WO2017109035A1

WO2017109035A1 - Sorting pieces of raw material

Info

Publication number: WO2017109035A1
Application number: PCT/EP2016/082305
Authority: WO
Inventors: Philipp Soest
Original assignee: ProASSORT GmbH
Priority date: 2015-12-22
Filing date: 2016-12-22
Publication date: 2017-06-29
Also published as: DE102015122570A1; DE102015122570B4

Abstract

The invention relates to a method for sorting pieces of raw material (5) which undergo a sensory analysis, preferably a spectroscopic analysis, of the composition. The pieces of raw material (5) are brought onto a conveyor belt (1) moving in a conveyor direction (2), the sensory analysis is carried out, and the pieces of raw material (5) are sorted transversely to the conveyor direction (2) of the conveyor belt (1) into individual target fractions (13) on the basis of the ascertained composition of the pieces of raw material (5) by applying gas pressure pulses (11), preferably compressed air pulses, or mechanical pulses to the pieces of raw material (5). In a cross-sectional view, the conveyor belt (1) has a V or U shape with two lateral flanks (14) in the section in which the sensory analysis is carried out, said flanks forming an angle (α) relative to the horizontal (15). The pieces of raw material (5) are laterally fixed between the two flanks (14) of the conveyor belt (1). By laterally fixing the pieces of raw material (5), a high precision is achieved, and sorting errors are largely omitted. The invention also relates to a corresponding device for carrying out the method.

Description

The invention relates to a method for sorting pieces of raw material, which are subjected to a sensory, preferably spectroscopic analysis of the composition, wherein the pieces of raw material are applied to a conveyor belt and moved through this in the conveying direction, a sensory analysis of the composition of the pieces of raw material is performed and the raw material pieces are sorted into individual target fractions as a function of the determined composition by being acted upon with gas pressure pulses, preferably air pressure pulses, or mechanical pulses transversely to the conveying direction of the conveyor belt. Correspondingly, the invention also relates to a device with which the method according to the invention can be carried out.

In times of scarce and more expensive resources, the recycling of secondary raw materials, for example in the form of scrap recycling, is of considerable economic importance. This is all the more so since large parts of the raw materials used come from third countries, which can not always guarantee security of supply. Finally, the recycling of secondary raw materials is also environmentally desirable.

The secondary raw materials are usually present as fractions, which consist of a large number of individual pieces of raw materials. In the case of new rotations from processing, the individual fractions usually originate from individual disposal points (places of origin), old scrap is made from raw materials different and undefined origin together. Examples include non-ferrous metal fractions from large shredder plants or metallic waste from waste incineration. Even the elimination of Neuschrotten from a certain point of disposal may in turn have different chemical compositions in the individual pieces. Overall, therefore, the individual fractions are presorted at best in terms of belonging to a base material, but often differ significantly in their chemical composition in the alloy spectrum. For example, meta lisch rotte composed of individual parts of different alloy contents together. A sorting of metal scrap mixtures is currently often still in the way that the scrap is exported to developing and emerging countries and sorted there by hand. However, the working conditions prevailing here are mostly unacceptable and, in addition, the transport of the scraps causes high additional costs. From an ecological point of view too, the transport of metaphoric rots over long distances is doubtful. Finally, by exporting the scrap valuable raw materials are withdrawn from circulation inland.

For the production of high-performance materials, the exact chemical composition of the target melt is of utmost importance. Here, the economic and ecological endeavor, the highest possible proportion of secondary raw materials to the Gattierung, d. H. the Schmelzofenbesatz to obtain. A mere presorting for individual scrap groups is hardly sufficient, even for simpler commodity materials. For the production of high performance alloys (HPA), which have particular physical properties in terms of strength, wear and corrosion behavior, heat resistance, conductivity, etc., the use of secondary raw materials becomes increasingly difficult or precipitates per se. In addition, hitherto disturbing alloying elements are still slagged to a large extent in necessary metallurgical treatment of the target melt and thus ultimately destroyed, which in the long term is neither economically nor ecologically acceptable.

As the requirements for materials adjusted by macro and micro alloys continue to increase, new alloys are constantly being added always produced finer coordinated alloying shares. However, these alloying constituents may interfere with subsequent recycling as scrap, particularly if the recycling takes place by smelting in induction furnaces which do not permit metallurgical work-up. For example, micro-alloying elements, which make up high-strength steel sheet materials, interfere with the indentation of spherical graphite in ferritic basic structure during high-performance iron casting.

