EP4324572A1 - System for analyzing and sorting a piece of material - Google Patents

Abstract

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 (110) for transporting the material part (120) - a sorting unit (160) which is set up to transport the material part (120). one of two fractions (F1, F2), - a laser device (140) which is set up to produce 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 set up 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 set up to receive the output signal and to operate the sorting unit (160) based on the output signal and a sorting criterion, - the spectrometer system (1) being a spectrometer (13) and a spectrometer (13) optically connected to the spectrometer (13). Detection unit (21), - wherein the detection unit (21) has a lens (25A, 25B, 25C, 25D), to which a detection cone (35) is assigned, which forms a plasma detection area in an overlap area (37) with the laser beam (5). (39), characterized in that the feed means (110) has three individual feed units (201, 202, 203) arranged one behind the other in the transport direction (207) of the material part (120), each feed unit (201, 202, 203 ) is each designed to transport the material part (120) along a feed surface (204, 205, 206) provided by the respective feed unit (201, 202, 203), the feed surfaces (204, 205, 206) each forming a respective Inclination angles (α₁, α₂, α₃) are aligned inclined to the horizontal, with the inclination angles (α₁ >, α₂, α₃) are designed differently.

Description

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 which is set up to feed the material part to one of two fractions, a laser device which is set up to to generate a plasma on a surface of the material part with a laser beam propagating along a beam axis, a spectrometer system which is set up to carry out 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 spectral analysis carried out, and a control device which is set up to receive the output signal and to operate the sorting unit based on the output signal and a sorting criterion, the spectrometer system having a spectrometer and a detection unit optically connected to the spectrometer, the detection unit having a lens to which a detection cone is assigned, which forms a plasma detection area in an overlap area with the laser beam.

A system of the type described above, ie of the generic type, is from the EP 3 352 919 B1 known. The previously known system enables material parts, in particular scrap parts made of aluminum, to be sorted on the basis of laser-induced plasma spectroscopy, also referred to as LIBS (laser-induced breakdown spectroscopy). Laser-induced plasma spectroscopy is used to determine an element-specific composition of a material part, ie a sample, using a plasma. The plasma is generated on a surface of the material part using high-intensity, focused laser radiation. Light imitated by the plasma is detected and spectrally evaluated in order to draw conclusions about the elemental composition of the material part.

According to the previously known system, material parts to be sorted are fed into a feed means. The feed means can be, for example, oscillating plates that provide a feed surface along which the material parts are moved.

The material parts to be analyzed and sorted are transported using the feed means according to the EP 3 352 919 B1 abandoned on a slide. Following gravity, the material pieces slide down the slide and leave it via a lower edge of the slide. From here, the material parts to be analyzed and sorted continue to move in free fall through the surrounding atmosphere, following the force of weight. The feed means and the chute ensure that the material parts are separated and moved through a spatially defined fall corridor in free fall.

During free fall, laser-induced plasma spectroscopy takes place for every piece of material leaving the slide. For this purpose, a laser device is provided which is designed to generate a plasma on a surface of a material part using a laser beam that propagates along a beam axis. Furthermore, a spectrometer system is provided which is set up to carry out 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 spectral analysis carried out.

This output signal is then used in combination with a sorting criterion in a sorting unit to feed 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. Certain material parts can be sorted out from the stream of material parts leaving the chute under the influence of air pressure. The result is a fraction of sorted material parts and a fraction of non-sorted material parts.

Typically, the previously known system serves to recognize parts of material of a certain composition and to separate them from parts of material of a different composition. Such a separation occurs either because a material part of an undesired composition is recognized and removed by means of the sorting unit or because the composition of a material part could not be reliably determined and therefore removal takes place by means of the sorting unit. The fraction of rejected material parts is therefore composed of material parts whose composition is clearly identified and not desired, on the one hand, and material parts whose composition is not clearly identified, on the other hand.

Although the system described above has proven itself in everyday practical use, there is a need for improvement. In particular, it has been found that, for an effective sorting result, it is crucial to feed the material parts to be sorted individually to the laser device and/or the spectrometer system, so that optimized access is made possible by the laser device and/or the spectrometer system in the further course of the process . Otherwise, the sorting result will be adversely affected, with material parts that are not clearly identified being sorted out in a disadvantageous manner.

