JP2003153987A - Electron beam irradiation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a system for effectively sterilizing the mails (including home delivery mails) enclosing powdery materials which may include anthrax without requiring irradiation of electron beams to all the mails, in which an electron beam scanning part can be easily carried in/out when the electron beam scanning part is set or maintained. SOLUTION: The device has a screen board 13 mounted on a carry conveyor 12 for carrying an irradiated article for preventing transmission of the radiation generated from the electron irradiation except to a sterilization chamber, and electron beam scanning parts 10A and 10B for irradiating electron beams from both sides to the irradiated article. The carry conveyor line, especially passing inside the sterilization chamber surrounded by screen walls, is extended outside the screen walls, and carry-in/out parts of the irradiated article are disposed on the extended carry conveyor line. In addition, a means for discriminating mail which may included anthrax by discriminating a suspicious sender or address of the mail or the contents enclosed in the mail, is mounted on a transfer line for transferring the mail to the carry-in part on the extended line. Accordingly, only the mail which may include anthrax discriminated by the discrimination means is transferred to the carry-in part on the conveyor, where the mail is sterilized with the irradiated electron beams.

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 for irradiating an electron beam to medical instruments, food and drink containers, and mail items containing anthrax to achieve initial purposes such as sterilization. In particular, the present invention relates to an electron beam irradiation apparatus capable of irradiating and sterilizing an irradiation object with a single line.

[0002]

2. Description of the Related Art Products such as medical instruments and food and drink containers are required to be sufficiently sterilized for shipping as products. Although various methods are used for these sterilization methods, among them, the electron beam irradiation sterilization method is popular because of advantages such as short processing time, continuous processing, and high penetrating power.

An electron beam irradiation apparatus used in such an electron beam irradiation sterilization method includes an electron beam accelerator system for generating an electron beam to irradiate an irradiation object, a conveyor for conveying the irradiation object to an electron beam irradiation area, and the like. And a radiation shielding system such as a shielding wall for preventing leakage of radiation generated by the electron beam irradiation to the outside.

On the other hand, medical devices called artificial organs such as artificial dialysis devices and artificial lungs made of hollow fibers have a three-dimensional and complicated shape. For this reason, the difference in the areal density of each part is large, and the dose distribution (ratio between the maximum dose and the minimum dose) in one product during electron beam irradiation is large. The larger the value, the greater the safety and product management. There was a problem with the performance. Therefore, in order to suppress the variation in dose distribution due to irradiation, a double-sided irradiation method in which electron beams are irradiated from both the front and back sides is necessary.

FIG. 6 shows a schematic horizontal sectional view of a conventional double-sided irradiation type electron beam irradiation apparatus disclosed in Japanese Patent Laid-Open No. 2000-14750. The apparatus includes a conveyor mechanism including a forward conveyor 51a, a backward conveyor 51b, and a return conveyor 51c in the chamber to be sterilized 50, and the forward conveyor 51.
a, electron beam accelerators 53a and 53b provided in the middle of the return conveyor 51b, a reversing mechanism 52 provided to the return conveyor 51c, and maintenance passages 54a and 54b
And a central shielding wall 55 located in the central part of the sterilization chamber 50.
Composed of and. In this way, maintenance work can be easily performed by providing the maintenance passages 54a and 54b in the sterilization chamber 50 along the conveyor and by sufficiently providing the storage chambers of the electron beam accelerators 53a and 53b.

However, as described above, the conventional electron beam irradiation apparatus needs to be reflected and deflected twice or more in order to prevent the radiation generated by the electron beam irradiation from leaking to the outside, and the inside of the shielding wall has a maze structure. Not only
Even if a peripheral circuit by the conveyor is provided, it is necessary to provide a reversing mechanism between the electron beam accelerators 53a and 53b, and as a result, not only the conveyor peripheral circuit becomes unnecessarily long,
Since the entire circumference of the conveyor circuit is covered with the shielding wall, the size of the entire apparatus is increased. As a result, it is difficult to install the electrophotographic irradiation device on an existing production line, and it is not possible to easily respond to changes in the layout of the factory.

