JP2002350600A - Electron beam irradiator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electron beam irradiator which enables a complete electron beam treatment for the whole surface of a granular object to be irradiated by uniformly irradiating the whole surface of the object with an electron beam without altering the quality inside the object and is compact and highly reliable. SOLUTION: The hit probability of the object 100 to be irradiated is heightened by accelerating between a cathode 2 and an anode with an electron transmission hole 401 electrons emitted from the cathode 2 placed in a vacuum region where a high vacuum condition is maintained to transmit the electrons through an electron transmission window 7 and concentrating the transmitted electrons on the object 100 with an electromagnet 8 located concentrically with the electron transmission window 7. At the same time, the surface of the granular object 100 is uniformly irradiated with the electron beam while keeping the granular object 100 out of contact with the electron transmission window 7 and rotating the object 100 with an object rotation means to move it vertically downward in the cylindrical region mentioned above.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for sterilizing bacteria adhering to the surface of a granular object and for curing or modifying a resin applied to the surface of a granular object. A device for irradiating an object to be irradiated with electrons while rotating and moving the body at a high speed, and in particular, a granular object to be irradiated traveling at a high speed, and an electron for transmitting electrons from inside a vacuum region to outside the vacuum region. The present invention relates to an electron beam irradiation apparatus characterized by preventing interaction with a transmission window to enhance reliability, and uniformly irradiating an electron beam on a surface of the irradiation object by rotating the irradiation object.

[0002]

2. Description of the Related Art A conventional electron beam irradiation apparatus is disclosed in Japanese Patent Laid-Open Publication No. Hei 11-19190, in which a linear metal filament is mounted in a fixed drum-shaped vacuum vessel. The thermal electrons emitted by energizing and heating this are accelerated at a voltage of 500 KV or less, and transmitted through a flat electron transmission window made of thin metal foil to irradiate an electron beam on an irradiation target in the atmosphere. It is supposed to. FIG. 9 shows a schematic cross-sectional view of a conventional electron beam irradiation apparatus. 9, reference numeral 1001 denotes a vacuum vessel; 1003, an electron gun structure; 1002, a terminal for supporting the electron gun structure 1003;
04 is a cathode filament, 1005 is a grid, and 1006 is an electron transmission window for transmitting electrons.
Electrons emitted from the cathode filament 1004 are accelerated by a potential difference applied to the grid 1005, and further accelerated by a potential difference of 500 KV or less applied between the grid 1005 and the electron transmission window 1006. The transmitted electron beam B01 irradiates the irradiated object 1011 that falls in the direction of arrow 1010 from the direction of arrow 1009 in the irradiation chamber. This device is large and suitable for irradiating a sheet-shaped object with an electron beam because the irradiation direction of the electron beam is constant. Not suitable for In such a case,
For example, a method of irradiating an electron beam while rolling an irradiation object 1011 on an inclined surface as described in Japanese Patent Application Laid-Open No. H10-268100, or a method of irradiating a granular irradiation object vertically downward as shown in FIG. A method of irradiating an electron beam from the side while falling is adopted. In such a case, not only the entire surface of the granular irradiation target cannot be uniformly irradiated with the electron beam, but also the granular irradiation target collides with the electron beam transmission window and the electron transmission window is damaged. There was a problem that frequently occurs.
Further, there is a disadvantage that the heat of the electron beam transmission window heated by the absorption of the electron beam overheats the irradiation target and alters the irradiation target.

[0003] In particular, when the irradiated object sterilizes the surface of, for example, a grain with a shell, the grain is spread over a length of about 1 m from the lateral direction while being naturally dropped while being spread in a sheet shape. A method of irradiating an electron beam is used. In this case, the energy of the electron beam is reduced to about 100 KeV in order to prevent the electron beam from entering the grain,
The electron beam is absorbed in the shell. Therefore,
If the electron beam is irradiated from one direction, the surface of the grain in the opposite direction will not be sterilized. Therefore, even if sterilization by the electron beam is performed, the bacterial content cannot be significantly reduced. Also, the above-mentioned spread and distributed electron beam is
It is possible to irradiate the grain that spreads in a sheet form and falls naturally from both sides, and in this case, it is possible to reduce the bacterial content from the above case,
Not perfect yet. Furthermore, even if the grain to be sterilized is slid down on an inclined surface, it is difficult to irradiate the surface of the grain with an electron beam uniformly because the grain is not only a perfect sphere, but the rolling axis tends to be constant. There is a problem that complete sterilization cannot be performed.

