System for analysing and sorting a material part
Patent Information
- Application Number
- EP2023745484
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2022-08-19
- Filing Date
- 2023-07-21
- Publication Date
- 2025-06-25
- Estimated Expiration
- Not applicable · inactive patent
AI Technical Summary
Existing systems for sorting scrap aluminum parts using laser-induced plasma spectroscopy face inefficiencies due to limited throughput and separation capabilities, leading to suboptimal sorting results, especially when dealing with large numbers of parts that are not clearly identified in their composition.
A three-stage feed system with inclined feed surfaces of varying angles is introduced, allowing for increased acceleration and separation of material parts, combined with an enhanced detection unit featuring multiple lenses and a protective housing to improve detection range and reduce dust interference, along with a compressed air nozzle optimized for closer proximity to the laser beam.
This configuration significantly increases sorting efficiency and throughput by ensuring proper separation and identification of material parts, reducing incorrect sorting and maintaining consistent sorting quality over time.
Smart Images
Figure 1.1
Abstract
Description
[0001] System for analyzing and sorting a piece of material
[0002] The invention relates to a system for analyzing and sorting a material part, in particular a scrap part made of aluminum, comprising: a feed means for transporting the material part, a sorting unit configured to feed the material part to one of two fractions, a laser device configured to generate a plasma on a surface of the material part using a laser beam propagating along a beam axis, a spectrometer system configured to perform a spectral analysis of a plasma light emitted by the laser-induced plasma and to generate an output signal in accordance with a result of the performed spectral analysis, and a control device configured to receive the output signal and operate the sorting unit based on the output signal and a sorting criterion.wherein the spectrometer system comprises a spectrometer and a detection unit optically connected to the spectrometer,
[0003] - wherein the detection unit has an objective lens to which a detection cone is assigned, which forms a plasma detection area in an overlap area with the laser beam, wherein the feed means has three individual feed units arranged one behind the other in the transport direction of the material part, wherein each feed unit is designed to transport the material part along a feed surface provided by the respective feed unit, wherein the feed surfaces are each aligned inclined to the horizontal to form a respective angle of inclination, wherein the angles of inclination are designed differently.
[0004] A system for analyzing and sorting a material part is known from EP 3352 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.
[0005] In addition, DE 91 06292 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.
[0006] 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.
[0007] 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 device and a feed device that feeds bulk material to the vibratory conveyor device, 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 device, onto which roller the bulk material conveyed via the end of the vibratory conveyor device reaches 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 device 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.
[0008] 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.
[0009] According to EP 3 352 919 B1, the material pieces to be analyzed and sorted are fed into a chute using 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.
[0010] During the 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.
[0011] 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.
[0012] 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.
[0013] 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.
[0014] Therefore, based on the above-described prior art, the object of 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.
[0015] To achieve this object, a system of the type mentioned at the outset is proposed, which is characterized in that the angle of inclination of the feed surface of the first feed unit in the transport direction is smaller than the angle of inclination of the feed surface of the second feed unit in the transport direction and in that the angle of inclination of the feed surface of the second feed unit in the transport direction is smaller than the angle of inclination of the feed surface of the third feed unit in the transport direction.
[0016] According to EP 3 352 919 B1, a feed means is used to transport the material part, which feed surface provides a feed surface along which the material part is moved during its intended use. The feed means can be designed, for example, as an oscillating plate. It serves, in particular, to separate a plurality of material parts placed on the feed means so that they can subsequently be fed to the laser device and / or the spectrometer system at a distance from one another. However, the separation achieved with the feed means previously known from EP 3 352 919 B1 is limited, thus allowing only a comparatively low throughput.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 device has at least three feeding units. These are each designed as an independent assembly. Therefore, at least three separate, i.e. individual, feeding units are provided. These are arranged in the transport direction of the material part.
[0018] arranged in a row, whereby 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
[0019] These feed units together form the feeding means according to the invention
[0020] 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.
[0021] 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.
[0022] The feed units each provide, for example, an oscillating plate which provides the respective feed surface. As a result of the oscillating movement of such a plate, a material part located thereon is transported in the transport direction. The inclined alignment of the respective feed surfaces provided according to the invention supports this transport, since the oscillating movement is supplemented by the force of gravity acting on the material part. In this context, it is further provided that the angles of inclination of the feed surfaces are designed to be different. As a result, the different angles of inclination lead to 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 influence is greater the greater the angle of inclination.
[0023] 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.
[0024] 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.
[0025] 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.
[0026] 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.
[0027] 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.
