JP2003000213A - Sterilization method for granular substance and granular substance sterilizer to be used for the method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a compact sterilizer for a granular body to be irradiated capable of uniformly and completely sterilizing the whole surface of the body to be irradiated and having high treatment speed and high reliability, and also to provide a method for completely sterilizing the granular irradiated body. SOLUTION: The method for efficiently sterilizing a granular body to be irradiated comprises thoroughly striking electron against the whole surface of the granular body passing through the inside of an irradiated body passage while rotating through an electron concentrate means in which electron emitted from a circular negative pole set in a vacuum vessel set surrounding the cylindrical irradiated body passage and kept in a high vacuum condition is accelerated between a circular positive pole and driven on a cone-like orbit, and then penetrated through a circular electron penetration window, and the penetrated electron is deflected from the all-round direction of the cylindrical irradiated body passage in a direction heading toward the inside of the cylindrical irradiated body passage.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention irradiates a granular object, particularly a grain, with relatively low energy electrons from the entire circumferential direction of a passage while moving it in the peripheral portion of a cylindrical passage. A method of sterilizing bacteria attached to the surface of a granular object by a thing, and a granular irradiation object sterilizer used for this, in particular, irradiating only the surface of the grain with a low-energy electron beam The present invention relates to a sterilizing method and a sterilizing apparatus in which the surface of a grain is more completely sterilized while an electron beam does not reach the inside of the grain to prevent the deterioration of quality, and the sterilization speed is increased.

[0002]

2. Description of the Related Art Among granular objects, those having a small particle diameter are treated as so-called powders, but they are still granular objects, and those having a particle diameter larger than the range of electrons are so-called granular particles. It can be treated as an object. Japanese Unexamined Patent Application Publication No. Hei 1-192362 discloses a device for sterilizing and sterilizing foods such as wheat flour and spices by holding a granular object as powder in a suspended state with a gas and irradiating it with radiation such as an electron beam. Has been done. Furthermore, Japanese Patent Laid-Open No. 8-522
No. 01 discloses a device in which a granular object as a powder is floated by a gas flowing from below in a powder transfer chamber, and in a fluidized state, the entire particle is uniformly irradiated with an electron beam to uniformly sterilize the particle. Has been done. In this device, there is a description to prevent sterilization effect unevenness due to an electron beam having a weak penetrating power, and it is suggested that the particles that have been levitated and fluidized move while rotating. In all of these cases, it is clear that the sterilization rate is low.

Further, Japanese Patent Laid-Open Publication No. 10-2157.
No. 65 uniformly sterilizes by irradiating the surface of the granular object, which is a grain, with a low-energy electron beam while rotating the granular object, which is a grain, by vibrating vertically and horizontally at the same time. A method of doing so is disclosed. The energy of the electron beam to be applied is 160 to 250 keV for brown rice, wheat, etc., and 200 to 250 keV for paddy, shelled buckwheat beans, etc. Microbes adhering to the surface of grains can be efficiently sterilized,
It is disclosed that the electron beam does not reach the inside of the grain and the quality of the grain is not deteriorated. It is clear that this method also has a low sterilization rate.

In Japanese Patent Laid-Open Publication No. 11-52100, an electron beam is formed by spreading a large number of granular objects in the form of thin films and dropping them, while flatly distributing energy of 200 keV or less from both sides thereof. An apparatus for sterilizing a granular material by irradiating with is disclosed. In this device, by spreading a large number of granular materials in a thin film and dropping them, it is possible to prevent the generation of shadows where the electron beam is not irradiated, and to distribute the electron beams evenly throughout the large number of granular materials. There is a description that it can be irradiated. There is also a description that it is preferable to drop the granular material in a single layer (in other words, one row) or in a state close thereto. This means that the width of the apparatus becomes large and the size of the entire apparatus becomes large when the processing capacity of the granular irradiation target is increased.

Japanese Laid-Open Patent Publication No. 11-101900
In the issue, there is an electron beam irradiation device with increased processing capacity by irradiating a low energy electron beam distributed in a plane while continuously transferring powder or granules with stirring by a screw conveyor in a casing. Proposed. In this method, the sterilization rate may be increased, but it is extremely difficult to completely sterilize the entire surface of each granular irradiation target with a low-energy electron beam, because the granular irradiation target overlaps. Is.

Japanese Patent Laid-Open Publication No. 11-109100
In the issue, grain-shaped objects to be irradiated, such as wheat, wheat, buckwheat, and spices before and after threshing, which are longer than spheres, are distributed in a plane while being moved by two conveyors arranged in two stages. A device for sterilizing by irradiating a low energy electron beam from above has been proposed. In this proposal, two conveyors are operated in opposite directions, and the same electron beam irradiating device is intended to irradiate a granular object to be irradiated twice with an electron beam. This is a painful measure to solve the problem that it is difficult to uniformly irradiate the entire surface of the irradiation target because the electron beam is irradiated from one direction, and it is possible to avoid the device from becoming complicated and large. Absent.

Japanese Patent Laid-Open Publication No. 2000-25448
In No. 6, foods such as tea leaves, rice, wheat, soybeans, adzuki beans, and other granular objects to be irradiated are floated by blowing gas from three directions, that is, upward, downward, and lateral in the transport path. A method of irradiating the granular irradiation target with a low-energy planar electron beam while being transported has been proposed. In this method, in order to float and transport the granular irradiation object, it is necessary to continuously and independently adjust the flow rate and flow velocity of the gas in three directions, which not only complicates the apparatus but also makes stable operation difficult. Therefore, it is difficult to continue uniform sterilization. Also, it is difficult to increase the processing speed.

Japanese Patent Laid-Open Publication No. 2000-30490
In No. 0, grains such as wheat, rice, beans, buckwheat, and pepper, and granules such as spices are conveyed by a vibrating conveyor that has unevenness on the vibration plate surface and is provided horizontally or inclined. There is proposed a method of irradiating a low-energy electron beam distributed in a plane while the granular object to be irradiated is being conveyed while being rotated. Not only is this device complicated, but it is difficult to increase the processing speed if the surfaces of these granular objects to be irradiated are to be irradiated completely and uniformly.

In any of the above-mentioned conventional examples, the treatment speed cannot be increased when the low energy electron beam is to be irradiated completely and uniformly over the entire surface of the granular object to be irradiated. When the speed is increased, there is a contradictory problem that uneven irradiation occurs. The cause is
This is because the electron beam irradiation device used conventionally only emits an electron beam distributed in a plane from one direction. In the present invention, an electron beam irradiation device capable of uniformly irradiating an electron beam from the circumferential direction has been developed, and by using this, a granular irradiation target that moves while forming a thin layer on the circumference and moving in the outer circumferential direction. The above-mentioned contradictory problems are solved by uniformly irradiating the electron beam from above.

