EP3452225A1

EP3452225A1 - Crushing plant and crushing method for crushing aluminum scrap

Info

Publication number: EP3452225A1
Application number: EP17721622.3A
Authority: EP
Inventors: Thomas Brößner; Ronald Gillner; Michael Wimmer; Michael Jenal; Heiner Müller; Nils Robert Bauerschlag
Original assignee: Hydro Aluminium Rolled Products GmbH
Current assignee: Speira GmbH
Priority date: 2016-05-02
Filing date: 2017-05-02
Publication date: 2019-03-13
Anticipated expiration: 2037-05-02
Also published as: WO2017191134A1; EP3452225B1; DE102016108105A1

Abstract

The invention relates to a crushing plant (52) for crushing aluminum scrap (56), in particular UBC scrap, having a crushing device (58) for crushing aluminum scrap, which crushing device is designed as a high speed operator, wherein a pre-crushing device (54) for pre-crushing aluminum scrap is connected upstream of the the crushing device (58) and is designed as a low speed operator. The invention further relates to a crushing method for crushing aluminum scrap (56), in particular UBC scrap, wherein a quantity of aluminum scrap (56) is crushed by a pre-crushing device (54) designed as a low speed operator and wherein the pre-crushed aluminum scrap (60) is further crushed by a crushing device (58) designed as a high speed operator. The invention further relates to recycling plant comprising the crushing plant (52) and to a recycling method comprising the crushing method.

Description

Crushing and crushing process for crushing aluminum scrap

The invention relates to a crushing plant for comminution of

Aluminum scrap, in particular UBC scrap, with a comminution device for comminuting aluminum scrap, which is designed as a high-speed extruder. The invention further relates to a comminution method for comminuting aluminum scrap, in particular UBC scrap, in particular using the aforementioned comminution plant. According to the prior art, the recycling of aluminum takes place over several

Process steps. These usually include the collection of different aluminum scrap, a mechanical treatment with the subsequent metallurgical utilization. For resource-efficient recycling, mechanical treatment must produce an aluminum scrap product that meets the qualitative requirements of the metallurgical recycling process. For this purpose, different treatment steps are carried out.

The mechanical treatment of the scrap is usually done via a

Crushing, followed by various sorting steps. The sorting steps may include, for example, iron and non-ferrous metal separation via magnetic separators, air classification, eddy current separation, sensor-based sorting (for example, X-ray transmission or fluorescence, induction, LIBS, NIR, etc.). The procedural combination of the sorting steps allows the sorting out of different impurities or the sorting into different aluminum qualities. Goal of the mechanical

Processing may be to produce an aluminum concentrate that can be used directly for metallurgical recovery. In terms of process technology, comminution plants are generally produced directly (or indirectly) with mobile or stationary feed units such as wheel loaders, polyp grippers, etc.

Forklifts, cranes, etc. charged. Here, the operator has a direct influence on the mass flow rate of the crushing plant, which can lead to significant throughput fluctuations.

Despite the attempt to control shredding via process parameters,

for example, by weighing systems, fluctuating output quantities are the

Regularly observe comminution, which can reach up to twice the regular output in the short term.

The throughput fluctuations of the crushing plant also have a direct influence on the comminution or on the comminution result. For example, different mass flows in a hammer mill lead to it

different degrees of comminution, wherein the scrap is typically comminuted into smaller fragments, the larger the mass or volume flow. High mass or volume flows also lead to excessive wear of the hammer mill. The fluctuating output levels of crushing and the fluctuating

Size distribution of the shredded scrap fragments also lead to problems in the downstream sorting. For example, sudden peaks in throughput often lead to disruptions in the sorting system. Furthermore, a single grain sorting at too high degrees of comminution, i. if the size of the crushed pieces is too small

Scrap fragments (so-called fine grain) and a correspondingly large number of

Fragments ineffective.

This problem occurs especially when recycling UBC scrap. Under UBC (used beverage can) scrap is understood (aluminum) beverage can scrap, which accounts for a large proportion of the total emerging aluminum scrap from the area The importance of packaging Therefore, there is a great need for an effective and robust recycling process for UBC scrap.

UBC scrap typically has a variety of contaminants, for example metallic impurities of cast aluminum or even out

Non-aluminum alloys such as copper or iron alloys. Furthermore, UBC scrap typically contains non-metallic contaminants such as plastic films or mineral contaminants. These various impurities must be sorted out in the sorting process before metallurgical reuse. Furthermore, the cans are painted as a rule, so that before melting the can scraps and a stripping takes place.

UBC scrap is typically compressed into packages for shipping and storage. The degree of compaction of the packages can be very different and vary, for example, between 200 and 1200 kg / m ³ . This leads to large throughput fluctuations in the shredding of the scrap packets and thus to the problems described above.

Against this background, the object of the present invention is to provide a comminution unit and a comminution method, with which the problems described above, in particular in the comminution of UBC scrap, are at least partially reduced.

According to a first aspect of the present disclosure, this object is achieved in a crushing plant for crushing aluminum scrap, in particular UBC scrap, with a comminution device for comminution of

Aluminum scrap, which is designed as a high-speed rotor, according to the invention at least partially solved in that the crushing device a

Pre-crushing device is preceded for pre-shredding aluminum scrap, which is designed as a slow-speed. According to the first aspect of the present disclosure, the above-mentioned object is further achieved according to the invention at least in part

Crushing process for crushing aluminum scrap, in particular UBC scrap, in particular using the previously described

Crushing plant in which a lot of aluminum scrap with a

Slow speed trained pre-crushing device is pre-crushed and in which the pre-shredded aluminum scrap with a high-speed

trained crushing device is further crushed. It has been recognized that a robust and uniform comminution of UBC scrap can be achieved by a two-step comminution, with one for the first comminution step and one for the second

Crushing step a high-speed extruder is used. The slow runner pre-shreds the UBC scrap, in particular breaking up the packages in which UBC scrap is normally provided. By breaking up the packages, in particular, the highly compacted packages with densities of, for example, 800 kg / m ³ or more

loosened, so that the density of the scrap is made uniform. The use of a slow runner ensures that the pre-crushing device

can apply sufficient torque to break even very strong compacted packages. The slow runner therefore has in particular the function of a bale breaker. In this way, a more uniform mass or volume flow is achieved, which is supplied to the subsequent crushing device. This leads to constant degrees of comminution in the comminution device, so that the scrap fragments leaving the comminution system have as much as possible

have the same size distribution. The more uniform mass or

Flow rate also allows the shredding device at the optimum Operating point, and also reduces the wear of the crushing device.

