System for analyzing and sorting a piece of material

Abstract

The invention relates to a system for analyzing and sorting a material part, in particular a scrap part made of aluminum, comprising: - a feeding means (110) for transporting the material part (120), - a sorting unit (160) configured to feed the material part (120) to one of two fractions (F1, F2), - a laser device (140) configured to generate a plasma (3) on a surface 7A of the material part (120) with a laser beam (5) propagating along a beam axis (5A), - a spectrometer system (1) configured to perform a spectral analysis of plasma light (3A) emitted by the laser-induced plasma (3) and to generate an output signal corresponding to the result of the spectral analysis, and - a control device (150) configured toto receive the output signal and to operate the sorting unit (160) based on the output signal and a sorting criterion, - wherein the spectrometer system (1) comprises a spectrometer (13) and a detection unit (21) optically connected to the spectrometer (13), - wherein the detection unit (21) comprises a lens (25A, 25B, 25C, 25D) to which a detection cone (35) is assigned, which forms a plasma detection area (39) in an overlap area (37) with the laser beam (5), characterized in that the feeding means (110) comprises three individual feeding units (201, 202, 203) arranged in series in the transport direction (207) of the material part (120), each feeding unit (201, 202, 203) being configured to feed the material part (120) to transport along a feeding surface (204, 205, 206) provided by the respective feeding unit (201, 202, 203), wherein the feeding surfaces (204, 205,206) are each inclined to the horizontal by forming a respective angle of inclination (α1, α2, α3), wherein the angles of inclination (α1, α2, α3) are different.

Description

[0001] The invention relates to a system having the features of the preamble according to claim 1.

[0002] A system for analyzing and sorting a material part is known from EP 3 352 919 B1. This previously known system enables the sorting of material parts, in particular aluminum scrap parts, based on laser-induced plasma spectroscopy, also known as LIBS (laser-induced breakdown spectroscopy). Laser-induced plasma spectroscopy is used to determine the element-specific composition of a material part, i.e., a sample, using a plasma. The plasma is generated on a surface of the material part using high-intensity, focused laser radiation. Light emitted by the plasma is detected and spectrally analyzed to determine the elemental composition of the material part.

[0003] In addition, DE 91 06 292 U discloses a device for sorting waste material, in particular waste glass, according to its colour, comprising a vibrating bar screen, a separating device and an optoelectronic measuring and sorting device.

[0004] WO 90 / 11142 A1 discloses a method and device for sorting waste into different types. The device comprises a first conveyor, a second conveyor, and a third conveyor, as well as unloading means, identification means, recording and control means, and waste separation means.

[0005] According to a system previously known from EP 2 859 963 A1, a device for sorting bulk material, in particular pellets, comprises a vibratory conveyor and a feed device that feeds bulk material to the vibratory conveyor, a first outlet and a second outlet, a detector device, and a sorting device that influences the trajectory of bulk material identified as defective such that it falls into the second outlet, wherein a rotating roller is connected to the end of the vibratory conveyor, onto which roller the bulk material conveyed via the end of the vibratory conveyor arrives and which conveys the bulk material towards the first outlet with a trajectory predetermined by the rotation of the roller. It is proposed there that the at least one vibratory conveyor can comprise a plurality of vibratory conveyors arranged one behind the other in the conveying direction of the bulk material.At least two of the plurality of vibrating conveyors may be arranged at different angles to the horizontal.

[0006] According to the system previously known from EP 3 352 919 B1, material parts to be sorted are fed into a feeder. The feeder can, for example, be vibrating plates that provide a feed surface along which the material parts are moved.

[0007] According to EP 3 352 919 B1, the material pieces to be analyzed and sorted are fed into a chute by means of the feeder. Following gravity, the material pieces slide down the chute and exit via a lower edge of the chute. From there, the material pieces to be analyzed and sorted continue to fall freely through the ambient atmosphere, still subject to the force of gravity. The feeder and the chute serve to separate the material pieces and move them in free fall through a spatially defined drop corridor.

[0008] During free fall, laser-induced plasma spectroscopy is performed for each piece of material leaving the slide. For this purpose, a laser device is provided that is configured to generate a plasma on a surface of a piece of material using a laser beam propagating along a beam axis. Furthermore, a spectrometer system is provided that is configured to perform a spectral analysis of the plasma light emitted by the laser-induced plasma and to generate an output signal corresponding to the result of the spectral analysis.

[0009] This output signal, in combination with a sorting criterion, is then used by a sorting unit to direct the material parts leaving the chute to one of two fractions. For example, an air nozzle can be used as a sorting unit, which is controlled accordingly by the control device. From the stream of material parts leaving the chute, certain material parts can be sorted out under the influence of air pressure. The result is a fraction of sorted-out material parts and a fraction of non-sorted material parts.

