JP3955927B2 - Eddy current type nonferrous metal separator - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an eddy current type non-ferrous metal material separation device for non-ferrous metal materials for separating non-ferrous metal materials . More specifically, the present invention relates to an eddy current type non-ferrous metal material separation device that separates non-ferrous metal materials by repulsive force due to eddy current generated in the metal material . More specifically, the present invention relates to a method of combining magnet elements that are fixed on the outer peripheral cylindrical surface of a rotor and generate an eddy current in a metal object to provide a magnetic field.
[0002]
[Prior art]
Industrial waste, waste home appliances, and waste buildings contain many valuable metals, and it is important to separate and reuse the metal. Moreover, there are metal objects in foodstuffs and foodstuff materials that contain all impurities, and removal of the metal objects is also desired. Among these metal objects, ferrous iron, nickel, cobalt, stainless martensite, etc. can be adsorbed and removed with magnets, etc., but non-ferrous metal objects such as aluminum, copper and brass are Separation and removal cannot be done with a magnet alone.
[0003]
As a method and apparatus for separating these non-ferrous metal objects, an eddy current type is known. When an electric conductor is placed in a time-varying magnetic field, an induced electromotive force is generated inside the metal due to the influence of the time-varying magnetic field, and thus an eddy current flows. The induced magnetic field due to this eddy current interacts with the original magnetic field to generate repulsive force. The eddy current type metal separator utilizes the repulsive force caused by this eddy current.
[0004]
The operating principle of the eddy current type non-ferrous metal material sorting device will be described with reference to FIG. FIG. 6 (a) illustrates the principle of repulsion due to eddy currents. When the conductor penetrates the magnetic flux, electromagnetic induction electromotive force is generated in the conductor due to temporal change of the magnetic flux, and eddy current flows. This eddy current creates an induced magnetic field that interacts with the original magnetic field. In Lenz's law, eddy currents are generated in a direction that cancels the original magnetic field.
That is, when the magnetic flux penetrating through the conductor increases with time, the direction of the magnetic flux line of the induction magnetic field is opposite to the direction of the magnetic flux line of the original magnetic field and repels each other. In the opposite case, the induced magnetic field attracts the original magnetic field. As described above, the repulsive force generated when the induced magnetic field repels the original magnetic field becomes a source of force that causes the conductor to jump off. This repulsion works in exactly the same way for a conductor placed in a changing magnetic field.
[0005]
FIG. 6B illustrates the principle of an eddy current type non-ferrous metal material separation device. The object to be sorted is carried on a belt that moves at a constant speed and is carried to a rotor that provides an alternating magnetic field. The rotor rotates at high speed relative to the belt. A permanent magnet is fixed on the outer peripheral cylinder of the rotor, and an alternating magnetic field is generated for the objects to be sorted on the belt as the rotor rotates.
Based on the above-described principle, an eddy current is generated in the non-ferrous metal object, and is jumped off. When jumping and falling, the distance varies according to the type and size of the metal. If the objects to be sorted are all the same size, the distance to fall depends on the type of metal, so it can be sorted for each metal. The falling distance depends on the initial bounce force and the density of the objects to be sorted.
[0006]
The induced electromotive force e generated in the selection object is expressed by the following equation.
e = -kdB / dt (Formula 1)
Here, B is the magnetic flux line density of the magnetic field, k is a constant, t is time, and d is a differential operator.
The eddy current i flowing in the object to be sorted is as follows.
i = e / R =-(k / R) dB / dt (Formula 2)
R: electrical resistance of the object to be selected This eddy current i creates an induced magnetic field proportional to it. Eddy currents are generated so that this induced magnetic field is in a direction that cancels the change in the original magnetic field (Lenz's law).
[0007]
When the sorted matters is not the temporally size change of the magnetic flux penetrating, the induced magnetic field and the original magnetic fields repel. The magnitude of this repulsive force depends on the change in magnetic flux density that passes through the object to be sorted, as is apparent from the above formulas (1) and (2). In order to increase the repulsive force, it is necessary to increase the change in magnetic flux density.
[0008]
As shown in FIG. 4A, the conventional magnets are arranged such that the N poles and S poles of the magnet elements are alternately directed outward when the permanent magnet is mounted on the outer peripheral cylinder of the rotor. . In this conventional structure, there are the following methods for increasing the change in magnetic flux density. 1. 1. Increase the relative speed between the object to be selected and the permanent magnet element. 2. Use permanent magnet elements with strong magnetic fields. This is a method of increasing the volume of the object to be sorted.