[0028] Due to the even steeper incline of the third feed unit compared to the second feed unit, a further acceleration of the material pieces in the transport direction is achieved. 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 material pieces in the width direction and the two further feed units each separate the material pieces in the length direction, whereby as a result, separated material pieces are fed to the laser device or the 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.
[0029] 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°.
[0030] 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 in order to separate them. On the other hand, the angles must not be chosen too steeply, as otherwise, material overshoot and / or over-pulling 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.
[0031] 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.
[0032] 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°
[0033] 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.
[0034] 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°.
[0035] 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.
[0036] The three-stage design of the feeding device 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 one another with regard to 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.
[0037] According to a further feature of the invention, the angles of inclination are adjustable. The adjustability of the angles of inclination is particularly advantageous when different material parts are to be sorted according to size and weight. This is because it is particularly possible to set the respective angles of inclination in an optimized manner with regard to the sorting task. In particular, depending on the size of the material parts to be sorted and / or their specific weight, the angles of inclination of all or just individual feed units can be adjusted accordingly. According to a further feature of the invention, 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 lagging 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 field of view of the detection unit 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 larger 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 providing a corresponding quantity of material parts individually. The inventive feed means on the one hand and the further developed detection unit on the other hand thus combine to ensure an overall even further increased 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] According to a further feature of the invention, it is provided that the detection unit carries a protective housing that surrounds the laser beam and the detection cone.
[0053] A protective housing is provided to protect both the laser beam and the lens' detection cone from unwanted dust or particles from the outside. Dust-related fluctuations in sorting efficiency are thus effectively minimized, ensuring at least consistently good sorting efficiency over time.
[0054] The protective housing surrounds the laser beam and the detection cone. The laser beam and the detection cone are thus guided through a volumetric interior provided by the protective housing. Thanks to the encapsulation provided by the protective housing, this volumetric interior is largely free of foreign particles, particularly dust particles and / or similar contaminants, so that neither the laser beam nor the detection cone are impaired in their functionality. Furthermore, the protective housing advantageously ensures that dust or other foreign particles cannot accumulate unintentionally, particularly on the optics, thus minimizing the risk of lens defects caused by such particles burning in.
[0055] The protective housing thus ensures, on the one hand, that the volume provided by the protective housing and traversed by both the laser beam and the detection cone is kept largely free of dust or similar foreign particles, and, on the other hand, that dust or other foreign particles do not accumulate on the optics or clog the through-hole. As a result, sorting efficiency is ensured that remains at least consistent, if not even increased, over time, and this is achieved in a structurally simple and therefore cost-effective manner.
[0056] According to a further feature of the invention, the protective housing extends along the beam axis of the laser beam. The protective housing is arranged on the detection unit, is thus supported by it, and extends from the detection unit in the direction of the longitudinal axis of the laser beam, thus along the beam axis. The laser beam and thus also the detection area of the lens are thus enclosed by the protective housing, thus providing reliable shielding of both the lens and the laser beam aperture from dust or other foreign particles.
[0057] According to a further feature of the invention, it is provided that the protective housing extends over part of the distance between the detection unit and the plasma detection area.
[0058] The plasma detection area is located outside the protective housing. Otherwise, proper material detection would not be possible. To ensure that both the laser beam and the detection cone are directed to the plasma detection area with as little dust or foreign particles as possible, the protective housing extends over at least part of the distance between the detection unit and the plasma detection area. Preferably, the protective housing extends all the way to the plasma detection area, so that the entire section between the detection unit and the plasma detection area is covered by the protective housing as far as possible.
[0059] According to a further feature of the invention, the protective housing is a truncated cone-shaped tube section. The protective housing is thus designed as a tube that tapers toward the plasma detection area. This taper advantageously achieves two things. First, the protective housing is large enough toward the detection unit to fully accommodate the optics provided by the detection unit, on the one hand, and the through-opening for the laser provided by the detection unit, on the other. The entire optics and the through-opening are thus covered by the protective housing and thus protected from unwanted external influences.As a result of the tapering of the protective housing toward the plasma detection area, an exit opening is provided that is as small as possible, but still sufficiently large enough for the laser beam and the detection cone to form as desired in the plasma detection area, i.e., their formation is not impaired by the protective housing. The exit cross-section of the protective housing should therefore be as small as possible to minimize unwanted dust or foreign particles from entering the protective housing through the exit opening. In this context, it is preferred that the exit opening has a diameter of 9 mm to 13 mm, preferably 10 mm to 12 mm, and even more preferably 11 mm.
[0060] According to a further feature of the invention, it is provided that the protective housing is connected to a compressed air supply on the laser beam inlet side.
