EP0342330B1 - Device for separating non magnetic metals from a solid mixture - Google Patents

Description

The invention relates to a device for separating non-magnetizable metals, in particular non-ferrous metals, from a solid mixture by means of a rotating drum in which a rotating magnetic rotor equipped with permanent magnets is arranged eccentrically.

The so-called eddy current separation can be carried out with the aid of such a device, which is known from the older, subsequently published EP-A-0 339 195. The feed material is fed to the magnet rotor, which has a significantly smaller outside diameter than the inside diameter of the rotating drum, by means of a conveyor belt or belt. As soon as the feed material comes into the effective range of the alternating magnetic field, eddy currents are induced in the electrically conductive components of the mixture to be separated, which build up their own magnetic fields that are opposed to the generator field and thereby accelerate these components by electromagnetic forces relative to the other components of the mixture. Eddy current separation allows non-ferromagnetic, highly electrically conductive substances, such as aluminum and copper, to be separated from non-ferrous solid mixtures and non-ferrous metal / non-metallic solid mixtures, such as automobile shredder rubble, electronic scrap and the like. If ferromagnetic parts are contained in this material, the eddy current separation can be preceded by a magnetic separation in order to remove ferromagnetic parts beforehand. Eddy current separation is also useful Sorting and classification stages upstream, because the greatest possible advance enrichment and fractionation of the feed material has a positive effect on the separation success.

In the case of an eddy current separator known from JP-A-57 119 856, the magnetic forces exerted on the constituents contained in the solid mixture supplied via a slide are to be increased. For this purpose, a second drum is located at a distance above a lower drum, which eccentrically receives the magnetic rotor equipped with permanent magnets, and concentrically receives a magnetic rotor equipped with permanent magnets. Both the drums and the magnetic rotors rotate in opposite directions.

Finally, DE-C-915 921 discloses a drum magnetic separator with a magnet system which is fed by direct current and rotates within the drum from non-magnetic material. The magnet system consists of a magnet wheel designed in the manner of a motor armature, which rotates independently of the drum rotating in the same or opposite sense. The magnet wheel can be arranged eccentrically or concentrically in the drum.

In a separating device known from DE-OS 34 16 504, a solid mixture for separating the ferromagnetic portion is first passed through a conveyor belt below a magnetic separator and then from the conveyor belt for separating the non-ferrous metals fed to a slowly rotating outer drum. A fast rotating rotor equipped with permanent magnets is arranged concentrically inside the outer drum. The permanent magnets extend uniformly along the axis of rotation of the magnetic rotor and are arranged there at a large distance from one another in order to ensure that a magnetic field which forms between the poles of the permanent magnets acts as far as possible outside the drum. With this known device, higher throughputs with greater layer heights of the supplied solid mixture should be possible compared to other eddy current separation processes in that the separating forces of the alternating magnetic field act on the solid mixture at the point in time at which the gravitational forces have no or only a slight effect.

The solid mixture reaches the area of the alternating magnetic field very early, namely before the upper vertex of the outer drum. The non-ferrous metal parts are thus additionally accelerated very early, essentially tangentially in the conveying direction. These parts therefore pass into a throwing parabola much earlier than the non-conductive material parts, ie they lose contact with the drum at an early stage.

However, the acceleration of the non-ferrous metal parts is not sufficient to deflect the throwing parabola, which begins at the apex of the drum, far enough beyond the drum radius. It is therefore not possible to rule out disabilities with the electrically non-conductive parts which are either still lying on the drum surface or are being detached due to gravity. The non-ferrous metal parts already detached at the apex of the drum due to the force of the magnetic field rather hit the electrically non-conductive parts conveyed by the outer drum, so that mutual hindrances occur. On the one hand, conductive parts to be deflected are braked by the non-conductive parts and, on the other hand, non-conductive parts are undesirably accelerated by contact with the conductive non-ferrous metal parts. As a result, incorrect discharges cannot be avoided in both grades, i.e. electrically non-conductive parts also get into the collection area of the non-ferrous metal parts and vice versa.

US Pat. No. 3,448 also describes a device for separating substances which are less electrically conductive from electrically good conductors by means of a magnetic rotor arranged concentrically in a rotating outer drum, the magnets of which are arranged alternately with a north and a south pole on the periphery of the rotor body 857 became known. The solid mixture intended for separating the constituents is fed to the outer drum of the magnetic rotor either from a belt conveyor running a short distance above the outer drum or by means of a conveyor belt which wraps around the outer drum. As soon as the solid mixture reaches the effective range of the alternating magnetic field of the magnetic rotor, the magnetic forces accelerate the electrically well-conductive substances to a more distant one Trajectory than the less electrically conductive substances, so that due to the different trajectories a separation of these components can be achieved.

The invention has for its object to provide a device of the type mentioned, which allows an improved mode of operation when separating in particular non-ferrous metals from a solid mixture.

This object is achieved in that the position of the axis of rotation of the magnetic rotor in the quadrant of the material discharge zone and thus the effective range of the alternating magnetic field generated by the magnetic rotor can be adjusted by radial adjustment. It is also proposed that the magnetic rotor can be pivoted about the axis of rotation of the drum. Due to the specific arrangement and position of the magnetic rotor in the drum and the combined adjustability of the effective range of the alternating magnetic field by the aforementioned radial displacement and / or pivoting of the magnetic rotor around the axis of rotation of the drum and the possible adjustment of the magnetic rotor on any cam tracks, which for certain Material granulations can be of importance, the greatest possible effect of the eddy current separation can be exhausted, so that the full force of the magnetic field floods the non-ferrous metals in the area referred to below as the "material discharge zone"; the Material discharge zone is reached when the material to be separated on the curved line formed either directly by the drum or by the conveyor belt wrapping around the drum starts to slide or fall due to the force of gravity, so that mechanical rejection forces combine with the repulsive ones that act as late as possible Forces of the magnetic field for the non-ferrous metals the greatest deflection of the throwing parabola and thus a targeted separation from the other mixture components results.

