JPH11281798A - Electron beam irradiator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electron beam irradiator that can evenly irradiate a target with an electron beam. SOLUTION: Near an irradiation target 2, a coil 212 is wound around a magnetic substance 211 and an electromagnetic device 21 formed by connecting a coil power source 213 to the coil 212 is placed to deflect the irradiating direction of an electron beam 4 to the target 2. Such a placement of the electromagnetic device 21 makes it possible to irradiate the target with the electron beam 4 evenly, so that effective sterilization and disinfection can be conducted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electron beam irradiation apparatus used for sterilizing or sterilizing an object to be irradiated.

[0002]

2. Description of the Related Art Conventionally, as an electron beam irradiation apparatus of this type, as shown in FIG. 8, an electron beam irradiation apparatus main body 3 is arranged on an object 2 to be transferred to a predetermined position by a transfer apparatus 1, and Irradiation object 2 from electron beam irradiation device body 3
Irradiation of an electron beam 4 to the irradiation target 2 produces an irradiation effect such as sterilization, sterilization, or curing depending on the identity (composition, temperature, etc.) of the irradiation target 2.

In this case, the electron beam irradiation device main body 3
Mainly, a vacuum exhaust device 5, a vacuum container 6 whose inside is evacuated by the vacuum exhaust device 5, a cathode 7 for emitting thermoelectrons, and a relatively positive potential applied to the cathode 7 to extract an electron beam 4 And an extraction window 9 which is a partition through which the electron beam 4 passes when the electron beam 4 is extracted from the vacuum vessel 6 to the atmosphere. A cathode power supply 10 is connected between the cathode 7 and the anode 8, and the cathode 7 is connected between the cathode 7 and the ground.
An acceleration power supply 11 for applying a negative potential is connected to the side. In this case, the cathode 7 is electrically isolated from the ground potential by the insulator 12, and the anode 8 is grounded together with the vacuum vessel 6.

[0004] The electron beam irradiation apparatus thus configured generates a potential gradient between the cathode 7 and the anode 8 by applying a voltage between the cathode 7 and the ground. In this state, the cathode 7 is heated by Joule heat generated by the connection of the cathode power supply 10, and the amount of thermoelectrons corresponding to the temperature at this time is emitted. The electron beam 4 is obtained by being accelerated by the acceleration potential gradient by the power supply 11. The electron beam 4 is taken out into the atmosphere through a thin film take-out window 9 capable of withstanding the pressure difference between the atmosphere and vacuum and maintaining the vacuum tightness, and the irradiated object 2 transferred by the transfer device 1. Will be irradiated.

[0005] The energy of the electron beam 4 in this case is determined by the accelerating voltage of the accelerating power supply 11, and this energy corresponds to the penetration depth of the electron beam 4 (the penetration force of the electron beam 4). Therefore, the irradiation target 2
If the energy of the electron beam 4 applied to the object 2 is sufficiently high, uniform irradiation can be performed without being affected by the shape of the object 2 to be irradiated. However, if the energy of the electron beam 4 is increased, the cost for blocking X-rays generated by the irradiation of the electron beam 4 becomes effective. Therefore, it is desirable to use the electron beam 4 having the lowest possible energy according to the purpose. For example, when sterilizing or disinfecting a surface portion of a film or the like, an energy (normally 300 keV) that is low enough to extract the electron beam 4 into the atmosphere without any trouble is sufficient.

[0006]

However, the irradiation target 2
For example, as in a food and beverage container cap 13 shown in FIG. 9A, a shape in which a groove 133 forming the screw portion 132 is formed on the inner peripheral surface of the opening of the bottomed cylindrical cap body 131. On the other hand, when sterilization and sterilization are performed by irradiating the electron beam 4 with low energy, the side wall surface 134 on the bottom surface side is directly irradiated from the screw portion 132 inside the cap main body 131 through the opening of the cap main body 131. The amount of the electron beam 4 is small. Bottom 1 of cap body 131
Even when an electron beam irradiated by reflection from 35 is added, the amount of the electron beam 4 received by the side wall surface 134 is small,
The inside of the cap body 131 cannot be uniformly irradiated. That is, as shown in FIG. 2B, the bottom surface A and the side wall surface C of the inside of the cap body 131 directly irradiated by the electron beam 4 are irradiated with the electrons on the side wall surface B indirectly irradiated by the reflection of the electron beam 4. The irradiation amount of the beam is remarkably reduced, and the sterilization and sterilization effects on the side wall surface B are drastically reduced. Further, the electron beam 4 cannot be irradiated into the groove 133 constituting the screw portion 132. There was a problem that sterilization was not performed.

