WO1993009873A1

WO1993009873A1 - Method and device for fragment separation

Info

Publication number: WO1993009873A1
Application number: PCT/SE1992/000787
Authority: WO
Inventors: Einar Andersson
Original assignee: Almhults Elektromekaniska Einar Andersson AB
Current assignee: Almhults Elektromekaniska Einar Andersson AB
Priority date: 1991-11-18
Filing date: 1992-11-17
Publication date: 1993-05-27
Anticipated expiration: 1994-05-18
Also published as: SE9103388L; SE468342B; SE9103388D0; AU2959992A

Abstract

In the separation of fragments (7, 8) of two non-magnetic metallic materials, such as copper and lead, in a fragment mixture (4), use is made of a rotor (1) and a feeding unit (3, 5) comprising a conveying path (3) substantially perpendicular to the axis of the rotor (1). The rotor (1) comprises juxtaposed axial permanent-magnet rods (2) of alternate polarity. The fragment mixture (4) is fed in the form of a thin layer along the conveying path (3), and the rotor (1) is rotated in such a direction (P1) that it moves, at its underside, substantially in the feeding direction (P2) of the fragment mixture (4).

Description

METHOD AND DEVICE FOR FRAGMENT SEPARATION

The present invention relates to a method for sepa¬ rating fragments of a non-magnetic metallic material, such j 5 as copper, from a mixture of such fragments and fragments of at least one other non-magnetic metallic material, such as lead. The invention also concerns a device for imple¬ menting the method.

In order to recover reusable materials, electric 10 cables of all sorts are ground to fragments of different shape and appearance. One then obtains a mixture of frag¬ ments of many different materials, such as plastics, rub¬ ber, iron, aluminium, copper and lead. If these materials are to be effectively recycled, they have to be separated 15 from one another. However, efforts in this direction have not been entirely successful. Thus, there is available on the market a so-called cable granulate, which consists of copper and lead fragments that have resisted all attempts at separation. 20 One object of the present invention is, therefore, to provide a method for effectively separating the fragments of a non-magnetic metallic material, such as copper, from a mixture of such fragments and fragments of at least one other non-magnetic metallic material, such as lead. 25 According to the invention, this object is achieved by a method of the above type, which is characterised by feeding the fragment mixture in the form of a thin layer along a conveying path ending at a discharge position located at the underside of a rotor having a substantially 30 horizontal axis and comprising juxtaposed axial permanent- _j magnet rods of alternate polarity, the fragment mixture being fed in a direction substantially perpendicular to the axis of the rotor; and rotating the rotor in such a direction that it moves, at its underside, substantially 35 in the feeding direction of the fragment mixture. Another object of the invention is to provide a simple device for implementing this method.

According to the invention, this object is achieved by a device which is characterised by a rotor having a substantially horizontal axis and comprising juxtaposed axial permanent-magnet rods of alternate polarity, and a feeding unit adapted to feed the fragment mixture in the form of a thin layer along a conveying path which is sub¬ stantially perpendicular to the axis of the rotor and ends at a discharge position located at the underside of the rotor.

Preferably, the conveying path is a slide path con¬ nected to a vibrator for vibrating said path.

The invention will be described in more detail below with reference to the accompanying drawing, which is a schematic side view showing a separation device according to the invention.

The illustrated device comprises a cylindrical rotor 1 having an outer iron jacket. The rotor 1 is lying, i.e. has a horizontal axis, and is rotatable in the direction of the arrow PI by means provided therefor (not shown). Permanent-magnet rods 2 of alternate polarity (N and S), extending axially along the entire rotor 1, are, at equal intervals, glued to the jacket over its entire circum- ference (and not just over a portion thereof, as shown in the drawing for the sake of simplicity). The magnets 2 are of the type sometimes referred to as "supermagnets", and in this case are magnets marketed under the trade name "Neodymium". A conveying path 3, extending in a substantially per¬ pendicular direction to the axis of the rotor 1, conveys a fragment mixture 4 in the direction indicated by the arrow P2, from a receiving position to a discharge position. In the preferred embodiment, the conveying path 3 is a chan- nel forming a slide path slightly inclined in relation to the horizontal plane and connected to a vibrator 5 serving to vibrate the conveying path 3. A funnel-shaped supply unit 6 is provided at the receiving position for discharg¬ ing, onto the conveying path 3, a mixture 4 of fragments