In any of the above-mentioned examples, it is necessary to distribute objects to be irradiated, such as grains, in a sheet shape having a width of more than 1 m, which not only increases the size of the apparatus but also makes it expensive. The installation place of the device has been widened, and there has been a problem in securing the installation place. In particular, in the method of irradiating an electron beam from two opposing directions, both the volume and the cost of the device are approximately doubled. A similar problem arises when the irradiation target slides on an inclined surface. Further, since the temperature of the electron beam transmission window is increased, radiant heat is given to the irradiation target, and the irradiation target may be deteriorated. Further, there is a problem that the granular irradiation object jumps and collides with the electron beam transmission window to be damaged.

[0005]

The problem to be solved is to cure or modify the resin applied to the surface of an object having a granular shape, and to sterilize the surface, etc. When irradiating the irradiating object with the electron beam, the above processing can be performed in a narrow place without spreading these irradiating objects into a sheet shape, and the granular irradiating object can be irradiated without altering the inside of the irradiating object. An object of the present invention is to provide a compact and highly reliable electron beam irradiation apparatus that can uniformly irradiate an electron beam over the entire surface and completely treat the entire surface of an irradiation target with an electron beam. In particular, it is an object of the present invention to provide a highly reliable electron beam irradiation apparatus by preventing a granular irradiation object from jumping and coming into contact with an electron transmission window.

[0006]

According to the present invention, electrons emitted from a cathode provided in a vacuum region maintained in a high vacuum state are accelerated between an anode having an electron passage hole and a cone-shaped electron. After traveling on the orbit, the electron beam passes through an electron transmission window for taking out of the vacuum area, and the transmitted electrons pass from the entire circumferential direction of the irradiation object passage having a cylindrical area to the cylindrical area. By using the electron concentrating means for deflecting in the direction to be directed and the irradiation object rotating means for moving the irradiation object while rotating in the cylindrical area, the granular particles passing while rotating in the irradiation object passage are used. Electrons are evenly collided with the entire surface of the irradiation target, thereby greatly improving the hit rate on the entire surface of the irradiation target.

By using a magnet arranged coaxially with the irradiation object passage as one of the electron concentrating means, a magnetic flux density component parallel to the irradiation object passage and a central axis of the irradiation object passage can be adjusted. A space having a heading magnetic flux density component is formed, electrons are caused to travel in this space, and due to the interaction between the magnetic flux density component and the electrons, a strong rotational force around the central axis is received as the electrons travel. At the same time, it approaches the central axis of the irradiation object passage.

The object to be irradiated is moved vertically downward while spirally moving in the cylindrical area by a rotary transfer device having a spiral object guide in the cylindrical area. At the same time, it is rotated at a high speed by compressed gas which is jetted at a high speed from a number of gas jets between the spiral object guides. By such an irradiating object rotating means, the granular irradiating object can be moved vertically downward in the cylindrical region while rotating both in rotation and revolution, but uniformly from the outer periphery of the cylindrical region. Is irradiated with an electron beam, so that the surface of the granular object to be irradiated is uniformly treated with the electron beam. Assuming that the density of the surface layer of the irradiation object is about 1 g / cm ³ , the irradiated electron beam does not penetrate deeper than about 0.1 mm and does not affect the inside of the irradiation object.

The electron transmission window is provided so as to annularly surround the irradiation object passage. The surface of the electron transmission window has an angle with the outer surface of the irradiation object passage. Radiation heat coming out of the window hardly reaches the irradiated object. In addition, there is an irradiation object partition wall as an irradiation object contact preventing means between the irradiation object passage and the electron transmission window, so that the irradiation object cannot reach the electron transmission window. The irradiation target partition has a slit or a hole, and an electron beam can pass therethrough but cannot pass through the irradiation target. When a fluid is contained in the irradiation object, a rotating body such as a fan having a slit is provided as the irradiation object contact prevention means, thereby preventing the fluid from reaching the electron transmission window.

