a further embodiment of a screening device 1 according to the invention, in which case a rectangular screen frame 3 is used, on which two sound conductors 4 and 5, which are also rather rectangular, are provided. It is also possible that three or more sound conductors are arranged in one another or arranged one behind the other.

The sound conductors 4 and 5 are connected via connecting elements 22 to the frame 3. To excite the sound conductors 4 and 5 is a Schwingungsüberträgers 10, which here again comprises a one-piece and continuous resonator rod 11 which extends from the outside through the passage opening 9 and the vibrations on the sound conductors 4 and 5 transmagt.

In this case, the one-piece resonator rod 11 may extend through bushings 26 on the sound conductor 4 and on the sound conductor 5 to the rear end of the sound conductor 5, as shown in principle Fig. 5 shows. However, the sound conductors 4 and 5 can also be connected to the resonator rod 11 via a connection type as in FIG. 2.

In both variants, the sound conductors 4 and 5 may be connected to the resonator rod 11 only at the front (rear) ends, respectively, as indicated by the solid (dashed) arrows at 25 in FIG. 6, or The sound conductors 4 and 5 are connected to the resonator rod 11 via welding seams 25 and / or recesses 13 at respectively the front and the rear end of a sound conductor 4 and 5.

In all embodiments, screening devices with a diameter or a length of up to 2650 mm or even 2900 mm or 4000 mm and more can be provided. Such screening devices enable particularly effective processing of, for example, metal powders, colored powders, fine minerals, bronze powders or aluminum powders, quartz sand and other particles in a size of up to 500 μm or 1000 μm or finer.

A screening device according to the invention enables a more homogeneous distribution of power and a greater power input, which can be locally 10% or 20% or even more.

To connect the resonator rod 11 to the sound conductors 4 to 6etc. In addition to, or instead of positive locking, welding, screwing, gluing, soldering, pressing or any other joining method may be used.

In all embodiments, it is possible that the screen mesh is glued to the frame. But it is also possible that the mesh fabric rests on the frame only and is glued only to the sound conductors 4 to 6.

At least one frequency in the range 30 to 38 kHz is preferably used as the excitation frequency. It is also possible to use two or more parallel excitation frequencies (frequency ranges) or two or more different excitation frequencies one after the other.

Especially in the explosion-proof field of application, the invention has great advantages. A better screening result and a better distribution of the products to be boiled are achieved. Also, a longer life can be achieved. This is, among other things, that a more homogeneous introduction of the vibration power is achieved. A more uniform distribution of the energy (ultrasonic energy) is achieved and thus fewer hotspots are produced, which is very advantageous, especially in the explosion-proof field of application.

LIST OF REFERENCES [0070] 1 sieve device 2 sieve surface 3 sieve frame 4 sound conductor 5 sound conductor 6 sound conductor 7 oscillation exciter 8 sieve fabric 9 through opening 10 vibration transmitter 11 resonator rod 12 round bar 13 recess 14 ober part of 11 15 lower part of 4 18 plane 19 plane of 9 20 bend 21 bend 22 Connecting element 23 Connecting element 24 Sound conductor ring 25 Weld seam 26 Conduction 27 Stabilization 28 Holder of 11 29 Recording 30 Ultrasonic converter

A screening device (1) comprising a screen frame (3) spanning a screen surface (2), at least two sound conductors (4-6) and a vibration exciter (7) for vibrating the sound conductors (4-6), the sound conductors ( 4-6) via a vibration transformer (10) are coupled to the vibration exciter (7), characterized in that the sieve frame (3) is covered with a sieve cloth (8) and that the sieve cloth (8) with at least one sound conductor (4). 6) and / or the screen frame (3) is glued and that the vibration transformer (10) comprises a resonator rod (11) to which the two sound conductors (4-6) are coupled. 2. Screening device according to the preceding claim, wherein the resonator rod (11) is solid or hollow and / or wherein at least one sound conductor (4-6) is formed as a hollow profile. 3. Screening device according to one of the preceding claims, wherein the resonator rod (11) as a polygonal bar, right-eckstab or round rod (12) is formed, wherein the resonator rod (11) preferably an O, T, X, L, U- or V-shaped cross-section. 4. Screening device according to one of the preceding claims, wherein the resonator rod (11) with the sound conductors (4-6) is positively and / or non-positively connected. 5. Screening device according to one of the preceding claims, wherein at least one sound conductor (4-6) welded to the resonator rod (11) or is soldered or glued. 6. Screening device according to one of the two preceding claims, wherein the resonator rod (11) has at least one recess (13) for the positive reception of a sound conductor (4-6) and wherein the resonator rod (11) in particular two or more recesses (13) for positive locking Recording each having a sound conductor (4-6). 7. Screen device according to the preceding claim, wherein the recess (13) in an upper part (14) of the re-sonatorstabes (11) is formed and wherein therein a lower part (15) of a sound conductor (4-6) positively received or wherein the recess (13) is formed in a lower part of the resonator rod (11) and wherein a part of a sound conductor (4-6) is received therein. 8. Screening device according to one of the preceding claims, wherein the resonator rod (11) passes through the screen frame (3) at a passage opening (9) without contact and / or wherein the resonator rod (11) below the Siebrah-men (3) to the sound conductors (4 -6) is performed. A screening device according to the preceding claim, wherein the resonator rod (11) extends in the region of the sound conductors (4-6) in a plane (18) which is arranged offset in height to a plane (19) of the through-opening (9) and wherein Resonator rod (11) in particular between the screen frame (3) and a first sound conductor (4) is bent twice. 10. Screening device according to one of the preceding claims, wherein at least one sound conductor (4-6) as a closed-sound conductor ring (24) is formed and wherein the sound conductor ring (24) in particular has a rectangular or elliptical shape or a circular shape and / or wherein the sound conductor (4-6) has a polygonal or rectangular or T, X, L or O-shaped or U-shaped or elliptical cross-section. 11. Screening device according to one of the preceding claims, wherein at least one sound conductor (4) with another sound conductor (5) and / or the screen frame (3) via connecting elements (22, 23) is connected. 12. Screening device according to one of the preceding claims, wherein the screen fabric (8) comprises two or more tissue layers. 13. Screening device according to one of the preceding claims, wherein the vibration exciter (7) comprises at least one ultrasonic converter (30) and wherein the ultrasonic converter (30) preferably has a frequency between 10 kHz and 50 kHz. 14. Screen device according to one of the preceding claims, wherein the frame has a passage opening (9) for the vibration transmitter (10) and wherein the vibration exciter (7) outside the Siebflche (2) ange-