[0009]
In the case of the above-described method 1, the belt speed is increased, the rotational speed of the rotor is increased, or both. In the case of the method 2 described above, the price of the apparatus increases as the powerful magnet is used, and is not suitable for mass production. In the case of the method 3 described above, there is a disadvantage that a small volume cannot be selected.
[0010]
As described above, in the conventional structure, the magnetic field lines have a parabolic shape from the north pole to the south pole of the magnet element, and the number of magnetic field lines through which the object to be sorted passes is limited. By passing the object to be sorted as close as possible to the permanent magnet element, the number of magnetic fluxes penetrating increases, but there are structural limitations at the actual machine stage.
[0011]
Further, in the conventional structure, when the volume of the object to be sorted becomes small, the object to be sorted is jumped back from the vicinity of the rotor (backflowing). This is because the repulsive force with which the volume is reduced becomes larger than its own weight and jumps off.
[0012]
[Problems to be solved by the invention]
The present invention has been made based on the technical background as described above, and achieves the following object. An object of the present invention is to provide a more efficient eddy current type nonferrous metal sorting apparatus. Another object of the present invention is to provide an eddy current type non-ferrous metal sorter that can sort a smaller volume than that which could not be sorted by the combined structure of permanent magnet elements. Still another object of the present invention is to provide a belt conveyor structure in which the objects to be sorted do not flow in the reverse direction on the belt conveyor.
[0013]
[Means for Solving the Problems]
In order to achieve the above object, the present invention employs the following means. The above object is achieved by arranging the permanent magnet elements so that the magnetic lines of force generated from the permanent magnet elements are generated in the radial direction of the rotor. The arrangement is as follows. A permanent magnet element is arranged on the outer peripheral cylinder of the rotor so that the north and south poles are alternately directed outward in the radial direction of the rotor, while another magnetic element is directed to the outside of the magnet element. Line up side by side so that the same pole is facing. A trapezoidal magnet is inserted between the magnetic spacers sandwiched between the side surfaces of the magnets on which the magnetic poles are alternately arranged. The trapezoidal magnet magnetic poles are attached so that the upper part is repelled and the lower part is attracted to the magnetic poles of the left and right magnets. In other words, the direction of the magnetic pole of this trapezoidal magnet is directed to the tangential direction of the circumference of the rotor, and the direction of this magnetic pole is arranged to face the same magnetic pole as the outer magnetic pole of the adjacent permanent magnet element. . In this arrangement, since the same poles of the magnet elements face each other, they repel each other and the magnetic lines of force are directed outward in the radial direction. In addition, in order to prevent the object to be sorted flowing on the belt conveyor from flowing in the reverse direction due to the influence of repulsive force, the above object is achieved by lowering the belt conveyor. In order to improve the magnetic flux density of the magnetic field provided by the eddy current generator, the present invention is directed to the arrangement of the magnet elements mounted on the outer peripheral cylinder of the rotor and the belt conveyor so that the small conductor does not flow backward due to repulsive force due to eddy current It is characterized in that it consists of making the downhill state.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Embodiment 1 of the Invention
Next, an embodiment of the present invention will be described. FIG. 1 is an overall view showing a first embodiment of the present invention. FIG. 2 is a front sectional view of the rotor portion. FIG. 3 is a diagram illustrating an arrangement of magnet elements in the circumferential direction. As shown in FIG. 1, the non-ferrous metal sorting apparatus 1 includes a frame 2 for housing the non-ferrous metal sorting apparatus 1, a belt conveyor 3 mounted thereon, a motor 4, a rotor 5, and a hopper. 6 etc. The frame 2 is the main body of the apparatus. The belt conveyor 3 is a transfer device that transfers an object to be sorted. The motor 4 is for rotating the rotor 5 via a timing belt or the like.
The rotor 5 provides a changing magnetic field for sorting non-ferrous metals. The hopper 6 is used for supplying the objects to be sorted to the belt conveyor 3 in a fixed amount. A tail pulley 7 is disposed on the belt conveyor 3 on the side opposite to the rotor 5. The tail pulley 7 incorporates a built-in motor (not shown), and the belt conveyor 3 is driven by this motor.