An electron beam irradiating apparatus according to claim 1 of the present invention comprises: a vacuum vessel forming a vacuum region; an irradiation object passage for passing an irradiation object outside the vacuum container; A cathode that emits electrons inside the vacuum vessel of, and electron acceleration means that accelerates electrons emitted from the cathode,
An electron transmitting window for transmitting electrons accelerated by the electron accelerating unit to the outside of the vacuum vessel, and an irradiation target contact preventing unit for preventing the irradiation target from contacting the electron transmitting window. It is characterized by comprising. The illuminated body contact preventing means prevents the granular illuminated body from contacting the electron transmission window even when the granular illuminated body jumps, so that the electron transmission window is damaged. In addition, the irradiation target is not heated by the high-temperature electron transmission window. By employing the present invention, an electron beam irradiation apparatus capable of irradiating a large number of granular objects with an electron beam with high reliability was realized.

According to a second aspect of the present invention, there is provided an electron beam irradiating apparatus according to the first aspect, wherein an advancing direction of the electrons transmitted through the electron transmission window and the passage of the object to be irradiated are formed. The present invention is characterized in that it is provided with electron concentration means that acts to increase the angle.
By employing the present invention, the electrons transmitted through the electron transmission window travel toward the irradiation target in a state approaching perpendicular to the irradiation target passage, so that the irradiation efficiency to the irradiation target can be increased. At the same time, the rate at which heat radiated from the electron transmission window reaches the irradiation target can be reduced.

According to a third aspect of the present invention, there is provided the electron beam irradiation apparatus according to the first or second aspect, wherein the electron transmission window is provided so as to surround the object to be irradiated. It is characterized in that it is configured to have an angle with the irradiation object passage. By adopting the present invention, an electron beam is uniformly irradiated from all directions around the irradiation object passing through the irradiation object passage, and the electron transmission window does not face the irradiation object passage in parallel. This makes it difficult for heat radiated from to reach the irradiation object, and high-quality electron beam processing can be performed.

According to a fourth aspect of the present invention, there is provided an electron beam irradiating apparatus according to any one of the first to third aspects, wherein the illuminated object contact preventing means includes the electron transmission window and the electron transmission window. And a structure having a hole or a slit having an opening smaller than the width of the irradiation object between the irradiation object passage and the irradiation object passage. By adopting the present invention, an irradiation object contact preventing means for preventing electrons from reaching the irradiation object passage, but preventing the irradiation object from reaching the electron transmission window can be realized with a simple structure. In addition to this, even if electrons are absorbed in this portion, the rise in temperature can be prevented by heat conduction of the structure.

According to a fifth aspect of the present invention, there is provided an electron beam irradiating apparatus according to any one of the first to fourth aspects, wherein the means for preventing contact with the illuminated object includes the electron transmission window and the electron transmission window. A rotating body having an opening portion is provided between the rotating body and the irradiation object passage. By adopting the present invention, with a simple structure,
It is possible to realize an irradiation object contact preventing means for preventing electrons from reaching the irradiation object passage, but preventing the irradiation object from reaching the electron transmission window, and also to cool the fluid spray by the rotating portion. The effect can prevent the temperature of the structure from rising. In particular, when the irradiation target is a fluid or a granular object containing a fluid, by generating pressure by the rotating body, the fluid can be pushed back to the irradiation target passage. It has become.

According to a sixth aspect of the present invention, there is provided an electron beam irradiation apparatus according to the first to fifth aspects, wherein said means for preventing contact with the illuminated object comprises: It is characterized by including a mechanism for flowing a fluid in a direction of pushing back to the body passage. By employing the present invention, even when a fine powdery object is mixed in the irradiation target, or even when the irradiation target contains a fluid,
These substances can be prevented from reaching the above-mentioned electron transmission window, and an electron beam irradiation device with improved reliability of the electron transmission window can be realized.

According to a seventh aspect of the present invention, there is provided an electron beam irradiation apparatus according to any one of the first to sixth aspects, wherein the irradiation object passage is formed in a cylindrical shape.
The irradiation object moves close to the outer periphery of the irradiation object passage, and the accelerated electrons are irradiated from the periphery of the irradiation object passage toward the irradiation object. It is. By adopting the present invention, it is possible to increase the processing capacity in a narrow installation place by irradiating a large amount of irradiated objects spread over the entire circumference in a short time while keeping the entire apparatus compact. It became so.

