JP2003211022A - Method and apparatus for removing magnetic foreign matter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To maintain the removing ability of a magnetic foreign matter always constant by preventing the formation of a mountain of powder, a dumpling, or the like. <P>SOLUTION: A chamber 1 includes a feed port 3 into which object materials 2 consisting of powder or a grain are introduced, and a discharge port 4 from which the object materials 2 are discharged. The chamber 1 introduces the object materials 2 from the feed port 3, moves them in a predetermined direction, and discharges them from the discharge port 4. A magnetic foreign matter removal chamber 5 is formed in the chamber 1. This magnetic foreign matter removal chamber 5 includes: a plurality of bar magnets 8 which are arranged orthogonally to the moving direction of the object materials 2, and adsorb and eliminate a magnetic foreign matter mixed in the object materials 2 with magnetic force; and air injection pipes 9 which remove the object materials 2 adhering to the surface of each bar magnet 8 by injecting air. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic foreign substance removing method and apparatus for removing magnetic foreign substances such as magnetic powder mixed with a target substance composed of powder or fluid.

[0002]

2. Description of the Related Art In the manufacturing process of powdered or granular foods, medicines, etc., metal powder etc. Foreign matter may be mixed in. In order to remove the metal powder and the like mixed in the raw materials such as granules and powders in this way, a magnetic foreign matter removing device as disclosed in, for example, JP-A-8-24791 has been conventionally used. In this type of magnetic foreign matter removing device, a target substance composed of powder or granules introduced into a fluidized bed chamber moves to a plurality of bar magnets arranged in the chamber in the process of moving in the fluidized bed chamber. The metal powder or the like that comes close to or comes into contact with and mixes with the target substance is adsorbed and removed by magnetic force.

[0003]

In the bar magnet used in the above-mentioned magnetic substance foreign matter removing apparatus, since the magnetic poles are formed at a predetermined interval in the longitudinal direction, the magnetic pole portion is removed in the process of removing the metal powder and the like. In some cases, the metal powder is intensively adsorbed on the metal powder, and the powder or granules that are the target substance adheres to this portion to form a so-called powder mountain. In particular, fine powder such as Meriken powder tends to adhere to the surface of the magnet with a repose angle corresponding to the powder to form powder hills. In addition, the powder and the iron powder may be kneaded in the state of being kneaded on the surface of the magnet. When such powder hills, dumplings, etc. are formed, there is a problem in that the adsorption of the metal powder to be removed onto the bar magnet is hindered and the removal capability is reduced. Further, when powder particles, dumplings, or the like are formed on the bar magnet, there is a problem that the passage cross-sectional area of the flow channel is reduced and the yield is reduced, or in an extreme case, the flow channel is closed. Therefore, it is conceivable to use an air knocker or a vibrator to break up the powder hills, but this is not so effective even if the device is oversized.

The present invention has been made in view of the above problems, and it is possible to prevent the generation of dust particles, dumplings, and the like, and to always maintain a constant magnetic foreign matter removal ability. It is an object to provide a method and a device.

[0005]

According to the method for removing magnetic foreign matter according to the present invention, a magnet is arranged in a moving path of a target substance made of powder or granules to remove magnetic foreign substances mixed in the target substance. The target substance adhered to the surface of the magnet by adsorption is removed by jetting air.

According to the present invention, the target substance adhering to the surface of the magnet is removed by jetting air, so that dust particles or dumplings are not generated on the surface of the magnet, and the magnetic substance of the magnet is not generated. The contact area with the foreign matter is secured, and the magnetic foreign matter can always be favorably removed. In order to further enhance the effect of the present invention, the air jet force is such that the target substance consisting of powder or granules forming powder mountains, dumplings, etc. is surely blown off, and magnetic foreign matter attached to the bar magnet is not blown off. It is desirable to set it to a degree.

