EP4000752A1 - Screening tool and screening device - Google Patents

Abstract

The screening tool (10) comprises a screen covering which is connected to at least one coupling element (16) which can be connected to an ultrasonic generator (3) via an ultrasonic transducer (2). According to the invention, a metal worktop (11) is provided with an upper side and an underside, which has at least one connection area (118) to which the at least one coupling element (16), which is rod-shaped and made of metal, is welded, and the at least a transfer area (119) with first transfer openings (110), which forms a first screen cloth.

Description

The invention relates to a screening tool for processing a process item using ultrasound and a screening device having at least one such screening tool.

Screening devices, which are used to divide a process material, e.g. a mixture of solids, into fractions with different grain sizes, are used, for example, in the processing of raw materials, the food industry, the chemical industry and the building materials industry.

According to https://en.wikipedia.org/wiki/Sieve , a screening device comprises a screen lining which, as the separating medium, contains a large number of openings of the same size. The screen lining consists either of metal (perforated sheet metal, wire mesh, metal grid or metal rods), plastic, rubber of various hardnesses or silk gauze. The size of the openings is referred to as the mesh size and defines the sieve cut. Larger grains remain above the openings (sieve overflow), smaller grains fall down (sieve passage). A grain that is roughly the same size as the mesh size is called the limit grain. A screen can consist of one or more screen decks one on top of the other, with the screen deck with the largest mesh width being on top of the stack of screens. The cleanliness of the screen lining is important for the efficiency of a screen. In particular, the blockage of the screen openings by marginal grain must be prevented by suitable measures (e.g. brushes, balls, chains, rubber blocks that "run" on or under the screen or by increasing the hole diameter downwards, such as with conical or double-cylindrical holes , be avoided).

the WO2018219840A1 discloses a screening device with a screening tool that has a screen frame by which a screen cloth is held. To improve the screening performance, ultrasonic energy is coupled into the screen frame, which is distributed from the screen frame to the screen lining.

This arrangement has significant disadvantages. The screen lining is normally firmly connected, welded or glued to the screen frame and, if defects occur, can only be replaced with great effort, i.e. together with the entire screen frame.

The peripheral coupling of ultrasonic energy results in an uneven distribution of the ultrasonic energy on the screen cloth and often an undesirable heating of the screen cloth or parts thereof, which can lead to significant mechanical and thermal loads. Due to the peripheral coupling of the ultrasonic energy, temperatures occur in the coupling zone of the screen cloth and in the central area of the screen cloth on its elements, which differ significantly from one another and can cause high mechanical stresses. The selective occurrence of high temperatures can lead to damage to the screen lining, its periphery or its working area, e.g. at connection points or on individual wires of the wire mesh.

In addition to thermal material damage from melting, further material damage can occur due to mechanical stress. Mechanical stresses can cause parts of the screen lining or wire mesh to tear open, which is why the screen tool has to be replaced, which involves a corresponding amount of effort.

It is also important that an impermissibly high heating of the process material can occur at certain points. Pharmaceutical powders or foodstuffs in powder form can be structurally altered by heating and lose the required properties. On the other hand, partial damage may mean that the entire processed process item can no longer be used.

It should also be noted that known screening tools can only be used in a narrow area of application. In order to fulfill different screening functions, several screening tools are usually required.

It should be noted that screening tools are not only used for conventional screening, but also for other purposes will. For example, media are fed through the screen mesh to a processed product.

It is therefore an object of the present invention to provide an improved screening tool that operates using ultrasonic energy and a screening device having such a screening tool.

The screening device should allow a product or process material to be efficiently processed, screened or mixed or metered or changed under the influence of other media.

If possible, the screening device should cause little or no maintenance. If maintenance of the screening device is required, this should be able to be carried out quickly with little effort, so that only low maintenance costs and downtimes for the screening device result.

Furthermore, the screening device should be able to be adapted to changed work processes quickly and with minimal effort.

The screening tool is intended to ensure efficient processing of the process material, so that the process material or processed product can be optimally screened or mixed or dosed or changed in some other way.

When screening process material, an increased material throughput should be achieved. Furthermore, it should be possible to precisely mix or dose process material, even in very small quantities. If a different processing of the process item is planned, particles of the process item should be reliably isolated and processed, e.g. loaded with other media.

The screening tool should ensure optimal transmission of ultrasonic energy to the screen lining and the process material. Here, thermal and mechanical overloading of the screening tool or parts thereof should be avoided as well impermissible heating of the process material or the processed product.

The screening tool should work largely maintenance-free. On the other hand, if maintenance, possibly replacement of a screen lining, should become necessary, the maintenance work should be able to be carried out quickly and with minimal effort.

With a single screening tool, it should also be possible to support different work processes at the same time, e.g. to carry out more than one screening process at the same time.

This object is achieved with a screening tool and a screening device which have the features specified in claims 1 and 11, respectively. Advantageous configurations of the invention are specified in further claims.

The screening tool, which is used to process a process material, includes a screen covering that is connected to at least one coupling element that can be connected to an ultrasonic generator via an ultrasonic transducer. The process material is, for example, a food product, a chemical product, or a pharmaceutical product that is wholly or partially passed through the screen mat. Typically, the process material is supplied as a powder, granulate or in a mixed form.