According to an eighth aspect of the present invention, there is provided an electron beam irradiation apparatus according to any one of the first to seventh aspects, wherein the irradiation object rotates in the irradiation object passage. An irradiation object rotating means is provided. By employing the present invention, it is possible to realize an electron beam irradiation apparatus capable of uniformly rotating the entire periphery of the irradiation target by rotating the granular irradiation target moving at a high speed more rapidly.

According to a ninth aspect of the present invention, there is provided an electron beam irradiating apparatus according to any one of the first to eighth aspects, wherein the illuminated object is provided in the illuminated object passage. It is characterized in that a means for spirally moving is provided. By adopting the present invention, it is possible to move the granular irradiation object over a long distance along the periphery of the electron beam irradiation position of the irradiation object passage with a simple structure, and to achieve high speed and uniformity. An electron beam irradiation apparatus capable of performing electron beam irradiation processing has been realized.

According to a tenth aspect of the present invention, there is provided the electron beam irradiation apparatus according to the first aspect, wherein at least one of the surfaces constituting the passage of the object to be irradiated is provided. It is characterized by being configured to mechanically vibrate or rotate or move. By adopting the present invention, the electron beam irradiation process can be performed at high speed and uniformly by moving the granular object with a simple structure along the periphery of the object path and rotating the granular object by itself. An electron beam irradiation device that can be performed has been realized.

According to an eleventh aspect of the present invention, there is provided an electron beam irradiation apparatus according to any one of the first to tenth aspects, wherein at least one of the surfaces constituting the passage of the object to be irradiated is provided. The apparatus is characterized in that the object is rotated by spraying a fluid onto the object. By employing the present invention, a high-pressure gas can be blown from a hole in a wall of an irradiation object to rotate a granular irradiation object at a high speed around the irradiation object passage, and the entire irradiation object can be rotated. An electron beam irradiation apparatus capable of uniformly performing electron beam irradiation processing over the periphery was realized.

According to a twelfth aspect of the present invention, there is provided an electron beam irradiation apparatus according to the third aspect, wherein the electron transmission window is formed substantially orthogonal to the irradiation object passage. It is characterized by the following. By employing the present invention, an electron beam irradiation window can be easily manufactured, and an electron beam irradiation apparatus in which the rate of heat radiated from an electron beam transmission window reaching an object to be irradiated is minimized can be realized. Was.

According to a thirteenth aspect of the present invention, in the electron beam irradiation apparatus according to any one of the first to twelfth aspects, the trajectory of electrons incident on the electron transmission window is controlled by the irradiating object. Is at an acute angle to the direction in which it moves. By employing the present invention, not only is the electron trajectory up to the electron transmissive window hardly affected by the magnet as the electron concentrating means, but the cathode can be reduced in size, and the whole is compact, An electron beam irradiation device capable of irradiating an object to be irradiated with an electron beam from all directions has been realized.

[0023]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a longitudinal sectional view of an electron beam irradiation apparatus according to one embodiment of the present invention, FIG. 2 is an enlarged view of a part of FIG. 1, and FIG. 3 is a sectional view for explaining the operation of the present invention. FIG. 1 is a cross-sectional view taken along the line AA ′ of FIG. 1 and is a drawing for explaining the operation of the present invention. FIG. FIG. 5 to FIG. 7 are principle diagrams for explaining the principle of the present invention, FIG. 8 is a longitudinal sectional view showing another modified embodiment, and FIG. 9 shows a conventional electron beam irradiation apparatus. FIG. The same parts are given the same numbers. For the sake of simplicity, cross-sectional hatching is partially omitted.