Therefore, only portions of presorted secondary raw materials from the procurement market for the target melt are usually used. These are then blended with primary raw materials of known composition so that maximum permitted alloy contents are adjusted and, in particular, interfering alloy constituents are pressed below a specified specification limit. This is especially the case with the melting of aluminum. Aluminum is undignified and largely eludes the metallurgical treatment option. At the same time, however, e.g. when used in the automotive industry, the aluminum used for reasons of carbon footprint have the highest possible proportion of secondary aluminum. In the interests of a functioning, ecologically sound circular economy, increasing the proportion of secondary raw materials would therefore be desirable.

In order to achieve this goal, a sorting of the pieces of raw materials according to their chemical composition is indispensable. Spectroscopic methods, in particular LIBS (laser-induced breakdown spectroscopy), are suitable for this purpose. This surface-sensitive method is in principle very suitable for determining the composition of a piece of raw material within very short times, but requires at the time of measurement a sufficiently deep penetration into the surface of the material and this a quiet position of the piece of raw material on the conveyor unit. In addition, many pieces of raw materials are provided with a surface coating. For example, a large part of the recycled steel scrap is galvanized. A LIBS measurement on the untreated piece of raw material would Therefore, lead to a falsified result, which is why the actual determination of the composition often has to be preceded by an ablation step in which takes place at least in the areas of the piece of raw material, in which finally the determination of the composition is carried out first a detachment of the surface coating. The ablation, that is, the detachment of the surface coating by evaporation, is performed using a laser, either with the same laser used to determine the composition, or with a separate laser. The ablated areas are very small. They move in the range of a few tenths of a square millimeter. Therefore, in order to coordinate a separate ablation procedure and the subsequent LIBS measurement with two lasers or for ablation and subsequent integrated LIBS measurement in the ablated area with a laser, the movement of the scrap piece relative to the conveyor must be virtually zero. It is of great importance here that the piece of raw material between the ablation step and the measuring step does not change its position relative to the conveying unit, since otherwise it can not be ensured that the measurement is not adversely affected by surface coverings which were not previously ablated.

In order to ensure a sufficiently high throughput, it makes sense to run the pieces of raw material on a conveyor belt on which a first sensory analysis of the composition and depending on the determined result, a sorting of the raw material pieces to individual target fractions in a single pass. For the actual sorting step, especially applied from the side of the conveyor belt on the raw material pieces gas pressure pulses, usually air pressure pulses that ensure by a targeted gas shock that the piece of material shot down from the conveyor belt and collected by a catcher for the respective target fraction. Such methods are basically known from air pulse devices mounted largely perpendicular to the conveying direction, but so far in practice only two different target fractions can be trapped in this way, even with three target fractions there is a disproportionate number of incorrect sorting. It is therefore the task of developing a method of the type mentioned in such a way that the raw material pieces can be sorted in one pass significantly more different target fractions, theoretically in almost unlimited numbers, without causing a disproportionate number of faulty sorting.

This object is achieved by a method for sorting pieces of raw materials, which are subjected to a sensory, preferably spectroscopic analysis of the composition, with the following steps: - Applying the raw material pieces on a conveyor belt moving in the conveying direction

- sensory analysis of the composition of the pieces of raw materials

- Assortment of the raw material pieces to individual target fractions depending on the determined composition of the pieces of raw material by applying the pieces of material with gas pressure pulses, preferably air pressure pulses, or mechanical pulses transverse to the conveying direction of the conveyor belt, wherein the conveyor belt in the section in which the sensory analysis is made in the Viewed cross section has a V or U-shape with two lateral edges which form an angle to the horizontal, wherein the raw material pieces are laterally fixed between the two edges of the conveyor belt.

