Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B07—SEPARATING SOLIDS FROM SOLIDS; SORTING
  • B07B—SEPARATING SOLIDS FROM SOLIDS BY SIEVING, SCREENING, SIFTING OR BY USING GAS CURRENTS; SEPARATING BY OTHER DRY METHODS APPLICABLE TO BULK MATERIAL, e.g. LOOSE ARTICLES FIT TO BE HANDLED LIKE BULK MATERIAL
  • B07B1/00—Sieving, screening, sifting, or sorting solid materials using networks, gratings, grids, or the like
  • B07B1/28—Moving screens not otherwise provided for, e.g. swinging, reciprocating, rocking, tilting or wobbling screens
  • B07B1/34—Moving screens not otherwise provided for, e.g. swinging, reciprocating, rocking, tilting or wobbling screens jigging or moving to-and-fro perpendicularly or approximately perpendiculary to the plane of the screen
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B07—SEPARATING SOLIDS FROM SOLIDS; SORTING
  • B07B—SEPARATING SOLIDS FROM SOLIDS BY SIEVING, SCREENING, SIFTING OR BY USING GAS CURRENTS; SEPARATING BY OTHER DRY METHODS APPLICABLE TO BULK MATERIAL, e.g. LOOSE ARTICLES FIT TO BE HANDLED LIKE BULK MATERIAL
  • B07B1/00—Sieving, screening, sifting, or sorting solid materials using networks, gratings, grids, or the like
  • B07B1/46—Constructional details of screens in general; Cleaning or heating of screens
  • B07B1/4609—Constructional details of screens in general; Cleaning or heating of screens constructional details of screening surfaces or meshes
  • B07B1/4618—Manufacturing of screening surfaces
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B07—SEPARATING SOLIDS FROM SOLIDS; SORTING
  • B07B—SEPARATING SOLIDS FROM SOLIDS BY SIEVING, SCREENING, SIFTING OR BY USING GAS CURRENTS; SEPARATING BY OTHER DRY METHODS APPLICABLE TO BULK MATERIAL, e.g. LOOSE ARTICLES FIT TO BE HANDLED LIKE BULK MATERIAL
  • B07B1/00—Sieving, screening, sifting, or sorting solid materials using networks, gratings, grids, or the like
  • B07B1/46—Constructional details of screens in general; Cleaning or heating of screens
  • B07B1/4609—Constructional details of screens in general; Cleaning or heating of screens constructional details of screening surfaces or meshes
  • B07B1/4663—Multi-layer screening surfaces
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B07—SEPARATING SOLIDS FROM SOLIDS; SORTING
  • B07B—SEPARATING SOLIDS FROM SOLIDS BY SIEVING, SCREENING, SIFTING OR BY USING GAS CURRENTS; SEPARATING BY OTHER DRY METHODS APPLICABLE TO BULK MATERIAL, e.g. LOOSE ARTICLES FIT TO BE HANDLED LIKE BULK MATERIAL
  • B07B2230/00—Specific aspects relating to the whole B07B subclass
  • B07B2230/04—The screen or the screened materials being subjected to ultrasonic vibration

Definitions

• the invention relates to a screening system according to the features of patent claim 1.
• plastic coverings are more elastic, they are not suitable for wear-resistant products.
• the invention has for its object to show a stable as possible and well stimulable screen system, with which it is possible to realize small mesh size with low susceptibility to injury of the wire mesh. At the same time the screen surface should not be reduced as possible. In addition, a weakening the structure of the sieve heat generation should be reduced as far as possible due to an ultrasonic excitation.
• the screening system according to the invention is based on a screen covering and at least one vibration generator coupled to the screen lining.
• screen coating is used in the context of the invention representative of a single-layer or multi-layer structure.
• the Siebbelag consists of one or more layers of screen mesh and is also referred to as Siebgewebe- unit.
• Each screen fabric or layer is formed of metal wires.
• the metal wires of a mesh fabric are firmly bonded together.
• the compound refers to the metal wires of the respective mesh.
• screen surface refers to the area actually available for screening, which is not covered by frame components and other components. However, the invention does not exclude that the areas covered by frame components or other components of the mesh fabric are also bonded together in a material fit.
• the screen mesh is in turn materially connected indirectly or directly to a vibration transmitter, which is equipped with a vibration generator is coupled.
