DE102017106930A1 - screening - Google Patents

Abstract

Screen device (1) having a screen frame (3) spanning a screen surface (2), at least two sound conductors (4-6) and a vibration exciter (7) to vibrate the sound conductors (4-6), the sound conductors (4 -6) are coupled via a vibration transformer (10) with the vibration exciter (7). In this case, the vibration transmitter (10) comprises a resonator rod (11) to which both sound conductors (4-6) are directly coupled.

Description

The present invention relates to a screening device with a screen frame spanning a screen surface and at least two sound conductors and a vibration exciter, wherein the vibration exciter vibrates the sound conductor. For this purpose, the sound conductors are coupled to the vibration exciter.

In the prior art a variety of screening devices have become known. So are for the same field of application, for example, with the DE 44 18 175 C5 a device and a method for screening, classifying, sifting, filtering or sorting of substances has become known, wherein a sieve frame provided in a screen surface and an associated ultrasonic transducer are provided. By the ultrasonic transducer of the screen surface vibrations are zuleitbar. The ultrasound transducer is assigned at least one resonator resting against the sieve 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 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 large screen mesh and several resonators can be arranged distributed over the mesh. 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 03763 8 A1 In turn, for the same field of application another device for screening, classifying, filtering or sorting dry solids or solids in liquids with at least one ultrasonic converter and at least one sound conductor and at least one screen frame has become known, being outside of nodes of a nonresonant excited sound conductor or Sieve frame connecting elements 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 feed resonator is arranged between the ultrasound converter and the sound conductor, wherein the feed resonator is suitable for exciting bending vibrations or for exciting longitudinal oscillations. Such a device also allows the construction of a screening device with multiple sound conductors to vibrate a larger screen area.

A disadvantage of the known devices, however, is that there is still a significant inequality of vibration excitation over a larger screen area with multiple sound conductors. In particular, sound conductors disposed farther from the vibration generator receive less vibration power, whereby only a small amount of vibration energy is applied to the screen mesh in the area of the remote sound conductor. One solution to this problem is to use multiple vibrators, each with a vibrator energizing a sound conductor to vibrate a certain area of the screen surface. As a result, the homogeneity of the transmission of vibration energy is improved, since it is possible to dispense with more distant sound conductors. The disadvantage of this, however, are the expenditure on equipment and also the considerably greater control effort, which results in higher costs.

It is therefore the object of the present invention to provide a screening device which enables a more homogeneous distribution of the vibrations on the screen surface with less effort.

This object is achieved by a screening device with the features of claim 1. Preferred developments of the screening device according to the invention are the subject of the dependent claims. Further advantages and features of the present invention will become apparent from the general description and the description of the embodiments.

A screening device according to the invention has at least one screen surface, which is clamped 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. The vibration transmitter comprises a resonator rod to which the two sound conductors (in particular directly and / or directly) are coupled.

The screening device according to the invention has many advantages. A significant advantage of the screening device according to the invention is that two or more sound conductors are 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 resonator rods. If, for example, a circular sieve frame with two (or more) concentrically arranged thereon Schallleiterringen used in a known screening device, it is via a vibration transformer z. B. transmitted radially from the outside of the vibration on the exterior of the two sound conductor rings. For this purpose, an outer resonator rod is used, which is welded to the exterior of the two sound conductor rings on the outside thereof. On the inside of the outer sound conductor ring, an inner resonator rod 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 via the weld on the inner sound conductor ring. It has been found that these per se very stiff and strong welds pass on a significant portion of the vibrational energy out of phase or even absorb. In any case, such a system of several resonator rods, welds and sound conductor rings transmits the excited oscillation frequency to more distant sound conductors only to a considerably weaker extent or at least not without loss.

In contrast, in the present invention, the oscillation of the resonator rod is transmitted to both sound conductors practically immediately from the resonator rod. This avoids a different number of material transitions. Thus, it is not necessary to transfer the vibration power for the farthest sound conductor over a plurality of welds 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 optionally further sound conductors).

In a preferred embodiment, the sieve device comprises a sieve frame and a sieve surface provided at least partially thereon, wherein the sieve frame is provided and designed to be covered with a sieve cloth, wherein the sieve frame is associated with a vibration exciter and wherein the oscillation exciter is connected to a plurality of sound conductors is. In this case, the vibration exciter is coupled via a continuous vibration transformer with preferably at least two sound conductor rings.

In preferred embodiments, the resonator rod is solid. It is also possible that the resonator 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 developments, the resonator rod is connected to the sound conductors in a form-fitting and / or non-positive (fixed) manner. In particularly preferred developments, the resonator rod is connected to the sound conductors both positively and non-positively.

