Discharging device for bulk material

Abstract

The invention relates to a discharging device (1) for compressing and discharging, in a discharging direction (2), bulk material of limited pourability, comprising a conveying channel (5) formed by a housing (4), wherein the housing (4) has a first flat wall (8) and a second flat wall (9) situated opposite the first flat wall (8), wherein the flat walls (8, 9) have a respective angle of inclination (11, 12) relative to the discharging direction (2) such that the conveying channel (5) tapers in the discharging direction (2). Also provided are a first friction disk (13), which is closest to the first flat wall (8) inside the conveying channel (5), is rotatable about a first axis of rotation (15) and has a first friction surface (14) facing away from the first flat wall (8), and a second friction disk (16), which is closest to the second flat wall (9) inside the conveying channel (5), is rotatable about a second axis of rotation (18) and has a second friction surface (17) facing away from the second flat wall (9), wherein the friction disks (13, 16) are drivably coupled to at least a first drive motor (19) such that, when the friction disks (13, 16) are driven, material for grinding, or bulk material, can be compressed by means of the friction surfaces (14, 17) and discharged in the discharging direction (2). The invention also relates to a method for determining the bridging of bulk material.

Description

[0001] DISCHARGE DEVICE FOR BULK MATERIAL

[0002] The invention relates to a discharge device for compressing and discharging non-free-flowing ground material or fine-granular and possibly only partially free-flowing bulk material.

[0003] In the plastics industry and plastics processing, it may be necessary to add regrind or bulk material to a process or material stream, which regrind or bulk material can ideally also be pre-compacted. For example, regrind or bulk material can be compressed or pre-compacted from a storage container using a discharge device, then discharged and added in appropriate quantities to the material stream of an extruder or to material streams in other process steps of plastics production.

[0004] EP1637824 B1 and EP3628611 A1 disclose devices for discharging and dosing ground material or bulk material. A device comprising a rotary valve or a rotary valve is used as the discharge device. Particularly with non-free-flowing ground material or fine-granular and only partially free-flowing bulk material, which can be used as additives in plastics production or processing, this can lead to jamming of the material, the occurrence of material agglomerations, or undefined material or bulk material densities due to the inherent compression of the bulk material in certain areas, which has a detrimental effect on process reliability and accuracy in plastics production or processing.

[0005] The object of the present invention was to overcome the disadvantages of the prior art and to provide a discharge device by means of which material agglomerations can be avoided in a simple manner and ground material or partially free-flowing bulk material can be compressed and discharged, so that the process reliability and accuracy in plastics production or processing are improved.

[0006] This object is achieved by a discharge device according to the claims. The discharge device according to the invention for compressing and discharging non-free-flowing or poorly free-flowing ground material or fine-granular and / or partially free-flowing bulk material in a discharge direction from a storage orSilo, comprises a conveyor channel formed in sections by a housing with an inlet area and a discharge area, wherein the housing has a first flat wall and a second flat wall opposite the first flat wall along a normal direction relative to the discharge direction, wherein the first flat wall has a first angle of inclination relative to the discharge direction from a range comprising -1° to -60°, in particular -5° to -45°, and the second flat wall has a second angle of inclination relative to the discharge direction from a range comprising 1° to 60°, in particular 5° to 45°, so that the conveyor channel is designed to taper in the discharge direction.

[0007] Furthermore, a first friction disc, in particular a circular one, is provided or formed, which is closest to the first planar wall within the conveying channel and is rotatably mounted, and has a first friction surface facing away from the first planar wall. A second friction disc, in particular a circular one, is provided or formed, which is closest to the second planar wall within the conveying channel and is rotatably mounted, and has a second friction surface facing away from the second planar wall. The first friction surface is aligned substantially parallel to the first planar wall, and the second friction surface is aligned substantially parallel to the second planar wall.The first friction disc is rotatable about a first axis of rotation oriented substantially normally relative to the first flat wall, and the second friction disc is rotatable about a second axis of rotation oriented substantially normally relative to the second flat wall, wherein the first friction disc and the second friction disc are drivable or rotationally drivable coupled to at least one first drive motor, so that when the first friction disc and the second friction disc are driven by means of the at least one first drive motor and thus by rotating the first friction disc and the second friction disc, ground material or bulk material can be compressed by means of the friction surfaces of the friction discs and can be discharged in the discharge direction.

[0008] The flat and preferably circular design of the respective friction surface and the corresponding dimensioning of the friction surfaces and the conveyor channel promote the formation of bridges between the particles of the bulk material, so that the bulk material is compressed by the rotational energy of the friction discs introduced via friction on the friction surfaces in interaction with the tapered conveyor channel and is discharged from the discharge device in order to be able to make the bulk material available in compressed form for a further process. The simple design of the discharge device according to the invention largely prevents any regional agglomeration of the bulk material and thus areas with undefined orundesirably increased density is avoided, so that according to the rotation speed of the friction discs in conjunction with the design of the conveyor channel depending on the properties of the bulk material, a process-reliable and process-precise discharge of the bulk material is guaranteed in terms of dosing of the bulk material.

[0009] Another advantageous embodiment is one in which the first friction disc is drivably coupled to the at least one first drive motor, and the second friction disc is drivably coupled to a second drive motor. This allows the rotational movement of the first friction disc and the second friction disc to be individually regulated or controlled. This allows the dosing or compression of the bulk material to be regulated or controlled as needed.

