Device and method for separating foreign bodies from a mass flow of small parts and use of the device

Abstract

Device 2 and method for separating foreign bodies from a mass stream M of small parts. The device 2 comprises: a feed device 4, which is configured to guide the mass stream M in a transport area 6 and convey it in a transport direction T; a detection device 8, which is configured to detect a foreign body F in the mass stream M; a rejection device 12, which is configured to pneumatically remove the foreign body F from the mass stream M by subjecting the foreign body F to a pulse directed transversely to the transport direction T of the mass stream M in a rejection direction R and thereby deflecting it; a discharge device 10, which is configured to receive and provide the mass stream cleaned of the foreign body F; and a foreign body receiving device 14, which is configured and arranged to receive the deflected foreign body F.The foreign body receiving device 14 has a shaft-shaped catching device 20 with at least one deflector element 26, wherein shaft walls 24a, 24b of the catching device 20 limit a catching volume V and the deflector element 26 is inclined by an angle α in a discharge plane E, in which the transport and discharge directions T, R lie, extending with its free end 30 into the catching volume V from a mounting position 28 on one of the shaft walls 24a, 24b, so that the free end 30 is arranged downstream of the mounting position 28 in the discharge direction R.

Description

[0001] The invention relates to a device for separating foreign particles from a mass stream of small parts. The invention further relates to the use of such a device. The invention also relates to a method for separating foreign particles from a mass stream using a device for separating foreign particles.

[0002] Devices for separating foreign bodies from a tobacco stream, as an example of a mass flow, are known. An example of such a device is described in EP 2 684 471 A1. In this device, a mass flow of tobacco fibers is fed from a feed device into a transport plane of the foreign body separation device. The foreign bodies are detected in the tobacco stream by a camera arrangement and blown downstream by means of a nozzle bar oriented transversely to the conveying direction of the tobacco stream. During this rejection process, the detected foreign body is selectively struck by a jet of air exiting the nozzle bar. The foreign body receives an impulse that deflects it from the conveying direction and directs it in a rejection direction to a foreign body collection device. The foreign bodies detected by the camera arrangement are precisely extracted by means of a jet of compressed air.Due to the high rejection rate, however, they enter the collection device, which is usually located below the mass flow, at high speed. It has been observed on several occasions that rejected foreign objects do not remain at the bottom of the collection device and cannot be removed from there, but instead bounce off the bottom and re-enter the cleaned mass flow. Thus, rejected foreign objects end up again, undesirably, in the good product. This reduces sorting efficiency and lowers the achievable quality of the good product stream.

[0003] It is an object of the invention to specify a device and a method for foreign body separation and furthermore the use of such a device, wherein the sorting efficiency of the foreign body separation is to be improved.

[0004] The problem is solved by a device for separating foreign particles from a mass stream of small parts, comprising: a feed device configured to guide the mass flow in a transport area and convey it in a transport direction; a detection device configured to detect a foreign body in the mass flow and to generate and transmit a foreign body detection signal; a rejection device configured to receive the foreign body detection signal and to pneumatically remove the foreign body from the mass flow by subjecting the foreign body to a pulse directed transversely to the transport direction of the mass flow in a rejection direction and thereby deflecting it; a discharge device configured to receive and provide the mass flow cleaned of the foreign body; a foreign body receiving device configured and arranged to receive the deflected foreign body, the device being further developed in this respect.that the foreign object receiving device has a shaft-shaped catching device with at least one deflector element, wherein shaft walls of the catching device define a catching volume and the deflector element is inclined at an angle in a ejection plane in which the transport and ejection directions lie, extending from a mounting position on one of the shaft walls with its free end into the catching volume, such that the free end is arranged downstream of the mounting position in the ejection direction.

[0005] The deflector element advantageously improves the sorting efficiency of the foreign body separation process. The deflector element, located in the shaft-shaped catching device, has two effects on the foreign bodies ejected from the mass flow. The first effect is an impact on a foreign body moving in the rejection direction. The second effect is an impact on a rebounding foreign body, which is moving essentially in the opposite direction to the rejection process and could, if it continues to move, escape the catching device again. It cannot be ruled out that such a foreign body could re-enter the good product flow.

[0006] According to its first effect, the deflector element ensures that a foreign object deflected in the direction of rejection is deflected at a shallow angle to the direction of rejection by impacting the upper surface of the deflector element towards a lower area of ​​the catching device located downstream of the direction of rejection. Since the deflector element is inclined relative to the direction of rejection, a direct rebound of the foreign object, deflecting it in a direction essentially opposite to the direction of rejection, is prevented. This significantly reduces the probability of the foreign object re-entering the good product stream. Should the foreign object, by chance, acquire a direction of movement opposite to the direction of rejection through one or more impacts, such a rebounding foreign object will, with some probability, strike an underside of the deflector element.Since the deflector element, as already mentioned, is inclined relative to the shaft wall of the catch device, the foreign object is deflected against the shaft wall after this impact. From there, the foreign object either rebounds against the underside of the deflector element or travels directly into lower areas of the catch device, which are located downstream of the impact point in the reject direction. The deflector element reduces the likelihood of the foreign object leaving the catch device in the direction of the good product flow. Both of these effects improve the sorting efficiency of the foreign object separation devices.