On the other hand, in US Pat. No. 6,191,424,
A miniaturized in-line type electron beam irradiation apparatus that can be easily installed on a production line has been proposed. FIG. 6 shows an electron beam irradiation apparatus in such an invention. The configuration of the electron beam irradiation apparatus is such that a first shielding means 018 made of concrete or the like, an electron beam irradiation apparatus 019 installed in the space 021 of the first shielding means 018, and a conveyor system for conveying an irradiation object. 020, a transport path 022 provided in the first shielding means, and a container 0 on which an irradiation target object is placed.
23, and a truck 024 on which the container is transported.

[0008] The container 023 conveys the object to be irradiated and has a wall in front of and behind it to have a function of preventing scattering of radiation as a second shielding means. Further, the electron beam irradiation device installation space and the conveyor system installation space are set to a minimum size so that the radiation does not leak to the outside through the gap between the space and the container 023.

[0009]

However, since the invention described in US Pat. No. 6,191,424 is one-sided irradiation and not two-sided irradiation, it cannot cope with a three-dimensionally complicated shape of a medical device or the like. However, in the above-mentioned device, there is a problem that the working space is not sufficiently secured and that it takes a very long time to recover when a problem occurs in the device body. Further, since the prior art is single-sided irradiation from the conveyor top surface, the conveyor is directly irradiated with an electron beam,
It has a drawback that the conveyor is deteriorated and activated.

In recent years, following the terrorist attack on buildings on September 11, 2001 in the United States, the so-called biological terrorism problem of postal matter (including parcel delivery) encapsulating powdery substances containing anthrax has occurred. There is. The present invention is also effective for such sterilization of B. anthracis. However, irradiating all the postal items with an electron beam requires an expensive electron beam irradiating device, and constructing a system for sterilizing a large amount of postal items not only in terms of cost but also in terms of space. It is impossible.

In view of the problems of the prior art, the present invention has three-dimensional objects to be irradiated such as medical devices and foods having a high areal density, and mails containing powdered substances containing anthrax, or a plurality of three-dimensional objects to be irradiated. 1 in a storage box such as a cardboard box containing
When sterilizing by irradiating with high energy electron beam of -10 MeV, it is possible to reduce the size of the device and perform double-sided irradiation, and further, to easily integrate the electron beam irradiation device into an existing production line (system) ) Is intended to provide. Further, an object of the present invention is to prevent leakage of an electron beam to the outside and deterioration or destruction of the electron beam irradiation device when a double-sided irradiation type sterilizer is constructed by irradiating a high energy electron beam of 1 to 10 MeV. An object of the present invention is to provide an electron beam irradiation device.

Another object of the present invention is to effectively sterilize postal items (including parcels) enclosing powdery substances that may contain anthrax bacteria, without irradiating all postal items with electron beams. Is to build a system that does.

[0013]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention provides an electron beam scanning unit including a scanning horn that irradiates an object to be irradiated carried on a conveyor with an electron beam to sterilize the object. Is an electron beam irradiation apparatus provided in a sterilization chamber surrounded by a shielding wall, wherein the conveyor is formed into an endless circular shape (elliptical circular space) including two straight lines, and The two concave section storage spaces having the above-mentioned positional difference on the straight line are formed to face each other to form an electron beam double-sided irradiation unit (this part is a shield wall structure), and the irradiation target is carried in and carried out on the other straight line. It is characterized by having a section.

As a result, only the electron beam both-side irradiation portion can be formed as a shield wall structure, the other portion can be formed in the open region, and the loading and unloading portion of the irradiated object is formed in the straight line on the other side. In addition, since the loading and unloading part of the irradiated object, which can be efficiently formed by flow work, and which needs to be manned especially when formed in an oval shape, is located on the back side of the shielding wall structure, It is safe without being irradiated with electron beams.

In this case, it is preferable that the object to be irradiated carried on the conveyor be irradiated with a position difference from the lateral direction. That is, in the case of double-sided irradiation, if two electron beam scanning units are arranged face-to-face with the conveyor in between, the electron beams from the other side scanning units are irradiated with each other, and the respective electron beam scanning units are destroyed. In the invention, it is avoided that the conveyor is directly irradiated with an electron beam, and the degree of deterioration and activation of the conveyor is significantly reduced, and forming recessed spaces on both the left and right sides of the conveyor is described later in the embodiment. As shown in the figure, the electron beam scanning unit is placed on the gantry, and the mobility during maintenance and inspection becomes easy.

