JP2002006098A - Method and device for electron beam irradiation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high productive electron beam irradiation method and its device where electron beam is efficiently projected to an object to exclude wasting of electron beam and electric power. SOLUTION: An electron beam irradiation device 30 is provided where a solid object 11 is transported in a specified direction while irradiated with electron beam for sterilization and the like. Here, there are provided a roller conveyor 12 for transporting the objects 11 with appropriate interval, an irradiation conveyor 14 which is slower than the roller conveyor 12, positioned on its lower stream side, and transports the object in tight-contact manner, a skew conveyor 13 which, positioned between the two conveyors, comprises a putting- aside means for putting the objects 11 aside in a specified direction, and a stopper 17 which is at least provided on an outlet side of the roller conveyor 12 and temporarily stops the object 11. An electron beam accelerator 10 for projecting electron beam 20 is so provided as to face the irradiation conveyor 14.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an initial object such as sterilization by irradiating a high-energy electron beam to an irradiated object while conveying the object having a three-dimensional shape such as a medical device. The present invention relates to a method and an apparatus for irradiating an electron beam.

[0002]

2. Description of the Related Art Conventionally, high-pressure steam sterilization, ethylene oxide gas sterilization, γ-ray sterilization, electron beam irradiation sterilization, and the like have been used for sterilization of medical equipment and drinking water containers. Among them, the electron beam irradiation sterilization method enables sterilization of medical equipment and the like by increasing the acceleration voltage of the electron beam, and there is no concern about heat resistance and residual toxicity of the irradiated object,
Furthermore, sterilization can be performed in a very short time, and irradiation is stopped instantly when the power is turned off. This has the advantages of high environmental safety and low cost. . Further, the difference from γ-ray irradiation is that it is said that material deterioration is small. For this reason, there is a possibility that the range of material selection may be expanded. As described above, it has a certain thickness or more, and in particular, when sterilizing a medical device as described above, it is necessary to irradiate a sufficient amount of an electron beam. Energy electron beams are not sufficient, and electron beams of 5 to 10 MeV having electron beam energies close to the upper limit allowed for industrial applications are often used.

[0003]

However, such a high energy electron beam consumes relatively large power,
Since an electron beam is also expensive, it is an important task to eliminate the waste of electric power and maximize the use of the electron beam. Figure 1
As shown in the conventional transfer method shown in (b), since the irradiation conveyor 14 as the transfer means is operated at a predetermined speed, the irradiated objects 11 are placed and transferred on the conveyor 14 at regular intervals. Is done. For this reason, the space between the irradiation objects 11 is irradiated with the electron beam 20, and as described above,
Electron beams and power are wasted. A method of stopping the irradiation of the electron beam when the irradiation target 11 is not in the electron beam irradiation area is also considered, but the operation of the electron beam accelerator becomes complicated, which is not preferable.

As shown in FIG. 3B, in the prior art, the irradiation target 11 is a fixed guide rail 1 provided on both sides of an irradiation conveyor 14 and having a fall prevention function.
Widthwise position between 6 when being conveyed is indeterminate, and it is inevitable to significantly wider than the electron beam irradiation width A ₂ of the irradiated object width A, again useless irradiation of the electron beam is a problem Become. Also,
Amplitude large next to the electron beam accelerator by increasing the electron beam irradiation width A _2, which the density of the electron beam is lowered, the processing amount per unit time is reduced, productivity is lowered. Therefore, the present invention solves the above-mentioned problem, eliminates waste of electron beams and power by efficiently irradiating an electron beam to an object to be irradiated, and has an electron beam irradiation method with high processing efficiency and high productivity, and its method. It is intended to provide a device.

[0005]

In order to solve the above-mentioned problems, the present invention is directed to the invention as defined in claim 1, wherein an object is irradiated with an electron beam while conveying a three-dimensional object to be irradiated in a predetermined direction, such as sterilization. The electron beam irradiation apparatus that achieves the above object has a first transporting step of transporting the object to be irradiated at appropriate intervals, and a second transporting step that is located downstream thereof and closely transports the object to be irradiated. Then, the object to be irradiated is irradiated with an electron beam in the second transporting step.

