JP7821568B2 - Magnetic separation device and magnetic separation method - Google Patents

Description

The present invention relates to a magnetic separation device and a magnetic separation method.

During various manufacturing processes, powder-like mixtures containing magnetic and non-magnetic materials are often generated. Magnetic separators are used to separate these mixtures into magnetic and non-magnetic materials.

There are many cases where large amounts of mixtures are processed, such as when breaking down molds after sand casting in foundries, when removing molding sand from removed castings by shot blasting, and when recycling slag generated at steel mills. For example, Patent Document 1 discloses the removal of molding sand by shot blasting. Patent Document 1 discloses a device that separates a mixture of shot material and sand into shot material (magnetic material) and sand (non-magnetic material). This device rotates a cylinder with a magnet inside, and the shot material is attracted to the magnet by passing over the surface of the cylinder.

Japanese Unexamined Patent Publication No. 48-72791

In the magnetic separator configuration disclosed in Patent Document 1, the shot material and sand, etc. fall in the same direction while being separated, which can result in sand, etc., being caught on the surface of the rotating cylinder along with the shot material, resulting in insufficient removal of the sand, etc.

The present invention was made in consideration of the above-mentioned circumstances, and the problem that the present invention aims to solve is to provide a magnetic separation device and magnetic separation method that can separate magnetic materials and non-magnetic materials accurately and efficiently with a simple structure.

In order to solve the above problems, the present invention employs the following means.
That is, the present invention provides a magnetic separator that separates and separates a powdery or granular mixture containing magnetic and non-magnetic materials into the magnetic and non-magnetic materials. The magnetic separator includes a powdery or granular mixture supply unit, a rotating drum, a first magnet, a natural fall region, and a conveying and falling region. The powdery or granular mixture supply unit supplies the powdery or granular mixture and allows it to naturally fall. The rotating drum has a portion of its outer surface positioned in the path along which the powdery or granular mixture naturally falls, and is driven to rotate in a direction opposite to the direction along which the powdery or granular mixture falls. The first magnet is supported inside the rotating drum and applies magnetic attraction to a certain region in the reverse direction starting from the sorting region, which is the position where the path along which the powdery or granular mixture naturally falls and the outer surface of the rotating drum come into contact. The natural fall region is a region where the powdery or granular mixture that comes into contact with the rotating drum naturally falls. The conveying and falling region is a region where the powdery or granular mixture is magnetically attracted to the rotating drum, transported, and naturally falls.
With this configuration, the rotation direction of the rotary drum is opposite to the falling direction of the powdery or granular mixture, so that the magnetic material magnetically attracted to the rotary drum can be prevented from entraining the non-magnetic material.

In one aspect of the present invention, the first magnet is arranged to impart a magnetic attraction force to the outer surface of the rotating drum, the end point of which is the vertically lower part of the rotating drum, and the powdery or granular mixture that is magnetically attracted to the first magnet and transported is sorted and allowed to fall naturally into a side lower area of the transport and fall area of the rotating drum and a vertically lower area of the transport and fall area.
According to this configuration, the powdery and granular mixture that is magnetically attracted to the first magnet and conveyed is further sorted, so that magnetic materials and non-magnetic materials can be separated with higher accuracy.

In one aspect of the present invention, a guide plate is provided at a position on the drop path facing the outer surface of the rotary drum.
According to this configuration, the magnetic material that collides with the rotary drum and is thrown off is bounced back onto the rotary drum by the guide plate, thereby improving the efficiency of recovering the magnetic material.

In one aspect of the present invention, a transport mechanism having a function of further separating magnetic materials from non-magnetic materials is disposed in at least one of the gravity drop area and the transport drop area.
According to this configuration, the powdery and granular mixture that has been magnetically separated by the rotating drum is further separated by the conveying mechanism, so that magnetic materials and non-magnetic materials can be separated with even greater precision.

In one aspect of the present invention, the conveying mechanism includes a drive mechanism including a pair of pulleys in the natural drop area and the conveying drop area, and an endless belt wound around the pair of pulleys, and a second magnet is arranged inside one of the pulleys to impart a magnetic attraction force to the outer surface of the pulley.
According to this configuration, the powdery or granular mixture that has been magnetically separated by the rotary drum is further magnetically separated by the conveying mechanism, so that magnetic materials and non-magnetic materials can be separated with even greater precision.