With the stepless or step-wise adjustability of the rotor shaft or the axis of rotation of the magnetic rotor, the effective range of the alternating magnetic field on the mixture in the entire quadrant of the discharge zone can be specifically aimed at a specific and more narrowly defined area on the drum. The invention is based on the knowledge that a disruptive, mutual hindrance of the parts of the solid mixture to be separated is almost ruled out if the mixture to be separated has already been conveyed as far as possible beyond the apex of the drum, for example by means of a conveyor belt up to this Point is moved forward, and on the other hand, the repulsive forces act on the non-ferrous metals most strongly when the mixture is just in the material discharge zone. Here, a magnetic rotor to be adjusted concentrically on a radius around the drum axis of rotation detects an adjustment range which meets all operating requirements.

The setting or shifting of the effective range of the alternating magnetic field can advantageously be favored by adjusting the peripheral speed of the drum, because of changing the peripheral speed of the drum, for example between 1 m and 3 m, due to the set position of the axis of rotation of the magnetic rotor in the quadrant of the material discharge zone / sec, can be determined by the composition of the Shift the solid material mixture dependent, variable material discharge zone to the area of the drum in which the force of the permanent magnets is greatest under the given circumstances. The higher the peripheral speed, the closer the material drop zone approaches the top vertex of the drum.

Such an adjustment of the eccentric position of the magnet rotor in the quadrant of the discharge zone of the drum is proposed, in which the air gap between the magnet rotor and the drum is the smallest in the area of the material discharge zone. The particular position of the material discharge zone for a given curvature of the drum depends on the peripheral speed of the drum, the type and grain size composition of the solid mixture and the friction between the conveyor belt or the outer surface of the drum and the mixture to be separated. Since these criteria can be very different, changing conditions are taken into account by adjusting the magnetic rotor accordingly; this can preferably be set in an angular range of 75 ° from the vertical center plane through the drum axis. Depending on the coefficient of friction of the mixture and the curvature of the drum, the material discharge zone is expediently in a range of approximately 15 to 50 ° to the vertical running through the axis of rotation of the drum. If, for example, the angle between the vertical through the axis of rotation of the drum and the connecting line of this axis of rotation with the axis of rotation of the rotor shaft were chosen too small, the force of the eddy current would have a full effect on the non-ferrous metals even before the material discharge zone. The non-ferrous metals would thus accelerate very early, deviate from the desired large deflection of the throwing parabola and then in fall a collecting container which is intended for the inferior mixture components which are not influenced by the alternating magnetic field and are therefore not intended for a deflecting parabola deflected in the conveying direction. Due to the repulsion of the non-ferrous metals in the conveying direction, that is to say radially to the curved line of the drum, the conveying width of the eddy current separating device according to the invention is not subject to any restriction.

It has been found that very good results can be achieved with a magnet rotor with at least two rows of permanent magnets arranged in the longitudinal direction of the rotor shaft. In view of the considerable centrifugal forces, the permanent magnets to be carefully attached to the rotor body - for example by gluing or screwing on - with the minimum number of poles of the magnet rotor of two, one magnet row each forms a north and the other magnet row a south pole on the periphery of the magnet rotor. In the case of a four-pole magnet rotor, the north and south poles are alternately located on the periphery of the magnet rotor; Always choose a number of poles that allows an alternating type of pole.

In an embodiment of the invention, it is proposed that the magnet rotor have at least two magnet pairs each formed from two adjacent rows of permanent magnets and that the angular dimension between the rows of permanent magnets, each forming a magnet pair, is smaller than the angular dimension between the magnet pairs. This takes into account the knowledge that a more or less strong magnetic ring field with a certain basic field strength, which changes according to the polarity of the permanent magnets, is formed around the magnetic rotor, from which the decisive factors for the separation between the magnetic poles If possible, use a strong magnetic pulse to raise the field line peaks radially outwards. The arrangement of diametrically opposed magnet pairs reduces the basic magnetic field strength in the ring field around the rotor and increases the peak values of the field lines, because the magnetic field lines run primarily in the area between the closely adjacent permanent magnet rows. The greater the difference in field strength between the ring field around the rotor and the field line peaks, the more favorable the farther the two magnet pairs are from one another.

It is recommended that the base body of the magnet rotor preferably have concave recesses in the area between the magnet pairs. By means of these recesses, the magnetic field lines of the magnetic rotor can be restricted even more to the area of the permanent magnet rows of each magnet pair which are close to one another and thus more sharply defined pulses can be achieved because the basic field strength in the ring field around the rotor is reduced even further.

It is proposed that one half of the magnetic rotor have more rows of permanent magnets than the other half. With such a magnetic rotor, the two halves of the magnetic rotor having a different magnetic number can be used for solid mixtures with different fractions. Such a magnetic rotor, which has a reduced number of permanent magnets, is advantageous if not so large amounts of material are obtained in different fractions, so that the performance of a wide machine could not be exhausted. In addition, this magnetic rotor can, if necessary, be converted in such a way that the second half also has permanent magnets in every row is loaded. The permanent magnets of each second row of magnets can preferably extend axially from one end face to the center of the magnet rotor, whereby according to an advantageous embodiment half of the magnet rotor with fewer rows of permanent magnets can have at least two magnet pairs each formed from two adjacent rows of permanent magnets.

According to a further embodiment, a straightening body is arranged in the area above the material discharge zone at a distance above the drum in the magnetic field of the magnetic rotor. This is preferably made of magnetically good and electrically poorly conductive material. In the present context, a straightening body, which can be, for example, a flat or curved plate, is understood to mean a body that generates the field lines generated by the magnetic rotor in the direction of its surface and attracts the field lines. The field lines can thus be concentrated in such a way that an intensive force effect of the magnetic field on the non-ferrous metals in the area of the material discharge zone is also promoted in this way. As a result of the deeper valleys or incisions between the curved field lines that are achieved, the area that builds up in the ring field around the rotor and no longer gives any effective impulses to the non-ferrous metals due to the mutual influence of the field lines, and the magnetic field also breaks in there strengthened its power. This measure means that, in particular, even smaller fractions (less than 15 mm) of the solid mixture can be influenced magnetically sufficiently and can thus be separated better.