[0061] The compressed air supply makes it possible to flood and flow air through the protective housing. The air is fed into the protective housing on the laser beam side, so that the air flows through the protective housing in the direction of laser beam propagation and exits through the outlet opening.
[0062] Air purging the protective housing provides two main advantages. Firstly, the protective housing is kept completely free of unwanted dust or foreign particles, as any dust or other foreign particles that might enter the protective housing through the outlet opening are blown out by compressed air. Secondly, an air column forms around the laser beam on the outlet side. This also keeps the plasma detection area free of dust or other foreign particles, allowing dust-free access to the material to be sorted using the laser beam. This optimizes laser detection, further increasing the sorting efficiency of the system according to the invention.
[0063] According to a further feature of the invention, the protective housing is made of a material that provides an inner surface that minimizes reflection. Plastic, in particular, is suitable as a material, as unlike metal, it does not provide a shiny surface. Any stray light penetrating the protective housing from the outside is thus largely absorbed, enabling optimized lens utilization, as no stray light effects impair lens operation.
[0064] In this context, according to a further feature of the invention, it is proposed that the inner surface of the protective housing be roughened. The roughening ensures that any stray light effects that may occur lead to diffuse reflection, which contributes to maximizing the light absorption rate. Both the choice of material and the design of the inner surface can therefore advantageously ensure that an additional increase in efficiency is achieved by avoiding impairment of the optics by stray light. The protective housing according to the invention thus achieves two effects in a synergistic manner. Firstly, influences by dust or other foreign particles are minimized, and secondly, the optics are shielded against stray light.As a result of the design according to the invention, not only can a sorting efficiency and quality that remains constant over time be ensured, but in contrast to the prior art, there is also an increase in sorting efficiency and quality. The system according to the invention therefore allows for an increased throughput, in contrast to the prior art. According to a further feature of the invention, it is provided that the sorting unit has a compressed air nozzle with an outlet opening of greater than 3 mm, wherein the compressed air nozzle is arranged at a distance from a laser beam generated by the laser device in the direction of movement of a piece of material passing through the laser beam, wherein the distance between the laser beam and the center of the outlet opening of the compressed air nozzle is less than 10 mm.
[0065] The compressed air nozzle of the sorting device is used to implement the material part detection performed by the detection unit by applying pressure to identified material parts using the dosing unit and then ejecting them as a result of the pressure. A state-of-the-art
[0066] A compressed air nozzle typically has an outlet diameter of 3 mm. The invention proposes selecting a significantly larger outlet diameter, in any case greater than 3 mm. Furthermore, the invention provides that the distance between the compressed air nozzle and the laser beam is reduced, in contrast to the prior art, to less than 10 cm. According to the prior art, the distance between the laser beam and the compressed air nozzle is typically 10 cm or more.
[0067] The combination of the larger outlet opening diameter compared to the prior art on the one hand and the larger distance between the laser beam and the compressed air nozzle on the other hand, in contrast to the prior art, advantageously achieves an increased throughput of material parts to be sorted.
[0068] With a typical falling speed of the material pieces to be sorted and a nozzle opening time of 30 ms, as provided for in the state of the art, the material pieces to be sorted must be fed into the sorting unit at a distance of at least 9 cm to ensure optimal sorting. As the distances between the individual material pieces shorten and fall below 9 cm, individual material pieces can no longer be accurately hit by the compressed air nozzle, resulting in reduced sorting quality.
[0069] The inventive design provides a remedy here. Firstly, the invention provides for the distance between the laser beam on the one hand and the compressed air nozzle on the other hand, i.e. the distance between the laser beam and the center of the outlet opening of the compressed air nozzle, to be shortened, in contrast to the prior art, and to be selected to be less than 10 cm. This shortening of the distance ensures that the material pieces in free fall towards the laser beam can approach each other less closely, which in turn makes it possible to separate the material pieces at a reduced distance. Since the fall distance is minimized due to the shortening of the distance, a shorter fall time also results, so that the distance maintained between the material pieces during a previous separation is not significantly altered even by a free fall towards the laser device.Consequently, the spacing chosen by separating the material parts can be shortened, which allows for a higher throughput.
[0070] Since the distance between individual material pieces caused by separation can be shortened as described above, a shorter switching time for the compressed air nozzle is also possible. This, in turn, allows the outlet opening diameter to be increased compared to the prior art, so that a larger effective area is created by the compressed air nozzle. However, this increased effective area, compared to the prior art, does not lead to neighboring material pieces of the material piece actually being ejected being inadvertently ejected when compressed air is applied, because, unlike the prior art, the switching time of the compressed air nozzle can be reduced due to the reduction in distance.However, increasing the outlet diameter enables more reliable capture and thus discharge of the material to be discharged. The synergistic effect of the two inventive features results in both improved discharge quality and increased throughput. As a result, sorting efficiency can be significantly increased compared to the prior art.
