System for analyzing and sorting material samples
A three-stage supply system with varying inclination angles and a multi-lens detection unit enhances sorting efficiency by ensuring uniform distribution and individualization, addressing throughput and quality issues in existing systems.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- HYDRO ALUMINUM RECYCLING DEUT GMBH
- Filing Date
- 2023-07-21
- Publication Date
- 2026-06-29
AI Technical Summary
Existing systems for sorting material pieces, particularly aluminum scrap, face challenges in achieving high sorting efficiency due to insufficient individualization of material pieces, leading to reduced throughput and sorting quality.
A three-stage supply system with varying inclination angles for each supply unit, combined with a detection unit equipped with multiple objective lenses and a protective housing, ensures efficient individualization and detection of material pieces, allowing for increased throughput and improved sorting quality.
The system achieves enhanced sorting efficiency by ensuring uniform distribution and individualization of material pieces, minimizing false sorting and enabling higher throughput rates while maintaining consistent sorting quality.
Smart Images
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Abstract
Description
Technical Field
[0003]
[0001] The present invention is a system for analyzing and sorting material pieces, particularly aluminum scrap pieces, comprising supply means for conveying the material pieces, a sorting unit designed to supply the material pieces to one of two fractions, a laser device designed to generate plasma on the surface of the material pieces using a laser beam propagating along a beam axis, a spectrometer system designed to perform spectral analysis of the plasma light emitted by the laser-induced plasma and generate an output signal according to the result of the performed spectral analysis, and a control device designed to receive the output signal and operate the sorting unit based on the output signal and sorting criteria. The spectrometer system comprises an optical spectrometer and a detection unit optically connected to the optical spectrometer. The detection unit has an objective lens, the objective lens has a detection cone assigned to itself, the detection cone forms a plasma detection area in an overlapping area with the laser beam. The supply means comprises three individual supply units arranged successively before and after in the conveying direction of the material pieces. Each supply unit is respectively configured to convey the material pieces along a supply surface provided by each supply unit. The supply surfaces are each inclined at respective inclination angles with respect to the horizontal, and the inclination angles are different. The system relates to this.
Background Art
[0002] A system for analyzing and sorting material pieces is known from Patent Document 1. The conventionally known system enables sorting of material pieces, particularly aluminum scrap pieces, based on laser-induced plasma spectroscopy, also called LIBS (Laser Induced Breakdown Spectroscopy). In this process, laser-induced plasma spectroscopy is used to determine the element-specific composition of the material pieces (i.e., samples) using plasma. The plasma is generated on the surface of the material pieces by high-intensity focused laser radiation. The light emitted by the plasma is detected and spectrally analyzed to estimate the elemental composition of the material pieces.
[0003] Furthermore, a device for sorting waste, particularly waste glass, according to its color, using a vibrating bar screen, a separation device, and a photoelectron measurement and sorting device is known from Patent Document 2.
[0004] A method and apparatus for sorting waste into different types of waste is known from reference 3. This apparatus comprises a first conveyor, a second conveyor, a third conveyor, an unloading means, an identification means, a recording and control means, and a means for separating the waste.
[0005] According to a system known from Patent Document 4, an apparatus for sorting bulk material, particularly pellets, comprises a vibrating conveyor system, a supply means for supplying bulk material to the vibrating conveyor system, a first outlet and a second outlet, a detector, and a sorting device that influences the trajectory of the bulk material so that bulk material recognized as defective falls to the second outlet, wherein a rotationally driven roller is adjacent to the end of the vibrating conveyor system, and bulk material conveyed beyond the end of the vibrating conveyor system reaches the roller, which conveys the bulk material toward the first outlet in a predetermined trajectory due to the rotation of the roller. It is suggested that one or more vibrating conveyor systems may comprise a plurality of vibrating conveyors arranged front to back in the direction of transport of the bulk material. Two or more of the plurality of vibrating conveyors may be arranged at different angles with respect to the horizontal.
[0006] According to the system known from Reference 1, the material pieces to be sorted are supplied to a supply means. The supply means may be, for example, a vibrating plate that provides a supply surface along which the material pieces move.
[0007] The material pieces to be analyzed and sorted are supplied to a chute by a supply means according to Patent Document 1. Due to gravity, the material pieces slide down the chute and exit the chute via its lower edge. From here, the material pieces to be analyzed and sorted continue to free-fall under gravity through the surrounding atmosphere. The supply means and chute function to individualize the material pieces and move them by free fall through spatially defined drop paths.
[0008] Laser-induced plasma spectroscopy is performed on each material piece exiting the chute during free fall. For this purpose, a laser device is provided that is configured to generate plasma on the surface of the material piece by a laser beam propagating along the beam axis. Furthermore, a spectrometer system is provided that is designed to perform spectral analysis of the plasma light emitted by the laser-induced plasma and to generate an output signal according to the results of the spectral analysis performed.
[0009] Next, this output signal is used in combination with a sorting criterion in a sorting unit to supply the material pieces exiting the chute to one of two fractions. For example, an air nozzle controlled accordingly by a control device can be used as the sorting unit. In this way, specific material pieces can be excluded from the flow of material pieces exiting the chute under the influence of air pressure. As a result, there is one fraction of sorted material pieces and one fraction of unsorted material pieces.
[0010] Typically, known systems are used to identify material pieces of a specific composition and separate them from material pieces of different compositions. Such separation occurs either because material pieces of an undesirable composition are identified and discharged by the sorting unit, or because the composition of a material piece cannot be reliably determined, and therefore discharge by the sorting unit occurs. A portion of the discharged material pieces consists, on the one hand, of material pieces whose composition is clearly identified and is undesirable, and on the other hand, of material pieces whose composition is not clearly identified.
[0011] While the above system has been demonstrated in everyday practical use, there is room for improvement. In particular, for effective sorting results, it has been found important that the material pieces to be sorted are fed into the laser device and / or spectrometer system in an individualized form, so that the laser device and / or spectrometer system can access them in an optimized manner as the process continues. Otherwise, the sorting results will be negatively affected, especially resulting in the unfavorable exclusion of material pieces that are not clearly identified. [Prior art documents] [Patent Documents]
[0012] [Patent Document 1] European Patent No. 3352919 [Patent Document 2] West German Utility Model Publication No. 9106292 Specification [Patent Document 3] International Publication No. 90 / 11142 [Patent Document 4] European Patent Application Publication No. 2859963 [Overview of the project] [Problems that the invention aims to solve]
[0013] Therefore, based on the prior art, the object of the present invention is to further develop the type of system initially described in terms of design in order to achieve high sorting efficiency. [Means for solving the problem]
[0014] To achieve this objective, the type of system mentioned at the beginning was proposed, and that system is The inclination angle of the supply surface of the first supply unit in the conveying direction is smaller than the inclination angle of the supply surface of the second supply unit in the conveying direction. The inclination angle of the supply surface of the second supply unit in the conveying direction is smaller than the inclination angle of the supply surface of the third supply unit in the conveying direction.
