Device and method for screening a materials mixture

Abstract

The invention relates to a device for sifting a material mixture (M) consisting of multiple materials (M1-M4) or multiple material groups, wherein the device (1) comprises a first transport unit (10) into which the material mixture (M) to be sifted can be deposited by a supply device (2), and a second transport unit (20) arranged downstream in a transport direction of the material mixture (M) and spaced apart from the first transport unit (10), wherein a first chute (100a) is provided between the first transport unit (10) and the second transport unit (20), via which a first material (M1) or a first material group with a first fluid resistance can be separated from the material mixture (M). According to the invention, the device (1) comprises at least one third transport unit (30) arranged downstream of the second transport unit (20) in the transport direction of the material mixture (M) and spaced apart from same, such that a transit route (101) for the materials (M2, M3, M4) or material mixtures is formed between the second transport unit (20) and the third transport unit (30), and such that a second chute (100b) is provided between the second and the third transport unit (20, 30), via which at least the second material (M2) or the second material group with a second fluid resistance can be separated from the material mixture (M), and such that the third transport unit (30) is designed so that material can pass through and / or a fluid flow (S3; S3', S3") can pass through.

Description

[0001] The invention relates to a device for screening a material mixture consisting of several materials or several material groups, wherein the device has a first transport unit, into which the material mixture to be screened can be fed by a feed device, and a second transport unit following in a transport direction of the material mixture and arranged at a distance from the first transport unit, wherein a first chute is provided between the first transport unit and the second transport unit, via which a first material or a first material group with a first fluid resistance can be separated from the material mixture, a use of this device and a method for screening such a material mixture,in which the material mixture to be screened is transferred from a first transport unit to a second transport unit arranged downstream of and at a distance from the first transport unit in a transport direction of the material mixture, and the first material or the first group of materials is discharged with a first fluid resistance through a first chute located between the first and the second transport unit, and the remaining portion of the material mixture is transferred to the second transport unit.

[0002] US 2014 / 0102955 A1 discloses a device according to the preamble of claim 1 and a method according to the preamble of claim 8 for sifting a material mixture. The device comprises several transport units with conveyor belts arranged at a distance from one another. A chute is provided between two adjacent transport units, through which a portion of the material mixture to be sifted can be separated. The individual transport units are arranged at an angle such that their upper end is higher than their lower end. Each transport unit is assigned a fan, which generates an air flow directed toward the upper end of the respective transport unit.In order to separate a material mixture consisting of a light, a medium, and a heavy fraction, the material mixture is applied to the first transport unit by a feed device and moved upwards by its conveyor belt. The heavy fraction of the material mixture then falls from the upper end of the first transport unit into a collecting container located below it. The remaining portion of the material mixture is transported to the second transport unit by the blower assigned to the first transport unit. Because the second transport unit is arranged at an angle, part of the medium fraction moves downwards due to the effect of gravity, against the effect of the conveyor belt of the second transport unit, and falls into a collecting container located below the lower end of the second transport unit.The remaining portion of the medium fraction, as well as the materials of the light fraction, are moved upwards by the second transport unit. The remaining portion of the medium fraction then falls from the top of the second transport unit into another collection container located below it. The remaining light fraction is transported to the third transport unit by the blower assigned to the second transport unit. The so-called "rollable" portion of the light fraction then falls into a container below the bottom of the transport unit, and the remaining portion of the light fraction is transported to the top of the third transport unit and then falls into a container located below the top of this third transport unit.

[0003] US 2008 / 0105597 A1 describes a device and a method for screening a material mixture, which comprises a feed device that transports the material mixture to be screened to a first transport unit. A second transport unit is provided, which is separated from the first transport unit by a chute, via which a first material or a first group of materials is separated from the material mixture with a first fluid resistance. Following the two-part second transport unit is a third transport unit, which is designed to be permeable to the material.The second and third transport units are arranged overlapping in the transport direction; the rear end of the second transport unit is positioned above the front end of the third transport unit, so that the materials of the material mixture located on the second transport unit fall directly from the second transport unit onto the third transport unit. The third transport unit is, in turn, inclined so that its lower end is lower than its higher end.Through the combination of the effect of gravity, the upward arrangement of the third transport unit and the design, arrangement and movement of discs which are provided in the third transport unit, a separation of the materials of the material mixture applied to the third transport unit is achieved, since the heavier materials of this material mixture roll downwards on the third transport unit due to the effect of gravity and the inclined position of the third transport unit and fall onto a removal device arranged below the lower end of the third transport unit.