[0071] According to the state of the art, it has been assumed to select the outlet diameter of the compressed air nozzle as small as possible, namely 3 mm and smaller. This is to ensure that only the material parts to be ejected are exposed to compressed air, and not the material parts adjacent to the part being ejected. It has not been recognized that the outlet diameter of the compressed air nozzle and the distance between the compressed air nozzle and the laser beam are related in such a way that shortening the distance between the laser beam and the compressed air nozzle allows the outlet diameter of the compressed air nozzle to be increased.Due to a shortened distance between the compressed air nozzle and the laser beam, catching-up and / or overtaking effects with regard to the material pieces in free fall can be minimized, so that despite the larger outlet opening diameter, there is no risk of capturing material pieces adjacent to a material piece to be ejected. However, the larger outlet opening diameter allows for more reliable capture of material pieces to be ejected, so that, in combination with the shortened distance between the compressed air nozzle and the laser beam, this results in an increased throughput and simultaneously improved sorting quality, unlike the prior art. According to a further feature of the invention, the outlet opening diameter is 5 mm to 8 mm, preferably 6 mm to 7 mm, most preferably 6.5 mm.
[0072] As the applicant's investigations have shown, the outlet opening diameter can be selected significantly larger than 3 mm. The size of the outlet opening diameter must be optimized depending on the distance between the compressed air nozzle and the laser beam, on the one hand, and the material parts to be sorted, on the other. In this context, an outlet opening diameter of 6 mm to 7 mm is particularly preferred.
[0073] According to a further feature of the invention, the distance between the laser beam and the center of the outlet opening of the compressed air nozzle is 8 cm to 3 cm, preferably 6 cm to 3.5 cm, even more preferably 5 cm to 4 cm, most preferably 4.5 cm.
[0074] The shortening of the distance between the laser beam and the center of the outlet opening of the compressed air nozzle, which is provided for in contrast to the prior art, provides the advantages already mentioned. Investigations by the applicant have shown that, with an appropriately selected outlet opening diameter of the compressed air nozzle, a significant shortening of this distance is possible in contrast to the prior art. The shorter the distance between the laser beam and the compressed air nozzle, the less likely it is that the material pieces will catch up and / or overtake the laser beam in free fall. If the material pieces are sufficiently separated, there is a distance between two successive material pieces such that, when compressed air is applied to the compressed air nozzle to eject one material piece, neighboring material pieces of the material piece to be ejected are not also caught.As a result, the quality of sorting increases, as it prevents material parts from being incorrectly rejected despite clear identification.
[0075] According to a further feature of the invention, the sorting unit comprises a solenoid valve which interacts with the compressed air nozzle, the compressed air nozzle and the solenoid valve being structurally separated from one another. The structural separation of the compressed air nozzle and the solenoid valve allows for optimized use of the installation space available in the immediate vicinity of the laser device, ensuring that the distance between the compressed air nozzle and the laser beam generated by the laser device during its intended use is as small as possible. The spatial separation of the compressed air nozzle and the solenoid valve therefore has the advantage that the installation space available in the immediate vicinity of the laser device is not unnecessarily wasted by also accommodating the solenoid valve. Rather, this space remains free so that the compressed air nozzle can be optimally aligned in terms of its distance from the laser device.
[0076] According to a further feature of the invention, the compressed air nozzle is fluidically connected to the solenoid valve via a compressed air line. According to this proposal of the invention, the otherwise conventional direct fluidic connection between the compressed air nozzle and the solenoid valve is replaced by a compressed air line, which can be designed, for example, as a hose. This makes it possible to structurally separate the compressed air nozzle and the solenoid valve from one another, whereby the intended functionality of the compressed air nozzle is not impaired.
[0077] According to a further feature of the invention, it is provided that the switching time of the solenoid valve is less than 30 ms, preferably less than 20 ms, even more preferably less than 10 ms.
[0078] This shortened switching time, compared to the prior art, is made possible by the inventive design and results in a significantly higher throughput. Thus, twice the amount, if necessary even three times the amount, of material parts can be sorted as intended per unit of time.
[0079] Further features and advantages of the invention will become apparent from the following description with reference to the figures.