In FIG. 1, reference numeral 1 denotes a vacuum vessel which evacuates a vacuum space 101 which is evacuated by a vacuum pump (not shown) connected to an exhaust pipe 16 and is always kept at a degree of vacuum of about 10 ^-6 to 10 ^-8 Torr. Has formed. Vacuum space 10
1, an insulating cylinder 13 is attached to the wall of the vacuum vessel 1 and the other end of the insulating cylinder 13 has an annular electron gun mounting base 1 attached thereto.
4 is fixed. The annular cathode 2 and the annular focusing electrode 3 are coaxially attached to the electron gun mounting base 14 via an annular mounting member 17. The annular cathode 2 is a barium-impregnated cathode, and emits thermoelectrons when heated by a heater mounted inside. The high voltage leads 15 to -10 are connected to the annular cathode 2 and the heater (not shown).
A negative high voltage of about 0 KV is applied. The high voltage lead 15 is connected to an external high voltage power supply (not shown) via a high voltage terminal (not shown). A positive bias voltage can be applied to the focusing electrode 3 with respect to the cathode 2, and this bias voltage can be varied by the high-voltage power supply so that 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 provided coaxially at a position facing the cathode 2. Electron acceleration 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 vessel 1. At the center position of the anode structure 4, there is provided an irradiation object passage 10 which is at atmospheric pressure while penetrating the anode structure 4. FIG.
In the flat plate portion 402 of the anode structure 4 shown in (1), there are a large number of radially provided depressions 405, some of which are connected to the electron passage holes 401 to form electron passages 406. There are partition walls (not shown) between the individual depressions 405 to maintain mechanical strength. A cooling water passage is provided in the vicinity of the depression 405 so as to be forcibly cooled.

As shown in FIG. 1, an electron transmission window structure 6 is mounted on the surface of the flat plate portion 402. There is a penetrating hole at the center of the electron transmission window structure 6 and forms a part of the irradiation object passage 10. The flat plate portion 402 and the electron transmission window structure 6 are airtightly connected by an O-ring or the like. The electron transmission window structure 6 has a large number of depressions 601.
And an annular groove 602 having a portion communicating therewith. An annular cooling water passage 603 is provided in the vicinity of these, and is forcibly cooled. There are partition walls (not shown) between the individual recesses 601 to maintain mechanical strength. As shown in FIG. 1, an annular electron transmission window 7 is hermetically attached to an end of the annular groove 602 of the electron transmission window structure 6 by electron beam welding or the like, and forms a part of the vacuum vessel 1. The vacuum space 101 is kept in a high vacuum state. The electron transmission window 7 has a thickness of 10 μm.
It is made of a small amount of titanium foil and can transmit about 50% of incident electrons with an energy of 100 KeV.

As shown in FIG. 1, 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 above-described irradiation object passage 10. An irradiation chamber space 111 having a radius is formed. At a position facing the outer surface of the electron transmission window 7, an electromagnet 8 as an electron concentrating means is mounted outside the irradiation chamber wall 11. The electromagnet 8 includes an annular first magnetic pole 802 provided coaxially with the irradiation object passage 10,
It is provided coaxially therewith and has an annular second magnetic pole 801 having a diameter larger than that of the first magnetic pole 802 and a coil 803 wound therebetween to form an electron concentrating means. are doing. A magnetic pole 804 having a smaller radius is provided at the tip of the second magnetic pole 801.

FIG. 4 shows an example of the distribution of the magnetic flux 805 generated by the electromagnet 8. As shown in FIG. 4, due to the shapes of the first magnetic pole 802 and the second magnetic pole 801, a magnetic flux distribution spreading in a cone shape near the electron transmission window 7 is exhibited. The inner diameter of the first magnetic pole 802 is determined by 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. 1, a shield 12 is provided outside the electromagnet 8 to shield X-rays. The irradiation object passage 10 penetrates 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 is rotated by a rotation drive mechanism (not shown). The irradiation object rotary transfer device 150 includes a rotating cylinder 151 and the rotating cylinder 151.
An irradiation target guide 152 made of a helical thin plate attached to the surface of the object and a number of gas outlets 153 provided in the rotating cylinder 151 are included. A gas such as compressed air or compressed nitrogen is supplied to the inside of the rotary cylinder 151, and the gas is ejected from the gas ejection port 153 into the outside irradiation object passage 10 at a high speed. 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 the rotating cylinder 151, and an irradiation target guide 152.
It is transported vertically downward while rolling in a state of being confined in 55. The gas ejected from the gas ejection port 153 at a high speed collides against the granular irradiation target 100 in the spiral space 155 and is rotated at a high speed. In this manner, the irradiation target 100 revolves spirally while rotating at a high speed, and is transported vertically downward.