[0004] EP 0 392 455 A1 discloses a cleaning machine for granular material based on the air sifting principle: a feed material stream is passed through by an air stream, whereby the feed material stream is divided into two fractions. A first fraction containing the heavier particles falls through to the bottom and can then be further processed. A second fraction containing the lighter particles is entrained by the air stream. For this purpose, a feed chute is provided above a grate, which is charged with the material to be cleaned. The grate is formed by spaced-apart, aerodynamically profiled slats extending across the entire width of the machine. The feed chute opens into a sifting chamber containing the grate and delimited at the top by a flow baffle, in which the first and second fractions of the feed material stream are separated.The floor of the screening chamber is funnel-shaped and has a window open at the bottom through which the first fraction is discharged. The second fraction is discharged through a window arranged diagonally opposite the grate in the area of ​​the screening chamber wall opposite the feed chute. Adjacent to the screening chamber is an expansion chamber accessible via the window, whose funnel-shaped floor is equipped with a discharge lock. In the expansion chamber, the second fraction is separated into two partial streams, with the first partial stream consisting of the heavier particles of the second fraction. This partial stream is discharged via the aforementioned discharge lock. The second partial stream of the second fraction consists of the lighter particles of the same. These are entrained by the air that escapes from the expansion chamber through another window opposite the window.Connected to the additional window is an inlet nozzle of a centrifugal separator arranged with a horizontal axis, extending over the same width as the grate and, accordingly, the screening chamber and the expansion chamber. This centrifugal separator separates the remaining contaminants from the airflow. The air drawn in by a fan and cleaned in the centrifugal separator is returned to the grate below the feed chute. For this purpose, a supply duct runs along the fan-side vent side wall and leads to a distribution box located near the vent front end and extending over the same width as the associated grate.

[0005] CH 677 327 A5 describes a method and device for separating a mixture of substances, as well as an application of the method. This document describes a separation method and a corresponding device, which utilizes not only dynamic forces but also, in particular, the surface pressure between the bodies to be sorted and an inwardly yielding drum. This separation method is based on the fact that heavy bodies, characterized by the surface pressure, sink into the interior of the drum and are ejected at a lower point than lighter parts, which are repelled by the surface of the drum and removed separately. The mixture of substances to be separated is transferred via a feed device directly into a sorting drum. This drum is driven by a shaft to which bristles are attached, which are shaped into a cylindrical form by the tubular shape of the drum and the centrifugal force acting in the process.Due to surface pressure, heavy parts like glass bottles sink into the drum, while light parts like aluminum cans and plastic bottles are immediately rejected upon impact with the sorting drum. These light parts fall onto a discharge belt for light materials and are transported away. The heavier parts that have penetrated the drum are picked up by the bristles and directed to a discharge belt for heavy materials located below the drum. The air flow generated by the drum is used to lift light parts like paper and plastic parts from the drum, and these very light parts are simultaneously vacuumed away via an aspiration system.

[0006] DE 195 01 263 C2 discloses a method and a device for classifying a material mixture consisting of at least two materials or at least two material groups. The device comprises a first blower unit for generating a fluid flow and a transport unit arranged beneath the blower unit, by means of which the material mixture can be transported from the blower unit to a drop section. The drop section is subjected to a further fluid flow passing through the material mixture, wherein the further fluid flow is generated by a second blower unit. It is provided that a dissipation unit is arranged between the first blower unit and the second blower unit, which dissipates the first air flow flowing into it, wherein this dissipation unit is designed as a channel unit and the first fluid flow can flow out of a channel of the channel unit.This ensures that the first fluid flow is at least partially attenuated after passing through the material mixture by being at least partially dissipated by the dissipation unit before reaching the second fluid flow. The known method provides for the material mixture to be introduced into a first fluid flow generated by a suction fan, such that at least a defined portion of the material or group of materials with lower fluid resistance is spatially separated from the remaining portion of the material mixture. The material mixture thus separated is conveyed by a transport unit running beneath the fan unit to a drop section, said drop section being subjected to a further fluid flow passing through the material mixture.This creates a combined pressure-suction process which is particularly suitable for wind sifting of recycling material in waste management.

[0007] DE 10 2005 008 210 B4 discloses a device for classifying a material mixture consisting of at least two materials or at least two material groups, as well as a method of this kind. The device comprises a suction fan unit for generating a fluid flow and a first transport device arranged below the suction fan unit, by means of which the material mixture can be transported from the suction fan unit to a drop section. The drop section is subjected to a further fluid flow passing through the material mixture, this further fluid flow being generated by the suction fan unit arranged above the first transport unit. It is also essential that the device comprises a shield by means of which the fluid supply to the suction fan unit, which generates the further fluid flow, is reduced or at least limited from outside the drop section.

[0008] EP 2 366 461 B1 discloses an air classifier having a first conveyor element which conveys a waste mixture to a classifying drum, wherein this waste mixture can be discharged onto the outside of the classifying drum. A blowing device is arranged between the first conveyor element and the classifying drum, the air flow of which is directed from below towards the area of ​​the classifying drum onto which the waste mixture impinges. The direction of rotation of the classifying drum coincides with the blowing direction of the air flow where the air flow impinges on the periphery of the classifying drum. A distribution device is provided between the first conveyor element and the classifying drum, which has at least one horizontally arranged, rotationally driven plate, wherein the distribution device is designed such that it distributes the portions of the waste mixture impinging on the first conveyor element over a greater width than the portions of the waste mixture impinging on the first conveyor element.The waste mixture distributed in this way is distributed onto a second conveyor element, from which it is transferred to the screening drum. The distance between the aforementioned second conveyor element and the screening drum, as well as its running speed, are adjusted to suit the waste material in such a way that the waste mixture hits the screening drum in the upper quadrant of the side facing the second conveyor element, i.e., on the circumference of the screening drum, which is located between its uppermost point, i.e., the zenith, and the point furthest from the second conveyor element, i.e., its equator. According to one embodiment of the device described in the aforementioned publication, a belt, designed as a conveyor belt, rests on the surface of the screening drum, so that the screening drum essentially forms a deflection pulley for this conveyor belt.In this way, the lighter components of the waste mixture that have passed the zenith of the screening drum can also be transported to a location relatively far from the screening drum. To avoid this undesirable effect, known from the aforementioned publication, it is proposed that an impact element be inserted into the waste mixture's flight path. This impact element is designed as an impact curtain, impact roller, or guide plate, which deflects the waste components impacting the impact element and guides them toward the aforementioned peripheral section of the screening drum.