[0010] Typically, the known system is used to identify material components of a specific composition and separate them from material components of a different composition. Such separation occurs either because a material component of an undesired composition is identified and rejected by the sorting unit, or because the composition of a material component could not be reliably determined and therefore rejected by the sorting unit. The fraction of rejected material components is therefore composed of material components whose composition is clearly identified as undesirable, on the one hand, and material components whose composition is not clearly identified, on the other.

[0011] Although the system described above has proven itself in everyday practical use, there is room for improvement. In particular, it has been shown that for an effective sorting result, it is crucial to feed the material pieces to be sorted to the laser device and / or the spectrometer system individually, thus enabling optimized access by the laser device and / or the spectrometer system during the further course of the process. Otherwise, the sorting result will be adversely affected, with the disadvantageous rejection of material pieces that have not been clearly identified.

[0012] Therefore, based on the above-described state of the art, Task The invention is to further develop a system of the type mentioned at the outset in such a way that increased sorting efficiency is achieved.

[0013] To SolutionTo achieve this object, a system according to claim 1 is proposed.

[0014] According to EP 3 352 919 B1, a feeder is used to transport the material part. This feeder provides a feed surface along which the material part is moved during its intended use. The feeder can be designed, for example, as a vibrating plate. It serves, in particular, to separate a plurality of material parts placed on the feeder so that they can subsequently be fed to the laser device and / or the spectrometer system at a distance from one another.

[0015] However, the separation achieved with the feeding means known from EP 3 352 919 B1 is limited, which means that only a comparatively low throughput is possible.

[0016] The throughput cannot be increased by adding more material to the feeder to be sorted, as this would result in insufficient separation, resulting in a reduction in sorting quality and thus in sorting efficiency. The inventive design provides a remedy for this.

[0017] The feeding means has at least three feeding units. Each of these is designed as an independent assembly. Thus, at least three separate, i.e., individual, feeding units are provided. These are arranged in series one behind the other in the transport direction of the material part, thus providing a first feeding unit in the transport direction, a second feeding unit in the transport direction, and a third feeding unit in the transport direction. These feeding units together form the feeding means according to the invention.

[0018] Each of the feed units is designed to transport the material part along a feed surface provided by the respective feed unit. Each feed unit therefore provides a feed surface. When used as intended, the material part is conveyed in the transport direction and passed from feed unit to feed unit.

[0019] The feed surfaces of the feed units are each inclined to the horizontal, forming a respective angle of inclination. The feed units, or rather their feed surfaces, are thus inclined to the horizontal in such a way that a material part is supported during its transport in the transport direction due to the effect of gravity.

[0020] The feed units each provide, for example, a vibrating plate that provides the respective feed surface. As a result of the vibrating movement of such a plate, a material part located thereon is transported in the transport direction. The inclined orientation of the respective feed surfaces provided according to the invention supports this transport, since the force of gravity acting on the material part is added to the vibrating movement.

[0021] In this context, it is also intended that the inclination angles of the feed surfaces be designed at different sizes. As a result, the different inclination angles result in the force of gravity acting on the material part having a different influence on the transport of the material part in the transport direction, depending on the feed unit. The greater the inclination angle, the greater the influence.

[0022] The different inclination angle configurations advantageously ensure that a material part is accelerated to different degrees in the transport direction depending on the feed unit. This, in turn, advantageously allows for much more efficient separation of multiple material parts, even when there is a large number of material parts to be separated. This is because the different inclinations of the feed surfaces of the individual feed units ensure that the transport speed of the material parts increases with increasing transport distance, which also increases the separation as the transport distance increases. Consequently, separated material parts can be reliably fed to the laser device and / or the spectrometer system, even when there are more material parts to be separated than in the prior art.Thus, the feed means according to the invention ensures an increased flow rate, while at the same time increasing the sorting quality, whereby the sorting efficiency of the system according to the invention is increased overall in contrast to the prior art.

[0023] According to the invention, the angle of inclination of the feed surface of the first feed unit in the transport direction of the material part is smaller than the angle of inclination of the feed surface of the second feed unit in the transport direction of the material part. Due to gravity, the material part is thus accelerated to a higher transport speed by means of the second feed unit. This leads to the separation of the material parts, particularly in the longitudinal direction of the feed unit, i.e., in the transport direction of the material part.