[0007] The collection device is preferably arranged geodesically below the mass flow, i.e., lower in the direction of gravity. During the sorting process, the mass flow passes over an upper opening of the collection device in a trajectory pattern. A separating edge at the upper opening of the collection device separates the ejected foreign matter from the product flow. In such an arrangement, foreign matter separation occurs with the additional effect of gravity. However, such an arrangement is by no means mandatory. The force of gravity acting on the foreign matter advantageously ensures that the deflected foreign matter reaches deeper into the collection device as a result of the effect of gravity. This reduces the probability that the foreign matter will be forced back into the product flow against gravity.

[0008] According to one embodiment, a conveyor belt is provided at the bottom of the trap located downstream in the direction of discharge, i.e., at the lower end of the trap. This conveyor belt extends with its transport surface, in particular perpendicular to the shaft walls. The conveyor belt is designed to transport the rejected foreign objects and thus remove them from the trap.

[0009] The conveyor belt replaces the triangular bottom plates used in many conventional debris collection devices. In conventional devices, these triangular bottom plates reduce the likelihood that ejected foreign objects, impacting the bottom of the device, will re-enter the product stream directly. A foreign object striking the upper surface of such a triangular plate is likely to be deflected towards a shaft wall, thus preventing it from re-entering the product stream directly against the direction of ejection. According to the invention, the debris collection device eliminates the need for triangular bottom plates due to the integrated deflection elements.The omission of triangular base plates allows the integration of a conveying device, in particular a flat conveyor belt, the upper side of which is oriented essentially perpendicular to the shaft walls, at the bottom of the catch device.

[0010] The trap acts as a kind of foreign object trap due to its at least one deflector element. The inclined deflector element, whose free end projects into the trapping volume—in other words, extending diagonally downwards from the shaft wall into the trapping volume—functions similarly to a fishbowl. It prevents the foreign objects from moving back.

[0011] The rejection direction extends, in particular, transversely and, in particular, perpendicularly to a transport surface in which the feed device guides the mass flow. The transport surface is, in particular, a plane. In practice, the rejection direction will vary depending on the mass of the foreign object to be rejected and also depending on the quality of the hit achieved by the rejection device, i.e., whether the foreign object is hit directly or, if applicable, only grazing the surface. An average rejection direction can be determined. For this purpose, an average value can be determined over a large number of rejection events, which is then adopted as the rejection direction.

[0012] The reject device is in particular a nozzle bar which extends transversely to the transport direction, in particular at least substantially perpendicular to the transport direction.

[0013] According to one embodiment, the device is further developed in that the catching device is cuboid, the deflecting element is plate-shaped, and the fastening position is linear.

[0014] The large flat sides of the cuboid-shaped catch device are oriented transversely to the deflection plane and, furthermore, at least substantially perpendicularly to the deflection plane. The shaft walls of the catch device are, in particular, rigidly constructed. The shaft walls are, for example, plate-shaped and made of metal. The deflector element is designed, for example, as a lamella extending transversely to the deflection plane and inclined obliquely downwards into the catch volume. It extends, in particular, along a linear attachment point. The lamella-shaped deflector element is attached to the shaft wall of the catch device at the linear attachment point with its long side edges.Starting from the shaft wall, the deflector element extends along its short side edge towards the containment volume. A deflector element designed as a lamella or plate has proven to be very efficient in practice.

[0015] According to one embodiment, the angle at which the deflector element is inclined is greater than or equal to 45°, and in particular lies between 45° and 60°. The angle is measured between a direction extending in the deflection plane from the mounting position to the free end of the deflector element and the ejection direction.

[0016] The specified angle ranges effectively prevent rejected foreign objects from rebounding. Firstly, an angle within the specified range ensures that a foreign object impacting the top of the deflector element, which is rejected from the mass flow in the rejection direction, enters the interior of the catching device at a shallow angle (first effect). This impact forces the foreign object deeper into the catching device. This prevents the foreign object from rebounding directly back into the mass flow, and thus the good product flow, as a result of a single impact in a direction opposite to the rejection direction. Secondly, a deflector element of this angle ensures that any foreign object rebounding off the bottom of the catching device is likely to strike an underside of the deflector element.From there, the foreign object is deflected towards the shaft wall to which the deflector is attached (second effect). This again efficiently prevents the foreign object from rebounding into the product flow. The angles mentioned are particularly well-suited for the intended function of the deflectors.

[0017] According to a further embodiment, the device is further developed in that the catching device has several deflecting elements. In particular, the deflecting elements are inclined at different angles. Furthermore, the angle at which the deflecting elements are inclined increases with increasing distance from the ejection device.

[0018] In other words, the deflectors are arranged at increasingly shallower angles the deeper they are positioned within the catch. Thus, the deflectors located in the upper part of the catch essentially create an impact on their upper surface, deflecting the impacting foreign objects deeper into the catch (first effect). The lower deflectors, arranged at a shallower angle, essentially provide the second effect, where any foreign objects that might rebound from the bottom of the catch are deflected against these elements from below. This shallow angle allows the catch to efficiently achieve the second effect, preventing the foreign objects from bouncing back.The impact from above (first effect), which is generally less favorable at shallower angles, plays only a minor role with these deflectors positioned deep within the catch device. Firstly, the kinetic energy of the ejected foreign objects is already reduced in the lower part of the catch device. Secondly, the ejected foreign objects are very likely to be deflected from their original direction by the deflectors located higher up.

[0019] The angle is measured in particular between a direction extending in the deflection plane from the mounting position to the free end of the deflection element and the deflection direction.

[0020] According to a further advantageous embodiment, the angle(s) of the deflector element(s) is / are adjustable.