[0009] EP 2 486 986 B1 discloses a distribution device for an air sifter, which can be arranged between a first conveyor element, which carries a waste mixture, and a downstream device onto which the waste mixture is to be fed. The distribution device has at least one horizontally arranged, rotationally driven turntable and is designed such that it distributes the portions of the waste mixture impinging on the first conveyor element over a greater width than they occupy on the first conveyor element.The distribution device has two horizontally arranged, counter-rotating turntables which distribute impinging portions of the waste mixture forwards in the conveying direction of the first wind conveyor element and laterally outwards, wherein the turntables are arranged at different heights and a first turntable extends partially over the second turntable and the turntables are each shaped in a trough-like concave manner.

[0010] All of the aforementioned devices and methods for air separation of a material mixture allow the separation of a material mixture into two groups, namely a heavier first group of materials and a lighter second group of materials, which contains the remainder of the introduced material mixture remaining after the separation described above, i.e., the portion that was not previously separated from the material mixture by gravity using the known device. However, there is a growing need, particularly in waste management, to separate an introduced material mixture into more than two different material groups.

[0011] It is therefore an object of the present invention to further develop a device and a method of the type mentioned at the outset in such a way that a mixture of materials can be divided into at least three material groups in a simple manner.

[0012] To achieve this object, the device according to the invention proposes that the device has at least one third transport unit following the second transport unit in the transport direction of the material mixture and arranged at a distance from the latter, that a second chute is provided between the second and the third transport unit, through which chute at least the second material or the second group of materials is separated from the material mixture with a second fluid resistance, and that a transit route for the materials or material mixtures is formed between the second transport unit and the third transport unit, via which transit route the remaining materials or material mixtures are transported to the third transport unit, and that the third transport unit is designed to be permeable to material and / or permeable to a fluid flow.

[0013] The method according to the invention provides that at least one further material or a further group of materials is screened by a second chute following in the transport direction of the second transport unit, and that the remaining materials or material mixtures are transported via a transit route to a third transport unit designed to be permeable to material and / or permeable to a fluid flow and are screened in this third transport unit.

[0014] The measures according to the invention advantageously provide a device for screening a mixture of materials, which is characterized by a simple structure and efficient operation.By providing according to the invention that the device according to the invention has at least one third transport unit following the second transport unit in the transport direction of the material mixture, wherein a transit route is formed between the second transport unit and the third transport unit for the materials or groups of materials of the material mixture which were not previously discharged through the first chute, and furthermore that a second chute is provided through which at least the second material or the second group of materials can be separated from the material mixture, and that the third transport unit is permeable to material and / or permeable to a fluid flow, an efficient separation of the material mixture is achieved.

[0015] According to an advantageous development of the invention, a removal device for the fourth material or the fourth group of materials is provided above the third transport unit. This device preferably has at least one removal channel through which a third fluid stream, generated by a suction fan, flows. This advantageously achieves efficient suction of the fourth material or the fourth group of materials.

[0016] A further advantageous development of the invention, which is of independent protection-justifying significance, consists in the fact that the device according to the invention provides that the aforementioned third fluid stream runs through the third transport unit and through the transit route between the second and third transport units. Such a measure has the advantage that not only can the fourth material or fourth group of materials located on the third transport unit be transported away by the removal device, but that the fourth material or fourth group of materials can also be entrained by the third fluid stream running through the transit route during its journey from the second to the third transport unit.

[0017] Such a measure is particularly advantageous if, according to a further advantageous development of the invention, which in turn has an independent protection-founding significance, it is provided that the transit route between the second and the third transport unit is acted upon by a fluid flow which flows at least partially through the second drop shaft and thus the transit route and which is introduced into the second drop shaft against the effect of gravity.Such a measure has the advantage that the fourth material or the fourth group of materials, which are more strongly influenced by a fluid flow than the other materials, differs from the other materials in terms of trajectory, i.e. the trajectory of the pieces of the fourth material or the fourth group of materials is higher than that of the other materials, so that the fourth material or the fourth group of materials then comes to lie on the third transport unit above the other materials and is thus easier to transport away.

[0018] A further advantageous development of the invention provides that the first transport unit and / or the second transport unit are arranged in the device at a variable distance from the subsequent transport unit and / or with a variable inclination. Such a measure has the advantage that the ejection behavior of the respective transport unit can be easily adjusted by positioning one transport unit relative to the other transport unit in conjunction with the appropriate selection of the transport speed of this transport unit.

[0019] According to the invention, the device comprises a dissipation device for the first fluid stream, the dissipation device comprises an adjustable, in particular openable and closable, flap, and when the flap is at least partially open, the suction fan of the removal device can generate a fluid stream passing through the flap. Such a measure has the advantage that the suction fan of the removal device can already suction off the fourth material at the end of the second transport unit.

[0020] Further advantageous developments of the invention are the subject of the subclaims.