[0024] The comparatively low transport speed achieved by the first feed unit serves in particular to separate the fed material pieces in the width direction of the feed unit, i.e. transversely to the transport direction of the material piece. This measure ensures that the fed material pieces are evened out in the width direction so that the sorting devices that the material pieces have to pass through in the further process step can be served equally. This advantageously prevents individual sorting units from being fed with too many material pieces to achieve a desired sorting quality, while other sorting units provide unused processing capacity. The first feed unit therefore serves to distribute the material pieces across the total available width of the feed means.

[0025] The comparatively low speed of the material parts in the transport direction, which is provided by the first feed unit for the purpose of distributing the material parts across the width, causes a certain buildup of the material parts in the transport direction. This buildup is resolved after the material parts are transferred from the first feed unit to the second feed unit, since, according to the invention, the second feed unit is positioned at a greater angle of inclination than the first feed unit. This results in the material parts fed to the second feed unit being separated longitudinally, i.e., in the transport direction of the material parts.

[0026] According to the invention, it is also provided that the angle of inclination of the feed surface of the second feed unit in the transport direction of the material part is smaller than the angle of inclination of the feed surface of the third feed unit in the transport direction of the material part.

[0027] Due to the even steeper incline of the third feed unit compared to the second feed unit, the material pieces are further accelerated in the transport direction. The material pieces that have already been pre-separated in the transport direction by the second feed unit are now pulled apart even further in the transport direction by the third feed unit, and thus separated. This second separation stage in the longitudinal direction enables a higher number of material pieces to be processed by the feed device compared to the prior art. The first feed unit separates the pieces in the width direction, and the two further feed units each separate them in the length direction, with the result that separated material pieces are fed to the laser device or spectrometer system on the output side across the entire width of the feed device in the length direction.This also enables spectroscopy to be carried out as intended, in contrast to the state of the art at an increased flow rate.

[0028] According to a further feature of the invention, the difference between the angles of inclination is 2° to 8°, preferably 3° to 7°, most preferably 5°.

[0029] As studies have shown, the individual angles of inclination cannot be chosen completely freely. On the one hand, the angles must be steep enough to allow acceleration of the material pieces, particularly in the longitudinal direction, due to the force of gravity, to occur for their separation. On the other hand, the angles must not be chosen too steeply, as otherwise, material overshoot and / or overtaking effects will occur, which contradicts the desired separation. According to the applicant's studies, the angle ranges specified above are optimal, with a difference of 5° between the angles of inclination being chosen in particular.

[0030] According to a further feature of the invention, the angle of inclination of the feed surface of the first feed unit in the transport direction of the material part is 7° to 13°, preferably 8° to 12°, most preferably 10°. This angle selection ensures that the material parts fed to the feed unit are sufficiently accelerated in the transport direction, while simultaneously achieving the desired distribution of the material parts in the width direction. An excessively steep angle of inclination would disadvantageously result in the desired distribution of the material parts in the width direction not being achieved.

[0031] According to a further feature of the invention, it is provided that the angle of inclination of the feed surface of the second feed unit in the transport direction of the material part is 12° to 18°, preferably 13° to 17°, most preferably 15°.

[0032] After the material parts have been transferred from the first feed unit to the second feed unit, the material parts are accelerated in the transport direction for the purpose of singulating the material parts longitudinally of the feed unit, i.e., in the transport direction. The first step involves pre-separating the material parts, particularly while avoiding overrunning effects. An inclination angle of 10° has proven particularly suitable for achieving this desirable singulation. An even steeper angle design, in particular, would not lead to even greater singulation, but quite the opposite, would lead to partial undesired accumulations of material parts, particularly as a result of overhanging material parts and / or overrunning effects.

[0033] According to a further feature of the invention, it is provided that the angle of inclination of the feed surface of the third feed unit in the transport direction of the material part is 17° to 23°, preferably 18° to 22°, most preferably 20°.

[0034] The material pieces pre-separated by the second feed unit can now be further separated by the third feed unit. The further inclination with respect to the third feed unit is possible while avoiding overshooting material and / or overrunning effects because the material pieces are already pre-accelerated by the second feed unit. The third feed unit thus further separates the material pieces, so that ultimately, material pieces at a defined distance from one another leave the feed device in the direction of the laser device and / or the spectrometer system.

[0035] The three-stage design of the feeder according to the invention, in contrast to the prior art, allows for the processing of a larger quantity of material pieces, while also reliably ensuring uniform distribution in the width direction and separation in the transport direction. The individual stages are coordinated with each other in terms of their respective angle of inclination in such a way that the material pieces to be separated are further accelerated from stage to stage, i.e., from feed unit to feed unit, reliably avoiding undesirable overrunning effects and / or overflowing material pieces.