According to a second aspect of the present invention, the position is provided between the two recess storage spaces, together with the inlet side and the outlet side of the electron beam irradiation area of the conveyor facing the two recess storage spaces having the position difference. A shielding wall is arranged in the conveyor carrying space, and the irradiation wall is formed only on one straight line portion of the conveyor that surrounds the electron beam double-side irradiation unit. In this case, the shielding wall may be fixed, or may be formed on the conveyer or on both sides of the tray.

That is, when the electron beam scanning units are arranged close to each other across the conveyor, the electron beam is reflected in the conveyor transportation space and hits the scanning unit on the other side, causing deterioration or destruction of the electron beam scanning unit. There is a fear. Further, in order to prevent the electron beam leakage, a maze structure for deflecting the conveyor transportation space facing the recessed space two or more times is required, and the size is inevitable. Therefore, as described above, by disposing the shield wall on the conveyor transfer space located between the two recess storage spaces, only the electron beam irradiation area is used as the shield space and other conveyor transfer areas are opened. The radiation generated by electron beam irradiation can be configured not to leak outside. In other words, only a limited area surrounding the electron beam scanning unit including the scanning horn that irradiates the electron beam for sterilization may be configured with the shield wall structure.
Even when sterilizing by irradiating with a high-energy electron beam of 0 MeV, the electron beam scanning is performed on both sides of the conveyor while sandwiching the conveyor, while miniaturizing the entire device system including the shield wall structure. Even when the parts are arranged close to each other, it is possible to eliminate the risk that the electron beam will be reflected in the conveyor transport space and hit the scanning unit on the other side, and the deterioration or destruction of the electron beam scanning unit on the other side can be eliminated. .

Further, since double-sided irradiation is possible and the shield wall structure can be downsized, it is easy to incorporate the electron beam irradiation system using an existing production line (of a sterilization system other than the electron beam irradiation system). Become. In particular, the electron beam scanning unit is movably formed, and a shield wall located between the electron beam scanning unit and the outside of the sterilization chamber is made movable, and the electron beam scanning unit is opened by opening the movable wall. If it can be moved to the outside, the electron beam scanning unit can be easily pulled out to the outside of the sterilization room to perform work, and the work efficiency can be improved. Since it is not necessary to provide it, the electron beam irradiation apparatus can be further downsized. That is, an electron beam irradiation apparatus for preventing radiation scattering by providing a shielding means such as a shielding plate made of lead, iron or the like so as to divide the space inside the shielding wall where the conveyor is disposed into a plane substantially perpendicular to the traveling direction. Since it is difficult to provide a working space in the sterilization chamber from the above configuration, the electron beam scanning unit can be easily taken out of the sterilization chamber to facilitate maintenance of the miniaturized electron beam irradiation apparatus. There is.

Further, in the apparatus according to the present invention, wherein the irradiation object is a postal matter containing anthrax, a suspected sender, addressee or mail is provided upstream of the irradiation object passing section of the carry-in section of the other straight line. A means for discriminating a postal matter (including a delivery product) that may contain anthrax bacteria by identifying the inclusion in the article is provided, and only the postal matter that may contain the anthrax bacteria discriminated by the discriminating means is provided on the conveyor. It is preferable to transfer to the upper carrying-in section and sterilize the anthrax by electron beam irradiation.

That is, to explain in a broader concept, mail items (including parcels) containing anthrax that are carried on a conveyor.
An electron beam irradiation device for irradiating an electron beam to a sterilization process, wherein a conveyor line passing through a sterilization chamber surrounded by a shielding wall is extended outside the shielding wall, and the extended conveyor line is covered. Identification of the suspicious sender, addressee, or inclusions in the postal matter on the transfer line that transfers the postal matter to the carry-in section of the extended extension line while providing the carry-in and carry-out section for the irradiated matter By providing means for discriminating the postal matter that may contain anthrax by means of the electron beam irradiation, only the postal matter that may contain the anthrax is discriminated by the discrimination means is transferred to the carry-in section on the conveyor. It is characterized in that it is configured to perform sterilization.