[0021] Further details and advantages of the invention can be found in the exemplary embodiment described below with reference to the drawings. Figure 1 shows a first embodiment of a device for classifying a mixture of materials, Figure 2 shows a second embodiment of a device for classifying a mixture of materials, Figure 3 shows a third embodiment of a device for classifying a mixture of materials, Figure 4 shows a fourth embodiment of a device for classifying a mixture of materials, and Figure 5 shows a fifth embodiment of a device for classifying a mixture of materials.

[0022] In Figure 11 shows a first exemplary embodiment of a device for sifting a material mixture M. This device is essentially divided into a feed station 2, a first transport unit 10, a second transport unit 20, above which a dissipation device 40 is arranged, and a third transport unit 30. The second transport unit 20 is arranged downstream of the first transport unit 10 in the transport direction of the material mixture M to be sifted and at a distance from it. In a corresponding manner, the third transport unit 30 is arranged downstream of the second transport unit 20 in the transport direction of the material mixture M to be sifted and is in turn spaced from it. Each of these transport units 10, 20, 30 moves the material mixture M lying on it in the transport direction of the device 1, i.e. from left to right in the representations of the figures.A first chute 100a with a first drop distance is formed between the first transport unit 10 and the second transport unit 20, and a second chute 100b with a second drop distance is formed between the second transport unit 20 and the third transport unit 30. A first blower unit 50 is provided between the two aforementioned transport units 10 and 20, generating a fluid flow S1, in particular an air flow, which is introduced into the first chute 100a and flows from bottom to top, i.e., opposite to the direction of gravity, through the chute 100a or at least a region thereof.In a corresponding manner, a second blower unit 60 is arranged between the second transport unit 20 and the third transport unit 30. This second blower unit generates a second fluid flow S2, in particular an air flow, which is introduced into the second chute 100b and flows through it from bottom to top, i.e., against the direction of gravity, at least in a partial area. The mechanical design of the aforementioned components of the device 1 is known; therefore, it does not need to be described in more detail, and it is sufficient to describe it in . Figure 1 and the following figures only show these components schematically.

[0023] The material mixture M to be screened by the device 1 contains at least three materials M1, M2, and M3 or at least three material groups. In the exemplary embodiment described here, it is provided by way of example that the material mixture contains four materials M1, M2, M3, and M4 or four material groups. It will be apparent to those skilled in the art from the following description that this does not limit the generality of the following considerations. The device 1 described and the method explained with reference to the device 1 can also be used to screen a material mixture consisting of only three materials or three material groups, or more than four materials or four material groups.

[0024] It is assumed that the first material M1 or the first group of materials has a lower first fluid resistance than the second material M2 or the second group of materials, which has a second fluid resistance. The third material M3 or the third group of materials has a third fluid resistance that is greater than or equal to the second fluid resistance. The fourth material M4 or the fourth group of materials has a fourth fluid resistance that is greater than the first three fluid resistances. As an example of such a mixture of materials, a constellation that occurs particularly frequently in waste management should be mentioned, in which the first material or the first group of materials, for example, stones and / or mineral construction waste, the second material or the second group of materials and the third material or the third group of materials, for example, wood parts, e.g. medium grain wood orWood oversize, and the fourth material or the fourth group of materials are, for example, leaves or films, in particular plastic films. It will be apparent to those skilled in the art from the following description that the aforementioned materials are merely exemplary in nature, and the device 1 and the method for air-classifying a mixture of materials described below using this device are not limited to the aforementioned materials.

[0025] For the sake of a more concise description, we will refer only to a material M1-M4 in the following, although the term "material" is also intended to encompass a "material group." For clarification, it should also be noted that "low fluid resistance" means that a certain material is less affected by a fluid flow than a material with a higher fluid resistance, for example, because it is heavier than the material with a higher fluid resistance and / or offers a smaller surface area for the fluid flow to attack, thus being more compact.

[0026] The material mixture M is fed into the device 1 via the feed station 2 and falls from there onto the first transport unit 10. Preferably, a distribution station (not shown) can be arranged in this area, which causes the material mixture M falling from the feed station 2 onto the first transport unit 10 to be distributed across its width. Preferably, the first transport unit 10 is designed as a circulating conveyor belt with deflection rollers 11a, 11b and a conveyor belt 12, the first end 10a of which faces the feed station 2 and the second end 10b of which is adjacent to a first end 20a of the second transport unit 20.

[0027] The first transport unit 10 moves the material mixture M located thereon toward the second transport unit 20, wherein—as already described above—the first chute 100a with the first drop distance is provided between the first transport unit 10 and the second transport unit 20. This chute 100a is formed by providing a free space between the second end 10b of the first transport unit 10 and the adjacent first end 20a of the second transport unit 20, so that a portion of the material mixture M—here the first material M1—can fall downward through this free space and thus out of the device 1.

[0028] The first transport unit 10 serves as an acceleration station for the material mixture M located thereon, so that - as described below - the first material M1 falls out of the device 1 through the first drop section with the first fluid resistance, while the remaining portion of the material mixture M to be separated - preferably with the aid of the first fluid stream S1, as described below - is transported to the second transport unit 20 via the drop shaft 100a separating the two transport units 10, 20.