[0036] According to a further feature of the invention, the inclination angles are adjustable. The adjustability of the inclination angles is particularly advantageous when different material pieces are to be sorted according to size and weight. This allows the respective inclination angles to be optimized for the sorting task. Thus, depending on the size of the material pieces to be sorted and / or their specific weight, the inclination angles of all or even just individual feed units can be adjusted accordingly.

[0037] According to a further feature of the invention, it is provided that the first feed unit in the transport direction of the material part is a vibratory conveyor with an unbalanced drive.

[0038] The first feed unit in the transport direction is used to separate the material pieces or distribute them widthwise. A vibratory conveyor with an unbalanced drive is sufficient for this purpose, making it the preferred choice due to its comparatively low acquisition and maintenance costs.

[0039] According to a further feature of the invention, the second and third feed units are preferably designed as vibratory conveyors with a magnetic drive. In contrast to a vibratory conveyor with an unbalanced drive, a vibratory conveyor with a magnetic drive offers the advantage of continuously variable dosing, allowing more precise control of the conveying speed in the transport direction. The magnetic drive also ensures that any overrun of material parts is essentially eliminated. This ultimately allows for very precise control of the material transport, allowing for targeted influence on the desired separation of the material parts.

[0040] According to a further feature of the invention, it is provided that the detection unit has a further objective, to which a further detection cone is assigned, which forms a further plasma detection area in a further overlap area with the laser beam, wherein the objectives are arranged and / or aligned in relation to one another such that the plasma detection area and the further plasma detection area are arranged offset along the beam axis and together form a field of view of the detection unit.

[0041] This design advantageously provides an enlarged detection area, allowing more material parts to be reliably identified with regard to their composition. Consequently, the sorting result is improved because incorrect sorting is minimized. The result is increased sorting effectiveness.

[0042] The enlarged detection range results from the fact that, unlike the prior art, not just one lens is provided, but several lenses, at least two. However, more than two lenses are preferred, for example, three, four, or even more.

[0043] Each lens creates one plasma detection area. With four lenses, four plasma detection areas are created. According to the invention, the lenses are further arranged and / or aligned relative to one another such that the plasma detection areas are offset along the beam axis of the laser beam and together form the field of view of the detection unit. The field of view represents the overall resulting detection area, which is composed of the individual plasma detection areas and is therefore significantly larger than the prior art.

[0044] According to the prior art, the detection area is formed by only one plasma detection area of ​​a lens. Along the beam axis of the laser beam, such a plasma detection area can typically extend over a distance of 8 to 10 mm. The inventive composition of the detection unit's field of view from individual plasma detection areas arranged offset along the beam axis results in an overall detection area that has an extension of 20 mm, 30 mm, 40 mm, or more in the direction of the beam axis. This advantageously ensures that otherwise undetectable material parts can be reliably detected due to their geometric design, including, in particular, spherical or partially spherical material parts.

[0045] As a result, the system according to the invention allows for improved sorting, since the proportion of rejected material parts that are rejected because their composition cannot be reliably identified is minimized.

[0046] The inventive design of the feed means, on the one hand, and the equipping of the detection unit with an additional lens, on the other hand, result in the synergistic effect of an overall increased throughput. While the inventive feed means may process a greater number of material parts than the prior art, it also requires a detection unit tailored to this. On the other hand, a detection unit equipped with an additional lens will not be fully utilized if the feed means is not capable of individually providing a corresponding quantity of material parts. The inventive feed means, on the one hand, and the further developed detection unit, on the other hand, thus combine to further increase the overall throughput.

[0047] According to a further feature of the invention, a plasma detection region is configured such that, in the event of a plasma being present in the plasma detection region, a measurement portion of the plasma light is detected by the associated lens. Thus, if a laser-induced plasma is present, at least partially, in a plasma region, a measurement portion of the emitted plasma light is detected by the associated lens. With multiple lenses according to the invention, this results in the detection unit being able to detect plasma light in the form of measurement portions from individual lenses.

[0048] According to a further feature of the invention, the plasma detection regions are arranged along the beam axis either merging into one another or spaced apart from one another. Alternatively or additionally, the plasma detection regions can each extend along the beam axis over 1 / 10 to 1 / 4 of the field of view. It is thus possible, particularly after the sorting task, to form an overall resulting detection region by appropriately arranging the plasma detection regions.

[0049] According to a further feature of the invention, the feed means according to the invention for transporting the material part is configured to transport the material part along a feed surface up to an upper section of a chute. According to this preferred embodiment, the material part is fed to the feed means. From there, it reaches a chute, where it is transported along a feed surface of the feed means up to an upper section of the chute. Once the material part has reached the chute, it moves down the chute following gravity. The purpose of the chute is, in particular, to align the material part and transfer it into a defined drop corridor.