According to the invention, a metal worktop is provided with an upper side and an underside, which comprises at least one connection area, to which the at least one coupling element, which is rod-shaped and made of metal, is welded, and which comprises at least one transfer area with first transfer openings, the one forms the first screen lining.

The screening tool thus includes a worktop with a one-piece integrated screen covering into which ultrasonic energy can be coupled directly. Between the welded-on coupling element or the welded-on coupling elements and the screen cloth or all of them There are therefore no further transitions between elements of the screen cloth, such as pinch points, weld points, adhesive points provided peripherally on the screen cloth, and soft points, which must overcome the inflowing ultrasonic energy and which usually absorb ultrasonic energy and heat up.

There are therefore no energy losses at transitions, which would require greater coupling of ultrasonic energy, which in turn leads to increased energy losses and increased heating. Since energy losses are avoided, the screening tool according to the invention works with increased efficiency and requires less ultrasonic energy, as a result of which losses and heating that occur at the welding point of the coupling element are reduced even further. The welding point is therefore less stressed.

Since there is no increased heating of the screen cloth and, in particular, selectively increased heating or so-called hotspots within or on the periphery of the screen cloth, temperature expansions within the screen cloth, which could lead to mechanical damage to the screening tool or parts thereof, are also avoided. Screening tools according to the invention can therefore be operated in a largely wear-free and maintenance-free manner.

Since there is no increased heating of the screen lining and selectively increased heating in it, there are also no disadvantageous effects on the processed process material.

Since heating and hotspots in the screening tool are largely avoided when coupling in ultrasonic energy, the screening tool also allows the coupling of increased ultrasonic energy in order to process the process material, which cannot be processed or cannot be processed efficiently with conventional screening tools. The screening tool according to the invention can therefore be operated, if necessary, with small amounts of energy or also with very high amounts of energy, and thus has high dynamics.

When processing, in particular screening of process material, due to the high efficiency of the screening tool, an increased throughput of Achieved process material, which is fed to the screening tool during the machining process and removed from it again. The process material does not necessarily have to be guided through the screen lining. Instead, a medium that is used to process the process material can be guided through the screen lining. For example, the process item is kept isolated above the screen covering under the action of ultrasonic energy, while a medium is guided through the screen covering of the screening tool, by means of which the isolated particles of the process item are acted upon. For example, air, gas, moisture, steam or a powdery process material is supplied through the first screening tool or another screening tool. During processing, the particles of the process item are coated, for example, and/or their structure is changed and/or compacted and/or coupled with other particles of the process item or the supplied powder.

The use of the correspondingly stable worktop also allows the screening tool to be advantageously coupled to at least one additional tool or tool unit, by means of which the process material can be pre-processed or post-processed. For example, a tool unit is provided, by means of which the process material can be conveyed and/or mixed and/or separated and/or swirled and/or mixed or acted upon with another material component.

The tool unit can have moving parts and/or non-moving parts. A drive motor is preferably provided, by means of which moving parts can be driven. For example, at least one rotor is provided on one side of the working plate of the screening tool, by means of which supplied process material can be separated and/or swirled and/or guided or pressed against the working plate. On the other side, a rotor can again be provided, by means of which the process material guided through the screen lining is swirled, so that it can be discharged in an evenly distributed manner.

PREFERABLY, the worktop has at least one mounting element, by means of which the at least one additional tool unit can be held. The stable worktop serves on the one hand as a screen surface and on the other hand as a base plate for connecting other tools.

In a preferred embodiment, the worktop includes an opening or bearing opening in which a rotor shaft is guided and preferably mounted or, for example, held by means of a bearing bush, so that at least one rotor above the worktop and/or at least one rotor below the worktop can be driven by means of the rotor shaft.

The dimensions of the screening tool and the structure of the screen lining can be adapted to the processes and process materials at hand. In the field of pharmacy, for example, very small quantities of a process item can be processed using screening tools with correspondingly small dimensions, for example with screen surfaces in the range of only 1 cm ² . In the food industry, screen decks with surfaces in the range of several square meters can be used. The worktop has, for example, a thickness in a range of 0.5 mm - 20 mm, more preferably in a range of 1 mm - 5 mm and a surface in a range of 1 cm2 - 16 m2.

In preferred configurations, the coupling element or the worktop is curved in its connection area or in the transfer area. The coupling element and the connection area are preferably curved. In this way, an optimal coupling of ultrasonic energy into the transfer area of the worktop is achieved. The transfer area can also have a surface waviness which, with a correspondingly selected frequency of the ultrasonic energy and with a given particle size of the process material, results in improved work results, in particular optimum separation of the particles of the process material.

The worktop and the at least one coupling element are preferably made from the same material. High-quality metals such as stainless steel, chromium steel, aluminium, copper or titanium are preferably used for the production of the screening tool.

In preferred configurations, it is provided that at least one second screen mat is arranged on the upper side of the worktop and/or on the underside of the worktop. For example, a second, third or additional screen covering in the form of a wire mesh or a perforated plate is placed on the worktop. Typically, the transfer openings, mesh openings or hole openings of this at least one second screen mat are selected to be smaller than the transfer openings of the worktop. Second and further screen decks made of metal are particularly preferred. On the other hand, screen linings made of plastic can also be used.

Numerous advantages result from the use of an additional screen mesh. The second or second and further screen deck is structurally supported by the worktop and therefore need not have any inherent stability. The screen linings can therefore be manufactured in a simple manner and with a minimum of effort. Wire meshes with thin wires or thin metal plates or foils can be used, for example, which can be manufactured or processed in a simple manner, e.g. by means of stamping technology, etching technology or laser technology. The screen linings can be manufactured at low cost and ideally adapted to the user's processes.