Next, a conventionally used electron beam irradiation apparatus will be described. The conventional electron beam irradiation device is, for example,
As described in JP-A-11-19190, a linear metal filament is mounted in a fixed drum-shaped vacuum container, and the thermoelectrons emitted by heating by energizing the metal filament have a voltage of 500 KV or less. The electron beam is radiated to the irradiation target in the atmosphere by accelerating and passing through a flat plate-shaped electron transmission window made of a thin metal foil. FIG. 10 shows a schematic cross-sectional view of a conventional electron beam irradiation apparatus. In FIG. 10, 1001 is a vacuum container, 1003 is an electron gun structure, 1002 is a terminal for supporting the electron gun structure 1003,
Reference numeral 4 is a cathode filament, 1005 is a grid, and 1006 is an electron transmission window for transmitting electrons. The electrons emitted from the cathode filament 1004 are accelerated by the potential difference applied to the grid 1005, and further accelerated by the potential difference of 500 KV or less applied between the grid 1005 and the electron transmission window 1006 to pass through the electron transmission window 1006. The transmitted electron beam B01 is irradiated to the irradiation object 1011 which moves from the direction of arrow 1009 to the direction of arrow 1010 in the irradiation chamber. Since this device is large and the irradiation direction of the electron beam is constant, it is suitable for irradiating a sheet-shaped object to be irradiated with an electron beam, but it is not suitable for irradiating a granular object with an electron beam. Not suitable for. In the sterilizer for granular objects using this electron beam irradiation device, it is unavoidable that the above-mentioned problem of the two tradeoffs occurs. In addition, the electron transmissive window faces the surface of the granular irradiation object passage, and it is said that the electron transmissive window is damaged due to collision of the irradiation target object or flying of foreign matter contained in the irradiation target object, which is not reliable. There was a problem.

[0011]

The problem to be solved is to irradiate an electron beam uniformly over the entire surface of a granular irradiation target without degrading the inside of the irradiation target having a granular shape. To provide a method for sterilizing a granular object that can completely sterilize the entire surface of a granular irradiation target, has a high sterilization processing speed, is highly reliable, and does not require a wide installation space, and a granular object sterilizing apparatus used therefor. Is.

[0012]

According to the present invention, electrons emitted from a ring-shaped cathode provided in a vacuum container which is provided to surround a tubular passage to be irradiated and which is maintained in a high vacuum state are provided. The cylindrical irradiation passage is accelerated after being accelerated between the cylindrical irradiation passage and the annular anode having an electron passage hole provided around the irradiation passage, and the cylindrical irradiation passage is provided. Electrons that are transmitted through an annular electron transmission window that is provided to surround the and that deflect the transmitted electrons from the entire circumferential direction of the tubular irradiation passage to the inside of the cylindrical irradiation passage. By using the concentrating means and the irradiated object rotating means for moving the granular irradiated object while rotating in the cylindrical irradiated object passage, the granular object passing through the irradiated object passage while rotating The electrons are made to collide with the entire surface of the irradiated object, How to fully efficiently sterilize the entire surface of the irradiated body, it has proposed a sterilizing apparatus used therewith.

As one of the electron concentrating means, by using the magnet disposed coaxially with the cylindrical irradiation object passage, the magnetic flux density component parallel to the cylindrical irradiation object passage and the cylindrical shape can be obtained. A space having a magnetic flux density component toward the central axis of the irradiated body passage of is formed, electrons are caused to travel in this space, and the interaction between these magnetic flux density components and the electrons causes
As the vehicle travels, it receives a strong rotational force around the central axis of the cylindrical irradiation object passage and approaches the central axis of the cylindrical irradiation object passage.

The granular irradiation target is spirally moved in the cylindrical irradiation target passage by a rotary transfer device having a spiral irradiation target guide in the cylindrical irradiation target passage. It is moved vertically downward while moving to the surroundings, and around the axis contained in itself by the irradiated object rotating means that ejects the compressed gas at a high speed from a large number of gas ejection openings between the spiral object guides. It can be rotated at high speed. With such an irradiation object rotating means, the granular irradiation object can be moved vertically downward through the cylindrical irradiation object passage while rotating both on its own axis and on its revolution. Since the electron beam is uniformly irradiated from the outer circumference of the body passage, the surface of the granular irradiation target is uniformly processed by the low energy electron beam. Assuming that the surface layer of the irradiated body has a density of about 1 g / cm ³ , the irradiated electron beam has a density of about 0.
Since it does not enter deeper than 1 mm, it does not affect the inside of the irradiated body.

The electron transmissive window is provided so as to surround the irradiation object passage in a ring shape, and the surface of the electron transmission window has an angle with the outer surface of the irradiation object passage. It is difficult for the radiant heat emitted from the window to reach the irradiated body. Further, the electron transmissive window is invisible from the traveling direction of the irradiated object, and the fine particles contained in the irradiated object do not reach the electron transmissive window. Also,
There is an irradiation target partition as an irradiation target contact preventing means between the irradiation target passage and the electron transmission window so that the irradiation target cannot reach the electron transmission window. The irradiation target partition has slits or holes so that the electron beam can pass through them but the irradiation target and foreign substances contained therein cannot pass through. Further, when the irradiated body contains a fluid, a rotating body such as a fan having a slit is provided as the irradiated body contact preventing means to prevent the fluid from reaching the electron transmitting window.

According to a first aspect of the present invention, there is provided a method for sterilizing a granular object to be irradiated, in which the granular object to be irradiated is distributed in a peripheral portion in a tubular object passage. The method is characterized by irradiating the granular irradiation target with an electron beam from the entire outer peripheral direction of the cylindrical irradiation target passage while moving along the cylindrical irradiation target passage. By adopting the present invention, the granular irradiation object is thin and substantially evenly arranged over substantially the entire circumference of the tubular irradiation object passage, and electrons of low energy are simultaneously applied from the entire circumference direction in the aligned state. Since the rays are irradiated, the surface of the granular irradiation target can be uniformly sterilized at a high speed in a small space without the overlapping of the granular irradiation targets. Except for adopting an electron irradiation source that simultaneously irradiates an electron beam from the entire outer peripheral direction of the cylindrical irradiation target passage, the cylindrical irradiation target is much faster than the moving or rotating speed of the granular irradiation target. The same effect can be obtained by adopting a method of moving the electron irradiation source around the outside of the body passage, which is included in the present invention. Even when the movement of the irradiation target is stopped at the moment of irradiating the electron beam and the irradiation target is moved after the irradiation of the electron beam, the irradiation target is moved while moving the irradiation target from a macroscopic point of view. It is included in the present invention because it corresponds to irradiating a line.

According to a second aspect of the present invention, there is provided a method for sterilizing a granular object to be radiated, comprising the steps of:
In the method, the granular irradiation object spirally moves in the tubular irradiation object passage.
By adopting the present invention, since the granular irradiation object moves spirally in the peripheral portion in the tubular irradiation object passage, it is possible to move the annular area irradiated with the electron beam over a long distance. As a result, it becomes possible to more completely irradiate the surface of the granular object to be irradiated.