[0021] The ability to adjust the angle(s) of one or more deflector elements allows for individual adaptation of the collection device to the specific sorting task. For example, the foreign object separation device can be adapted to the material of the mass flow and the type of foreign objects expected. This includes, for instance, adjustments based on the particle size or fiber length of the particles present in the mass flow. Similarly, adjustments can be made based on the size and / or mass of the expected foreign objects. The foreign object separation device can thus be optimally adapted to the intended or expected rejection process and the foreign objects being ejected.

[0022] According to a further advantageous embodiment, the device is further developed in that the shaft walls are partially permeable to air, in particular having air-permeable areas, wherein the air-permeable areas are arranged in a section of the shaft wall whose dimensions are defined by a projection of the deflector element onto a surface, in particular a plane, of the shaft wall, wherein air-permeable grids and / or sieves are integrated into the shaft walls, in particular as air-permeable areas.

[0023] During the rejection process, foreign objects are ejected from the mass flow by means of a blast of air. With a large number of rejection processes, the air blasts used to remove individual foreign objects can add up to a considerable volume flow. In other words, a high number and frequency of rejection processes can lead to an airflow directed into the collection volume, resulting in overpressure within the collection device. This overpressure could only be released through the inlet opening of the collection device, i.e., in the direction of the mass flow from which the foreign objects are being removed. This would create an airflow directed against the direction of rejection.This effect can cause ejected foreign matter to float in the described airflow against the direction of rejection and be transported in the direction of the good product flow, or at least be carried away in the direction of rejection at a reduced speed. To avoid this effect, or at least to reduce it quantitatively, air-permeable areas are provided in the shaft walls. Any overpressure that may build up in the collection volume can dissipate quickly through these air-permeable areas. This further improves the extraction of foreign matter.

[0024] According to a further advantageous embodiment, the device is further developed in that the catching device is cuboid in shape and the opposing large flat sides of the cuboid form a first and a second shaft wall, wherein the first and second shaft wall each extend in a plane transversely, in particular perpendicularly, to the ejection plane and the ejection direction runs at least approximately parallel to the planes, wherein at least one deflector element is provided on the first and second shaft wall.

[0025] The effectiveness of the intercepting device can be improved by placing deflector elements on the opposing shaft walls, i.e., on both shaft walls of the intercepting device. Such a device can be further developed by arranging the deflector elements on different shaft walls at varying distances from the ejection device. In other words, the deflector elements can be arranged opposite each other, i.e., at the same height, viewed in a cross-section parallel to the deflection plane, or offset from each other on the opposing shaft walls.

[0026] According to a further embodiment, it is also provided that several deflector elements are present on both the first and second shaft walls. Viewed in the direction of discharge, the deflector elements arranged on the first shaft wall are positioned between the deflector elements arranged on the second shaft wall. In other words, the deflector elements on alternating shaft walls are arranged alternately offset from one another.

[0027] The mounting positions of the deflectors on the first shaft wall define a variety of different first distances from the reject device. Similarly, the mounting positions of the deflectors on the second shaft wall define a variety of different second distances from the reject device. The mounting positions on the first shaft wall are positioned between the mounting positions on the second shaft wall, and vice versa. Thus, the deflectors on the first shaft wall are offset from the deflectors on the second shaft wall, and vice versa. For example, the first mounting positions on the first shaft wall are each located midway between the second mounting positions on the second shaft wall, viewed in the deflector plane.The same applies, of course, to the fastening position on the second shaft wall, which is located, in particular, centrally between the fastening positions of the deflector elements on the first shaft wall.

[0028] The staggered arrangement of the deflecting elements has proven in practice to be an efficient measure for improving sorting efficiency.

[0029] The device is further developed according to another embodiment in that the free ends of the deflecting elements located on the first and second shaft walls, viewed in a plane perpendicular to the discharge direction, maintain a distance from each other, such that a channel extending in the discharge direction is present between the free ends of the deflecting elements arranged on different shaft walls, wherein in particular the channel has a width, viewed in the plane perpendicular to the discharge direction and in a direction perpendicular to the shaft walls, which is between 25% and 35% of a clear width between the shaft walls.

[0030] By providing a channel between the free ends of the deflecting elements, the probability is improved that ejected foreign objects will enter the catch device directly with their initial movement, i.e., before an impact event occurs. The probability of such foreign objects re-entering the product stream is low. Such a design of the catch device is therefore advantageous.

[0031] According to a further advantageous embodiment, it is further provided that the at least one deflecting element is pivotably hinged at least section by section at the mounting position in such a way that the angle of the deflecting element can be changed at least section by section, wherein in particular a return element is provided on the deflecting element which is designed to exert a return force on the deflecting element in the direction of a rest position.

[0032] The restoring force of the deflecting elements is specifically dimensioned to return them to their rest or initial position, counteracting the force of gravity exerted by the deflecting element's own weight. This restoring force can be chosen to be only slightly greater than necessary to overcome the corresponding force of gravity. In other words, the deflecting elements can be pivoted against the restoring force by even small forces. An impacting foreign object is thus able to pivot the deflecting element out of its rest position against the restoring force. If the deflecting element pivots back to its initial position within a short time, it can, according to the second effect, very likely provide an obstacle to the foreign object impacting the underside of the deflecting element.A foreign object moving against the direction of rejection, towards the good product flow, can very likely be prevented from doing so. In the opposite direction, i.e., in the direction of rejection, the deflector element exerts only a slight force on the foreign object, thus deflecting it only minimally from the direction of rejection. The foreign object transported in the direction of rejection is only slightly deflected and enters the catching device deeply.