A mass flow is understood as meaning the mass of the transported fragments or of a plant added to or removed from a plant scrap fragments per time. If the crushing plant, for example, a mass flow of 10 t / h supplied, it means that the crushing plant is supplied in this mass flow in one hour 10 tons of scrap. A volumetric flow is understood to mean the volume of the scrap fragments conveyed or taken to or from a plant per unit of time. If the shredding plant, for example, a volume flow of 10 m ³ / h supplied, it means that the crushing plant is supplied at this volume flow in one hour 10 m ³ scrap.

If the bulk density of the scrap fragments is known, then the mass flow can be simply converted into the volume flow or the volume flow into the mass flow. The slow runner continues to serve the protection of the fast runner. For example, in highly compacted scrap packages, massive metal parts, such as an anvil or the like, which are strong in speed can be hidden

would damage. Although such metal parts lead to a slow motion in a slow-moving, but typically not to damage, so that the relevant metal part can be removed from the collection of slow-moving and operation can be resumed after a short break.

The comminuting device for comminuting aluminum scrap is designed as a high-speed machine. Under a high-speed runner becomes a

Crushing device with an operating shaft rotating with

Grinding tools understood, which is adapted to the shaft with the shredding tools in operation at a speed of more than 100 rpm. (Revolutions per minute), preferably more than 250 rpm. rotates.

The pre-crushing device for pre-shredding aluminum scrap is designed as a slow-speed. Under a slow runner is a

Crushing device with an operating shaft rotating with

Understood shredding tools, which is adapted to the fact that the shaft with the crushing tools in operation at a speed of 100 U / min., In particular, at most 60 U / min. Preferably, the shaft of the slow runner is reversible, i. that the shaft can be selectively controlled for rotation in both directions of rotation.

The pre-crushing device is connected upstream of the crushing device. This means that the scrap supplied to the crushing plant is first pre-shredded in the pre-crushing device, before it in the

Crushing device is further crushed. For example, the

Crushing system have a transport system to those of the

Vorzerkleinerungsvorrichtung pre-shredded scrap to

To transport crushing device.

The above object is further achieved according to the invention, at least partially, by a recycling plant for the treatment of aluminum scrap, in particular UBC scrap, which comprises the comminution plant described above. Accordingly, the abovementioned object according to the invention is also at least partially solved by a recycling process for the preparation of

Aluminum scrap, in particular UBC scrap, preferably using the recycling plant described above, in which a lot of scrap is comminuted by the crushing method described above and in which the

shredded scrap is further processed in particular sorted. The sorting is preferably a sensor-based sorting, in particular a LIBS-based sorting. Additionally or alternatively, for example, an X-ray transmission-based, an X-ray fluorescence-based, an induction-based and / or an NIR-based sorting come into consideration.

LIBS stands for Laser-Induced Plasma Spectroscopy (Laser Induced Breakdown Spectroscopy). NIR stands for near-infrared spectroscopy.

The crushing plant is therefore preferably in a recycling plant for

Reprocessing of UBC scrap embedded. Such a recycling plant comprises in addition to the crushing vorzugswese a crushing plant downstream sorting system for sorting the crushed scrap, in particular for

Sorting out impurities. Furthermore, one of the sorting plant downstream Entlackungsanlage can be provided for stripping the scrap fragments and a the Entlackungsanlage downstream melting furnace for melting the entlackten scrap fragments.

If the crushing plant downstream of a sorting plant for sorting the crushed scrap, it is preferably for a sensor-based sorting, in particular LIBS-based sorting, set up. In addition or as an alternative, the sorting system can, for example, also be set up for X-ray transmission-based, X-ray fluorescence-based, induction-based and / or NIR-based sorting. In the following, various embodiments of the crushing plant, the recycling plant, the comminution process and the recycling process will be described, the individual embodiments being described in each case both for the

Crushing plant and the recycling plant, as well as for the

Shredding process and the recycling process are applicable and can be combined with each other. In a first embodiment, the crushing device is to

arranged to crush aluminum scrap substantially hitting and / or shearing, in particular as Hauptbeanspruchungsart. Beating comminution is understood to mean that a scrap fragment experiences stress from a fast moving surface. Under a shearing crushing is understood that a scrap fragment a

Stress from two oppositely moving lines experiences. Under the

Hauptbeanspruchart the stress (such as shearing, hitting, outgoing, etc.) understood by which the scrap fragments are mainly claimed in the crushing.

In a further embodiment, the crushing device is a

Single-shaft shredder, hammer mill or ring shredder.

A single-shaft shredder has fixedly mounted blades on a rotor shaft, which engage in a counter blade mounted on the housing. The comminution takes place in a single-shaft shredder essentially shearing and cutting or

shearing and tearing. Single-shaft shredders are particularly good for the

Shredding thin-walled can scraps suitable, but can be easily damaged by massive foreign waste.

A hammer mill has hammers movably mounted on a rotor shaft. A ring shredder resembles a hammer mill, with movably mounted rings or stars instead of the hammers on the rotor shaft. The

Crushing takes place in a hammer mill and a ring shredder in

Essentially hitting and shearing. A hammer mill or a ring shredder are also well suited for shredding tin cans. In particular, the beating and shearing stress of the scrap leads to a loosening of the compressed UBC scrap, whereby a homogenization of the scrap can be achieved. In addition, hammer mills and ring shredders are less sensitive against massive foreign waste up to a certain size. Therefore, a hammer mill or a ring shredder is preferred for the crushing device, since they are not damaged by massive foreign scrap passing through the pre-crushing.