Second or additional screen decks can be attached to the screen tool as required and replaced in just a few simple steps. Adaptation to process changes is possible without replacing the screening tool and only by replacing the second or additional screen lining. The screening tool can thus be quickly adapted to any process.

As a result, ultrasonic energy is not only peripheral, but over the entire surface of the second or subsequent screen cloth evenly coupled into it. There is no heating and no hotspots within the additional screen linings. Due to the optimal coupling of ultrasonic energy over the entire surface of the screen mat, the result is optimal work results and only minimal strain on the screen mats. Due to the optimal coupling of ultrasonic energy, the coupled ultrasonic energy can in turn be reduced. If, on the other hand, a coupling of ultrasonic energy is desired, there is no heating and no damage to the screen lining due to the optimal coupling.

The coupling of a flexible screen covering to the worktop is preferably carried out by assembly elements and is supported by the process material placed in the work area. Furthermore, an atmospheric overpressure can be provided on one side, by means of which the at least one second screen surface is pressed or pulled against the worktop.

Mounting elements are preferably provided, by means of which the at least one second screen mat is pressed against the worktop and possibly tensioned. The assembly elements can be connected to the screening tool in a positive or non-positive manner or can be connected during the process of assembling the screening tool in the screening device.

The worktop preferably has one or more recesses on at least one side, in which or in which the at least one second screen surface or the assembly elements are held. The screening tool can therefore also be designed flat and thin with the equipment of further screen linings and can be advantageously used in any processes.

The at least one second screen lining is preferably held by a mounting frame made of metal or plastic. The mounting frame is connected to the worktop with other mounting elements such as metal or plastic screws or pneumatic elements such as inflatable tires. Preferably, a mounting frame made of plastic, which is fixed with plastic screws. The mounting frame can have any geometric shape, for example it can be round or rectangular.

The use of pneumatic elements allows the screening tool to be installed and removed again in a simple manner, for example in order to place a new, second or additional screen surface.

In preferred configurations, at least one encircling embossed or molded shaped element, such as an encircling groove or an encircling ring, is provided on the upper side and/or on the underside of the worktop. Corresponding to this shaped element, the at least one second screen cloth has a shaped or stamped counter element. The positive connection of the form element and the counter element ensures that the second or further screen deck is automatically installed correctly.

In preferred configurations, it is provided that the second screen cloth and at least one third screen cloth are preferably of identical design and are shifted relative to one another in such a way that a combined screen cloth results. In this way, by shifting the second and third screen decks, a combined screen deck can be created with transfer openings, the dimensions of which are defined by the mutual shifting of the screen decks.

In preferred embodiments, the second screen mat can also be displaced relative to the worktop to create a worktop with a combined screen mat.

In further preferred configurations it is provided that the worktop comprises a plurality of transfer areas with transfer openings. The transfer areas can have different dimensions and/or the transfer openings can have different dimensions, it being possible for transfer areas of any size to be provided with transfer openings of any size. the Individual transfer areas are preferably separated from one another on the upper side and/or the lower side of the separating plate by walls, possibly walls of containers or pipes. A pipe or a container can also be assigned to each transfer area. Several processes can therefore be operated with just one screening tool. Each transfer area can be used separately from the other transfer areas within a work process.

A dividing wall, a transfer pipe or a container can be connected to the transfer area or to one or more transfer areas on the underside and/or the top of the worktop. For example, a transfer tube is connected to one of the transfer areas on the upper side of the separating plate and a container is provided on its underside, which receives the processed process material.

In preferred configurations, the connection area of the screening tool is inclined in relation to the transfer area. The screening tool can therefore be designed as desired and adapted to the infrastructure of the system that is provided for the work process. The connection area can be part of a wall, such as a partition wall or a container wall.

The screening device can have one or more screening tools, each of which is connected to an ultrasonic generator via at least one coupling element and an ultrasonic transducer. The individual ultrasonic converters can preferably be controlled individually, so that the screening tools and parts thereof can be individually adapted to each process stage.

Fig. 1

eine für verschiedene Arbeitsprozesse einsetzbare erfindungsgemässe Siebvorrichtung 1 mit einem Siebwerkzeug 10, das eine Arbeitsplatte 11 aufweist, die einen Transferbereich 119 mit ersten Transferöffnungen 110 und zwei Anschlussbereiche 118 umfasst, in denen gekrümmt verlaufende Kopplungselemente 16 angeschweisst sind, denen von einem Ultraschallgenerator 3 über je einen Ultraschallwandler 2 Ultraschallenergie zuführbar ist;

Fig. 2

das Siebwerkzeug 10 von Fig. 1 in Explosionsdarstellung mit der Arbeitsplatte 11, die innerhalb des Transferbereichs 119 mit den ersten Transferöffnungen 110 einen ersten Siebbelag bildet, mit einem zweiten Siebbelag 12 und einem dritten Siebbelag 13, die mittels eines Montagerahmens 18 auf der Arbeitsplatte 11 fixierbar sind;

Fig. 3

in Explosionsdarstellung ein Siebwerkzeug 10 mit der Arbeitsplatte 11 von Fig. 2, an der in dieser Ausgestaltung an der Unterseite der zweite Siebbelag 12 und an der Oberseite der dritte Siebbelag 13 mittels je eines Montagerahmens 18 fixierbar ist;