• the vibrator oscillates at a frequency of 30 to 38 kHz.
• "indirectly connected” means that the vibration transmitter itself is connected to the screen fabric via an intermediate component, the so-called vibration transmission surface.
• the vibration transformer is usually a slender, rod-shaped component, the end, ie the mesh fabric, to increase the contact surface with a larger cross-section, z. B. disc-shaped vibration transmitting surface is connected.
• the metal wires are in this invention not only in the edge region, i. H. in the area of the clamping frame, connected to each other, but also within the screen surface. With a connection of the individual metal wires within the screen surface, it is possible to better transfer vibrations that are introduced into the screen fabric from a metal wire to the adjoining metal wire. Ultrasonic vibrations are well forwarded with little energy loss.
• the screen covering becomes inherently more rigid and resistant in both a single ply embodiment and a multi-ply embodiment. There is no friction between the metal wires within a layer and also not between the layers, so that no heat is produced even with ultrasound excitation. This in turn increases the service life of Siebbelags considerably.
• the risk of a wire breakage is significantly lower, since the metal wires are not biased, but form a rigid screen fabric that is sustainable in itself. A tenter is therefore no longer required for such screen fabric.
• the invention does not exclude that in addition an outside frame is provided to allow mounting in existing facilities and adaptation to existing fixtures.
• the mesh fabric is materially connected to a vibration transformer, which in turn with a Vibration generator is coupled. Due to the special nature of the mesh fabric, the vibration transformer can introduce the vibrations directly into the screen mesh. Of course, the invention does not exclude that the screen fabric is additionally added cohesively in a frame to further increase the dimensional stability or to create Abdichtamba. Another vibration transformer can therefore theoretically act on such an outer frame member. The vibration transformer can also be connected, for example, by soldering directly to the mesh.
• the screen mesh is formed by metal wires. These are preferably sintered together.
• sintering means that the metal wires or the screen mesh are heated to temperatures between 1 .100 ° C and 1 .300 ° C.
• the metal wires within a mesh fabric are pressed together under this temperature influence on each other by pressure. They fuse together at their contact points. This process is carried out in particular under vacuum. As a result, each point of intersection of the individual contacting metal wires is formed within a mesh fabric as cohesive connection.
• a mesh or a layer have a mesh size in the order of 20 ⁇ to 5000 ⁇ have, preferably 20 ⁇ to 2000 m, in particular up to 1000 m.
• the thickness of the metal wires is smaller or the same as the respective mesh size.
• the metal wire of the adjacent mesh fabric serves as a support wire against the finer metal wire of the first mesh fabric and has a substantially greater thickness than that of the first mesh fabric.
• the mesh size is much larger. As a result, the size of the screen openings increases in the direction of sieve.
• the difference between the mesh widths of two adjacent screen fabrics is preferably in a range from 1: 2 to 1:20, in particular in a range from 1: 5 to 1:15.
• the second mesh has a mesh size of for example 200 ⁇ . Since the second screen fabric already has a much higher intrinsic stiffness than the first, very fine screen fabric due to the greater thickness of the metal wire, it is not necessary to choose the next increments of the subsequent screen mesh as large as the increment to the first mesh. Therefore, with three or more successive meshes of different mesh sizes, the difference in mesh between a first mesh and a second mesh may be greater than the difference between the second and third mesh. This also applies in the transferring sense to all other screen fabrics.
• a particular challenge is to bond the very thin screen meshes with thick-walled components, in particular with solid frame components. Even a thin-walled sheet metal component does not allow, for example, 20 ⁇ thick metal wires to be welded with these. The thin metal wire of the mesh would melt immediately and would not be there anymore.
• the invention solves this problem by the thicker metal wires of the supporting, further mesh fabrics.
• the thicknesses of the components to be joined together in a material-locking manner resemble each other, so that a process-reliable cohesive joining, in particular welding or soldering or also gluing, is possible.
• the invention further recognizes the fact that the sintered wire mesh laminates can surprisingly be excited very well to vibrate. It has been assumed that the multi-layered wire mesh can not be excited so well to vibrate and that the desired self-cleaning effect or the effect that the friction between the screenings and the mesh is reduced, does not or only insufficiently. However, experiments have shown the opposite. Compared to single-layer, non-sintered wire mesh, the relatively rigid laminate of multiple layers of fabric tends to absorb and transmit the vibrations directly. It comes in a two- or three-layer designed screen covering to an excellent screening performance. Decisive here is the interaction of the vibration excitation, the relatively rigid structure of Siebbelags and the comparatively large screen area.