In one aspect of the present invention, an air separator is provided that separates the powdery or granular mixture that has fallen naturally into a region vertically below the conveying and falling region into magnetic materials and non-magnetic materials by air force.
According to this configuration, the powdery and granular mixture that has been magnetically separated is further subjected to air separation, thereby improving the accuracy of separating magnetic materials from non-magnetic materials.

In one embodiment of the present invention, the powdery and granular mixture is a shot material and molding sand generated by removing molding sand adhering to a casting after casting by shot blasting.
With this configuration, the magnetic separator of the present invention can be efficiently applied to removing foundry sand, which is a foreign substance.

The magnetic separation method of the present invention comprises the steps of:
Allowing the powdery granular mixture to fall naturally;
a rotating drum having a part of its outer surface positioned in a path along which the powdery or granular mixture falls naturally, and rotating the drum in a direction opposite to the falling direction of the powdery or granular mixture;
Applying magnetic attraction force to a certain area in the reverse direction starting from the sorting area where the powdery mixture naturally falls and the outer surface of the rotating drum come into contact;
The method includes separating and sorting the powdery or granular mixture into a free-falling region where the powdery or granular mixture falls naturally and a conveying and falling region where the powdery or granular mixture is magnetically attracted to a rotating drum, conveyed, and falls naturally.
According to this method, the rotation direction of the rotating drum is opposite to the falling direction of the powdery mixture, which prevents the magnetic material magnetically attracted to the rotating drum from engulfing the non-magnetic material, thereby enabling precise removal of foreign matter.

In one aspect of the present invention,
Applying magnetic attraction to the outer surface of the rotating drum, the end point of which is the vertical lower part of the fixed area;
The powdery or granular mixture, which is magnetically attracted to and transported by the rotating drum, is allowed to fall naturally into a side lower region of the transport and drop region below the side portion of the rotating drum and into a vertically lower region of the transport and drop region below the adjacent vertical lower portion of the rotating drum, and is then sorted.
According to this method, the powdery mixture that is magnetically attracted to the rotating drum and conveyed is further sorted, so that magnetic materials and non-magnetic materials can be separated with high precision.

In one embodiment of the present invention, the powdery and granular mixture is a shot material and molding sand generated by removing molding sand adhering to a casting after casting by shot blasting.
As described above, the magnetic separation device and magnetic separation method of the present invention can be suitably applied to the removal of foundry sand, which is a foreign substance.

The present invention provides a magnetic separation device and magnetic separation method that can separate magnetic materials from non-magnetic materials accurately and efficiently with a simple structure.

1 is a schematic cross-sectional view showing the configuration of a magnetic separator according to an embodiment of the present invention. 1 is a schematic cross-sectional view showing the configuration of a magnetic separator according to an embodiment of the present invention. 1 is a schematic cross-sectional view showing the configuration of a shot processing apparatus equipped with a magnetic separator according to an embodiment of the present invention. 1 is a schematic side view showing the configuration of a magnetic separator according to an embodiment of the present invention. FIG. 5 is an enlarged view taken along the line AA in FIG. 4. FIG. 10 is a schematic diagram showing the configuration of a magnetic separator according to a modified example of an embodiment of the present invention.

(First embodiment)
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will now be described with reference to the accompanying drawings. Fig. 1 is a schematic cross-sectional view of a magnetic separator 1 according to an embodiment of the present invention. This embodiment describes the basic configuration of the present invention.
As shown in FIG. 1, the magnetic separator 1 includes a powder mixture supply unit 2 (hereinafter referred to as the supply unit 2), a rotating drum 3, a first magnet 4, a guide plate 5, and a partition plate 6.

The supply unit 2 supplies a powdered and granular mixture 7 containing shot material 71, which is a magnetic material, and foreign matter 72, which is a non-magnetic material. In this embodiment, the foreign matter 72 is foundry sand that adheres to the casting product after casting. Therefore, the powdered and granular mixture 7 in this embodiment is the shot material 71 and foundry sand (foreign matter) 72 generated by removing the foundry sand that adheres to the casting product after casting using shot blasting. The supply unit 2 includes an inclined plate 21 and an adjustment gate 22, which includes an adjustment screw 23 and an adjustment plate 24. By turning the adjustment screw 23, the adjustment plate 24 of the adjustment gate 22 can be moved left and right on the page in FIG. 1, thereby appropriately setting the opening of the gap S and adjusting the supply amount of the magnetically attractable shot material 71 and the powdered and granular mixture 7 containing foreign matter 72 supplied from the supply unit 2. Hereinafter, the shot material 71 will be represented by an outline arrow 71, indicating the direction of flow, and the foreign matter 72 will be represented by a diagonal arrow.