[0050] According to a further feature of the invention, it is provided that the sorting unit is assigned to a lower edge of the chute opposite the upper section of the chute, wherein the sorting unit is designed to feed the material part leaving the chute via the lower edge of the chute to one of two fractions.

[0051] According to this preferred embodiment, a piece of material leaves the chute in free fall and is subjected to analysis and sorting in free fall. For this purpose, the laser device and the spectrometer system, in particular, are arranged vertically below the lower edge of the chute.

[0052] Further features and advantages of the invention will become apparent from the following description with reference to the figures. Fig. 1 shows a schematic representation of the system according to the invention; Fig. 2 shows a schematic representation of a supply means according to the invention; Fig. 3 shows a further schematic representation of the functioning of the system according to the invention and Fig. 4 shows an enlarged schematic representation of the spectrometer system according to the system according to the invention according to Fig. 1 .

[0053] Fig. 1 shows a schematic representation of the system 100 according to the invention.

[0054] The system 100 is configured to subject a material part 120 to laser-induced plasma spectroscopy and to sort it depending on the result of the spectral analysis. In the illustrated embodiment, two fractions F1 and F2 are provided, to which the material part 120 can be assigned. Collection points 170, for example in the form of containers, serve to receive the respective fractions F1 and F2.

[0055] As the schematic representation according to Figure 1 As can also be seen, the system 100 has a feeding means 110 followed by a chute 130. In the intended use, a material part 120 is fed to the feeding means 110. The feeding means 110 serves to transport the material part 120 along a feed surface 111 provided by the feeding means, specifically up to an upper section 131 of the chute 130. Here, the material part 120 is transferred from the feeding means 110 to the chute 130.

[0056] The feeding means 110 serves in particular to separate a plurality of material parts 120 fed onto the feeding means 110 so that they can then be fed to the chute 130 at a distance from one another.

[0057] A material part 120 transferred to the chute 130 slides down the chute 130 following gravity until it reaches the lower edge 132 of the chute, which is positioned opposite the upper section 131 of the chute 130. The particular function of the chute 130 is to align the material part 120 and transfer it into a defined drop corridor.

[0058] Upon leaving the chute 130, the material part 120 continues to fall freely through the bypass atmosphere under the influence of gravity. In doing so, it passes through the spectrometer system 1. This ensures an analysis of the material part 120, as will be described in more detail below. In accordance with the result of a performed spectral analysis, the spectrometer system 1 generates an output signal. This signal is fed to a control device 150, which operates, i.e., controls, a sorting unit 160 depending on this output signal on the one hand and a sorting criterion on the other. By means of this sorting unit 160, the material part 120 is either deflected in its free fall or no deflection occurs. If no deflection occurs, the material part 120 reaches the collection point 170 for fraction F2.Otherwise, if sorting takes place by means of the sorting unit 160, the material part 120 reaches the collection point 170 for the fraction F1.

[0059] The spectrometer system 1, which is part of a LIBS module 180, is used to analyze the composition of the material part 120. The LIBS module 180 also includes a laser device 140 and the control device 150. Preferably, the laser device 140, the spectrometer system 1 and the control device 150 are housed in a common housing, which in Figure 1 is not shown in detail.

[0060] The laser device 140 in turn consists of further individual components, for example a laser beam source 9, an optical fiber 9A and a focusing optics 11, as is particularly evident from the embodiment according to Figure 2 can be seen.

[0061] According to the invention, the feed means 110 is designed in three stages, as shown in Fig. 2 can be recognized.

[0062] In the illustrated embodiment, the feed means 110 has three separate feed units 201, 202, and 203. These feed units are arranged in series one behind the other in the transport direction 207 of the material part 120. Each feed unit 201, 202, and 203 provides a feed surface 204, 205, and 206, respectively, along which a material part 120 is moved during its intended use.

[0063] The feed surfaces 204, 205, and 206 are each inclined to the horizontal, forming a respective angle of inclination α 1 , α 2 , and α 3 . According to the invention, the angles of inclination α 1 , α 2 , and α 3 are configured to be of different sizes.

[0064] In their entirety, the feed units 201, 202 and 203 form the feed means 110. The feed area 111 provided by the feed means 110 is divided into the feed areas 204, 205 and 206 of the feed units 201, 202 and 203.

[0065] In the intended use, material parts 120 are fed to the feeding means 110, for example by means of a conveyor 200, which can be designed as a belt conveyor.

[0066] From the conveyor 200, the material parts 120 first reach the first feed unit 201 in the transport direction 207. This feed unit 201 is designed, for example, as a vibratory conveyor with an unbalanced drive and serves primarily to distribute the fed material parts 120 in the width direction, i.e. transversely to the transport direction 207.