It is therefore, based on the prior art described above, the object of the invention to further develop a system of the type mentioned at the beginning so that increased sorting efficiency is achieved.

To solve this problem, the invention proposes a system of the type mentioned at the beginning, which is characterized in that the feed means has three individual feed units arranged one behind the other in the transport direction of the material part, each feed unit being set up to feed the material part along one to transport the feed surface provided by the respective feed unit, the feed surfaces each being aligned inclined to the horizontal to form a respective angle of inclination, the angles of inclination being of different sizes.

According to the prior art, a feed means is used to transport the material part, which provides a feed surface along which the material part is moved in the 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 applied to the feed means so that they can then be fed to the laser device and/or the spectrometer system at a distance from one another.

However, the separation achieved with the previously known feed means is limited, which means that only a comparatively small throughput is possible. The throughput cannot be increased by adding more material parts to be sorted to the feed means, since in this case there will be insufficient separation, with the result that the sorting quality and thus also sorting efficiency decreases. The design according to the invention provides a remedy here.

The feed means according to the invention has at least three feed units. These are each designed as an independent assembly. There are therefore at least three separate, i.e. individual, feed units provided. These are arranged in a row one behind the other in the transport direction of the material part, which means that there is a first feed unit in the transport direction, a second feed unit in the transport direction and a third feed unit in the transport direction. Together, these feed units form the feed means according to the invention.

Each of the feed units is set up to transport the material part along a feed surface provided by the respective feed unit. Each feed unit therefore provides a feed area. When used as intended, the material part is conveyed in the transport direction and passed on from feed unit to feed unit.

The feed surfaces of the feed units are each aligned inclined to the horizontal, forming a respective angle of inclination. The feed units or their feed surfaces are therefore aligned obliquely, namely inclined to the horizontal in such a way that a material part is supported during its transport in the transport direction as a result of the effect of gravity.

The feed units each provide, for example, an oscillating plate that provides the respective feed surface. As a result of a swinging movement of such a plate, a piece of material located on it is transported in the transport direction. The inclined orientation 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.

According to the invention, it is further provided in this context that the angles of inclination of the feed surfaces are designed to be of different sizes. As a result, the different inclination angle formation means that the force of gravity acting on the material part has a different influence on the transport of the material part in the transport direction depending on the feed unit. The greater the angle of inclination, the greater the influence.

The different inclination angle design therefore advantageously ensures that a material part is accelerated to different degrees in the transport direction depending on the feed unit. This in turn advantageously allows a much more efficient separation of several material parts, even with a large number of material parts to be separated. The different inclination of the feed surfaces of the individual feed units ensures that the transport speed of the material parts increases as the transport distance increases, which means that the separation also increases as the transport distance increases. As a result, isolated material parts can be reliably fed to the laser device and/or the spectrometer system, even if, in contrast to the prior art, there are more material parts to be separated. The feed means according to the invention thus ensures an increased flow rate, and this at the same time as increasing the sorting quality, which means that the sorting efficiency of the system according to the invention is increased overall in contrast to the prior art.

According to a further feature of the invention, it is provided that the inclination angle of the feed surface of the first feed unit in the transport direction of the material part is smaller than the inclination angle of the feed surface of the second feed unit in the transport direction of the material part. Due to gravity, the material part is accelerated to a higher transport speed by means of the second feed unit. This leads to a separation of the material parts, particularly in the longitudinal direction of the feed unit, that is, in the transport direction of the material part.

The comparatively low transport speed, which is achieved by means of the first feed unit, serves in particular to separate the fed material parts in the width direction of the feed unit, that is, transversely to the transport direction of the material part. This measure ensures that the material parts fed in are evened out in the width direction, so that the sorting devices that the material parts pass through in the further process can be operated equally. In this way, it is advantageously avoided that individual sorting units are loaded with too many pieces of material in order to achieve a desired sorting quality, while other sorting units provide unused processing capacities. The first feed unit therefore serves to distribute the material parts over the overall available width of the feed means.