The rotating drum 3 is positioned with a portion of its outer surface 31 within the fall path 8 of the powdered and granular mixture 7 (71, 72) as it falls naturally. The rotating drum 3 is driven to rotate in the direction opposite to the fall direction of the powdered and granular mixture 7 (arrow R). The first magnet 4 is supported inside the rotating drum 3 and is positioned to apply magnetic attraction to a certain area around the fall path 8 on the outer surface 31 in the reverse direction R, starting from the fall path 8. The partition plate 6 is positioned between the natural fall region P, where the powdered and granular mixture 7 is supplied and falls naturally, and the transport fall region Q, where the powdered and granular mixture 7 is magnetically attracted to the rotating drum 3 and transported, and then falls naturally. The guide plate 5 is positioned opposite the outer surface 31 of the rotating drum in the fall path 8.

Next, the operation of the magnetic separator in this embodiment will be described. When the magnetic separator 1 starts, the rotating drum 3 rotates in the direction opposite to the falling direction of the powdery/granular mixture 7 (arrow R). While the rotating drum 3 is rotating, the powdery/granular mixture 7 containing shot material 71 and foreign matter 72 is supplied to the supply section 2. The powdery/granular mixture 7 slides down the inclined plate 21, the supply amount is adjusted by the opening of the gap S, and it is supplied to the sorting area G, indicated by the dashed line, which comes into contact with the rotating drum 3.

In the sorting area G, foreign matter 72, which is non-magnetic material such as foundry sand, naturally falls into the natural fall area P below, flows along the slope 61 of the partition plate 6, and is collected. Magnetic material such as shot material 71 is magnetically attracted to the rotating drum 3, whose outer surface 31 is magnetically attracted by the first magnet 4. The magnetically attracted shot material 71 is transported by the rotating drum 3 in the direction of arrow R. After being transported to part 32 of the rotating drum 3, which is the limit of the first magnet 4's ability to apply sufficient magnetic attraction, the shot material 71 separates from the outer surface 31 of the rotating drum 3 and naturally falls into the transport and fall area Q, where it is collected as shot material 71.

In this embodiment, the powdered/granular mixture 7 is supplied by gravity and comes into contact with the outer surface 31, which has been given a magnetic attraction force, in the sorting area G, where it is magnetically separated into shot material 71 and foreign matter 72. Therefore, magnetic separation is performed immediately without restricting the path of the powdered/granular mixture 7 in the sorting area G, increasing the processing volume per unit time and improving processing efficiency. Furthermore, since magnetic separation is performed using only one rotating drum, the device configuration can be simplified.

In addition, in this embodiment, the rotating drum 3 is rotated in the sorting area G in the direction opposite to the direction of natural falling of the powdered and granular mixture 7 (arrow R). When the shot material 71 is magnetically attracted to the outer surface 31 of the rotating drum 3, foreign matter 72 may be captured by the shot material 71 and remain on the outer surface 31 of the rotating drum 3. Even in this situation, the forces acting as motion on the shot material 71 and the foreign matter 72 are opposite in direction. That is, the direction of the force acting on the shot material 71 transported by the rotating drum 3 is opposite to that acting on the foreign matter 72 that naturally falls due to gravity. This allows the foreign matter 72 to fall through the gaps between the magnetically attracted shot material 71. Furthermore, upon contact with the outer surface 31 of the rotating drum 3, which is magnetically attracted, the shot material 71 is magnetically attracted and transported in the direction opposite to gravity. In other words, since the shot material 71 leaves the sorting area G immediately after being magnetically attracted and is transported, the shot material 71 is prevented from being caught in the free-falling foreign matter 72. Therefore, the accuracy of separating the shot material 71 from the foreign matter 72 can be improved compared to when the rotating drum 3 rotates in the same direction as gravity.