[0067] The feed surface 204 of the first feed unit 201 is at an inclination angle α 1 of, for example, 10°. Due to gravity, this assists the transport of the material parts in the transport direction 207.

[0068] From the first feed unit 201, the material parts 120 then reach the second feed unit 202, which is located downstream of the first feed unit 201 in the transport direction 207. The feed surface 205 provided by the second feed unit 202 is at an inclination angle α 2 that is greater than the inclination angle α 1 and is, for example, 15°. This steeper inclination angle α 2 ensures that, due to gravity, a higher transport speed of the material parts 120 is achieved in the transport direction 207. As a result, the material parts 120 are separated in the transport direction 207.

[0069] From the second feed unit 202, the material parts 120 finally reach the third feed unit 203, whose feed surface 206 is inclined at an angle of inclination α 3 to the horizontal. The angle of inclination α 3 is greater than the angle of inclination α 2 of the second feed surface 205 and is, for example, 20°. This even steeper angle of inclination α 3 results in further acceleration of the material parts 120, which leads to an even higher speed of the material parts 120, resulting in even more extensive separation in the transport direction 207.

[0070] Finally, the material parts 120 achieve such a separation in the transport direction 207 that they reach the chute 130 after passing the feed unit 203, so that sorting can then take place as intended in the manner already described above.

[0071] As can be seen in particular from Figure 3The spectrometer system 1 has a detection unit 21, which in turn provides several lenses. Each of these lenses is assigned a detection cone 35, which each form a plasma detection region 39 in an overlap region with the laser beam 5. These plasma detection regions 39 are arranged offset from one another along the beam axis of the laser beam 5 and together form a viewing region 41 of the detection unit 21. The viewing region 41 is thus composed of the individual plasma detection regions 39, thereby defining the detection region covered by the detection unit as a whole.

[0072] Fig. 3shows a schematic overview of a spectrometer system 1 for spectral analysis of a plasma light 3A emitted by a laser-induced plasma 3 (schematically indicated as a filled circle). Detectable plasma light 3A lies, for example, in the wavelength range of UV light, visible light, near-infrared light, and / or infrared light; in particular, the plasma light to be detected can be in the spectral range from approximately 190 nm to approximately 920 nm. In LIBS, the plasma 3 is generated with a laser beam 5 on a surface 7A of a sample 7.

[0073] To generate the, e.g., pulsed, laser beam 5, the spectrometer system 1 comprises a laser beam source 9. The laser beam source 9 is designed to provide the laser beam parameters required for plasma generation. The laser beam 5 is fed, e.g., via an optical fiber 9A, to a focusing optics 11 and from there onto the surface 7A of the sample 7 (material part 120 according to Figure 1). The focusing optics 11 can be designed, in particular, as a laser head component with a focusing function, such as an active laser component with a focusing function that acts, in particular, on the spectrum or the pulse duration or the pulse energy. The propagation of the laser beam 5 between the focusing optics 11 and the sample 7 occurs along a beam axis 5A. Example focus diameters (1 / e 2< beam diameter in the beam waist) and focus lengths (double Rayleigh lengths) are in the range from <50 µm to >250 µm and in the range from <5 mm to >1,000 mm, respectively.

[0074] Laser parameters can in particular be set / selected such that a region in which plasma generation can take place (also referred to as ignition region) extends, for example, over a length in the range of approximately 5 mm to approximately 50 mm, for example over a length of 10 mm, 20 mm or 30 mm, along the beam axis 5A.

[0075] Fig. 3schematically shows a focal zone 11A elongated along the beam axis 5A, as it is formed in the area of ​​the surface 7A of the sample 7. The plasma 3 forms due to the interaction of the laser radiation with the material on the surface of the sample 7A. In LIBS, typical dimensions (average diameter) of a plasma 3 are in the range of, for example, 0.1 mm to 5 mm (depending on the sample material and laser parameters).

[0076] The spectrometer system 1 further comprises an optical spectrometer 13 for spectral analysis of the plasma light 3A. The optical spectrometer 13 is in Fig. 2Illustrated by way of example as a grating spectrometer. In general, the spectrometer 13 comprises at least one dispersive element 13A, e.g., a grating, a prism, or a grating prism, and a pixel-based detector 13B, onto which the plasma light impinges in a spectrally expanded manner. Spectral components of the plasma light 3A to be analyzed are assigned to the pixels of the detector 13B. The detector 13B outputs intensity values ​​of the irradiated pixels to an evaluation unit 15, typically a computer with a processor and a memory. The evaluation unit 15 outputs a measured spectral distribution 17 and compares it, for example, with stored comparison spectra in order to assign the elements contributing to the plasma light 3A to the plasma light 3A and thus to the sample 3 under investigation and to output them as the result of the spectral analysis.