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, ensures a certain accumulation of the material parts in the transport direction. This build-up is resolved after the material parts have been transferred from the first feed unit to the second feed unit, since according to the invention the second feed unit is at a larger angle of inclination than the first feed unit. As a result of this, the material parts fed onto the second feed unit are separated in the longitudinal direction, that is to say in the transport direction of the material parts.

According to a further feature of the invention, it is provided that the inclination angle of the feed surface of the second feed unit in the transport direction of the material part is smaller than the inclination angle of the feed surface of the third feed unit in the transport direction of the material part.

Due to the even steeper inclination of the third feed unit compared to the second feed unit, a further acceleration of the material parts in the transport direction is achieved. The material parts that have already been pre-separated in the transport direction by means of the second feed unit are now pulled further apart in the transport direction by means of the third feed unit, and are therefore separated. In contrast to the prior art, this second separation stage in the longitudinal direction enables a higher number of material parts to be processed by the feed means. In this case, a separation in the width direction is carried out by means of the first feed unit and a separation in the longitudinal direction is carried out by means of the two further feed units, as a result of which isolated material parts are fed to the laser device or the spectrometer system in the longitudinal direction over the entire width of the feed means. In this way, spectroscopy as intended is also possible, in contrast to the prior art with an increased flow rate.

According to a further feature of the invention it is provided that the difference between the inclination angles is 2° to 8°, preferably 3° to 7°, most preferably 5°.

As studies have shown, the individual angles of inclination cannot be chosen completely freely. On the one hand, the angles must be steep enough for one of the Weight force following acceleration of the material parts can take place, especially in the longitudinal direction, to separate them. On the other hand, the angles must not be chosen too steep, otherwise the material will climb over and/or overtake effects, which contradicts the desired separation. According to the applicant's investigations, the angle ranges specified above are optimal, with a difference between the inclination angles of 5° being chosen in particular.

According to a further feature of the invention, it is provided that 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 choice of angle ensures that there is sufficient acceleration of the material parts fed to the feed unit in the transport direction, but at the same time the desired distribution of the material parts in the width direction takes place. An angle of inclination that is too steep would disadvantageously result in the desired distribution of the material parts in the width direction not being achieved.

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°.

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, specifically for the purpose of separating the material parts in the longitudinal direction of the feed unit, i.e. in the transport direction. The first step is to carry out pre-separation of the material parts, particularly while avoiding overtaking effects. An angle of inclination of 10° has proven to be particularly suitable for achieving this desirable separation. A particularly even steeper angle design would not lead to even greater isolation, but on the contrary would lead to partial, undesirable accumulations of material parts, in particular as a result of overhanging material parts and/or overtaking effects.

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°.

The material parts pre-separated using the second feed unit can now be further separated using the third feed unit. The further inclination with respect to the third feed unit is also possible while avoiding excess material and/or overtaking effects because the material parts are already pre-accelerated by means of the second feed unit. By means of the third feed unit, a further separation of the material parts takes place, so that ultimately material parts that are spaced apart in a defined manner leave the feed means in the direction of the laser device and/or the spectrometer system.

In contrast to the prior art, the three-stage nature of the feed means according to the invention allows, on the one hand, that an increased amount of material parts can be processed, while, on the other hand, uniform distribution in the width direction and separation in the transport direction is reliably guaranteed. The individual stages are coordinated with one another with regard to their respective angle of inclination in such a way that the material parts to be separated are further accelerated from stage to stage, i.e. from feed unit to feed unit, with undesirable overtaking effects and/or material parts exceeding each other being reliably avoided.

According to a further feature of the invention it is provided that the angles of inclination are designed to be adjustable. The ability to adjust the angle of inclination is particularly advantageous when different material parts can be sorted according to size and weight. This makes it possible, in particular, to be able to adjust 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 even individual feed units can be adjusted accordingly.

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

The first feed unit in the transport direction is used to separate the material parts or distribute them in the width direction. A vibratory conveyor with an unbalance drive is sufficient for this, so it is preferred because of its comparatively low purchase and maintenance costs.

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 unbalance drive, a vibratory conveyor with a magnetic drive offers the advantage of being able to dose continuously, which means that a more precise influence can be had on the conveying speed in the transport direction. The magnetic drive also ensures that there is no chance of material parts running over. As a result, this allows very precise control of the material transport, which can be used to specifically influence the desired separation of the material parts.