Furthermore, a guide plate 5 is provided in the falling path 8 at a position facing the outer surface 31 of the rotating drum 3. This allows shot material 71 that collides with and is thrown off the outer surface 31 of the rotating drum 3 to be bounced back by the guide plate 5 and returned to the outer surface 31 of the rotating drum 3. As a result, the thrown off shot material 71 can be magnetically attracted to the rotating drum 3, improving the efficiency of shot material recovery.

Second Embodiment
Next, a second embodiment of the present invention will be described with reference to Figures 2 and 3. Figure 2 is a schematic cross-sectional view of a magnetic separator 10 according to this embodiment. The magnetic separator 10 of this embodiment differs from the first embodiment in that the range of magnetic attraction force imparted to the outer surface 31 of the rotating drum 3 by the first magnet 40 is different, and a partition plate 65 is provided in addition to the partition plate 6. Other components that are the same as those of the first embodiment are designated by the same reference numerals, and descriptions thereof will be omitted.

In this embodiment, the first magnet 40 is fixed inside the rotating drum 3 so that the end point of the area in which it exerts a magnetic attraction force on the outer surface 31 of the rotating drum 3 is the vertical lower part 33 of the rotating drum 3. Furthermore, in addition to the partition plate 6, a partition plate 65 is provided in the transport fall area Q. The partition plate 65 is disposed between the side lower area Q1 of the transport fall area Q below the side portion of the rotating drum 3 and the adjacent vertical lower area Q2 of the transport fall area Q below the vertical lower part of the rotating drum 3.

Figure 3 is a schematic cross-sectional view showing the configuration of a shot processing device 100 equipped with a magnetic separator 10 according to this embodiment. The shot processing device 100 includes a separator section 110 that separates shot material 71 from foreign matter 72, a shot processing section 120 that processes the workpiece W, and a circulation section 130 that circulates and reuses the shot material 71 within the shot processing device.

The separator section 110 includes the magnetic separator 10 and the air separator 11 described above. The air separator 11 includes a storage section 12 with an adjustment gate 13, a first air separator 14, a second air separator 15, and a third air separator 16. For the air separator 11, the flow of air for air separator is indicated schematically by arrow K. The shot processing section 120 is structured so that a projector 122 is located above a projection chamber 121. The circulation section 130 includes a screw conveyor 131 and a bucket elevator 132 equipped with multiple buckets 133.

When the shot processing device 100 is started, the projector 122 projects shot material 71 toward the workpiece W placed in the projection chamber 121, performing shot processing on the workpiece W. The projected shot material 71, along with foreign matter 72 including scale, burrs, and dust generated by the shot processing, fall to the bottom of the projection chamber 121.

A screw conveyor 131 is located below the blasting chamber 121 and transports the powdery/granular mixture 7 containing the dropped shot material 71 and foreign matter 72 to a bucket elevator 132. The bucket elevator 132 scoops up the powdery/granular mixture 7 transported by the screw conveyor 131 and transports it to the top of the device. The powdery/granular mixture 7 transported to the top of the device is dumped into a chute (not shown) at the top of the bucket elevator 132 and supplied to the separator section 110.

The separator section 110 separates the shot material 71 from the foreign matter 72 through the operation of the separator section 110, which will be described in detail later. The separated shot material 71 is supplied again to the projector 122 via hose 94, and the shot processing continues. The non-ferrous foreign matter 72 is collected via hoses 91, 92, and 95 and reused or disposed of. Shot material 71 and other ferrous materials, such as burrs and broken shot material 73, which are smaller in mass than the shot material 71 but are the same ferrous material, are collected via hose 93 and reused or disposed of as materials.

Next, the operation of the magnetic separator 10 in the separator section 110 will be described. As shown in Figure 2, the operation of the sorting area G is configured in the same way as in the first embodiment, so a description will be omitted here. The difference between the operation of the first embodiment and this embodiment is that in addition to sorting area G, there is also sorting area H. After primary magnetic sorting is performed in sorting area G, the powdered and granular mixture 7, which includes shot material 71 magnetically attracted to the outer surface 3 of the rotating drum 3 and non-ferrous foreign matter 72 embraced by the shot material 71, is transported in the direction of arrow R to sorting area H.