[0029] Preferably, the first transport unit 10 is arranged in the device 1 so that its position can be changed relative to the second transport unit 20, so that the distance between the second end 10b of the first transport unit 10 and the first end 20a of the second transport unit 20, and thus the length of the chute 100a between the two transport units 10, 20, as seen in the transport direction of the material mixture, can be reduced or increased. This is preferably achieved by the first transport unit 10 being arranged in the device 1 so that it can be displaced in the transport direction of the material mixture. However, it is also possible for the second transport unit 20 to be arranged in the device 1 so that its position can be changed, in particular displaced, in order to change the distance between the two transport units 10, 20, although a combination of the two aforementioned measures is also possible.

[0030] It is further preferred that the first transport unit 10 is also variable in its inclination.

[0031] By changing the distance between the first transport unit 10 and the second transport unit 20 and / or changing the inclination of the first transport unit 10, in conjunction with a suitable selection of the transport speed of the first transport unit 10, the trajectories of the materials M1-M4 of the material mixture to be screened can be selected such that the - generally heavier - first material M1 does not reach the second transport unit 20, but falls through the chute 100a, while the remaining portion M2-M4 of the material mixture M, i.e. the second, third and fourth materials M2-M4, are transported to the second transport unit 20.

[0032] As in Figure 1As shown schematically, it is preferably provided that the first fluid flow S1 generated by the blower unit 50, usually an air flow, is introduced into the first chute 100a, which passes through the chute 100a between the first and second transport units 10 and 20 from bottom to top, thus pressurizing the portion of the material mixture M located above the chute 100a. The trajectory of the second material M2 and the third and fourth materials M3 and M4 is thereby increased, with the result that the three aforementioned materials M2-M4 are moved to the second transport unit 20, while the first material M1 falls through the chute 100a and can thus be sorted out from the material mixture M.

[0033] It is self-evident to a person skilled in the art that the transport speed, the inclination and / or the distance between the first transport unit 10 and the second transport unit 20, i.e. the length of the chute 100a, is adapted to the effect of the first fluid stream S1 in such a way that the above-described separation of the first material M from the remaining part of the material mixture M to be screened is achieved. In principle, it is possible to carry out this separation solely by the first transport unit 10, which serves as an acceleration station for the material mixture. However, the use of the blower unit 50 to generate the first fluid stream S1 has the advantage, in addition to the above measures and effects, that it also facilitates the screening of the remaining part of the material mixture M, as described in more detail below.

[0034] In the above description, it was assumed that the first material M1 falls essentially directly from the first transport unit 10 into the first chute 100a and the further materials M2-M4 reach the second transport unit 20. However, this presupposes that the individual materials M1-M4 of the material mixture M to be screened have been accelerated to such an extent by the first transport unit 10, which serves as an acceleration station for this material mixture M, that the first material M1 falls into the first chute 100a and the further materials M2-M4 - preferably with the assistance of the air stream S1 - reach the second transport unit 20. This can be accomplished relatively easily if there are large differences in fluid resistance between the first material M1 and the further materials M2-M4, e.g.when the first material M1 is significantly heavier than the other materials M2-M4, so that they can be accelerated sufficiently to bridge the distance between the end 10b of the first transport unit 10 and the beginning of the second transport unit 20. Often, however, the differences between the first material M1 and the other materials M2-M4 are not so great that the separation described above can be achieved to a sufficient extent. Therefore, a greater acceleration of the materials M1 and M2-M4 is often necessary, with the result that a more or less large proportion of the first material M1 does not fall directly into the chute 100a, but impacts the first end 20a of the second transport unit 20.It is therefore preferred that the first end 20a of the second transport unit 20 is designed as a type of impact unit for the first material M1, which causes the first material M1 striking the initial region of the second transport unit 20 to be directed to the first chute 100a.

[0035] The second transport unit 20 is in turn preferably designed as a conveyor belt having two deflection rollers 21a, 21b and a revolving conveyor belt 22. Preferably, the conveyor belt 22 is made of a resilient material. This has, among other advantages, that pieces of the first material M1 that impact the upper quadrant of the deflection roller 21a facing the first transport unit 10 bounce farther off this deflection roller 21a due to the resilient properties of the conveyor belt 22 than would be the case if these pieces of material impacted a hard surface. The conveyor belt 22 running over the first deflection roller 21a thus serves as the impact element for the first material M1 mentioned in the previous paragraph.

[0036] In the aforementioned embodiment of the second transport unit 20 as a circulating conveyor belt, it is preferred that the trajectory of the second and third material or the second and third material group is selected such that these material particles are moved over the zenith of the deflection roller 21a.

[0037] As from Figure 1 As can be seen, it is preferred that the first deflection roller 21a facing the first transport unit 10 is larger than the second deflection roller 21b, it therefore has a larger impact surface for the first material M1, and consequently forms a larger impact element.

[0038] The second transport unit 20 now transports the portion of the material mixture M remaining after the aforementioned separation step in the direction of the third transport unit 30. In the simplest embodiment of the device 1, the separation of the second material M2 from the further materials M3 and M4 of the material mixture M is again carried out as described above, namely that the material mixture M remaining on the second transport unit 20 is accelerated in such a way that the second material M2 - corresponding to the first material M1 - falls through the second chute 100b, while the third and fourth materials M3 and M4 overcome the second chute 100b and finally reach this third transport unit 30 via a transit route 101 between the second and third transport units 20 and 30.The statements made regarding the design, function, and effect of the first transport unit 10, the second transport unit 20, and / or the first blower unit 50, particularly regarding the positioning, changing the inclination of the second transport unit 20, and / or the selection of the transport speed, apply accordingly. Here, too, it is fundamentally possible—as with the separation of the first material M1—to dispense with the second blower unit 60 and thus the second fluid stream S2. However, here, too, the use of a second fluid stream S2 offers the advantages described below.