• An essential advantage of combining a sintered sieve layer with an excitation in the ultrasonic range is that the kinetic energy introduced via the vibration exciter is transmitted over a comparatively large area of the sieve layer and is not dissipated by friction at the contact points of the wires into thermal energy.
• the damping is significantly lower compared to non-sintered Sieblagen. This improves the screening performance.
• the service life of the wire layer is increased, since the introduced kinetic energy is better transferred to the screenings and thus less energy is converted by the screen itself by friction into thermal energy, which adversely affects the stability of the wire layer.
• the possibility of securely fixing a screen covering by means of sintering considerably simplifies the production of the screen covering.
• vibration generators in the ultrasonic range, d. H. at frequencies of 30 to 38 kHz, excellent screening performance can be achieved, but also when the vibrator operates in a range of 30 to 200 Hz, in particular 75 to 120 Hz. These are frequencies that can be generated for example by linear knockers, such. B. a compressed air knocker. It can be used as a vibrator and motors with an imbalance.
• the type of vibration generation is not crucial. Rather, it is crucial that the vibrations can be adjusted as continuously as possible, so that frequency and phase can be changed.
• two vibration generators with different frequencies are provided.
• at least one ultrasonic vibrator should be provided, which operates at 30 kHz to 38 kHz, and on the other hand, at least one further vibration generator, which operates with a so-called ripple frequency of 30 Hz to 200 Hz.
• Linear compressed air knockers that generate frequencies in a range of 75 Hz to 1 15 Hz, for example, can be operated with pressures of 2 bar to 6 bar. By varying the pressure, the frequency is infinitely adjustable.
• the directions of vibration should either be in relation to each other lying parallel planes or in mutually perpendicular planes. Experiments have shown that this can achieve the best sieving results.
• the arrangement of the vibration generator or the arrangement of the exciter to initiate the vibrations in the screen lining are largely dependent on the configuration of the respective screening system. It is considered advantageous if a vibration transmitter surface is arranged between the screen surface and the vibration generator. This leads to the fact that the vibrations can be introduced a little larger area in the screen covering or the screen surface. The local load is slightly reduced, so that the vibrations can be better integrated into the relatively rigid screen mesh, without significantly reducing the screen area.
• a Schwingungsübertrager Structure within the screen surface means that the Schwingungsübertrager Structure is surrounded by the screen surface, the area covered by the Schwingungsschreiber Structure course is no longer permeable to the material to be screened.
• the arrangement and number of Klopfer- or the ultrasonic converter influences the material distribution and movement orientation of the material to be screened.
• the performance of the ultrasonic knocker and the operating pressure of the linear knocker are also decisive here.
• the distributed and trimmed on the particular sintered screen coating stimulators decide on the efficiency of the system.
• Several excitation points with different installation situations and operating points can be mounted on the screen lining.
• the operating point of the vibration generator (ultrasonic converter) is between 30 - 38 kHz with different amplitude and power in a horizontal and / or vertical arrangement.
• the operating point of a linear knocker is 75 - 120 Hz at different working pressures and horizontal and / or vertical arrangement.
• the number of respective stimulators, their installation position and operating points are variable and matched to the material to be screened.
• the invention relates to the additional connection of the metal wires outside these vibrator surfaces. As a result, in particular in the case of sintered screen coverings, all points of contact between adjacent wires are connected to one another in a material-locking manner.
• At least one vibration generator is connected to an exciter frame, which is connected at a distance from the outer edge of the screen surface on one side of the screen surface cohesively with this.
• the at least one excitation frame may be rectangular or substantially rectangular with rounded corners. Square shapes as well as circular shapes are also possible.
• two or more excitation frames arranged separately from one another can also be provided, which in this case have the shape of the letter "D" or of circular segment-shaped frames.
• the exciter frame and its shape have the function to bring the vibration transmitted to him as evenly as possible in the entire screen surface.
• the excitation frame Since the excitation frame is arranged parallel to the screen lining, it has at least one coupling point, which is either oriented parallel to the screen lining or perpendicular to the screen lining.