[0077] In the spectrometer 13, a (spectral-dependent) beam entrance for the plasma light to be analyzed is defined by an entrance aperture 19, usually an entrance slit 19A.

[0078] The spectrometer system 1 further comprises a detection unit 21 with an objective mount 23 and a plurality of objectives 25A, 25B, 25C held by the objective mount 23. Three objectives are shown in the figures as an example: two in the image plane and one behind it. The number of objectives used can be selected depending on spatial and optical parameters as well as parameters of the material of the sample to be examined; it is, for example, in the range from 2 to 20, for example, 4, 5, 8, 9, or 15 objectives.

[0079] The spectrometer system 1, in particular the detection unit 21, further comprises an optical light guide system 27 that optically connects the objectives 25A, 25B, 25C to the spectrometer 13. The light guide system 27 provides a plurality of optical inputs 29, each optically associated with one of the objectives 25A, 25B, 25C, and an optical output 31 (functionally common to the objectives) that is optically associated with the entrance aperture 19.

[0080] Each of the lenses 25A, 25B, 25C is configured to capture a measurement portion 33 of the plasma light 3A and includes at least one focusing optical element, such as a converging lens or a concave mirror. A detection cone 35 is assigned to each of the lenses 25A, 25B, 25C. The beam axis 5A extends through the detection cones 35, with the detection cones 35 having a set minimum size in the region of the laser beam 5. Each of the detection cones 35 includes, in an overlap region with the laser beam 5, a plasma detection region 39 that is assigned to the corresponding lens 25A, 25B, 25C. For example, the detection cones 35 have a length from an entrance aperture of a lens to the laser beam in the range of 200 mm to 400 mm. For example, Fig. 2The plasma 3 is generated in the plasma detection area 39 of the lens 25B, so that the corresponding measurement portion 33 of the plasma light 3A is captured by the lens 25B and imaged onto the associated optical input 29 of the light guide system 27. Measurement portions 33 captured by one or more lenses are guided by the optical light guide system 27 to the common optical output 31 and coupled through the entrance aperture 19 into the optical spectrometer 13 for spectral analysis.

[0081] Fig. 3 shows, as an example, three lenses 25A, 25B, 25C, which are arranged azimuthally distributed around the beam axis 5A. The lenses 25A and 25B are located on opposite sides of the beam axis 5A and are thus directed onto the beam axis 5A from opposite sides. The lens 25C is directed onto the beam axis 5A from behind. Another lens (in Fig. 2not shown) can, for example, be directed from the front onto the beam axis 5A or, using a beam splitter, along the beam axis 5A onto the focus zone 11A. For clarification, Fig. 2 the detection cones 35 are indicated by dashed lines as tapering conically towards the beam axis 5A, whereby the focus zone 11A, the plasma 3 and the plasma detection areas 39 are shown oversized compared to the detection cones 35 for clarity.

[0082] Fig. 4 shows once again a detailed view of the inventive system 100 according to Fig. 1It can be seen here that different material parts are provided in their composition, namely material parts 120B made of plastic and material parts 120A made of aluminum. In the manner already described, sorting can take place by means of the spectrometer system 1 according to the invention such that the material parts 120A are separated from the material parts 120B. For this purpose, if a material part 120B made of plastic is detected, this is ejected by means of the sorting unit 160. For this purpose, the sorting unit 160 has an air pressure nozzle by means of which a plastic part 120B can be ejected from the stream of material parts. As a result of such sorting, material parts 120B made of plastic on the one hand and material parts 120A made of aluminum on the other hand collect separately at the collection points 170. Reference symbol

[0083] 1Spectrometer system 3Plasma 3APlasma light 5Laser beam 5ABeam axis 7Sample 7ASurface 9Laser beam source 9AOptical fiber 11Focusing optics 11AFocal zone 13Optical spectrometer 13ADispersive element 13BDetector 15Evaluation unit 17Spectral distribution 19Entrance aperture 19AEntrance slit 21Detection unit 23Lens holder 25ALens 25BOlens 25COlens 25DOlens 27Light guide system 29Optical input 31Optical output 33Measurement portion 35Detection cone 39Plasma detection area 41Viewing area 100System 110Feeding means 111Feeding means 120Material part 120AAluminum part 120BPlastic part 130 Chute 131 Upper section 132 Lower edge 140 Laser device 150 Control device 160 Sorting unit 170 Collection point 180 LIBS module 200 Conveyor 201 Feed unit 202 Feed unit 203 Feed unit 204 Feed surface 205 Feed surface 206 Feed surface 207 Transport direction α 1 Inclination angle α 2 Inclination angle α 3 Inclination angle