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, the objectives being arranged and/or aligned in relation to one another in this way that the plasma detection area and the further plasma detection area are arranged offset along the beam axis and together form a viewing area of the detection unit.

This configuration advantageously provides an enlarged detection range, with the result that more material parts can be reliably recognized with regard to their composition. As a result, the sorting result is improved because incorrect sorting is minimized. The result is sorting that is more effective.

The enlarged detection range results from the fact that, in contrast to the prior art, not just one lens is provided, but rather several lenses, i.e. at least two lenses. However, more than two lenses are preferred, for example three, four or even more lenses.

A plasma detection area is created for each lens. With four lenses, there are four plasma detection areas. According to the invention, it is now further provided that the lenses are arranged and/or aligned in relation to one another in such a way that the plasma detection areas are arranged offset along the beam axis of the laser beam and together form the viewing area of the detection unit. The viewing area represents the overall resulting detection area, which results from the individual plasma detection areas and is therefore significantly enlarged in contrast to the prior art.

According to the prior art, the detection area is formed by only one plasma detection area of a lens. Such a plasma detection area can typically extend over a distance of 8 to 10 mm along the beam axis of the laser beam. The inventive composition of the viewing area of the detection unit from individual plasma detection areas arranged offset along the beam axis leads to an overall detection area which has an extent of 20 mm, 30 mm, 40 mm or more in the direction of the beam axis. This advantageously ensures that material parts that would otherwise not be detectable can be reliably identified due to their geometric design, including in particular material parts that are spherical or partially spherical.

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

The inventive design of the feed means on the one hand and the equipment of the detection unit with an additional lens on the other hand result in the synergistic effect of an overall increased throughput. Although the feed means according to the invention may process more material parts in contrast to the prior art, it also requires a detection unit that is coordinated with this. On the other hand, a detection unit equipped with an additional lens is not fully utilized if the feed means is not able to provide a corresponding amount of material parts individually. The feed means designed according to the invention on the one hand and the further developed detection unit on the other hand, in combination, ensure an even further increased overall flow rate.

According to a further feature of the invention, it is provided that a plasma detection area is set up so that in the case of a plasma present in the plasma detection area, a measurement portion of the plasma light is detected by the associated lens. So if there is a laser-induced plasma in a plasma area, at least partially, a measurement portion of the emitted plasma light will be captured by the associated lens. If there are several lenses according to the invention, this means that the detection unit can detect plasma light in the form of measurement components of individual lenses.

According to a further feature of the invention, it is provided that the plasma detection areas merge into one another or are arranged at a distance from one another along the beam axis. Alternatively or additionally, the plasma detection areas can each extend over 1/10 to 1/4 of the viewing area along the beam axis. It is therefore possible, in particular after the sorting task, to form an overall detection area by appropriately arranging the plasma detection areas.

According to a further feature of the invention, it is provided that the feed means according to the invention for transporting the material part is set up to transport the material part along a feed surface up to an upper section of a slide. According to this preferred embodiment, the material part is fed into 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 piece reaches the chute, it moves down the chute following gravity. The purpose of the slide is, in particular, to align the material part and transfer it to a defined fall corridor.

According to a further feature of the invention, it is provided that the sorting unit is assigned to a lower edge of the slide opposite the upper section of the slide, the sorting unit being set up to feed the material part leaving the slide via the lower edge of the slide to one of two fractions.

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, in particular the laser device and the spectrometer system are arranged in the height direction below the lower edge of the slide.

Fig. 1

in schematischer Darstellung das erfindungsgemäße System;

Fig. 2

in schematischer Darstellung ein erfindungsgemäßes Zuführmittel;

Fig. 3

in einer weiteren schematischen Darstellung die Funktionsweise des erfindungsgemäßen Systems und

Fig. 4

in vergrößerter schematischer Darstellung das Spektrometersystem gemäß dem erfindungsgemäßen System nach Fig. 1.