Fig. 4a

ein erfindungsgemässes Siebwerkzeug 10, das nur einen mit einem Kopplungselement 16 verschweissten Anschlussbereich 118 aufweist und das mittels pneumatischen Elementen 51, 52 montierbar ist;

Fig. 4b

einen Teil der Arbeitsplatte 11 von Fig. 4a mit ersten Transferöffnungen 110;

Fig. 4c

das Siebwerkzeug 10 von Fig. 4a in Explosionsdarstellung;

Fig. 5

ein Siebwerkzeug 10 gemäss Fig. 4a in einer vorzugsweisen Ausgestaltung mit einer Arbeitsplatte 11 mit mehreren Transferbereichen 119A, 119B, 119C und 119D, die erste Transferöffnungen 110A, 110B, 110C, 110D mit unterschiedlichen Abmessungen aufweisen;

Fig. 6

zwei Siebwerkzeuge 10 gemäss Fig. 4a, die kombiniert miteinander ein zweistufiges Siebwerkzeug 100 bilden;

Fig. 7

ein Siebwerkzeug 10 mit einem Anschlussbereich 118 und einem Transferbereich 119, die gegeneinander geneigt sind, und einer anschliessenden Wand 116, wie einer der Wand eines Rohrs oder Behälters;

Fig. 8a

eine Siebvorrichtung 1 mit einem Siebwerkzeug 10, das mit einer Werkzeugeinheit 19 verbunden ist, die der Vorbearbeitung eines zugeführten Prozessmaterials dient, und die einen Rotor oder Propeller 191 umfasst, der von einer Rotorwelle 192 oberhalb des Transferbereichs 119 der Arbeitsplatte 11 gehalten ist;

Fig. 8b

einen Teil der Siebvorrichtung 1 von Fig. 8a mit der vorzugsweise ausgestalteten Werkzeugeinheit 19, die einen Rotor 191A oberhalb und zwei Rotoren 191B, 191C unterhalb des Transferbereichs 119 der Arbeitsplatte 11 hält; und

Fig. 8c

die Siebvorrichtung 1 von Fig. 8a mit einer Fördervorrichtung 9, mittels der Prozessmaterial zuführbar und wegführbar ist.

The invention is explained in more detail below with reference to drawings. It shows:

1

a screening device 1 according to the invention that can be used for various work processes, with a screening tool 10 that has a worktop 11, which comprises a transfer area 119 with first transfer openings 110 and two connection areas 118, in which curved coupling elements 16 are welded, to which ultrasonic energy can be supplied by an ultrasonic generator 3 via an ultrasonic transducer 2 each;

2

the sieve tool 10 of 1 in an exploded view with the worktop 11, which forms a first screen mat within the transfer area 119 with the first transfer openings 110, with a second screen mat 12 and a third screen mat 13, which can be fixed on the worktop 11 by means of a mounting frame 18;

3

in an exploded view a screening tool 10 with the worktop 11 of 2 , on which, in this embodiment, the second screen mat 12 can be fixed on the underside and the third screen mat 13 can be fixed on the top by means of a respective mounting frame 18;

Figure 4a

a screening tool 10 according to the invention, which has only one connection area 118 welded to a coupling element 16 and which can be assembled by means of pneumatic elements 51, 52;

Figure 4b

a part of the countertop 11 of Figure 4a with first transfer openings 110;

Figure 4c

the sieve tool 10 of Figure 4a in exploded view;

figure 5

a screening tool 10 according to Figure 4a in a preferred embodiment with a worktop 11 with a plurality of transfer areas 119A, 119B, 119C and 119D, which have first transfer openings 110A, 110B, 110C, 110D with different dimensions;

6

two screening tools 10 according to Figure 4a , which combine to form a two-stage screening tool 100;

7

a screening tool 10 having a connection portion 118 and a transfer portion 119 inclined towards each other and an adjoining wall 116 such as one of the wall of a pipe or container;

Figure 8a

a sifting device 1 with a sifting tool 10 connected to a tool unit 19 for pre-processing a supplied process material and comprising a rotor or propeller 191 supported by a rotor shaft 192 above the transfer area 119 of the working plate 11;

Figure 8b

a part of the screening device 1 of Figure 8a with the preferably configured tool unit 19 holding one rotor 191A above and two rotors 191B, 191C below the transfer area 119 of the worktop 11; and

Figure 8c

the screening device 1 of Figure 8a with a conveyor device 9, by means of which the process material can be fed in and taken away.

1 1 shows a screening device 1 according to the invention with a mounting structure 100 by means of which a screening tool 10 is held or a plurality of screening tools 10 arranged in series or parallel to one another are held. If several screening tools 10 are present, they can have the same or different screen linings. The screening device 1 can be used to carry out a number of processes for processing a material to be screened 61 in process stages which are arranged in parallel or in series with one another. The screening tool 10 is held or connected to the assembly device 100 by means of assembly elements 51 , 52 . The assembly device 100 and the assembly elements 51, 52 are shown schematically by dot-dash lines. As mounting elements 51, 52 are preferably provided brackets made of plastic. In a preferred embodiment, at least one pneumatic element, such as an expandable or inflatable tube or tire, is provided, by means of which the screening tool 10 can be fixed to the assembly device 100 . By means of a pneumatic element 51, the screening tool 10 can be pushed against the assembly device 100, for example from above. Alternatively, two pneumatic elements 51, 52 are held by the assembly device 100, as is shown in Figure 4a is shown as an example. By inflating the pneumatic elements 51, 52, preferably controllable by means of a control unit 8, the screening tool 10 can be fixed and released again. The screening tool 10 can therefore be easily replaced within a few seconds. This solution can also be used for conventional screening tools that have a mounting frame with a screen lining. In this case, the assembly frame can be fixed by means of the pneumatic elements 51, 52.