[0015] According to Patent Document 1, a feeding means is used to transport material pieces, and this feeding means provides a feeding surface along which the material pieces are moved in the intended use. The feeding means can be designed, for example, as a vibrating plate. In particular, the vibrating plate functions to individualize a plurality of material pieces fed onto the feeding means, so that the plurality of material pieces can then be fed at a distance from each other to a laser device and / or spectrometer system.
[0016] However, the individualization achieved by the supply means known from Patent Document 1 is limited, meaning that only relatively low throughput rates are possible. In this case, the throughput rate cannot be simply increased by supplying more material pieces to the supply means, as the individualization is insufficient, resulting in reduced sorting quality and therefore reduced sorting efficiency. The design according to the present invention provides a remedy here.
[0017] The supply means comprises three or more supply units. These are each designed as independent assemblies. Thus, three or more separate (i.e., individual) supply units are provided. These are arranged in a continuous front-to-back direction in the material piece transport direction, thereby having a first supply unit in the transport direction, a second supply unit in the transport direction, and a third supply unit in the transport direction. Together these supply units form the supply means according to the present invention.
[0018] Each supply unit is designed to transport material pieces along the supply surface provided by its respective supply unit. Thus, each supply unit provides a supply surface. In its intended use, material pieces are transported in the transport direction and passed from supply unit to supply unit.
[0019] The supply surfaces of the supply units are each inclined at respective inclination angles with respect to the horizontal. Thus, the supply units or their supply surfaces are inclined at an angle with respect to the horizontal so that the material pieces are supported while being conveyed in the conveying direction under the influence of gravity.
[0020] Each supply unit provides, for example, a plate that vibrates to provide respective supply surfaces. As a result of the vibrating movement of such a plate, the material pieces thereon are conveyed in the conveying direction. Since the gravity acting on the material pieces is added to the vibrating movement, the inclined alignment of each supply surface as provided in the present invention supports this conveyance.
[0021] In this case, it is also provided that the supply surfaces are designed to have different inclination angles. As a result of the different inclination angles, the gravity acting on the material pieces has different effects on the conveyance of the material pieces in the conveying direction depending on the supply unit. This effect increases as the inclination angle increases.
[0022] The different design of the inclination angles also has the advantageous effect of accelerating the material pieces to different extents in the conveying direction depending on the supply unit. Thereby, even when a large number of material pieces are individualized, it becomes possible to individualize a much larger number of material pieces much more efficiently. This is because the different angles of the supply surfaces of the individual supply units ensure that the conveying speed of the material pieces increases as the conveying distance increases, and this also increases the individualization efficiency as the conveying distance increases. As a result, the laser device and / or the spectrometer system can reliably supply the individualized material pieces even when the number of separated material pieces increases compared to the prior art. Therefore, the supply means according to the present invention ensures an increase in the flow rate while improving the sorting quality, whereby the sorting efficiency of the system according to the present invention is overall improved compared to the prior art.
[0023] According to the present invention, the inclination angle of the supply surface of the first supply unit in the conveying direction of the material piece is designed to be smaller than the inclination angle of the supply surface of the second supply unit in the conveying direction of the material piece. Due to gravity, the material piece is accelerated to a higher transport speed by the second supply unit. Thereby, particularly in the longitudinal direction of the supply unit, that is, in the conveying direction of the material piece, the individualization of the material piece is brought about.
[0024] The relatively low conveying speed achieved by the first supply unit functions to individualize the supplied material pieces particularly in the width direction of the supply unit, that is, in the transverse direction with respect to the conveying direction of the material piece. This means ensures the homogenization of the material pieces supplied in the width direction, so that the sorting devices through which the material pieces pass in further processes of the treatment can function equally. Particularly, this advantageously avoids supplying too many material pieces to an individual sorting unit for it to achieve the desired sorting quality while other sorting units are providing unused processing capacity. Therefore, the first supply unit is used to distribute the material pieces over the entire available width of the supply means.
[0025] The relatively low speed of the material pieces in the conveying direction provided by the first supply unit for the distribution in the width direction of the material pieces causes a certain accumulation of the material pieces in the conveying direction. This accumulation is eliminated after the material pieces are transferred from the first supply unit to the second supply unit because the second supply unit is inclined at a larger angle than the first supply unit. Thereby, the material pieces supplied onto the second supply unit are individualized in the longitudinal direction, that is, in the conveying direction of the material pieces.
[0026] According to the present invention, it is also provided that the inclination angle of the supply surface of the second supply unit in the conveying direction of the material piece is smaller than the inclination angle of the supply surface of the third supply unit in the conveying direction of the material piece.
[0027] The steeper incline of the third supply unit compared to the second supply unit achieves further acceleration of the material pieces in the transport direction. Material pieces already pre-individualized in the transport direction by the second supply unit are further separated and thus individuallyized by the third supply unit in the transport direction. This second stage of longitudinal individualization allows a larger number of material pieces to be processed by the supply means compared to the prior art. In this process, individualization in the width direction is performed by the first supply unit, and longitudinal individualization is performed by the two additional supply units, resulting in individually individualized material pieces being supplied longitudinally across the entire width of the supply means on the output side of the laser device or spectrometer system. This enables spectroscopy according to the intended purpose and allows for spectroscopy at increased flow rates, in contrast to the prior art.
[0028] According to another feature of the present invention, the difference between the inclination angles is 2° to 8°, preferably 3° to 7°, and most preferably 5°. As the study has shown, the individual inclination angles cannot be selected completely freely. On the one hand, the angle needs to be steep enough to allow the material piece to accelerate according to gravity, especially in the longitudinal portion, in order to individualize the material piece. On the other hand, the angle should not be selected to be too steep, because this will cause the material to step over and / or overtake, which contradicts the desired individualization. The aforementioned range of angles is optimal according to the applicant's study, and in particular, a difference of 5° between inclination angles is selected.
[0029] A further feature of the present invention is that the inclination angle of the supply surface of the first supply unit in the material piece conveying direction is 7° to 13°, preferably 8° to 12°, and most preferably 10°. This angle selection ensures that the material pieces supplied to the supply unit are sufficiently accelerated in the conveying direction, while at the same time ensuring that the desired distribution of material pieces in the width direction still occurs. An inclination angle that is too steep has the undesirable effect of hindering the desired distribution of material pieces in the width direction.
[0030] A further feature of the present invention is provided, in which the inclination angle of the supply surface of the second supply unit in the material piece conveying direction is 12° to 18°, preferably 13° to 17°, and most preferably 15°.
[0031] After the material pieces are transferred from the first supply unit to the second supply unit, they are accelerated in the transport direction for the purpose of individualizing the material pieces in the longitudinal direction of the supply unit, i.e., the transport direction. In the first step, it is important to perform pre-individualization of the material pieces, especially while avoiding the overtaking effect. A tilt angle of 10° has been shown to be particularly suitable for achieving this desired individualization. Steeper angles do not lead to greater individualization, but on the contrary, they lead to partial undesirable material accumulation, especially due to overtaking material pieces and / or the overtaking effect.
[0032] According to further features of the present invention, the inclination angle of the supply surface of the third supply unit in the material piece conveying direction is 17° to 23°, preferably 18° to 22°, and most preferably 20°.