Of the transported powdered and granular mixture 7, non-ferrous foreign matter 72 that is not magnetically attracted separates from the side portion 34 of the rotating drum 3, the outer surface 31 of the rotating drum 3, and naturally falls into the side lower region Q1 of the transport and fall region Q. After being transported to portion 33 of the rotating drum 3, which is the limit point at which the first magnet 40 can exert sufficient magnetic attraction force, the shot material 71 separates from the outer surface 31 of the rotating drum 3, and naturally falls into the vertically lower region Q2 of the transport and fall region Q, where it is recovered as shot material 71. In this way, the second magnetic separation takes place in the sorting region H.

As shown in FIG. 3, area P of the magnetic separator 10 is connected to a hose 95, and foreign matter 72 that has naturally fallen into area P due to the primary magnetic separation is collected via the hose 95. Area Q1 is connected to a hose 91, and foreign matter 72 that has naturally fallen into area Q1 due to the secondary magnetic separation is collected via the hose 91. Similarly, shot material 71 that has naturally fallen into area Q2 due to the secondary magnetic separation is supplied to the storage section 12 of the air separator 11, which is located below the magnetic separator 10.

The amount of shot material 71 supplied to the storage section 12 is adjusted by the adjustment gate 13, and the shot material falls into the lower space, which is divided into the first to third air sorting sections 14, 15, and 16. The falling shot material 71 falls into the first to third air sorting sections 14, 15, and 16 in descending order of mass due to the wind pressure of wind K, and is sorted there. The first to third air sorting sections 14, 15, and 16 are connected to hoses 94, 93, and 92, respectively. The shot material 71 that falls into the first air sorting section 14 is supplied to the projector 122 via hose 94. Broken shot material, etc. 73 that falls into the second air sorting section 15 and foreign matter 72 that falls into the third air sorting section are collected via hoses 93 and 92, respectively.

As described above, the magnetic separator 10 of this embodiment provides the same effects as the first embodiment. In addition, by performing primary and secondary magnetic separation in the separation regions G and H, the accuracy of separation between the shot material 71 and the foreign matter 72 can be improved. Furthermore, in the secondary magnetic separation performed after the primary magnetic separation, the thickness of the powdered/granular mixture 7 adhering to the outer surface 31 of the rotating drum 3 is thin, improving the accuracy of the magnetic separation, thereby improving the overall separation accuracy. Because the primary and secondary magnetic separation are performed using a single rotating drum, the separation accuracy can be improved with a simple structure without increasing the device size. Furthermore, the simple structure consisting of only a single rotating drum reduces breakdowns and the effort required for daily maintenance. Because sufficient separation is performed through the primary and secondary magnetic separation, the air volume in the final air separation can be reduced, thereby reducing power consumption. Furthermore, because the separation accuracy throughout the entire device has been improved, it is possible to reduce the contamination of foreign matter 72 with the shot material 71 returned from the circulation section 130 to the projector 122, thereby reducing wear on the device's consumable parts and extending the device's lifespan.

(Third embodiment)
Next, a third embodiment of the present invention will be described with reference to FIGS. 4 and 5. FIG. 4 is a schematic side view showing the configuration of a magnetic separator 50 according to this embodiment, and FIG. 5 is an enlarged view taken along the line A-A in FIG. 4, corresponding to FIG. 1 of the first embodiment and FIG. 2 of the second embodiment. The magnetic separator 50 according to this embodiment differs from the magnetic separator 10 according to the second embodiment in that it includes a conveying mechanism (belt conveyor) 51 in the natural drop region P and the lower side region Q1 of the conveying drop region Q. The conveying mechanism 51 according to this embodiment has a magnetic separation function. The belt conveyor 51 includes a drive mechanism 500 including a pair of pulleys 53 and 54 and an endless belt 52 wound around the pair of pulleys 53 and 54. A second magnet 55 is disposed inside one of the pulleys 53 and 54, 53, to apply a magnetic attraction force to the outer surface of the pulley 53. Other components identical to those of the second embodiment are designated by the same reference numerals, and their description will be omitted.

When the magnetic separator 50 is started, the foreign matter 72 sorted by the action of the first magnet 40 falls naturally into the natural fall area P and the lower side area Q1 of the transport and fall area Q, using the same operation as in the second embodiment. The naturally falling foreign matter 72 includes small amounts of shot material 71 that could not be successfully magnetically separated, and broken shot material 73 made of iron. This powdered and granular mixture 7 falls onto the endless belts 52 of the horizontally arranged belt conveyors 51, 51 in the natural fall area P and the lower side area Q1 of the transport and fall area Q.