1 shows the sieve tool 10 or one of the sieve tools 10, which has a worktop 11 with two connection areas 118 and a transfer area 119 lying between them. Bent or curved, rod-shaped coupling elements 16 made of metal are welded to the connection areas 118, to each of which an ultrasonic transducer 2 is connected. Piezoelectric elements are preferably provided in the ultrasonic transducers 2 and are rigidly connected to the coupling elements 16 . An ultrasonic generator 3 supplies the ultrasonic transducers 2 via connecting lines 31 and 32 with an alternating voltage in the ultrasonic range, which is converted by the piezo elements of the ultrasonic transducers 2 into mechanical vibrations that are transmitted to the coupling elements 16 . Due to the curved coupling elements 16, the ultrasonic energy is optimally coupled into the worktop 11 and can be distributed evenly within the one-piece worktop 11.

By coupling ultrasonic energy optionally via two coupling elements 16, mechanical vibrations of correspondingly high amplitude can be transmitted to the worktop without it is thermally or mechanically overloaded. Furthermore, the mechanical vibrations can be switched on or off individually or their frequency and amplitude can be changed.

The ultrasonic generator 3 is controlled by a control unit 8 via a control line 81 . By appropriately controlling the ultrasonic generator 3, electrical AC voltage signals in the subsonic range with a selected frequency and amplitude can be transmitted, preferably selectively, via the lines 31, 32 to the connected ultrasonic transducers 2.

The frequency of the signals emitted by the ultrasonic generator 3 can be keyed in order to avoid standing waves within the worktop 11. The different effects of ultrasonic energy from both sides of the worktop 11 via the coupling elements 16 can also act on the process material 61 in order to move it and preferably distribute it evenly. At least one sensor 7 , for example a camera, is preferably provided for monitoring the work process and preferably also the process item 61 , the signals of which are transmitted to the control unit 8 via the measuring line 82 . The control unit 8 can therefore control the delivery of ultrasonic energy to the two coupling elements 16 based on the evaluation of the sensor signals.

A process for dosing process material can also be carried out by means of the control unit 8 . For example, the transfer openings 110, 120, 130 of a screen covering 11, 12, 13 are filled with process material within a period in which no ultrasonic energy is injected. Subsequently, ultrasonic energy is applied and the transfer ports 110, 120, 130 are evacuated.

The process item 61 can be processed in various ways. For example, the process material 61 is passed through the screening tool 11 and is screened and delivered to a receiving container 4 or to a conveyor belt 40 . The processed process item 62 can also be further processing stages. The process material 61 can also be processed above the screening tool 10 with the supply of media 71, 72 without being guided through the worktop 11. Instead, at least one medium 71 such as air, gas or steam can be guided through the worktop 11 in order to treat or act on the process item 61 or the isolated particles of the process item 61 . For example, air 71 at a certain temperature is guided through the worktop 11 in order to swirl it, and steam or mist 72 is blown in from above in order to act on the particles of the process material 61 . The processed process item 62 can then be removed above the worktop 11 .

In the embodiment shown, the worktop 11 is optionally provided with a second screen covering 12 which has second transfer openings 120 . The first screen covering of the worktop 11, which is formed by the transfer area 119 and the first transfer openings 110, is therefore hardly visible.

The second screen mat 12 is held peripherally by a mounting frame 18 which is connected to the worktop 11 by means of mounting screws 181 . The second screen mat 12 is only intended to be held and pressed against the worktops 11 by means of the mounting frame 18, which is why the mounting frame 18 and the mounting screws 181 are preferably made of plastic and therefore do not absorb any ultrasonic energy.

2 shows the screening tool 10 of FIG 1 in an exploded view with the one-piece worktop 11. The rectangular transfer area 119 lying between the connection areas 118 has ten rows of holes, each with ten transfer openings 110, and is slightly sunk into the worktop 11.

The worktop 11 or the transfer area 119 together with the transfer openings 110 forms the first screen covering, which alone can be sufficient for the processing of a process item 61 . He can do that Transfer area 119 can be provided with any number of transfer openings 110 with dimensions selected as required. The transfer openings 110 are preferably arranged equidistantly on a correspondingly provided area. Depending on the user's needs, this surface can be regular or irregular and can include, for example, a number of wings, circles, rectangles or the like in order to form any desired screen surface. The worktop 11 is preferably adapted to the infrastructure of a process plant, for example to pipes or ducts, and can also have any regular or irregular shape and can be rectangular or circular, for example.

The transfer openings 110 can be incorporated into the worktop 11 in any desired manner, e.g. If the worktop 11 is chosen to be relatively thin in the transfer area 119, openings are preferably punched in or inserted by laser beams.