Further, the magnetic foreign substance removing apparatus according to the present invention comprises an inlet for introducing the target substance composed of powder or granules and an outlet for discharging the target substance. A chamber which is introduced from above and is moved in a predetermined direction to be discharged from the discharge port, and a magnetic foreign substance which is arranged inside the chamber so as to be orthogonal to the moving direction of the target substance and is mixed into the target substance. It is characterized by comprising a plurality of bar magnets that are attracted and removed by a magnetic force, and an air ejecting unit that ejects the target substance adhering to the surface of each bar magnet by ejecting air.

According to the present invention, the target substance adhering to the surface of each bar magnet is removed by jetting air from the air jetting means, so that powder particles, dumplings or the like are generated on the surface of the bar magnet. In this case, the contact area of the bar magnet with the magnetic foreign matter is secured, and the magnetic foreign matter can be always removed satisfactorily. The present invention also has the effect of causing powder or particles to fly (disperse) in the chamber by jetting air. In order to further enhance the effect of the present invention, the air jetting force of the air jetting means is such that the target substance consisting of powder or granules forming powder mountains, dumplings, etc. is surely blown off, and the magnetic substance adhered to the bar magnet. It is desirable that the foreign matter is set so as not to be blown off.

More preferably, the air ejecting means is arranged in parallel with the bar magnets at a position upstream of the bar magnets in the direction of movement of the target substance and ejects air toward the bar magnets. It is composed of a plurality of air injection pipes formed with the air nozzles. With such a configuration, it is possible to effectively remove dust particles, dumplings, or the like by injecting air from the upstream side toward the upstream side of the bar magnet on which the dust particles, dumplings, or the like are formed. .

In a more preferred embodiment of the present invention,
A plurality of the bar magnets are arranged at predetermined intervals in the longitudinal direction and a direction orthogonal to the moving direction of the target substance, and the air injection pipes are arranged in the middle of the adjacent bar magnets. A plurality of air nozzles for respectively injecting air toward According to this structure, the upstream side of the bar magnet becomes an open space in which the air injection pipe is not arranged, so that the foreign substance can be reliably contacted with the magnetic foreign substance to enhance the foreign substance removing ability.

Further, in a further preferred embodiment of the present invention, the bar magnets have magnetic poles formed at predetermined intervals in a longitudinal direction thereof, and the air injection pipe is configured to direct air toward each magnetic pole of the bar magnet. A plurality of nozzles for ejecting is formed at predetermined intervals in the longitudinal direction. By injecting air toward the magnetic poles in this way, it is possible to effectively prevent the formation of powder hills, dumplings, and the like.

The air jetting means may comprise a plurality of air nozzles formed in the bar magnets for jetting air from the inside to the outside of each bar magnet. In this case, the air injection pipe can be omitted.

Further, when an air lock mechanism such as a rotary valve for transporting the target substance is provided at each of the upstream end and the downstream end of the chamber in the moving direction of the target substance, the air lock mechanism ensures the airtightness in the chamber. Increase. In this case, since the pressure in the chamber increases, it is desirable to provide a filter so that the air in the chamber is discharged to the outside by this filter.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic cross-sectional view showing the configuration of a magnetic substance foreign matter removing apparatus according to an embodiment of the present invention. The chamber 1 has a vertical cylindrical shape, and has an inlet 3 into which the target substance 2 made of powder or granules is introduced at the upper end, and an outlet 4 from which the target substance 2 is discharged into the lower end. Magnetic foreign matter removing chamber 5 for removing foreign matter
To form. In the upper stage of the inlet 3 and the lower stage of the outlet 4,
Rotary valves 6 and 7 are arranged respectively, and these rotary valves 6 and 7 supply the target substance 2 into the magnetic foreign matter removing chamber 5 by a fixed amount, respectively.
The target substance 2 which has moved from the upper side to the lower side by gravity is discharged to the outside in a constant amount.