[0080] Fig. 1 shows a schematic representation of the system according to the invention; Fig. 2 shows a schematic representation of a feed means according to the invention;
[0081] Fig. 3 shows a further schematic representation of the functioning of the system according to the invention;
[0082] Fig. 4 shows an enlarged schematic representation of the spectrometer system according to the system according to the invention shown in Fig. 1;
[0083] Fig. 5 shows a further schematic representation of the functioning of a LIBS module of the system according to the invention;
[0084] Fig. 6 shows a schematic side view of a section of the module according to Fig. 5;
[0085] Fig. 7 shows a partially sectioned side view of a protective housing according to the invention and
[0086] Fig. 8 shows a schematic representation of an embodiment according to the invention and
[0087] Arrangement of a compressed air nozzle,
[0088] Fig. 1 shows a schematic representation of the system 100 according to the invention.
[0089] 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.
[0090] As the schematic representation of Figure 1 further shows, the system 100 has a feed means 110 followed by a chute 130. In the intended use, a material part 120 is fed to the feed means 110. The feed means 110 serves to transport the material part 120 along a feed surface 111 provided by the feed means, specifically up to an upper section 131 of the chute 130. Here, the material part 120 is transferred from the feed means 110 to the chute 130. The feed means 110 serves in particular to separate a plurality of material parts 120 fed onto the feed means 110, so that they can then be fed to the chute 130 at a distance from one another.
[0091] A material part 120 transferred to the chute 130 slides down the chute 130 following the force of gravity until it reaches the lower edge 132 of the chute, which is formed opposite the upper section 131 of the chute 130. In particular, the task of the chute 130 is to align the material part 120 and to transfer it into a defined fall corridor.
[0092] 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 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.
[0093] 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 is not shown in detail in Figure 1.
[0094] 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 can be seen in particular from the embodiment according to Figure 2.
[0095] According to the invention, the feeding means 110 is designed in three stages, as can be seen in the illustration in Fig. 2. In the illustrated embodiment, the feeding means 110 has three separate feeding units 201, 202, and 203. These feeding units are arranged in series one behind the other in the transport direction 207 of the material part 120. Each feeding unit 201, 202, and 203 provides a feeding surface 204, 205, and 206, respectively, along which a material part 120 is moved during its intended use.
[0096] The feed surfaces 204, 205, and 206 are each inclined to the horizontal, forming a respective inclination angle ch, a2, and a3. According to the invention, the inclination angles ch, a2, and a3 are of different sizes.
[0097] In their entirety, the feeding units 201, 202 and 203 form the feeding means 110. The feeding area 111 provided by the feeding means 110 is divided into the feeding areas 204, 205 and 206 of the feeding units 201, 202 and 203.
[0098] 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.
[0099] 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, that is, transversely to the transport direction 207.
[0100] The feed surface 204 of the first feed unit 201 is at an inclination angle eh of, for example, 10°. Due to gravity, this assists the transport of the material parts in the transport direction 207.
[0101] From the first feed unit 201, the material parts 120 then reach the second feed unit 202, which is arranged 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 a2, which is greater than the inclination angle Ch and is, for example, 15°. This steeper inclination angle a2 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
[0102] Material parts 120 in transport direction 207.
[0103] 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 a3 to the horizontal. The angle of inclination a3 is greater than the angle of inclination a2 of the second feed surface 205 and is, for example, 20°. This even steeper angle of inclination a3 causes further acceleration of the material parts 120, which leads to an even higher speed of the material parts 120, resulting in even greater separation in the transport direction 207.
[0104] 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.
[0105] As can be seen in particular from Figure 3, the spectrometer system 1 has a detection unit 21, which in turn provides several lenses. Each of these lenses is assigned a detection cone 35, each of which forms 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 field of view 41 of the detection unit 21. The field of view 41 is thus composed of the individual plasma detection regions 39, thereby defining the detection region covered by the detection unit as a whole.
[0106] Fig. 3 shows 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.
[0107] 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 focused by this 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. Exemplary focus diameters (1 / e 2 -Beam diameter in the beam waist) and focus lengths (double Rayleigh lengths) are in the range of <50 pm to >250 pm and in the range of <5 mm to >1,000 mm, respectively.
[0108] 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.
[0109] Fig. 3 schematically 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).
[0110] The spectrometer system 1 further comprises an optical spectrometer 13 for spectral analysis of the plasma light 3A. The optical spectrometer 13 is shown in Fig. 2 as an example of a grating spectrometer. Generally, 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 it as the result of the spectral investigation.
[0111] 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.
[0112] The spectrometer system 1 further comprises a detection unit 21 with an objective lens holder 23 and a plurality of objectives 25A, 25B, 25C held by the objective lens holder 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.