The straightening body should advantageously be adjustable. When the straightening body is both radially adjustable and pivotable on a radius around the axis of rotation of the magnetic rotor its distance from the drum or from the magnet rotor can be adapted to the fractions contained in the solid mixture, this distance corresponding to one and a half to three times the size of the largest grain diameter of the processed material; it can also be swiveled exactly into the area of the material drop zone.

The straightening body and the magnet rotor are preferably of the same length. The force effect of the magnetic field can thus be optimized over the entire area of the material discharge zone.

It is recommended that the straightening body is cooled, for which purpose it can have cooling fins and / or cooling pipes through which oil flows, for example. Excessive heating of the straightening body due to the eddy current flow can thus be avoided.

The drive of the magnetic rotor can preferably be provided with a speed control; For example, the speed of an electric motor that drives the magnetic rotor via belts can be controlled by means of a frequency converter. Using the frequency converter, the speed can be in the range of approx. 1000 to 3600 rpm, for example. Regulated and thus a further adjustment of the frequency of the alternating magnetic field to the solid mixture to be separated can be achieved, with very different and in particular fine-grained non-ferrous metal components in the mixture require a correspondingly higher speed and thus higher frequency. It is advantageous to drive the magnet rotor within arrange the drum.

According to a preferred embodiment, a driven conveyor belt wrapping around the drum is provided with at least one transversely arranged driver. By means of the conveyor belt, the supplied solid mixture can be evened out from the feed point to the material discharge zone on the drum by reducing the layer height of the solid mixture due to a higher belt speed than the feed conveyor, for example a vibrating trough. The conveyor belt can be driven via a drum motor arranged in the feed area. The carrier has the following purpose. The ratio of the outer diameter of the magnetic rotor to the inner diameter of the drum can be chosen to be so large that the outer diameter of the magnetic rotor is considerably smaller than the inner diameter of the drum, so that any magnetic parts that may adhere to the conveyor belt automatically fall down at the lowest point of the drum because the magnetic field of the magnetic rotor is ineffective there due to the large distance. Such parts and adhering dirt components can also be removed from the lower run of the conveyor belt with the help of a scraper. However, it cannot be completely ruled out that iron particles may not be caught by an upstream Fe separation. As a result, the fine iron particles are held in the effective area of the magnetic rotor, so that the conveyor belt passes underneath without taking these particles with them. Apart from the constant friction and the increasing amount of particles accumulating at this point (threshold effect), the particles heat up so strongly after a few seconds due to the eddy current flow that this can lead to burns on the conveyor belt. This danger can be avoided by means of the one extending across the conveyor belt in the transport direction Prevent entrainment, because as soon as the entrainer reaches the area of particle accumulation, it entrains these particles and transports them out of the effective area of the magnetic rotor or out of the heating zone.

A shaft end of a drive drum of the conveyor belt can preferably be provided with a clutch disk which is coupled with a mains-independent auxiliary drive in the event of a power failure. The problem of damage caused by warming particles also occurs in the event of a power failure in the system or when the system is switched off. The metal parts then remaining in the effective range of the magnetic rotor heat up within a few seconds due to the magnetic rotor that continues to run due to its large flywheel mass and induce eddy currents in the metal parts, so that damage to both the conveyor belt, which is usually made of plastic, and the drum can be expected . Braking the magnetic rotor to an uncritical speed takes too much time because of the large moment of inertia. On the other hand, the conveyor belt can be moved further without delay, by means of the auxiliary drive which switches on without delay, ie the conveyor belt does not have to be accelerated out of rest. After a power failure, the conveyor belt is moved on until there is no more material in the area of the magnetic rotor. The auxiliary drive does not have to maintain the full conveying speed. Because of their robust and simple construction, mechanical auxiliary motors are particularly suitable as auxiliary drives, such as, for example, a spring motor put into operation by means of a previously wound spring or a motor with weight drive known from clockworks. The mechanical auxiliary motors also require almost no maintenance and are also available in winter great cold reliable. Alternatively, a compressed air drive with a stored amount of compressed air, an emergency power unit with a continuously rotating flywheel for immediate switching on, or a direct current motor with a battery drive can be used as the auxiliary motor.

According to a further embodiment, the magnetic rotor can drive the drive drum of the conveyor belt directly or indirectly as an auxiliary drive in the event of a power failure. For indirect drive, the magnet rotor can preferably be provided with a generator that drives the drive drum. In this way, the rotational energy of the magnetic rotor, which continues to run for a certain time in the event of a power failure, is used to drive the drive drum and thus to move the conveyor belt further.

A preferably shaftless mounting of the drum by means of drum inserts advantageously makes it possible for the rotor shaft to be guided through the drum and for a drum insert to engage in the drum from each side. The drum inserts which lie flush with the inner casing of the drum and which are screwed to the drum need only engage in the drum to a slight extent, so that inside the drum there is a free space which is many times larger than the engagement length and which is sufficient in any case. to record the eccentrically arranged rotor shaft with the magnet rotor.

Shaft journals of the rotor shaft can preferably be mounted in bearing brackets which have an outer flange provided with a bolt circle, rotatable adjusting flanges preferably arranged in the bearing brackets on a bolt circle corresponding to the bolt circle of the outer flange are provided with threaded holes for screws connecting the outer flange to the adjusting flange. In this way, the magnet rotor can be shifted in the perforation corresponding steps in a defined range, that is, pivoted concentrically around the axis of rotation of the drum and the effective range of the magnets can be adjusted, for example, from the vertical of the axis of rotation of the drum to approximately 75 ° in the direction of rotation of the conveyor belt . The threaded bores can namely be arranged with a certain pitch, for example with a pitch of 6 °, on the bolt circle, so that after loosening the screws firmly connecting the outer flanges of the bearing brackets with the adjusting flanges, the adjusting flanges rotatably mounted in the bearing brackets twist and set to a new pitch that determines the eccentric rotor position.