[0033] According to an advantageous embodiment, it is further provided that the deflecting element is plate-shaped and is pivotably hinged section by section in an extension direction transverse to the ejection direction, so that individual plate sections of the deflecting element can be pivoted freely independently of one another, wherein the plate sections are each provided with a return element.

[0034] The segmented design of the deflector element, as a pivotable deflector element, further improves the aforementioned effect. The deflector element is only deflected from its rest position in the area where it is struck on its upper surface by a foreign object. The remaining area of ​​the deflector element still provides a large cross-section for foreign objects moving in the opposite direction of deflection, such as those that rebound off the base of the catch device (second effect). Thus, an optimal catch effect, based on both the first and second effects, can be selectively provided by the segmentally movable deflector elements.

[0035] According to a further advantageous embodiment, the device is further developed in that the deflecting element is designed to be elastically deformable at least partially or completely, wherein in particular the deflecting element has an elastically deformable section, and wherein in particular the elastically deformable section comprises the free end of the deflecting element.

[0036] In particular, it is provided that the elastically deformable area of ​​the deflecting elements is continued in such a way that there is no or only a very small clear width between the free ends of the deflecting elements.

[0037] Partially or fully elastically deformable deflecting elements include, for example, a brush strip or a flexible lip, such as a rubber lip. A fully elastically deformable deflecting element can be formed entirely by the individual bristles of a brush strip or by the rubber lip. The elastically deformable area of ​​the deflecting element can, in turn, be locally limited. The deflecting element, for example, individual bristles of a brush strip or a section of a rubber lip, can therefore be deflected locally in the direction of the object being rejected. If the deflecting element is only slightly elastically deformable, meaning that only a small force is required to cause the deformation, the impacting foreign object will accordingly be deflected only slightly.The flexible area quickly returns to its starting position, so that any foreign object that may rebound from the bottom of the catching device, moving in the opposite direction to the rejection direction, impacts the underside of the deflecting element, in particular the underside of the elastically deformable area of ​​the deflecting element, and does not return to the good product stream.

[0038] A nozzle bar is used as the reject device. A camera arrangement, for example, a camera arrangement comprising several cameras, is used as the detection device. This camera arrangement can be configured to view the mass flow from one side, for example, from the top. Likewise, the camera arrangement can be configured to view the mass flow from both the top and the bottom and to detect foreign bodies. The catching device has a dimension, viewed in the reject direction, of less than 2 m, and in particular a dimension in the range between 1 m and 1.5 m. This dimension is the depth of the catching device, measured, for example, from an upper separating edge to the bottom of the catching device. The width of the catching device is adapted to the transport width of the mass flow, as is the width of the reject device.the nozzle bar.

[0039] The problem is further solved by using a device according to one or more of the aforementioned embodiments for separating foreign bodies from a mass flow, in particular from a mass flow of the tobacco processing industry. The mass flow of the tobacco processing industry is, for example, a mass flow of tobacco material, such as a mass flow of small tobacco particles.

[0040] The use of the device offers the same or similar advantages and further training opportunities as those already mentioned with regard to the device itself, so repetition is unnecessary.

[0041] The problem is further solved by a method for foreign body separation from a mass stream with a foreign body separation device comprising: a feed device that guides the mass flow in a transport area and conveys it in a transport direction, a detection device that detects a foreign body in the mass flow and generates and transmits a foreign body detection signal, a rejection device that receives the foreign body detection signal and pneumatically removes the foreign body from the mass flow by subjecting the foreign body to a pulse directed transversely to the transport direction of the mass flow in a rejection direction and thereby deflecting it, a discharge device that receives and provides the mass flow cleaned of the foreign body, a foreign body receiving device that receives the deflected foreign body, wherein this method is further developed in that the foreign body receiving device has a shaft-shaped catching device with at least one deflecting element,wherein the shaft walls of the catch device define a catch volume and the deflecting element is inclined at an angle in a discharge plane in which the transport and discharge directions lie, extending from a mounting position on one of the shaft walls with its free end into the catch volume, such that the free end is arranged downstream of the mounting position in the discharge direction, wherein the deflected foreign body is received in the foreign body receiving device.

[0042] The same or similar advantages and further training opportunities apply to the method for foreign body separation from a mass stream as were mentioned directly with regard to the device for foreign body separation, so repetition will be omitted.

[0043] Further features of the invention will become apparent from the description of embodiments according to the invention, together with the claims and the accompanying drawings. Embodiments according to the invention may fulfill individual features or a combination of several features.

[0044] The invention is described below, without limiting the general concept of the invention, with reference to exemplary embodiments and the drawings, whereby for all details of the invention not explained in detail in the text, explicit reference is made to the drawings. The drawings show: Fig. 1 a device for foreign body separation from a mass stream with a feed device and a discharge device in a simplified perspective view, Fig. 2 the from Fig. 1 known device, wherein the dispensing device is not shown and the feeding device and a foreign body receiving device (Fig. 3) are shown in partial section, which are derived from the representation of Fig. 2 Fig. 4 shows a known device from a different perspective; Fig. 5 shows a further representation of the device for foreign body separation in a sectional view in a reject plane; Fig. 6 shows a further detail view of a device for foreign body separation in a sectional view; Fig. 7 shows a further device for foreign body separation in a perspective, partially cutaway detail view; Fig. 8 shows a further detail view of another device for foreign body separation in a sectional view; and

[0045] Within the scope of the invention, features marked with "in particular" or "preferably" are to be understood as optional features.

[0046] In the drawings, identical or similar elements and / or parts are provided with the same reference numbers, so that a re-presentation is omitted.