The homogenization of the mass or volume flow achieved by the pre-comminution device is particularly advantageous in the case of a hammer mill

Shredding device advantageous because the degree of comminution of the hammer mill depends heavily on the throughput. If the crushing space is underfilled in the hammer mill, the crushing capacity is low. If the degree of filling is too high, the crushing of the scrap is too great, so that a large amount of fine grain is produced, which is disadvantageous for subsequent sorting. With optimum filling of the crushing space is filled to the extent that sufficient friction of the scrap fragments occurs among themselves to achieve the desired particle size distribution.

In a further embodiment, the pre-shredding device is adapted to shred aluminum scrap substantially tearing and / or shearing, preferably non-cutting. By a ripping or shearing crushing the UBC scrap packages can be broken particularly effectively, so that in particular the high density of highly compacted packages is reduced.

In a further embodiment, the pre-shredding device is a

Multi-shaft shredder, in particular a two- or three-shaft shredder.

Such shredders are also referred to as ripper. Multi-shaft shredders have multiple shafts with ripping tools, at least two of which run in opposite directions.

The breaker preferably has several, in particular at least three

driven waves, on each of which one or more preferably

Ripper discs are arranged. The rupture discs can, for example, as Star discs or hook discs may be formed. The shafts are preferably driven to rotate in operation at speeds in the range of 1 to 30, preferably 5 to 20 revolutions per minute. With these speeds, high torques can be achieved in order to be able to break up even highly compacted scrap packages. The speeds of rotation of the shafts are preferably different. For example, two waves with speeds between 10 and 30

Revolutions per minute or three waves with speeds of 5, 10 and 20

Be provided revolutions per minute. In a further embodiment, the pre-crushing device

Aluminum scrap delivered in packages, especially in different

Kompaktierungsgraden. In particular, the package-wise feeding leads

Prior art crushers have become uneven

Mass flow, so that the crushing plant described herein and the crushing process described herein are particularly advantageous in this type of scrap supply.

In a further embodiment, the pre-shredding device is adapted to comminute the supplied aluminum scrap so that the pre-crushed aluminum scrap has a particle size distribution in which d95 <1000 mm, in particular d95 <500 mm, and more preferably d5> 50 mm. The comminution device is preferably configured to further comminute the pre-shredded scrap aluminum in such a way that the comminuted material is shredded

Aluminum scrap has a particle size distribution in which d95 <200 mm, in particular d95 <100 mm, and more preferably d5> 1 mm. Such a particle size distribution is advantageous for subsequent sorting.

The particle size distribution or the values for d5, d95, etc. are determined by a

Sieve analysis according to DIN 66165-1 and 66165-2 determined with test sieves according to DIN ISO 3310-2: 2015-07 (test sieves with perforated plates) and DIN ISO 2395: 1999-01. In a further embodiment, a transport system is provided between the pre-crushing device and the crushing device, which is adapted to pre-shredded from the pre-crushing device

To transport aluminum scrap to the crushing device and supply this. In a corresponding embodiment of the

Crushing process, the pre-shredded aluminum scrap is transported by means of a transport system to the crushing device. The transport system may for example have one or more conveyor belts with which the pre-shredded scrap from the

Pre-crushing device is transported to the crushing device. With such a transport system, an automated operation of the

Crushing plant can be realized.

Preferably, the transport system is adapted to supply the aluminum scrap to the crushing device controlled. At another

Embodiment is the pre-shredded aluminum scrap of

Controlled crushing device, in particular with a predetermined volume flow or mass flow, feeds. In this way, the most uniform volume or mass flow can be achieved in the crushing device, so that it can be operated at the optimum operating point. The transport system may for example have a weighing device such as a belt scale and control the conveying speed of the scrap depending on the weight determined by the weighing device. Furthermore, it is conceivable that the conveying speed of the scrap depends on one of the

To control the comminution device detected parameters, for example, the torque of the motor of the comminution device. In a further embodiment, the transport system comprises a

Vibratory conveyor designed to control the volume or mass flow of the to equalize pre-shredded aluminum scrap from the pre-shredding device. The vibrations transmitted from the vibration conveyor to the pre-shredded scrap cause the individual scrap fragments to spread more evenly. In this way, a more uniform volume or mass flow can be achieved.

In a further embodiment, the transport system between the Vorzerkleinerungsvorrichtung and the crushing device a

Additional job site, which is positioned and adapted to a separate supply of aluminum scrap to the transport system to

enable. In this way, it is possible to continue to operate the crushing plant even with a temporary failure of Vorzerkleinerungsvorrichtung by scrap is placed downstream of the Vorzerkleinerungsvorrichtung on the transport system.

The additional application point may be, for example, a straight section of a conveyor belt, which is within reach of a Polypgreifer or a

Crane system is arranged. Furthermore, as an additional application point and a section of a conveyor belt can be provided, which is arranged below a starting point for a truck or forklift, so that of such a truck or

Forklift scrap can be applied to the conveyor belt. The

Transport system is preferably designed so robust that it is suitable for such an additional task of scrap at the additional application point. At a

Conveyor belt, for example, a steel plate belt can be used for conveying.