As described above, the objects to be irradiated are placed on a conveyor at appropriate intervals due to the influence of the transport system, and are carried into a sterilization chamber for performing an electron beam irradiation process. An object of the present invention is to eliminate a useless irradiation of an electron beam by providing a second transporting step of transporting the irradiated object in a state of being brought into close contact therewith. This is because, as shown in FIG. 1A, the object to be irradiated 11 which is closely transported on the irradiation conveyor 14 in the second transporting step is irradiated with the electron beam 20, so that the object to be irradiated is Processing can be continuously and efficiently performed, and unnecessary irradiation of electron beams can be eliminated. By providing these two transporting steps, the object to be irradiated can be sterilized continuously and efficiently, and unnecessary irradiation of electron beams and electric power can be significantly reduced.

According to a second aspect of the present invention, the speed of the first transporting step is increased, the speed of the second transporting step is reduced, and at least the outlet side of the first transporting step is provided. There is a stopping means for temporarily stopping the irradiation object. This invention is one of the methods for bringing the irradiated object into close contact with each other, wherein the speed of the first transporting step is set to be higher than that of the second transporting step, so that the irradiated object can be irradiated in the second transporting step. And a stopping means such as a stopper operated by compressed air is provided at least on the outlet side of the first transporting step, and the stopper is released every predetermined time to control the distance between the irradiation objects. The object is brought into close contact with the object. As described above, by controlling the difference between the respective transport speeds and the stopping means, the object to be irradiated is subjected to the electron beam irradiation in the second step in a state of being in close contact with the object. Useless irradiation can be eliminated. Further, by setting the respective transport speeds in this manner, the speed of the first transport step can be increased,
Productivity is improved.

According to a third aspect of the present invention, there is provided a third conveying apparatus having a biasing means for biasing and aligning an irradiation object in a predetermined direction between the first transporting step and the second transporting step. The method is characterized in that a process exists. As described above, when irradiating the irradiation object with the electron beam, the irradiation width of the electron beam must be larger than the irradiation object width.
According to the invention, a third transporting step is provided on the upstream side of the electron beam irradiation area, and the third transporting step is biased toward one of the guide rails located on both side surfaces of the transporting conveyor, Since the electron beam irradiation width can be reduced, the electron beam density is increased and efficient irradiation is possible, and unnecessary irradiation of the electron beam can be eliminated.

Further, as an apparatus for effectively carrying out the above-mentioned method, the invention according to claim 4 aims at an intended object such as sterilization by irradiating an electron beam while transporting a three-dimensional object in a predetermined direction. In the electron beam irradiation apparatus to be achieved, a first conveying means for conveying the object to be irradiated at appropriate intervals, and a second means for closely conveying the object to be irradiated, which is located downstream of the first conveying means at a lower speed than the first conveying means. Transport means, a third transport means provided between the two transport means and a biasing means for biasing and aligning the irradiation target in a predetermined direction, and at least an outlet side of the first transport means And a stopper means for temporarily stopping the object to be irradiated, and an electron beam accelerator for irradiating the electron beam is provided facing the second transport means.

According to a fifth aspect of the present invention, the speed of each of the transporting means and the interval of cutting out the illuminated object by the stopper means are set so that the illuminated object is closely transported by the second transporting means. It is characterized in that control means for controlling is provided. According to the above configuration, the irradiation target placed with the space maintained in the first transport unit is stopped by the stopper unit located at least on the exit side of the first transport unit, and is released at predetermined time intervals. One or more pieces are cut out by the stopper in a state of being closely or densely arranged. Further, after being aligned in a predetermined direction on a second transporting means having a biasing function such as a skew conveyor positioned at a subsequent stage, the third transporting speed is set to be smaller than that of the first transporting means. The carrier is brought into close contact with the carrier, and is irradiated with an electron beam by an electron beam accelerator provided in the middle of the third carrier. At this time, the irradiation object passes under the electron beam irradiation area in a close contact state and is biased in a predetermined direction, so that the space between the irradiation objects is irradiated with the electron beam. However, since the swing width of the electron beam accelerator can be reduced, electron beam irradiation can be performed at a high density, and sterilization can be performed with high efficiency.