[0033] Material pieces, pre-individualized by the second feeding unit, can now be further individualized by the third feeding unit. In this case, since the material pieces have already been pre-accelerated by the second feeding unit, further inclination toward the third feeding unit is also possible while avoiding material overtaking and / or overtaking effects. The third feeding unit also functions to further individualize the material pieces so that they eventually exit the feeding means and toward the laser device and / or spectrometer system, separated by a defined method.
[0034] In contrast to the prior art, the three-stage design of the feeding means according to the present invention allows for an increase in the amount of material pieces processed, on the one hand, and ensures uniform distribution in the width direction and individualization in the conveying direction. In this process, the individual stages are coordinated with respect to their respective inclination angles so that the individualized material pieces are further accelerated from stage to stage, i.e., from feeding unit to feeding unit, thereby ensuring that undesirable overtaking effects and / or overturned material pieces are avoided.
[0035] A further feature of the present invention is that the inclination angle is designed to be adjustable. The adjustability of the inclination angle is particularly advantageous when material pieces of different sizes and weights are being sorted. This is because it is particularly useful to be able to adjust each inclination angle by a method optimized for the sorting task. In this way, the inclination angles of all feeding units or only individual feeding units can be set as appropriate, particularly according to the size and / or specific weight of the material pieces being sorted.
[0036] A further feature of the present invention is that the first supply unit in the material piece conveying direction is an oscillating conveyor equipped with an unbalanced drive unit. The first supply unit in the conveying direction is used to individualize material pieces and distribute them in the width direction. A rocking conveyor with an unbalanced drive unit is sufficient for this purpose and is a preferred choice due to its relatively low acquisition and maintenance costs.
[0037] The second and third supply units are preferably designed as oscillating conveyors having magnetic drive units, according to further features of the present invention. In contrast to oscillating supply means having unbalanced drive units, oscillating supply means having magnetic drive units offer the advantage of being able to feed continuously, which means that a more precise influence can be exerted on the transport speed in the transport direction. The magnetic drive units also ensure that the following motion of the material pieces is essentially eliminated. This allows for very precise control of material transport, which means that a targeted influence can be exerted on the desired individualization of the material pieces.
[0038] According to another feature of the present invention, the detection unit comprises a further objective lens, the further objective lens having a further detection cone assigned to itself, the further detection cone forming a further plasma detection area in a further overlapping region with the laser beam, and the objective lens verbs are positioned relative to and / or aligned with each other such that the plasma detection area and the further plasma detection area are offset along the beam axis and together form the observation area of the detection unit.
[0039] This design advantageously provides an enlarged detection area, allowing for the reliable detection of more material fragments in terms of their composition. As a result, false sorting is minimized, improving sorting results. The result is a more efficient sorting process.
[0040] The expanded detection area is achieved not only by providing one objective lens, as in the conventional technology, but also by providing multiple objective lenses, i.e., two or more objective lenses. However, more than two objective lenses, for example, three, four or more objective lenses, are preferred.
[0041] A plasma detection area is set for each objective lens. Therefore, with four objective lenses, there are four plasma detection areas. The present invention further provides that the objective lenses are positioned relative to and / or aligned with each other such that the plasma detection areas are offset along the beam axis of the laser beam and together form the observation area of the detection unit. In this case, the observation area represents the entire detection area composed of the individual plasma detection areas and is therefore significantly larger than in the prior art.
[0042] In conventional technology, the detection area is formed by a single plasma detection area of the objective 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 configuration of the observation area of the detection unit according to the present invention, consisting of individual plasma detection areas offset along the beam axis, results in an overall detection area extending over 20 mm, 30 mm, 40 mm or more in the direction of the beam axis. This has the advantageous effect of reliably detecting undetectable material pieces, particularly spherical or partially spherical material pieces, due to their geometric design.
[0043] As a result, the system according to the present invention enables improved sorting because the proportion of excluded material pieces that are excluded because their composition cannot be reliably identified is minimized.
[0044] On the one hand, the design of the feeding means according to the present invention, and on the other hand, the equipping of a detection unit with additional objective lenses, result in a synergistic effect of increasing the overall throughput. The feeding means according to the present invention can process more material pieces than the prior art, but a detection unit adapted to this is also required. On the other hand, a detection unit with additional objective lenses is not fully utilized if the feeding means cannot individually deliver the corresponding amount of material pieces. Therefore, the feeding means designed according to the present invention and the further developed detection unit are combined to ensure an overall increase in flow rate.
[0045] A further feature of the present invention is provided, wherein the plasma detection area is configured such that, when plasma is present in the plasma detection area, the measurement component of the plasma light is detected by the associated objective lens. Thus, when laser-induced plasma is at least partially present in the plasma area, the measurement component of the emitted plasma light is detected by the associated objective lens. According to the present invention, if multiple objective lenses are present, this means that the detection unit can detect the plasma light in the form of the measurement component of each individual objective lens.
[0046] According to a further feature of the present invention, the plasma detection areas are arranged to be either integrated with or separated from each other along the beam axis. Alternatively, or in addition to this, each plasma detection area can extend over 1 / 10 to 1 / 4 of the observation area along the beam axis. Therefore, it is possible to form an entire detection region by arranging the plasma detection areas accordingly, particularly after a sorting task.
[0047] A further feature of the present invention provides that the supply means according to the present invention is configured to transport material pieces along a supply surface to the top of a chute. According to this preferred embodiment, material pieces are supplied to the supply means. From there, the material pieces pass through the chute and are transported along the supply surface of the supply means to the top of the chute. Once the material pieces reach the chute, they descend the chute by gravity. The purpose of the chute is, in particular, to align the material pieces and transport them to a defined drop path.
[0048] A further feature of the present invention is provided, wherein the sorting unit is associated with the lower edge of the chute opposite the upper portion of the chute, and the sorting unit is configured to direct material pieces exiting the chute through the lower edge to one of two fractions.
[0049] According to this preferred embodiment, the material pieces leave the chute by free fall and are analyzed and sorted in free fall. For this purpose, in particular, the laser device and spectrometer system are positioned vertically below the lower end of the chute.
[0050] A further feature of the present invention is provided that the detection unit is provided with a protective housing that surrounds the laser beam and the detection cone. A protective housing is provided to protect both the laser beam and the detection cone of the objective lens from the ingress of unwanted dust or particles from the outside. This effectively minimizes dust-related fluctuations in sorting efficiency and ensures that sorting efficiency remains at least constant over time.
[0051] The protective housing surrounds the laser beam and the detection cone. Thus, the laser beam and detection cone are guided through the volumetric space provided by the protective housing. Thanks to the encapsulation provided by the protective housing, this volumetric space contains very few foreign particles, particularly dust particles and / or similar contaminants, and as a result, neither the laser beam nor the detection cone has their functionality impaired. Furthermore, the protective housing advantageously ensures that dust or other foreign particles do not unintentionally accumulate, especially on the optical components, thus minimizing the risk of lens defects caused by such particles burning onto the lens.
[0052] Therefore, on the one hand, the protective housing ensures that the internal space volume provided by the protective housing and traversed by both the laser beam and the detection cone is kept virtually free of dust or similar foreign particles, and on the other hand, it ensures that dust or other foreign particles do not accumulate on the optical components or clog the passage openings. As a result, a sorting efficiency that is at least constant over time, even if not increasing, is guaranteed, and this is a structurally simple and therefore cost-effective method.