[0039] In the above-described assumption—the simplest embodiment of device 1—the materials M3 and M4 are then transported further by the third transport unit 30 and then fall into a third chute 100c at its end 30b. Device 1 in its simplest embodiment described above thus allows the separation of a material mixture M containing three materials M1-M3.

[0040] In Figure 1However, a more complex embodiment of the device 1 is shown, which is described below: As can be seen from the aforementioned figure, the device 1 is designed such that the second chute 100b and thus the second fall section do not run between the second and the third transport unit 20 and 30, but it is provided that the second chute 100b and thus the second fall section runs through the third transport unit 30, so that the second material M2 falls through the third transport unit 30 and the third material M3 is transported further by the third transport unit 30 and falls at the end 30b into the third chute 100c. This can preferably be achieved in that the third transport unit 30 is designed as a sieve, such that this sieve is permeable to the second material M2, but not to the third material M3.The third transport unit 30 can preferably be designed as a star or disc sieve.

[0041] The above-described embodiment of the device 1 thus allows a material mixture M consisting of three materials M1-M3 to be screened in a simple manner. However, as already mentioned at the beginning, it is assumed here that the material mixture M to be screened comprises not just three, but four materials M1-M4. In order to be able to screen the material M4 as well, i.e. to be able to screen the mixture of the materials M3 and M4 remaining on the third transport unit 30 after the separation of the second material M2, it is preferably provided that the fourth material M4, while it passes through the transit section 101, is subjected to the second fluid stream S2 generated by the second blower unit 60 in such a way that this material M4 is entrained by the second fluid stream S2 and transported to a fourth chute 100d.Preferably, a separating element 90 is provided between the third chute 100c and the fourth chute 100d, which at least reduces, if not prevents, the fourth material M4 from falling into the third chute 100c and thus the mixing of the materials M3 and M4.

[0042] In Figure 2A second embodiment of the device 1 is shown, which corresponds in its basic structure to that of the first embodiment, so that corresponding components with regard to their design, arrangement, function and effect will not be described in more detail. The essential difference between the first and second embodiment is that for the separation of the fourth material M4, a removal device 70 is provided which is arranged above the third transport unit 30 and which serves to remove the material M4 located on the surface of the third transport unit 30. In the embodiment described here, the removal device 70 is designed as a suction device which has a Figure 2has a suction fan 71, shown only schematically, which generates a suction flow S3. In the case described here, the removal device 70 has a cover 72, which is arranged above the third transport unit 30 and serves to prevent or at least reduce the inflow of ambient air, so that the material M4 located on the third transport unit 30 can be sucked in by the removal device 70 and thus removed from the device 1. The suction is thus effected by the negative pressure generated by the suction fan 71 on the transport unit 30.

[0043] It was described above that it is preferred that the third transport unit 30 is permeable to the second material M2, i.e. that the second material M2 falls through this third transport unit 30, which is designed to be permeable to the material, into the second chute 100b. In the second exemplary embodiment, it is preferred that the removal device 70 is designed such that the third fluid stream S3 runs through the third transport unit 30 and - as fluid stream S‴preferably through the transit section 101, i.e. the suction fan 71 of the removal device 70 sucks the fluid stream S3 through the third transport unit 30 and preferably through the transit section 101. This has the effect that the material M4 lying on the third transport unit 30 and the material M4 passing through the transit section 101 are entrained by this third fluid stream S3 and thus transported away.In the second embodiment, the third transport unit 30 is both material-permeable and fluid-flow-permeable, i.e., generally air-permeable.

[0044] The above-described material-permeable design of the third transport unit 30, as is particularly the case with a star or disc screen, is not absolutely necessary. For a variety of applications, it may be sufficient for the third transport unit 30, as described above, to be only permeable to fluid flow, i.e., generally permeable to air. This is particularly advantageous when the material mixture M to be separated contains only materials M1, M2, M3, and M4, with the fourth material M4 being sucked off by the removal device 70 as described above. The second and third materials M2 and M3 are then guided from the second end 30b of the third transport unit 30 into the third drop shaft 100c, which then corresponds functionally to the second drop shaft 100b.

[0045] In the aforementioned configuration, the use of the second blower unit 60 and the second fluid stream S2 generated by it is advantageous: If the material mixture falling from the second end 20b of the second transport unit 20 to the first end 30a of the third transport unit 30 through the transit path 101, i.e. a mixture of the materials M2-M4, is impinged upon by the second fluid stream S2, this has the effect that in particular the trajectory of the particles of the fourth material M4, i.e. the material most strongly influenced by exposure to a fluid stream, is higher than the trajectories of the materials M2 and M3. This has the consequence that the fourth material M4 lies on the materials M2 and M3 on the third transport unit 30 and can thus be more easily sucked away by the removal device 70.