According to a third aspect of the present invention, there is provided a method for sterilizing a granular irradiation object according to the first or second aspect, wherein the granular irradiation object is around an axis in the irradiation object. It is a method characterized by being rotated. By adopting the present invention, the granular irradiation object is forced to rotate around the axis in the irradiation object in the peripheral portion in the tubular irradiation object passage, at a speed higher than its moving speed. Since the low-energy electron beam is irradiated while being irradiated, the entire surface of the granular irradiation target can be irradiated with the electron beam more reliably and uniformly.

The granular irradiation object sterilizing apparatus according to claim 4 of the present invention is provided with an irradiation object passage for passing a granular irradiation object and a vacuum region surrounding the irradiation object passage. And a cathode that is provided inside the vacuum container to surround the irradiation target passage and emits electrons, and provided inside the vacuum container that surrounds the irradiation target passage. And an electron accelerating means for accelerating electrons emitted from the cathode, and an electron accelerating means provided to surround the irradiation object passage and accelerated by the electron accelerating means to the outside of the vacuum container. It is characterized by including an electron transmission window. By adopting the present invention, it is possible to easily realize the sterilization method of the granular irradiation object according to claims 1 to 3.

The granular irradiation object sterilizing apparatus according to claim 5 of the present invention is the apparatus according to claim 4, wherein the electron traveling direction of the electrons passing through the electron transmitting window and the irradiation object passage are provided. It is characterized in that it is configured to include an electron concentrating means that acts so as to increase the angle formed by. By adopting this invention, the electrons transmitted through the electron transmission window travel toward the irradiation target while being perpendicular to the irradiation target passage, so that the irradiation efficiency of the irradiation target can be improved. At the same time, it becomes possible to reduce the rate at which the heat radiated from the electron transmission window reaches the irradiated body. The electron concentrating means can be easily realized by a coaxial magnet provided coaxially with the irradiation object passage while facing the electron transmitting window.

The granular irradiation object sterilizing apparatus according to claim 6 of the present invention is the apparatus according to claim 4 or 5, wherein the electron orbit from the cathode to the electron transmitting window is a cone. It is characterized by having a shape. By adopting the present invention, since the portion where the electron kinetic energy is low is located at a distant position, the electron trajectory to the electron transmission window is not easily affected by the magnet as the electron concentrating means. It was possible to realize a granular irradiation object sterilizing apparatus capable of irradiating an irradiation object with an electron beam from the entire circumferential direction while the cathode is relatively small and the whole is compact. Further, since the trajectories of the electrons that have passed through the electron passage holes of the anode are long, even if a discharge occurs between the cathode and the anode, the electron transmission window is protected from the direct hit of the discharge, and the reliability is high. It is possible to provide a high granular sterilizer for irradiated objects.

A granular irradiation object sterilizing apparatus according to claim 7 of the present invention is the apparatus according to any one of claims 4 to 6, wherein the electron transmissive window has the irradiation object or the irradiation object. It is characterized in that it comprises an irradiation object contact prevention means having a function of preventing foreign matter contained in the irradiation object from coming into contact with the irradiation object. The irradiated object contact preventing means prevents the granular irradiated object from coming into contact with the electron transmissive window even when the granular irradiated object or a foreign substance contained in the irradiated object bounces off. Not only is the electron transmissive window not damaged, but the irradiated object is not overheated by the high temperature electron transmissive window. By adopting this invention, it is possible to realize a granular irradiation object sterilizing apparatus capable of reliably irradiating a large number of granular irradiation objects with an electron beam. Even if it is provided for other purposes, the present invention is not limited as long as it has a function of preventing the irradiated body or foreign matter contained in the irradiated body from coming into contact with the electron transmission window. Corresponds to the means for preventing contact with the irradiated body.

The granular irradiation object sterilizing apparatus according to claim 8 of the present invention is the apparatus according to claim 7, wherein the irradiation object contact preventing means is the electron transmission window and the irradiation object. It is characterized in that it includes a portion having a hole or slit having an opening narrower than the width of the irradiated body between the body passage and the body passage. By adopting the present invention, it is possible to facilitate the irradiated object contact preventing means which has a simple structure and prevents the irradiated object from reaching the electron transmission window while the electrons reach the irradiated object passage. Can be realized.

According to a ninth aspect of the present invention, there is provided a granular irradiation object sterilizing apparatus according to the seventh or eighth aspect, wherein the irradiation object contact prevention means is the electron transmission window. It is characterized in that it is configured to include a portion having a foil for transmitting the electrons between the irradiation target passage and the irradiation target passage. By adopting the present invention, the irradiated body has a simple structure and prevents electrons from reaching the irradiated body passage, but prevents the irradiated body or foreign substances mixed therein from reaching the electron transmitting window. Contact prevention means can now be realized. In particular, when the object to be irradiated is a granular object containing fluid or fine powder, this foil can block the flow of fluid or fine powder.

According to a tenth aspect of the present invention, there is provided a granular irradiation object sterilizing apparatus according to any one of the seventh to ninth aspects, wherein the irradiation object contact preventing means is:
The rotary body having an opening is provided between the electron transmission window and the irradiation object passage. By adopting the present invention, it is possible to realize an irradiation object contact preventing means with a simple structure, in which electrons reach the irradiation object passage but the irradiation object does not reach the electron transmission window. In addition, the temperature rise of the structure can be prevented by the cooling effect of the fluid sprayed by the rotating portion. In particular,
When the irradiated object is a granular object containing fluid or fine powder, it is possible to push back these fluid or fine powder to the aforementioned irradiated object passage by generating pressure by the action of this rotating body. Has become.

A granular sterilizing apparatus for irradiating an irradiated object according to claim 11 of the present invention is the apparatus according to any one of claims 7 to 10, wherein the means for preventing contact with the irradiated object is the It is characterized by including a mechanism for flowing a fluid in a direction to push back the irradiation body to the passage of the irradiation body. By adopting the present invention, even when a fine powdery foreign substance is mixed in the irradiated body, or when the irradiated body contains a fluid, these substances are used as the electron transmission window. It was possible to realize a granular irradiation object sterilizer with improved reliability of the electron transmission window.

According to a twelfth aspect of the present invention, there is provided a granular irradiation object sterilizing apparatus according to any one of the fourth to eleventh aspects, wherein the irradiation object is in the irradiation object passage. It is characterized in that it comprises an irradiated object rotating means for rotating the irradiated object around an axis included in. By adopting the present invention, a granular irradiation target moving at a high speed is rotated at a high speed around an axis included in the granular irradiation target, and a low energy electron is uniformly distributed around the entire periphery of the irradiation target. We were able to realize a granular irradiation object sterilizer that can sterilize evenly by irradiating rays.

The granular irradiation object sterilizing apparatus according to claim 13 of the present invention is the apparatus according to any one of claims 4 to 12, wherein the irradiation object is provided in the irradiation object passage. It is characterized in that means is provided for spirally moving. By adopting the present invention, it is possible to move a granular irradiation target in a long distance within the electron beam irradiation region of the irradiation target passage with a simple structure, and to perform high-speed and uniform electron irradiation. We were able to realize a granular irradiation object sterilizer that can perform the radiation treatment.