[0047] Fig. 1 Figure 2 shows a device for separating foreign bodies from a mass stream of small parts (not shown). These small parts are, for example, components from the tobacco processing industry, such as tobacco pulp, reconstituted tobacco material, or tobacco fibers. The mass stream can also consist of small parts not related to the tobacco processing industry, such as small food products or other small objects.

[0048] The device 2 comprises a feed device 4, which is configured to guide the mass flow in a transport surface 6. The feed device 4 is, for example, a conveyor belt guided by guide rollers (not marked with reference numerals). The transport surface 6 is, for example, a plane or is nearly flat. The feed device 4 is configured to convey the mass flow in a transport direction T. At the end of the feed device 4 is a detection device 8, for example, a camera arrangement. The detection device 8 is configured to image and analyze the mass flow guided on the feed device 4. (Deviating from the representation in...) Fig. 1 The detection device 8 can also be designed in such a way that the mass flow is detected not only from the top, as indicated by limiting rays in the figure, but alternatively or simultaneously from the bottom.

[0049] Starting from the feed device 4, the mass flow travels in the transport direction T along a flight parabola to a discharge device 10. During its flight, the small parts of the mass flow pass a rejection device 12 and a foreign object receiving device 14.

[0050] The discharge device 10 is designed to receive the cleaned mass flow, also referred to as the good product flow, from the feed device 4 and make it available for further processing. The discharge device 10 is, for example, a conveyor belt guided around deflection rollers that are not marked with reference numerals.

[0051] During the flight phase of the mass flow from the feed device 4 to the discharge device 10, it passes the rejection device 12, which is, for example, a pneumatically operated nozzle bar. The detection device 8 is configured to detect a foreign body present in the mass flow and to generate a foreign body detection signal S and send it to the rejection device 12.

[0052] The ejection device 12 is configured to receive the foreign body detection signal S and to eject the foreign body present in the mass flow during its free-flight phase. The foreign body is pneumatically removed from the mass flow by being deflected from the transport direction T in the direction of an ejection direction R by a compressed air pulse emitted from the ejection device 12, which is designed, for example, as a nozzle bar. The ejection direction R is the direction in which the air pulse intended to eject the foreign body is emitted by the ejection device 12. The resulting trajectory of the foreign body is determined by appropriate vector addition. It essentially corresponds to the ejection direction R, provided the compressed air pulse is sufficiently strong. Through the ejection process, the foreign body enters the foreign body receiving device 14, which is designed and arranged to receive the deflected foreign body.

[0053] The foreign object receiving device 14 has a separating element 16, which is a plate-shaped, lamellar element whose longitudinal direction is oriented transversely to the transport direction T. The separating element 16 has an upper separating edge 18 facing the mass flow, which separates the foreign objects from the good product flow. Therefore, unless the foreign objects are extracted more or less directly from the mass flow in the rejection direction R, for example, because the airflow used for rejection does not strike the foreign object centrally but only grazes it, the foreign objects collide with the separating element 16. Fig. 1 on the underside of the separating element 16 facing away from the separating element. From there they enter the foreign body receiving device 14.

[0054] The foreign object receiving device 14 comprises, in addition to the separating element 16 and the catching device 20, a collection container 22 in which the separated foreign objects are collected and transported away. For the removal of the foreign objects, a conveyor belt (not shown) is provided, for example, in the lower part of the collection container 22.

[0055] Fig. 2 shows the from Fig. 1 A known device 2 for foreign body separation is shown, with the discharge device 10 not depicted. The feed device 4 and the foreign body receiving device 14 are also shown in partial section. The shaft-shaped trapping device 20 has opposing shaft walls 24a, 24b, which define a cuboid trapping volume V on their large side faces. Within the trapping volume V of the trapping device 20 are deflector elements 26, each extending into the trapping volume V with its free ends 30 from a mounting position 28 located on the shaft wall 24a, 24b. By way of example, several deflector elements 26 are arranged on each of the two shaft walls 24a, 24b, of which only one is labeled for clarity. The same applies to the mounting positions 28 and the respective free ends 30.

[0056] Fig. 3 shows the from Fig. 2 Known device 2 from a different perspective. In this illustration, it can be seen that not only are deflecting elements 26 present on the second shaft wall 24b, but that the first shaft wall 24a is also provided with deflecting elements 26.

[0057] The transport direction T and the rejection direction R (see above). Fig. 1 ) define a committee level E. Fig. 4 Figure 1 shows a further representation of the device 2 for foreign body separation in a sectional view in the reject plane E or a plane parallel to the reject plane E. The reject plane E is located in the representation of Fig. 4 in the drawing plane.

[0058] Fig. 4 Figure 2 shows, in addition to the already known components of the device 2, the mass flow M in which foreign bodies F are present, shown schematically and in isolated instances. Starting from the feed device 4, the foreign bodies F travel along a trajectory path T with the mass flow M into the operating area of ​​the reject device 12, after having been detected in the mass flow M by the detection device 8. A targeted pneumatic impulse imparts a momentum to the foreign bodies F, directed in the rejection direction R. In this way, the foreign bodies F are deflected towards the collection volume V and enter the collection device 20. The deflecting elements 26, of which only one is labeled, are inclined at an angle α relative to the shaft wall 24a, 24b in the rejection plane E.Thus, the free end 30 of the deflecting elements 26 is located downstream of the fastening position 28 in the direction of rejection R.