Therefore, in order to solve such inconveniences, it is conceivable to (1) irradiate an electron beam with a high energy enough to penetrate the groove 133, but in this case, the cost and the installation area (generally, However, the higher the energy is, the larger the occupied area is.)

(2) When the electron beam is irradiated into the groove 133, the electron beam 4 reflected inside the cap body 131
However, since the amount of electron beam irradiation obtained by reflection is remarkably small, sufficient sterilization and sterilization effects cannot be obtained. There is a problem that it takes time, the processing cost becomes enormous, and furthermore, irradiation damage to other parts is caused, such as deterioration of material properties due to irradiation of the electron beam for a long time. The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an electron beam irradiation apparatus that can uniformly irradiate an irradiation target with an electron beam.

[0009]

According to the first aspect of the present invention,
In an electron beam irradiation apparatus that sterilizes and sterilizes an object by irradiating the object with an electron beam, a magnet device that deflects the irradiation direction of the electron beam is arranged near the object to be irradiated.

According to a second aspect of the present invention, in the first aspect of the invention, the magnet device comprises an electromagnet. According to a third aspect of the present invention, in the first aspect, the magnet device includes a permanent magnet. According to a fourth aspect of the present invention, in the second or third aspect, the magnet device is arranged such that a plurality of electromagnets or permanent magnets have different magnetic flux generation directions.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. (First Embodiment) FIG. 1 shows a schematic configuration of an electron beam irradiation apparatus to which the present invention is applied, and the same parts as those in FIG. 8 are denoted by the same reference numerals.

In this case, an example of a cap 13 of a food and drink container similar to that described with reference to FIG. Then, the electron beam irradiation device main body 3 of the non-magnetic material transfer device 1 for transporting such a food and beverage container cap 13
Electromagnetic device 2 for electron beam orbit deflection at a position corresponding to
1 is provided.

The electromagnet device 21 has a U-shaped magnetic body 2.
11, a coil power supply 213 is connected to the coil 212. When the coil 212 is energized by the coil power supply 213, an external magnetic flux 22 is generated from the U-shaped magnetic body 211. The external magnetic flux 22 is transmitted through the food and beverage container cap 13 on the transfer device 1.

Next, the operation of the embodiment configured as described above will be described. First, the food and beverage container cap 13 is placed on the transfer device 1 and transferred in a predetermined direction. When the cap 13 reaches a predetermined position corresponding to the electron beam irradiation device main body 3 by this transfer, the electron beam irradiation device main body 3
The electron beam 4 is irradiated toward the cap 13.

In this case, the cap 13 is irradiated with the electron beam 4 in a state where the coil 212 is not energized by the coil power supply 213 and the magnetic material 211 does not generate the external magnetic flux 22. Then, the electron beam 4 passes through the opening of the cap body 131 and is directly applied to the side wall surface and the bottom surface in the cap body 131, and is partially reflected on the bottom surface and indirectly applied to the side wall surface. Sterilization and sterilization of 131 are performed.

Next, the coil 21 is controlled by the coil power supply 213.
2, an external magnetic flux 22 is generated from the magnetic body 211 and transmitted through the cap 13. Then, the electron beam 4 generated by the electron beam irradiation device main body 3 has a radius of curvature (Larmor radius) determined in proportion to the momentum (depending on energy) of the electron beam in the magnetic field generated by the external magnetic flux 22 and inversely proportional to the magnetic field strength. ) Causes a deflection in its trajectory.