[0053] According to further features of the present invention, the protective housing extends along the beam axis of the laser beam. The protective housing is positioned on and therefore supported by the detection unit and extends from the detection unit in the direction of the longitudinal axis of the laser beam and therefore along the beam axis. The detection area of the laser beam and therefore the objective lens is also enclosed by the protective housing, and the protective housing provides reliable shielding from dust or other foreign particles to both the objective lens and the path of the laser beam.
[0054] According to a further feature of the present invention, the protective housing is provided to extend over a portion of the distance between the detection unit and the plasma detection area. The plasma detection area is located outside the protective housing. Otherwise, proper material detection would be impossible. To guide both the laser beam and the detection cone to the plasma detection area with as little dust or foreign particles as possible, the protective housing extends over at least a portion of the distance between the detection unit and the plasma detection area. However, the protective housing preferably extends to the plasma detection area so that the entire portion between the detection unit and the plasma detection area is covered by the protective housing as much as possible.
[0055] According to another feature of the present invention, the protective housing is a frustoconical pipe section. Thus, the protective housing is designed as a pipe that tapers on the plasma detection side. This taper has two advantageous effects. First, the protective housing is large enough on the detection unit side to completely accommodate the optical system provided by the detection unit on the one hand and the passage opening for the laser provided by the detection unit on the other hand. Thus, the entire optical system and the passage opening are covered by the protective housing and therefore protected from undesirable external influences.
[0056] As a result of the tapering of the protective housing in the direction of the plasma detection area, an exit opening is provided that is as small as possible, but still large enough so that the laser beam and detection cone are formed in the plasma detection area in the desired manner, i.e., not affected by the protective housing. In this case, the exit cross section of the protective housing is designed to be as small as possible to minimize undesirable dust or foreign particles entering the protective housing through the exit opening. In this case, the exit opening preferably has a diameter of 9 mm to 13 mm, preferably 10 mm to 12 mm, and more preferably 11 mm.
[0057] According to another feature of the present invention, the protective housing is provided to be connected to a compressed air supply source on the laser beam incidence side. The compressed air supply unit fills the protective housing with air, allowing the air to pass through the protective housing. In this process, air is supplied to the protective housing on the laser beam inlet side so that it passes through the protective housing in the direction of laser beam propagation and exits the protective housing through the outlet opening.
[0058] Air flushing of the protective housing has two main advantages. Firstly, any dust or other foreign particles that could enter the protective housing through the outlet opening are blown away by compressed air, so the protective housing is kept completely free of unwanted dust or foreign particles. On the other hand, on the outlet side, a column of air is formed around the laser beam. This also keeps the plasma detection area free of dust or other foreign particles, meaning that the laser beam can be used to access the material pieces to be sorted without dust particles. This optimizes laser detection and further improves the sorting efficiency of the system according to the present invention.
[0059] According to further features of the present invention, the protective housing is formed from a material that provides an inner surface that significantly reduces reflection. In particular, plastic is a suitable material because, unlike metal, it does not provide a glossy surface. Stray light penetrating the protective housing from the outside is absorbed to the greatest extent possible, and the effects of stray light do not impair the operation of the lens, thus optimizing the use of the lens.
[0060] A further feature of the present invention is that, in this case, the inner surface of the protective housing is roughened. The roughening ensures that any stray light effect that may occur results in diffuse reflection, which helps to maximize the light absorption rate. Thus, both the selection of materials and the design of the inner surface can be advantageously ensured to achieve a further increase in efficiency by avoiding any interference with the optical system due to stray light. Thus, the protective housing according to the present invention synergistically provides two effects: on the one hand, the effects of dust or other foreign particles are minimized, and on the other hand, the optical system is shielded from stray light. As a result of the design according to the present invention, not only can consistent sorting efficiency and quality be ensured over time, but there is also an improvement in sorting efficiency and quality, in contrast to the prior art. Thus, in contrast to the prior art, the system according to the present invention enables an increase in throughput.
[0061] A further feature of the present invention provides that the sorting unit has a compressed air nozzle having an outlet opening greater than 3 mm, wherein the compressed air nozzle is positioned at a distance from the laser beam generated by the laser device in the direction of movement of the material piece passing through the laser beam, and the distance between the laser beam and the center of the outlet opening of the compressed air nozzle is less than 10 mm.
[0062] The compressed air nozzle of the sorting device is used to implement material piece recognition performed by the detection unit, to which pressure is applied to the material piece identified by the input unit, and the identified material piece is discharged as a result of this pressure application. Compressed air nozzles used according to the prior art typically have an outlet opening diameter of 3 mm. Herein, the present invention proposes selecting a significantly larger outlet diameter, in any case greater than 3 mm.
[0063] Furthermore, the present invention provides that the distance between the compressed air nozzle and the laser beam is reduced to less than 10 cm, in contrast to the prior art. In the prior art, the distance between the laser beam and the compressed air nozzle is typically 10 cm or more.
[0064] In contrast to conventional techniques, the combination of an enlarged exit aperture diameter and an increased distance between the laser beam and the compressed air nozzle advantageously achieves an increased throughput of sorted material pieces.
[0065] With the typical drop velocity of the material pieces to be sorted and a nozzle opening time of 30 ms, as provided by conventional technologies, the material pieces to be sorted must be fed into the sorting unit at a distance of 9 cm or more for optimized sorting to occur. As soon as the distance between individual material pieces decreases to less than 9 cm, the individual material pieces are no longer cleanly collided with by the compressed air nozzle, resulting in a decrease in sorting quality.
[0066] The design according to the present invention provides a solution. On the one hand, the present invention provides, in contrast to the prior art, a reduction in the distance between the laser beam and the compressed air nozzle, i.e., the distance between the laser beam and the center of the outlet opening of the compressed air nozzle, to a distance of less than 10 cm. This reduction in distance ensures that material pieces free-falling toward the laser beam do not approach each other, which allows the material pieces to be individualized at the reduced distance. Since the fall distance is minimized by the reduction in distance, the fall time is also reduced, and as a result, the maintenance of the distance associated with the preceding individualization is not significantly altered by free fall in the direction of the laser device. As a result, the maintenance of the distance selected by the individualization of material pieces can be shortened, thereby enabling higher throughput.
[0067] As already described, individualization reduces the distance between individual material pieces, thus also reducing the switching time for the compressed air nozzle. This allows for an enlargement of the outlet opening diameter, in contrast to the conventional technology, resulting in a larger effective range for the compressed air nozzle. However, unlike the conventional technology, this increased effective range, in contrast to the conventional technology, reduces the switching time for the compressed air nozzle due to the reduced distance, so that adjacent material pieces that are not intended to be discharged are not discharged when compressed air is applied. However, enlarging the outlet opening diameter enables more reliable detection and thus enables the discharge of material pieces that are to be discharged, and as a result, combined with the two features of the present invention, a synergistic effect leads to both improved discharge quality and increased throughput. Consequently, sorting efficiency can be significantly increased, in contrast to the conventional technology.
[0068] According to prior art, it has been assumed that the outlet diameter of the compressed air nozzle should be as small as possible, i.e., 3 mm or less. This is to ensure that only the material being discharged is exposed to the compressed air, and that, for example, material adjacent to the discharged material is not exposed to the compressed air. It was not 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 increasing the outlet diameter of the compressed air nozzle makes it possible to decrease the distance between the laser beam and the compressed air nozzle. This is because reducing the distance between the compressed air nozzle and the laser beam minimizes the catch-up and / or overtake effect on material in free fall, and as a result there is no risk of capturing material adjacent to the discharged material despite the enlarged outlet diameter. However, an enlarged outlet diameter allows for more reliable capture of the discharged material, and as a result, in combination with the shortened distance between the compressed air nozzle and the laser beam, there is an increased throughput rate and improved sorting quality, in contrast to the prior art.
[0069] According to further features of the present invention, the diameter of the outlet opening is 5 mm to 8 mm, preferably 6 mm to 7 mm, and most preferably 6.5 mm. As the applicant's research has shown, the diameter of the exit aperture can be selected to be significantly larger than 3 mm. The size of the exit aperture diameter is optimized, on the one hand, depending on the distance between the compressed air nozzle and the laser beam, and on the other hand, depending on the material piece being sorted. In this regard, an exit aperture diameter of 6 mm to 7 mm is particularly preferred.
[0070] A further feature of the present invention is provided that 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, more preferably 5 cm to 4 cm, and most preferably 4.5 cm.
[0071] In contrast to the prior art, the reduction in the distance between the laser beam and the center of the compressed air nozzle's outlet opening brings about the advantages already mentioned. In this case, the applicant's research has shown that, in contrast to the prior art, this distance can be significantly reduced by correspondingly selected outlet opening diameters of the compressed air nozzles. The shorter the distance between the laser beam and the compressed air nozzle, the less likely it is that material pieces free-falling toward the laser beam will be caught or overtaken by each other. When the material pieces are sufficiently individualized, the distance between two consecutive material pieces is such that, when compressed air is applied to the compressed air nozzle to discharge one material piece, adjacent material pieces to the discharged material piece are not also caught. As a result, sorting quality is improved, as material pieces are not mistakenly discharged despite clear identification.
[0072] A further feature of the present invention is provided that the sorting unit comprises a solenoid valve cooperating with a compressed air nozzle, wherein the compressed air nozzle and the solenoid valve are arranged to be structurally separated from each other.
[0073] Structurally separating the compressed air nozzle and the solenoid valve allows for the optimization of the use of the available space very close to the laser device, so that the distance between the compressed air nozzle and the laser beam generated by the laser device in its intended use is as small as possible. Spatially separating the compressed air nozzle and the solenoid valve also has the advantage that the available space very close to the laser device is not unnecessarily wasted by accommodating the solenoid valve. Rather, this space remains open so that the compressed air nozzle can be optimally aligned to its distance from the laser device.
[0074] According to another feature of the present invention, the compressed air nozzle is fluidly connected to the solenoid valve by a compressed air line. Other conventional direct fluid connections between the compressed air nozzle and the solenoid valve are replaced, according to this proposal of the present invention, 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 without impairing the intended function of the compressed air nozzle.
[0075] A further feature of the present invention is that the switching time of the solenoid valve is less than 30 ms, preferably less than 20 ms, and more preferably less than 10 ms. In contrast to conventional technologies, this reduced switching time is made possible by the design according to the present invention, resulting in significantly higher throughput. Thus, twice or even three times the amount of material pieces can be sorted as intended per unit time.
[0076] Further features and advantages of the present invention will become apparent from the following description with reference to the accompanying drawings. [Brief explanation of the drawing]
[0077] [Figure 1] A schematic diagram of the system according to the present invention. [Figure 2] A schematic diagram of the supply means according to the present invention. [Figure 3] A further schematic diagram of the system operation according to the present invention. [Figure 4] An enlarged schematic diagram of the spectrometer system according to the present invention shown in Figure 1. [Figure 5] A further schematic diagram of the functionality of the LIBS module in the system according to the present invention. [Figure 6] A schematic side view of the cross-section of the module shown in Figure 5. [Figure 7] A partially cut side view of a protective housing according to the present invention. [Figure 8] A schematic diagram of a compressed air nozzle designed and arranged according to the present invention. [Modes for carrying out the invention]
[0078] Figure 1 schematically represents the system 100 according to the present invention. System 100 is configured to apply laser-induced plasma spectroscopy to material pieces 120 and sort the material pieces 120 according to the results of spectral analysis, and in the illustrated example, two fractions F1 and F2 are provided to which material pieces 120 can be assigned. A collection point 170 in the form of a bin functions to receive the respective fractions F1 and F2.
[0079] As can be seen from the schematic diagram in Figure 1, the system 100 has a feeding means 110 followed by a chute 130. In intended use, material pieces 120 are supplied to the feeding means 110. The feeding means 110 functions to transport the material pieces 120 along the feeding surface 111 provided by the feeding means, i.e., up to the top 131 of the chute 130. Here, the material pieces 120 are transferred from the feeding means 110 to the chute 130.
[0080] The supply means 110 is used, in particular, to individualize a plurality of material pieces 120 placed on the supply means 110, so that the plurality of material pieces 120 can be supplied to the chute 130 at a distance from each other.
[0081] The material pieces 120, transferred to the chute 130, slide down the chute 130 under gravity to the lower edge 132 of the chute, which is designed to face the upper edge 131 of the chute 130. The task of the chute 130 is, in particular, to align the material pieces 120 and transfer them into a defined drop path.
[0082] Once exiting the chute 130, the material piece 120 continues to move under the influence of gravity by free fall through the surrounding atmosphere. During this time, the material piece 120 passes through the spectrometer system 1. This ensures the analysis of the material piece 120, as will be described in more detail below. According to the results of the spectral analysis performed, the spectrometer system 1 generates an output signal. This is supplied to the control device 150, which operates, i.e., drives, the sorting unit 160, depending on this output signal on the one hand and on the other, on the other, on the sorting criteria. The sorting unit 160 either deflects the material piece 120 in free fall or does not deflect it. If no deflection occurs, the material piece 120 reaches the collection point 170 for fraction F2. Otherwise, if sorting by the sorting unit 160 occurs, the material piece 120 reaches the collection point 170 for fraction F1.
[0083] A spectrometer system 1, which is part of the LIBS module 180, is used to analyze the composition of a material piece 120. The LIBS module 180 also includes a laser device 140 and a control device 150. Preferably, the laser device 140, the spectrometer system 1, and the control device 150 are housed in a common housing not shown in detail in Figure 1.
[0084] The laser device 140 itself consists of further individual components, such as a laser beam source 9, an optical fiber 9A, and a focusing optical system 11, as can be seen particularly from the example shown in Figure 2.
[0085] As can be seen from the illustration in Figure 2, the supply means 110 is designed in three stages according to the present invention. In the example shown, the supply means 110 has three separate supply units 201, 202, and 203. These supply units are arranged consecutively front to back in the transport direction 207 of the material piece 120. Each supply unit 201, 202, and 203 provides a supply surface 204, 205, and 206, respectively, along which the material piece 120 moves in its intended use.
[0086] The supply surfaces 204, 205, and 206 are inclined with respect to the horizontal at inclination angles α1, α2, and α3, respectively. The inclination angles α1, α2, and α3 are designed to be of different sizes according to the present invention.
[0087] Overall, the supply units 201, 202, and 203 form the supply means 110. The supply surface 111 provided by the supply means 110 is subdivided into the supply surfaces 204, 205, and 206 of the supply units 201, 202, and 203.
[0088] In its intended use, the supply means 110 is supplied with material pieces 120 by a conveyor 200, which may be designed as, for example, a belt conveyor. From the conveyor 200, the material pieces 121 reach the first supply unit 201 in the transport direction 207. This supply unit 201 is designed, for example, as a vibrating conveyor with an unbalanced drive unit and is mainly used to distribute the supplied material pieces 120 in the width direction, i.e., laterally with respect to the transport direction 207.
[0089] The supply surface 204 of the first supply unit 201 is inclined at an angle α1 of, for example, 10°. As a result, the material pieces are transported in the transport direction 207 by gravity. Next, the material pieces move from the first supply unit 201 to the second supply unit 202, which is located downstream of the first supply unit 201 in the transport direction 207. The supply surface 205 provided by the second supply unit 202 is at an inclination angle α2 that is greater than the inclination angle α1, for example, 15°. This steeper inclination angle α2 ensures that a higher transport speed of the material pieces 120 in the transport direction 207 is achieved by gravity. As a result, the material pieces 120 are individualized in the transport direction 207.
[0090] From the second supply unit 202, the material pieces 120 eventually reach the third supply unit 203, whose supply surface 206 is inclined at an angle α3 with respect to the horizontal. The angle α3 is greater than the angle α2 of the second supply surface 205, for example, 20°. This steeper angle α3 causes further acceleration of the material pieces 120, which results in a higher velocity for the material pieces 120, and consequently, further individualization occurs in the conveying direction 207.
[0091] Finally, the material pieces 120 are individualized in the transport direction 207 so that they enter the chute 130 after passing through the supply unit 203, and as a result, sorting can be performed by the method already described.
[0092] As can be seen particularly in Figure 3, the spectrometer system 1 has a detection unit 21, which serves several purposes. Detection cones 35 are assigned to each of these objective lenses and in each case form a plasma detection area 39 in the area overlapping with the laser beam 5. These plasma detection areas 39 are offset from each other along the beam axis of the laser beam 5 and together form the observation area 41 of the detection unit 21. Thus, the observation area 41 is composed of the individual plasma detection areas 39, thereby defining the detection area that is covered overall by the detection unit.
[0093] Figure 3 shows a schematic overview of the spectrometer system 1 for spectral analysis of plasma light 3A emitted by laser-induced plasma 3 (circularly shown as black circles). Detectable plasma light 3A is in the wavelength range of, for example, UV, visible, near-infrared, and / or infrared light, and in particular, detectable plasma light can be in the spectral range of approximately 190 nm to approximately 920 nm. In the case of LIBS, plasma 3 is generated by a laser beam 5 on the surface 7A of the sample 7.
[0094] For example, to generate a pulsed laser beam 5, the spectrometer system 1 includes a laser beam source 9. The laser beam source 9 is designed to provide the laser beam parameters necessary for plasma generation. The laser beam 5 is supplied, for example, through an optical fiber 9A of a focusing optical system 11, which focuses it onto the surface 7A of the sample 7 (material piece 120 in Figure 1). The focusing optical system 11 may be designed as a laser head component with a particular focusing function, such as an active laser component having a focusing function that acts particularly on the spectrum or pulse duration or pulse energy. The laser beam 5 propagates between the focusing optical system 11 and the sample 7 along the beam axis 5A. Exemplary focal diameters (1 / e2 beam diameter at the beam waist) and focal lengths (twice the Rayleigh length) are in the range of <50 μm to >250 μm or <5 mm to >1000 mm, respectively.
[0095] In particular, the laser parameters may be set / selected so that the range over which plasma generation can occur (also called the ignition range) extends along the beam axis 5A, for example, over a length of approximately 5 mm to approximately 50 mm, or over a length of 10 mm, 20 mm, or 30 mm.
[0096] Figure 3 schematically shows an elongated focal zone 11A along the beam axis 5A, formed in an area of the surface 7A of sample 7. Plasma 3 is formed by the interaction between the laser radiation and the material on the surface of sample 7A. In LIBS, the typical dimensions (average diameter) of plasma 3 are in the range of, for example, 0.1 mm to 5 mm (depending on the sample material and laser parameters).
[0097] The spectrometer system 1 also includes an optical spectrometer 13 for spectral analysis of plasma light 3A. The optical spectrometer 13 is shown in Figure 2 as an example of a grating spectrometer. Generally, the spectrometer 13 comprises one or more dispersion elements 13A, e.g., a grating, a prism, or a grating prism, and a pixel-based detector 13B into which the plasma light is incident in a spectrally extended form. The spectral components of the plasma light 3A to be analyzed are assigned to pixels of the detector 13B. The detector 13B outputs the intensity values of the irradiated pixels to an evaluation unit 15, which is usually a computer having a processor and memory. The evaluation unit 15 outputs the measured spectral distribution 17, compares it to, for example, a stored reference spectrum, assigns the elements contributing to the plasma light 3A to the plasma light 3A and therefore to the sample 3 being examined, and outputs them as the results of the spectral examination.
[0098] In the spectrometer 13, the (spectrum-dependent) beam inlet for the plasma light to be analyzed is defined by the inlet aperture 19, usually by the inlet slit 19A. The spectrometer system 1 further comprises a detection unit 21 having an objective lens holder 23 and several objective lenses 25A, 25B, 25C supported by the objective lens holder 23. As an example, three objective lenses are shown in the figure, two in the image plane and one behind them. The number of objective lenses used can be selected depending on the spatial and optical parameters as well as the material parameters of the sample being inspected, and ranges from 2 to 20, for example, 4, 5, 8, 9, or 15 objective lenses.
[0099] The spectrometer system 1, in particular the detection unit 21, further comprises an optical fiber system 27 that optically connects the objective lenses 25A, 25B, and 25C to the spectrometer 13. The optical fiber system 27 provides several optical inputs 29, each optically assigned to one of the objective lenses 25A, 25B, and 25C, and an optical output 31 (functional and common to the objective lenses) optically assigned to the inlet aperture 19.
[0100] Each of the objective lenses 25A, 25B, and 25C is configured to detect the measurement component 33 of the plasma light 3A and comprises one or more focusing optical elements such as a focusing lens or a concave mirror. A detection cone 35 is assigned to each of the objective lenses 25A, 25B, and 25C. The beam axis 5A extends through the detection cone 35, which has a set minimum size in the region of the laser beam 5. Each of the detection cones 35 encompasses a plasma detection area 39 in the overlapping region with the laser beam 5, and this plasma detection area 39 is assigned to the corresponding objective lens 25A, 25B, and 25C. For example, the detection cone 35 has an entrance aperture length of the objective lens relative to the laser beam in the range of 200 mm to 400 mm. As an example, in Figure 2, plasma 3 is generated in the plasma detection area 39 of the objective lens 25B such that the associated measurement component 33 of the plasma light 3A is detected by the objective lens 25B and imaged onto the associated optical input 29 of the optical fiber system 27. The measurement component 33 captured by one or more objective lenses is directed by the optical light guide system 27 to a common optical output 31 and coupled to the optical spectrometer 13 through the inlet aperture 19 for spectral analysis.
[0101] Figure 3 shows, as an example, three objective lenses 25A, 25B, and 25C, which are azimuthally dispersed around the beam axis 5A. Objective lenses 25A and 25B are on either side of the beam axis 5A and are therefore directed toward the beam axis 5A from both sides. Objective lens 25C is directed toward the beam axis 5A from the rear. Another objective lens (not shown in Figure 2) can be directed, for example, toward the beam axis 5A from the front, or toward the focal zone 11A along the beam axis 5A using a beam splitter. For clarity, the detection cone 35 is shown in Figure 2 as extending conically relative to the beam axis 5A, and the focal zone 11A, plasma 3, and plasma detection area 39 are shown larger relative to the detection cone 35 for clarity.
[0102] Figure 4 again shows a detailed diagram of the system 100 according to the present invention according to Figure 1. Here, it can be seen that material pieces of different compositions are provided, namely plastic material pieces 120B and aluminum material pieces 120A. As already described, the spectrometer system 1 according to the present invention can be used to separate material pieces 120A from material pieces 120B. For this purpose, the sorting unit 160 discharges the plastic material pieces 120B if they are detected. For this purpose, the sorting unit 160 has a pneumatic nozzle 400 which can discharge the plastic pieces 120B from the material piece flow. As a result of such sorting, the plastic material pieces 120B and aluminum material pieces 120A are accumulated separately at the collection point 170.
[0103] Figure 4 shows the mounting plate 23A of the detection unit 21 of the LIBS system to clarify the arrangement and orientation of the objective lenses 25A, 25B, and 25C. To securely mount the objective lenses, the mounting plate 23A has objective lens holding holes for receiving the objective lenses 25A, 25B, and 25C. Each objective lens holding aperture is positioned radially away from the beam axis 5A and designed to orient the objective lenses 25A, 25B, and 25C obliquely with respect to the beam axis 5A.
[0104] As shown in Figure 4, the plasma detection area 39 together forms the observation area 41 of the detection unit 21. The observation area 41 extends along the beam axis 5A in the region of the focal zone 11A.
[0105] Furthermore, in the mounting plate 23A shown in Figure 2, an optical passage opening 43 is visible, which is used to direct the laser beam through the holder 23 and the objective lenses 25A, 25B, and 25C onto the sample 7.
[0106] Figure 5 shows a perspective view of an exemplary LIBS measurement head connected to a laser beam source via an optical fiber 9A. The holder 23 of the LIBS measurement head includes a longitudinal support plate 23B on which fixtures for the optical fiber 9A and the focusing optical system 11 (a laser head with beam shaping) are provided on the input side. Furthermore, the optical spectrometer 13 is mounted on the longitudinal support plate 23B and includes a mounting plate 23A for four objective lenses 25A, 25B, 25C, and 25D (typically an input optical system with n > 1 times). The objective lenses 25A, 25B, 25C, and 25D are designed to detect measurement components of plasma light from plasma detection areas 39, which are offset from each other along the beam axis 5A, and to supply them to the spectrometer 13 for spectral analysis via an optical fiber system 27 (e.g., a fiber bundle with n > 1 inputs and 1 functional output - "n-to-1 fiber bundle"). As an example, Figure 3 shows the optical fiber 45 of the optical fiber system 27 that optically connects the objective lens to the common spectrometer 13. Using the optical fiber system 27, measurement components in the spectrometer 13 (or optionally before coupling to the spectrometer 13) can be combined for measurement processing.
[0107] Figure 6 shows a schematic side view of a part of the module shown in Figure 5, and the mounting plate 23A is equipped with the protective housing 300 according to the present invention. As can be seen from the diagram in Figure 6, the protective housing 300 is a frustoconical tube. It extends along the beam axis 5A of the laser beam 5, starting from the mounting plate 23A and continuing to the observation area 41, i.e., to the first plasma detection area 39 in the propagation direction of the laser beam 5. The protective housing 300 substantially bridges the distance between the plasma detection area 39 and the mounting plate 23A in the longitudinal direction of the laser beam 5.
[0108] The protective housing 300 surrounds both the laser beam 5 and the detection cones 35 assigned to the objective lenses 25A to 25D, respectively. Thus, the laser beam 5 and the detection area 35 are enclosed by the protective housing 300.
[0109] The protective housing 300 essentially achieves two effects. Firstly, the lenses 25A-25D, as well as the light-passing aperture 43 formed in the mounting plate 23A for the laser beam 5, are protected from the undesirable influence of dust and / or other foreign particles from the environment. This significantly prevents undesirable influence of dust and / or other foreign particles on the lenses 25A-25D and the passage aperture 43.
[0110] On the other hand, the volumetric space provided by the protective housing 300, which is traversed by both the laser beam 5 and the detection cone 35 in their intended use, is also kept free of dust and / or other foreign particles, so that both the laser beam 5 and the detection cone 35 do not have their intended functions impaired.
[0111] The protective housing 300 is connected to a compressed air unit, which is not specifically shown in the figure. This unit supplies compressed air to the protective housing 900 on the mounting plate side, and this compressed air flows through the protective housing 300 in the direction of propagation of the laser beam 5. As a result of such airflow, any dust and / or other foreign particles are effectively prevented from entering the protective housing 300 through the outlet opening 303 on the plasma detection side of the protective housing 300.
[0112] Applying air to the protective housing 300 also has the advantage that an air cone or air column 301 surrounding the laser beam 5 is formed on the exit side of the protective housing 300. This also has the positive effect that the observation area 41, which consists of the plasma detection area 39, is kept as free of dust and / or other foreign particles as possible.
[0113] Figure 7 shows details of the protective housing 300 according to the present invention in a partially cut side view. In particular, as can be seen from this figure, the protective housing 300 is frustoconical and provides an outlet opening 303 on the output side. This preferably has a circular cross-section and is traversed through the center by the laser beam 5.
[0114] The protective housing 300 is preferably made of plastic having minimal or no reflective properties. Stray light entering the protective housing 200 through the exit opening 303 is absorbed to the extent that the optical system covered by the protective housing 300 is not affected by reflected stray light. In this case, it is also intended that the inner surface 303 of the protective housing 200 be roughened. This results in diffuse reflection of stray light penetrating the protective housing and helps to minimize undesirable interference with the lenses 25A-25D covered by the protective housing 300.
[0115] Figure 8 shows, in general terms, the design and arrangement of the compressed air nozzle 400 according to the present invention. As can be seen from Figure 8, the compressed air nozzle 400 is positioned at a distance from the laser beam 5 generated by the laser device 140 in the direction 401 of movement of the material piece 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 a distance of 5 cm to 4 cm is even more preferred.
[0116] According to the present invention, the diameter of the outlet opening 402 of the compressed air nozzle 400 is greater than 3 mm, preferably 6 mm to 7 mm, and most preferably 6.5 mm. Compressed air is supplied to the compressed air nozzle 400 from the compressed air generator 405.
[0117] The compressed air nozzle 400 is designed to be switchable, for which a solenoid valve 403 is provided. This valve is fluidly 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.
[0118] By structurally separating the compressed air nozzle 400 and the solenoid valve 403, it becomes possible to optimally utilize the immediate installation space of the laser device 140 in order to position the compressed air nozzle 400 as close as possible to the laser beam 5, i.e., to select distance A as already described. [Explanation of symbols]
[0119] 1. Spectrometer System 3 Plasma 3A Plasma Light 5. Laser beam 5A Beam axis 7 samples 7A surface 9. Laser beam source 9A optical fiber 11 Focusing optical system 11 Focal Zones 13 Optical spectrometer 13A Dispersion element 13B detector 15 evaluation units 17. Spectral distribution 19 Entrance opening 19A Inlet gap 21 detection units 23 Objective lens holder 25A objective lens 25B objective lens 25C objective lens 25D objective lens 27 Fiber Optic System 29 Optical input 31 Light output 33 measuring components 35 detection cones 39 Plasma detection area 41 Observation Area 100 Systems 110 Means of supply 111 Supply means 120 Material Piece 120A Aluminum part 120B Plastic part 130 shots 131 Top 132 Lower edge 140 Laser Devices 150 control devices 160 sorting units 170 Accumulation points 180 LIBS module 200 conveyors 201 Supply Unit 202 supply units 203 Supply Unit 204 Supply side 205 Supply side 206 Supply side 207 Conveying direction 300 protective housing 301 Air column 302 Inner Self 303 Exit opening 400 Compressed Air Nozzles 401 Direction of movement 402 Exit opening 403 Solenoid valve 404 Line 405 Compressed air generator 406 Line α1 tilt angle α2 tilt angle α3 tilt angle
Claims
1. A system for analyzing and sorting material pieces, A supply means (110) for transporting the material piece (120), A sorting unit (160) is configured to supply the material piece (120) to one of two fractions (F1, F2), A laser device (140) is configured to generate plasma (3) on the surface (7A) of the material piece (120) using a laser beam (5) that propagates along the beam axis (5A), A spectrometer system (1) is configured to perform spectral analysis of plasma light (3A) emitted by the laser-induced plasma (3) and to generate an output signal according to the results of the spectral analysis, The system includes a control device (150) configured to receive the output signal and operate the sorting unit (160) based on the output signal and sorting criteria, The spectrometer system (1) comprises an optical spectrometer (13) and a detection unit (21) optically connected to the optical spectrometer (13), The detection unit (21) has objective lenses (25A, 25B, 25C, 25D), each of which has a detection cone (35) assigned to it, and the detection cone (35) forms a plasma detection area (39) in the overlapping region (37) with the laser beam (5). The supply means (110) comprises three individual supply units (201, 202, 203) as a first supply unit (201), a second supply unit (202), and a third supply unit (203), which are arranged continuously front to back in the transport direction (207) of the material pieces (120). Each supply unit (201, 202, 203) is configured to transport the material pieces (120) along the supply surfaces (204, 205, 206) provided by each of the supply units (201, 202, 203), The supply surfaces (204, 205, 206) are each inclined with respect to the horizontal, and their respective inclination angles (α １ , α ２ , α ３ ) form, The inclination angle (α １ , α ２ , α ３ ) are designed to be different, The inclination angle (α) of the supply surface (204) of the first supply unit (201) in the transport direction (207) １ ) is the inclination angle (α) of the supply surface (205) of the second supply unit (202) in the transport direction (207). ２ It is designed to be smaller than ) The inclination angle (α ２ ) of the supply surface (205) of the second supply unit (202) in the transport direction (207) is ３ configured to be smaller than the inclination angle (α ) of the supply surface (206) of the third supply unit (203) in the transport direction (207).
2. The inclination angle (α １ , α ２ , α ３ The system according to claim 1, wherein the difference between the two is 2° to 8°.
3. The inclination angle (α) of the supply surface (204) of the first supply unit (201) in the transport direction (207) １ The system according to claim 1 or 2, wherein the angle is between 7° and 13°.
4. The inclination angle (α) of the supply surface (205) of the second supply unit (202) in the transport direction (207) ２ The system according to claim 1 or 2, wherein the angle is between 12° and 18°.
5. The inclination angle (α) of the supply surface (206) of the third supply unit (203) in the transport direction (207) ３ The system according to claim 1 or 2, wherein the angle is 17° to 23°.
6. The inclination angle (α １ , α ２ , α ３ The system according to claim 1 or 2, wherein the element is designed to be adjustable.
7. The system according to claim 1 or 2, wherein the first supply unit (201) in the conveying direction (207) is a vibrating conveyor having an unbalanced drive unit.
8. The system according to claim 1 or 2, wherein the second supply unit (202) and the third supply unit (203) in the conveying direction are each oscillating conveyors having magnetic drive units.
9. The detection unit (21) comprises further objective lenses (25A, 25B, 25C, 25D), each of which has further detection cones (35) assigned to the further objective lenses (25A, 25B, 25C, 25D), and each of which forms further plasma detection areas (39) in further overlapping regions (37) with the laser beam (5). The system according to claim 1 or 2, wherein the further objective lenses (25A, 25B, 25C, 25D) are positioned relative to each other, aligned, or both, such that the plasma detection area (39) and the further plasma detection area (39) are offset along the beam axis (5A) and together form the observation area (41) of the detection unit (21).
10. The system according to claim 1, wherein the plasma detection area (39) is configured such that when plasma (3) is present in the plasma detection area (39), the plasma light (3A) measurement component (33) is detected by the associated objective lenses (25A, 25B, 25C, 25D).
11. The system according to claim 1 or 2, wherein the plasma detection areas (39) are arranged to be either integrated with each other or spaced apart from each other along the beam axis (5A).
12. The system according to claim 1 or 2, wherein the objective lens holder (23) provides an optical passage opening (43) through which the beam axis (5A) extends.
13. The system according to claim 1, wherein the sorting unit (160) is assigned to the lower edge (132) of the chute (130), the lower edge (132) is on the opposite side of the upper part (131) of the chute (130), and the sorting unit (160) is configured to supply the material pieces (120) that have left the chute to one of two fractions (F1, F2) via the lower edge (132) of the chute (130).
14. The system according to claim 1 or 2, wherein the detection unit (21) carries a protective housing (300) surrounding the laser beam (5) and the detection cone (35), and the protective housing (300) extends along the beam axis (5A).
15. The sorting unit (160) comprises a compressed air nozzle (400) having an outlet opening diameter greater than 3 mm, wherein the compressed air nozzle (400) is positioned at a distance from the laser beam (5) generated by the laser device (140) in the direction (401) of movement of the material piece (120) passing through the laser beam (5), and the distance between the laser beam (5) and the center of the outlet opening (402) of the compressed air nozzle (400) is less than 10 cm, the system according to claim 1 or 2.