Further, the non-ferrous metal material sorting device 1 is entirely covered with a cover 8. Inside the cover 8, a sorting box 9 for storing the sorted non-ferrous metal objects is arranged. On the sorting box 9, a partition wall 10 for sorting is arranged.
[0015]
FIG. 2 shows the magnet elements arranged on the outer periphery of the rotor 5. The magnet element 23 is a permanent magnet, which is a neodymium permanent magnet in the present embodiment. FIG. 3 is a diagram illustrating an arrangement of magnet elements in the circumferential direction. The magnet element 23 is composed of two types: a square hexahedron magnet element 24 and a hexahedron trapezoidal magnet element 25. On the outer periphery of the rotor 5, 18 cylinders 20 are formed, and one surface of the magnet element 24 is fixed on each 18 surfaces. The magnet element 24 is arranged in the axial direction of the rotor 5. The magnet element 24 is fixed so that its magnetic pole faces outward along the radial direction from the center of the rotor 5. In addition, the magnetic poles directed to the outside of the two fixed to adjacent surfaces are opposite to each other. That is, the magnetic poles facing the outside of the one row of magnet elements 24 are alternated as N poles, S poles, N poles, and so on. As shown in FIGS. 3 and 4, the magnet elements 24 are alternately arranged, the magnetic spacers 26 are sandwiched between the side surfaces, and the trapezoidal magnet elements 25 are inserted therebetween.
[0016]
Magnet elements 25 are arranged between the magnet elements 24 (first permanent magnet elements) in a row. The magnetic pole of the magnet element 25 (second permanent magnet element) is arranged toward the same magnetic pole side of the magnet element 24. With this arrangement, the magnetic pole on the rotor 5 side of the magnet element 24 attracts the magnetic pole of the magnet element 25, and the opposite magnetic pole repels the magnetic pole of the magnet element 25. As a result, a force that pushes the magnet element 25 toward the rotor 5 works and a fixing operation such as screwing is not required.
The 18 cylinders 20 are made of yokes. Therefore, the magnetic lines of force generated from the magnetic poles on the rotor side of the magnet elements 24 and 25 do not leak outside through only the yoke. Magnetic field lines emanating from the magnetic poles facing outward leak to the periphery of the rotor 5 and provide a magnetic field in the radial direction of the rotor 5.
4 (a) and 4 (b) show the state of the magnetic lines of force, FIG. 4 (a) shows the state of the magnetic lines of force of the conventional magnet arrangement, and FIG. 4 (b) shows the state of the magnetic lines of force of the present invention. It is the result of measuring the state with a gauss meter. As shown in b). All lines of magnetic force generated from the magnetic poles of the magnet elements 23 are directed outward. Therefore, it is clear that the number of magnetic field lines penetrating the object to be sorted is significantly increased as compared with the conventional structure.
[0017]
The objects to be sorted supplied from the hopper 6 are carried on the belt conveyor 3 and carried to the rotor 5. In the vicinity of the rotor 5, an induced electromotive force is generated in the object to be sorted due to the influence of the magnetic field that is changed by the rotation of the rotor 5 by the permanent magnet 23, and an eddy current flows. Eddy currents create an induced magnetic field. This induced magnetic field is in a direction that cancels the original magnetic field (Lenz's law). Therefore, the induced magnetic field and the original magnetic field interact.
When this interaction repels, the object to be sorted is skipped. The to-be-sorted items fall while falling freely. The distance to fall depends on the type and size of the metal object. If the sizes of the objects to be sorted supplied from the hopper are all the same, the objects to be classified can be classified by type according to the above-mentioned falling distance.
[Embodiment 2 of the Invention]
FIGS. 5A and 5B show Example 2 of the present invention, FIG. 5A is a plan view, and FIG. 5B is a front view. The configuration of the second embodiment is basically the same as that of the first embodiment. The difference is that the belt conveyor 33 that conveys the objects to be sorted has a structure with an inclination just before the rotor. The functions of the other components are exactly the same as in the first embodiment.
That is, the auxiliary roller 70 is disposed immediately before the rotor 5, and the support members 71 are disposed at both ends of the auxiliary roller 70 to support the auxiliary roller 70. By tilting the belt conveyor 33 so that the belt conveyor 33 protrudes upward by the auxiliary roller 70, the object to be sorted is moved away from the rotor 5 before sorting, so that it is blown in the reverse direction of the belt conveyor 33 under repulsive force. This is to prevent rolling.