On the bearing side of the magnetic rotor facing away from the drive side, the rotor shaft end is mounted directly in a bearing which is installed in the adjusting flange arranged eccentrically in the drum. For structural reasons, however, the rotor shaft is advantageously supported on its drive-side bearing side in a bearing bracket which is arranged eccentrically in the drum and which is non-rotatably connected to the adjusting flange and serves as a supporting body for the bearing of the drum insert. By turning the adjustment flanges in relation to the outer flanges, the adjusting flange with the bearing cover on the bearing side facing away from the drive side and the screws connecting the adjustment flange on the drive side bearing side with the bearing bracket adjust the rotor shaft bearings accordingly, thus changing the eccentric position of the magnet rotor in the drum.

According to one embodiment of the invention, covers with axial collars and bearings arranged thereon can be inserted into the drum from each end face and rotated relative to the drum. If the rotor shaft is preferably mounted in the covers, whereby the drive-side shaft end can advantageously penetrate the cover, the eccentric position of the magnetic rotor and thus the effective range of the alternating magnetic field generated by the magnetic rotor can be achieved by rotating the cover. For example, threaded bores with a certain pitch can be arranged on a bolt circle of the cover, to which a corresponding bolt circle with threaded bores, e.g. in retaining rings for the drum. After loosening and removing screws screwed into the holes, the lids can then be turned to the desired pitch, taking the magnetic rotor with them.

Preferably, at least one axle end of a support axle guided through the cover and fastened to it can be stored in a bearing bracket which has a stationary outer flange provided with a bolt circle, opposite which is an adjusting flange rigidly connected to the carrier axle and provided with threaded holes on a corresponding bolt circle is. In such an embodiment, the covers are adjusted by turning the supporting axis. The end of the axle facing away from the bearing bracket can advantageously be arranged in a support, ie it does not need to be mounted in a bearing bracket with adjusting flanges with bolt circles. Bearing brackets on both sides are only necessary if only - to create space inside the drum - stub axles penetrate the covers from both sides; in this case, a bolt circle bearing bracket could be arranged for each outer end of the axle.

It is advisable to mount the rotor shaft of the magnetic rotor in supports that are attached to the support axis in the interior of the drum at a distance from the covers. Thus, on the one hand, the rotation of the magnet rotor can be achieved via the supporting axis and, on the other hand, at least on one side of the magnet rotor create enough space inside the drum that a hydraulic motor flanged to one of the supports and driving the rotor shaft can advantageously be arranged there. A motor for the rotor shaft located inside the drum means that no power transmission elements are required.

The hydraulic motor can preferably be connected via lines to supply bores on the supporting axle and can thus be supplied with hydraulic fluid by a hydraulic unit (not shown).

Fig. 1

eine Wirbelstromscheidevorrichtung mit vorgeschaltetem Materialaufgabeförderer und erfindungsgemäß einstellbarem Magnetrotor, der exzentrisch im Quadranten der Abwurfzone einer von einem Fördergurt angetriebenen Trommel gelagert ist, in schematischer Seitenansicht;

Fig. 2

den Fördergurt mit Trommel und Magnetrotor gemäß Fig. 1, in der Draufsicht;

Fig. 3

den gemäß Fig. 1 in der Trommel gelagerten Magnetrotor, in der Seitenansicht als Einzelheit vergrößert dargestellt;

Fig. 4

als Einzelheit einen zwei diametral gegenüberliegende Magnetpaare aufweisenden Magnetrotor, im Querschnitt;

Fig. 5

den Magnetrotor gemäß Fig. 4 mit konkaven Einschnitten in den Bereichen zwischen den Magnetpaaren;

Fig. 6

perspektivisch und schematisch dargestellt einen Magnetrotor, bei dem die Permanentmagnete jeder zweiten Reihe axial lediglich bis zur Mitte des Grundkörpers angeordnet sind;

Fig. 6a

die weniger Reihen Permanentmagnete aufweisende Hälfte des Magnetrotors gemäß Fig. 6, jedoch mit zwei diametral gegenüberliegenden Magnetpaaren;

Fig. 7

die Trommel mit der gemäß Fig. 1 darin exzentrisch gelagerten Magnetrotorwelle, im Längsschnitt;

Fig. 8

als Einzelheit eine Lagerkonsole mit einem angeschweißten Außenflansch, der mit einem Einstellflansch verschraubt ist, wobei beide Flansche mit gleichen Lochkreisen versehen sind, in der Vorderansicht;

Fig. 9

schematisch dargestellt einen mechanischen, federbetätigten Not-Antrieb für eine Fördergurt-Antriebstrommel der Wirbelstromscheidevorrichtung gemäß Fig. 1;

Fig. 10

eine Ausführung einer erfindungsgemäßen Wirbelstromscheidevorrichtung mit einer durch stirnseitige Deckel der Trommel hindurchgeführten Tragachse und einem auf einer zur Achse exzentrisch angeordneten Rotorwelle gelagerten Magnetrotor, im Längsschnitt; und

Fig. 11

eine unter Beibehaltung des Tragachsen-Prinzips gemäß Fig. 10 abgewandelte Ausführung einer erfindungsgemäßen Wirbelstromscheidevorrichtung, bei der der Rotorantrieb im Trommelinneren angeordnet ist.