• the vibrator may alternatively be connected to each of these coupling points, depending on what the screening task requires.
• a plurality of mutually objected Schwingungsübertrager vom can be arranged on the screen surface like an island.
• These vibration transmitter surfaces can be connected via vibration transformers. be coupled. From a single Schwingungsübertrager Structure several vibratory transformers can branch off.
• individual vibration transmission surfaces may be arranged in a star shape around a central vibration transmission surface, the vibration introduction taking place in this middle vibration transmission surface. This serves as a multiplier for the further coupled vibration transmission surfaces.
• further cascaded arrangements may be possible.
• vibration transformers are arranged in such a way that oscillation generator surfaces arranged outside and inside the excitation frame are connected.
• the vibration transformer spans the exciter frame in the distance. Overall, it is considered advantageous if the vibration excitation occurs centrally at least via a vibration generator with substantially circular screen coverings.
• the invention is not limited to circular or semicircular screen coverings.
• the advantageous properties of the invention also result in deviating geometries in the Siebbelastagee, ie polygonal, in particular rectangular or square geometries.
• the properties of the invention arise even when the screen covering is curved, either because it has a wavy or jagged surface or because it is curved concave or convex.
• the invention is therefore not limited to flat screen coverings, but also relates to screen coverings with a curved surface.
• the Siebbelag can z. B. be a portion of a cylinder jacket or a truncated cone.
• the Siebbelag but also a total of z. B. cylindrical or frustoconical.
• the Siebbelag may also be a combination of 3-dimensional geometric shapes, z. B. have a cylindrical or funnel-shaped portion, wherein a front end of the Siebbelags has the shape of a ball cap.
• the material used for the metal wires preferably stainless steel, is corrosion and heat resistant.
• the number of screen meshes to be connected is between 1 and 10.
• the excitation by means of ultrasound can be varied in frequency and phase.
• the direction of movement of the screened material is controlled, inter alia, by different initiation levels of the ultrasound and the low-frequency oscillation.
• the invention has the advantage that a large proportion of the introduced energy acts directly on the screen lining and thus on the screenings.
• the size of the screen surface can be up to 10 square meters, in which case several vibration generators are used.
• Multi-stage cascade screens can each be excited and combined with ultrasound and / or a ripple frequency.
• the invention is particularly suitable for dry screening, for solid and liquid separation, drying, separation, classification, dedusting and filtration.
• FIG. 1 shows a screening system with a view from below of a screen covering
• FIG. 3 shows a screening system in a further embodiment, viewed in the direction of the underside of the screen covering
• Figure 4 shows another embodiment of a screening system with a view of the underside of Siebbelags
• Figure 5 shows another embodiment of a screening system looking towards the underside of Siebbelags and Figure 6 shows a section of the Siebbelags.
• FIG. 1 shows a perspective view of a screening system 1 a with a screen covering 2 and a vibration generator 3, which acts on the screen covering 2 via a vibration transmitting surface 4.
• the Siebbelag 2 is circular.
• the illustrated underside of Siebbelags 2 is flat.
• the actual vibration generator 3 is at a vertical distance from the screen lining 2. It is integrally connected to the vibration transmitter surface 4 via a vibration transmitter 5. The introduction of the vibrations from the vibration generator 3 into the vibration transmitter surface 4 takes place in this orientation of the vibration transmitter 5 perpendicular to the screen lining second
• a second vibration transformer 6, which is angled 90 ° relative to the first-mentioned vibration transformer 5.
• the vibrator 3 may also be coupled to this substantially parallel to the screen lining 2 extending vibration transformer 6, so that the Schwingungsübertrager thoughts 4 initiates vibrations in the Siebbelag 2, which are parallel to the Siebbelag 2.
• the oscillation transfer surface 4 is surrounded at a distance by a square-shaped excitation frame 7, which is formed from hollow profiles and which is materially connected to the screen lining 2.
• the excitation frame 7 has two terminals 8, 9 for receiving a further, not shown vibrator.
• This second vibrator operates at a different frequency than the first vibrator 3. While the first vibrator 3 operates preferably at a frequency of 30 to 38 kHz, the frequency of the second vibrator is in a range of 30 to 200 Hz, in particular in a range of 75 to 120 Hz.