[0113] 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.
[0114] 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 a plasma detection region 39 in an overlap region with the laser beam 5, which 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. An example is shown in Fig.2, the 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.
[0115] Fig. 3 shows, by way of 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 25B is directed onto the beam axis 5A from behind. Another lens (not shown in Fig. 2) can, for example, be directed onto the beam axis 5A from the front or, using a beam splitter, onto the focus zone 11A along the beam axis 5A. For clarity, the detection cones 35 are indicated in dashed lines in Fig. 2 as tapering conically towards the beam axis 5A, with the focus zone 11A, the plasma 3 and the plasma detection areas 39 being shown oversized compared to the detection cones 35 for clarity.
[0116] Fig. 4 once again shows a detailed view of the system 100 according to the invention shown in Fig. 1. It can be seen here that different material parts are provided in its 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, the same is ejected by means of the sorting unit 160. For this purpose, the sorting unit 160 has an air pressure nozzle 400 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.
[0117] Fig. 4 shows a mounting plate 23A of the detection unit 21 of the LIBS system to illustrate the arrangement and alignment of the lenses 25A, 25B, 25C. For stationary mounting of the lenses, the mounting plate 23A has lens mounting openings for receiving the lenses 25A, 25B, 25C. The lens mounting openings are each arranged at a radial distance from the beam axis 5A and are designed for an oblique alignment of the lenses 25A, 25B, 25C to the beam axis 5A. As indicated in Fig. 4, the plasma detection regions 39 together form a viewing region 41 of the detection unit 21. The viewing region 41 extends along the beam axis 5A in the region of the focus zone 11A.
[0118] Furthermore, Fig. 2 shows an optical through-opening 43 in the holder plate 23A, which serves to direct the laser beam through the holder 23 and past the objectives 25A, 25B, 25C onto the sample 7.
[0119] Fig. 5 shows a perspective view of an exemplary LIBS measuring head connected to a laser beam source via an optical fiber 9A. The holder 23 of the LIBS measuring head comprises a longitudinal support plate 23B, on which a mount for the optical fiber 9A and the focusing optics 11 (laser head with beam shaping) is provided on the input side. The optical spectrometer 13 is also attached to the longitudinal support plate 23B, as well as the mounting plate 23A for four lenses 25A, 25B, 25C, 25D (generally an n>1-fold entrance optics). The lenses 25A, 25B, 25C, 25D are configured to capture measurement components of plasma light from plasma detection areas 39, which are arranged offset from one another along the beam axis 5A, and to feed them to the spectrometer 13 for spectral analysis via the fiber optic system 27 (for example, a fiber bundle with n>1 inputs and one functional output - "n-to-1 fiber bundle"). Examples are shown in Fig.Three optical fibers 45 of the fiber optic system 27 are shown, which optically connect the lenses to the common spectrometer 13. Using the fiber optic system 27, the measurement components can be combined for a single measurement process in the spectrometer 13 (or optionally before coupling into the spectrometer 13).
[0120] Figure 6 shows a schematic side view of a section of the module according to Figure 5, wherein the mounting plate 23A is equipped with a protective housing 300 according to the invention.
[0121] As can be seen from the illustration in Figure 6, the protective housing 300 is a truncated cone-shaped tubular section. This extends along the beam axis 5A of the laser beam 5, starting from the mounting plate 23A, up to the viewing area 41, i.e., up to the first plasma detection area 39 in the propagation direction of the laser beam 5. The protective housing 300 thus essentially bridges the distance between the plasma detection area 39 and the mounting plate 23A in the longitudinal direction of the laser beam 5.
[0122] The protective housing 300 surrounds both the laser beam 5 and the detection cones 35, which are respectively assigned to the lenses 25A to 25D. The laser beam 5 and the detection areas 35 are thus enclosed by the protective housing 300.
[0123] The protective housing 300 essentially achieves two effects. Firstly, the lenses 25A to 25D, as well as the optical through-opening 43 formed in the mounting plate 23A for the laser beam 5, are protected from the unwanted influence of dust and / or other foreign particles originating from the environment. Unwanted impairment of the lenses 25A to 25D and the through-opening 43 by dust and / or other foreign particles is thus largely eliminated.
[0124] On the other hand, the volume space provided by the protective housing 300 and traversed by both the laser beam 5 and the detection cones 35 during intended use is kept free of dust and / or other foreign particles, so that both the laser beam 5 and the detection cones 35 are unimpaired in their intended function.