As 1 shows, arbitrarily designed coupling elements 16 can be connected to the connection areas 118 of the worktop. 7 shows that the connection area or areas 118 can be inclined relative to the transfer area 119 . For example, the connection area 118 can be connected to a partition wall, such as a wall of a pipe or container 116, in a modular manner or in one piece.

Ultrasonic energy coupled onto the worktop 11 via the coupling elements 16 spreads practically without losses over the entire transfer area 119, which forms a first screen covering. If the worktop 11 and the transfer area 119 with the transfer openings 110 are adapted to the work process, the process item 61 can be optimally processed with minimal ultrasonic energy. Due to the direct and uniform distribution of the ultrasonic energy, there is no heating and no hotspots on the worktop 11 which could stress the screen covering or the process material 61 .

The screening tool 10 with the worktop 11 can therefore be operated with maximum efficiency and without any signs of wear.

As 2 shows, the transfer area 119 can optionally be covered with a second screen surface 12 or further screen surfaces, for example a third screen surface 13 . In most applications, the support of only a second screen cloth 12 will suffice.

The support of at least one second screen surface 12 is associated with various significant advantages that have already been described above. Like this in 2 is shown, the other screen linings 12, 13 can be made very thin and are therefore particularly easy to manufacture. The screen linings 12, 13 can be easily installed and also quickly and easily replaced again.

Since the ultrasonic energy is distributed evenly over the entire worktop 11, there is also an even transmission of the ultrasonic energy to the additional screen decks 12, 13 placed thereon pressed, so that an optimal and even coupling of ultrasonic energy takes place in this area as well. The other screen linings 12, 13 are therefore protected not only mechanically by the adjacent worktop 11, but also thermally against undesirable effects. The worktop 11 also acts as a heat sink if the screen linings 12, 13 that are placed on it should heat up. The worktop 11 therefore also ensures optimal operation of the additional screen mesh 12 or the additional screen meshes 12, 13.

As mentioned, the transfer area 119 is preferably slightly sunken and surrounded by a peripheral mounting channel or a peripheral indentation 111 which serves to accommodate the mounting frame 18 .

Inside the mounting channel 111 is a circumferential shaped element 112, in this embodiment a circumferential groove, provided, in which a correspondingly shaped counter element 122; 132 can be inserted, which is provided on at least one second screen cloth. Several shaped elements 112 or part of shaped elements 112 can also be provided, which allow the second screen mesh 12 to be displaced relative to the worktop 11 or which allow the second and third screen mesh 12, 13 to be displaced relative to one another.

In the design of 2 the second screen cloth 12 and the third screen cloth 13 comprise second and third transfer openings 120, 130, respectively, which have different dimensions. Identical second and third or further screen decks 12, 13 can also be provided, which can be shifted relative to one another, if necessary, in order to close the transfer openings 120, 130 as required.

3 shows an exploded view of a screening tool 10 with the worktop 11 of 2 , At which in this embodiment on the underside of the second screen cloth 12 of 2 and at the top of the third screen cloth 13 of 2 can be fixed by means of a mounting frame 18 each. The worktop 11 can therefore be used without additional screen panels 12, 13 or can optionally be provided with identical or different screen panels 12, 13 of any number on the underside and the top.

Figure 4a 12 shows a screening tool 10 according to the invention, which has only one connection area 118 welded to a coupling element 16 and which can be assembled by means of pneumatic elements 51, 52. The transfer area 119 adjoining the connection area 118 has a circular shape and is held between the two tire-shaped pneumatic elements 51, 52 which, for example, belong to the infrastructure of a plant. To remove the screening tool 10, the pneumatic elements 51, 52 are evacuated. To fix the screening tool 10, the pneumatic elements 51, 52 are inflated again. At the same time, the mounting ring 18 shown can be pressed against the worktop 11 to at least one to fix the screen lining 12 placed on it. The screen mat 12 can therefore be replaced within minutes to accommodate a process change.

Figure 4b shows part of the worktop 11 of FIG Figure 4a with first transfer openings 110 and with the second screen cloth 12, which is designed as a mesh.

Figure 4c shows the screening tool 10 of FIG Figure 4a in exploded view. The second screen mat 12 is arranged on the upper side of the worktop 11 this time.

figure 5 shows a screening tool 10 according to FIG Figure 4a in a preferred embodiment with a worktop 11 with a plurality of transfer areas 119A, 119B, 119C and 119D, which have first transfer openings 110A, 110B, 110C, 110D with different dimensions. The individual transfer areas 119A, 119B, 119C and 119D are separated from one another by partitions 151, 152, so that different screening processes can be carried out with the same screening tool 10 in four quadrants. The screening processes can be independent of one another or alternatively follow one another. The transfer areas 119A, 119B, 119C and 119D can also be arranged on differently configured surfaces, for example rectangular or circular surfaces, so that pipes or containers with a corresponding cross-section can be connected.

6 shows two screening tools 10 according to FIG Figure 4a , which combine to form a two-stage screening tool 100 . Instead, two or more screening tools could also be used in accordance with 1 or figure 5 combined and mechanically coupled. In the case of the lower screening tool 10, the transfer area 119 is lower than the connection area 118, so that a second screen lining 12 can be inserted in a simple manner.

Figure 8a shows a screening device 1 with a screening tool 10 which is connected to a tool unit 19 that is preferably provided is used for the pre-processing of a supplied process material. The screening tool 10 is held by a holder 92 and partially surrounded by a retaining ring 921 . Above the transfer area 119 is a cup-shaped inlet channel 91 shown in a sectional representation, which encloses the transfer area 119 and into which a process material is introduced or several different process materials are introduced. A portion of the entry channel 91 has been cut away to reveal the screening tool 10.

Below the transfer area 119, a funnel-shaped outlet channel 93 adjoins the worktop 11, a quarter of which has also been cut away. Process material can therefore be fed to the screening tool 10 through the inlet channel 91 and removed through the outlet channel 93 .

A rotor shaft 192 , which is driven by a drive motor 193 and which drives a rotor 191 with two rotor blades 1911 , is guided through the worktop 11 in the transfer area 119 . When the rotor 191 rotates, the supplied process material is evenly distributed above the transfer area 119 and, if necessary, pressed against the worktop 11 .

The worktop 11 can therefore advantageously be used to hold at least part of the tool unit 19, which is why the sieve tool 10 and the tool unit 19 can advantageously be combined and/or connected to one another.

A vibrator 14 which causes mechanical vibrations is additionally connected to the holder 92 . Mechanical vibrations of the vibrator 14 , ultrasonic waves supplied via the ultrasonic transducer 2 and the coupling element 16 and, if appropriate, mechanical forces of the rotor 191 thus act on the screening tool 10 .

Figure 8b shows part of the screening device 1 of FIG Figure 8a with the preferably configured tool unit 19 with a rotor shaft 192 supporting one rotor 191A above and two rotors 191B, 191C below the transfer area 119 of the worktop 11. The rotor shaft 192 is held in a bearing bush 199 which is inserted into a bearing opening 1190 provided in the center of the transfer region 119 of the worktop 11 bearing opening 1190 . The two rotors 191B, 191C below the worktop 11 can work in the same direction or in opposite directions, so that, for example, process material is sucked in and/or swirled, as is symbolically represented by two arrows.

Furthermore, it is possible to arrange separate tool units 19 below and above the worktop 11 . The worktop 11 therefore serves not only as a tool plate, but also as a base plate for the assembly of additional tool units 19. A simple and compact construction of the screening tool and additional tool units 19 is thus possible.

Figure 8c shows the screening device 1 arranged on a frame 90 from FIG Figure 8a with a conveyor device 9, by means of which the process material can be fed in and taken away.

The conveyor device 9 comprises the input channel 91 and the output channel 93 as well as a transport device 94 which is held in suspension below the output channel 93 by elastic cables 95 . The transport device 94 is designed as a transport frame or conveyor channel with an upwardly open V-profile.

The transport frame 94 is connected to an ultrasonic generator 3 via distribution plates 161, preferably curved, rod-shaped coupling elements 16 and ultrasonic transducers 2, by means of which ultrasonic energy can be transmitted to the metal transport frame 94.

The ultrasonic generator 3 from 1 and Figure 8c generates electrical alternating voltage signals in the ultrasonic range from, for example, 25 kHz to 45 kHz. The AC voltage signals are supplied in the ultrasonic transducer 2, for example, piezoelectric elements, for example, by a coupling rod are firmly connected to the coupling rod 16 . The electrical AC voltage signals are converted into mechanical vibrations by the piezo elements and transmitted to the transport frame 94 via the coupling rod 16 and the distribution plate 161 .

The distribution plate 161 can be welded to the transport frame 94 or, as in Figure 8c shown to be integrally connected.

By being coupled in via the coupling rod 16 and the distribution plate 161 , the ultrasonic energy is not coupled into the transport frame 94 at specific points, but rather along the connection side of the distribution plate 161 . Problems that result from the conventional point-by-point coupling of ultrasonic energy, such as overheating and material stresses that could destroy the connection point, are avoided. The ultrasonic energy is coupled into the transport frame 94 over a larger area, which is why, on the one hand, coupling losses are reduced and, on the other hand, an optimal distribution and effect of the ultrasonic energy in the transport frame 94 is achieved. The shown one-piece connection of the distribution plates 161 to the transport frame 94 is particularly advantageous. Overall, the manufacturing effort is reduced since the transport frame 94 and the distribution plate 161 can be manufactured in one work step. Welding on the distribution plates 161 is no longer necessary. There are also no contact resistances and material stresses at the welded connection points. Furthermore, there are no thermal loads on the connection points, since the thermal energy can be distributed more quickly, so that optimal operating conditions are always present. Likewise, the distribution plates 161 avoid disadvantageous repercussions from the process material on the ultrasonic device, in particular the ultrasonic transducer 2, which could occur when the coupling rods 16 are connected at certain points. If the process material has a temperature in the range of 200°, for example, a significant cooling takes place via the distribution plates 161 and thus a reduced heat effect on the ultrasonic transducer 2.

The transport frame 94 is kept practically floating by the elastic ropes 95 . An outflow of coupled ultrasonic energy via assembly elements is avoided. The ultrasonic energy can be distributed evenly over the transport frame 94 and develop an optimal effect. The process material can advantageously be distributed and slide downwards without friction over the inclined transport frame 94 . Conveying speed of the process material can be controlled by controlling the application of ultrasonic energy so that metered dispensing can occur.