Claims

1. System for analyzing and sorting a piece of material, in particular an aluminum scrap part, the system comprising: - a feeder (110) for transporting the piece of material (120); - a sorting unit (160) configured to feed the piece of material (120) to one of two fractions (F1, F2), - a laser device (140) configured to generate a plasma (3) on a surface 7A of the piece of material (120) by means of a laser beam (5A) propagating along a beam axis (5A), - a spectrometer system (1) configured to carry out a spectral analysis of the plasma light (3A) emitted from the laser-induced plasma (3) and to generate an output signal corresponding to the result of the spectral analysis that has been carried out, and - a control device (150) configured to receive the output signal and to operate the sorting unit (160) based on the output signal and on a sorting criterion, - wherein the spectrometer system (1) comprises a spectrometer and a detecting unit (21) optically coupled with the spectrometer (13), - wherein the detection unit (21) has an objective (25A, 25B, 25C, 25D) to which a detection cone (35) is assigned, which detection cone creates a plasma detection region in an overlapping region (37) with the laser beam (5), characterized in that the feeder (110) comprises three single feeding units (201, 202, 203) arranged one behind the other in the transport direction (207) of the piece of material (120), wherein each feeding unit (201, 202, 203) is respectively configured to transport the piece of material (120) along a feeding surface (204, 205, 206) provided by the respective feeding unit (201, 202, 203), wherein the feeding surfaces (204, 205, 206) are aligned inclined to the horizontal while forming a respective inclination angle (α1, α2, α3), wherein the inclination angles (α1, α2, α3) are different, wherein the inclination angle (α1) of the feeding surface (204) of the first feeding unit (201) in the transport direction (207) is smaller than the inclination angle (α2) of the feeding surface (205) of the second feeding unit (202) in the transport direction (207) and the inclination angle (α2) of the feeding surface (206) of the second feeding unit (202) in the transport direction (207) is smaller than the inclination angle (α3) of the third feeding unit (203) in the transport direction (207).

2. System according to claim 1, characterized in that the difference between the inclination angles (α1, α2, α3) is 2° to 8°, preferably 3° to 7°, most preferably 5°.

3. System according to any one of the preceding claims, characterized in that the inclination angle (α1) of the feeding surface (204) of the first feeding unit (201) in the transport direction (207) is 7° to 13°, preferably 8° to 12°, most preferably 10°.

4. System according to any one of the preceding claims, characterized in that the inclination angle (α2) of the feeding surface (205) of the second feeding unit (202) in the transport direction (207) is 12° to 18°, preferably 13° to 17°, most preferably 15°.

5. System according to any one of the preceding claims, characterized in that the inclination angle (α3) of the feeding surface (206) of the third feeding unit (203) in the transport direction (207) is 17° to 23°, preferably 18° to 22°, most preferably 20°.

6. System according to any one of the preceding claims, characterized in that the inclination angles (α1, α2, α3) are adjustable.

7. System according to any one of the preceding claims, characterized in that the first feeding unit (201) in the transport direction (207) is a vibratory conveyer with unbalance drive.

8. System according to any one of the preceding claims, characterized in that the second and the third feeding aggregates (202, 203) in the transport direction are in each case a vibratory conveyor with magnetic drive.

9. System according to any one of the preceding claims, characterized in that the detection unit (21) comprises a further objective (25A, 25B, 25C, 25D) to which a further detection cone (35) is assigned, which detection cone forms a further plasma detection region (39) in a further overlapping region (37) with the laser beam (5), wherein the objectives (25A, 25B, 25C, 25D) are arranged in relation to one another and / or aligned in such a way that the plasma detection region (39) and the further plasma detection region (39) are offset from each other along the beam axis (5A) and together form a field of vision of the detection unit (21).

10. System according to claim 1, characterized in that a plasma detection region (39) is configured in such a way that in the case of a plasma (3) present in the plasma detection region (39) a measuring share (33) of the plasma light (3A) is detected by the associated objective (25A, 25B, 25C, 25D).

11. System according to any one of the preceding claims, characterized in that the plasma detection regions (39) are arranged in such a way that they pass into one another or are spaced from one another along the beam axis (5A).

12. System according to claim 1 or 2, characterized in that that the objective mount (23) provides an optical passage opening (43) through which the beam axis (5A) extends.

13. System according to claim 1, characterized in that the sorting unit (160) is assigned to a lower edge (132) of a chute (130) opposite an upper section (131) of the chute, wherein the sorting unit (160) is configured to feed the piece of material (120) leaving the chute (130) via the lower edge (132) of the chute (1340) to one of two fractions (F1, F2).

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