Here, in the closest case, for example, the suspicious sender may be a "postal with sender in A city in Florida", and may be irradiated with an electron beam. Alternatively, unspecified mail items other than the safe specified sender registered by the postal delivery office may be identified. (It is easy if you use a database that a courier, etc. have.) Also, the suspicious address is, for example, a mass media address such as a newspaper company or a TV station, or a postal address that is addressed by the Prime Minister or Foreign Minister. The object may be discriminated and the electron beam may be irradiated. Examples of means for discriminating a postal matter that may contain anthrax bacteria by identifying the enclosed matter in the postal matter include a hydrometer, an X-ray detector, and the like for discriminating that the enclosed matter is a powder. According to this invention,
Effectively without irradiating all mail with electron beam,
It is possible to construct a system for sterilizing mail items (including home delivery items) in which powdery substances that may contain anthrax bacteria are enclosed.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be exemplarily described in detail below with reference to the drawings. However, the dimensions, materials, shapes, relative positions, etc. of the components described in this embodiment are not intended to limit the scope of the present invention thereto unless specifically stated otherwise, and are merely illustrative examples. Not too much. In the present embodiment, the electron beam scanning unit can be used from a large machine having an acceleration energy of 10 MeV to a small machine having an acceleration energy of 1 MeV, and is selected according to the installation area, the type of object to be irradiated, the size, and the like. Further, in the present embodiment, the irradiated object to be sterilized is a surgical gown, a medical instrument such as an infusion bag, a beverage container such as a PET bottle, and a postal matter enclosing a powdery substance that may contain anthrax ( (Including home delivery) is not particularly limited,
In the process of continuous processing, not only the above-mentioned mail, but also various types of products such as medical tools and beverage containers may be mixed and mixed.

FIG. 1 is a plan view showing the overall configuration of a system including an electron beam irradiation apparatus according to an embodiment of the present invention.
2 is a plan view of the electron beam irradiation apparatus according to the first embodiment of the present invention, and FIG. 3 is a side view of the electron beam irradiation apparatus according to the present embodiment. First, an overall system configuration of the present embodiment for sterilizing a mail (including a parcel delivery product) in which a powdery matter that may mainly contain anthrax is enclosed is described from the plan view shown in FIG. Such an electron beam irradiation device,
A carry-in belt conveyor 25A and a discharge belt conveyor 25B, which are linearly arranged along one straight path 12B of the conveyer conveyor, which will be described later, for carrying in and discharging the irradiation object such as the postal matter, and a conveyer conveyor to be described later. 1 straight road 1
2B, a loading / unloading means including a pusher 27 and a puller 26, and the belt conveyor 25 to irradiate the object 3 to be irradiated.
In order to transfer 0 and transfer it through the irradiation area, an oval circular circuit is formed in an endless manner, and the transfer system is composed of a transfer conveyor 12 having two straight paths in parallel. An irradiation system consisting of a pair of electron beam scanning units 10A, 10B arranged on a straight line, a shielding wall 14 for preventing leakage of radiation so as to surround the electron beam scanning units 10A, 10B and the straight line portion of the conveyor 12. And a shielding system consisting of the movable wall 15.

In the transport system, means 50 for identifying a postal matter which may contain anthrax on the upstream side of the carry-in belt conveyor 25A by identifying a suspicious sender, addressee or inclusion in the postal matter. Is provided, and only the postal matter that is likely to contain anthrax is discriminated by the discriminating means 50 is passed to the downstream side of the carry-in belt conveyor 25A, and the postal matter is directly subjected to 31B, 31C or a box shape described later. It is thrown into the tray 31A (see FIG. 4) and made to flow to the downstream side of the carry-in belt conveyor 25A, and other postal matter is returned to the discharge belt conveyor 25B through the detour conveyor 60 and is provided downstream of the carry-in belt conveyor 25A. only by pusher 27 for flowing ones (mailpieces that may include anthrax) was transferred to the carry portion 12B ₁ of the conveyor 12 It is configured to perform sterilization by electron beam irradiation.