[0010] According to a further development, it is possible for a drive shaft penetrating the first flat wall and the second flat wall along the normal direction to be formed with a drive rotation axis, wherein the drive shaft is rotatably coupled to the at least one first drive motor, and wherein the first friction disc and the second friction disc are each rotatably coupled or rotationally connected to the drive shaft and are each pivotably mounted relative to the drive rotation axis, wherein the first friction disc is pivotally operatively coupled to the first flat wall and the second friction disc is pivotally operatively coupled to the second flat wall.The friction discs are thus pivotally coupled to their nearest flat wall, since the pivoting movement of the friction discs relative to the drive axis of rotation is initiated by the friction discs bearing against the nearest flat wall or by interposing a coupling element when the friction discs rotate. Thus, the friction discs rotating during operation of the discharge device are always aligned essentially parallel to the nearest walls. The pivot point of the friction discs essentially results from the intersection of the respective axis of rotation of the friction disc and the drive axis of rotation. In other words, the friction discs perform a pivoting movement relative to the drive axis when they rotate.

[0011] During operation, the discharge device is necessarily positioned adjacent to a storage or silo for bulk material in the discharge direction, with the discharge direction preferably running vertically, so that the bulk material sinks from the storage into the discharge device due to the force of gravity acting on it. Due to the conveyor channel tapering from the inlet area to the discharge area and the rotation of the round friction surfaces of the friction discs, the bulk material is compacted or compressed in the sections of the round friction surfaces that are moved essentially counter to the discharge direction in accordance with the rotation of the friction discs.On the other hand, the bulk material is conveyed to the discharge area in the sections of the round friction surfaces, which are moved essentially along the discharge direction according to the rotation of the friction discs. The material is thus discharged from the discharge device in a compressed state, in order to feed it to a further, subsequent process. The dual effectiveness of the round friction surfaces for section-by-section compression and discharge of the bulk material prevents any agglomeration or jamming of the bulk material in certain areas.Furthermore, a particularly wide range of applications for the discharge device with regard to bulk materials with a wide variety of properties is possible thanks to an appropriate fill level of bulk material in the storage unit upstream of the discharge device, the inclination angles of the flat walls matched to the properties of the bulk material, and the rotation speed and design of the round friction surfaces of the friction discs coordinated with one another. Furthermore, the discharge speed and the degree of compression of the bulk material can be easily implemented by appropriately controlling the rotation of the friction discs, for example, by increasing the rotation speed or reversing the direction of rotation, using the discharge device according to the invention, or even undesirable agglomeration in the conveyor channel can be easily resolved using control technology.These advantages, among other things, significantly improve process reliability and accuracy in plastics production and processing compared to state-of-the-art discharge devices.

[0012] Furthermore, it may be expedient for the first friction disc and the second friction disc to be mounted on the drive shaft by means of a ball flange, each with its own ball socket, and for them to be drivably coupled to the drive shaft by means of a driver element in operative connection with a starting element for transmitting torque. As an alternative to the ball flange in conjunction with a driver element in combination with a starting element, a torque-transmitting connection with simultaneous pivoting of the friction discs could also be designed as a splined shaft, a curved-tooth coupling, or a simple tongue-and-groove connection with corresponding degrees of freedom for the pivoting movement of the friction discs.In any case, the proposed connection ensures that torque can be transmitted from the drive shaft to the friction discs, with the friction discs still being pivotally mounted relative to the drive shaft's axis of rotation, so that the friction discs are always aligned essentially parallel to the nearest flat wall. Thus, the tapered shape of the conveyor channel is also maintained by the position of the friction discs, and the bulk material can be compressed and discharged accordingly.

[0013] Furthermore, a roller or plain bearing device can be provided or formed between a flat wall and a friction disc located closest to it. This simply prevents the friction discs from hitting the nearest flat wall, and the friction discs are mounted axially with respect to their respective axes of rotation. This minimizes the torque required to rotate the friction discs, which, on the one hand, leads to improved efficiency of the discharge device and, on the other hand, improves the synchronization of the rotation of the friction discs, thus enabling targeted compression and discharge of the bulk material.

[0014] Furthermore, it can be provided that the respective roller or plain bearing device is designed as a thrust ring and, with the associated friction disc, as a sliding pair, with the respective thrust ring being made of the softer material of the sliding pair. This results in a firm contact of the friction discs on the respective thrust ring, which improves the smooth running of the friction discs rotating during operation of the discharge device and, in turn, enables targeted compression and discharge of the bulk material.

[0015] According to a special embodiment, it is possible for the respective roller or plain bearing device to have a radial opening running in a circumferential direction of the roller or plain bearing device in a section closest to the discharge area, so that any bulk material that undesirably penetrates into the space between the respective friction disc and the nearest flat wall can be discharged. Bulk material can, under certain circumstances, penetrate into the space that is necessarily present between a friction disc and the nearest flat wall due to the provision of a gap to prevent the friction disc from starting or due to the provision of a roller or plain bearing device. This can affect the smooth running of the friction discs rotating during operation and can subsequently also lead to increased wear. By providing openings, any bulk material that undesirably penetrates into this space can be discharged.This further improves the efficiency and process reliability of the discharge device. Alternatively, or in addition to this, slots or grooves can be provided in the flat walls, preferably extending along the discharge direction, to facilitate the removal of bulk material from the space between the friction disc and the nearest flat wall.

[0016] Furthermore, it may be expedient for the housing to have a deflector plate in the inlet area, each fixed in position on the first flat wall and the second flat wall, wherein the first friction disc and the second friction disc are partially covered by the respective deflector plate in the discharge direction. The deflector plates can preferably cover the entire broad side of the friction discs in a projection onto the floor plan of the discharge device. Furthermore, the deflector plates can preferably be designed such that they have a shape that follows the curved shape of the friction discs, whereby the respective friction disc is completely covered by the respective deflector plate in the discharge direction. This largely prevents bulk material from penetrating the space between the friction disc and the nearest flat wall.Thus, the effectiveness and process reliability of the discharge device are once again improved, as already described above.

[0017] Furthermore, it can be provided that the first flat wall and the second flat wall have openings in a respective overlap area of ​​the first friction disc and the second friction disc, respectively, i.e., leading into the respective space between the friction disc and the respective nearest flat wall. The openings are pneumatically coupled to a gas supply device for introducing gas at an overpressure relative to the ambient pressure. This allows, on the one hand, sealing air to be introduced into the space between the respective friction disc and the nearest flat wall to better prevent unwanted penetration of bulk material.On the other hand, process-relevant gas, such as dry air, can also be pumped into the conveyor channel to dry bulk material, trigger chemical reactions between the introduced gas and the bulk material, or simply purge the space between the respective friction disc and the nearest flat wall. Furthermore, this design allows unwanted agglomerations to be broken up by introducing purge air.

[0018] Another advantageous embodiment is one in which at least one further friction disc, which is rotatably coupled to the drive shaft and is in particular circular and has opposing friction surfaces, is provided between the first friction disc and the second friction disc, wherein the friction surfaces are aligned normal to the drive axis of rotation. For the compression and discharge of the bulk material, bridging of the bulk material between two nearest friction surfaces is necessary. Depending on the properties of the bulk material, the maximum possible distance between two nearest friction surfaces that still allows bridging of the bulk material can vary. If the conveyor channel is designed for a high throughput of bulk material, it may happen that the distance in the normal direction between the first friction surface and the second friction surface is too large for sufficient bridging of the bulk material.By providing the additional friction wheel, this circumstance can be counteracted and a high throughput or a high discharge rate of bulk material can be achieved with the discharge device, while at the same time the bridging of the bulk material for compression and process-reliable discharge of the bulk material can still be achieved.

[0019] According to a further development, the friction discs can have several cavities distributed across the respective friction surface, starting from the respective friction surface. Cavities include, for example, recesses, bores, blind holes, conical counterbores, slots, grooves, or grooves, which cavities can be positively connected to the bulk material. This can improve the compression and discharge of bulk material, since the positive effect of the cavities increases the rotational energy that can be introduced into the bulk material by means of the friction discs and via the friction surfaces compared to a design of the friction discs without cavities.

[0020] Furthermore, it can be expedient if a scraping element extending between two or respectively between two friction discs is formed in a fixed position on the housing, so that entrainment of ground material or bulk material can be prevented when the discharge device is driven or when the friction discs are rotating in the opposite direction to the discharge direction. The scraping element or the respective scraping element can extend between two nearest friction discs or span or bridge the distance between two nearest friction discs. The scraping element or the respective scraping element can extend from the housing in the direction of the conveyor channel and preferably also in the direction of the inlet area. The scraping element or the respective scraping element can be designed as a sheet metal element or a sheet metal element curved in the direction of or in the direction opposite to the discharge direction.This prevents the friction discs from transporting bulk material in the opposite direction to the discharge direction. With a suitably curved design of a scraper element, the compression of the bulk material, or the movement of the bulk material within the conveyor channel caused by the rotation of the friction discs, can also be controlled. This allows a defined compression of the bulk material to be easily adjusted.

[0021] Furthermore, it can be provided that the scraping element or the respective scraping element is designed as a metal sheet bridging the distance in the normal direction between two friction disks, wherein the scraping element or the respective scraping element has an angle relative to the discharge direction from a range comprising 5° to 90°, in particular 10° to 60°. In this case, the scraping element or the respective scraping element can also only have an angle relative to the discharge direction from a range comprising 5° to 90°, in particular 10° to 60°, in only sections. The scraping element or the respective scraping element can furthermore be designed to protrude or project from the housing up to the position of the respective axis of rotation of the friction disks or up to the position of the drive axis of rotation, wherein the scraping element is designed to be positionally fixed on that side of the housing so that by means of the scraping element orof the respective scraping element, the entrainment of ground material or bulk material can be prevented when the discharge device is driven or when the friction discs are rotating in the opposite direction to the discharge direction.

[0022] The provision and the previously described design of the scraping element or the respective scraping element not only prevent the entrainment of ground material or bulk material when the driven discharge device or the respective rotating friction discs are in the opposite direction to the discharge direction, but the bulk material is also compressed by conveying it in the direction of the scraping element or the respective scraping element by means of the rotating friction discs. It is important to ensure that a gap is provided between the scraping element or between the respective scraping element and the nearest friction disc to prevent the friction discs from contacting the scraping element.