In a further embodiment, a chute arranged in this way is provided on the pre-shredding device so that aluminum scrap can be supplied to the pre-shredding device by being placed on the chute. In this way, even with discontinuous scrap feeding at the

Pre-grinder a continuous volume or mass flow be achieved. If the aluminum scrap, for example, with a Polypgreifer gradually added to the chute, so the jam accumulates on the chute on the collection of Vorzerkleinerungsvorrichtung. The Indian

Pre-shredding device processed volume or mass flow is then essentially only from the working speed of the

Pre-shredding device, i. the rotational speed of the slow runner determined and not from the discontinuous scrap feed through the

Polyp gripper. In a further embodiment, the crushing plant comprises a

Control device for controlling the crushing plant. The

Control device is preferably for controlling the crushing plant according to the above-described crushing method or a

Embodiment thereof set up. In particular, the control means may comprise a microprocessor and a memory connected thereto, the memory containing instructions whose execution on the microprocessor the

Carrying out the above-described crushing process or an embodiment thereof. In this way, an automated operation of the crushing plant can be achieved. The control device may in particular be adapted to the crushing plant, in particular the

Pre-grinder and a possible transport system to be controlled so that the crushing device is supplied to a uniform volume or mass flow. To a processing station for the treatment of aluminum scrap, such as the crushing device of the previously described

Shredder to be able to operate at the optimum operating point, the scrap fragments of the processing station are preferably supplied in a controlled manner. This can be accomplished in accordance with a second aspect of the present disclosure by a method of operating an aluminum scrap processing plant that provides scrap fragments in which the scrap fragments provided are conveyed as a stream of scrap fragments to a processing station for processing aluminum scrap, in which a flow rate value is determined on the stream of scrap fragments and the determined value for throughput is compared with a predetermined value for the throughput, the provision of the scrap fragments and / or the

Promotion of scrap fragments are controlled to the processing station depending on the result of the comparison.

Furthermore, according to the second aspect of the present disclosure, this can be achieved by a facility for processing aluminum scrap with a processing station for processing aluminum scrap, with a

A staging station adapted to provide scrap fragments, comprising a conveyor configured to transport and deliver scrap fragments provided by the staging station as power to and to the processing station, with a flowmeter adapted to a current carried by the conveyor of scrap fragments to measure a value for the flow rate of the stream, and with a

Control device adapted to receive one of

Throughput meter measured value for the throughput with a

to compare the predetermined value for the throughput and to control the provisioning station and / or the conveyor depending on the result of this comparison.

The processing station may in particular be a

Shredder act. By feeding scrap fragments with controlled throughput, the crushing plant can be operated at the optimum operating point to achieve a certain degree of comminution. With an overload of the shredder by a too high throughput it can ever Depending on the type of comminution plant, the scrap fragments may be crushed too much or too weakly.

The processing station can also be a sorting plant, for example the sorting plant of the recycling plant according to the first aspect of the present disclosure. By supplying scrap fragments with controlled throughput, the sorting system can be operated at the optimum operating point in order to reliably remove the individual scrap fragments at the highest possible level

Sort throughput. If the sorting system is overloaded due to excessive throughput, the sorting quality decreases, making it undesirable

Impurities in the emerging from the sorting plant scrap fragments stream can come.

The processing station may also be a smelting plant. By supplying scrap fragments with controlled throughput, the

Melting plant operated at the optimum operating point. An overloading of the smelting plant if the throughput is too high can cause the temperature in the smelting plant to drop too much or cause an uneven melt. The conveyor preferably comprises one or more conveyor belts.

The method of operating an aluminum scrap processing plant and the aluminum scrap processing plant according to the second aspect of the present disclosure each make independent and independent ones

teachings according to the invention.

Moreover, the second aspect of the present disclosure may be advantageously combined with the crushing method and the crushing apparatus according to the first aspect of the present disclosure. In particular, the plant for processing aluminum scrap according to the second aspect of the present disclosure may be the crushing plant according to the invention First aspect of the present disclosure, wherein the

Crushing device, a processing station for the preparation of

Aluminum scrap and the Vorzerkleinerungsvorrichtung represents a staging station. Furthermore, the preferably provided transport system of the crushing plant is the conveyor.

In a corresponding embodiment of the crushing are accordingly a conveyor, especially in the form of the preferably provided transport system, for the transport of scrap fragments of

Pre-shredding device for crushing device, a

Throughput measuring device for measuring a value for the throughput of transported by the conveyor stream of scrap fragments and a

Control device is provided which is adapted to compare the measured value with a predetermined value for the throughput and the

Pre-crushing device and / or the conveyor depending on

To control the result of the comparison. In a corresponding embodiment of the crushing process, the aluminum scrap pre-shredded by the pre-crushing device becomes the stream of scrap fragments

A crusher is conveyed, a flow rate value is determined on the stream of scrap fragments, the determined value is compared with a predetermined throughput value, and the pre-shredding device and / or the conveyance of scrap fragments to the crusher are controlled depending on the result of the comparison. Hereinafter, still further embodiments of the method and the installation according to the second aspect of the present disclosure and the

Crushing plant and the crushing process according to the first aspect of the present disclosure, wherein the individual embodiments of the method and the plant according to the second aspect and the

Crushing plant and the crushing process according to the first aspect apply equally and can be combined both with each other and with the embodiments described above.

In one embodiment, the scrap fragments are provided by a previous processing station for processing aluminum scrap. In a corresponding embodiment, the providing station is a preceding processing station for processing aluminum scrap. In this case, via the control by means of the throughput measuring device, a supply of scrap fragments to the processing station in a predetermined

Throughput range can be ensured if the previous

Processing station that provides scrap fragments with uneven or inappropriate throughput.

For buffering large throughput fluctuations of the previous one

Processing station is preferably a buffer memory, such as a buffer, between the processing station and the previous processing station. a silo, arranged. In this case, for example, the buffer memory of the buffer memory may be controlled depending on the result of the comparison to reach a supply to the processing station in a predetermined flow rate range.

In another embodiment, the flow rate value is a mass flow rate, volume flow rate, unit rate rate, or area rate value. To detect a value for the mass flow, for example, a belt weigher may be provided, which may be integrated in particular in the conveyor. To record a value for the volume flow, a

Lasertriangulationseinrichtung be provided. In laser triangulation, in particular a laser beam on the conveyor, in particular on a

Conveyor belt, directed and the position of the laser spot by means of several cameras are determined (by triangulation). In this way, the filling level of the scrap fragments on the conveyor, such as the conveyor belt, based on the vertical position of the laser spot and thus derived a value for the volume flow. To detect a value for the piece rate (ie the number of scrap fragments per unit of time) are preferably one

Separation device provided which separates the scrap fragments, and a detection device, such as a camera, a light barrier or a laser or X-ray-based detection unit that detects the scattered scrap fragments, so that the number of scrap fragments per unit time can be determined. For detecting a value for the area rate (i.e.