Here, the means 50 for discriminating the suspected sender may be an image recognition device such as a bar code or an OCR. For example, as shown in FIG. 5 (A), a mail item or the like which may contain anthrax. Since the irradiation object 30 is "A city in Florida, the postmark of the municipality that does not match the sender's address is stamped", etc., the postmark and the sender's address are read by an image recognition device such as OCR. (S1), after the read data is compared with the database (S3) by the computer (S2), the postal matter that may contain anthrax and the other postal matter are classified (S4) to include anthrax. The postal items that may be afraid are sent to the downstream side of the carry-in belt conveyor 25, and the other postal items are returned to the discharge belt conveyor 25B via the detour conveyor 60.

Further, without adopting the above configuration, for example, as shown in FIG.
As shown in (A), the safe specified sender registered by the recipient or the post office is registered in the database (S3), and the computer (S2) compares the unspecified mail with the database. You may decide. Further, in the case of distinguishing from the destination, for example, the description such as “personal address”, “confidential”, “Personal”, “Confidential”, etc. that limits the number of people, the destination of mass media such as newspaper companies or TV stations, or Database of destinations such as Prime Minister and Foreign Minister in advance (S3)
If the address read by the image recognition device (S1) such as OCR is a corresponding mail item according to the judgment of the computer (S2), the mail is collected and the mail item is directly or in a box-shaped container. It is also possible to carry out the input sorting processing (S4) and to make it flow to the downstream side of the carry-in belt conveyor 25A.
The sender and the destination may be identified by reading an image with the image recognition device (S1), but such identification is carried out in advance in the case of air freight or home delivery by these companies. However, this database may be used for identification.

As a means for discriminating the postal matter which may contain anthrax by identifying the inclusions in the postal matter, FIG.
As shown in (B), the image recognition means for recognizing that foreign matter such as white powder is leaking from the surface of the mail, the odor detector for detecting an offensive odor, for example, the inclusion is a powder. After using a specific gravity meter and an X-ray detector, etc. (S5), mail that may contain anthrax and mail other than that are sorted (S4) and mail that may contain anthrax Items are sent to the downstream side of the carry-in belt conveyor 25A, and other mail items are returned to the discharge belt conveyor 25B via the detour conveyor 60.

Returning to FIG. 1, the irradiation object 30 such as a postal matter which may contain anthrax is transferred to the elliptical track type conveyor 12 by the pusher 27. The elliptical transfer conveyor 12 circulates the irradiation object 30 and is sterilized by the electron beam irradiation devices 10A and 10B provided in one straight path portion of the transfer conveyor 12. On the conveyor 12, a large number of shielding plates 13 as shielding means are arranged upright in accordance with the tray mounting intervals. The shielding plate 13 is formed of a material having a low radiation transmitting power such as lead and iron, and has a function of preventing leakage of radiation in the shielding wall 14 in the conveyor passage direction.

The shield wall, which functions as an electron beam irradiation unit area, is provided with a recessed space for accommodating an electron beam scanning unit on both sides of the conveyor, sandwiching the conveyor by shifting the position along the flow direction of the straight path of the conveyor. It is formed by opening the side of the wall facing the conveyor, and the electron beam scanning units are housed in the two recessed spaces, respectively, so that there is a positional difference from the lateral direction of the irradiation target transported on the conveyor. It can be irradiated. Now, FIG. 2 shows a main structure of the electron beam irradiation area. 10A and 10B are electron beam scanning units that irradiate an irradiation object with an electron beam to perform sterilization treatment, and 11 is a pedestal on which the electron beam scanning unit is mounted, and a movable means such as casters is provided under the gantry. The electron beam scanning unit 11 is movable. Reference numeral 12 denotes a conveyer that conveys an object to be irradiated, and shield plates 13 are erected at regular intervals. The shielding plate 13
It is preferable to use a material having a low radiation transmittance, such as lead or iron, at this time, the shield plate 13 is set to the position by the second shield wall that is erected at a predetermined interval on the conveyor. The shielding plate should be positioned on the conveyor transport space located between the two recess storage spaces, together with the inlet side and the exit side of the electron beam irradiation area of the conveyor facing the two recess storage spaces having a difference. Set the interval to.