Claims (15)

Screening tool (10) for processing a process material with a screen covering which is connected to at least one coupling element (16) which can be connected to an ultrasonic generator (3) via an ultrasonic transducer (2), characterized in that one having an upper side and a lower side provided metal worktop (11) is provided, the at least one connection area (118) to which the at least one coupling element (16), which is rod-shaped and made of metal, is welded, and the at least one transfer area (119) with first transfer openings (110) which forms a first screen cloth through which the process material or parts thereof can pass. Sieving tool (10) according to Claim 1, characterized in that the worktop (11) has at least one mounting element (1190), by means of which at least one motorized or non-motorized tool unit (19) is used for additional processing, such as conveying, mixing, or separation, the process material is used, can be combined or connected with the screening tool (10). Sieve tool (10) according to Claim 1 or 2, characterized in that the tool unit (19) comprises a rotor shaft (192) which is rotatably held in a mounting element designed as a bearing opening (1190) perpendicularly or inclined to the worktop (11) and the other at least one rotor (191A, 191B, 191C) on the top or bottom of the worktop (11) or on the top and bottom of the worktop (11). Sieving tool (10) according to any one of claims 1-3, characterized in that on the top of the worktop (11) or on the underside of the worktop (11) at least a second screen lining (12; 13), such as a wire mesh or a perforated plate, or that at least one second screen mat (12; 13) rests on the top and bottom of the worktop (11), the at least one second screen mat (12; 13) being provided with second or further transfer openings (120; 130). is, which are smaller than the first transfer openings (110) of the worktop (11). Screening tool (10) according to Claim 4, characterized in that the at least one second screen lining (12, 13) is pressed or clamped onto the worktop (11) by means of assembly elements (18, 181; 51, 52) or that the worktop (11) has one or more recesses (111, 112) on at least one side, in which or in which the at least one second screen cloth (12, 13) or the assembly elements (18, 181) are held. Sieve tool (10) according to Claim 4 or 5, characterized in that a mounting frame (18) made of metal or plastic is provided which can be attached by means of further mounting elements (181; 51, 52), such as screws (181) made of metal or plastic or pneumatic elements (51, 52), such as inflatable hoses or tires, is connected to the worktop (11) and presses the at least one second screen mat (12, 13) onto the worktop (11). Sieving tool (10) according to one of Claims 1 - 6, characterized in that the worktop (11) has at least one embossed or molded shaped element (112) on the top or bottom, such as a circumferential groove or a circumferential ring, on which shaped element (112) a corresponding formed or stamped counter element (122; 132) is held, which is provided on at least one second screen cloth (12, 13). Screening tool (10) according to one of Claims 1 - 7, characterized in that the second screen cloth (12) and at least one third screen cloth (13) are preferably of identical design and are shifted relative to one another in such a way that a combined screen cloth results or that the second screen cloth (12) and at least one third screen cloth (13) have second and third transfer openings (120; 130) with different dimensions. Screening tool (10) according to one of Claims 1 - 8, characterized in that the worktop (11) comprises a plurality of transfer areas (119A, 119, 119C, 119D) with transfer openings (110A, 110, 110C, 110D), the transfer areas (119A , 119B, 119C, 119D) or transfer openings (110A, 110, 110C, 110D) have the same or different dimensions and that the transfer areas (119A, 119B, 119C, 119D) are preferably separated from one another by walls or tubes (151, 152). Sieving tool (10) according to one of Claims 1 - 9, characterized in that the connection area (118) is inclined relative to the transfer area (119) and optionally adjoins a wall (116) such as a partition wall or container wall. Sieving device (1) with an ultrasonic generator (3) which is connected on the one hand to a control unit (8) via control lines (81) and which on the other hand is connected to at least one ultrasonic transducer (2) by an output line (31), and having a mounting structure ( 70), of which at least one screening tool (10) according to one of Claims 1 - 10 is held, which has a metal worktop (11) which has at least one connection area (118) with a coupling element (16) which is connected to the at least one ultrasonic transducer (2) and which comprises at least one transfer area (119) with first transfer openings (110) forming a first screen cloth. Screening device (1) according to claim 11, characterized in that on the top of the worktop (11) or on the underside of the worktop (11) at least a second screen mat (12; 13), such as a wire mesh or a perforated plate, or at least one second screen mat (12; 13) rests on the top and bottom of the worktop (11), the at least one second screen mat (12; 13 ) is provided with second or further transfer openings (120; 130) which are smaller than the first transfer openings (110) of the worktop (11). Screening device (1) according to Claim 11 or 12, characterized in that the worktop (11) comprises a plurality of transfer areas (119A, 119, 119C, 119D) with transfer openings (110A, 110, 110C, 110D), the transfer areas (119A, 119B , 119C, 119D) or transfer openings (110A, 110, 110C, 110D) have the same or different dimensions and that the transfer areas (119A, 119B, 119C, 119D) are preferably separated from one another by walls or tubes (151, 152). Sieving tool (10) according to Claim 11, 12 or 13, characterized in that on the transfer area (119) or on one or more of the transfer areas (119A, 119B, 119C, 119D) on the underside and/or the upper side of the worktop ( 11) a transfer tube (116), a container (116), or a partition (116) made of metal or plastic. Screening device (1) according to one of Claims 11 - 14, characterized in that a pneumatically actuatable mounting element (51, 52), such as a hose or a tire, is provided, by means of which the screening tool (10) can be fixed on the mounting structure (70). or that two pneumatically actuable mounting elements (51, 52), such as a hose or a tire, are provided, by means of which the screening tool (10) can be fixed to the mounting structure (70).

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