Scrap fragments occupied area of a conveyor belt in percent)

For example, a camera arranged above a conveyor belt may be provided, which captures image data from the conveyor belt, from which the occupied area on the conveyor belt can be determined.

In a further embodiment, the control means is arranged to compare the measured value for the throughput with a lower and an upper limit value and the providing station and / or the

To control delivery so dependent on the comparison result that the flow rate is increased by a predetermined value, if the measured value for the flow rate for a predetermined period of time is below the lower limit, and that the flow rate is reduced by a predetermined value, if the measured value for the flow rate for a given period of time is above the upper limit. The upper limit is greater than the lower limit. The lower and upper limit value is used to control to a permissible limit

Throughput range. Due to the predetermined period of time, it is also achieved that in the case of very short-term fluctuations in the throughput, there is no immediate readjustment, but only when the throughput fluctuation lasts for a certain period of time. In this way it is taken into account that certain variations in the throughput of the scrap fragments can not be avoided, so that an excessive and unnecessary regulation is avoided. In a further embodiment, the control device is configured to allow a further reduction or increase in the throughput after a reduction or increase in the throughput only after a predetermined period of time. In this way it is considered that there is a latency between the readjustment of the staging station or the conveyor and the measurable reduction or increase of the throughput. An overregulation is avoided in this way. In particular, it is avoided in this way that the throughput is increased too much, which can lead to an overload of the processing station.

In another embodiment, the controller is configured to compare the measured value for the flow rate with a first upper limit value and a second, higher upper limit value, and the

Deployment station and / or the conveyor so dependent on the result of the comparisons to control that the throughput is reduced by a first predetermined value, when the measured value for the flow rate for a predetermined period of time is above the first upper limit, and that the throughput by one second predetermined value is reduced as soon as the measured value for the flow rate is above the second upper limit. In this way, a combined control is achieved. On the one hand, with a sustained moderate deviation, i. If the first upper limit is exceeded for a certain period of time, a moderate control is performed so that too much readjustment is avoided. On the other hand, with a large deviation, i. when the second upper limit is exceeded, an immediate, preferably large, reduction in throughput is achieved to avoid overloading the processing station.

Further advantages and features of the present invention will become apparent from the following description of embodiments, reference being made to the accompanying drawings. In the drawing show

1 shows several packages of UBC scrap with a low degree of compaction, FIG. 2 shows several packages of UBC scrap with a high degree of compaction, FIG.

3 is a diagram of a recycling plant or a

4 shows the comminuting plant of the recycling plant from FIG. 3, FIG.

5 shows an exemplary embodiment of the comminution plant according to the invention and the comminution method according to the invention, FIG. 6 shows a diagram of an embodiment of the invention

Recycling plant according to the invention and the recycling process according to the invention and

7 shows an embodiment of the method and the installation according to the second aspect of the present disclosure.

The crushing plant described here or the recycling plant comprising it are provided in particular for the comminution or processing of UBC scrap. UBC scrap is scrap metal from used aluminum beverage cans. For the production of aluminum cans in practice, only a few different aluminum alloys are used, namely from the AA5xxx series (AA: Aluminum Association), especially AA5184, and from the AA3xxx series, especially AA3104, so that scrap aluminum drink cans in principle good for Recycling is suitable. However, UBC scrap available on the scrap market has, in addition to the actual aluminum can scrap, various types of impurities that must be removed before metallurgical recycling of the scrap. Typically, UBC scrap comprises various non-metallic contaminants, such as plastic films, sand or water, but also various metallic contaminants, such as non-aluminum alloy fragments

Cast aluminum on. In addition to the variety of different impurities, there is another challenge in the treatment of UBC scrap, the scrap to the

Aluminum can collection points and scrap yards are compressed to more or less strongly compacted packages. FIG. 1 shows an example of packages 2 made of UBC scrap, which has a relatively small size

Kompaktierungsgrad have a density of 200 kg / m ³ . The aluminum cans contained in the packages or aluminum can fragments 4 are pressed together relatively loosely. Typically, such packages can be 2 individual

Aluminum can fragments 4 already with relatively little effort, sometimes even by hand, remove. To obtain the package composite, such packages are typically wrapped with a plastic film 6 and may e.g. stored or transported on a pallet 8.

FIG. 2 shows an example of packages 12 of UBC scrap having a high

Have Kompaktierungsgrad with a density of 1200 kg / m ³ . The aluminum cans contained in the packages or aluminum can fragments 14 are strongly compressed. Typically, it is not possible to manually remove aluminum can fragments 14 from such a package 12. In particular, the aluminum can fragments 14 are pressed together so strongly that the packages also hold together without further aids such as plastic films or the like. 3 now shows a diagram of a recycling plant or a

Recycling process for aluminum scrap from the prior art. The

Recycling plant 20 comprises a comminuting plant 22, a sorting plant 24, a paint stripping plant 26 and a melting furnace 28.

For the processing of UBC scrap, the scrap is first in the

Crushing plant 22 given and crushed there. The shredded scrap is then placed in the sorting plant 24 and sorted there to remove contaminants from the scrap. The sorted scrap is then supplied to the paint stripping plant 26 in order to remove varnish layers from the beverage can fragments and finally melted down in the melting furnace 28.

Fig. 4 shows the crushing plant 22 of the recycling plant 20 of FIG. 1 in a schematic representation. The crushing plant 22 is designed as a hammer mill 24. The hammer mill has a driven shaft 28 arranged in a housing 26, on which a plurality of disks 30 with movable hammers 32 are arranged side by side and are connected in a rotationally fixed manner to the shaft 28. Below the shaft 28, a grid 34 is arranged, so that between the shaft 28 with the discs 30 and the grid 34, a crushing space 36 is defined.