The granular irradiation object sterilizing apparatus according to claim 14 of the present invention is the apparatus according to any one of claims 4 to 13, wherein at least one of the surfaces constituting the irradiation object passage is formed. It is characterized in that the fluid discharged from the individual surfaces is sprayed onto the irradiated body to rotate the irradiated body. By adopting the present invention, it is possible to blow high-pressure gas from the hole in the wall of the passage of the irradiation target to rotate the granular irradiation target at a high speed around the irradiation target passage, and to rotate the entire irradiation target. We were able to realize a granular sterilizer for irradiated objects that can uniformly perform electron beam irradiation treatment around the surroundings.

According to a fifteenth aspect of the present invention, in the apparatus for sterilizing a granular irradiation object according to any one of the fourth to fourteenth aspects, the electron transmission window is provided in the irradiation object passage. It is characterized in that it is configured so as not to be seen in the traveling direction from the irradiation target inside. By adopting the present invention, the interaction between the irradiated body and the foreign matter contained therein and the electron beam transmissive window is prevented, the reliability of the electron beam transmissive window is improved, and the heat radiated from the electron beam transmissive window is increased. It was possible to realize a granular irradiation object sterilizer with a reduced rate of reaching the irradiation object.

A method for sterilizing a granular object to be irradiated or a granular object sterilizing apparatus according to claim 16 of the present invention is the method or apparatus according to any one of claims 1 to 15 The object to be irradiated is a method or device characterized in that it is moved vertically upward from the position vertically irradiated with an electron beam. By adopting the present invention, since the granular irradiation target object can be subjected to gravitational acceleration in the same direction as the central axis of the irradiation target passage, it has an axially symmetrical distribution with respect to the central axis of the irradiation target passage. By moving while moving, the electron beam was irradiated more uniformly, and a method for more uniform sterilization and a granular irradiation object sterilizer were realized.

A method for sterilizing a granular object to be irradiated or a granular object sterilizing apparatus according to claim 17 of the present invention is the method or device according to any one of claims 1 to 16, wherein: The object to be irradiated with is a grain. It is important that the grain kills the bacteria attached to the surface without impairing the flavor, and by adopting the sterilization method and the sterilization apparatus of the present invention, the treatment speed is sufficiently increased, and the purpose is more complete. Came to be achieved.

[0033]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a simplified plan view and perspective view schematically showing a method of sterilizing a granular object according to an embodiment of the present invention, and FIG. 2 is a granular object sterilization apparatus according to an embodiment of the present invention. FIG. 3 is a vertical cross-sectional view of the electron beam irradiation apparatus used in FIG. 3, FIG. 3 is an enlarged view of a part of FIG. 2, and a cross-sectional view for explaining the operation of the present invention; FIG. 5 is a drawing for explaining the operation of the present invention, which is a transverse cross-sectional view, and FIG. 6 to 8 are principle views for explaining the principle of the electron beam irradiation apparatus used in the present invention, FIG. 9 is a vertical cross-sectional view showing another modified embodiment, and FIG.
Reference numeral 0 is a transverse sectional view showing an electron beam irradiation apparatus used in a conventional granular object sterilization apparatus. The same parts are given the same numbers. In these drawings, hatching of the cross section is partially omitted for simplification.

In FIG. 1, (a) is a simplified plan view and (b) is a simplified perspective view. As shown in FIG. 1, the granular irradiation target 100 is provided in the irradiation target carry-in path 30.
Is introduced into the spiral space 155 in the irradiation object passage, and is moved vertically downward while spiraling around the central axis along the direction 31 of the irradiation object transfer path. As will be described later, the granular irradiation target 100 moves while being rotated about an axis included in the granular irradiation target 100 by an irradiation target rotation unit (not shown), and irradiation with an electron beam is performed. It reaches the room space 111. Irradiation room space 111
Are arranged so as to surround the spiral space 155 in the irradiation object passage over the entire circumference thereof, and in this inside, the spiral space 155 is uniformly spiraled from the outer peripheral portion of the spiral space 155 in the irradiation object passage. Electron orbit 70 toward the space 155
As indicated by 1, the electron beam is irradiated. The irradiation chamber space 111 is in a state of being filled with atmospheric pressure or an inert gas or the like. The granular irradiation target 1 that has reached the irradiation chamber space 111 within the spiral space 155 in the irradiation target passage.
Since 00 moves within the spiral space 155 while rotating on its own axis, it eventually receives an electron beam over a long distance in the circumferential direction, and the entire surface of each irradiated body is uniformly sterilized. The sterilized granular irradiation target 100 further moves in the spiral space 155 and is carried out from the irradiation target carrying-out path 32. Since the granular irradiation target 100 is distributed in the peripheral portion in the irradiation target passage in an aligned state, even if the granular irradiation target 100 is moved at a high speed, the electron beam is irradiated sufficiently uniformly, and the processing speed is increased. The uniform sterilization is performed in this state. Since the granular objects 100 to be irradiated are distributed along the circumference, the installation space of the device can be reduced. Next, the electron beam irradiation device used in the granular irradiation object sterilizing apparatus of the present invention will be described.

In FIG. 2, reference numeral 1 is a vacuum container, which is a vacuum space 101 which is evacuated by a vacuum pump (not shown) connected to an exhaust pipe 16 and is constantly maintained at a vacuum degree of about 10 ⁻⁶ to 10 ⁻⁸ Torr. Is forming. Vacuum space 10
Insulating cylinder 13 is attached to the wall of vacuum container 1 inside 1, and annular electron gun mount 1 is attached to the other end of insulating cylinder 13.
4 is fixed. An annular cathode 2 and an annular focusing electrode 3 are coaxially attached to the electron gun mount 14 via an annular fitting 17. The ring-shaped cathode 2 is a barium-impregnated cathode and is heated by a heater attached inside to emit thermoelectrons. High-voltage lead wires 15 to -10 are provided for the annular cathode 2 and the heater (not shown).
A negative high voltage of about 0 KV is applied. The high voltage lead wire 15 is connected to an external high voltage power source (not shown) through a high voltage terminal (not shown). The focusing electrode 3 can apply a positive bias voltage to the cathode 2, and this bias voltage can be varied by the high voltage power source, and the distribution state of electrons can be controlled.

An anode structure 4 and an anode ring 5 for forming an annular electron passage hole 401 are coaxially provided at a position facing the cathode 2, and an electron accelerating means is formed in combination with the cathode 2. ing. The flat plate portion 402 which is a part of the anode structure 4 forms a part of the vacuum container 1. At the central position of the anode assembly 4, an irradiation object passage 10 that has reached atmospheric pressure while penetrating the anode assembly 4 is provided. Figure 2
In the flat plate portion 402 of the anode structure 4 shown in FIG.
There are a large number of dents 405 radially provided around 0, a part of which is connected to the electron passage hole 401 and forms an electron passage 406. The individual depressions 40 mentioned above
There is a partition wall (not shown) between 5 to maintain mechanical strength. A cooling water passage is provided in the vicinity of the depression 405 so that it is forcibly cooled.