[0046] As already explained above, in the first and second exemplary embodiments, a dissipation device 40 is preferably arranged above the second transport unit 20. This dissipation device serves to dissipate the first fluid flow S1 generated by the first blower unit 50, so that it does not reach the removal device 70, or at least only in a weakened form. This has the advantage that the suction fan 71 of the removal device 70 largely only has to suck up the third fluid flow S3, S3' flowing through the third transport unit 30 and possibly the fluid flow S‴ flowing through the transit section 101, which - as described above - serves to remove the fourth material M4. The first fluid flow S1, which does not contribute to this, therefore does not have to be removed by the removal device 70. This is advantageous for reasons of efficient operation of the removal device 70.It is therefore preferred that the device 1 be designed in such a way that the first fluid stream S1 reaches the third transport unit 30 as little as possible, with the result that it does not need to be sucked away by the third transport unit 30. As already mentioned above, the dissipation device 40 serves this purpose in particular. However, it is also possible that, instead of or in addition to this, guide devices are provided in the device 1, which attenuate or divert the first fluid stream S1 before it reaches the removal device 70.

[0047] For the aforementioned reason, it is advantageous that only a small free space remains between the second transport unit 20 and the rear end 40b of the dissipation device 40 in the conveying direction, functioning as a transport gap 42, through which the materials M2, M3, and M4 transported by the second transport unit 20 are moved out of the dissipation device 40. In order to ensure that even larger pieces of the materials M2-M4 are not hindered during their removal, it is preferably provided that the dissipation device 40 has a movable flap 41 at its end 40b, which swings out when larger pieces of the materials M2-M4 pass through. After such a passage, the flap 41 returns to its starting position and - as described above - closes the transport gap 42 between the dissipation device 40 and the second transport unit 20 again to a corresponding extent.

[0048] According to a preferred embodiment of the dissipation device 40, the flap 41 is adjustable, in particular, can be opened and closed in a controlled manner. Since—as described above—the lighter material M4 has a higher trajectory, it lies on the materials M2 and M3 at the end of the dissipation device 40, is therefore not covered by these materials, and can therefore be efficiently sucked away by means of a suction flow S4 generated by the suction fan 71 or 71a of the removal device 70. By now providing for the flap 41 to be selectively adjusted, the suction fan 71 or 71a of the removal device 70 can suck away this fourth material M4 by means of the fluid flow S4 already at the end of the second transport unit 20.By preferably providing that the flap 41 is constructed in such a way that the opening of the transport gap 42 can be variably adjusted, the flow behavior of the materials M2-M4 and in particular of the fourth material M4 can be influenced in an advantageous manner.

[0049] It is then preferred that - as shown in the figures - the front end 70a of the removal device 70 in the transport direction is arranged above the second end 20b of the second transport unit 20, that is to say that in particular the suction channel 73, 73a is arranged above the transit path 101 between the second and the third transport unit 20 and 30.

[0050] It will be apparent to those skilled in the art from the above description that the dissipation device 40 is consequently not required if - as also already explained - according to a non-preferred embodiment of the device 1, the use of a first fluid stream S1 and thus the first blower unit 50 is dispensed with or the fluid stream S1 is designed such that it does not influence, or only insignificantly influences, the operation of the removal device 70. In this case, the second transport unit 20 is preferably not absolutely necessary; rather, it can be provided that the first chute 100a is formed between the first and third transport units 10 and 30, so that the materials M2-M4 are transferred from the first transport unit 10 to the third transport unit 30 as described above and the material M1 falls through the chute 100a.

[0051] As already mentioned above, the use of the first fluid stream S1 not only has the advantage of making the transfer of the materials M2-M4 of the material mixture M from the first to the second transport unit 10 and 20 or from the first transport unit 10 to the third transport unit 30 (if the dissipation device 40 is omitted) more efficient. Just as described above for the second fluid stream S2, the impingement of the material mixture M by the first fluid stream S1 also causes the individual materials M1-M4 to exhibit different trajectories due to their different fluid resistance. Material M1 is least affected by the fluid stream S1, and thus falls through the first chute 100a. Material M4 is most strongly affected by the fluid stream S1, and the trajectory of the pieces of material M4 is therefore generally higher, as shown in the Figure 1 and 2This is indicated by showing pieces of the fourth material M4 in the area of ​​the dissipation device 40. This then results in the pieces of material M4 lying on the second transport unit 20 on top of the materials M2 and M3, so that the material M4 can be more easily sucked off. Preferably, a dissipation unit 40 is used, as described in the applicant's DE 195 01 263 C2.

[0052] In Figure 3A third embodiment of a device 1 is shown, which corresponds in its basic structure to that of the second embodiment, so that corresponding components are provided with the same reference numerals and their design, function, and / or effect will not be explained in more detail. The essential difference between the first and second embodiments is that the removal device 70 now has two removal channels 73a and 73b, with a suction fan 71a, 71b arranged in each of these removal channels 73a, 73b.

[0053] The suction fans 71a and 71b generate fluid flows S3' and S3", which suck the fourth material M4 from the surface of the third transport unit 30. At least the first of the fluid flows S3' and S3" runs through the third transport unit 30 and, as fluid flow S3‴, preferably through the transit path 101, as described in the second and third exemplary embodiments. The offset arrangement of two removal channels 73a and 73b in the transport direction has the advantage of providing improved suction of the fourth material M4, since the suction is now no longer only in an area in which the fourth material M4 is still acted upon by the second fluid flow S2 and is thus suspended, but is also sucked into the second removal channel 73b by the fluid flow S3' generated by the second suction fan 71b.