As a result, for example, as shown in FIG. 2, the electron beam 4 is
Is deflected to the left so that the side wall surface in the cap body 131 can be directly irradiated. In this case, as shown in FIG. 3, the electron beam 4 directly irradiating the side wall surface of the cap body 131 also directly enters the groove 133 constituting the screw portion 132 where beam irradiation was difficult in the absence of the external magnetic flux 22. Since irradiation can be performed, effective sterilization and sterilization can be performed even in a portion which has been hitherto a blind spot in processing. Further, the direction in which the electron beam 4 is deflected by the external magnetic flux 22 can be alternately switched between the solid line direction and the broken line direction as shown in FIG.
The electron beam 4 can be directly applied to the inner side wall surface in a wide range. Further, by using the electromagnet device 21, by controlling the current supplied from the coil power supply 213 to the coil 212, the magnitude of the deflection of the electron beam 4 can be arbitrarily obtained. The irradiation angle of the electron beam 4 can be set to an optimum value according to the conditions.

Incidentally, inside the cap body 131,
In order to directly irradiate the electron beam 4 over a wider range, as shown in FIG. 4, a plurality of electromagnet devices 21 are prepared, and the generation directions of the external magnetic flux 22 of these electromagnet devices 21 are partially or entirely different. By doing so, the deflection direction of the electron beam 4 by the external magnetic flux 22 generated by the electromagnet device 21 can be set in multiple directions, so that the entire inside of the cap body 131 can be irradiated with the electron beam 4 from multiple directions. As a result, more effective sterilization and sterilization can be performed.

Further, the coil 21 by the coil power supply 213
(2) The alternating current power supply having a frequency and a waveform in consideration of the transport speed when transporting the cap 13 is used to generate an alternating magnetic field, so that the irradiation of the electron beam 4 can be performed with lower energy. Can also. (Second Embodiment) FIG. 5 shows a schematic configuration of a second embodiment of the present invention, and the same parts as those in FIG. 1 are denoted by the same reference numerals.

In this case, the object 31 to be irradiated 2
1 shows an example of a container 31 such as a bottle with a narrowed one. An electromagnet device 32 for deflecting the electron beam orbit is provided at a position corresponding to the electron beam irradiation device main body 3 of a transfer device (not shown) for transporting such a container 31.

The electromagnet device 32 comprises a magnetic body 321 provided to surround the container 31 except for the opening 311, a coil 322 wound around the magnetic body 321, and a coil power supply 323. When the coil 322 is energized by 323, an external magnetic flux 324 is generated from the magnetic body 321, and the external magnetic flux 33 is transmitted through the container 31.

Next, the operation of the embodiment configured as described above will be described. First, the container 31 is placed on the transfer device,
Transfer in a predetermined direction. And, by this transfer, the container 31
Reaches a predetermined position corresponding to the electron beam irradiation device main body 3, the electron beam 4 is irradiated from the electron beam irradiation device main body 3 toward the container 31.

In this case, first, the coil 322 is not energized by the coil power supply 323, and the electron beam 4 is applied to the container 31 in a state where the external magnetic flux 33 is not generated from the magnetic body 321.
Is irradiated. Then, the electron beam 4 is directly irradiated to the bottom surface in the container 31 through the opening 311 of the container 31, and is partially reflected on the bottom surface and indirectly irradiated to the side wall surface, thereby sterilizing the inside of the container 31. Perform sterilization.

Next, the coil 32 is supplied by the coil power supply 323.
2, an external magnetic flux 33 is generated from the magnetic body 321 and is transmitted through the container 31. As a result, as shown in FIG. 6, the electron beam 4 is deflected by the external magnetic flux 33 in a direction perpendicular to the plane of the paper, so that the side wall surface in the container 31 can be directly irradiated. In this case, the electron beam 4 deflected by the external magnetic flux 324, when no external magnetic flux 33 exists,
Opening 311 side wall surface and opening 3 where beam irradiation was difficult
Since it is also possible to directly irradiate the constricted portion 311a of the eleventh part, effective sterilization and sterilization can be performed even in a part which has hitherto been a blind spot of processing.