[0023] The invention further relates to a method for quantifying or determining the bridging of bulk material, the method comprising the following method steps:

[0024] - Providing a discharge device comprising

[0025] - - a conveying channel formed by a housing, wherein the housing has a first wall and a second wall opposite the first wall, wherein the walls each have an angle of inclination relative to the discharge direction, so that the conveying channel is tapered in the discharge direction,

[0026] - - a first friction disc, which is closest to the first flat wall within the conveying channel and is rotatable about a first axis of rotation and has a first friction surface facing away from the first flat wall,

[0027] - - a second friction disc, which is closest to the second flat wall within the conveying channel and is rotatable about a second axis of rotation and has a second friction surface facing away from the second flat wall,

[0028] - wherein the first friction disc is drivably coupled to a first drive motor and the second friction disc is drivably coupled to a second drive motor, and

[0029] - - a control or regulating device coupled to the first drive motor and the second drive motor; and

[0030] - Filling the conveyor channel (5) with bulk material;

[0031] The method is further characterized in that the first drive motor drives the first friction disc with a predefined first torque and a predefined first speed in accordance with a specification of the control or regulating device, wherein the second drive motor is not driven and a second torque and a second speed transmitted at the second drive motor by the second friction disc and via the bridging of the bulk material within the conveying channel from the first friction disc are measured and / or recorded by means of the control or regulating device, such that a reference value for the bridging of the bulk material is determined by means of the control or regulating device. The advantage of the present method is that the bridging of the bulk material can be easily quantified.This makes it possible to directly determine the material properties of the bulk material using the discharge device, which can then be used to adjust the operating or process parameters when using the discharge device to compress and discharge the bulk material. This provides the advantage of enabling quick and easy resumption of operation using the discharge device when changing the bulk material or when using a bulk material with previously unknown material properties.

[0032] For a better understanding of the invention, it is explained in more detail using the following figures.

[0033] They show in a highly simplified, schematic representation:

[0034] Fig. 1 is an elevational view of a possible first embodiment of the discharge device;

[0035] Fig. 2 is an elevational view of a possible second embodiment of the discharge device;

[0036] Fig. 3 shows a further elevation of a section of a possible third embodiment of the discharge device.

[0037] By way of introduction, it should be noted that in the variously described embodiments, identical parts are provided with identical reference symbols or component designations. The disclosures contained throughout the description can be applied analogously to identical parts with identical reference symbols or component designations. Furthermore, the positional information chosen in the description, such as top, bottom, side, etc., refers to the directly described and illustrated figure, and these positional information must be applied analogously to the new position in the event of a change in position.

[0038] Fig. 1 shows an elevation of a possible first embodiment of the discharge device 1 in a schematic and highly simplified representation, wherein the discharge device 1 is provided for compressing and discharging non-free-flowing or difficult-to-flow ground material or fine-granular and / or partially free-flowing bulk material in a discharge direction 2 from a storage unit or silo 3. The discharge device 1 can have a conveying channel 5, formed at least in sections by a housing 4, with an inlet area 6 and a discharge area 7. The housing 4 can have a first flat wall 8 and a second flat wall 9, wherein the second flat wall 8 can be arranged opposite the first flat wall 9 in a normal direction 10 relative to the discharge direction 2.Furthermore, the first flat wall 8 can have a first angle of inclination 11 relative to the discharge direction 2 from a range comprising -1° to -60°, in particular -5° to -45°, and the second flat wall 9 can have a second angle of inclination 12 relative to the discharge direction 2 from a range comprising 1° to 60°, in particular 5° to 45°, so that the conveying channel 5, which is formed in sections by the first flat wall 8 and the second flat wall 9, can be designed to taper in the discharge direction 2.

[0039] The discharge device 1 can further comprise a first friction disc 13, which is preferably circular and positioned within the conveying channel 5 and closest to the first planar wall 8. The first friction disc 13 can be rotatably mounted or rotatable relative to the housing 4 and have a first friction surface 14, which first friction surface 14 faces away from the first planar wall 8 and thus faces the conveying channel 5. The first, preferably circular, friction disc 13 is rotatable about a first axis of rotation 15.

[0040] The discharge device 1 can further comprise a second friction disc 16, which is preferably circular and positioned within the conveying channel 5 and closest to the second flat wall 9. The second friction disc 16 can be rotatably mounted or rotatable relative to the housing 4 and have a second friction surface 17, which second friction surface 17 faces away from the first, second wall 9 and thus faces the conveying channel 5. The second, preferably circular, friction disc 16 is rotatable about a second axis of rotation 18.

[0041] The first rotation axis 15 is preferably aligned perpendicular to the first flat wall 8, and the second rotation axis 18 is preferably aligned perpendicular to the second flat wall 9. The thus rotatable first friction disc 13 can thus have a substantially identical inclination to the first flat wall 8. The thus rotatable second friction disc 16 can have a substantially identical inclination to the second flat wall 9.