In operation, with rotary shaft 28 (see arrow 38), scrap is introduced as volume or mass flow 40 through an inlet 42 into the hammer mill 24 and arrives in the comminution space 36. The effect of the hammers 32 and the friction of the scrap fragments among themselves crushed the scrap until it falls out of the hammer mill 24 through the grid 34 and then as Volumenbzw. Mass flow 44 is transported to the sorting system 24.

For comminution of UBC scrap, the crushing plant 22 has various disadvantages. The greatly differing degrees of compaction of the UBC scrap packets cause the volume or mass flow 40 supplied to the hammer mill 24 to fluctuate greatly. Accordingly, the volume or Mass flow 44 of the crushed scrap, which is fed to the downstream sorting system 24. This leads to a deterioration of the sorting efficiency and to a high susceptibility to failure of the sorting system 24. Furthermore, strongly fluctuating volume or mass flows in the

Hammer mill 24 also to strong density fluctuations in the crushing chamber 36, whereby the degree of comminution of the hammer mill 24 is influenced. A high volume or mass flow 40 leads to a high degree of comminution, so that, for example, a high proportion of fine particles is produced when heavily compacted packages 12 are placed in the hammer mill 24, while the scrap fragments are less crushed in the case of slightly compacted packages 2. This results in addition to the fluctuating volume or mass flow 44 also to a

fluctuating particle size distribution in the volume or mass flow 44, whereby the efficiency of the downstream sorting plant 24 is further deteriorated.

Finally, the crushing plant 22 is also prone to failure, since 12 massive foreign scrap such as cast steel can be hidden in highly compacted scrap packages, which can block the hammer mill 24 or even damage.

5 now shows an embodiment of the invention

Crushing plant and the crushing process according to the invention for comminuting aluminum scrap, in particular UBC scrap. The crushing plant 52 comprises a pre-shredding device 54 for

Pre-shredding of UBC scrap 56. The pre-shredding device 54 is downstream of a comminution device 58, in which the pre-shredded scrap 60 is further comminuted. Furthermore, the crushing plant 52 comprises a

Transport system 62 with a plurality of conveyor belts 64a-d, with the automatically pre-shredded by the pre-shredding device 54 scrap 60 to

Crushing device 58 and that of the crushing device on shredded scrap 66 for further processing, in particular to a

Sorting system is transported.

The pre-shredding device 54 has a housing 68 in which three driven shafts 70a-c are arranged parallel to one another. On the shafts 70a-c, a plurality of rupture discs 72 are arranged in each case, which are rotatably connected to the respective shaft. The shafts 70a-c are driven in operation by a motor (not shown) at lower speeds but high torque. The direction of rotation of the individual shafts 70a-c is indicated in FIG. 5 by the arrows 74a-c

indicated. The rotational speeds of the shafts 70a-c are preferably in a range of 5 to 15 revolutions per minute (rpm) and are preferably different. For example, in operation, the first shaft 70a may be driven at 5 rpm, the second shaft 70b at 7.5 rpm, and the third shaft 70c at 15 rpm. The

Torque per shaft is preferably 200,000 Nm or more. With the speeds mentioned, the pre-comminuting device 54 is therefore referred to as

Slow runner trained.

For feeding the scrap 56 to the pre-shredding device 54, this further has an upwardly open chute 76. In this way, the UBC scrap 56 may be placed on the chute 76 with a polyp gripper 78 from a scrap bin 80 in whole packages 82, for example. The packages 82 then slide down the chute 76 and thus arrive at the rotating one

Rupture discs 72, whereby the packages 82 torn apart and the

Scrap fragments in the packages are at least partially isolated. In this way, in particular, the high density of UBC scrap 56 becomes strong

compacted packages (such as package 12 of FIG. 2).

The pre-shredded scrap 60 falls from the pre-shredding device 54 on the conveyor belt 64a, which is preferably designed as a vibrating conveyor. Due to the vibrations of the conveyor belt 64a, the scrap 60 is distributed more evenly on the belt, resulting in a more uniform volume or mass flow. The pre-shredded scrap 60 is then transported via the further conveyor belts 64b-c to the shredding device 58. The crushing device 58 is in the present case designed as a hammer mill. The hammer mill has a driven shaft 88 arranged in a housing 86, on which a plurality of disks 90 with movable hammers 92 are arranged side by side and non-rotatably connected to the shaft 88. Below the shaft 88, a grating 94 is arranged so that between the shaft 88 with the discs 90 and the grating 94, a crushing chamber 96 is defined. In addition to the grating 94, an anvil 97 in the form of a steel plate, which has the smallest distance from the hammers 92 in comparison with the grating 94, is arranged at the entrance of the comminuting space 96-seen in the direction of rotation of the shaft 88 (see arrow 100) At this point the narrowest gap results.

In operation, the pre-shredded scrap 60 is fed via the transport system 62 through an inlet 98 provided at the housing 86 of the hammer mill 58 and arrives at the shaft 88 (see arrow 100) in the gap between the hammers 92 and the anvil 97 and is crushed there , Subsequently, the scrap 60 passes further into the crushing chamber 96, where it is further comminuted by the force of the hammers 92 and the friction of the scrap fragments with each other. As soon as the scrap 60 has reached a certain size, it falls out of the hammer mill 58 through the grate 94 and onto the conveyor belt 64d as comminuted scrap 66. The shaft 88 of the hammer mill 58 has speeds in the range of 500 to 1000 revolutions per minute and thus provides a

High speed

By pre-crushing the UBC scrap 56 in the pre-shredding device 54 of the crushing device 54 is a much more uniform Volumenbzw. Mass flow scrap supplied as it is in the crushing plant 22 of Fig. 3 and 4 of the case. As a result, on the one hand, it is achieved that a more uniform volume or mass flow of the shredded scrap 66 is achieved, which is supplied to a sorting plant for further processing, for example becomes. Furthermore, the more uniform volume or mass flow leads into the

Crushing device 54 to a constant degree of comminution, so that the grain distribution of the crushed scrap 60 is not subject to large variations. In particular, by tearing highly compacted packages with the pre-shredding device 54, it can be achieved that the maximum density of the volume or mass flow fed to the shredding device 54 is reduced, so that less fine-grained material is produced during comminution. This in turn favors the subsequent further processing, in particular sorting, of the scrap.