The invention is explained in more detail below with reference to the embodiment shown in the drawing. Show it:

Fig. 1

an eddy current separation device with upstream material feed conveyor and adjustable magnetic rotor according to the invention, which is mounted eccentrically in the quadrant of the discharge zone of a drum driven by a conveyor belt, in a schematic side view;

Fig. 2

the conveyor belt with drum and magnetic rotor according to Figure 1, in plan view.

Fig. 3

the magnet rotor mounted in the drum according to FIG. 1, shown enlarged as a detail in the side view;

Fig. 4

as a detail a magnet rotor having two diametrically opposed magnet pairs, in cross section;

Fig. 5

4 with concave incisions in the areas between the magnet pairs;

Fig. 6

Perspective and schematically shown a magnetic rotor in which the permanent magnets of every second row are arranged axially only up to the center of the base body;

Fig. 6a

half of the magnet rotor according to FIG. 6, which has fewer rows of permanent magnets, but with two diametrically opposed magnet pairs;

Fig. 7

the drum with the magnet rotor shaft eccentrically mounted therein according to FIG. 1, in longitudinal section;

Fig. 8

as a detail, a front view of a bearing bracket with a welded-on outer flange, which is screwed to an adjusting flange, both flanges being provided with the same circles of holes;

Fig. 9

schematically shown a mechanical, spring-operated emergency drive for a conveyor belt drive drum of the eddy current separating device according to FIG. 1;

Fig. 10

an embodiment of an eddy current separating device according to the invention with a carrying axis passed through the front cover of the drum and a magnet rotor mounted on a rotor shaft arranged eccentrically to the axis, in longitudinal section; and

Fig. 11

an embodiment of an eddy current separating device according to the invention modified while maintaining the supporting axis principle according to FIG. 10, in which the rotor drive is arranged inside the drum.

In a system preferred in the context of the eddy current separating device according to the invention, a solid mixture containing nonferrous metals is placed on a vibrating trough 1 designed as a feed conveyor according to FIG. During transport in the direction of conveyance 2, the feed material is evened out in height and width on the vibrating trough 1, which supports the later separation of the mixture components. The vibrating trough 1 inclined in the conveying direction 2 discharges the mixture from a low height onto a conveyor belt 3. The conveyor belt 3 works in particular with a horizontal upper run (conveyor level) and loops around a drive drum 4 arranged below the discharge end of the vibrating trough 1 and a drum 5 arranged further forward in the conveying direction 2. The speed of the conveyor belt 3 is greater than the conveying speed of the vibrating trough 1, so that the layer height of the mixture is further reduced as a result of the single-layer position achieved when the material is transferred to the conveyor belt 3.

A magnet rotor 6 is arranged eccentrically in the drum 5 and has rows of permanent magnets 9 extending in the longitudinal direction of the rotor shaft 7 and fastened in the base body 8 with alternating north-south polarity. A speed-controllable drive 10, for which an electric motor is used, drives the magnet rotor 6 via a belt 11; for this purpose the belt drives a pulley 12 which is wedged on the drive side of the magnetic rotor 6 with an extended rotor shaft end 13 (cf. FIG. 7). The axis of rotation 14 of the magnet rotor 6 and thus the rotor shaft 7 or the magnet rotor 6 can be adjusted concentrically on a radius around the drum axis of rotation 15. The effective range of the permanent magnets 9 of the magnetic rotor 6 can be defined in a quadrant 18 of the discharge zone which is delimited by the vertical 16 and horizontal 17 passing through the axis of rotation 15 of the drum 5 and which defines the area in which the mixture lying on the conveyor belt 3 slips due to gravity or falling comes to be adjusted. The air gap 19 between the magnetic rotor 6 and the inner jacket of the drum 5 is also the material discharge zone 20 in this area - this is shown in FIG. 3 as the angle between the dashed and double-dotted reference lines - having the smallest area.

In the case of the magnet rotors 306 and 406 shown in FIGS. 4 and 5, the base bodies 308 and 408 are provided with two diametrically opposed magnet pairs 78, 79. The angular dimension 80 between adjacent rows of permanent magnets 9 forming a magnet pair 78 or 79 is substantially smaller than the angular dimension 81 between the two magnet pairs 78 and 79. Due to the closely spaced rows of permanent magnets 9 of the magnet pairs 78 and 79, on the one hand and, on the other hand, the magnet pairs 78 and 79, which are far apart from one another, has the effect that the magnetic field lines generated by the magnet rotor 306 and 408 are largely limited to the region of the closely spaced poles of the adjacent rows of permanent magnets 9, so that more pronounced magnetic pulses are formed. The limitation of the magnetic field lines to the region of the closely spaced poles of the two rows of permanent magnets of the magnet pairs 78 and 79 is also supported by the concave, axially continuous recesses 82 in the base body 408 according to FIG. 5.

In a further embodiment of a magnetic rotor 506, one half 506a has more rows of permanent magnets 9a, 9b than the other half 506b; 6, only every second row of the rows of permanent magnets arranged peripherally in the base body 508 with an alternating pole sequence has permanent magnets 9a extending over the entire width of the magnet rotor 506, while the other rows from an end face only axially up to that through the line 83 marked center of the magnetic rotor 506 are provided with permanent magnets 9b. As can be seen in only the right half 506b of the magnet rotor 506 according to FIG. 6, which is provided with fewer rows of permanent magnets 9a, there are two magnet pairs 78a, 79a formed from two adjacent rows of permanent magnets, which are diametrically opposed . The rows lying between the magnet pairs 78a, 79a are free of permanent magnets up to the center of the magnet rotor 506, which is identified by the line 83a. Solid magnet mixtures of different fractions can be added to the magnet rotor 506 separately onto the halves 506a or 506b lying on the left or right of the line 83 in FIG. 6 and in this way with a magnet rotor 506 two different solid mixtures are treated. For the separate feeding of the solid mixtures, the existing feed conveyor 1 or the conveyor belt 3 can be assigned a partition wall (partition plate) which extends in the middle in the conveying direction; alternatively, there may be two separate feeders.