[0042] The first friction disc 13 and the second friction disc 16 can be coupled in a drivable or rotationally drivable manner by means of at least one first drive motor 19, so that the friction discs 13 and 16 rotate during operation of the discharge device 1, or a torque provided by the at least one first drive motor 19 is transmitted, so that the friction discs 13 and 16 rotate. However, it can also be provided that the first friction disc 13 is coupled in a drivable or rotationally drivable manner by means of the at least one first drive motor 19, and the second friction disc 16 is coupled in a drivable or rotationally drivable manner by means of a second drive motor 20.

[0043] The discharge device 1 can preferably be positioned and oriented such that the discharge direction 2 runs in the vertical direction. As a result, when the discharge device 1 is in operation, bulk material contained in the silo 3 can push into the discharge device 1 or sink therein due to gravity. If the friction discs 13 and 16 are driven so that they rotate, the bulk material is compressed by the friction discs 13 and 16 and discharged in the discharge direction 2. The conveying channel 5 can be designed such that the bulk material to be conveyed has a bridge formation between the friction discs 13 and 16 caused by the internal friction of the particles of the bulk material. This improves the compression of the bulk material. It can also be provided that the first drive motor 19 and the second drive motor 20 are controlled orThe control device can be controlled in such a way that jams or agglomerations in the bulk material can be loosened or resolved by corresponding rotational movements of the drive motors 19, 20 or by the associated interaction of the friction discs 13, 16 with the bulk material. For example, it is conceivable that the rotation directions of the drive motors 19, 20 are offset and run in opposite directions in order to resolve jams.

[0044] Furthermore, it can also be conceivably advantageous if the discharge device 1 comprises further friction discs (not shown), which further friction discs can be arranged below the friction discs 13, 16 in the discharge direction 2. This can improve the bridging of the bulk material or, after prior compression by means of the friction discs 13, 16, the bulk material can be loosened by means of the further friction discs. This way, the bulk material can be compressed and conveyed in the discharge direction 2, while at the same time the flowability of the bulk material is restored or improved by means of the further friction discs. By arranging the further friction discs, even flatter angles of inclination 11, 12 can be achieved, for example, since the bulk material can be compacted by means of the friction discs 13, 16 as well as by means of the further friction discs.This can naturally be continued in discharge direction 2 with a large number of additional friction discs.

[0045] As an alternative embodiment, it is also conceivable for the friction discs 13, 16 to be positioned or arranged in recesses or niches (not shown) in the flat walls 8, 9. This can, for example, easily prevent bulk material from accumulating between the flat walls 8, 9 and the friction discs 13, 16. This also prevents abrupt deflection of the bulk material in the transition area between the flat walls 8, 9 and the friction discs 13, 16.

[0046] In any case, the previously mentioned control or regulating device can be designed to control the drive motors 19 and 20 in such a way that the compression and the conveying quantity of the bulk material can be adjusted by means of the rotational speed of the friction discs 13, 16.

[0047] A further method for determining the bridging of the bulk material can be carried out by means of the control or regulating device. For example, the first drive motor 19 can drive the first friction disk 13 with a predefined first torque and a predefined first speed, wherein the second drive motor 20 is not driven and a second torque and a second speed transmitted from the second friction disk 16 and via the bridging of the bulk material by the first friction disk 13 are measured on the second drive motor 20. In this way, conclusions can be drawn about the bridging of the bulk material between the first friction disk 13 and the second friction disk 16. As a result, a reference value for the bridging of the bulk material can be determined by means of the control or regulating device in order to subsequently adjust or adapt the compression and the conveying rate of the bulk material during operation of the discharge device 1.

[0048] Fig. 2 shows an elevation of a possible second and possibly independent embodiment of the discharge device 1, wherein the same reference numerals or component designations as in the previous Fig. 1 are used for the same parts. To avoid unnecessary repetition, reference is made to the previous description. The discharge device 1 shown in Fig. 2 can again have a housing 4 with a first flat wall 8 and a second flat wall 9, which in turn can have a first angle of inclination 11 and a second angle of inclination 12, respectively, as described above. Furthermore, the discharge device again has a first friction disk 13 and a second friction disk 16.

[0049] In contrast to the possible first embodiment of the discharge device 1, the discharge device 1, as shown in Fig. 2, can have a drive shaft 21 with a drive rotation axis 22, wherein the drive shaft 21 can be coupled to the drive motor 19 in a rotationally movable or torque-transmitting manner. Furthermore, the first friction disc 13 and the second friction disc 16 can each be rotatably coupled or rotatably connected to the drive shaft 21, wherein the first friction disc 13 and the second friction disc 16 are each coupled to the drive shaft 21 or mounted thereon in such a way that the friction discs 13, 16 are pivotable relative to the drive axis of rotation 22, so that the friction discs 13, 16 are always aligned at least approximately parallel to their nearest flat wall 8 or 9, wherein the friction discs 13, 16 are still rotatable about their axes of rotation 15, 18 and preferably follow the rotational movement of the drive shaft 21 without slippage.Thus, the friction discs 13, 16 are pivotally and operatively coupled to their respective nearest flat wall 8 or 9, since the pivoting movement of the friction discs 13, 16 relative to the drive axis of rotation 22 is initiated by the friction discs 13, 16 correspondingly abutting against the respective nearest flat wall 8 or 9 or by interposing a coupling element, such as a roller or plain bearing device 23, upon rotation of the friction discs 13, 16.