In the magnetic foreign matter removing chamber 5, a plurality of bar magnets 8 are arranged so as to be orthogonal to the moving direction of the target substance 2.
Are arranged vertically and horizontally at regular intervals. As shown in FIG. 2A, the bar magnet 8 includes a plurality of ring-shaped permanent magnets 22 mounted on a shaft 21 and a ring-shaped yoke 2.
3 are alternately arranged, and these are housed in a cylindrical container 24 made of a non-magnetic material, and both ends are end plugs 25, 26.
It is sandwiched by screws 27 and the like. The permanent magnet 22 is magnetized in the axial direction and is arranged so that the same poles face each other, as shown in an enlarged view in FIG. As a result, the magnetic force lines extend in the radial direction from the peripheral portion of the yoke 33, and the magnetic force lines extend toward the adjacent yoke 23. Metal powder is adsorbed on the outer peripheral surface of the bar magnet 8 and separated from the target substance 2.

On the other hand, inside the magnetic substance foreign matter removing chamber 5, each bar magnet 8 is located at a position upstream of the target substance 2 in the moving direction of each bar magnet 8 and at an intermediate position between the adjacent bar magnets 8. The air injection pipe 9 is arranged in parallel. As shown in FIG. 3, the air injection pipe 9 has a plurality of nozzles 9a for injecting air toward the magnetic poles 8a of the adjacent bar magnets 8 at predetermined intervals in the longitudinal direction. A filter 10 for exhausting the air jetted from the air jet pipe 9 to the outside of the chamber 1 is provided on both sides of the inlet 3 at the upper end of the chamber 1.

Next, the operation of the magnetic foreign material removing apparatus according to this embodiment having the above-described structure will be described. The target substance 2, which is a powder or granules supplied from a grinder such as an automill (not shown), is passed through the rotary valve 6 on the upstream side and a fixed amount of the target substance 2 in the chamber 1 is removed.
Will be introduced to. The target substance 2 passes through the chamber 1 from the upper side to the lower side, while magnetic foreign substances such as metal powder mixed in the target substance 2 are adsorbed and removed by the bar magnet 8. The target substance 2 from which the magnetic foreign matter has been removed is discharged from the chamber 1 via the rotary valve 7 in a fixed amount to the outside.

By depositing the target substance 2 on the bar magnet 8 in the course of this treatment, powder particles 11 as shown in FIG. 1 are formed. However, the dust 11 is periodically or continuously removed by the air jetted from the nozzle 9a of the air jet pipe 9. Since the rotary valves 6 and 7 as air lock mechanisms are arranged at the upper and lower ends of the chamber 1, the inside of the chamber 1 is sealed,
Since the air flow from the outside is cut off, there is an effect that the target substance 2 is uniformly dispersed, but the nozzle 9 of the air injection pipe 9
By injecting air from a, the pressure in the chamber 1 increases. When the pressure in the chamber 1 rises in this way, the air in the chamber 1 is exhausted to the outside via the filter 10, so the rise in pressure in the chamber 1 is suppressed. With such a configuration, it is possible to prevent the target substance 2 from being deposited on the bar magnet 8 and stably remove the metallic foreign matter.

FIG. 4 is a diagram for explaining another embodiment of the present invention. In this embodiment, instead of the air injection pipe 9, air is ejected from the inside to the outside of the bar magnet 8 '. The same figure (a), (b)
As shown in FIG. 5, the cylindrical container 24 'of the bar magnet 8'has a nozzle 31 formed in a portion corresponding to the magnetic pole 8a' on the upstream side of the target substance 2. The nozzle 31 is shown in FIG. As described above, the air supplied from the outside is discharged to the air passage 32 by communicating with the air passage 32 formed in the cylindrical container 24 ′. Nozzle 3 from which air is discharged
The powder does not adhere to the portion 1 and it is possible to prevent the generation of the powder mountain 11. According to this configuration, the air ejection pipe 9 is unnecessary.

5 also has a bar magnet 8 ″ provided with a nozzle 41 as in the embodiment of FIG.
The nozzle 41 is positioned at both sides of the position of the magnetic pole 8a ″ of the cylindrical container 24 ″ as shown in FIG. 11A, and is inclined toward the magnetic pole 8a ″ side as shown in FIG. The nozzle 41 also communicates with the air passage 42 formed in the cylindrical container 24 ″ and discharges the air supplied from the outside to the air passage 42. Also in this case, the same effect as that of the above embodiment can be obtained.