The invention is based on the idea of restricting, on the one hand, movements of the pieces of raw material on the conveyor belt, particularly in the lateral direction as much as possible, and on the other hand fixing the pieces of raw material with respect to the sensory analysis, in particular the laser used for this purpose, in such a way that Each piece of raw material is reached (scrap piece to the laser) and so on a scanning laser system (laser to the scrap piece) can be omitted as a rule. In this way it is ensured that the sensory / spectroscopic method is not falsified, the compositions of the raw material pieces thus determined in each case correct piece of raw material and this is detected in the right place by a pulse, usually a gas pressure pulse to bring it into the right target fraction. If the piece of raw material were to move relative to the revolving conveyor during analysis of the composition and time of detection by a gas pressure or mechanical impulse, it would not be ensured that the interplay between ablation and LIBS measurement was sufficiently accurate the impulse is detected, and not that the impulse brings the piece of raw material into the correct target fraction. The size, shape and position of the piece of raw material on the one hand and momentum must in fact be coordinated so that the piece of raw material does not accidentally get into the wrong target fraction. If prior to the sensory analysis step, a detachment of surface coating or impurities z. B. takes place using a laser, is also important that between this Ablationsschritt and the measuring step, the position of the piece of raw material relative to the conveyor unit also not or at most slightly changed so that it is ensured that the measuring pulse reaches a point previously from the surface coating was released. If the measuring impulse were to strike a region of the piece of raw material which continues to carry the surface coating, this would result in a defectively determined composition.

The composition of the pieces of raw material is understood in the context of the invention to mean the chemical composition.

The lateral fixation of the pieces of raw material is to be understood that the movement of the pieces of raw material on the conveyor belt is limited as far as possible transverse to the conveying direction. However, it does not always have to be an absolute fixation, in particular it is not a permanent fixation.

As a result of the fact that the conveyor belt has a V-shaped or U-shaped view, at least in the section in which the sensory analysis is taken, in cross-section, in particular lateral or lateral movements of the pieces of raw material are effectively prevented. The Raw material has a tendency through the V or U shape to remain in the lowest point of the conveyor belt, typically in the middle of the conveyor belt. This is especially true even if the piece of raw material, for example, has a round or cylindrical shape, in other words would greatly tend to roll away laterally in a flat configuration of the conveyor belt.

Due to the V or U shape of the conveyor belt, this has two lateral flanks, which form an angle to the horizontal. Between the two flanks, the pieces of raw material are transported on the conveyor belt. The V / U shape of the conveyor belt is to be understood as having a V or U shape in the area in which the pieces of raw material come to lie, so that the pieces of raw material are positioned between the two flanks; in principle, the V or U shape does not exclude that, viewed in cross section, deviating shapes are present laterally of the V or U and, for example, the overall result is a W shape. The flanks of the conveyor belt form in the section in which the sensory analysis is made, to the horizontal preferably an angle of 10 - 70 °, preferably 20 - 60 °, more preferably 30 - 50 °. These angles have proven to be suitable for laterally fixing the pieces of raw material between the flanks laterally to the extent that erroneous assignment of the measurement results or faulty sorting of the pieces of raw material to target fractions is largely ruled out.

The loading of the pieces of raw material with gas pressure pulses transversely to the conveying direction of the conveyor belt is to be understood that the gas pressure surges have at least one component transverse to the conveying direction, but not necessarily have to run in the horizontal direction. In particular, when the flank of the conveyor belt over which the gas pressure pulse is exerted forms an angle to the horizontal, the gas pressure pulse typically runs along the surface of the flank of the conveyor belt, ie at an angle to the horizontal which corresponds at least approximately to the angle of the flank of the conveyor belt. Alternatively to the application of gas pressure pulses, the use of mechanical pulses is also conceivable. In this case, the pieces of raw material are pushed out of the conveyor belt, as it were, by mechanical means. Incidentally, for the application of mechanical pulses to the raw material pieces, the statements made regarding gas pressure pulses apply correspondingly.

According to an advantageous embodiment, at least one flank of the conveyor belt is flattened in the section in which the raw material pieces are subjected to gas pressure pulses / mechanical pulses. This occurs at least on the side of the conveyor belt which faces the target fractions. In principle, however, a flattening of both flanks is also conceivable, in particular if, for example, pulses are applied from both sides of the conveyor belt to the pieces of raw material in order to introduce them into target fractions on different sides of the conveyor belt. The flattening of the conveyor belt has the advantage that the raw material piece can be moved down here more easily from the conveyor belt by means of a gas pressure or mechanical impulse and introduced into a target fraction.