As shown in FIG. 2, the electron transmissive window structure 6 is attached to the surface of the flat plate portion 402. There is a through hole in the center of the electron transmissive window structure 6 and forms a part of the irradiated body passage 10. The flat plate portion 402 and the electron transmissive window structure 6 are hermetically connected by an O-ring or the like. The electron passage window structure 6 has an irradiation object passage 10
A large number of cavities 601 radially provided around the ridge and an annular groove 602 having a portion communicating with the cavities 601 are provided. An annular cooling water passage 603 is provided in the vicinity of these, and is forcibly cooled. Individual depressions 6
There is a partition wall (not shown) between 01 to keep the mechanical strength. As shown in FIG. 2, an annular electron transmissive window 7 is airtightly attached to the end of the annular groove 602 of the electron transmissive window structure 6 by electron beam welding or the like to form a part of the vacuum container 1. The vacuum space 101 is kept in a high vacuum state. The electron transmission window 7 is made of a titanium foil having a thickness of about 10 μm, and can transmit about 50% of the incident electrons with an energy of 100 KeV.

As shown in FIG. 2, an irradiation chamber wall 11 made of a material having an atomic number smaller than iron, such as aluminum, is provided outside the electron transmission window 7 and is larger than the irradiation target passage 10. An irradiation chamber space 111 having a radius is formed. An electromagnet 8 as an electron concentrating means is attached to the outside of the irradiation chamber wall 11 at a position facing the outer surface of the electron transmitting window 7. The electromagnet 8 has an annular first magnetic pole 802 provided coaxially with the irradiation object passage 10,
An annular second magnetic pole 801 having a diameter larger than that of the first magnetic pole 802, provided coaxially therewith, a coil 803 wound therebetween, and a tip portion of the second magnetic pole 801 are provided. And a magnetic pole 804 having a smaller radius, which constitutes an electron concentrating means.

An example of the distribution of the magnetic flux 805 generated by the electromagnet 8 is shown in FIG. As shown in FIG. 5, due to the shapes of the first magnetic pole 802 and the second magnetic pole 801, a magnetic flux distribution that spreads in a cone shape on the side close to the electron transmission window 7 is exhibited. The inner diameter of the first magnetic pole 802 is equal to the electron transmission window 7
The inner diameter of the second magnetic pole 801 is larger than the outer diameter of the electron transmission window 7.

As shown in FIG. 2, a shield 12 is provided outside the electromagnet 8 to shield X-rays. The irradiation object passage 10 penetrates through the entire apparatus, and an irradiation object rotation transfer device 150 is rotatably disposed inside the irradiation object passage 10 and is rotatably supported by a bearing (not shown). At the same time, it can be rotated by a rotation drive mechanism (not shown). The irradiation object rotary transfer device 150 includes a rotary cylinder 151 and a rotary cylinder 151.
It includes an irradiation target guide 152 made of a thin spiral plate attached to the surface of and a large number of gas ejection ports 153 provided in a rotating cylinder 151. Gas such as compressed air or compressed nitrogen is supplied to the inside of the rotary cylinder 151, and is jetted at high speed into the outside irradiated object passage 10 from the gas jet port 153. The granular irradiation target 100 is a spiral space 1 surrounded by a passage inner wall 154 of the irradiation target passage 10, an outer surface of a rotating cylinder 151, and an irradiation target guide 152.
While being trapped in 55, it is transferred vertically downward while rolling. The gas ejected at a high speed from the gas ejection port 153 collides with the granular irradiation target 100 in the spiral space 155, and at a high speed around the axis included in the granular irradiation target. It is designed to be rotated. These constitute the irradiation target rotating means, and the irradiation target 1
00 is rotated at a high speed, revolves in a spiral and is transported vertically downward.

FIG. 3 shows an enlarged vertical section of a part of FIG. 2, and FIG. 4 shows the main part of the lateral sectional view taken along the line AA 'of FIG. As shown in FIG. 2 to FIG. 4, an irradiation object partition wall 156 is provided between the irradiation chamber space 111 and the irradiation object passage 10, and a granular irradiation object 100 is provided in the electron transmission window 7. It does not come in contact. The irradiation object partition wall 156 has a large number of slits 157 parallel to the central axis Z, and the irradiation chamber space 111 and the irradiation object passage 10 are provided.
Since the aperture ratio between them is 80% or more, most of the electrons flying out of the irradiation chamber space 111 are in the irradiation target passage 10.
It is absorbed by the surface of the irradiated body 100 that enters inside and passes while rotating. Although some of the electrons are absorbed by the irradiation target partition 156 and converted into heat, the temperature rise is suppressed to a low level by the heat conduction of the irradiation target partition 156 and the forced cooling effect by the high-pressure gas blowing. The irradiation target 100 contacts the irradiation target partition 156 by the high-pressure gas spraying,
The temperature of the irradiation target partition 156 is low and the irradiation target 1
I am trying not to alter 00. Further, since the surface of the ring-shaped electron transmissive window 7 is disposed orthogonal to the surface of the irradiation object passage 10, even if the electron transmissive window 7 is heated to a high temperature, its radiant heat is irradiated. Body 100
It is difficult to reach. A small amount of heat is applied to the irradiated body 100, and the irradiated body 100 is rotated at a high speed by being blown with high-pressure gas and is cooled, so that the temperature rise is suppressed to a low level.

The operation of the electron concentrating means for concentrating the electrons having passed through the electron transmitting window 7 into the irradiation passage 10 will be described below with reference to FIGS. 3 to 8. FIG. 6 is an enlarged schematic view of an annular electron transmission window 7 arranged coaxially with the surface normal line coinciding with the central axis of the irradiation object passage 10. Here, the Z axis coincides with the central axis of the irradiation object passage 10, the lower side of FIG. 2 has positive coordinates, and the R axis represents the radial direction. As shown in FIG. 6, the coordinates of an arbitrary point are represented by cylindrical coordinates (r, θ, z). At a point P ₁ (r ₁ , θ ₁ , z ₁ ) on the electron transmission window 7, electrons are incident from the annular groove 602 in the vacuum region while being inclined in the radial direction by the angle φ ₀ with respect to the Z axis. Consider the case.
The incident electrons reduce their energy and are scattered in the electron transmission window 7, and as shown in FIG. 6, the point P ₁ (r ₁ , θ
₁ , z ₁ ) and a Z-axis, and an irradiation which is an atmospheric pressure region outside the electron transmission window 7 with a velocity distribution having a three-dimensional spread in a direction orthogonal to the plane and a plane orthogonal thereto. Room space 1
Enter 11.