Also in this case, an alternating magnetic field can be generated by energizing the coil 322 by the coil power supply 323 by using an AC power supply having a frequency and a waveform in consideration of the transfer speed when the container 31 is transferred. Thus, the irradiation of the electron beam 4 can be handled with low energy. (Third Embodiment) FIG. 7 shows a schematic configuration of a third embodiment of the present invention.

In this case, a plurality of permanent magnets 41 are prepared as a magnet device for deflecting the electron beam orbit, and the generation directions of the external magnetic flux 42 of these permanent magnets 41 are partially or entirely changed. I have.

Also in this case, since the deflection direction of the electron beam 4 by the external magnetic flux 42 generated by the permanent magnet 41 can be set in multiple directions, the electron beam 4 is uniformly applied to the entire inside of the irradiation target 43. Irradiation can be performed, and effective sterilization and sterilization can be expected. Further, by using the permanent magnet 41, the device configuration can be obtained at low cost.

[0028]

According to the first aspect of the present invention, by arranging the magnet device for deflecting the irradiation direction of the electron beam near the object to be irradiated, the object to be irradiated is uniformly irradiated with the electron beam. And effective sterilization and sterilization can be performed.

According to the second aspect of the present invention, the magnitude of the deflection of the electron beam can be arbitrarily obtained by using an electromagnet as the magnet device, so that the irradiation angle of the electron beam can be adjusted according to the state of the beam irradiation surface. Can be set to the optimal one.

According to the third aspect of the present invention, by using a permanent magnet as the magnet device, the magnitude of deflection of the electron beam can be stably obtained. According to the fourth aspect of the present invention, by arranging a plurality of electromagnets or permanent magnets with different directions of magnetic flux generation, the deflection direction of the electron beam can be set in multiple directions. Irradiates an electron beam, and effective sterilization and sterilization can be performed.

[Brief description of the drawings]

FIG. 1 is a diagram showing a schematic configuration of a first embodiment of the present invention.

FIG. 2 is a diagram for explaining the first embodiment.

FIG. 3 is a diagram for explaining the first embodiment.

FIG. 4 is a diagram showing a schematic configuration of an example of an electromagnet device used in the first embodiment.

FIG. 5 is a diagram showing a schematic configuration of a second embodiment of the present invention.

FIG. 6 is a diagram for explaining the operation of the second embodiment.

FIG. 7 is a diagram showing a schematic configuration of a magnet device used in a third embodiment of the present invention.

FIG. 8 is a diagram showing a schematic configuration of an example of a conventional electron beam irradiation apparatus.

FIG. 9 is a view for explaining a conventional electron beam irradiation apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Transfer device, 2 ... Irradiation object, 3 ... Electron beam irradiation device main body, 4 ... Electron beam, 5 ... Vacuum exhaust device, 6 ... Vacuum container, 7 ... Cathode, 8 ... Anode, 9 ... Extraction window, 10 ... Cathode power supply 11 Acceleration power supply 12 Insulator 13 Food and beverage container cap 131 Food cap body 132 Screw part 133 Electromagnetic device 21 Electromagnet device 211 Magnetic material 212 Coil 213 Coil Power supply, 22: external magnetic flux, 31: container, 311: opening, 311a: constricted part, 32: electromagnet device, 321: magnetic material, 322: coil, 323: coil power supply, 41: permanent magnet, 42: external magnetic flux.

Claims (4)

[Claims] An object to be irradiated is irradiated with an electron beam and sterilized.
An electron beam irradiation apparatus for sterilizing, wherein a magnet device for deflecting the irradiation direction of the electron beam is disposed near the object to be irradiated. 2. The electron beam irradiation apparatus according to claim 1, wherein the magnet device is an electromagnet. 3. The electron beam irradiation device according to claim 1, wherein the magnet device is a permanent magnet. 4. The electron beam irradiation apparatus according to claim 2, wherein the magnet device is arranged such that a plurality of electromagnets or permanent magnets generate magnetic fluxes in different directions.