The electron beam scanning units 10A and 10B housed in the recessed space are mounted and fixed on a gantry 11 with casters, and the rear side surface of the movable wall 15 is fixed. A moving means such as casters is also installed on the movable wall 15, and the movable wall 15 and the pedestal 11 are integrated.
The electron beam scanning unit 11 placed on the is configured to be easily pulled out from the sterilization chamber. In addition, in FIG.
The side shows an open state and the B side shows a closed state.

The electron beam scanning units 10A and 10B mounted on the gantry 11 and the conveyor 12, which will be described in detail later with reference to FIG. 3, are surrounded by a shielding wall 14 having a shielding effect such as concrete. . The shielding wall 14 is arranged such that the recessed space in which the electron beam scanning units 10A and 10B are installed is displaced along the flow direction of the straight path of the conveyor to sandwich the conveyor, and the electron beam scanning units 10A and 10B are housed on both sides thereof. The recessed spaces 140 and 141 are formed by opening the side of the irradiation wall facing the conveyor. Further, the movable wall 15 at the opening / closing portion of the shield wall 14 which is located on the back side of the recessed space in which the electron beam scanning unit is housed and which is configured to open / close the shield wall with the outside is the same as in the present embodiment. Stand 11
It is configured integrally with the pedestal 11 so that it can be opened and closed integrally in synchronization with the movement of the gantry 11, but it is a type that opens and closes in a lateral direction in a sliding manner, a type that the movable wall 15 is a door that opens on one side, ,
There is no particular limitation as long as it can form an opening through which the electron beam scanning units 10A and 10B can be loaded and unloaded. The movable wall 15 may be made of a material different from that of the shielding wall. For example, when heavy metal such as lead or iron is used, the wall thickness of the movable wall 15 can be made smaller than that of concrete often used for the shielding wall portion. Because it is possible, it is easy to move the movable wall part.

In the embodiment shown in FIG. 2, the electron beam irradiation devices 10A and 10BA positioned on the A side as described above.
Shows the open state of the movable wall 15 and shows the closed state of the electron beam irradiation device 10B located on the B side. The movable wall 15 is provided with a sensor so that the movable wall 15 is When the side is open, the electron beam scanning units 10A, 10B
Should not work. In addition, the movable wall 15
The joint surface between the shield wall 14 and the shielding wall 14 has a rectangular structure with an L-shaped step portion to prevent radiation from leaking to the outside of the sterilization room.

The configuration of the electron beam scanning units 10A and 10B will be briefly described with reference to the side view of FIG. The electron beam scanning unit, together with the klystron 22 and the electron gun 29, the accelerating unit 20 that accelerates the high-voltage pulse by the accelerating tube unit,
The electron beam irradiation horn 21 deflects and scans the accelerated high-frequency electron beam generated by the accelerating unit 20 to scan and irradiate the irradiation target. The accelerated electron beam is converged by a converging electromagnet (not shown) to reduce the diameter. It is introduced into the irradiation horn 21 in the shape of a flat truncated pyramid while holding the energy thus densified. The irradiation horn 21 is configured to be changed and scanned by a scanning electromagnet provided on the entrance side and perform electron beam irradiation at a dose suitable for an object to be irradiated. In the present embodiment, the klystron 22 and the high voltage power source 23 for driving the electron gun are integrally housed in the recessed space, but the words electron beam scanning units 10A and 10B are limited to the klystron. This is because the high voltage power supply 23 for driving the electron gun 22 and the electron gun may not necessarily be housed in the same recessed space, but may be arranged outside the shielding wall area or in another space inside the area.

In this electron beam irradiation apparatus, the rear end of the gantry 11 having casters 17 at the bottom and the movable wall 15 are fixedly provided, and are movable integrally.