7 of a non-magnetic metallic material, in this case lead, and fragments 8 of another non-magnetic metallic material, in this case copper. The fragment mixture 4 is transported in the form of a thin layer to the discharge position, which is defined by the downstream end 9 of the conveying path 3, this end being located at the underside of the rotor 1. In the illustrated embodiment, the downstream end 9 of the conveying path 3 is located straight below the axis of the rotor 1. However, the downstream end 9 of the conveying path 3 may be situated slightly to the left (with regard to the drawing) of the illustrated position. The conveying path 3 should not, however, extend beyond the lowest point of the rotor 1, i.e. the point located straight below the rotor axis.

The conveying path 3 is made of glass-fibre material, but may, of course, be made of another suitable material, such as plastics material, which is not affected by induc- tion (heated) during the rotation of the rotor 1.

A container 10 for collecting lead fragments 7 is placed below the downstream end 9 of the conveying path 3. Likewise, a container 11 for collecting copper fragments

8 is placed a distance ahead, as seen in the conveying direction P2 of the conveying path 3.

The fragment mixture 4 is fed in a thin layer on the conveying path 3 vibrated by means of the vibrator 5. During the feeding operation, many of the fragments in the mixture 4 are kept suspended in the air owing to the vibrations, which facilitates the subsequent separation. The rotor 1 is rotated at high speed (about 1, 500 rpm) in the direction indicated by the arrow PI. As is evident from the drawing, the direction of rotation PI at the underside of the rotor 1 substantially coincides with the feeding direction P2. When the fragment mixture 4 reaches the downstream end 9 of the conveying path 3, the lead fragments 7 drop into the container 10. Unlike the lead fragments 7, the copper fragments 8 are strongly affected by the magnetic field generated by the rotating rotor 1, and are flung further on in a substantially tangential direction so as to impinge upon a wall 11a of the con- tainer 11 and drop into this container 11.

It has been found that the device according to the invention yields astonishing results, in that the frag¬ ments reaching the container 11 only contain a minute amount of lead and at least 96% of copper. It goes without saying that the inventive device is not restricted to the separation of copper and lead, but may be used for separating other non-magnetic metallic materials, such as lead and aluminium. Also, the device can be used for separating several different non-magnetic metallic materials from one another, e.g. lead, copper and aluminium. In the separation, advantage is then taken of the fact that the materials are affected differently by the magnetic field generated by the rotating rotor, and are thereby flung over different distances, to be collect- ed in different containers positioned at the particular flinging distance of each material.

Claims

1. A method for separating fragments (8) of a non- magnetic metallic material, such as copper, from a mixture (4) of such fragments and fragments (7) of at least one other non-magnetic metallic material, such as lead, c h a r a c t e r i s e d by feeding the fragment mixture (4) in the form of a thin layer along a conveying path (3) ending at a discharge position (9) located at the under¬ side of a rotor (1) having a substantially horizontal axis and comprising juxtaposed axial permanent-magnet rods (2) of alternate polarity, the fragment mixture (4) being fed in a direction substantially perpendicular to the axis of the rotor; and rotating the rotor (1) in such a direction (PI) that it moves, at its underside, substantially in the feeding direction (P2) of the fragment mixture (4) .

2. A device for implementing the method of claim 1 for separating fragments (8) of a non-magnetic metallic material, such as copper, from a mixture (4) of such frag¬ ments and fragments (7) of at least one other non-magnetic metallic material, such as lead, c h a r a c t e r i s ¬ e d by a rotor (1) having a substantially horizontal axis and comprising juxtaposed axial permanent-magnet rods (2) of alternate polarity, and a feeding unit (3, 5) adapted to feed the fragment mixture (4) in the form of a thin layer along a conveying path (3) which is substantially perpendicular to the axis of the rotor (1) and ends at a discharge position (9) located at the underside of the rotor (1) .

3. The device of claim 2, c h a r a c t e r i s ¬ e d in that the conveying path (3) is a slide path con¬ nected to a vibrator (5) for vibrating said path (3) .