Point P in FIG.₁(R₁, Θ₁, Z₁) And Z axis
Fig. 7-a shows a cross-sectional view in a plane including
A cross-sectional view in the direction is schematically shown in FIG. 7-b. Figure 7-
angle φ of a₁Is the electron scattering angle in the RZ plane
This is called the radial scattering angle. Corner in Figure 7-b
Degree φ_TwoIs the scattering angle of the electron in the plane perpendicular to the RZ plane
And is referred to as the lateral scattering angle. 100 KeV luck
Initial velocity v with kinetic energy_iAt angle φ₀Only tilted
Electrons that have entered the electron transmission window 7 due to
Some reduction in initial velocity of transmitted electrons by reducing energy
To do. V this ₀Then, the R, θ, and Z directions of the transmitted electrons
Velocity component v_r, V_θ, V_zAre respectively v_r= V₀
・ Sin (φ₁-Φ₀) ・ Cos (φ_Two), V_θ= -V
₀・ Cos (φ₁-Φ₀) ・ Sin (φ_Two), V_z= V
₀・ Cos (φ₁-Φ₀) ・ Cos (φ_Two)
It

An electron concentrating hand is provided outside the ring-shaped electron transmitting window 7.
The central axis of the electromagnet 8 as a step coincides with the Z axis
And the vicinity of the inside of the electron transmission window 7.
And on the outside, as shown in FIG. 5, the magnetic flux density component in the radial direction.
B_r, Z-direction magnetic flux density component B_zMagnetic flux 805
Exists, the electrons entering this region are roughly e (v _z
B_r-V_rB_z) Is given a rotational force about the central axis
It will be. Where v_zAnd v_rIs the electron velocity in the Z direction
Minute and R direction velocity component, and e is elementary charge
It As the electron approaches the electromagnet 8, it gives a strong rotational force
Each component of magnetic flux density B_r, B_zGive the spatial distribution of
That is, the electrons move in a strong positive direction as they approach the electromagnet 8.
Trying to rotate in the positive direction around the Z axis by receiving the rotational force
It Fig.8-a shows that the electric power is rotating in the positive direction around the Z axis.
Child is magnetic flux density component, B_r, B_zDirection of force received by
Is schematically shown. In this case, the electrons rotate in the positive direction.
Force F in the direction of deceleration in the Z-axis direction while rolling_zAnd the radius
Force F in the direction of contraction_rWill be received. Figure 8-b
The electrons that are rotating in the negative direction around the Z-axis are
Degree component, B_r, B_zForce received by F_z, F_rShows
ing. In this case, the electrons rotate in the negative direction around the Z axis.
While the force F is accelerated in the Z-axis direction_zAnd the R axis
Force F in the direction diverged in the direction_rWill be received. Electric
Electron θ velocity v immediately after passing through the child transmission window 7_θIs a figure
Positive rotation is emphasized when the direction is negative in 7-b.
The electrons are close to the Z-axis while receiving a force in the Z-axis direction.
Follow on. θ direction speed v_θDeviated from the Z-axis due to the influence of
The path of this electron is the magnetic flux density component, B_r，
B_zThe closest distance to the Z axis is smaller than that when is zero
Has become. This state is schematically shown in FIGS. 3 and 4.
It

In FIG. 3, a voltage of -100 KV was applied.
Emitted from the annular cathode 2, approximately -100KV is printed.
The focused electrode 3 applied has a uniform electron density.
They are bundled to form a ring-shaped electron passage hole 401 to form the ground potential.
The electron assembly consisting of the anode structure 4 and the anode ring 5 set to
The electron beam 701 accelerated by the speed means has a cone shape.
Traveling through the orbit of
Lateral scattering angle with kinetic energy of 80 KeV
φ_Two, Radial scattering angle φ₁Orbit of electrons scattered by R
It is schematically shown by being projected on the Z plane. Above electron transparent window 7
Point P₁(R₁, Θ ₁, Z₁) The electron transmitted in
Radial scattering angle φ₁The electrons scattered by
If there is no electromagnet 8 as described above, place it in the atmosphere.
Ignoring the effect of scattering due to
It travels linearly and does not reach the irradiated body 100. Accuse
If the electromagnet 8 is present in the
Density component, B_r, B_zDeflected by and represented by the solid line
As shown by the trajectory 702, the angle formed with the irradiation object passage 10
Becomes larger and travels, reaching the irradiated body 100
The proportion of electrons is increasing.

In FIG. 4, the annular groove 6 in the vacuum region
A representative example of the trajectories of the electrons approaching the electron transmission window 7 through 02 is shown in 701. It travels from the portion of the average radius of the annular cathode 2 and enters the electron transmission window 7 at a point P ₁ (r ₁ , θ ₁ , z ₁ ) and scatters with a radial scattering angle φ ₁ and a lateral scattering angle φ _2. The orbits of the generated electrons are schematically shown at 702. These electron trajectories 702 do not reach the irradiation target when the electromagnet 8 is absent, that is, when the magnetic flux density B is 0, since they travel in a substantially straight line, ignoring the influence of scattering in the atmosphere. However, as can be seen from FIG. 4, when the magnetic flux density B of the electromagnet 8 is set to an optimum value, the irradiated body 10 is irradiated with an electron trajectory 702 by the effect of the electron concentrating means.
It is bent toward 0, and the irradiated body 100 is irradiated. By providing the electromagnet 8 in this manner, the closest distance of the electron orbit to the Z-axis can be made small, so that the outer peripheral surface of the irradiation object passage 10 is approached at an angle approaching perpendicularly and the electrons to the irradiation object 100 are absorbed. The hit rate improves. On the other hand, even when the initial velocity v _θ in the θ direction is the positive direction in FIG. 7-b, the positive direction rotational force due to the magnetic flux density increases with the progress of the electrons, and the electrons rotate in the positive direction. As a result, the same concentration effect as described above is produced. Although the above description ignores the influence of scattering in the atmosphere, it is clear that the same concentration effect is produced even when the scattering in the atmosphere is taken into consideration.

Although the electron orbits under the typical operating conditions have been described above, similar effects can be obtained even when the radial scattering angle φ ₁ is different or the transmitted electron energy is different. By providing the electromagnet 8 as the electron concentrating means of the present invention, the hit rate of the electrons transmitted through the electron transmissive window 7 to the irradiated object 100 is improved as a whole, and the electron density in the electron transmissive window 7 is not increased. An electron beam irradiation device capable of irradiating the irradiation object 100 with a large amount of electrons and a granular irradiation object sterilization device using the same can be realized.

As described above, due to the electron concentration effect of the electromagnet 8 which is an example of the electron concentration means, the electrons transmitted through the electron transmission window 7 reach the irradiated object 100 in the RZ plane direction and the Rθ plane direction. The object to be irradiated 100 is deflected as it approaches.
It has been confirmed by experiments that the number of electrons radiated on the slab increases by a total of about three times or more. As shown in FIG. 4, a large number of similarly irradiated electrons 100 are irradiated from the entire periphery of the irradiation object passage 10. Since a large number of granular objects 100 to be irradiated move in the Z-axis direction along the outer peripheral region of the object passage 10 in a spiral path while rotating at a high speed as described above, all of the individual objects 100 to be irradiated are rotated. The surface is uniformly irradiated with the electron beam. Since the kinetic energy of the irradiated electrons is as low as about 80 KeV, it is absorbed only by the surface of the irradiated body 100 and does not reach the deep part. Further, since the surface normal of the electron transmission window 7 is parallel to the central axis Z of the irradiation object passage 10, it is difficult for the radiant heat from the electron transmission window 7 to reach the irradiation object 100.