In this context, it is not necessary to make a complete flattening of the target fraction facing flank, but the flank should in the just-mentioned area to the horizontal angle of max. 20 °, preferably max. 10 ° in order to avoid a "uphill mining" of the piece of raw material and to ensure easy introduction into the target fraction.

Expediently, the conveyor belt can also be completely flattened in certain areas, in other words be planar, in particular where neither a determination of the composition, an ablation or a sorting into target fractions takes place. Especially the returning conveyor belt can be flat / plan.

The conveyor belt used in the invention must be such that a certain deformability is given, it can take particular V-shaped or U-shape in some areas. It typically has a thickness of 3 to 10 mm, preferably 5 to 6 mm. Suitable for the production of the conveyor belt are in particular polyester fabric, polyamide fabric or polyester / polyamide blend fabrics. As polyamide and aromatic polyamides (aramids) can be used.

The adjustment of the angle of the conveyor belt to the horizontal is preferably carried out by arranged at appropriate angles baffles or rollers, over which the conveyor belt is guided. The conveyor belt is thus in each case a certain angle impressed at the corresponding points, which form the flanks of the conveyor belt to the horizontal. In order not to cause excessive loads on the conveyor belt, the setting of the angle is preferably not abrupt, but steadily or stepwise within a longitudinal section of the conveyor belt.

It makes sense in the section in which the raw material pieces are subjected to gas pressure or mechanical pulses, arranged laterally of the conveyor belt several receptacles for different target fractions. The collecting container can be positioned directly to the side of the conveyor belt or with a certain distance, in the latter case, means should be provided for collecting the individual pieces of raw material. From these, the pieces of raw material then pass, for example, by simply sliding into the respective collecting container. The collecting container or the means for collecting the pieces of raw material should each have a lateral boundary to ensure a clear separation of adjacent collecting containers / collecting means and to avoid mixing of the pieces of raw material. It makes sense in this context, the provision of a residual fraction, in which such raw material pieces are sorted, for which no further meaningful use is possible or which allow no analysis of the composition. The residual fraction can also be arranged at the end of the conveyor belt, i. All pieces of raw material that were not previously moved by an impulse from the conveyor belt, arrive at the end automatically in the residual fraction.

The individual fractions can be collected in the collecting containers or withdrawn continuously by conveyor belts. The gas pressure pulses, preferably air pressure pulses, are preferably applied by means of nozzles which generate a gas pressure between 4 and 15 bar, preferably 6 to 10 bar. The gas pressure depends on the nature of the pieces of raw material in terms of shape and (specific) weight. The nozzles can be integrated, for example, in an air strip. Especially for relatively small pieces of raw material, so-called Bulletvalves (eg from the company MAC) are available; These are very small valves with a high clock frequency. For larger parts, however, larger nozzles / valves are advantageous, but make a higher gas / air consumption and a higher compressor performance necessary. Valves that are integrated in an air strip often require control air for opening / closing the valve (the nozzle) and also sorting air for discharging the piece of raw material by means of a targeted air blast. It is also possible to combine different nozzles with one another, for example small nozzles for discharging small pieces of raw material and larger nozzles for applying larger quantities of gas to larger pieces of raw material.

Preferably, the analysis of the composition of the raw material pieces and the assignment to individual target fractions is automated. The system thus recognizes due to the sensory, preferably spectroscopic analysis of the composition of a particular piece of raw material, in which target fraction the respective piece of raw material is to be sorted. The important parameters in this context, for example minimum or maximum content of different elements, are entered into the system in advance. Depending on which target fraction a particular piece of raw material then has to be assigned, then the gas pressure or mechanical impulses are exercised accordingly. For this purpose, the system preferably has a device for data processing (control unit) which automatically calculates which nozzles for generating the gas pressure pulses have to be opened for the correct sorting to individual target fractions over a period of time. In addition to the position and the composition of the respective piece of raw material, the shape and possibly the mass can be taken into account. For discharging a particularly large piece of raw material, it may in fact be necessary for a plurality of nozzles to possibly be used at elevated pressure. The sensory analysis of the composition of the pieces of raw material is preferably a spectroscopic method. In this case, the analysis can also be carried out in the combination of different sensory and / or spectroscopic methods which are coordinated with respect to the task.