FIG. 2 shows an enlarged vertical cross section of a part of FIG. 1, and FIG. 3 shows a main part of a cross section viewed from AA 'in FIG. As shown in FIGS. 1 to 3, an irradiation target partition 156 is provided between the irradiation chamber space 111 and the irradiation target passage 10, and the granular irradiation target 100 is disposed in the electron transmission window 7. It does not touch. The irradiation target partition 156 has a number of slits 157 parallel to the central axis Z, and the irradiation chamber space 111 and the irradiation target passage 10 are formed.
Is 80% or more, most of the electrons that fly from the irradiation chamber space 111 pass through the irradiation object passage 10.
And is absorbed by the surface of the irradiation object 100 that passes while rotating. Some of the electrons are absorbed by the irradiation target partition 156 and converted into heat, but the temperature rise is suppressed low by heat conduction of the irradiation target partition 156 and the forced cooling by spraying the high-pressure gas. The irradiation target 100 comes into contact with the irradiation target partition 156 by spraying the high-pressure gas, but the temperature of the irradiation target partition 156 is low and the irradiation target 100 is
So that there is no alteration. Further, since the ring-shaped electron transmission window 7 is disposed orthogonal to the irradiation object passage 10, even if the electron transmission window 7 becomes high in temperature due to the absorption of electrons, the radiant heat reaches the irradiation object 100. It has become difficult. A small amount of heat is applied to the irradiation target 100, and the irradiation target 100 is rotated at high speed and cooled by blowing high-pressure gas, so that the temperature rise can be suppressed to a low level.

The operation of the electron concentrating means for concentrating the electrons transmitted through the electron transmission window 7 in the region within the irradiation object passage 10 will be described below with reference to FIGS. FIG. 5 schematically shows, on an enlarged scale, an annular electron transmission window 7 disposed coaxially perpendicular to the central axis of the irradiation target passage 10. Here, the Z axis coincides with the central axis of the irradiation object passage 10, the lower side of FIG. 1 has positive coordinates, and the R axis represents the radial direction. As shown in FIG. 5, 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, an angle φ in the radial direction is set.
Consider a case in which electrons are incident from an annular groove 602 in a vacuum region inclined at ₀ with respect to the Z axis. The incident electrons decrease in energy and are scattered in the electron transmission window 7, and as shown in FIG. 5, in a plane including the point P ₁ (r ₁ , θ ₁ , z ₁ ) and the Z axis, and at right angles to the plane. The electron beam enters the irradiation room space 111 which is an atmospheric pressure region outside the electron transmission window 7 with a directivity velocity distribution which is three-dimensionally spread in the direction of the surface.

The point P in FIG.₁(R₁, Θ₁, Z₁) And Z axis
FIG. 6A is a cross-sectional view in a plane including
A cross-sectional view in the direction is shown in FIG. 6-a angle
φ₁Indicates the scattering angle of electrons in the RZ plane.
This is called the radial scattering angle. Angle φ in FIG. 6-b₂
Indicates the scattering angle of electrons in a plane perpendicular to the RZ plane.
And is called the lateral scattering angle. 100 KeV exercise energy
Initial speed v with lugie _iAt angle φ₀Just tilted electron
The electrons incident on the transmission window 7 have an energy of about 20 KeV.
And the initial velocity of the transmitted electrons is somewhat reduced.
This is v₀Then, the velocity of the transmitted electron in the R, θ, and Z directions
Component v_r, V_θ, V_zAre v_r= V₀・ Si
n (φ₁−φ₀) · Cos (φ₂), V_θ= -V₀・ C
os (φ₁−φ₀) ・ Sin (φ₂), V_z= V₀・ C
os (φ₁−φ₀) · Cos (φ₂).