[0125] The protective housing 300 is connected to a compressed air unit (not specifically shown in the figures). This unit can be used to supply compressed air to the protective housing 900 on the mounting plate side, which flows through the protective housing 300 in the propagation direction of the laser beam 5. As a result of such air flow, any dust and / or other foreign particles are effectively prevented from penetrating the protective housing 300 via the outlet opening 303 of the protective housing 303, which is located on the plasma detection area side.
[0126] The air supply to the protective housing 300 further provides the advantage that an air cone or column 301 is formed on the outlet side of the protective housing 300, which surrounds the laser beam 5. This achieves the positive effect that the viewing area 41, composed of the plasma detection areas 39, is also kept largely free of dust and / or other foreign particles.
[0127] Figure 7 shows a partial, partially sectioned side view of the protective housing 300 according to the invention. As can be seen particularly from this illustration, the protective housing 300 is truncated conically and provides the exit opening 303 on the output side. This opening is preferably circular in cross-section and is traversed centrally by the laser beam 5.
[0128] The protective housing 300 is preferably made of plastic, with minimal or even no reflective properties. Any stray light penetrating the protective housing 200 through the exit opening 303 is thus largely absorbed, preventing any impairment of the optics covered by the protective housing 300 due to reflected stray light. In this context, it is further provided to roughen the inner surface 303 of the protective housing 200. This leads to a diffuse reflection when stray light penetrates the protective housing, which also helps to minimize any unwanted impairment of the lenses 25A to 25D covered by the protective housing 300.
[0129] Fig. 8 shows in a purely schematic representation the design and arrangement of a compressed air nozzle 400 according to the invention.
[0130] As can be seen from Fig. 8, the compressed air nozzle 400 is arranged at a distance from a laser beam 5 generated by the laser device 140 in the direction of movement 401 of a material part 120 passing through the laser beam 5. This distance A between the laser beam 5 and the center of the outlet opening 402 of the compressed air nozzle 400 is less than 10 cm. However, a distance A of 6 cm to 3.5 cm is preferred, and even more preferably of 5 cm to 4 cm.
[0131] According to the invention, the opening diameter of the outlet opening 402 of the compressed air nozzle 400 is greater than 3 mm and is preferably 6 mm to 7 mm, most preferably 6.5 mm.
[0132] The compressed air nozzle 400 is supplied with compressed air by a compressed air generator 405. The compressed air nozzle 400 is designed to be switchable, for which purpose a solenoid valve 403 is provided. This valve is fluidically connected to the compressed air generator 505, on the one hand, via line 406, and to the compressed air nozzle 400, on the other hand, via line 404.
[0133] The structural separation of compressed air nozzle 400 and solenoid valve 403 makes it possible to use the installation space in the immediate vicinity of the laser device 140 in an optimized manner to position the compressed air nozzle 400 as close as possible to the laser beam 5, i.e. to select the distance A in the manner already described above.
[0134] Reference symbol
[0135] Spectrometer system 35 111 feeder
[0136] 3 Plasma 120 material part
[0137] 3A Plasma light 120A Aluminum part 5 Laser beam 120B Plastic part
[0138] 5A beam axis 130 slide
[0139] 7 Sample 40 131 upper section
[0140] 7A Surface 132 lower edge
[0141] 9 Laser beam source 140 Laser device 9A Optical fiber 150 Control device
[0142] 11 Focusing optics 160 sorting unit
[0143] 11A Focus zone 45 170 Collection point
[0144] 13 optical spectrometer 180 LIBS module
[0145] 13A Dispersive element 200 Conveyor 13B Detector 201 Feeding unit
[0146] 15 Evaluation unit 202 Feed unit
[0147] 17 spectral distribution 50 203 feed unit
[0148] 19 Entrance aperture 204 Feed area
[0149] 19A Inlet gap 205 Feed area 21 Detection unit 206 Feed area
[0150] 23 Lens mount 207 Transport direction
[0151] 25A lens 55 300 protective housing
[0152] 25B lens 301 air column
[0153] 25C Lens 302 Inner surface 25D Lens 303 Exit aperture
[0154] 27 Fiber optic system 400 compressed air nozzle
[0155] 29 optical input 60 401 direction of movement
[0156] 31 optical output 402 exit opening
[0157] 33 Measuring part 403 Solenoid valve 35 Detection cone 404 Line
[0158] 39 Plasma detection area 405 Air pressure generator
[0159] 41 Visibility 65 406 Line
[0160] 100 systems
[0161] 110 Feeding means Ch Inclination angle a2Inclination angle a3Inclination angle
Claims
Patent claims 1. 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) which is configured to feed the material part (120) to one of two fractions (F1, F2), a laser device (140) which is 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) which is configured to carry out a spectral analysis of a plasma light (3A) emitted by the laser-induced plasma (3) and to generate an output signal in accordance with a result of the spectral analysis carried out, and a control device (150) which is configured to receive the output signal and to control the sorting unit (160) based on the output signal and a to operate sorting criteria,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 an objective (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), wherein the feeding means (110) comprises three individual feeding units (201, 202, 203) arranged one behind the other in the transport direction (207) of the material part (120), wherein each feeding unit (201, 202, 203) is respectively configured to feed the material part (120) along a path provided by the respective feeding unit (201, 202, 203) Feed surface (204, 205, 206), wherein the feed surfaces (204, 205, 206) are each aligned inclined to the horizontal, forming a respective angle of inclination (ch, a2, a3), wherein the angles of inclination (OH, a2, a3) are formed differently,characterized in that the angle of inclination (ai) of the feed surface (204) of the in, Transport direction (207) of the first feed unit (201) is smaller than the angle of inclination (a2) of the feed surface (205) of the second feed unit (202) in the transport direction (207) and that the angle of inclination (a2) of the feed surface (205) of the second feed unit (202) in the transport direction (207) is smaller than the angle of inclination (a3) of the feed surface (206) of the third feed unit (203) in the transport direction (207).