[0050] In order to ensure this pivoting movement of the friction discs 13, 16 relative to the drive axis of rotation 22 with simultaneous torque transmission by means of the drive shaft 21, a friction disc 13 or 16 can be pivotally mounted with the drive shaft 21 by means of a ball flange 24 and associated ball socket of the respective friction disc 13 or 16, wherein a torque can also be transmitted from the drive shaft 21 to the respective friction disc 13, 16 by means of a driver member 26 in operative connection with a starting element 27. Conceivable embodiments of this operative connection for transmitting torque with simultaneous pivotability of the friction discs 13 or 16 are, for example, a splined shaft with a corresponding counter profile, a curved-tooth coupling (s-connection) or a simple torque transmission by means of a pairing of a groove and an associated starting flank.

[0051] As already mentioned above, a roller or plain bearing device 23 can be provided between the respective friction disc 13 or 16 and the flat wall 8 or 9 closest thereto. In particular, the roller or plain bearing device 23 can be formed by a thrust ring 28, wherein the thrust ring 28 forms a sliding pair with the respective associated friction disc 13 or 16, wherein the respective thrust ring 28 can be designed as a replaceable wearing part and can thus be formed from the softer material of the sliding pair. Alternatively, however, it can also be provided that the roller or plain bearing device 23 is designed as an axial roller bearing, wherein the respective friction disc 13, 16 rolls on the axial roller bearing assigned to it.

[0052] The roller or plain bearing device 23 can have, in a section closest to the discharge area 7, a radial opening 30 extending in the circumferential direction of the roller or plain bearing device 23, so that unwanted bulk material penetrating from the space between the friction disk 13 or 16 and the nearest flat wall 8 or 9 can be removed.

[0053] In order to prevent this unwanted penetration of bulk material into the space between the friction disk 13 or 16 and the nearest flat wall 8 or 9 as far as possible, the housing 4 can have a deflector plate 29 in the inlet area 6, which is fixed in position on the first flat wall 8 and the second flat wall 9, wherein the first friction disk 13 and the second friction disk 16 are partially covered by the respective deflector plate 29 in the discharge direction 2. It can be provided that the respective deflector plate 29 has a shape that follows the preferably circular shape of the friction disks 13 16, so that complete shielding of the friction disks 13 16 in the discharge direction 2 or, with a corresponding arrangement of the discharge device 1, in the vertical direction is ensured. Alternatively or additionally, as previously explained, it can be provided that the friction discs 13 16 and accordingly also the respective roller orPlain bearing device 23 is positioned in a recess or niche of the respective flat walls 8, 9.

[0054] In order to prevent the penetration of bulk material into the space between friction disc 13 or 16 and the nearest flat wall 8 or 9 as far as possible, it can further be provided that the first flat wall 8 and the second flat wall 9 have openings 31 in a respective overlap area with the first friction disc 13 or with the second friction disc 16, wherein the openings 31 can be pneumatically coupled to a gas supply device for introducing gas at an overpressure relative to the ambient pressure. In this way, the space between friction disc 13 or 16 and the nearest flat wall 8 or 9, i.e. the respective overlap area, can be flushed, wherein gas or dry air can also advantageously be introduced to mix or dry the bulk material.

[0055] As can be seen in Fig. 2, at least one further friction disc 32, which is rotatably coupled to the drive shaft 21 and has opposing further friction surfaces 33, can be provided between the first friction disc 13 and the second friction disc 16, wherein the further friction surfaces 33 can be aligned normal to the drive rotation axis 22. Depending on the properties of the bulk material to be discharged, in particular with regard to its flowability, the distance between the first friction disc 13, the at least one further friction disc 32 and the second friction disc 16 can be selected such that bridging of the bulk material is possible between the friction surfaces 14 and 33 or between the friction surfaces 17 and 33, so that the bulk material can be advantageously compressed and discharged.

[0056] To further improve the bridging of the bulk material, the friction discs 13, 16, or 32 can have cavities 34 distributed over the respective friction surface 14, 17, or 33, starting from their respective friction surface 14, 17, or 33. Such cavities 34 can be designed, for example, as blind holes, as conical blind holes, as dents or dimples, or as grooves, scores, or slots. The cavities 34 distributed over the respective friction surface 14, 17, or 33 can thus increase the friction effect of the friction surfaces 14, 17, or 33, thereby improving the bridging of the bulk material and advantageously compressing and discharging the bulk material by means of the discharge device 1 in operation.