Further features and advantages of the invention result from the following description based on the figures. Show it

Fig. 1

a schematic representation of the system according to the invention;

Fig. 2

a schematic representation of a feed means according to the invention;

Fig. 3

in a further schematic representation the functionality of the system according to the invention and

Fig. 4

in an enlarged schematic representation of the spectrometer system according to the system according to the invention Fig. 1 .

Fig. 1 shows the system 100 according to the invention in a schematic representation.

The system 100 is set up to subject a material part 120 to laser-induced plasma spectroscopy and to sort it depending on the result of the spectral analysis, with two fractions F1 and F2 being provided in the exemplary embodiment shown, to which the material part 120 can be assigned. Collection points 170, for example in the form of containers, are used to collect the respective fractions F1 and F2.

Like the schematic diagram Figure 1 can also be seen, the system 100 has a feed means 110 followed by a slide 130. When used as intended, a material part 120 is fed to the feed means 110. The feed means 110 is used to transport the material part 120 along a feed surface 111 provided by the feed means, namely 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 placed on the feed means 110 so that these can then be fed to the chute 130 at a further distance from one another.

A material part 120 transferred to the slide 130 slides following gravity Slide 130 down to the lower edge 132 of the slide, which is formed opposite the upper section 131 of the slide 130. It is in particular the task of the slide 130 to align the material part 120 and to transfer it into a defined fall corridor.

When leaving the slide 130, the material part 120 still moves under the influence of gravity in free fall through the surrounding atmosphere. This 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 a result of a spectral analysis carried out, 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 there is no deflection. In the event that there is no deflection, the material part 120 goes to the collection point 170 of the 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.

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 in Figure 1 is not shown in detail.

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 shown in particular using the exemplary embodiment Figure 2 can be recognized.

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

In the exemplary embodiment shown, the feed means 110 has three separate feed units 201, 202 and 203. These feed units are arranged in a row one behind the other in the transport direction 207 of the material part 120. Each feed unit 201, 202 and 203 each provides a feed surface 204, 205 and 206, along which a material part 120 is moved in the intended use.

The feed surfaces 204, 205 and 206 are each aligned inclined to the horizontal to form a respective angle of inclination α ₁ , α ₂ and α ₃ . According to the invention, the angles of inclination α ₁ , α ₂ and α ₃ are of different sizes.

In their entirety, the feed units 201, 202 and 203 form the feed means 110. The feed surface 111 provided by the feed means 110 is divided into the feed surfaces 204, 205 and 206 of the feed units 201, 202 and 203.

When used as intended, material parts 120 are fed to the feed means 110, for example by means of a conveyor 200, which can be designed as a belt conveyor.

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 unbalance drive and primarily serves to distribute the fed material parts 120 in the width direction, that is, transversely to the transport direction 207.

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

From the first feed unit 201, the material parts 120 then reach the second feed unit 202, which is connected 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 angle of inclination α ₂ which is larger than the angle of inclination α ₁ and is, for example, 15°. This steeper inclination angle α ₂ ensures that a higher transport speed of the material parts 120 in the transport direction 207 is achieved due to gravity. The result is that the material parts 120 are separated in the transport direction 207.

From the second feed unit 202, the material parts 120 finally reach the third Feed unit 203, the feed surface 206 of which is inclined to the horizontal at the angle of inclination α ₃ . The angle of inclination α ₃ is greater than the angle of inclination α ₂ of the second feed surface 205 and is, for example, 20°. Due to this even steeper angle of inclination α ₃ , a further acceleration of the material parts 120 takes place, which leads to an even higher speed of the material parts 120 with the result that even further separation takes place in the transport direction 207.

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

How in particular Figure 3 results, 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, which each forms a plasma detection area 39 in an overlap area with the laser beam 5. These plasma detection areas 39 are arranged offset from one another along the beam axis of the laser beam 5 and together form a viewing area 41 of the detection unit 21. The viewing area 41 is therefore composed of the individual plasma detection areas 39, which defines the detection area covered by the detection unit as a whole.

Fig. 3 shows a schematic overview of a spectrometer system 1 for the spectral analysis of a plasma light 3A emitted by a laser-induced plasma 3 (schematically indicated as a filled circle). Detectable plasma light 3A is, for example, in the wavelength range of UV light, visible light, near infrared light and/or infrared light; In particular, 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.