[0054] In the Figure 4 and 5A fourth and a fifth exemplary embodiment are shown, wherein the basic structure of the fourth and fifth exemplary embodiments corresponds to that of the second and third exemplary embodiments, respectively, so that corresponding components are again provided with the same reference numerals and their design, configuration, function, and effect will not be described in more detail. The essential difference between the corresponding exemplary embodiments is that—as already outlined in the description of the first and second exemplary embodiments—the second blower unit 60 is omitted in the fourth and fifth exemplary embodiments.

[0055] In summary, it can be stated that the described device 1 is characterized in that it enables the separation of a material mixture M consisting of at least three materials M1-M4 in a simple manner and in an efficient manner.

Claims

1. Device for screening a materials mixture (M) consisting of several materials (M1-M4) or groups of materials, the device (1) comprising a first transport unit (10) to which the materials mixture (M) can be fed by a feed device (2), and a second transport unit (20), which is arranged downstream in a transport direction of the materials mixture (M) and at a distance from the first transport unit (10), and a first chute (100a) being provided between the first transport unit (10) and the second transport unit (20), via which a first material (M1) or a first group of materials with a first fluid resistance can be separated from the materials mixture (M), wherein the device (1) comprises at least one third transport unit (30 ) being arranged downstream in the transport direction of the materials mixture (M) and at a distance from the second transport unit (20), wherein between the second and the third transport unit (20, 30) a second chute (100b) is provided, by which at least the second material (M2) or the second group of materials having a second fluid resistance can be separated from the materials mixture (M), and wherein the second chute (100b) extends between the second transport unit (20) and the third transport unit (30) or passes the third transport unit (30), wherein the third transport unit (30) is material-permeable and / or permeable for a fluid current (S3; S3', S3"), characterized in that the device (1) comprises a dissipation device (40) by which a first fluid current (S1) can be dissipated, and that the dissipation device (40) comprises an adjustable flap (41), in particular one that can be opened and closed, and that, when the flap (41) of the dissipation device (40) is at least partially open, a fluid current (S4) running through the flap (41) can be generated by a suction fan (71; 71a, 71b) of the removal device (70).

2. Device according to claim 1, characterized in that the removal device (70) for a fourth material (M4) or a fourth group of materials having a fourth fluid resistance is arranged above the third transport unit (30).

3. Device according to claim 2, characterized in that the removal device (70) for the fourth material (M4) or the fourth group of materials has at least one removal channel (73; 73a, 73b), through which a third fluid current (S3; S3', S3") flows, and that the third fluid current (S3; S3', S3"; S3‴) is generated by at least one suction fan (71; 71a, 71b) arranged above the third transport unit (30).

4. Device according to one of the preceding claims, characterized in that the third fluid current (S3; S3', S3"; S3‴) flows through the third transport unit (30) and through the passage (101) between the second and third transport unit (20, 30).

5. Device according to one of the preceding claims, characterized in that at least one blower unit (50, 60) is provided between the first transport unit (10) and the second transport unit (20) and / or the third transport unit (30), through which a first fluid current (S1) and / or a second fluid current (S2) can be generated, and that the first fluid current (S1) and / or the second fluid current (S2) is led into the first chute (100a) and / or into the second chute (100b) against the effect of gravity.

6. Device according to one of the preceding claims, characterized in that downstream of the third transport unit (30) a third chute (100c) is provided, through which at least one further material (M3, M4) or at least one further group of materials can be separated from the remaining materials mixture.

7. Device according to one of the preceding claims, characterized in that the first transport unit (10) and / or the second transport unit (20) are arranged in the device (1) variably and / or inclination variably in terms of the transport unit (20 and 30 respectively) being arranged downstream thereof.

8. Method for screening a materials mixture (M) comprising several materials (M1 - M4) or material groups, in which the materials mixture (M) to be screened is transported from a first transport unit (10) to a second transport unit (20) being arranged in a transport direction of the materials mixture (M) downstream of and at a distance to the first transport unit (10) and the first material (M1) or the first group of materials with a first fluid resistance is removed in a first chute (100a) being arranged between the first and the second transport unit (10, 20) and the remaining portion of the materials mixture (M) is fed to the second transport unit (20), wherein at least one further material (M2, M3, M4) or at least one further group of materials is screened in a second chute (100b) being arranged in the transport direction downstream of the second transport unit (20), wherein the second material (M2) or the second group of materials having a second fluid resistance falls from the third transport unit (30) or through the third transport unit (30) out of the device (1), characterized in that a dissipation device (40) is used, in which a first fluid current (S1) can be dissipated, and that, when the flap (41) of the dissipation device (40) is at least partially open, a fluid current (S4) running through the flap (41) can be generated by the suction fan (71; 71a, 71b) of the removal device (70).

9. Method according to claim 8, characterized in that the method is carried out by means of a device (1) according to one of the claims 1 to 7.

10. Use of a device according to one of claims 1 to 7 for screening a materials mixture (M) consisting of at least three materials (M1, M2, M3, M4) or at least three groups of materials.

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