The described method is preferably carried out in combination with laser spectroscopy, in particular laser-induced plasma spectroscopy (LIBS). Here, a very short, high-energy laser pulse is focused on the surface to be examined. The local strong heating of the material taking place there leads to the formation of a light-emitting plasma, the emission being characteristic of the respective material. This method is particularly suitable for analyzing the composition of secondary raw material pieces. At the same time, the exact feeding, separating and recording of the individual pieces of raw material when using LIBS are particularly important because the individual pieces of raw material must be introduced into the beam path of the laser in order to obtain a reliable statement about the composition.

To capture the individual pieces of raw material, a scan of the laser can be made. The laser beam tracks the piece of raw material during the conveying process and scans the light-optically defined areas of the piece of raw material to be analyzed. In order to achieve a sufficiently high measurement accuracy and also to be able to determine small amounts of alloy material <500 ppm or to limit the error to this order, however, the deflection of the laser beam from the main direction must not become too large and should not exceed 250 mm, preferably not more than 150 mm. For even greater distractions there is a risk that the emitted light scatters too much and therefore incorrect measurements occur.

In addition, since the measurement result in the sensory analysis by surface coatings, enrichment or depletion of alloying elements on the surface, contamination on the surface, adhering oil layers, etc., can be falsified, it can make sense before the actual analysis of the composition by a laser cleaning pulses for ablation on the pieces of raw material act. With the help of the cleaning pulses coatings and impurities of the surface can be removed, so that subsequently a genuine analysis of the composition is possible.

In order to increase the informative value of the analysis carried out, it is also possible to analyze several sites per composition of a piece of raw material, d. H. It must be done in several places, first an effect of cleaning pulses and then an effect of analysis pulses to determine the particular composition can. The results are statistically evaluated, then sorting is performed depending on the statistically determined composition.

In order to determine the locations where a sensory analysis of the composition is possible, a determination of the position of the pieces of raw material as well as a determination of spatial information regarding the pieces of raw material can be carried out. In particular, the partial or complete determination of the shape of the pieces of raw material is understood as the determination of spatial information. This serves to prepare the analysis, in particular with regard to the determination of suitable measuring points. The position is the position of the piece of raw material on the conveyor belt.

The shape, the position and / or the topography of the individual pieces of raw material can be determined with the aid of a laser-cut camera / light-section sensor preceding the actual sensory analysis. If only the information about a contour line of the piece of raw material is required in order to focus the laser for the LIBS measurement, this can also be obtained by an upstream laser triangulation. The extraction of spatial information on the pieces of raw material is also possible via a (pulsed) laser, which determines parallel to the transport direction a contour line of each piece of raw material over the light transit time. This serves to prepare the subsequent analysis process in the case of pieces of raw materials which, in themselves or from piece to piece, have a considerable height difference light-optical method can focus sufficiently precisely for the actual measurement. The spatial information obtained is used to determine the places where compositional analysis takes place in the subsequent step. By determining the contour line, the cycle time of the measuring processes is increased and the measuring accuracy is increased. In addition, the influence of any relative movements of the pieces of raw material relative to the conveyor belt is largely eliminated by measurement.

The determination of the position of the pieces of raw material is also possible with the help of a 3D scanning step, which can also serve to gain spatial information on the pieces of raw material. It is thus possible to detect the shape of the pieces of raw material. The spatial information about the pieces of raw material, in particular the shape, is automatically evaluated at which positions a sensory / spectroscopic analysis is easily possible. In this way, the analysis can be significantly accelerated, since the number of unsuccessful analysis steps is minimized. 3D scanning technologies, which are generally carried out with the aid of a laser, are well known to the person skilled in the art and are used in a variety of ways, for example for determining the shape of dental arches, in rapid prototyping, etc. The review article by WR Scott, by way of example only, is by way of example , G. Roth, ACM Computing Surveys, Vol. 35, 2003, pp. 64-96, "View Planning for Automated Three-Dimensional Object Reconstruction and Inspection".