In advantageous developments, the sound conductor is welded or soldered or glued to the resonator rod. 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 development, the recess is formed in an upper part of the resonator rod 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. But it is also possible that the recess is formed in a lower part of the resonator and serves 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 open up the simple possibility that the resonator rod is arranged partly 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 in a similar manner a part of the sound conductor is positively received to the vibrations acting in the Resonatorstab vibrations reliably and efficiently to the sound conductor and in particular the To transmit sound conductor. It is also possible that a z. B. trained as a ring sound conductor after having downwardly projecting extension to which the resonator rod (bottom, side or top surface) is coupled. The extension is in particular formed integrally with the rest of the sound conductor or can be formed as a separate part and firmly connected to the sound conductor and z. B. welded. If all the sound conductors are connected in the same way to the resonator rod, the desired uniform excitation of all sound conductors is thus achieved.

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

Preferably, the resonator rod has two or more recesses for the positive reception of a respective sound conductor. In spirally formed sound conductors, it is also possible that the resonator has two or more recesses for a single sound conductor.

In preferred developments, the resonator rod passes through the screen frame without contact. For this purpose, a passage opening is preferably 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 rod is guided below the screen frame to the sound conductors. Then a through hole 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 the passage opening or a middle plane 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 height offset plane extends. This enables a small-sized screening device. The construction volume is used optimally. The screen frame does not have to be made higher than necessary. The supply of vibrations through the resonator can be done in height of the screen frame and through the screen frame, while the resonator preferably in the region of the sound conductor is slightly deeper and is coupled there with 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 bar 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 planes arranged offset in height. 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 screen surface.

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 preferably, 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 defined in a node 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 generator 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 preferable that the ultrasonic converter has (at least) a frequency between 30 kHz and 40 kHz. Preferably, the frequency is variable during operation, so that in particular periodically changing frequencies are possible during operation.

Advantageously, the vibration exciter is mounted outside the screen surface.

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 screen surface. In particular, the vibration exciter is arranged in such embodiments within a projection perpendicular to the screen surface.

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, a uniform distribution z. B. over the circumference.

In other embodiments and developments, the type of vibration excitation and the application of the vibrations can be done on the mesh, as in the DE 10 2006 037 638 A1 and / or the DE 44 18 175 C5 is disclosed.

Further advantages and features of the present invention will become apparent from the embodiments, which are explained below with reference to the accompanying figures.

• 1 eine leicht perspektivische Draufsicht auf eine erfindungsgemäße Siebeinrichtung;
• 2 einen schematischen Teilquerschnitt durch die Siebeinrichtung gemäß 1;
• 3 ein vergrößertes Detail aus 1;
• 4 eine Draufsicht auf ein weiteres Ausführungsbeispiel einer erfindungsgemäßen Siebeinrichtung;
• 5 einen schematischen Querschnitt durch den Schwingungsübertrager der Siebeinrichtung gemäß 4; und
• 6 eine Draufsicht auf noch ein Ausführungsbeispiel einer erfindungsgemäßen Siebeinrichtung.

In the figures show:

• 1 a slightly perspective top view of a screening device according to the invention;
• 2 a schematic partial cross section through the screening device according to 1 ;
• 3 an enlarged detail 1 ;
• 4 a plan view of another embodiment of a screening device according to the invention;
• 5 a schematic cross section through the vibration transformer of the screening device according to 4 ; and
• 6 a plan view of yet another embodiment of a screening device according to the invention.

The screening device according to the invention 1 that in the 1 to 3 is shown, has a screen surface 2 on a sieve frame 3 on that with a screen cloth 8th is covered. From the mesh 8th Here is the sake of clarity (as in the other embodiments each maximum) only a small section shown schematically.

In this approximately circular screen frame 3 the screening device 1 are concentric to each other three here also circular sound conductor 4 . 5 and 6 arranged, via a vibration transformer 10 by the only in 3 recognizable vibration exciter 7 be vibrated.

The vibration transmitter 10 includes a resonator rod 11 that is non-contact through the screen frame 3 at the reception 29 is performed and the directly with the sound conductors 4 . 5 and 6 connected is.

The resonator rod 11 is here made in one piece and is directly and directly with the sound conductors 4 . 5 and 6 connected, so that the vibration energy generated by the vibration exciter 7 in the resonator rod 11 is introduced, each directly from the resonator 11 on 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 all sound conductors.

However, it is also 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 (eg radially outward). From a second surface of the first sound conductor (eg, the inside of the first sound conductor or the opposite outside), the vibrations are then transmitted via the second resonator rod to all other sound conductors. Even with such an embodiment, it is ensured that a homogeneous excitation of all sound conductors takes place, even if the energy input as a whole is not quite as high as in a single one due to the use of the two separate resonator rods.