The shield plate 13 used for the second shield means may be provided upright on the front side and the rear side of the irradiation target tray in the transport direction as shown in FIG. FIG. 4 shows a cross-sectional view of a transportation facility including the irradiation system part. In FIG. 4, a shield wall 14 formed of a shield material such as concrete is provided with a recessed space as a storage space for the electron beam scanning unit at a position indicated by a dotted line, and is used for disposing the conveyor 12. Although the transport passage 19 penetrates straightly, the second shield wall of the tray placed upright on the conveyor and erected conveys the transport passage 19 into two recessed storage spaces having the position difference. With the entrance side and exit side of the electron beam irradiation area of the facing conveyor,
The interval is set so that the shielding plate is located on the conveyor transport space located between the two recess storage spaces.

On the transfer conveyor 12, a plurality of trays 31A, 31B, 3 on which the objects 30 to be irradiated are placed.
1C is conveyed in the direction of the arrow in FIG. As in the present embodiment, in the in-line type electron beam irradiation apparatus connected to another manufacturing process, a postal product (including a parcel delivery product) in which a powdery substance that may contain anthrax is to be sterilized is enclosed. In some cases, a certain irradiation target object 30 has various shapes. Therefore, in the present embodiment, the irradiation target object is classified according to the size of a postal matter (including a parcel delivery product) containing a powdery substance that may contain anthrax. 31A, 31B, 31 provided with different fixing means for each type of
Even if each type having a different shape is mounted on the tray by using C, the structure is such that stable irradiation can be performed. It should be noted that the current amount control means, or the transfer speed control means or the like is provided on the transfer conveyor 12, so that the irradiation target 30
It is preferable to appropriately adjust the energy value and irradiation dose of the electron beam depending on the type and size of the. In the transport trays 31A, 31B, 31C, the shielding plates 13 made of lead, iron or the like are arranged in the front and rear portions thereof, and the bottom portions thereof are the shielding plates 13 '.
Similar to the above, it is formed of a plate of a material that is hard to be activated. The shielding plate 13 ′ needs to have a wall thickness that does not allow the radiation to pass therethrough in order to prevent the radiation from being scattered. However, it is not necessary to prevent the radiation from passing through in the vertical direction. It should be thick enough to sag.

The shield plate 13 'is provided with a support 16 for fixing a tray in which large mail pieces, small envelopes, etc. are stored.

[0038]

As described above, according to the present invention, direct irradiation of the conveyor with an electron beam can be avoided, and the degree of deterioration and activation of the conveyor can be significantly reduced.
Forming the recessed spaces on both the left and right sides of the conveyor also facilitates the mobility during maintenance and inspection by placing the electron beam scanning unit on the pedestal, as will be described in the embodiment below.

Further, according to the present invention, only a limited area surrounding the electron beam scanning portion including the scanning horn which irradiates the electron beam for sterilization may be constituted by the shield wall structure, whereby 1 to 10 MeV is provided. Even when sterilizing by irradiating with high-energy electron beam, the electron beam scanning unit is provided on both sides of the conveyor while sandwiching the conveyor while attempting to downsize the entire apparatus system including the shield wall structure. Even when they are arranged close to each other, it is possible to eliminate the risk that the electron beam may be reflected in the conveyer transport space and hit the scanning unit on the other side, and the electron beam scanning unit on the other side may be deteriorated or destroyed. Further, since double-sided irradiation is possible and the shield wall structure can be downsized, it becomes easy to incorporate the electron beam irradiation system by using an existing production line (of a sterilization system other than the electron beam irradiation system).

In particular, since only the electron beam double-sided irradiation portion is formed as a shield wall structure, the other portion can be formed in the open region, and the loading and unloading portion of the irradiated object is formed in the straight line on the other side. In addition, since the loading and unloading part of the irradiated object, which can be efficiently formed by the flow work and needs to be manned especially when it is formed in an oval shape, is located on the back side of the shield wall structure, It is safe without being irradiated with electron beams.

Further, according to the third and fourth aspects of the present invention, all mail items are effectively enclosed without irradiating the electron beam with a powdery substance which may contain anthrax bacteria (delivery items). In the current situation where the fear of bioterrorism caused by B. anthracis is growing in the entire civilized society because it is possible to construct a system for sterilizing ()), the benefit to humanity is immeasurable.