The mixture transported by means of the conveyor belt 3 far beyond the center of the apex (see vertical 16) of the drum 5 is already in a throwing parabola 21, for which there is a most deflected force due to the force of the eddy current which is fully effective at the material discharge zone 20 Curve with a correspondingly strong repulsion of the non-ferrous metals results. The non-ferrous metals deflected according to the throwing parabola 21 fall in a defined manner into a collecting container, not shown, which is removed from the collecting point for the other mixture components. The separation into valuable non-ferrous metal components and other components is supported by means of a separating saddle 22 which can be adjusted with its apex in a substantially horizontal direction. According to arrow 23, the latter components fall downward essentially without deflection and, viewed in the direction of transport 2, reach an area in front of the separating saddle 22. A driver 24 of the conveyor belt 3 prevents material accumulations of any FE components in the effective range of the magnet rotor and a scraper 37 below of the lower strand of the conveyor belt 3 possibly finally sticks to iron particles remaining on the conveyor belt 3 as well as adhering fine dirt components due to the magnetic force.

1 and 3, the magnet rotor 6 assumes a position in which the angle between the vertical 16 passing through the drum axis of rotation 15 and a connecting line 25 '(shown in broken lines) of the drum axis of rotation 15 with the axis of rotation 14 of the rotor shaft 7 is approximately 45 ° is. The adjustment angle of the effective range of the magnetic field of the magnetic rotor 6 can - starting from the vertical 16 - be 75 ° in the direction of rotation, as defined by the angle 26 between the solid connecting line 25 and the vertical 16 in FIGS. 1 and 3; the desired position of the magnetic rotor can be varied accordingly.

The quality of the separation effect, in particular if fractions of small grain size are contained in the solid mixture supplied, is further improved by a straightening body 84 shown in FIG. 3, which is located in the area above the material discharge zone 20 at a distance above the drum 5 in the magnetic field of the magnetic rotor 6 is located and extends over the entire length of the magnetic rotor 6. The straightening body 84 namely causes the field lines of the alternating magnetic field generated by the magnetic rotor 6 to extend to the straightening body 84, which attracts the field lines and concentrates them in the desired manner. It is thus possible to form elongated field lines with deeply incised valleys which are only a short distance from the surface of the drum 5 and which provide defined impulses on the material components. An optimal force effect of the magnetic field can be achieved if the straightening body 84, which can be pivoted in the circumferential direction and / or is adjustable in its radial distance from the surface of the drum 5, assumes the position shown in FIG. 3, ie on the extension of that by the Material discharge zone 20 and the drum axis of rotation 15 extending connecting line 25 '.

As shown in FIG. 7, drum inserts 27 engage the drum 5 flush with the inner lateral surface from both sides; the drum 5 is thus shaftless. The drum inserts 27 are rotatably connected to the drum 5 by means of screws 28 and retaining rings 29 and rotate about bearings 30, of which the bearing on the drive side 31 is mounted on a bearing bracket 32 and on the opposite side on an adjusting flange 33. The bearing bracket 32 and the adjustment flange 33 accommodate rotor shaft bearings 34, in which the rotor shaft 7 rotates with shaft journals 35, 36. The bearing bracket 32 and the adjustment flange 33 on the opposite side receive the rotor shaft bearings 34 eccentrically. The bearing bracket 32 on the drive side 31 is connected by means of screws 39 to an adjusting flange 40 on the drive side 31.

Both the adjusting flange 33 and the adjusting flange 40 have threaded bores 42 arranged radially from one another on their outer circumference with a certain pitch 41 (cf. FIG. 8); these lie on a bolt circle 43, which corresponds to a bolt circle 44 for bores 45 in an outer flange 47 welded to a bearing bracket 49 both on the drive side 31 and on the opposite bearing side. As long as screws 48 screwed into the corresponding bores 42 and 45 connect the outer and adjusting flanges 47 and 33 or 40 to one another, the eccentric position of the rotor shaft 7 in the drum 5 remains unchanged. Only after loosening and removing the screws 48 and then turning the adjustment flanges 33, 40 which are connected to one another for common adjustment via a bracket 38 (adjustment positions of the bracket 38 are shown in dashed lines in FIG. 8) by one or more divisions 41 are adjusted due to the connection of the adjustment flange 40 by means of screws 39 with the bearing bracket 32 or, via the adjusting flange 33, the rotor shaft bearings 34 arranged therein.

In Fig. 8, the bearing bracket 49 of the drive side 31 is shown as a detail with the underlying and therefore not visible adjusting flange 40 screwed to the outer flange 47. The bearing brackets 49 can, for example, be screwed to the bearing arms 46 of the conveyor belt 3 anchored to the foundation by means of supports 62 (FIG. 7). To stiffen and increase the strength of the bearing of the rotor shaft 7, the bearing bracket 49 is provided with a vertical support 50 and a curved rib 51 welded on the one hand to the bracket 50 and on the other hand to the bearing bracket 49. The screws 48 which are necessarily to be loosened to adjust the axis of rotation 14 of the magnet rotor 6 concentrically to the axis of rotation 15 of the drum are all freely accessible.

So that the conveyor belt 3 does not stop immediately in the event of a power failure, but at least continues to run until the mixture lying thereon is discharged beyond the drum 5, a clutch disc 53 is arranged on a shaft end 52 of the drive drum 4, which at Power failure is coupled with an auxiliary drive 61 (see. Fig. 1). The auxiliary drive 61 shown is designed as a mechanically working spring motor and has a corresponding coupling part 54 on a shaft 55 opposite the clutch disc 53 and disengaged when the mains voltage is applied. The coupling part 54 engages with a locking finger 56 in a spring which is also mounted on the shaft 55 receiving spring housing 57 a. By rotating the spring housing 57 by means of a Motor 58, the spring is wound, ie preloaded, the number of revolutions being monitored by a revolution counter 59. A current meter 60 is connected to the motor 58, which allows a motor current measurement to be carried out to check for spring breakage or other damage when the spring is being wound or wound. If the mains voltage falls together, the clutch part 54 engages in the clutch disc 52, the locking finger 56 disengaging from the spring housing 57, so that the stored energy of the spring is released. The spring housing 57, which then rotates together with the shaft 55, transmits the rotational movement to the drive drum 4 via the electromagnetic clutch consisting of the clutch disc 53 and the clutch part 54; the conveyor belt 3 moves accordingly forward.