Claims (15)

25 Welded seam 26 Conduction 27 Stabilization 28 Holder of 11 29 Holder 30 Ultrasonic converter Claims A screening device (1) comprising a screen frame (3) spanning a screen surface (2), at least two sound conductors (4-6) and a vibration exciter (7) for vibrating the sound conductors (4-6), the sound conductors (4 6) are coupled to the vibration exciter (7) via a vibration transmitter (10), characterized in that the sieve frame (3) is covered with a sieve cloth (8) and that the sieve cloth (8) is provided with at least one sound conductor (4-6 ) and / or the screen frame (3) is glued and that the vibration transformer (10) comprises a resonator rod (11) to which the two sound conductors (4-6) are coupled. 2. Screening device according to the preceding claim, wherein the resonator rod (11) is solid or hollow and / or wherein at least one sound conductor (4-6) is formed as a hollow profile. 3. Screening device according to one of the preceding claims, wherein the resonator rod (11) as a polygonal bar, right-eckstab or round rod (12) is formed, wherein the resonator rod (11) preferably an O, T, X, L, U- or V-shaped cross-section. 4. Screening device according to one of the preceding claims, wherein the resonator rod (11) with the sound conductors (4-6) is positively and / or non-positively connected. 5. Screening device according to one of the preceding claims, wherein at least one sound conductor (4-6) welded to the resonator rod (11) or is soldered or glued. 6. Screening device according to one of the two preceding claims, wherein the resonator rod (11) has at least one recess (13) for the positive reception of a sound conductor (4-6) and wherein the resonator rod (11) in particular two or more recesses (13) for positive locking Recording each having a sound conductor (4-6). 7. Screen device according to the preceding claim, wherein the recess (13) in an upper part (14) of the re-sonatorstabes (11) is formed and wherein therein a lower part (15) of a sound conductor (4-6) positively received or wherein the recess (13) is formed in a lower part of the resonator rod (11) and wherein a part of a sound conductor (4-6) is received therein. 8. Screening device according to one of the preceding claims, wherein the resonator rod (11) passes through the screen frame (3) at a passage opening (9) without contact and / or wherein the resonator rod (11) below the Siebrah-men (3) to the sound conductors (4 -6) is performed. A screening device according to the preceding claim, wherein the resonator rod (11) extends in the region of the sound conductors (4-6) in a plane (18) which is arranged offset in height to a plane (19) of the through-opening (9) and wherein Resonator rod (11) in particular between the screen frame (3) and a first sound conductor (4) is bent twice. 10. Screening device according to one of the preceding claims, wherein at least one sound conductor (4-6) as a closed-sound conductor ring (24) is formed and wherein the sound conductor ring (24) in particular has a rectangular or elliptical shape or a circular shape and / or wherein the sound conductor (4-6) has a polygonal or rectangular or T, X, L or O-shaped or U-shaped or elliptical cross-section. 11. Screening device according to one of the preceding claims, wherein at least one sound conductor (4) with another sound conductor (5) and / or the screen frame (3) via connecting elements (22, 23) is connected. 12. Screening device according to one of the preceding claims, wherein the screen fabric (8) comprises two or more tissue layers. 13. Screening device according to one of the preceding claims, wherein the vibration exciter (7) comprises at least one ultrasonic converter (30) and wherein the ultrasonic converter (30) preferably has a frequency between 10 kHz and 50 kHz. 14. Screening device according to one of the preceding claims, wherein the frame has a passage opening (9) for the vibration transmitter (10) and wherein the vibration exciter (7) outside the Siebflche (2) is attached or wherein the vibration exciter (7) within the Siebflche (2) and preferably above the sieve surface (2) is mounted. 15. Screen device according to one of the preceding claims, wherein at least a second vibration exciter and an associated second resonator rod are provided.