EXAMPLES Next, the operation and effect of the electron beam irradiation apparatus used in the granular irradiation object sterilizing apparatus of the present invention will be further described with reference to Examples. The inner diameter of the irradiation object passage is 10 cm, and the electron transmission window 7 has a thickness of 10 μm and an outer diameter of 16 cm.
It is composed of an annular thin film of titanium having an inner diameter of 12 cm, the surface area is 88 cm ² , and the case where electrons are uniformly spread and incident on this surface will be described. The electron incidence density that is acceptable for such a thin film while maintaining reliability is usually 2
Since it is about 0 W / cm ² , the allowable input in this embodiment is 1760 W. Energy of incident electron is 100
At KeV, this corresponds to a current of 17.6 mA. About 50% of the incident electrons are absorbed by the electron transmission window 7, and the remaining about 50% is transmitted with a kinetic energy of about 80 KeV. The power of the transmitted electrons is 704W. If the irradiated object 100 is a sphere with a radius of 2.5 mm and the density is 1.2 g / cm ³ ,
Since the depth at which the electron beam penetrates is approximately 40 μm, the volume of each portion irradiated with the electron beam is 0.0031.
cm ³ , and the mass of this portion is 0.0037 g. In the case where the electromagnet 8 as the electron concentrating means is not used, 8% of the power of the transmitted electrons is the irradiated object 1.
Hitting 00, 2KGy per irradiated object
If it is necessary to irradiate a dose of
Thus, g of irradiation object can be processed.

When an appropriate magnetic flux density is given by the electromagnet 8 as the electron concentrating means to improve the hit rate to the irradiated object 100 by about 3 times, the processing speed of the irradiated object 100 is improved to 105 kg per minute. Since the total length of one electron beam irradiation apparatus is about 50 cm, the irradiation dose of the irradiation target 100 can be increased by using the apparatuses connected in series. For example, if five units are connected in series, the total length of the device will be 2.5 m, but the irradiation dose of the irradiated object 100 will be 20K.
It is enhanced by Gy, and a sufficient irradiation dose can be obtained.
Further, if it is necessary to increase the processing speed, the area of the electron transmissive window 7 is increased to broaden the distribution of the electrons incident on the electron transmissive window 7 and the electron density in the electron transmissive window 7 is kept small. This can be easily achieved by transmitting 7 and hitting the subject with the transmitted electrons by the electron concentrating means. The broadening of the electron distribution can be easily realized by, for example, increasing the bias voltage of the focusing electrode 3 as the electron dispersing means. The processing speed can be further increased by providing radial fins on at least one surface of the electron transmission window 7 to cool the electron transmission window better. Moreover, the processing speed can be increased without limit by operating the electron beam irradiation devices in parallel. In this case, since each electron beam irradiation apparatus is compact, the installation space does not become too large, and the granular irradiation object sterilizing apparatus of the present invention can be operated in an inexpensive facility.

In the above-described embodiments and examples, the electron gun has an annular cathode 2, and its central axis is attached concentrically with the central axis of the irradiated body passage 10, but its diameter is 4 mm. Needless to say, a large number of circular cathodes may be arranged in a ring shape. In this case, there is an advantage that an existing cathode can be adopted. Needless to say, the focusing electrode 3 of the electron gun may be similarly divided into a plurality of pieces. Of course, the electron transmission window 7 may also be formed in an annular shape with a plurality of divided segments.

The irradiation chamber space 111 has an inlet 112 and an outlet 113 for the inert gas, and the inert gas is blown onto the electron transmission window 7 to forcibly cool it. Since this inert gas moves at a high speed in the direction of the irradiated body passage 10, even if fine particles or fluid flies from the irradiated body passage 10, there is an action of pushing them back.
It functions as one of the means for preventing contact with the irradiated body. It is made of a material having an atomic number smaller than iron, such as aluminum, so as to reduce the generation of X-rays when the electrons transmitted through the electron transmission window 7 collide with the wall 11 of the irradiation chamber space 111.

Next, a modified embodiment will be described with reference to FIG. In FIG. 9, a cylindrical fan-shaped structure having a slit 157 is adopted as a means for preventing contact with the irradiated body, and the blade 158 has an angle and the irradiation chamber space 11
It is rotatably attached to the periphery of the irradiation object passage 10 in the inside 1. Since it is rotated at a high speed in the direction of arrow 159 by a rotation drive mechanism (not shown), the inert gas blown from the electron beam transmission window 7 has a high pressure and is exposed to the irradiation target passage 1
It is sprayed within 0. When the irradiated body 100 contains fine particles or fluid, the gas pressure pushes these fine particles or fluid back into the irradiated body passage 10, so that the reliability of the electron transmission window 7 is improved. . When this irradiation target contact prevention means is adopted, even if the irradiation target 100 contains a fluid such as a toxic gas, the irradiation target 100 is prevented from reaching the electron transmission window 7, and the electron beam of the present invention is used. The irradiation device is effective. If the irradiated part may be damaged by the rotating part, the rotating structure shown in FIG. 9 may be attached around the fixed structure with slits shown in FIG. This can be solved by arranging a thin film inside which allows transmission, but does not pass through the irradiation target.

Although the present invention has been described in connection with the embodiments and examples, the present invention is not limited to the structures and configurations of the embodiments and examples illustrated herein, but the spirit and scope of the present invention. It should be understood that various embodiments are possible and various changes and modifications can be made without departing from the above. For example, it goes without saying that the electromagnet 8 as the electron concentrating means may be replaced with a permanent magnet. Further, in the present embodiment shown in FIG. 2, the electron transmission window 7 is formed in the shape of a circular flat plate for easy fabrication, but it may be formed in the shape of a cone. It goes without saying that the structure serving as the means for preventing contact with the irradiated body may have a mesh structure. It goes without saying that the rotating body as the means for preventing contact with the irradiated body may be provided in parallel with the electron transmission window. As the means for preventing contact with the irradiated body, a plurality of means of the same kind or different kinds may be adopted. Further, it goes without saying that the irradiation target may be configured to move in the horizontal direction. In the examples shown in FIGS. 2, 3, 4, and 9, the electron beam flying from the opposite direction is blocked by the rotating cylinder 151 and the like, but the rotating cylinder 151 and the like are made transparent such as a wire mesh. If changed, the electron beam is irradiated from both sides of the irradiation target 100, and the uniformity of irradiation dose is further improved. In this case, this part does not necessarily have to rotate, and the irradiated body transfer device 150 may be eliminated and the irradiated body may be allowed to fall naturally. In the present invention, the tubular irradiation object passage includes cases other than a circle, such as a case where the cross section is elliptical or a square. Even if the irradiation of the electron beam is partially or intermittently lost in the circumferential direction of the irradiation object passage, it can be regarded as the irradiation of the electron beam substantially from the entire circumferential direction of the irradiation object passage, Of course, it is included in the present invention. In the present invention, sterilization is used in a broad sense, and so-called sterilization is also included.