Alternatively, in the event of a power failure, the run-on energy of the magnet rotor 6 can be used and, for example, the drive drum 4 can be driven by a magnet rotor 6 which continues to run for a certain time, ie also without current, via a clutch. As shown schematically in FIG. 2, the wake energy of the magnetic rotor 6 feeds a generator 85 arranged on the rotor shaft, which generator is electrically connected to the drive drum 4 according to the broken line 86 and is also connected to a current source 88 via an intermediate switch 87. If the mains voltage drops to zero in the event of a power failure, a relay of the intermediate switch 87 drops out accordingly and switches the generator 85 to the power supply to the drive drum 4. Since the intermediate switch 87 is connected to the power source 88, the intermediate switch relay switches on the normal drive immediately and the generator 85 as soon as the mains voltage is present again.

In the embodiment of an eddy current separating device according to the invention shown in FIG. 10, a cover 63 with an axial collar 64 and a bearing 65 arranged thereon engages in the drum from each end face. During operation, the drum 105 rotates on the bearings 65, while the covers 63 are welded to a support shaft 66 which is guided through the drum in the longitudinal direction and remain in their position. The support axis 66, which at the same time defines the axis of rotation 115 of the drum, projects with axles 67, 68 from the covers 63 and is mounted outside of the drum 105 in a bearing bracket 146 on the one hand and in a support 69 on the other. The bearing bracket 146 receiving the axle end 67 consists of a stationary, with a bolt circle 144 is provided with an outer flange 147 which is opposite an adjustment flange 133 rigidly connected to the support shaft 66; the adjustment flange is provided on a corresponding bolt circle 143 with threaded holes 142.

The magnet rotor 106 with its axis of rotation 114 lies eccentrically in the drum 105. The shaft end of the rotor shaft 107 facing away from the drive side 131 is supported by a bearing 70 which, like the bearing 71, is arranged on the drive-side shaft end 136 in an inner bearing shoulder 72 of the cover 63 is. On the drive side 131, the rotor shaft 107 penetrates the cover 63 with the shaft end 136; A pulley 112 is arranged on the shaft end 136.

In order to adjust the position of the magnetic rotor 106 in the drum 105, after loosening and removing the screws symbolized by lines through the bores of the adjusting flange 133 and the outer flange 147, the screws are fixed with the support shaft 66 connected adjusting flange 133 rotated relative to the non-movable outer flange 147 to the new position to be determined by means of the hole division. Since the covers 63 are welded to the support shaft 66, the rotational movement of the adjusting flange 133 is transmitted to the covers 63, which thus take the rotor shaft 107 mounted in the covers and consequently the magnet rotor 106 with them.

The embodiment of an eddy current separating device according to the invention shown in FIG. 11 does not differ from the embodiment according to FIG. 10 with regard to the structure of the supporting axis and the adjustability of the magnetic rotor 206 with its axis of rotation 214. Here too, the bearing bracket 246 receiving the axis end 67 consists of a stationary, with a bolt circle 244 provided outer flange 247, which is opposite an adjusting flange 233 rigidly connected to the support shaft 66; the adjusting flange is provided on a corresponding hole circle 243 with threaded bores 242. The only difference, however, is the mounting of the rotor shaft 207 of the magnetic rotor 206 in separate supports 73, 74, which are welded in the interior of the drum at a distance from the covers 63 to the support axis 66 which simultaneously defines the drum axis of rotation 215. The support 74 is displaced inward to such an extent that there is sufficient free space for a drive flanged directly to the support 74, which is designed as a hydraulic motor 75 driving the rotor shaft 207. The hydraulic motor 75 is connected via lines 76 to supply bores 77 for the inlet and outlet of the hydraulic fluid, which lead through the support shaft 66 or the shaft end 68 thereof to a pressure medium source, not shown. When the adjusting flange 233 is rotated, the supports 73, 74 are connected to the supporting axis due to the fixed connection 66 corresponds to the rotor shaft 207 mounted in the supports 73, 74. In this embodiment of the eddy current separating device, the covers 63 do not need to be connected to the supporting axis 66, that is to say they do not have to be rotated in order to enable a new setting position of the magnetic rotor 206 in the drum 205.

Claims (36)