[0011] Further, the invention according to claim 6 is the third invention.
The present invention is characterized in that a predetermined linear distance is provided near the starting end of the conveying means. The second transport means,
A skew conveyor or the like that transports the transferred object while shifting the roller portion of the roller conveyor at a predetermined angle in the transfer direction while shifting the transferred object in the predetermined direction is used. Since the arrangement may be disturbed when passing through the portion, it is necessary to provide the second conveying means with a linear distance such that the irradiated object is completely offset.

Further, according to the present invention, a shielding wall is provided between the stopper means and the electron beam irradiation area so that X-rays generated from the electron beam irradiation area do not directly hit the stopper means. It is characterized by comprising. When a high-energy electron beam is mainly used as in this invention, when the electron beam passes through a substance, a bremsstrahlung phenomenon in which X-rays are emitted in a Coulomb field of a nucleus occurs. Thus, the material constituting the stopper is apt to deteriorate, and in order to prevent such a remarkable reduction in the life of the stopper, by configuring as in claim 7, the deterioration of the stopper is reduced, and the life of the stopper is reduced. Improvement can be achieved.

The stopper means is not limited as long as it can stop the object to be irradiated at predetermined time intervals. However, since a part of the sterilization chamber may receive a certain amount of heat due to the braking X-ray, In particular, a hydraulic stopper or the like is not used for the stopper means.
It is preferable to use a pneumatic stopper that is operated by compressed air.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be illustratively described in detail below with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the invention thereto, unless otherwise specified, and are merely illustrative examples. Not just. FIG. 2 is a side view showing close contact conveyance of the electron beam irradiation apparatus according to the present invention, FIG. 4 is a side view showing one-sided conveyance of the electron beam irradiation apparatus according to the present invention, and FIG. 5 is electron beam irradiation according to the present embodiment. It is a schematic structure figure of an apparatus.

FIGS. 2 and 4 show an embodiment of the present invention.
This will be described with reference to FIG. 2 and 4, reference numeral 10 denotes an electron beam accelerator for irradiating a high-energy electron beam, 11 denotes an object to be irradiated, 12 denotes a roller conveyor, 13 denotes a skew conveyor,
Reference numeral 14 denotes an irradiation conveyor, and reference numeral 30 denotes a 10 MeV electron beam irradiation device. As shown in FIG. 2, such an electron beam irradiation device 3
The transport system of No. 0 is composed of a roller conveyor 12 for transporting the irradiated objects 11 at appropriate intervals, a skew conveyor for transporting the irradiated objects 11 in a one-sided alignment, and an irradiation conveyor 14 including an electron beam irradiation area. You. The roller conveyor 12 is set at a higher speed than the irradiation conveyor and the skew conveyor 13 in order to stably supply the irradiation object 11 to the irradiation conveyor 14. Furthermore, by setting the skew conveyor 13 at a higher speed than the irradiation conveyor 14,
The space between the irradiation objects that are not completely adhered to each other is further reduced by the stopper described later. In this way, by controlling the speed of each conveyor, the object to be irradiated can be reliably brought into close contact with the electron beam irradiation area.

The irradiation object 11 transferred to the irradiation conveyor 14 is subjected to a sterilization treatment for a predetermined time by irradiation of a high energy electron beam irradiated from the electron beam accelerator 10, and
It is again conveyed to the roller conveyor 12 located on the downstream side, and is sent to the next process. A thick beam stop 15 made of SUS or the like is provided immediately below the electron beam accelerator 10 with the irradiation conveyor 14 interposed therebetween. It is configured to receive a line. Further, it is preferable to use a chain conveyor employing a frame through which cooling water flows because of the problem of heat radiation.

As shown in FIG. 4, the skew conveyor 13 has one end of the axis 13a of the roller portion of the roller conveyor 12 fixed and slightly shifted in the traveling direction, and is mounted thereon. As shown in FIG. 3A, the object 11 is conveyed in an oblique traveling direction and is brought into contact with the object 11 and guide rails 16 provided on both side surfaces of the conveyor and having a function of preventing falling. The object 11 is shifted in a predetermined direction and transferred to the irradiation conveyor 14. FIG.
(A), as is clear by comparison with the prior art (b), the electron beam irradiation area A ₁ of the present embodiment can be set smaller than the conventional electron beam irradiation area A ₂ (A ₁ <
A ₂ ), since the electron beam density in the electron beam irradiation area A ₁ is large, it is possible to shorten the electron beam irradiation time per unit area on the irradiation object, thereby improving the productivity. , Waste of electron beam and power can be eliminated.

Next, the configuration of the sterilization chamber 25 provided with the electron beam irradiation device 30 of the present embodiment will be described. As shown in FIG. 5, the sterilization chamber 25 is surrounded by a shielding wall 22 made of concrete or the like so that X-rays generated during electron beam irradiation do not leak outside. In addition, a conveyor for conveying the irradiation target 11 along the shielding wall 22 is provided. The conveyor includes a roller conveyor 12, a skew conveyor 13, an irradiation conveyor 1 from the entrance 26 side to the exit 27 side.
4. Rollers 12 are arranged in this order. Also,
Downstream of the inlet roller conveyor 12, a stopper 17 operated by compressed air is provided. The stopper 17 is not limited to a pneumatic stopper, but it is preferable to employ a stopper that operates with compressed air in consideration of the influence of X-rays.

Further, an electron beam accelerator 10 is provided above a predetermined position of the irradiation conveyor 14, and can irradiate an electron beam when the object 11 passes through the electron beam irradiation area to perform a sterilization process. It is configured as follows. At this time, the electron beam accelerator 10 may be arranged on the side wall of the irradiation conveyor 14 so as to irradiate the side surface of the irradiation target 11 with the electron beam. If is not enough, another electron beam accelerator may be provided on the side facing the electron beam accelerator 10. In the central part of the sterilization chamber 25 in the present embodiment, there is a central shielding wall 21 made of concrete or the like, like the outer wall. The central shielding wall 21 is formed so that X-rays generated from the electron beam irradiation area do not directly hit the stopper 17 and has a purpose of preventing the stopper 17 from being deteriorated.

In the electron beam irradiation apparatus 30, the flow of the transport system is as follows. First, the sterilization room 25
The irradiation object 11 is carried in by the roller conveyer 12 through the entrance 26 of the roller, and the irradiation object is stopped for a predetermined time by the stopper 17 located on the exit side of the roller conveyer 12. The stopper 17 is released when a predetermined time has elapsed, and the irradiation target 11 is transferred to the skew conveyor 13. Here, the irradiation object 11 which is conveyed in a close contact state or with the distance between the irradiation objects narrowed to some extent is aligned in a predetermined direction by the action of skew, and is fed to the irradiation conveyor 14 of the next stage. . The irradiated object 11 that has been brought into close contact with the irradiation conveyor 14 due to the speed difference between the irradiation conveyor 14 and the skew conveyor 13 is sterilized by a high-energy electron beam emitted from an electron beam accelerator 10 installed in the middle of the irradiation conveyor 14. After being applied, the roller conveyor 1 provided in the subsequent stage
2 to the exit side. As described above, the electron beam irradiation apparatus according to the present embodiment can easily and continuously perform the electron beam irradiation processing, and performs the sterilization processing with low electron beam and power loss and high processing efficiency per unit time. be able to.