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

About the fasteners 22 and 23 can - depending on needs and structural design - a decoupling of the vibrations of the sound conductors and the screen frame 3 respectively. If necessary, the screen frame 3 be vibrated.

As in 1 and 3 recognizable, is the resonator rod 11 over the holder 28 with the sieve frame 3 connected in such a way that oscillation in the longitudinal direction of the resonator rod is made possible while the resonator rod is kept defined transversely to the longitudinal extent.

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

The resonator rod 11 , which is essentially the vibration transformer here 10 forms, here has three recesses 13 on where the sound conductor 4 . 5 and 6 are each recorded. Preferably, the recesses 13 designed form-fitting, so that the sound conductor 4 . 5 and 6 particularly preferably are pressed into the recesses. To further improve the sound transmission are preferably welds 25 provided with which the sound conductor 4 . 5 and 6 in each case with the rod material of the resonator rod 11 are welded.

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

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

The resonator rod 11 has in cross section according to 2 two bends 20 and 21 on, for a parallel offset of the two longitudinal sections of the Resonatorstabes 11 to care. In the area of the passage opening 9 through the screen frame is the resonator rod 11 in the plane 19 arranged while the resonator rod 11 in the field of sound conductors 4 to 6 in a plane 18 extends, the height offset to the plane 19 is. The height offset is such that the sound conductor 4 to 6 from below in the recesses 13 of the resonator rod 11 are included. 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 supply below the screen frame is possible, in which case there is also a regular (reverse) height offset.

3 shows a detail 1 in a plan view, wherein the region of the passage opening 9 for the resonator rod 11 is shown in a horizontal cross-section. The resonator rod 11 passes through the passage opening 9 non-contact and will be through the holder 28 held, the holder 28 Vibrations in the longitudinal direction of the Resonatorstabes not or only very little attenuates.

The vibration generator 7 who in 3 only schematically shown in dashed lines as a black box, can on the recording 29 be mounted and transmits the vibrations generated on the vibration transformer 10 or the resonator rod 11 who is here as a round rod 12 is formed 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 conductor 4 to 6 are preferably also made of metal and in particular of a light metal such as an aluminum alloy or 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 conductor 4 to 6 to the resonator rod 11 of the vibration transmitter 10 is realized differently than in the embodiment according to the 1 to 3 ,

The basic design of the screening device 1 according to 4 corresponds to the embodiment of the screening device according to 1 , Again, the screening device 1 overall approximately circular and has three concentric sound conductors 4 to 6 on, which are each arranged concentrically to each other and as Schallleiterringe 24 are formed. The respective sound conductors 4 to 6 are about fasteners 22 and 23 each with the screen frame 3 or connected to the other sound conductors.

Additionally is in 4 a cross-shaped stabilization 27 represented, which extends below the screen surface and to stabilize the screen frame 3 serves.

The here also integrally formed vibration transformer 10 or the resonator rod 11 the Schwingungsübertragers extends again in one piece and without contact through the sieve frame 3 and is stuck with the sound conductors 4 . 5 and 6 coupled.

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

In the illustrated embodiment, the resonator rod 11 in contrast to the embodiment according to 1 to 3 no recesses 13 on. In contrast to this, the respective sound conductors 4 to 6 with a passage 26 provided in the form of a through hole or a bore through which the resonator rod 11 is performed. For the firm connection of the sound conductors 4 to 6 with the resonator rod 11 become the sound conductors 4 to 6 at the appropriate position with the resonator rod 11 over (here preferably) double-sided welds 25 connected. This also results in a solid coupling of the sound conductor 4 to 6 with the resonator rod 11 , Again, the sound conductors 4 to 6 each directly and directly with the resonator rod 11 coupled, so a performance-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 according to the invention 1 , here a rectangular trained screen frame 3 is used, at the two also more rectangular trained sound conductor 4 and 5 are provided. It is also possible that three or more sound conductors are provided in one another or arranged one behind the other.

The sound conductor 4 and 5 are about fasteners 22 with the frame 3 connected. To stimulate the sound conductor 4 and 5 serves a vibration transmitter 10 , here again a one-piece and continuous resonator rod 11 includes, extending from the outside through the passage opening 9 extends and the vibrations on the sound conductor 4 and 5 transfers.

In this case, the one-piece resonator rod 11 through ducts 26 on the sound conductor 4 and on the sound conductor 5 to the back end of the sound conductor 5 extend, as it does in principle 5 shows. The sound conductor 4 and 5 You can also use a connection type like in 2 with the resonator rod 11 be connected.