In this embodiment, the belt conveyor 51 drives the endless belt 52 in the direction indicated by arrow S in Figure 4. As described above, the belt conveyor 51 has a pair of pulleys 53, 54, one of which, the pulley 53, has a magnet 55. Therefore, foreign matter 72 in the conveyed powdered/granular mixture 7 is not magnetically attracted to the magnet 55 and falls naturally into region U. Iron-based shot material 71 and broken shot material, etc. 73 are magnetically attracted to the magnet 55 and do not fall into region U. Instead, they move downward from the left side of the pulley 53, are transported to an area beyond the reach of the magnetic attraction force of the magnet 55, and then fall naturally into region V. Therefore, the belt conveyor 51 separates the powdered/granular mixture 7 into foreign matter 72, shot material 71, and broken shot material, etc. 73 between regions U and V (third magnetic separation).

In addition to the same effects as the second embodiment, the magnetic separator 50 of this embodiment performs tertiary magnetic separation using horizontally positioned belt conveyors 51, 51 in the natural drop area P and the lower side area Q1 of the transport drop area Q, thereby further improving separation accuracy. Furthermore, because the belt conveyor 51 is positioned horizontally, the height of the magnetic separator 50 does not need to be increased, and even when the belt conveyor 51 is added, the magnetic separator 50 can be realized without increasing its size. Furthermore, because the belt conveyor 51 can operate while positioned horizontally, it can be easily implemented.

(Modification)
Fig. 6 is a diagram for explaining a modification of the above-described embodiment, and corresponds to Fig. 2 of the second embodiment. As shown in Fig. 6, the inclination angle of the inclined plate 21 of the supply unit 2 of the magnetic separator 10, the supply position of the powdery mixture 7, the rotation speed of the rotating drum 3, and the range on the outer surface 31 of the rotating drum 3 to which the magnetic attraction force is applied by the first magnet 40 can be changed as appropriate depending on the implementation situation.
For example, by changing the angle of the inclined plate 21, it is possible to change the flow rate of the powdery/granular mixture 7 supplied to the rotating drum 3. The separation accuracy can be adjusted by changing the rotation speed of the rotating drum 3. Alternatively, although a magnetic attraction force is applied to the outer surface 31 of the rotating drum 3 in the range from point 41 to 42 in FIG. 6, this range may be changed as indicated by arrows W and X. Each parameter may be adjusted to be optimal while taking into consideration the throughput and separation accuracy of the magnetic separation.

In the above embodiment, the projector 122 is described as the shot processing device, but the present invention is not limited to this and can also be applied to an injection device. In other words, the present invention can be applied in all cases where a powdery mixture containing magnetic and non-magnetic materials is to be separated.
In the above embodiment, the conveying mechanism is a belt conveyor having a magnetic sorting function, but the present invention is not limited to this, and any conveying mechanism may be used as long as it has the function of sorting shot material from foreign matter. For example, a screw conveyor having a magnetic sorting function may be used as the conveying mechanism.

The above example describes the separation of sand and magnetic particles from the powder and granular material generated when molding sand is removed from a cast product by shot blasting. However, the present invention is not limited to this. The magnetic separator of the present invention can be used effectively when processing large quantities of workpieces. For example, it can be used to separate magnetic particles and non-magnetic particles (molding sand) from the powder and granular material generated by crushing a casting mold (sand mold). For example, it can be used to separate magnetic and non-magnetic materials generated when blasting using a shot blasting machine, such as in the recycling of solar panels. For example, it can be used to separate magnetic and non-magnetic particles from slag generated at a steel mill after crushing it.

1, 10, 50 Magnetic separator 2 Powder and granular mixture supply unit (supply unit)
3 Rotating drum 31 Outer surface of rotating drum 4, 40 First magnet 5 Guide plate 51 Conveying mechanism (belt conveyor)
52 Endless belts 53, 54 Pulley 55 Second magnet 500 Drive mechanism 7 Powdered granular mixture 71 Shot material 72 Foreign matter 8 Falling path G Sorting area P Natural falling area Q Conveying and falling area Q1 Side area Q2 below the conveying and falling area Vertically below the conveying and falling area R Opposite direction to the falling direction

Claims (9)