[0021]

As described above, according to the present invention, an object to be irradiated conveyed in an electron beam irradiation area is passed in a state of being in close contact with the object to irradiate the space between the objects with the electron beam. Such useless consumption of electron beams and power can be reduced. In addition, by performing the electron beam irradiation while aligning the irradiation object in a predetermined direction, unnecessary irradiation of the electron beam is eliminated, the electron beam irradiation density is increased, the processing time can be reduced, and the productivity is reduced. improves. Further, by providing a shielding wall made of concrete or the like at the center of the sterilization chamber provided with the electron beam irradiation device and providing a stopper behind the shielding wall, deterioration of the material of the stopper due to X-rays or the like can be reduced.

[Brief description of the drawings]

FIG. 1A is a partial configuration diagram illustrating an electron beam irradiation region according to the present embodiment, and FIG. 1B is a partial configuration diagram illustrating a conventional electron beam irradiation region.

FIG. 2 is a side view showing close contact conveyance of the electron beam irradiation apparatus according to the present invention.

3A is a schematic cross-sectional view in the direction of arrows AA in FIG. 1, and FIG. 3B is a schematic cross-sectional view in the direction of arrows BB in FIG.

FIG. 4 is a side view showing the one-sided conveyance of the electron beam irradiation apparatus according to the present invention.

FIG. 5 is a schematic configuration diagram of an electron beam irradiation apparatus according to the present embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Electron beam accelerator 11 Irradiated object 12 Roller conveyor 13 Skew conveyor 14 Irradiation conveyor 15 Beam stop 16 Fixed guide rail 17 Stopper 20 Electron beam 25 Sterilization room 30 Electron beam irradiation device

Continued on the front page (51) Int.Cl. ⁷ Identification FI FI Theme Court II (Reference) G21K 5/04 G21K 5/04 E

Claims (8)

[Claims] 1. An electron beam irradiation apparatus for irradiating an electron beam while conveying a three-dimensional irradiated object in a predetermined direction to achieve an intended purpose such as sterilization. Transport process,
A second transporting step located on the downstream side thereof to closely transport the object to be irradiated, and irradiating the object to be irradiated with an electron beam in the second transporting step. 2. The speed of the first transporting step is increased, the speed of the second transporting step is reduced, and the object to be irradiated is temporarily stopped at least at the exit side of the first transporting step. 2. The electron beam irradiation method according to claim 1, further comprising a stopping means for stopping the electron beam irradiation. 3. A method according to claim 1, further comprising a third transporting step having a biasing means for biasing and aligning the irradiation object in a predetermined direction between the first transporting step and the second transporting step. The electron beam irradiation method according to claim 1. 4. An electron beam irradiation apparatus for irradiating an electron beam while transporting a three-dimensional object in a predetermined direction to achieve an intended purpose such as sterilization. Transportation means,
A second transporting means which is located at a lower speed downstream of the first transporting means and closely transports the object to be irradiated, and which is located between the two transporting means and aligns the object to be irradiated in a predetermined direction; A third transporting means provided with a biasing means for causing the light to irradiate an electron beam, and a stopper means provided at least on an exit side of the first transporting means for temporarily stopping an object to be irradiated. An electron beam irradiation apparatus, wherein an electron beam accelerator is disposed so as to face the second transport means. 5. A control means for controlling a speed of each of said transport means and a cut-out interval of an irradiated object by a stopper means so that an object to be irradiated is closely transported by said second transport means. The electron beam irradiation apparatus according to claim 4, wherein: 6. The electron beam irradiation apparatus according to claim 4, wherein a predetermined linear distance is provided near a start end of said third transport means. 7. A system according to claim 1, wherein a shielding wall is provided between said stopper means and said electron beam irradiation area so that X-rays generated from said electron beam irradiation area do not directly hit said stopper means. Item 5. An electron beam irradiation apparatus according to Item 4. 8. An electron beam irradiation apparatus according to claim 4, wherein said stopper means is operated by compressed air.