Instead of capturing position and shape with the help of 3D scanning, other possibilities are conceivable. For example, the position of the piece of raw material in the case of metals can be determined by electromagnetic induction. For this purpose, coils may be provided, for example, below the conveyor belt, which together with a capacitor form a resonant circuit, so that the position of a metallic piece of raw material is detected electronically. Devices in which the presence of a metallic object can be detected by means of electromagnetic induction are known in principle to the person skilled in the art. The pieces of raw material should preferably be individually and spaced apart on the conveyor belt, so that misallocations are avoided. Even with the discharge by means of gas pressure or mechanical pulses, it makes sense if the pieces of raw material are individually on the conveyor belt, so that they do not interfere with each other and the wrong target fraction are supplied. Appropriate separation techniques are known in principle from the prior art, for example by means of a vibrating conveyor.

The pieces of raw materials are preferably secondary raw material pieces, ie. H. Parts to be recycled. However, this does not exclude that, at least in part, primary raw material pieces can also be used to produce certain compositions. As a rule, these are meltable raw materials; ideally, these only have to be melted down in order to obtain a target melt of the desired composition, so that an admixture of other substances or a removal of substances from the melt is no longer or only to a very small extent necessary to produce a new material.

The inventive method can be used for different types of pieces of raw materials, namely metallic, organic and inorganic raw material pieces as well as combinations thereof. Of particular importance is the sorting of metallic raw material pieces, ferrous metals as well as non-ferrous metals. One purpose is about the sorting of different steel scrap, just as well, however, the method for copper, brass, aluminum, zinc, titanium or other metals can be used. Typical alloy systems are, for example, manganese, chromium and nickel in iron or magnesium and silicon in aluminum.

The size of the pieces of raw material can vary over a wide range. It essentially depends on the design of the system. This depends on the purpose. As a lower limit, the pieces of raw material must have a size that allows a sensory analysis; this is also dependent on the conveying speed. At conveying speeds <1 m / s, it is also possible to analyze pieces of raw material with a length of less than 1 cm. Whether this can be done economically must be examined on a case-by-case basis. With regard to the upper limit, the pieces of raw material should only be so large as to allow discharge by means of gas pressure pulses or mechanical devices into a single target fraction. The length of the pieces of raw material should therefore, if possible, not exceed 1 m; lengths of up to approx. 600 mm are preferred. The length of the piece of raw material is understood in this context as the largest dimension of the piece of raw material. Depending on the size of the pieces of raw material, it may be useful to crush them before analysis of the composition in order to make them easier to handle.

Secondary raw materials also distinguish between new scraps and old scraps. Scrap are those that have been used under certain circumstances for long periods of time, such as car bodies to be reworked or the corresponding scissors or shredder scrap. Neuschrotte are those that arise in the manufacture of components, such as the remains of a sheet from which a certain shape was punched out. Also conceivable is the use in the recycling of plastic parts or glass. The method according to the invention can be used within the scope of a scrap processing, as described in DE 10 2012 015 812 A1, or within the scope of an assorting method (DE 10 2012 024 816 A1), in which target fractions of recyclable raw materials with certain desired compositions are produced. In this regard, reference is made to the aforementioned documents.

It is helpful if the pieces of raw material are at least roughly presorted with regard to their basic composition, for example with regard to the base material or the layer system, or else with regard to their size. With a known basic composition, it can be decided whether a treatment of the pieces of raw material with mechanical processes or with one or more liquids for cleaning the surface and / or for detachment of surface coatings, ie blasting or pickling is necessary before the actual process according to the invention is carried out. Here, different approaches may be useful, depending on whether it is z. B. galvanized, enamelled or provided with a Kunststoffbeschichtung scrap or plastic remnants. For example, as a paint remover for removal of organic Coatings organic solvents such as aliphatic or aromatic hydrocarbons, chlorinated hydrocarbons, alcohols, glycol ethers, dicarboxylic acid esters, acetone, etc. may be used. Methylene chloride is used most frequently. To remove a zinc layer, acids or bases can be used. Corresponding methods are known to the person skilled in the art. To further increase the efficiency, the pieces of raw material to be treated can expediently be mechanically pretreated before being brought into contact with the liquid, in particular comminuted, shredded, roughened and / or otherwise deformed in order to increase the contact surfaces to the liquid. Possibly. Drying of the pieces treated with the liquid may be carried out prior to the analysis in order to remove adhering liquid residues.

In order to ensure a high throughput, but at the same time be able to make a meaningful analysis of the composition and sorting, has for the conveyor belt, a suitable conveying speed of 0.5 to 6 m / s, preferably 1 to 5 m / s, more preferably 2 exposed to 4 m / s.