Finally, the Vorzerkleinerungsvorrichtung 54 protects the hammer mill 58 from damage by massive foreign scraps, as they are already in the

Pre-shredder 54 remain stuck, but without damaging them, since the Vorzerkleinerungsvorrichtung 54 is a slow-speed.

The comminution plant 52 preferably has a control device 102 with which the pre-comminuting device 54, the transport system 62 and the comminution device 58 can be controlled in order to maintain as constant volume or mass flow as possible of the scrap 60 transported to the comminuting device 58 or of the comminuting device 58 to be transported away scraps 66. For this purpose, the

Control device 102 may be connected, for example, with a sensor for monitoring the motor current for driving the shaft 88. An increasing Volumenbzw. Mass flow in the comminution device 58 can then be detected via an increasing motor current and in this case the control device 102 can reduce, for example, the rotational speed of the shafts 70a-d and / or the transport speed of the transport system 62.

In order to continue to operate the crushing plant 52 during maintenance or temporary failure of the pre-shredding device 54, this has

Transport system 62 between the pre-shredding device 54 and the Crushing device 58 includes an additional feed point 104 that is positioned and configured to allow separate delivery of UBC scrap to the transport system 62. In the present example is as

Zusatzaufgabestelle 104 a prolonged straight portion of the conveyor belt 64b is provided, which is arranged in reach of a Polypgreifers 106 in order to apply this UBC scrap on the conveyor belt 64b can. Preferably, the additional application point 104 is positioned so that it is within reach of the Polypgreifers 78, so that can be dispensed with a second Polypgreifer 106. Fig. 6 shows a diagram representation of an embodiment of the

Recycling plant according to the invention and the inventive

Recycling process. The recycling plant 120 comprises the crushing plant 52 from FIG. 5 with the pre-shredding device 54 and the

Comminution device 58. The comminuting system 52 is followed by a sorting system 122, a paint stripping system 124 and a melting furnace 126.

As explained above in connection with FIG. 5, the UBC scrap can be comminuted with the comminution plant 52 in such a way that the further processing, i. in particular the sorting system 122 supplied crushed scrap on the one hand a more even volume or mass flow and on the other hand a

Consistent grain size distribution than this can be achieved with the crushing plant 22 of the recycling plant 20. This ensures that the further processing of the scrap, that is its sorting in the sorting system 122, the Entlackierung in Entlackungsanlage 124 and the melting in the furnace 126 can be done more effectively and with less interference than in the

Recycling plant 20 from the prior art.

FIG. 7 shows an exemplary embodiment of the method and the installation according to the second aspect of the present disclosure. The plant 200 for processing aluminum scrap comprises a processing station 202 for the treatment of aluminum scrap. In the

Processing station 202 may be, for example, the

Shredder 58 of FIG. 5 act.

Furthermore, the installation 200 comprises a provisioning station 204, which is connected to the

Provision of scrap fragments is set up. For example, the provisioning station 204 may be a buffer storage such as a silo or the pre-shredding device 54 of FIG. 4.

The system 200 further comprises a conveyor 206, which in Fig. 6

exemplified as a conveyor belt is formed. With the conveyor 206, scrap fragments provided by the providing station are transported as stream 208 to the processing station 202 and fed to it. In the

Conveyor 206 may be, for example, the transport system 62 of FIG. 5.

In addition, the plant 200 further includes a flow meter 210 configured to measure a flow rate of the stream 208 at the stream 208 of scrap fragments. For example, the

Throughput meter 210 have a camera system 212, which determines the number of scrap fragments per unit time or covered by the scrap fragments on the conveyor belt 206 surface. Preferably, a separating device 214 is provided for this purpose, which the scrap fragments on the

Transport belt 206 previously isolated.

As an alternative to a camera system 212, a belt scale 216 may also be provided to determine a value for the mass flow. Furthermore, a device for laser triangulation (not shown) may be provided to determine a value for the volume flow of the stream 208. When using a Belt scale or a Lasertriangulationsvorrichtung a previous separation of the scrap fragments is not necessary.

In addition, various throughput measuring devices can also be combined with one another, for example a belt scale 216 for determining a value for the mass flow and a camera system for determining the value for the number of pieces.

The flow rate value determined by the throughput meter 210 is compared in a designated controller 218 with a predetermined value for the throughput. For example, the controller 218 may determine whether the measured value for the flow rate exceeds a predetermined upper limit or falls below a predetermined lower limit. Depending on the result of the comparison, the controller 218 then drives the conveyor 206 and / or the staging station 204. For example, the control device 218 may include a removal device 220 of the

Supply means 204 and the conveyor 206 to drive such that the removal rate of the extraction device 220 and the transport speed of the conveyor belt 206 is increased (decreased) when the measured value for the throughput is too low (too high). Is the staging station 204 a

Pre-shredding device such as the pre-shredding device 54, the controller 218 can also increase their operating speed

(decrease) if the measured value for the throughput is too low (too high).

The following is an example of a possible control of the throughput by the controller 218:

In the controller 218, a throughput window with a lower limit of 200 pieces / second (slice rate) and a first upper limit of 240 pieces / second is set. This throughput window can be, for example, the 5 may be an optimum operating point of an X-ray sorter or, alternatively, the comminution device 58 of FIG. 5, which in the present example represents the processing station 202. Furthermore, a second upper limit value of 260 pieces / second is set in the control device, in which the X-ray sorter or the comminuting device 58 is overloaded.