To generate the, e.g. B. pulsed, laser beam 5, the spectrometer system 1 includes a laser beam source 9. The laser beam source 9 is designed to provide laser beam parameters required for plasma generation. The laser beam 5 is z. B. fed via an optical fiber 9A to a focusing optics 11 and from there onto the surface 7A of the sample 7 (material part 120 according to Figure 1 ) focused. The focusing optics 11 can in particular be designed 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 laser beam 5 is propagated between the focusing optics 11 and the sample 7 along a beam axis 5A. Example focus diameters (1/e ² beam diameter in the beam waist) and focus lengths (double Rayleigh lengths) are in the range from <50 µm to >250 µm and in the range from <5 mm to >1,000 mm, respectively.

Laser parameters can in particular be set/selected such that an area in which plasma generation can take place (also referred to as an ignition area), 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, extends along the beam axis 5A.

Fig. 3 shows schematically a focus zone 11A elongated along the beam axis 5A, as 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, the usual dimensions (average diameter) of a plasma 3 are in the range of z. B. 0.1 mm to 5 mm (depending on sample material and laser parameters).

The spectrometer system 1 further includes an optical spectrometer 13 for spectral analysis of the plasma light 3A. The optical spectrometer 13 is in Fig. 2 shown as an example as a grid spectrometer. In general, the spectrometer 13 comprises at least one dispersive element 13A, e.g. B. a grid, a prism or a grating prism, and a pixel-based detector 13B, onto which the plasma light strikes 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, usually 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 and thus to the examined sample 3 and output them as the result of the spectral examination.

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

The spectrometer system 1 further comprises a detection unit 21 with a lens holder 23 and a plurality of lenses 25A, 25B, 25C, which are held by the lens holder 23. As an example, three lenses are shown in the figures, two in the image plane and one behind it. The number of lenses used can be selected depending on spatial and optical parameters as well as parameters of the material of the sample to be examined; it lies e.g. B. in the range from 2 to 20, for example with 4, 5, 8, 9 or 15 lenses.

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

Each of the lenses 25A, 25B, 25C is set up to capture a measurement portion 33 of the plasma light 3A and includes at least one focusing optical element, such as. B. 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 runs through the detection cones 35, the detection cones 35 having a set minimum size in the area of the laser beam 5. Each of the detection cones 35 includes a plasma detection area 39 in an overlap area with the laser beam 5, which is assigned to the corresponding objective 25A, 25B, 25C. For example, the detection cones 35 have a length from an entrance aperture of an objective to the laser beam in the range of 200 mm to 400 mm. An example is given in Fig. 2 the plasma 3 is generated in the plasma detection area 39 of the lens 25B, so that the associated measurement component 33 of the plasma light 3A is detected by the lens 25B and imaged onto the associated optical input 29 of the light guide system 27. Measurement components 33 detected 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.

Fig. 3 shows an example of three lenses 25A, 25B, 25C, which are arranged azimuthally distributed around the beam axis 5A. The lenses 25A and 25B lie on opposite sides of the beam axis 5A and are therefore from opposite ones Sides directed towards the beam axis 5A. The lens 25C is directed from behind onto the beam axis 5A. Another lens (in Fig. 2 not shown) can, for example, be directed from the front onto the beam axis 5A or, using a beam splitter, along the beam axis 5A onto the focus zone 11A. For clarification are in Fig. 2 the detection cones 35 are indicated by dashed lines 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.

Fig. 4 shows again a detailed view of the system 100 according to the invention Fig. 1 . It can be seen here that different material parts are provided in their composition, namely material parts 120B made of plastic and material parts 120A made of aluminum. In the manner already described, sorting can take place by means of the spectrometer system 1 according to the invention in such a way 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 sorting unit 160 removes it. For this purpose, the sorting unit 160 has an air pressure nozzle, by means of which a plastic part 120B can be removed 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 accumulate separately at the collection points 170.