• It may be a linear knocker, for example compressed air operated, which by changing the applied pressure continuously in its frequency is adjustable. It can also be an engine with a flywheel.
• the embodiment of the screening system 16 of FIG. 2 differs from that of FIG. 1 in that, in addition to the central oscillator surface 4, further vibrator surfaces 10 arranged in a star shape around the central oscillator surface 4 are arranged, which however are placed within the exciter frame 7.
• the three additional vibrator surfaces 10 are each offset by 120 °.
• the vibration transmission surfaces 10 are each connected via a single vibration transformer 1 1 with the central vibration transmission surface 4.
• the vibration transformer 1 1 are arranged in a sense as a U-shaped bracket around the central vibration transformer 5 around.
• a further vibration transmitting surface 12, on which a further vibration generator 13 is arranged located within the area bounded by the excitation frame 7, a further vibration transmitting surface 12, on which a further vibration generator 13 is arranged. This also acts in this embodiment perpendicular to the plane 2.
• the frequency of the second oscillator 13 is significantly lower frequency at 30 to 200 Hz than the ultrasonic frequency of the first oscillator 3.
• FIG. 3 shows a further embodiment of a screening system 1 c.
• the central vibration transmitter surface as can be seen in FIGS. 1 and 2, is missing.
• there are two diametrically arranged vibration transmitter surfaces 14, 15 which are located outside the excitation frame 7 and which are each connected to two vibration transmitters 16, 17 are, in turn, configured U-shaped, thereby overlap the mutually opposite longitudinal sides of the exciter frame 7 and are connected to Schwingungsübertrager vom 18 in the interior of the square-shaped exciter frame 7.
• the entire arrangement is mirror-symmetrical.
• vibration transducers 16, 17 is connected to the outer vibration transformer surfaces 14, 15 each have a further vibration transformer 19, 20 which leads radially outward and is used for coupling not shown a vibrator.
• the exciter frame 7 has, as in the embodiment of Figure 1, in turn, two terminals 8, 9, which are arranged at 90 ° to each other and allow the attachment of vibration generators. In the following figures 4 and 5, the representation of these connections is omitted. Nevertheless, the connections can be provided.
• the embodiment of Figure 4 differs from that of Figure 3, characterized in that the local screen 1 d has a central Schwingungsübertrager formula 4 similar to the embodiment of Figure 1, however, in contrast to the embodiment of Figure 2, 4 instead of 3 further Schwingungsübertrager inhabit 10th within the excitation frame 7 has.
• the Schwingungsübertrager inhabit 10 are located substantially in the corner of the exciter frame 7, without being connected to these. Also missing in this embodiment, the possibility of the central Schwingungsübertrager schizophrenia
• the sieve system 1 e of Figure 5 differs from that of Figure 4 only in that the exciter frame 7 in its outer dimensions has been made smaller, whereas the again star-shaped vibration transmitting surfaces 10 are not within the exciter frame 7 in this embodiment, but outside of the excitation frame 7.
• the vibration transformer 1 1 are designed to be longer and extend through the corner regions of the exciter frame. 7
• FIG. 6 shows the structure of a sieve cloth unit 21, of which the sieve lining 2 consists.
• the screen mesh unit 21 is formed as a sintered laminate.
• the screen fabric unit 21 and, accordingly, the screen cover 2 are multi-layered in this embodiment.
• the Siebgewebe- unit 21 as well as the other components of the screen system made of metal, in particular stainless steel.
• the sieve cloth unit 21 has two different sieve cloths 22, 23.
• the lower sieve cloth 22, which is lower in the image plane, is the narrower sieve cloth. It faces the screenings.
• This close-meshed mesh 22 is supported by a second mesh 23.
• the metal wires 24 in the second screen fabric 23 are considerably thicker, more dimensionally stable and connected by total sintering with the first screen fabric 22.

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• Engineering & Computer Science (AREA)
• Manufacturing & Machinery (AREA)
• Combined Means For Separation Of Solids (AREA)

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Citations (5)

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• 2012
  • 2012-04-11 DE DE102012103084A patent/DE102012103084B3/de active Active
• 2013
  • 2013-04-11 WO PCT/DE2013/100138 patent/WO2013152765A1/fr not_active Ceased

Patent Citations (5)

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