Abstract:
The aim of the invention is to eliminate vibrations and resonances, occurring in the constructional system in a device with a motor-driven system for the separation of non-magnetisable metals, in particular non-ferrous metals and the ferrous fractions in a solids mixture, by means of a drum ( 2 ) mounted on and rotating about a stator ( 1 ), within which a magnetic rotor ( 4 ) fitted with permanent magnets ( 3 ) is eccentrically arranged and mounted on said stator ( 1 ). Said aim is achieved whereby the stator ( 1 ) is provided with a balance weight ( 1.1 ) for mass balance.

Description:
TECHNICAL FIELD  
         [0001]    The invention relates to a device with a system driven by a motor for separating non-magnetizable metals, in particular non-ferrous metals, and ferrous fractions that are present, from a solid mixture, with a drum that is supported on a stator and rotates around the stator, with a rotating magnet rotor fitted with permanent magnets eccentrically arranged in the rotating drum and supported in the stator. The invention also relates to a method for operating the device.  
         STATE OF THE TECHNOLOGY  
         [0002]    Such devices and methods for separating non-magnetizable metals are known in the art.  
           [0003]    For example, DE-C1-38 23 944 proposes a magnet system that is driven inside a belt drum with a rotation speed that is higher than the rotation speed of the belt drum. The outside diameter of the magnet system is herein smaller than the unobstructed inside diameter of the belt drum, and more importantly, the magnet system is arranged eccentrically in the belt drum.  
           [0004]    DE-C1-38 17 003 discloses an improvement of this device, whereby the position of the eccentrically arranged magnet rotor in the quadrant of the material discharge zone and the effective range of the alternating magnetic field produced by the magnet rotor can be adjusted in the radial direction.  
           [0005]    In order to improve the separation effect of the aforedescribed solid mixtures, after initial separation of the Fe-fraction, with respect to non-ferrous metals, DE-C2-195 21 415 constructively combines several conventional technical means, ranging from the feed regions of the solid mixture to the conveyor and discharge regions and the separation zones formed by the trajectories, to improve the purity of the recovered graded concentrates of the various material fractions.  
           [0006]    The search for precious materials in recycling operations is still ongoing and new problems have arisen.  
           [0007]    When non-magnetizable metals, such as non-ferrous metals, are separated from solid mixtures which are obtained after separation of the Fe-fraction, for example from a shredder light fraction, the purity of the recovered graded non-ferrous metal fraction should be increased not only to fetch a higher price, but also to economically separate mass flows of solid mixtures into reusable fractions.  
           [0008]    It has been observed in practice that the aforedescribed solid mixtures still contain residual Fe—even after prior Fe-separation.  
           [0009]    Processing mass flows of solid mixtures with the aforedescribed devices has led, among others, to the design of extremely wide drums and magnet rotors that are eccentrically arranged in the drums and rotate with the drums. This causes oscillations which negatively impact both the system structure and the separation effect.  
         DESCRIPTION OF THE INVENTION  
         [0010]    It is an object of the invention to provide a device of the aforedescribed type, which can meet the requirements for industry-scale separation of non-magnetizable metals and any remaining Fe-fractions from solid mixtures, in particular after the Fe-fraction has been separated from the shredder light fraction. More particularly, the purity of the recovered graded non-ferrous metals has to be guaranteed, while the remaining Fe-fractions still have to be separated. A particular problem to be solved is a reduction and possible elimination of oscillations that occur in particular with extremely wide drums and possibly also with the connected conveyor belt systems as well as the elimination of corresponding resonances in the structure. The related method is intended to ensure the purity of the recovered graded concentrates.  
           [0011]    The object is solved by the characterizing features of the device claims 1 to 19 and the method claim 20.  
           [0012]    The invention will be described herein after with respect to a complex embodiment, wherein different modifications of the device are illustrated which, when taken together, contribute to a solution of the problem. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]    The drawings show in  
         [0014]    [0014]FIG. 1 a longitudinal cross-section through a drum with a magnet rotor eccentrically arranged in the drum and a balance weight according to the invention,  
         [0015]    [0015]FIG. 2 the cross-sectional view of FIG. 1 with the balance weight according to the invention and a transport magnet,  
         [0016]    [0016]FIG. 3 a schematic diagram of the device in a conveyor belt system with a connected separation apex and means for adjusting the separation apex,  
         [0017]    [0017]FIG. 4 a schematic diagram of the conveyor belt system with a circumferential projection disposed on the conveyor belt and associated separation apexes arranged subsequent to the conveyor belt regions, and  
         [0018]    [0018]FIG. 5 a partial cross-section through a drum shell.  
     
    
     BEST MODE FOR CARRYING OUT THE INVENTION  
       [0019]    As depicted in FIGS. 1 and 2, the device according to the invention includes a drum  2  which is supported on a stator  1  and rotates about the stator  1 . A rotating magnet rotor  4  fitted with permanent magnets  3  is eccentrically arranged in the drum  2  and supported in the stator  1 . The functionality and operation of such device for separating non-magnetizable metals from a solid mixture is extensively described in the references addressing the state-of-the-art.  