Reference symbols

1

Spectrometer system

3

plasma

3A

Plasma light

5

laser beam

5A

beam axis

7

sample

7A

surface

9

Laser beam source

9A

Optical fiber

11

Focusing optics

11A

Focus zone

13

optical spectrometer

13A

dispersive element

13B

detector

15

Evaluation unit

17

spectral distribution

19

Entrance aperture

19A

Entry gap

21

Detection unit

23

Lens mount

25A

lens

25B

lens

25C

lens

25D

lens

27

Light guidance system

29

optical input

31

optical output

33

Measurement proportion

35

Detection cone

39

Plasma detection area

41

Viewing area

100

system

110

Feeding means

111

Feeding means

120

material part

120A

Aluminum part

120B

Plastic part

130

slide

131

upper section

132

bottom edge

140

Laser device

150

Control device

160

Sorting unit

170

Collection point

180

LIBS module

200

Sponsor

201

Feeding unit

202

Feeding unit

203

Feeding unit

204

feed area

205

feed area

206

feed area

207

Transport direction

α1

Angle of inclination

α2

Angle of inclination

α3

Angle of inclination

Claims (15)

System for analyzing and sorting a material part, in particular a scrap part made of aluminum, comprising: - a feed means (110) for transporting the material part (120) - a sorting unit (160) which is designed to feed the material part (120) to one of two fractions (F1, F2), - a laser device (140), which is set up 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 set up 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 set up to receive the output signal and to operate the sorting unit (160) based on the output signal and a sorting criterion, - wherein the spectrometer system (1) has a spectrometer (13) and a detection unit (21) optically connected to the spectrometer (13), - wherein the detection unit (21) has 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), characterized,
in that the feed means (110) has three individual feed units (201, 202, 203) arranged one behind the other in the transport direction (207) of the material part (120), each feed unit (201, 202, 203) being set up to feed the material part (120) along a feed surface (204, 205, 206) provided by the respective feed unit (201, 202, 203), the feed surfaces (204, 205, 206) each forming a respective inclination angle (α ₁ , α ₂ , (α ₃ ) are aligned inclined to the horizontal, with the angles of inclination (a ₁ , α ₂ , a ₃ ) being designed differently. System according to claim 1, characterized in that the angle of inclination (α ₁ ) of the feed surface (204) of the first feed unit in the transport direction (207). (201) is smaller than the angle of inclination (α ₂ ) of the feed surface (205) of the second feed unit (202) in the transport direction (207). System according to one of the preceding claims, characterized in that the inclination angle (α ₂ ) of the feed surface (205) of the second feed unit (202) in the transport direction (207) is smaller than the inclination angle (α ₃ ) of the feed surface (206) in the transport direction (202) 207) third feed unit (203) is formed. System according to one of the preceding claims, characterized in that the difference between the inclination angles (α ₁ , α ₂ , α ₃ ) is 2° to 8°, preferably 3° to 7°, most preferably 5°. System according to one of the preceding claims, characterized in that the angle of inclination (α ₁ ) 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 ° is. System according to one of the preceding claims, characterized in that the angle of inclination (α ₂ ) 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 ° is. System according to one of the preceding claims, characterized in that the angle of inclination (α ₃ ) 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 ° is. System according to one of the preceding claims, characterized in that the angles of inclination (α ₁ , α ₂ , α ₃ ) are designed to be adjustable. 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 unbalance drive. System according to one of the preceding claims, characterized in that the second and third feed units (202, 203) in the transport direction are each a vibratory conveyor with a magnetic drive. 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 is in a further overlap area (37) with the Laser beam (5) forms a further plasma detection area (39), the lenses (25A, 25B, 25C, 25D) being arranged and/or aligned in relation to one another in such a way that the plasma detection area (39) and the further plasma detection area (39) are along the Beam axis (5A) are arranged offset and together form a viewing area (41) of the detection unit (21). System according to claim 1, characterized in that a plasma detection area (39) is set up so that, in the event of a plasma (3) present in the plasma detection area (39), a measurement portion (33) of the plasma light (3A) is taken from the associated lens (25A, 25B , 25C, 25D). System according to one of the preceding claims, characterized in that the plasma detection areas (39) merge into one another or are arranged at a distance from one another along the beam axis (5A). System according to claim 3 or 4, characterized in that the lens holder (23) provides an optical through-opening (43) through which the beam axis (5A) runs. 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), the sorting unit (160) being designed to: 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).

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