[0057] Fig. 3 shows an elevation of a section of a possible third and possibly independent embodiment of the discharge device 1 in a highly simplified and schematic representation, wherein the same reference numerals or component designations are used for the same parts as in the previous Fig. 1 and Fig. 2. To avoid unnecessary repetition, reference is made to the previous description. Fig. 3 shows a partial section of the housing 4, which partial section, among other things, in conjunction with the first flat wall 8 (not shown) and the second flat wall 9 (not shown), forms the conveying channel 5, which conveying channel 5, as described above, can have an inlet area 6 and a discharge area 7. Furthermore, Fig.3 shows the second friction disc 16, which, when the discharge device 1 is in operation, rotates about the second axis of rotation 18 in a direction of rotation 36. The discharge device 1 can, as can be seen from a combination of Fig. 3 and Fig. 2, further comprise a scraping element 35 or a respective scraping element 35 between two friction discs 13, 16 or 32, wherein the scraping element 35 or the respective scraping element 35 extends between two nearest friction discs 13, 16 or 32 or can span the distance between two nearest friction discs 13, 16 or 32. The scraping element 35 or the respective scraping element 35 can be fixed in position on the housing 4 and can extend from the housing 4 in the direction of the conveying channel 5 and preferably also in the direction of the inlet area 6. The scraping element 35 orthe respective scraping element 35 can be designed as a sheet metal or a sheet metal curved in the direction or in the direction opposite to the discharge direction 2, wherein the scraping element 35 or the respective scraping element 35 can have an angle 37 relative to the discharge direction 2 from a range comprising 5° to 90°, in particular 10° to 60°. The scraping element 35 or the respective scraping element 35 can furthermore be designed to protrude or project from the housing 4 up to the position of the respective axis of rotation 15, 18 or up to the position of the drive axis of rotation 22, wherein the scraping element 35 or the respective scraping element 35 is designed to be positionally fixed on that side of the housing 4, so that by means of the scraping element 35 or the respective scraping element 35, entrainment of ground material or bulk material can be prevented when the discharge device 1 is driven or when the friction disks 13, 16 or 32 are rotating against the discharge direction 2.Another advantageous embodiment is also conceivable, in which the scraping element 35 or the respective scraping element 35 is still fixed in position on the housing 4, but is also further adjustable in its angle 37, for example by means of a joint or a corresponding bearing, or at least in sections. It is also conceivable that the scraping element 35 or the respective scraping element 35 is variably adjustable in its positioning according to the properties of the bulk material, so that the angle 37 is variable. By providing and the previously described design of the scraping element 35 or the respective scraping element 35, not only is the grinding material or bulk material carried along when the driven discharge device 1 or when the respective friction disks 13, 16 or32 is prevented against the discharge direction 2, but the bulk material is further compressed by conveying it in the direction of the scraping element 35 or the respective scraping element 35 by means of the rotating friction discs 13, 16 or 32. It should be noted that a gap is provided between the scraping element 35 or between the respective scraping element 35 and the nearest friction disc 13, 16 or 32 in order to prevent the friction discs 13, 16 or 32 from coming into contact with the scraping element 35.

[0058] For the sake of clarity, it should finally be pointed out that, in order to better understand the structure, some elements have been shown out of scale and / or enlarged and / or reduced in size.

[0059] Reference symbol list

[0060] Discharge device 31 breakthrough

[0061] Discharge direction 32 Additional friction disc

[0062] Silo 33 Additional friction surfaces

[0063] Housing 34 cavities

[0064] Conveyor channel 35 scraping element

[0065] Inlet area 36 rotation direction

[0066] Application area 37 angle

[0067] First flat wall

[0068] Second flat wall

[0069] Normal direction

[0070] First angle of inclination

[0071] Second angle of inclination

[0072] First friction disc

[0073] First friction surface

[0074] First axis of rotation

[0075] Second friction disc

[0076] Second friction surface

[0077] Second axis of rotation

[0078] First drive motor second drive motor

[0079] drive shaft

[0080] Drive rotation axis

[0081] Roller or plain bearing device

[0082] ball flange

[0083] ball socket

[0084] Carrier-Org on

[0085] Starting element

[0086] thrust ring

[0087] deflector plate

[0088] Radial breakthrough

Claims

P a t e n t a n s p r ü c h e 1. Discharge device (1) for compressing and discharging non-free-flowing or poorly free-flowing ground material or fine-granular and / or conditionally free-flowing bulk material in a discharge direction (2) from a storage or silo (3), comprising a conveying channel (5) formed in sections by a housing (4) with an inlet area (6) and a discharge area (7), wherein the housing (4) has a first flat wall (8) and a second flat wall (9) opposite the first flat wall (8) along a normal direction (10) relative to the discharge direction (2), wherein the first flat wall (8) has a first angle of inclination (11) relative to the discharge direction (2) from a range comprising -1° to -60°, in particular -5° to -45°, and the second flat wall (9) has a second angle of inclination (12) relative to the discharge direction (2) from a range comprising 1° to 60°, in particular 5° to 45°,so that the conveying channel (5) is tapered in the discharge direction (2), characterized in that a first friction disc (13) is provided, which is closest to the first flat wall (8) within the conveying channel (5) and is rotatably mounted, and has a first friction surface (14) facing away from the first flat wall (8), and a second friction disc (16) is provided, which is closest to the second flat wall (9) within the conveying channel (5) and is rotatably mounted, and has a second friction surface (17) facing away from the second flat wall (9), wherein the first friction disc (13) is rotatable about a first axis of rotation (15) oriented normally relative to the first flat wall (8), and the second friction disc (16) is rotatable about a second axis of rotation (18) oriented normally relative to the second flat wall (9), and is drivably coupled to at least one first drive motor (19),so that when the first friction disc (13) and the second friction disc (16) are driven by the at least one first drive motor (19), the ground material or bulk material can be compressed by means of the friction surfaces (14, 17) and discharged in the discharge direction (2).