The staging station 204, for example a silo or silo group (or the pre-shredder 54 of FIG. 5), is set to an initial one

Discharge rate of, for example, 10 t / hour set. The control by the controller 218 may be performed, for example, after a predetermined period of time, e.g. 180 s, after starting the X-ray sorter or the

Crushing device 58 begin.

When the controller 218 determines that the of the

Throughput meter 210 measured value for the throughput for more than e.g. 10 s below the lower limit, the controller 218 controls the extractor 220 (or the pre-grinder 54) so as to increase the discharge rate by, for example, 0.1t / hour. If, after 90 seconds (time from silo discharge to flow meter 210), the throughput is still below the first limit, the output power is increased again, for example by 0.1 t / hour again.

When the controller 218 determines that the of the

Throughput meter 210 measured value for the throughput for more than e.g. 10 s above the first and below the second upper limit, the control device 218 controls the removal device 220 (or the

Pre-shredding device 54) so as to reduce the discharge rate by, for example, 0.25 ton / hour. If, after 90 seconds (time from silo discharge to flow meter 210), the flow rate continues to be in the range between the first and second upper limits, the output power is reduced again, for example by 0.25 t / hour again. When the controller 218 determines that the of the

Throughput meter 210 measured value for the flow rate is above the second upper limit, the controller 218 controls the

Extraction device 220 (or the pre-shredding device 54) so that the discharge power is reduced immediately, for example, by 0.5 t / h, a

To avoid overloading of the X-ray sorter or the crushing device 58. Should after 90 seconds (time from Siloaustrag to the

Throughput meter 210), the throughput further above the second upper limit, the output power is again reduced, for example again by 0.5 t / hour.

Through the throughput control described above, the processing station 202, e.g. the crushing device 58 or a sorting plant, the optimal

Operating point or operated in the optimum operating range. In the

Crushing device 58 as a processing station 202 results in that a desired degree of crushing of the scrap is achieved. In a sorting system as processing station 202, this leads to a good sorting result with the highest possible throughput. By setting the desired degree of comminution or the improvement of the sorting result in the sorting system can be a good

Sorting performance can be achieved with high purity of the sorting result.

Claims

P a n t a n s p r e c h e

Crushing plant (52) for crushing aluminum scrap (56), in particular UBC scrap,

with a crushing device (58) for comminution of

Aluminum scrap, which is designed as a high-speed machine,

wherein the comminution device (58) is preceded by a pre-comminuting device (54) for pre-comminuting aluminum scrap, which is designed as a slow-speed conveyor

characterized,

between the pre-shredding device (54) and the

Crushing device (58) is provided a transport system (62) which is adapted to transport the pre-shredding device (54) pre-shredded aluminum scrap (60) for crushing device (58) z and preferably supply this evenly.

Crushing plant according to claim 1,

characterized in that the crushing device (58) is adapted to crush aluminum scrap substantially hitting and / or shearing.

Crushing plant according to claim 1 or 2,

characterized in that the crushing device (58) a

Einwellenzerkleinerer, a hammer mill or a ring shredder is. Crushing plant according to one of claims 1 to 3,

characterized in that the pre-crushing device (54) thereto is arranged, aluminum scrap substantially tearing and / or shearing, preferably not cutting, to crush.

Crushing plant according to one of claims 1 to 4,

characterized in that the pre-shredding device (54) a

Multi-shaft shredder, especially a two- or three-shaft shredder, is.

Crushing plant according to one of claims 1 to 5,

characterized in that the transport system (62) has a

Vibratory conveyor (64a), which is adapted to the volume flow or mass flow of the of the Vorzerkleinerungsvorrichtung (54)

to homogenize shredded aluminum scrap.

Crushing plant according to one of claims 1 to 6,

characterized in that the transport system (62) between the

Pre-shredding device (54) and the crushing device (58) has an additional application point (104) which is positioned and adapted to allow a separate supply of aluminum scrap to the transport system (62).

Crushing plant according to one of claims 1 to 7,

characterized in that a chute (76) arranged in such a way is provided on the pre-shredding device (54) that the

Pre-shredding device (54) aluminum scrap (56) can be supplied by task on the chute (76).

9. Crushing plant according to one of claims 1 to 8,

characterized in that the crushing plant (52) has a

Control device (102) for controlling the crushing plant (52) which is preferably arranged to control the comminution plant according to a method according to one of claims 11 to 14.

Recycling plant (120) for the treatment of aluminum scrap, in particular UBC scrap, comprising a crushing plant (52) according to one of

Claims 1 to 9.

Recycling plant according to claim 10,

characterized in that the recycling plant (120) one of

Crushing plant (52) downstream sorting system (122), which is preferably for a sensor-based sorting, in particular LIBS-based sorting, is set up.

Crushing process for crushing aluminum scrap (56), in particular UBC scrap, in particular using a

Crushing plant (52) according to one of claims 1 to 9,

in which a quantity of aluminum scrap (56) is pre-shredded with a pre-shredding device (54) in the form of a slow-motion and in which the pre-shredded aluminum scrap (60) is comminuted further by means of a comminuting device (58) designed as high-speed, characterized in that

in that the pre-shredded aluminum scrap (60) is controlled by the comminution device (58), in particular with a given volume flow or mass flow.

Crushing method according to claim 12,

characterized in that pre-shredding device (54)

Aluminum scrap is supplied in packets, especially in different

Kompaktierungsgraden.

14. crushing method according to claim 12 or 13,

characterized in that the pre-shredded aluminum scrap (60) by means of a transport system (62) to the crushing device (58) is transported.

15. A recycling process for the treatment of aluminum scrap (56), in particular UBC scrap, preferably using a recycling plant (120) according to claim 10 or 11,

wherein a quantity of aluminum scrap (56) is comminuted by a crushing method according to any one of claims 12 to 14, and

in which the shredded scrap (66) further processed, in particular sorted.