In addition to the method according to the invention, the invention also relates to a device for sorting pieces of raw materials with a conveyor belt which is suitable for moving the pieces of raw material in a conveying direction, a sensory, preferably spectroscopic measuring method for analyzing the composition of the pieces of raw material and gas pressure nozzles for pressurizing the pieces of raw material with gas pressure or mechanical devices for mechanically loading the pieces of raw material transversely to the conveying direction of the conveyor belt, wherein the conveyor belt in the section in which the spectrometer determines the composition of the pieces of raw material, a V-shaped or U-shaped with two lateral edges (14) having an angle (a) to form the horizontal (15). Preferably, the conveyor belt is flattened on at least one flank in the section in which the pieces of raw material with gas pressure or mechanical pulses can be acted upon.

All embodiments that are made in the context of the invention to the method apply in the same way for the devices. this applies in particular for all features described in connection with the method and vice versa.

The invention will be explained in more detail by way of example with reference to the attached figures. Show it:

A device according to the invention in side view;

2 shows a cross section through the conveyor belt in the section in which the spectroscopic analysis is performed, and

Fig. 3 shows a cross section through the conveyor belt in the section in which the raw material pieces are subjected to gas pressure pulses. FIG. 1 shows a conveyor belt 1 on which a plurality of pieces of raw material 5 are moved in the conveying direction 2. To simplify the illustration, the raw material pieces 5 are arranged here relatively regularly on the conveyor belt 1, but in practice this is usually not the case. The conveyor belt 1 is driven by rollers 4 and is shown here flat for illustrative reasons, in fact, it has, at least in sections, a V-shape, as shown in Figures 2 and 3. At the end of the conveyor belt 1 is a waste container 8, in which such pieces of raw material 5 are collected, which are not accessible for further use or in which no analysis of the composition was possible. The analysis of the composition of the pieces of raw material 5 is carried out with the aid of a laser 3 which generates laser pulses, it being necessary to distinguish between cleaning pulses 6 and analysis pulses 7. In each case, cleaning pulses 6 and then act on a specific piece of raw material 5 Analysis pulses 7 a. The control unit ensures that the analysis pulses 7 are directed to the locations of the pieces of raw material 5 on which a material removal by cleaning pulses 6 has previously taken place. For this purpose, the control unit takes into account the position of the pieces of raw material 5, the speed of the conveyor belt 1 and the steering of the cleaning pulses 6 and the analysis pulses 7. The position and shape of the raw material pieces 5 has been previously detected by the laser cutting camera 9, so that the control unit cleaning and 6 analysis pulses 7 to the right positions.

In the rear region of the conveyor belt 1 finally gas pressure nozzles 10 are arranged, which are applied to the raw material pieces 5, which are assigned to a specific, not shown here target fraction, from the side of the conveyor belt 1 with gas pressure pulses. The control unit thus ensures that, depending on the determined composition of a particular piece of raw material 5, this is pushed by gas pressure, usually air pressure surges from the conveyor belt 1.

FIG. 2 shows a cross section through the conveyor belt 1 in the section in which the spectroscopic analysis is carried out. The conveyor belt 1 is bent in the middle in such a way that two flanks 14 result, each forming an angle α to the horizontal 15. Due to the V-shape of the conveyor belt 1, the pieces of raw material 5 are so largely limited in freedom of movement that a change in position relative to the conveyor belt 1 between the determination of the position and shape by the laser-cut camera 9, the application of cleaning pulses 6 and 7 analysis pulses the laser 3 and finally the discharge by gas pressure nozzles 10 is practically excluded.

Finally, FIG. 3 shows a cross section through the conveyor belt 1 in the section in which the raw material pieces 5 are subjected to gas pressure pulses 11. One of the two flanks 14, namely the flank 14 facing the catching device 12 with individual target fractions 13, is here flattened, ie the angle β is considerably smaller than the angle a, which the flank 14 of the conveyor belt has previously formed in FIG. By the gas pressure nozzles 10 are gas pressure pulses 1 1 targeted to the Raw material pieces 5 exercised so that they are introduced laterally from the conveyor belt 1 in a specific target fraction 13. Due to the flat position of the target fractions facing edge 14, the discharge of the raw material pieces 5 facilitates by means of compressed air significantly.