2. Discharge device (1) according to claim 1, characterized in that the first friction disc (13) is drivably coupled to the at least one drive motor (19) and the second friction disc (16) is drivably coupled to a second drive motor (20).

3. Discharge device (1) according to claim 1, characterized in that a drive shaft (21) penetrating the first flat wall (8) and the second flat wall (9) along the normal direction (10) is formed with a drive axis of rotation (22), - wherein the drive shaft (21) is rotatably coupled to the first drive motor (19), and - wherein the first friction disc (13) and the second friction disc (16) are each rotatably coupled to the drive shaft (21) and are each pivotably mounted relative to the drive rotation axis (22), wherein the first friction disc (13) is pivotably operatively coupled to the first flat wall (8) and the second friction disc (16) is pivotably operatively coupled to the second flat wall (9).

4. Discharge device (1) according to claim 3, characterized in that the first friction disc (13) and the second friction disc (16) are each mounted by means of a ball flange (24) on the drive shaft (21) with a respective associated ball socket (25) of the friction discs (13, 16) and are drivably coupled to the drive shaft (21) by means of a driver member (26) in operative connection with a starting element (27) for transmitting torque.

5. Discharge device (1) according to one of the preceding claims, characterized in that a roller or sliding bearing device (23) is provided or formed between a flat wall (8, 9) and a friction disc (13, 16) closest thereto.

6. Discharge device (1) according to claim 5, characterized in that the respective roller or plain bearing device (23) is designed as a thrust ring (28) and with the associated friction disc (13, 16) as a sliding pair, wherein the respective thrust ring (28) is formed from the softer material of the sliding pair.

7. Discharge device (1) according to claim 6, characterized in that the respective roller or sliding bearing device (23) has, in a section closest to the discharge area (7), a radial opening (30) extending in a circumferential direction of the roller or sliding bearing device (23).

8. Discharge device (1) according to one of the preceding claims, characterized in that the housing (4) in the inlet area (6) has a deflection plate (29) which is fixed in position to the first flat wall (8) and to the second flat wall (9), wherein the first friction disc (13) and the second friction disc (16) are partially covered by the respective deflection plate (29) in the discharge direction (2).

9. Discharge device (1) according to one of the preceding claims, characterized in that the first flat wall (8) and the second flat wall (9) have openings (31) in a respective overlap region of the first friction disc (13) and the second friction disc (16), respectively, wherein the openings (31) are pneumatically coupled to a gas supply device for introducing gas at an overpressure relative to the ambient pressure.

10. Discharge device (1) according to one of the preceding claims, characterized in that between the first friction disc (13) and the second friction disc (16) at least one further friction disc (32) is provided, which is rotatably coupled to the drive shaft (21) and has opposite further friction surfaces (33), wherein the further friction surfaces (33) are aligned normal to the drive rotation axis (22).

11. Discharge device (1) according to one of the preceding claims, characterized in that the friction discs (13, 16 or 32) have, starting from the respective friction surface (14, 17 or 33), a plurality of cavities (34) distributed over the respective friction surface (14, 17 or 33).

12. Discharge device (1) according to one of the preceding claims, characterized in that a scraping element (35) extending between two or respectively between two friction discs (13, 16 or 32) is formed on the housing (4) in a position-fixed manner, so that entrainment of ground material or bulk material can be prevented when the discharge device (1) is driven or when the friction discs (13, 16 or 32) are rotating in each case against the discharge direction (2).

13. Discharge device (1) according to claim 12, characterized in that the scraping element (35) or the respective scraping element (35) is designed as a sheet or component bridging the distance in the normal direction (10) between two friction discs (13, 16 or 32), wherein the scraping element (35) or the respective scraping element (35) essentially has an angle (37) relative to the discharge direction (2) from a range comprising 5° to 90°, in particular 10° to 60°.

14. Methods for quantifying or determining the bridging of bulk materials include the following steps: - Providing a discharge device (1) comprising - - a conveying channel (5) formed by a housing (4), wherein the housing (4) has a first wall (8) and a second wall (9) opposite the first wall (8), wherein the walls (8, 9) each have an angle of inclination (11, 12) relative to the discharge direction (2), so that the conveying channel (5) is tapered in the discharge direction (2), - - a first friction disc (13) closest to the first flat wall (8) within the conveying channel (5) and rotatable about a first axis of rotation (15) with a first friction surface (14) facing away from the first flat wall (8), - - a second friction disc (16) closest to the second flat wall (9) within the conveying channel (5) and rotatable about a second axis of rotation (18) with a second friction surface (17) facing away from the second flat wall (9), - wherein the first friction disc (13) is drivably coupled to a first drive motor (19) and the second friction disc (16) is drivably coupled to a second drive motor (20), and - - a control or regulating device coupled to the first drive motor (19) and the second drive motor (20); and - filling the conveyor channel (5) with bulk material; characterized in that the first drive motor (19) drives the first friction disc (13) with a predefined first torque and a predefined first speed according to a specification of the control or regulating device, wherein the second drive motor (20) is not driven and a second drive motor (20) is driven by the second friction disc (16) and by bridging the bulk material within the conveyor channel (5) by the first friction disc (13) transmitted second torque and a second speed are measured and recorded by means of the control or regulating device, so that a reference value for the bridging of the bulk material is determined by means of the control or regulating device.

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