A magnetic separator that separates and sorts a powdery or granular mixture containing magnetic materials and non-magnetic materials into the magnetic materials and the non-magnetic materials,
a powdery or granular mixture supply unit that supplies the powdery or granular mixture and allows it to fall naturally;
a rotating drum having a part of its outer surface positioned in a falling path, which is a path along which the powdery or granular mixture falls naturally, and which is rotated in a direction opposite to the falling direction of the powdery or granular mixture;
a guide plate provided in a position facing the outer surface of the rotary drum on the falling path, for bouncing back the magnetic material that collides with the rotary drum and is thrown off, and returning the magnetic material to the rotary drum;
a first magnet supported inside the rotating drum, the first magnet applying a magnetic attraction force to a certain area of the outer surface in the reverse direction starting from a sorting area where a path along which the powdery mixture naturally falls contacts the outer surface of the rotating drum;
a free-fall region in which the powdery or granular mixture that has come into contact with the rotating drum falls naturally;
a conveying and falling area in which the powdery and granular mixture is magnetically attracted to the rotating drum, conveyed, and naturally falls ,
A magnetic separator configured such that, in a circumferential direction from the starting point of the rotating drum in the reverse direction, a certain area of the outer surface to which the magnetic attraction force is applied is larger than the remaining area of the outer surface to which the magnetic attraction force is not applied . the first magnet is provided so as to apply a magnetic attraction force to the outer surface of the rotating drum, the end point of the fixed region being at a lower portion in the vertical direction of the rotating drum;
2. The magnetic separator according to claim 1, wherein the powdery mixture magnetically attracted to and transported by the first magnet is sorted and allowed to fall naturally into a side lower region of the transport and fall region of the rotating drum and an adjacent region vertically below the transport and fall region of the rotating drum. The magnetic separator according to claim 2, further comprising a wind separator that separates the powdery and granular mixture that has naturally fallen into the area vertically below the conveying and falling area into magnetic and non-magnetic materials using wind force. A magnetic separation device according to any one of claims 1 to 3, wherein a transport mechanism having the function of further separating the magnetic materials from the non-magnetic materials is disposed in at least one of the free-fall area and the transport/fall area. The transport mechanism has a free fall area and a transport fall area.
5. The magnetic separator according to claim 4, further comprising: a drive mechanism including a pair of pulleys; and an endless belt wound around the pair of pulleys, wherein a second magnet is disposed inside one of the pulleys to apply a magnetic attraction force to the outer surface of the pulley. A magnetic separator according to any one of claims 1 to 5, wherein the powdery/granular mixture is shot material and molding sand generated by removing molding sand adhering to a casting after casting using shot blasting. A magnetic separation method for separating and separating a powdery or granular mixture containing magnetic materials and non-magnetic materials into the magnetic materials and the non-magnetic materials, comprising:
Allowing the powdery or granular mixture to fall naturally;
a rotating drum having a part of its outer surface positioned in a path along which the powdery or granular mixture falls naturally, said rotating drum rotating in a direction opposite to the falling direction of the powdery or granular mixture;
bouncing the magnetic material that has collided with the rotating drum and been thrown off, back to the rotating drum;
applying a magnetic attraction force to a certain area of the outer surface in the reverse direction starting from a sorting area where a path along which the powdery mixture naturally falls comes into contact with the outer surface of the rotating drum, so that the certain area of the outer surface to which the magnetic attraction force is applied is larger than the remaining area of the outer surface to which the magnetic attraction force is not applied, in a circumferential direction of the rotating drum from the starting point in the reverse direction ;
and separating and sorting the powdery/granular mixture into a free-falling region where the powdery/granular mixture falls naturally and a transport/falling region where the powdery/granular mixture is magnetically attracted to the rotating drum, transported, and then free-falls. applying a magnetic attraction force to the outer surface of the rotating drum, the end point of the certain region being at the lower part in the vertical direction of the rotating drum;
8. The magnetic separation method according to claim 7, further comprising the step of allowing the powdery or granular mixture, which is magnetically attracted to and transported by the rotating drum, to fall naturally into a side lower region of the transport and fall region below a side portion of the rotating drum and into an adjacent vertically lower region of the transport and fall region below a vertically lower portion of the rotating drum. The magnetic separation method described in claim 7 or 8, wherein the powdery/granular mixture is shot material and molding sand generated by removing molding sand adhering to a casting after casting using shot blasting.