In both variants, the sound conductors 4 and 5 only at the front (rear) ends with the resonator rod 11 be connected, as indicated by the solid (dashed) arrows with reference numerals 25 in 6 is shown, or it will be the sound conductors 4 and 5 over welds 25 and / or recesses 13 at each of the front and the rear end of a sound conductor 4 and 5 with the resonator rod 11 connected.

In all embodiments, screening devices with a diameter or length of up to 2650 mm or even 2900 mm or 4000 mm and more can be provided. Such screening devices allow a 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 microns or 1000 microns or finer.

A screening device according to the invention allows a more homogeneous power distribution and a larger power input, which may be locally 10% or 20% or even more.

For connecting the resonator rod 11 with the sound conductors 4 to 6 etc. can be used in addition to, or instead of form-fitting and welding, screwing, gluing, soldering, pressing or other joining method.

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

The excitation frequency is preferably at least one frequency in the range 30 used up to 38 kHz. 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. Among other things, this is due to the fact that a more homogeneous introduction of the vibration power is achieved. It is a more even distribution of energy (ultrasonic energy) achieved and thus arise fewer hotspots, which is very advantageous especially in the explosion-proof field of application.

LIST OF REFERENCE NUMBERS

1

screening

2

Screen area

3

screen frame

4

sound conductor

5

sound conductor

6

sound conductor

7

vibration exciter

8th

mesh

9

Through opening

10

Vibration transmitter

11

resonator rod

12

round bar

13

recess

14

upper part of 11

15

lower part of 4

18

level

19

Level of 9

20

bend

21

bend

22

connecting member

23

connecting member

24

Sound conductor ring

25

Weld

26

execution

27

stabilization

28

Holder of 11

29

admission

30

ultrasonic converter

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 4418175 C5 [0002, 0034]
• DE 102006037638 A1 [0003, 0034]

Claims (24)

Screen device (1) having a screen frame (3) spanning a screen surface (2), at least two sound conductors (4-6) and a vibration exciter (7) to vibrate 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 vibration transmitter (10) comprises a resonator rod (11) to which the two sound conductors (4-6) are coupled. Screen device according to the preceding claim, wherein the resonator rod (11) is solid (or hollow). Sieve device after Claim 1 , wherein the resonator rod (11) is hollow. Screen device according to one of the preceding claims, wherein the resonator rod (11) as a polygonal rod, rectangular rod or round rod (12) is formed, wherein the resonator rod (11) preferably an O, T, X, L, U or V. -shaped cross-section. Screen 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. Screen device according to one of the preceding claims, wherein at least one sound conductor (4-6) is welded or soldered or glued to the resonator rod (11). Screen 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). Screen device according to the preceding claim, wherein the recess (13) is formed in an upper part (14) of the resonator rod (11) and in which a lower part (15) of a sound conductor (4-6) is received in a form-fitting manner, or wherein the recess (13) in a lower part of the Resonatorstabes (11) is formed and and wherein an upper part of a sound conductor (4-6) is accommodated therein. Screen device according to one of the two preceding claims, wherein the resonator rod (11) has two or more recesses (13) for the positive reception of a respective sound conductor (4-6). Screen 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. Screen device according to one of the preceding claims, wherein the resonator rod (11) below the screen frame (3) to the sound conductors (4-6) is guided. Screen 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). Screen device according to the preceding claim, wherein the resonator rod (11) is bent over twice between the screen frame (3) and a first sound conductor (4). Screen device according to one of the preceding claims, wherein at least one sound conductor (4-6) is designed as a closed sound conductor ring (24). Sieve device according to the preceding claim, wherein the sound conductor ring (24) has a rectangular or elliptical shape or a circular shape and / or wherein the sound conductor (4-6) is a polygonal or rectangular or T-, X-, L- or O-shaped or Has U-shaped or elliptical cross-section. Screen device according to one of the preceding claims, wherein at least one sound conductor (4-6) is designed as a hollow profile. Screen 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. Screen device according to one of the preceding claims, wherein the screen frame (3) is covered with a screen fabric (8). Screen device according to the preceding claim, wherein the screen cloth (8) is glued to at least one sound conductor (4-6) and / or the screen frame (3). Screen device according to one of the two preceding claims, wherein the screen fabric (8) comprises two or more layers of fabric. Screen 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. 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 screen surface (2) is mounted. Device according to one of the preceding Claims 1 to 21 , wherein the vibration exciter (7) within the screen surface (2) and preferably above the screen surface (2) is mounted. Device according to one of the preceding claims, wherein at least one second vibration exciter and an associated second resonator rod are provided.

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