1. Apparatus for separating non-magnetizable metals, in particular non-ferrous metals, from a mixture of solid components, by means of a rotating drum (5) in which a rotating magnetic rotor (6) fitted with permanent magnets (9) is arranged eccentrically, characterised in that the position of the axis of rotation (14) of the magnetic rotor (6) in the quadrant (18) of the material throw-off zone (20), and thus the effective region of the alternating magnetic field produced by the magnetic rotor (6), is adjustable by radial displacement.
2. Apparatus according to claim 1, characterised in that the magnetic rotor (6) is pivotable about the axis of rotation (15) of the drum (5).
3. Apparatus according to claim 1 or claim 2, characterised in that the air gap (19) between the magnetic rotor (6) and the drum (5) is smallest in the region of the material throw-off zone (20).
4. Apparatus according to any one or more of claims 1 to 3, characterised in that the circumferential speed of the drum (5) is adjustable.
5. Apparatus according to any one or more of claims 1 to 4, characterised in that the magnetic rotor (6) has at least two rows of permanent magnets (9) arranged longitudinally of the rotor shaft (7).
6. Apparatus according to claim 5, characterised in that the magnetic rotor (306 or 406) has at least two magnet pairs (78, 79) each comprising two neighbouring rows of permanent magnets (9) and that the angle (80) between the rows of permanent magnets (9) forming a respective magnet pair (78 and 79) is smaller than the angle (81) between the magnet pairs (79, 79).
7. Apparatus according to claim 6, characterised in that the body (408) of the magnetic rotor (406) has recesses (82) in the regions between the magnet pairs (78, 79).
8. Apparatus according to claim 7, characterised in that the recesses (82) are concave.
9. Apparatus according to any one or more of claims 5 to 8, characterised in that one half (506a) of the magnetic rotor (506) has more rows of permanent magnets (9a, 9b) than the other half (506b).
10. Apparatus according to claim 9, characterised in that the permanent magnets (9b) of every second row of magnets extends axially from one end of the magnetic rotor (506) only to the middle thereof.
11. Apparatus according to any one or more of claims 5 to 9, characterised in that the half (506b) of the magnetic rotor with fewer rows of permanent magnets (9a) has at least two magnet pairs (78a, 79a), each comprising two neighbouring rows of permanent magnets (9a), which extend axially from one end of the magnetic rotor (506) to the middle (83a) thereof.
12. Apparatus according to any one or more of claims 1 to 11, characterised in that a field-directing member (84) is arranged in the region above the material throw-off zone (20) spaced above the drum (5) in the magnetic field of the magnetic rotor (6).
13. Apparatus according to claim 12, characterised in that the field-directing member (84) is adjustable.
14. Apparatus according to claim 12 or claim 13, characterised in that the field-directing member (84) consists of material of good magnetic but poor electrical conductivity.
15. Apparatus according to any one or more of claims 12 to 14, characterised in that the field-directing member (84) and the magnetic rotor (6) are the same length.
16. Apparatus according to any one or more of claims 12 to 15, characterised in that the field-directing member (84) is a rotor rotating at the speed of the conveyor belt (3).
17. Apparatus according to any one or more of claims 12 to 16, characterised in that the field-directing member (84) is cooled.
18. Apparatus according to any one or more of claims 1 to 17, characterised by a drive (10; 75) for the magnetic rotor (6) with speed control.
19. Apparatus according to any one or more of claims 1 to 18, characterised by a drive means (75) for the magnetic rotor (6) arranged within the drum (5).
20. Apparatus according to any one or more of claims 1 to 19, characterised in that a driven conveyor belt (3) passing round the drum (5) is provided with at least one transverse carrier member (24).
21. Apparatus according to any one or more of claims 1 to 20, characterised in that one shaft end (52) of a driving drum (4) for the conveyor belt (3) is provided with a coupling disc (53) arranged to be coupled to an auxiliary drive (61, 85) independent of the mains power supply in the case of mains power failure.
22. Apparatus according to any one or more of claims 1 to 21, characterised in that in the event of power failure the magnetic rotor (6) drives the driving drum (4) of the conveyor belt (3).
23. Apparatus according to claim 21 or claim 22, characterised in that the magnetic rotor (6) is provided with a generator (85) driving the driving drum (4).
24. Apparatus according to any one or more of claims 1 to 23, characterised by shaftless mounting of the drum (5) by means of drum inserts (27).
25. Apparatus according to any one or more of claims 1 to 24, characterised in that the rotor shaft (7) passes through the drum (5) and a drum insert (27) engages into the drum (5) from each end.
26. Apparatus according to any one or more of claims 1 to 25, characterised in that the shaft journals (35, 36) of the rotor shaft (7) are mounted in bearing brackets (49, 46, 32, 33) each having an outer flange (47) provided with a hole circle (44).
27. Apparatus according to claim 26, characterised by rotatable adjusting flanges (33, 40) on the bearing brackets (49) which are provided, on a hole circle (43) corresponding to the hole circle (44) of the outer flange (47), with threaded holes (42) for connecting screws (48) to connect the outer flange (47) to the respective adjusting flange (33 or 40).
28. Apparatus according to claim 26 or claim 27, characterised in that the rotor shaft (7) is mounted at its driving end (31) in a bearing carrier (32) arranged eccentrically in the drum (5), which is connected to the intermediate flange (40) as carrier for the bearing (30) of the drum insert (27).
29. Apparatus according to any one or more of claims 1 to 24, characterised in that caps (63) with axial collars (64) and bearings (65) arranged thereon engage in the drum (105, 205) from each end and are rotatable relative to the drum (105, 205).
30. Apparatus according to claim 29, characterised in that the rotor shaft (107) is mounted in the caps (63).
31. Apparatus according to claim 29 or claim 30, characterised in that the shaft end (136) of the rotor shaft (107) on the driving side passes through the cap (63).
32. Apparatus according to any one or more of claims 29 to 31, characterised in that at least one end (67) of a carrying axle (66) that passes through the cap (63) and is non-rotatably attached thereto is mounted in a bearing bracket (146, 246) which has a stationary outer flange (147, 247) that is provided with a hole circle (144, 244) and faces an adjusting flange (133, 233) that is connected rigidly to the carrying axle (66) and is provided with threaded holes (142, 242) on a corresponding hole circle (143, 243).
33. Apparatus according to any one or more of claims 29 to 32, characterised by a support (69) for the end (68) of the axle remote from the bearing brackets (146, 246).
34. Apparatus according to any one or more of claims 1 to 24 and 29, 32 or 33, characterised in that the rotor shaft (207) of the magnetic rotor (206) is mounted in supporting members (73, 74) which are attached to the carrying axle (66) in the interior of the drum and spaced from the caps (63.
35. Apparatus according to claim 34, characterised by a hydraulic motor (75), driving the rotor shaft (207), which is flange-connected to one of the supporting members (74).
36. Apparatus according to claim 35, characterised in that the hydraulic motor (75) is connected via supply lines (76) to supply passages (77) in the carrying axle (66).

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