Claims

claims

1. A method for sorting pieces of raw material (5), which are subjected to a sensory, preferably spectroscopic analysis of the composition, with the following steps:

- Application of the raw material pieces (5) on a in the conveying direction (2) moving conveyor belt (1)

- sensory analysis of the composition of the pieces of raw material (5)

- Assignment of the raw material pieces (5) to individual target fractions (13) depending on the determined composition of the raw material pieces (5) by applying the pieces of raw material (5) with gas pressure pulses (11), preferably air pressure pulses, or mechanical pulses transversely to the conveying direction (2) of the Conveyor belt (1), characterized in that the conveyor belt (1) in the section in which the sensory analysis is carried out, when viewed in cross-section, has a V- or U-shape with two lateral flanks (14) which form an angle (a) form the horizontal (15), wherein the raw material pieces (5) are laterally fixed between the two edges (14) of the conveyor belt (1).

2. The method according to claim 1, characterized in that the

Flanks (14) of the conveyor belt (1) in the section where the sensory Analysis is made to the horizontal (15) an angle (a) of 10 to 70 °, preferably 20 to 60 °, more preferably 30 to 50 °.

3. The method according to claim 1 or 2, characterized in that the conveyor belt (1) in the section in which the raw material pieces (5) with gas pressure pulses (1 1) or mechanical pulses are applied, on the target fractions (13) facing flank (14) is flattened.

4. The method according to claim 3, characterized in that the target fractions (13) facing edge (14) of the conveyor belt (1) in the section in which the raw material pieces (5) with gas pressure pulses (1 1) or mechanical pulses are applied, to the horizontal (15) an angle (ß) of max. 20 °, preferably max. 10 °.

5. The method according to any one of claims 1 to 4, characterized in that the conveyor belt (1) extends partially planar.

6. The method according to any one of claims 1 to 5, characterized in that the adjustment of the angle (α, β) of the conveyor belt (1) for

Horizontal (15) arranged at corresponding angles baffles or rollers.

7. The method according to any one of claims 1 to 6, characterized in that in the section in which the raw material pieces (5) with gas pressure pulses (1 1) or mechanical pulses are applied, laterally of the conveyor belt (1) a plurality of collecting containers for different target fractions ( 13) are arranged.

8. The method according to any one of claims 1 to 7, characterized in that the gas pressure pulses (1 1) by means of gas pressure nozzles (10) are applied, which generate a pressure between 4 and 15 bar, preferably between 6 and 10 bar.

9. The method according to any one of claims 1 to 8, characterized in that the analysis of the composition of the raw material pieces (5) and the assignment to individual target fractions (13) carried out automatically.

10. The method according to claim 9, characterized by a

Control unit that automatically calculates which gas pressure nozzles (10) for generating the gas pressure pulses (1 1) over which period for correct sorting to individual target fractions (13) must be opened.

1 1. Method according to one of claims 1 to 10, characterized in that the analysis of the composition of

Raw material pieces (5) with the aid of laser-induced plasma spectroscopy (LIBS) takes place.

12. The method according to any one of claims 1 to 1 1, characterized in that before the analysis of the composition cleaning pulses (6) by a laser (3) for the removal of coatings and impurities on the surface of the pieces of raw material (5) are applied.

13. The method according to any one of claims 1 to 12, characterized in that prior to the analysis of the composition, a determination of the position and / or spatial information of the raw material pieces (5).

14. Device for sorting pieces of raw material (5) with a conveyor belt (1) which is suitable for moving the pieces of raw material (5) in a conveying direction (2), a sensory, preferably spectroscopic measuring method for analyzing the composition of the pieces of raw material (5) and gas pressure nozzles (10) for pressurizing the raw material pieces (5) with gas pressure or mechanical devices for mechanically loading the pieces of material transversely to the conveying direction (2) of the conveyor belt (1), characterized in that the conveyor belt (1) in the section in which the Spectrometer the composition of Raw material pieces (5) determined, a V or U-shape with two lateral edges (14) which form an angle (a) to the horizontal (15).

15. The apparatus according to claim 14, characterized in that the conveyor belt (1) in the section in which the raw material pieces (5) with gas pressure pulses (1 1) or mechanical pulses are acted upon, flattened on at least one edge (14).