2. System according to claim 1, characterized in that the difference between the angles of inclination (a l5 a2, a3) is 2° to 8°, preferably 3° to 7°, most preferably 5°.
3. System according to one of the preceding claims, characterized in that the angle of inclination (ai) of the feed surface (204) of the first feed unit (201) in the transport direction (207) is 7° to 13°, preferably 8° to 12°, most preferably 10°.
4. System according to one of the preceding claims, characterized in that the angle of inclination (a2) of the feed surface (205) of the second feed unit (202) in the transport direction (207) is 12° to 18°, preferably 13° to 17°, most preferably 15°.
5. System according to one of the preceding claims, characterized in that the angle of inclination (a3) of the feed surface (206) of the third feed unit (203) in the transport direction (207) is 17° to 23°, preferably 18° to 22°, most preferably 20°.
6. System according to one of the preceding claims, characterized in that the angles of inclination (a 1 ; a2, a3) are adjustable.
7. System according to one of the preceding claims, characterized in that the first feed unit (201) in the transport direction (207) is a vibratory conveyor with an unbalanced drive.
8. System according to one of the preceding claims, characterized in that the second and third feed units (202, 203) in the transport direction each have a Vibratory conveyors with a magnetic drive.
9. System according to one of the preceding claims, characterized in that the detection unit (21) has a further objective (25A, 25B, 25C, 25D), to which a further detection cone (35) is assigned, which forms a further plasma detection region (39) in a further overlap region (37) with the laser beam (5), wherein the objectives (25A, 25B, 25C, 25D) are arranged and / or aligned in relation to one another such that the plasma detection region (39) and the further plasma detection region (39) are offset along the beam axis (5A) and together form a field of view (41) of the detection unit (21). 10.System according to claim 1, characterized in that a plasma detection region (39) is configured such that, in the event of a plasma (3) present in the plasma detection region (39), a measurement portion (33) of the plasma light (3A) is detected by the associated lens (25A, 25B, 25C, 25D).
11. System according to one of the preceding claims, characterized in that the plasma detection regions (39) merge into one another or are arranged at a distance from one another along the beam axis (5A).
12. System according to claim 1 or 2, characterized in that the lens holder (23) provides an optical through-opening (43) through which the beam axis (5A) extends.System according to claim 1, characterized in that the sorting unit (160) is assigned to a lower edge (132) of the chute (130) opposite an upper section (131) of a chute (130), wherein the sorting unit (160) is designed to feed the material part (120) leaving the chute (130) via the lower edge (132) of the chute (130) to one of two fractions (F1, F2).
14. System according to one of the preceding claims, characterized in that the detection unit (21) carries a protective housing (300) which surrounds the laser beam (5) and the detection cone (34), wherein the protective housing (300). extends along the beam axis (5A).
15. System according to one of the preceding claims, characterized in that the sorting unit (160) has a compressed air nozzle (400) with an outlet opening diameter of greater than 3 mm, preferably from 5 mm to 8 mm, wherein the compressed air nozzle (400) is arranged at a distance from a laser beam (5) generated by the laser device (140) in the direction of movement (401) of a material part (120) passing through the laser beam (5), wherein the distance between the laser beam (5) and the center of the outlet opening (402) of the compressed air nozzle (400) is greater than 10 cm, preferably between 8 cm and 3 cm.