         [0020]    Since the separation effect in such devices is produced by tilting the magnet rotor  4  that is eccentrically arranged in the stator  1 , a balance weight  1 . 1  is arranged on the stator  1  for mass balance. This balance weight  1 . 1  simultaneously operates as an oscillation damper, in particular when an extremely wide drum  2  and/or conveyor belt system  5 ,  5 . 1  are used, as illustrated in FIGS. 3, 4 and  5 .  
         [0021]    To separate from the solid mixture the remaining Fe-fraction in addition to the usually separated non-ferrous metals, the balance weight  1 . 1  is implemented as an assembly with a transport magnet  1 . 2  or as a magnet, wherein the shape of the balance weight  1 . 1  is matched to the shape of the drum  1 .  
         [0022]    To optimize the efficiency of the magnetic field and hence the separation effect, the shape of the balance weight  1 . 1  is matched to the shape of the magnetic field to be generated, and can have a technologically advantageous sickle-shaped cross-section.  
         [0023]    Permanent magnets  3  of different shapes, dimensions and polarities in both the radial and axial direction of the magnet rotor  4  can additionally be fitted to the magnet rotor  4 .  
         [0024]    Such device implementation alone can satisfy the requirements for solving the problems addressed by the invention.  
         [0025]    If the drum  2  with the magnetic rotor  4  that is arranged eccentrically in the drum is incorporated as a header drum in a continuous conveyor belt system  5  with a conveyor  5 . 1  that conveys the solid mixture (FIGS. 3, 4), followed by a separation apex, then a means  7 , for example a camera, that recognizes the corresponding composition of the separated fraction the separation apex  6  can be provided, wherein the means  7  cooperates with an adjusting device  9  which adjusts the separation apex  6  to a corresponding concentrated graded composition of the separated fraction.  
         [0026]    The separation effect is also enhanced in that  
         [0027]    the rotation speed of the drum and  
         [0028]    the rotation speed of the magnet rotor  
         [0029]    can be matched to the flow rate and/or composition of the solid mixture and that both the angle of the magnet rotor  4  about the rotation axis of the drum  2  as well as the distance of the axis of the magnet rotor  4  relative to the rotation axis of the drum  2  can be adjusted to obtain the desired trajectories for the non-ferrous metals to be separated.  
         [0030]    For a very wide conveyor belt system  5  and conveyor belt  5 . 1 , it may be advantageous for certain applications for separating solid mixtures to divide the conveyor belt system  5 . 1  into two regions with a circumferential projection  10 , to arrange a dedicated separation apex  6 . 1 ,  6 . 2  after these regions, and to adjust the separation apexes ( 6 . 1 ,  6 . 2 ) independently of each other, so that different materials of solid mixtures can be subjected to pre-cleaning and post-cleaning.  
         [0031]    As shown in FIG. 5, the conveyor belt  5 . 1  can be guided on a particularly wide drum  2  and the conveyor belt  5 . 1  can be prevented from leaving the running surface and/or the drum shell  2 . 1  on drum  2 , by providing (see FIG. 5) a bead-like guide projection  11  in the conveyor belt  5 . 1 . The guide projection  11  runs and is guided in a circumferential groove  12  of the drum shell  2 . 1 .  
         [0032]    To improve the separation quality, the upper edges of the separation apexes  6 ,  6 . 1 ,  6 . 2  can be implemented as a rotating cylinder (not shown).  
         [0033]    In useful embodiments of the device of the invention, a stripping unit  8  (FIG. 3) can be arranged on the outer shell  2 . 1  of the drum  2  to prevent harmful fractioned particles from entering between the conveyor belt  5 . 1  and the drum shell  2 . 1 .  
         [0034]    For practical industrial applications, it is important to provide a method which guarantees the separation quality in the event of a power failure until the drive system comes to a halt. According to the method of the invention, the energy of the still rotating magnet rotor  4  is used for the motor (not shown) to drive the conveyor belt system  5 , in order to drive the drum  2  with the other motor (not shown) of the magnet rotor  4  which now operates as a generator, long enough so that the remaining solid mixture, which was left on the conveyor belt system  4  when the power failed, can be separated.  
       INDUSTRIAL APPLICABILITY  
       [0035]    The invention provides the industry with a device and a method for separating non-magnetizable metals and Fe-fractions from a solid mixture, which in addition to a compact device configuration provides a high separation quality and purity of the recovered graded fractions.  
                                             List of Reference Numerals                                    1 =   stator           1.1 =   balance weight           1.2 =   transport magnet           2 =   drum           2.1 =   drum shell           3 =   permanent magnets           4 =   magnet rotor           5 =   conveyor belt system           5.1 =   conveyor belt           6 =   separation apex           6.1 =   first separation apex           6.2 =   second separation apex           7 =   means, camera           8 =   stripping unit           9 =   adjusting device           10 =   circumferential projection           11 =   guide projection           12 =   guide groove