In the above embodiments, a cylindrical bar magnet is used as a magnet for removing magnetic foreign matter, but the shape of the magnet, such as a magnet having a rectangular cross section, has a capability of removing magnetic foreign matter. Of course, it is not limited. In addition to the rotary valve described above, a choke valve, a slide gate, or the like can be used as the airlock mechanism.

[0022]

As described above, according to the present invention, the target substance adhering to the surface of the magnet is removed by jetting air, so that dust particles, dumplings or the like are generated on the surface of the magnet. Therefore, the contact area of the magnet with the magnetic foreign matter is secured, and the magnetic foreign matter can be always removed satisfactorily.

[Brief description of drawings]

FIG. 1 is a schematic vertical cross-sectional view of a magnetic substance foreign matter removing device according to an embodiment of the present invention.

FIG. 2 is a sectional view of a bar magnet used in the apparatus, FIG. 2A is an overall sectional view, and FIG. 2B is a partially enlarged sectional view.

FIG. 3 is a perspective view showing a configuration of a bar magnet and an air ejection nozzle used in the apparatus.

4A and 4B are diagrams showing a configuration of a bar magnet according to another embodiment of the present invention, wherein FIG. 4A is an external perspective view and FIG. 4B is a partially enlarged sectional view.

5A and 5B are views showing a configuration of a bar magnet according to still another embodiment of the present invention, wherein FIG. 5A is an external perspective view and FIG. 5B is a partially enlarged sectional view.

[Explanation of symbols]

1 ... Chamber 2. Target substance 3 ... Inlet 4 ... outlet 5 ... Magnetic foreign matter removal chamber 6, 7 ... Rotary valve 8,8 ', 8 "... Bar magnet 8a, 8a ', 8a "... Magnetic poles 9 ... Air injection pipe 9a, 31, 41 ... Nozzle 10 ... Filter

Claims (7)

[Claims] 1. A target substance adhered to the surface of the magnet by arranging a magnet in a movement path of the target substance consisting of powder or granules to adsorb and remove magnetic foreign matter mixed in the target substance by magnetic force. A magnetic foreign material removing method, characterized in that the air is removed by jetting air. 2. An inlet for introducing a target substance, which is a powder or granules, and an outlet for discharging the target substance are provided, and the target substance is introduced from the inlet and moved in a predetermined direction. A chamber for discharging from an outlet, and a plurality of bar magnets disposed inside the chamber so as to be orthogonal to the moving direction of the target substance and attracting and removing magnetic foreign matter mixed in the target substance by magnetic force An apparatus for removing a magnetic foreign substance, comprising: an air ejecting unit that ejects the target substance attached to the surface of each bar magnet by ejecting air. 3. The plurality of air nozzles, which are arranged in parallel to the bar magnets at positions upstream of the bar magnets in the direction of movement of the target substance, and inject the air toward the bar magnets. The magnetic foreign material removing device according to claim 2, wherein the magnetic foreign material removing device is composed of a plurality of air injection pipes formed with. 4. A plurality of the bar magnets are arranged at predetermined intervals in a direction orthogonal to a longitudinal direction of the bar magnet and a moving direction of the target substance, and the air injection pipe is arranged in the middle of adjacent bar magnets. 4. The magnetic foreign matter removing device according to claim 3, wherein a plurality of air nozzles for respectively injecting air toward the bar magnets on both sides are formed. 5. The bar magnet has magnetic poles formed at predetermined intervals in the longitudinal direction, and the air injection pipe has a plurality of nozzles in the longitudinal direction for injecting air toward each magnetic pole of the bar magnet. The magnetic foreign material removing device according to claim 3 or 4, wherein the magnetic foreign material removing device is formed at a predetermined interval. 6. The air jetting means comprises a plurality of air nozzles formed in the bar magnets for jetting air from the inside to the outside of each bar magnet. Magnetic foreign matter removal device. 7. An air lock mechanism, which is provided at each of an upstream end and a downstream end of the chamber in the direction of movement of the target substance and seals the inside of the chamber, and a filter for discharging the air in the chamber to the outside. The magnetic foreign matter removing device according to claim 2, further comprising: