JP7798513B2 - magnetic separator - Google Patents

Description

The present invention relates to a magnetic separator. In particular, it relates to a suspended conveyor-type magnetic separator that is suspended above the object to be sorted, uses magnets to attract and separate magnetic materials mixed in the object, and then transports the resulting magnetic materials on a conveyor.

The separation and recovery of useful metals from materials such as industrial waste is a common practice. In particular, magnetic separators that utilize magnetic force are used to efficiently recover magnetic materials such as iron from materials. One type of magnetic separator is a suspended conveyor type, which is suspended above the materials and transports the magnetic materials attracted by the magnets on a conveyor.

A typical suspended conveyor-type magnetic separator is equipped with a conveyor belt suspended between a drive pulley and a driven pulley, and magnets placed in the internal space surrounded by the conveyor belt. The magnetic separator rotates the conveyor belt while the objects to be sorted are suspended in a position where they are within the magnetic field of the magnets. Magnetic materials such as iron mixed in with the objects to be sorted are attracted to the outer surface of the conveyor belt by the magnetic force of the magnets, and are transported by the rotation of the conveyor belt, thereby completing the sorting process.

The conveyor belts of hanging conveyor-type magnetic separators typically use flat belts. As a result, relatively small magnetic objects such as iron pieces become caught at the edge of the conveyor belt due to the force of being attracted to the magnet, and some of them move to the inner surface of the conveyor belt. Furthermore, some of the small magnetic objects that move to the inner surface of the conveyor belt can become pinned between the conveyor belt and the drive pulley or driven pulley and become stuck in the conveyor belt. If the magnetic separator is operated for an extended period of time, the number of magnetic objects stuck in the conveyor belt increases, causing damage to the conveyor belt or malfunctioning.

As a technology to prevent magnetic materials from getting caught on the inner surface of the conveyor belt of a magnetic separator, the inventor invented a conveyor belt with wavy bars on both sides of a flat belt, and disclosed this in Patent Document 1.

Patent document 2 also discloses a magnetic separator equipped with a cover that covers both the sides of the magnets and the edge of the conveyor belt of the magnetic separator.

Japanese Patent Application Laid-Open No. 2018-111053 Japanese Patent Application Laid-Open No. 2001-62335

Providing wavy crosspieces on both sides of a flat conveyor belt can reduce the chance of small magnetic objects getting caught in the conveyor belt. However, small pieces of iron can collide with the wavy crosspieces and bounce off into the belt. In the case of a suspended conveyor-type magnetic separator, it is difficult to prevent iron particles from getting mixed in with the wavy crosspieces. Also, if a large piece of iron is attracted to the wavy crosspieces, it may be damaged by the impact. Furthermore, conveyor belts with wavy crosspieces require more work to process than regular conveyor belts, and are therefore more expensive. Therefore, there is a need for a technology that can prevent magnetic objects from getting caught on the inner surface of the conveyor belt of a magnetic separator using a cheaper and simpler configuration.

Furthermore, in conventional suspended conveyor-type magnetic separators, meandering of the conveyor belt can occur for various reasons, such as uneven adsorption of magnetic materials. Therefore, there is a need for technology that can minimize meandering of the conveyor belt, prevent damage to the conveyor belt even if it does meander, and at the same time prevent small magnetic materials from becoming entangled in the conveyor belt.

The present invention was made in light of this current situation, and aims to provide technology that can prevent magnetic materials from becoming entangled on the inner surface of the conveyor belt of a magnetic separator using a cheaper and simpler configuration. Furthermore, the present invention aims to provide technology that can prevent magnetic materials from becoming entangled on the inner surface of the conveyor belt of a magnetic separator while suppressing meandering of the conveyor belt.

The present invention relates to a magnetic separator that prevents small pieces of magnetic material contained in materials to be sorted from becoming entangled in the belt. The magnetic separator of the present invention includes a ring-shaped conveyor belt that transports materials to be sorted on its outer surface, a magnet disposed inside the conveyor belt, and a cover member made of a non-magnetic material disposed between the conveyor belt and the magnet. The cover member of the magnetic separator includes a flat portion having a shape similar to the surface of the magnet facing the conveyor belt, longitudinally inclined portions provided at both ends corresponding to the longitudinal direction of the conveyor belt and inclined toward the magnet, and widthwise inclined portions provided at both ends corresponding to the width direction of the conveyor belt and inclined toward the conveyor belt , and a gap of 3 to 10 mm is provided between the inner surface of the conveyor belt and the underside of the cover member .

The conveyor belt of the magnetic separator of the present invention is stretched between a cylindrical head pulley equipped with a drive means, a tail pulley having the same shape as the head pulley, and an auxiliary pulley positioned above the head pulley and tail pulley. It is preferable that the auxiliary pulley of the magnetic separator of the present invention is crowned.

When crowning the auxiliary pulley, it is preferable that the taper width, i.e., the difference between the diameter at the center and the diameter at the end, be 1.0 mm or more and 5.0 mm or less.

The cover member of the magnetic separator of the present invention is preferably bent toward the conveyor belt so that the widthwise inclined portion is 50 mm or more in width and the height from the flat portion to the end of the widthwise inclined portion is 10 mm or more.

The cover member of the magnetic separator of the present invention is preferably bent toward the magnet so that the longitudinally inclined portion is 50 mm or longer and the height from the flat portion to the end of the longitudinally inclined portion is 10 mm or longer.

The magnetic separator of the present invention uses the widthwise inclined portion of the cover member to prevent small pieces of magnetic material in the materials being sorted from getting caught in the conveyor belt from both sides. This prevents small magnetic pieces from getting stuck in the conveyor belt, preventing deterioration of the conveyor belt and allowing it to be used for a longer period of time than conventional methods.

The magnetic separator of the present invention is equipped with an auxiliary pulley that is positioned above the head pulley and tail pulley, and the auxiliary pulley is crowned to effectively prevent the conveyor belt from meandering.

By optimizing the length and height of the widthwise inclined portion of the cover member, the magnetic separator of the present invention can prevent damage to both the belt and the cover member, even in the unlikely event that the conveyor belt snakes. The length and height of the widthwise inclined portion of the cover member of the present invention, in conjunction with the rotational movement of the conveyor belt, form an optimal angle that allows small pieces of magnetic material that have begun to enter the edge of the conveyor belt to be thrown outward.

The cover member for the magnetic separator of the present invention can be easily and inexpensively obtained by bending or injection molding a non-magnetic material, allowing the magnetic separator itself to be offered at a lower price.

FIG. 1 is a vertical cross-sectional view of a magnetic separator according to the present invention. FIG. 2 is a perspective view of a cover member of the magnetic separator of the present invention.

Below, a preferred embodiment of the magnetic separator of the present invention, which is a suspended conveyor-type magnetic separator, will be described in detail with reference to the drawings.

Figure 1 is a longitudinal cross-sectional view of a magnetic separator 1 of the present invention. The magnetic separator 1 includes a conveyor belt 2, a magnet 3, and a cover member 4. The magnetic separator 1 further includes a head pulley 5, a tail pulley 6, and an auxiliary pulley 7.

The magnetic separator 1 has a frame (not shown) equipped with a pair of support members and a suspension device. The support members are arranged parallel to each other at a distance from each other, with a head pulley 5 rotatably attached via a central shaft 8 to one end of the support members. A tail pulley 6 is similarly attached to the other end of the support members. A magnet 3 is fixed between the support members at a position approximately midway between the head pulley 5 and tail pulley 6. Furthermore, an auxiliary pulley 7 is rotatably attached above the head pulley 5 and tail pulley 6.

The magnetic separator 1 can be suspended above the objects to be sorted using the frame's hanging fixtures. The position of the magnetic separator 1 can be changed in various ways to suit the position of the objects to be sorted, as long as the magnetic force of the magnet reaches the objects. For example, if the objects to be sorted are transported by an inclined conveyor, the magnetic separator 1 can be placed above the objects to be sorted in an inclined position, parallel to the path along which the objects are transported.

The conveyor belt 2 is formed into a ring shape using a non-magnetic material of uniform thickness. Suitable materials for the conveyor belt 2 are rubber or resin. The conveyor belt 2 is stretched between a head pulley 5, a tail pulley 6, and an auxiliary pulley 7. When the head pulley 5 is driven by a driving means such as a motor, the conveyor belt rotates between the head pulley 5, the tail pulley 6, and the auxiliary pulley 7.

A roughly rectangular parallelepiped magnet 3 is placed inside the conveyor belt 2. The width of the magnet 3 is equal to or smaller than the width of the conveyor belt 2. A permanent magnet or an electromagnet can be used as the magnet 3. A particularly suitable material for the magnet 3 is a ferrite magnet. The magnetic force of the magnet 3 attracts the magnetic objects to be sorted to the outer surface of the conveyor belt 2, and they are carried away as the conveyor belt 2 rotates.

The cover member 4 is a plate-shaped member made of a non-magnetic material and placed between the conveyor belt 2 and the magnet 3 so as to cover the underside of the magnet 3. The preferred material for the cover member 4 is stainless steel, which has excellent durability, but wood, hard resin, etc. can also be used. The cover member 4 is attached to the magnet 3 using a fixing means such as a bolt. The cover member 4 can be attached to the magnet 3 by drilling bolt holes in the magnet 3 and fixing the cover member 4, or by fixing the cover member 4 to the magnet 3 via a fixture.

The shape of the cover member 4 will be described in more detail. Figure 2 is a perspective view of the cover member 4. The cover member 4 has a roughly rectangular flat portion 41 that is roughly equivalent to the surface of the magnet 3 facing the conveyor belt 2. The cover member 4 also has a longitudinally inclined portion 43 and a widthwise inclined portion 42.

Note that the "longitudinal direction" here refers to the length direction of the conveyor belt 2, i.e., the direction in which the conveyor belt 2 moves during operation. The longitudinal inclined portions 43 are rectangular inclined portions that are located outside a pair of the four sides of the flat portion 41 of the cover member 4 that are located on the longitudinal side, and have the same width as the flat portion 41. Additionally, the "width direction" here refers to the width direction of the conveyor belt 2, i.e., the direction perpendicular to the longitudinal direction of the conveyor belt 2. The width inclined portions 42 are rectangular inclined portions that are located outside a pair of the four sides of the flat portion 41 of the cover member 4 that are located on the width side, and have the same length as the flat portion 41.

In this embodiment, the underside of the flat portion 41 of the cover member 4, i.e., the surface not in contact with the magnet 3, is positioned on the same plane as the lower end of the head pulley 5 and the lower end of the tail pulley 6. During operation, the inner surface of the conveyor belt 2 moves with a small gap of 3 mm to 10 mm between it and the underside of the cover member 4.

Specifically, the width of the flat portion 41 of the cover member 4 is approximately the same as that of the magnet 3, and is smaller than the width of the conveyor belt 2. As a result, both ends of the conveyor belt 2 move outside the flat portion 41 or the widthwise inclined portion 42, with a small gap between them.

The longitudinally inclined portion 43 of the cover member 4 is preferably bent toward the conveyor belt so that its length from the end of the flat portion 41 is 50 mm or more, and its height from the flat portion 41 to the end of the longitudinally inclined portion 43 is 10 mm or more. The width and height of this longitudinally inclined portion 43 prevent the periphery of the cover member 4 from contacting the conveyor belt 2.

The widthwise inclined portion 42 of the cover member 4 is preferably bent toward the conveyor belt 2 so that its width from the end of the flat portion 41 is 50 mm or more and its height from the flat portion 41 to the end of the widthwise inclined portion 42 is 10 mm or more. By being bent toward the conveyor belt 2, the width and height of the widthwise inclined portion 42 are optimized to minimize the gap between the conveyor belt 2 and the cover member 4, preventing small pieces of magnetic material from getting inside the conveyor belt 2, while also preventing contact between the cover member 4 and the conveyor belt 2 even if the conveyor belt 2 meanders.

In other words, in this embodiment, the height of the widthwise inclined portion 42 needs only to be 10 mm or more, and it can be made even higher. However, if the ratio of height to width is set to 1/2 or more, in other words, if the angle of the widthwise inclined portion 42 relative to the flat portion 41 is set to 45 degrees or more, when the conveyor belt 2 meanders, the end of the conveyor belt 2 may come into contact with the cover member, causing the widthwise inclined portion 42 to be cut. For this reason, it is preferable that the angle of the widthwise inclined portion 42 relative to the flat portion 41 be less than 45 degrees.

The auxiliary pulley 7 of the magnetic separator 1 in this embodiment is crowned, with the diameter at both ends being smaller than the diameter at the center. Only the auxiliary pulley 7 is crowned; the head pulley 5 and tail pulley 6 are cylindrical. By crowning the auxiliary pulley 7, it is possible to significantly reduce the meandering of the conveyor belt 2 when it is operating under tension.

During rotation, the conveyor belt 2 has its own weight and stretches, so even when tension is applied by the central portion of the auxiliary pulley 7, a gap is created between the cover member 4. Furthermore, at the widthwise ends of the conveyor belt 2, "play" occurs corresponding to the tapered width of the crown processing of the auxiliary pulley 7. As a result, while there is almost no space between the flat portion 41 at the center of the conveyor belt 2, there is a wider space between the flat portion 41 and the widthwise ends of the flat portion 41. However, the width of the conveyor belt 2 is wider than the width of the flat portion 41, and as a result, both ends of the conveyor belt 2 are located outside the inclined widthwise inclined portion 42, so there is almost no space between the cover member 4 and the ends of the conveyor belt 2.

In this embodiment, the tapered width of the crown processing of the auxiliary pulley 7 is optimized to significantly reduce meandering of the conveyor belt 2. The most suitable range for the tapered width of the crown processing of the auxiliary pulley 7 is 1.0 mm or more and 5.0 mm or less. If the tapered width of the crown processing is too large, the gap on both sides of the belt will be too large.

The following examples further embody the present invention. Note that the dimensions and angles listed below are examples and are not intended to limit the scope of the claims.

The magnetic separator 1 in this embodiment is equipped with a 600 mm wide conveyor belt 2 and a 700 mm long, 500 mm wide ferrite magnet 3. The distance between the rotation axes of the head pulley 5 and tail pulley 6 is 1900 mm.

The cover member 4 is a plate made of stainless steel. The flat portion 41 has dimensions of 700 mm in length and 500 mm in width. The longitudinally inclined portion 43 has dimensions of 80 mm in length in the longitudinal direction (the direction of movement of the conveyor belt), 500 mm in width, the same as the flat portion 41, and a height of 20 mm from the flat portion 41. The widthwise inclined portion 42 has a longitudinal length of 700 mm, a width of 100 mm, and a height of 15 mm from the flat portion 41.

The auxiliary pulley 7 has a taper width of 2 mm.

The magnetic separator 1 of this example was placed approximately 300 mm above the objects to be sorted and operated. As a result, very few small pieces of magnetic material were caught inside the conveyor belt 2, and no meandering of the conveyor belt 2 was observed.

Specific examples of the present invention have been described in detail above based on the embodiments, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and variations of the specific examples given above. The dimensions and arrangement of each part can be freely changed to accommodate the transport form, size, and physical properties of the items to be sorted, as long as the original function is not impaired.

REFERENCE SIGNS LIST 1 Magnetic separator 2 Conveyor belt 3 Magnet 4 Cover member 5 Head pulley 6 Tail pulley 7 Auxiliary pulley 41 Flat portion 42 Width direction inclined portion 43 Longitudinal direction inclined portion 8 Rotation shaft

Claims (4)

A magnetic separator that prevents small pieces of magnetic material in the object to be sorted from getting caught in the belt,
a conveyor belt formed in a ring shape and transporting the objects to be sorted on its outer surface;
a magnet disposed inside the conveyor belt;
a cover member made of a non-magnetic material and disposed between the conveyor belt and the magnet;
It is equipped with
The cover member is
a flat portion having a shape similar to that of the surface of the magnet facing the conveyor belt;
longitudinally inclined portions provided at both ends of the conveyor belt corresponding to the longitudinal direction and inclined toward the magnet;
width direction inclined portions provided at both ends corresponding to the width direction of the conveyor belt and inclined toward the conveyor belt;
It is equipped with
A gap of 3 to 10 mm is provided between the inner surface of the conveyor belt and the lower surface of the cover member,
A magnetic separator characterized in that the widthwise inclined portion of the cover member has a width of 50 mm or more and is bent toward the conveyor belt so that the height from the flat portion to the end of the widthwise inclined portion is 10 mm or more . the conveyor belt is stretched between a cylindrical head pulley equipped with a driving means, a tail pulley having the same shape as the head pulley, and an auxiliary pulley arranged above the head pulley and the tail pulley,
2. The magnetic separator according to claim 1, wherein the auxiliary pulley is crowned. The magnetic separator described in claim 2, characterized in that the auxiliary pulley is crowned with a taper width of 1.0 mm or more and 5.0 mm or less. 4. The magnetic separator according to claim 1, wherein the longitudinally inclined portion of the cover member is bent toward the magnet so that the length of the longitudinally inclined portion is 50 mm or more and the height from the flat portion to the end of the longitudinally inclined portion is 10 mm or more.