When the weight of the object to be sorted was reduced, while approaching the rotor 5, it was repelled and flowed backward or flowed. Therefore, such a phenomenon does not occur when the belt conveyor 33 is inclined in the vicinity of the rotor 5. When the objects to be sorted fall one by one from the slope, they may be jumped backward, but they are caught in the objects to be sorted flowing from behind, so that the above-described problems do not occur.
[0018]
【The invention's effect】
According to the present invention, the following effects can be obtained. The magnet elements are arranged on the outer circumference of the rotor so that the north and south poles are alternately directed outward with respect to the axial direction of the rotor. By placing the poles facing each other, the magnetic field lines created by the magnet elements are temporarily not flat, and as the rotor rotates, the change in magnetic flux density increases and the eddy current in the object to be selected increases. As the repulsive force increases, the separation efficiency of the objects to be sorted increases, and smaller items can be sorted. In addition, by making the portion on the rotor side of the belt conveyor, which is a means for carrying the object to be sorted, in a slope shape, the object to be sorted does not flow backward from the rotor part, and the efficiency of sorting is improved.
[Brief description of the drawings]
FIG. 1 is an overall view showing a first embodiment of the present invention.
FIG. 2 is a front sectional view of a rotor portion.
FIG. 3 is a diagram illustrating an arrangement of magnet elements in a circumferential direction.
4 (a) and 4 (b) show the state of magnetic lines of force, FIG. 4 (a) shows the state of magnetic lines of force of a conventional magnet arrangement, and FIG. It is a figure which shows the state of the magnetic force line of invention.
FIGS. 5 (a) and 5 (b) show Example 2 of the present invention, FIG. 5 (a) is a plan view, and FIG. 5 (b) is a front view.
FIGS. 6A and 6B are diagrams showing the principle of eddy current generation and the principle of an eddy current type metal object sorting apparatus.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Nonferrous metal sorter 2 ... Frame 3 ... Belt conveyor 4 ... Motor 5 ... Rotor 6 ... Hopper 7 ... Dale pulley 8 ... Cover 21 ... Main shaft 22 ... Outer cylinder 20 ... yoke ring 23 ... Permanent magnet element 24 ... Magnet Element 25 ... Trapezoid magnet 26 ... Magnetic spacer

Claims (3)

There is provided eddy current generation means for attaching a permanent magnet element (23) to the outer periphery of the rotor (5) and generating an eddy current for driving the rotor (5) to generate an alternating magnetic field to separate non-ferrous metal objects. An eddy current type non-ferrous metal fractionation device comprising:
The permanent magnet element (23) of the eddy current generating means comprises a first permanent magnet element (24) and a second permanent magnet element (25),
The first permanent magnet elements (24) are arranged such that S poles and N poles are alternately arranged so that the magnetic poles are directed outward along the radial direction from the center of the rotor (5) ,
The second permanent magnet element (25) is arranged with the magnetic spacer (26) sandwiched between the side surfaces of the two first permanent magnet elements (24), and the magnetic poles of the second permanent magnet element (25) are arranged. Of the second permanent magnet element (25) is adjacent to the second permanent magnet element (25), and the direction of the magnetic pole of the second permanent magnet element (25) is adjacent to the second permanent magnet element (25). arranged to face the outer magnetic pole and the magnetic poles of the first permanent magnet elements (24), by the magnetic force lines generated magnetic lines of force generated from the second permanent magnet element (25) from the first permanent magnet element (24) An eddy current type non-ferrous metal fractionation device characterized by being repelled and directed to the outside of the rotor (5). In the eddy current type non-ferrous metal fraction separation device according to claim 1 ,
The first permanent magnet element (24) is a six-sided rectangular parallelepiped,
The second permanent magnet element (23) has a six-sided trapezoidal shape. An eddy current type non-ferrous metal material separation device. In the eddy current type nonferrous metal fraction separation device according to claim 1 or 2,
A non-metallic belt conveyor (3 , 33 ) for transferring non-ferrous metal objects to the eddy current generating means;
Conveying means composed of a driving device for driving the belt conveyor (3 , 33 ),
The belt conveyor (3 , 33 ) is in a downhill state with an inclination just before the rotor (5) before the eddy current generating means.

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