[0059] The catch device 20 is, for example, cuboid in shape. The deflector element(s) 26 are, for example, plate-shaped. The catch device 20 and the deflector elements 26 are, for example, made of metal. The mounting position 28 is, for example, linear. Along this linear mounting position 28, the deflector element 26 is attached to the respective shaft wall 24a, 24b with its large side edge. The angle α, by which the deflector elements 26 are moved according to the [reference] Fig. 4 In the illustrated embodiment, the angle α is greater than or equal to 45°. For example, the angle α lies within an interval between 45° and 60°, whereby both an open interval, which excludes the limiting values, and a closed interval, which includes the limiting values, can be provided. The angle α is measured between a direction 32, which extends in the deflection plane E from the mounting position 28 to the free end 30 of the deflection element 26, and the rejection direction R. In the illustration of Fig. 4 The angle α between this direction 32 and the second shaft wall 24b is shown. Since the shaft wall 24b is parallel to the discharge direction R, the angle α shown corresponds to the previously mentioned definition.

[0060] The catch device 20 of the device 2 shown in the embodiments described so far has several deflecting elements 26. In the Fig. 4 In the illustrated embodiment, all deflecting elements 26 are inclined by an identical angle α.

[0061] Fig. 5 Figure 1 shows a detailed view of another device 2, whose catch device 20 has deflector elements 26 inclined at different angles α1, α2, α3. For example, α1 is greater than α2, and α3 is greater than α3. In other words, the angle α at which the deflector elements 26 are inclined increases with increasing distance from the ejector device 12 shown in section. Similarly, the length of the deflector elements 26, measured between a mounting position 28 and a free end 30, can be seen in the figure. Fig. 5 denoted by a, b, c, with increasing distance from the ejection device 12, ab. In other words, a is greater than b is greater than c.

[0062] The deflecting elements 26 arranged in the catching device 20 have essentially a first and a second effect on the foreign bodies F deflected by the rejecting device 12. The deflecting elements 26 exert their first effect when a foreign body F impacts a top surface 32 of the deflecting element 26 in the rejection direction R. This impact event causes the foreign body F to be deflected in a first deflection direction, which is shown with a dashed arrow. The position of the foreign body F shortly after the impact event is also shown with a dashed line. It is important that the foreign body F is deflected in a direction that differs significantly from the rejection direction R. Thus, the probability that the foreign body F will return to the good product stream G, which is free of foreign bodies F, is reduced. Fig. 4 The second effect of the deflector element 26 will be explained using the example of a foreign body F'. For instance, it is assumed that the foreign body F' has bounced off the bottom of the collection container 22 and is now moving in a return direction B, opposite to the discharge direction R. Such a foreign body will very likely collide with an underside 34 of the deflector element 26 and be deflected there in a direction indicated by a dashed arrow. The foreign body F' will next collide with an inner surface of the second shaft wall 24b, and further collisions between the underside 34 and the second shaft wall 24b are very likely to occur. During these collisions, the foreign body F' dissipates kinetic energy and finally, due to friction from gravity, enters the collection container 22. A rebound of the foreign body F' into the good product stream G can thus be effectively prevented.

[0063] Fig. 6 Figure 1 shows a further detailed view of a device 2 for foreign body separation. The trap 20 is provided with deflector elements 26 whose angle of inclination α is adjustable. The angle of inclination α can be adjustable for some or all of the deflector elements 26 arranged in the trap 20. The different angles α by which the inclination of the deflector elements 26 can be adjusted are represented by the different indicated positions of the deflector elements 26. The adjustability of the deflector elements 26 can be achieved by a manually operated adjustment device. Alternatively, a motor-driven adjustment device can be provided, for example, with which the angle α of one or more of the deflector elements 26 can be changed.

[0064] If a large number of rejection operations take place with the rejection device 12, the sum of the individual pneumatic pulses can result in a considerable airflow directed into the collection volume V. This can lead to an overpressure building up within the collection volume V, which could only be relieved via the inlet opening 36 of the collection device 20 (see Figure 1). Fig. 4 A backflow would occur towards the inlet opening 36, which is directed against the discharge direction R. To avoid this effect, the shaft walls 24a, 24b are designed to be partially air-permeable. The shaft walls 24a, 24b thus include air-permeable areas 38, which are designed, for example, as a grid or mesh. Any overpressure that may develop in the collection volume V can dissipate via the air-permeable areas 38. In other words, the air-permeable areas 38 prevent the previously described backflow from forming in the first place.

[0065] The air-permeable areas 38 are integrated, by way of example, into the shaft walls 24 located below the deflector elements 26. This allows excess air from the collection volume V to escape from the collection volume V in such an area, where the foreign bodies F are reliably prevented from flowing back into the product flow G. If the foreign bodies F are carried along by the airflow escaping through the air-permeable areas 38, impact processes will very likely occur, as described in connection with the second effect in the context of Fig. 5 were described.

[0066] As mentioned previously, the catching device 20 is exemplarily cuboid in shape. The opposing large flat sides of this cuboid are formed by the first and second shaft walls 24a, 24b. The first and second shaft walls 24a, 24b each extend transversely in a plane, in particular perpendicularly to the ejection plane E (cf. Fig. 4 The discharge direction R runs at least approximately parallel to these planes in which the large flat sides of the cuboid extend. At least one deflector element 26 is present on each of the first and second shaft walls 24a, 24b; in particular, several deflector elements 26 are provided per shaft wall 24a, 24b.

[0067] Furthermore, it is provided, for example, that the deflecting elements 26 present on the different shaft walls 24a, 24b are arranged at different distances from the ejection device 12 (cf. Fig. 5 This is an example of how in the Fig. 2 bis 5 It can be seen that several deflecting elements 26 are present on each of the first and second shaft walls 24a, 24b, which are arranged alternately offset to each other in the direction of discharge R between the first and second shaft walls 24a, 24b.

[0068] Furthermore, it is provided that a channel 40 is formed between the free ends 30 of the deflecting elements 26 located on opposite shaft walls 24a, 24b. In the lower area of ​​the catch device 20, as it is in Fig. 4 As shown, the channel 40 is indicated by a dotted line. The free ends 30 of the deflecting elements 26 located on the first and second shaft walls 24a, 24b, viewed in a plane perpendicular to the discharge direction R, particularly in the discharge plane E, maintain a distance A from each other. Thus, a channel 40 extending in the discharge direction R can form between the free ends 30 of the deflecting elements 26 arranged on the different shaft walls 24a, 24b. The channel 40 has a width defined by the distance A. Viewed in the plane perpendicular to the discharge direction R and in a direction perpendicular to the shaft walls 24a, 24b, this width is between 25% and 35% of the clear width between the shaft walls 24a, 24b. The clear width between the shaft walls 24a, 24b is measured as the distance between the inner sides of the shaft walls 24a, 24b, measured in a direction perpendicular to their surface.

[0069] The deflecting elements 26 can be pivotally hinged at least partially at the mounting position 28. The angle α of the deflecting element 26 is therefore variable, at least partially. For example, the angle α of the deflecting element 26 can be changed as shown in Fig. 6 The different representations of the deflector element 26 indicate that it can change. Furthermore, a return element, such as a return spring, is provided on the deflector element 26. The return element is designed to exert a restoring force on the deflector element 26 in the direction of a starting position, at which the angle α by which the deflector element 26 is inclined is, for example, at its maximum. In other words, the return element always returns the deflector element 26 to its rest or starting position. The pivotability of the deflector element 26 can be implemented section by section. A corresponding deflector element 26 is, for example, constructed from individual separate plate sections 42.

[0070] Fig. 7 Figure 2 shows a further device 2 for foreign body separation, which has a catching device 20 whose deflector elements 26 are segmented and constructed from individual plate sections 42, only some of which are provided with reference numerals. Such a deflector element 26 is pivotally mounted section by section in an extension direction D transverse to the discharge direction R, so that the individual plate sections 42 of the deflector element 26 can pivot freely independently of one another. Each of the plate sections 42 is provided with a return element so that the plate sections 42 can pivot individually. It is further provided, for example, that only the uppermost deflector element 26, i.e., the one which is located closest to the inlet opening 36, is constructed from individual plate sections 42. The remaining deflector elements 26 located downstream in the discharge direction R can be constructed as a single piece.

[0071] Fig. 8 Figure 1 shows a further detailed view of a device 2 for foreign body separation, whose catching device 20 has deflector elements 26 whose mounting positions 28 are at the same height. In other words, these deflector elements 26 are not offset from one another. The deflector elements 26 are designed to be elastically deformable, at least in part. For this purpose, the deflector elements 26 comprise an elastically deformable section 44, which includes the free end 30 of the deflector element 26. The different possible positions of the deformable section 44 are shown in Fig. 8 indicated by different positions. For example, the elastically deformable section 44 is a rubber lip or a brush strip.

[0072] All features mentioned, including those discernible from the drawings alone as well as individual features disclosed in combination with other features, are considered essential to the invention, both individually and in combination. Inventive embodiments may be fulfilled by individual features or by a combination of several features. Bezugszeichenliste

[0073] 2 Foreign body separation device 4 Feed device 6 Transport surface 8 Detection device 10 Discharge device 12 Reject device 14 Foreign body receiving device 16 Separating element 18 Separating edge 20 Catching device 22 Collection container 24 First shaft wall 24 Second shaft wall 26 Deflector elements 28 Mounting position 30 Free end 32 Direction 33 Top 34 Bottom 36 Inlet opening 38 Air-permeable area 40 Channel 42 Plate section 44 Deformable section T Transport direction S Foreign body detection signal R Rejection direction V Capture volume E Rejection level M Mass flow F Foreign body G Good product flow B Return direction A Distance DE Extension direction α Inclination angle

Claims

1. Device (2) for separating foreign bodies from a mass stream (M) of small parts, comprising: - a feed device (4) configured to guide the mass stream (M) in a transport area (6) and convey it in a transport direction (T), - a detection device (8) configured to detect a foreign body (F) in the mass stream (M) and to generate and transmit a foreign body detection signal (S), - a rejection device (12) configured to receive the foreign body detection signal (S) and to pneumatically remove the foreign body (F) from the mass stream (M) by subjecting the foreign body (F) to a pulse directed transversely to the transport direction (T) of the mass stream (M) in a rejection direction (R) and thereby deflecting it, - a discharge device (10) configured to receive and provide the mass stream cleaned of the foreign body (F), - a foreign body receiving device (14),which is set up and arranged to receive the deflected foreign body (F), , characterized by the fact that - the foreign body receiving device (14) has a shaft-shaped catching device (20) with at least one deflector element (26), wherein shaft walls (24a, 24b) of the catching device (20) define a catching volume (V) and the deflector element (26) is inclined by an angle (α) in a discharge plane (E) in which the transport and discharge directions (T, R) lie, extending with its free end (30) into the catching volume (V) from a mounting position (28) on one of the shaft walls (24a, 24b), so that the free end (30) is arranged downstream of the mounting position (28) in the discharge direction (R).

2. Device (2) according to claim 1, characterized by the fact that the catching device (20) is cuboid, the deflecting element (26) is plate-shaped and the fastening position (28) is linear.

3. Device (2) according to claim 1 or 2, characterized by the fact thatthe angle (α) is greater than or equal to 45°, in particular between 45° and 60°, wherein the angle (α) is measured between a direction (32) extending in the deflection plane (E) from the mounting position (28) to the free end (30) of the deflection element (26) and the ejection direction (R).

4. Device (2) according to any one of claims 1 to 3, characterized by the fact that the catching device (20) has several deflecting elements (26), wherein the deflecting elements (26) are inclined by different angles (α1, α2, α3), wherein in particular the angle (α) by which the deflecting elements (26) are inclined increases with increasing distance from the ejection device (12).

5. Device (2) according to any one of claims 1 to 4, characterized by the fact that the angle(s) (α) is / are adjustable.

6. Device (2) according to any one of claims 1 to 5, characterized by the fact thatthe shaft walls (24a, 24b) are partially permeable to air, in particular having air-permeable areas (38), wherein the air-permeable areas (38) are furthermore arranged in a section of the shaft wall (24a, 24b) whose dimensions are defined by a projection of the deflector element (26) onto a surface, in particular a plane, of the shaft wall (24a, 24b), wherein air-permeable grids and / or screens are furthermore integrated into the shaft walls (24a, 24b) as air-permeable areas (38).

7. Device (2) according to any one of claims 1 to 6, characterized by the fact thatthe catching device (20) is cuboid in shape and the opposing large flat sides of the cuboid form a first and a second shaft wall (24a, 24b), wherein the first and second shaft walls (24a, 24b) each extend in a plane transverse, in particular perpendicular, to the ejection plane (E) and the ejection direction (R) runs at least approximately parallel to the planes, wherein at least one deflecting element (26) is present on each of the first and second shaft walls (24a, 24b).

8. Device (2) according to claim 7, characterized by the fact that the deflecting elements (26) present on different shaft walls (24a, 24b) are arranged at different distances from the ejection device (12).

9. Device (2) according to claim 7 or 8, characterized by the fact thatSeveral deflecting elements (26) are present on the first and second shaft walls (24a, 24b), which are arranged alternately offset from each other in the direction of discharge (R) between the first and second shaft walls (24a, 24b).

10. Device (2) according to any one of claims 7 to 9, characterized by the fact thatthe free ends (30) of the deflecting elements (26) located on the first and second shaft walls (24a, 24b), viewed in a plane perpendicular to the discharge direction (R), maintain a distance (A) from each other, such that a channel (40) extending in the discharge direction (R) is present between the free ends (30) of the deflecting elements (26) arranged on different shaft walls (24a, 24b), wherein in particular the channel (40) has a width, viewed in the plane perpendicular to the discharge direction (R) and in a direction perpendicular to the shaft walls (24a, 24b), which is between 25% and 35% of a clear width between the shaft walls (24a, 24b).

11. Device (2) according to any one of claims 1 to 10, characterized by the fact thatthat at least one deflecting element (26) is pivotably articulated at least section by section at the mounting position (28) such that the angle (α) of the deflecting element (26) can be changed at least section by section, wherein furthermore, in particular, a restoring element is provided on the deflecting element (26) which is designed to exert a restoring force on the deflecting element (26) in the direction of a rest position.

12. Device (2) according to claim 11, characterized by the fact that the deflecting element (26) is plate-shaped and is pivotably mounted section by section in an extension direction (D) transverse to the ejection direction (R), so that individual plate sections (42) of the deflecting element (26) can pivot freely independently of one another, wherein the plate sections (42) are each provided with a return element.

13. Device (2) according to any one of claims 1 to 12, characterized by the fact thatthe deflecting element (26) is designed to be elastically deformable at least in sections or completely, wherein in particular the deflecting element (26) has an elastically deformable section (44), and wherein in particular the elastically deformable section (44) comprises the free end (30) of the deflecting element (26).

14. Use of the device (2) according to any one of claims 1 to 13 for separating foreign bodies (F) from a mass stream (M), in particular from a mass stream (M) of the tobacco processing industry, and furthermore in particular from a mass stream (M) of tobacco material or a mass stream of small tobacco parts.

15. Method for foreign body separation from a mass flow (M) with a foreign body separation device (2), comprising: - a feed device (4) that guides the mass flow (M) in a transport area (6) and conveys it in a transport direction (T), - a detection device (8) that detects a foreign body (F) in the mass flow (M) and generates and transmits a foreign body detection signal (S), - a rejection device (12) that receives the foreign body detection signal (S) and pneumatically removes the foreign body (F) from the mass flow (M) by subjecting the foreign body (F) to a pulse directed transversely to the transport direction (T) of the mass flow (M) in a rejection direction (R), thereby deflecting it, - a discharge device (10) that receives and provides the mass flow cleaned of the foreign body (F), - a foreign body receiving device (14) that receives the deflected foreign body (F), characterized by the fact that- the foreign body receiving device (14) has a shaft-shaped catching device (20) with at least one deflecting element (26), wherein shaft walls (24a, 24b) of the catching device (20) define a catching volume (V) and the deflecting element (26) is inclined by an angle (α) in a discharge plane (E) in which the transport and discharge directions (T, R) lie, extending from a mounting position (28) on one of the shaft walls (24a, 24b) with its free end (30) into the catching volume (V), such that the free end (30) is arranged downstream of the mounting position (28) in the discharge direction (R), wherein the deflected foreign body (F) is received in the foreign body receiving device (14).

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