As described above, when the granular irradiation object sterilizing method or granular irradiation object sterilizing apparatus of the present invention is adopted, the electron beam is evenly distributed only on the surface portion of an object having a granular shape such as grain. Without irradiating the inside,
The surface of this granular object can be completely sterilized and the sterilization speed can be increased. The apparatus for sterilizing granular object to be irradiated of the present invention is compact, and the processing speed can be increased by connecting and operating in parallel or in series in a small installation space. Furthermore, the electron transmission window is invisible from the traveling direction of the irradiation target, and the irradiation target and foreign substances contained in the irradiation target are prevented from approaching the electron beam transmission window. The sex is extremely high.

[Brief description of drawings]

FIG. 1 is a simplified plan view and perspective view schematically showing a method of sterilizing a granular object according to an embodiment of the present invention.

FIG. 2 is a vertical cross-sectional view of an electron beam irradiation apparatus included in the granular irradiation object sterilization apparatus according to one embodiment of the present invention.

FIG. 3 is an enlarged view of a part of FIG. 2, which is a vertical cross-sectional view of an embodiment of the present invention.

4 is a vertical cross-sectional view of an embodiment of the present invention, FIG. 2A
It is a cross-sectional view seen from the arrow direction of A ′.

FIG. 5 is a cross-sectional view showing a structure of an electromagnet as an electron concentrating means which is a main component of the present invention and a magnetic flux distribution.

FIG. 6 is a principle diagram for explaining the principle of the present invention, schematically showing scattering of electrons in an electron transmission window.

FIG. 7 is a principle diagram illustrating the principle of the present invention, showing an angular relationship of electron scattering in an electron transmission window.

FIG. 8 is a principle diagram illustrating the principle of the present invention, showing the effect of magnetic flux density on orbiting electrons.

FIG. 9 is a transverse cross-sectional view showing a part of a granular irradiation object sterilizing apparatus according to a modified embodiment of the present invention.

FIG. 10 is a schematic cross-sectional view of an electron beam irradiation apparatus used in a conventional granular object sterilization apparatus.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Vacuum container 2 Cathode 3 Focusing electrode 4 Anode structure 5 Anode ring 6 Electron transmission window structure 7 Electron transmission window 8 Electromagnet 9 Intersection point 10 between an extension line of a cone-shaped electron orbit of an electron beam and a center line of the irradiation object passage 10. Irradiation body passage 11 Irradiation chamber wall 12 Shield 13 Insulation cylinder 14 Electron gun mounting base 15 High voltage lead wire 16 Exhaust pipe 17 Mounting bracket 30 Irradiation body carry-in path 31 Irradiation body transfer path direction 32 Irradiation body carry-out path 100 Irradiation object 101 Vacuum space 111 Irradiation chamber space 112 Gas inlet port 113 Gas exhaust port 150 Irradiation object rotary transfer device 151 Rotating cylinder 152 Irradiation object guide 153 Gas ejection port 154 Irradiation object passage inner wall 155 Spiral shape Space 156 Irradiation object partition 157 Slit 158 Blade 401 Electron passage hole 402 Flat plate part 405 which is a part of the anode assembly 4 Large number of dents 40 provided radially 6 Electron passage 601 A large number of dents 602 provided in a radial pattern. Ring groove 603 Cooling channel 701 Electron trajectory 702 Electron trajectory 702 'Electron trajectory 801 Annular second magnetic pole 802 Annular first magnetic pole 803 Coil 804 Magnetic pole 805 Equal magnetic field Position curve

Claims (17)

[Claims] 1. A cylindrical irradiation object is distributed in a peripheral portion of an irradiation object passage formed in a cylindrical shape, and while moving along the cylindrical irradiation object passage, A method for sterilizing a granular object to be irradiated, comprising irradiating the particle-shaped object to be irradiated with an electron beam from the entire outer peripheral direction of the object path. 2. The method of sterilizing a granular irradiation target according to claim 1, wherein the granular irradiation target moves spirally in the tubular irradiation target passage. 3. The method for sterilizing a granular irradiation target according to claim 1, wherein the granular irradiation target is rotated about an axis in the irradiation target. 4. An irradiation target passage for passing a granular irradiation target, a vacuum container surrounding the irradiation target passage and forming a vacuum region, and the inside of the vacuum container, A cathode that surrounds the irradiation target passage and emits electrons, and an electron that surrounds the irradiation target passage inside the vacuum container and accelerates the electrons emitted from the cathode. It is configured to include an accelerating means and an electron transmitting window that is provided so as to surround the irradiation target passage and that transmits electrons accelerated by the electron accelerating means to the outside of the vacuum container. Granular irradiation object sterilizer. 5. An electron concentrating means is included which acts so as to increase the angle formed between the traveling direction of the electrons transmitted through the electron transmission window and the irradiation object passage. The granular irradiation object sterilization apparatus according to claim 4. 6. The granular irradiation object sterilizing apparatus according to claim 4, wherein an electron orbit from the cathode to the electron transmitting window has a cone shape. 7. The irradiated body contact preventing means having a function of preventing the irradiated body or foreign matter contained in the irradiated body from coming into contact with the electron transmission window. The granular irradiation object sterilizer according to any one of claims 4 to 6. 8. The means for preventing contact with the irradiated body comprises a hole or slit having an opening narrower than the width of the irradiated body between the electron transmitting window and the irradiated body passage. The apparatus for sterilizing the granular irradiation object according to claim 7, wherein the apparatus for sterilizing granular objects to be irradiated is configured to include a portion that has. 9. The means for preventing contact with the irradiated body is configured to include a portion having a foil for transmitting the electron between the electron transmitting window and the passage for the irradiated body. 9. The granular irradiation object sterilizing apparatus according to claim 7, wherein 10. The irradiation target contact preventing means is configured to include a rotating body having an opening between the electron transmission window and the irradiation target passage. The granular irradiation object sterilizer according to any one of claims 7 to 9. 11. The irradiated body contact preventing means includes a mechanism for flowing a fluid in a direction to push back the irradiated body or foreign matter contained in the irradiated body to the irradiated body passage. The granular irradiation object sterilizer according to any one of claims 7 to 10. 12. An irradiation object rotating means for rotating the irradiation object around an axis included in the irradiation object in the irradiation object passage, is constituted. 4. The granular irradiation object sterilizer according to any one of 4 to 11. 13. The granular irradiation object according to claim 4, further comprising means for moving the irradiation object spirally in the irradiation object passage. Sterilizer. 14. The irradiation target is rotated by spraying fluid discharged from at least one surface of the surface forming the irradiation target passage. The granular irradiation object sterilizer according to any one of claims 4 to 13. 15. The electron transmissive window is configured so as not to be seen in the traveling direction of the irradiation target existing in the irradiation target passage. The granular irradiation object sterilizer according to one. 16. The granular object to be irradiated is moved from a vertically upper position to a vertically lower position at a position where it is irradiated with an electron beam, according to any one of claims 1 to 15. A method for sterilizing a granular object to be irradiated or a granular sterilizer for an object to be irradiated. 17. The method for sterilizing a granular irradiation target or the apparatus for sterilizing a granular irradiation target according to claim 1, wherein the granular irradiation target is a grain.