[Brief description of drawings]

FIG. 1 is a plan view showing an overall configuration of a system including an electron beam irradiation device according to an embodiment of the present invention.

FIG. 2 is a plan view of a shield wall structure showing an electron beam scanning unit and a recess space according to the first embodiment of the present invention.

FIG. 3 is a side view of the electron beam irradiation apparatus according to the embodiment of FIG.

FIG. 4 is a cross-sectional view showing a shield wall structure of an electron beam irradiation device according to a second embodiment of the present invention.

FIG. 5 (A) shows a procedure for determining a suspicious sender or address, and FIG. 5 (B) shows a procedure for determining a postal matter which may contain anthrax by identifying inclusions in the postal matter. It is a block diagram.

FIG. 6 is a side view of an electron beam irradiation device having a labyrinth structure according to a conventional technique.

FIG. 7 is a plan view of an in-line type electron beam irradiation apparatus in the related art.

[Explanation of symbols]

10A, 10B Electron beam scanning unit 11 stand 12 irradiation conveyor 13 Shield 14 Shielding wall 15 Movable wall 17 casters 20 electron beam accelerator 21 Electron beam irradiation unit 30 irradiation target

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Takashi Yamakawa             10 Oemachi, Minato-ku, Nagoya-shi Mitsubishi Heavy Industries Ltd.             Ceremony Company Nagoya Aerospace Systems Works (72) Inventor Yuichiro Kano             10 Oemachi, Minato-ku, Nagoya-shi Mitsubishi Heavy Industries Ltd.             Ceremony Company Nagoya Aerospace Systems Works F-term (reference) 3F079 AA01 CA01 CA02 CA06 CB08                       CB29 CC05 DA12 DA21                 4C058 AA02 AA12 AA30 BB06 CC04                       KK03

Claims (4)

[Claims] 1. An electron beam irradiation unit provided in a sterilization chamber surrounded by a shielding wall, the electron beam scanning unit including a scanning horn for irradiating an object to be irradiated conveyed on a conveyor with an electron beam for sterilization. In the device, the conveyor is formed in an endless circular shape including two linear lines, and the two linear storage lines are made to face each other by accommodating the two recess storage spaces having the positional difference. An electron beam irradiation apparatus, which is formed and is provided with a carry-in and carry-out section of an irradiation object on a straight line on the other side. 2. The inlet side and the outlet side of the electron beam irradiation area of the conveyor facing the two recessed accommodation spaces having the above-mentioned difference in position, and the conveyor transportation space located between the two recessed accommodation spaces. 2. The electron beam irradiation apparatus according to claim 1, wherein a shield wall is arranged, and the irradiation wall is formed only on one straight line portion of the conveyor that surrounds the electron beam double-sided irradiation portion. 3. The apparatus according to claim 1, wherein the object to be irradiated is a postal matter containing anthrax, and a suspicious sender or addressee is provided on the upstream side of the object to be transferred part of the carry-in part of the other straight line. Alternatively, a means for discriminating postal items (including parcels) that may contain anthrax bacteria by identifying the inclusions in the postal items is provided, and only the postal items that may contain anthrax bacteria that are discriminated by the discriminating means are provided. The electron beam irradiation apparatus according to claim 1, wherein the electron beam irradiation apparatus is configured to be transferred to a carry-in section on the conveyor to sterilize anthrax by electron beam irradiation. 4. An electron beam irradiation device for irradiating a postal matter (including a home delivery) containing anthrax bacteria transported on a conveyor with an electron beam for sterilization, wherein the sterilization chamber is surrounded by a shielding wall. A conveyor line passing through the outside of the shielding wall, the conveyor line is provided with a carry-in and carry-out section for the irradiation object, and the postal matter is transferred to the carry-in section of the extended line. Provided on the transfer line to be placed is a means for discriminating mail items that may contain anthrax by identifying the suspicious sender, addressee or inclusions in the mail, and the anthrax bacteria discriminated by the discrimination means An electron beam irradiation apparatus, characterized in that only postal matters that may be included are transferred to a carry-in section on the conveyor and sterilized by electron beam irradiation.