Outside the ring-shaped electron transmission window 7, an electron concentration hand
The electromagnet 8 as a step has its central axis coincident with the Z axis
Near the inside of the electron transmission window 7
And on the outside, the magnetic flux density component in the radial direction as shown in FIG.
B_r, Magnetic flux density component B in the Z-axis direction_z805 with magnetic flux
Exists, the electrons entering this region are roughly e (v _z
B_r-V_rB_z) Can be given a rotational force around the central axis
Will be. Where v_zAnd v_rIs the velocity component of the electron in the Z direction.
Minute and R direction velocity components, and e represents elementary charge, respectively.
You. As the electron approaches the electromagnet 8, it gives a strong rotational force.
Each component B of the magnetic flux density_r, B_zGives the spatial distribution of
Keep in mind that electrons move in a positive
Attempts to rotate in the positive direction around the Z axis due to rotational force
You. FIG. 7-a shows an electric rotating in the positive direction around the Z-axis.
Is the magnetic flux density component, B_r, B_zDirection of force received by
Is schematically shown. In this case, the electrons are turned in the positive direction.
While rotating, it is decelerated in the Z-axis direction, and the radius decreases.
You will receive power. FIG. 7-b shows a negative around the Z axis.
The electron rotating in the direction is the magnetic flux density component, B_r, B_zTo
Therefore, the force received is shown. In this case, the electron is the Z axis
Is accelerated in the Z-axis direction while rotating in the negative direction around
It will diverge in the axial direction. Transmission through electron transmission window 7
Velocity v of the electron immediately after_θIs negative in FIG.
If the direction is positive, forward rotation is emphasized, and electrons are
It approaches the Z-axis while receiving the force in the direction. θ direction
Heading speed v_θOrbit deviates from the Z axis due to the effect of
The orbit of the electron is the magnetic flux density component, B_r, B_zIs zero
, The closest distance to the Z-axis is smaller. this
The situation is schematically shown in FIGS.

FIG. 2 shows that the electron is emitted from the annular cathode 2 to which a voltage of -100 KV is applied and is focused with a uniform electron density by the focusing electrode 3 to which approximately -100 KV is applied. An electron beam 701 formed and accelerated by an electron accelerating means comprising an anode structure 4 and an anode ring 5 set to a ground potential travels on a cone-shaped orbit, passes through an annular electron transmission window 7 and has a wavelength of 80 Ke.
The trajectory of the electrons scattered at the lateral scattering angle φ ₂ and the radial scattering angle φ ₁ with the kinetic energy of V is projected on the RZ plane and schematically represented. Point P ₁ (r
₁ , θ ₁ , z ₁ ), the electrons scattered at the radial scattering angle φ ₁ are considered to be ignorable by the effects of scattering in the atmosphere when the electromagnet 8 is not provided as the electron concentrating means. , Do not reach the irradiation target 100 in a straight line as indicated by a broken line 702 ′. However, when the above-described electromagnet 8 is provided, the above-mentioned electron is a magnetic flux density component, B
trajectory 702 deflected by _r , B _z and represented by a solid line
As shown by the arrow, since the vehicle travels at an increased angle with the irradiation target passage 10, the ratio of electrons reaching the irradiation target 100 increases.

In FIG. 3, an annular groove 6 in the vacuum region
A representative example of the trajectory of an electron approaching the electron transmission window 7 through the reference numeral 02 is shown at 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 orbit of the electron thus obtained is schematically shown at 702. When the electromagnet 8 is not provided, that is, when the magnetic flux density B is 0, these electron trajectories 702 proceed substantially in a straight line, ignoring the influence of scattering in the atmosphere, and do not reach the irradiation target. However, as can be seen from FIG. 3, when the magnetic flux density B of the electromagnet 8 is set to an optimum value, the electron trajectory is indicated by 702 by the effect of the electron concentrating means.
It is bent toward zero, and is irradiated on the irradiation target 100. Thus, by providing the electromagnet 8, the closest distance of the electron trajectory to the Z axis can be reduced, so that the electron orbit approaches the outer peripheral surface of the irradiation object passage 10 at an angle approaching perpendicularly, and the electron Accuracy improves. On the other hand, even when the initial velocity vθ in the _θ direction is the positive direction in FIG. 8B, 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 occurs.

[0036] have been described in the electron orbit in a typical operating conditions in the above, there is a similar effect for a case where the energy of the case or a transmission electron radial scattering angle phi ₁ is different or 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 transmission window 7 to the irradiation target 100 is improved as a whole, and the electron density in the electron transmission window 7 can be increased without increasing the electron density. An electron beam irradiation apparatus capable of irradiating the irradiation body 100 with a large amount of electrons 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 can be irradiated in both the direction of the RZ plane and the direction of the Rθ plane. It has been experimentally confirmed that the number of electrons applied to the irradiation target 100 increases approximately 10 times in total because the light is deflected to approach 100. As shown in FIG. 3, a large number of similarly irradiated electrons are irradiated to a large number of irradiated objects 100 from all around the irradiated object passage 10. As described above, since a large number of granular irradiated objects 100 spirally move around the outer peripheral region of the irradiated object passage 10 in the Z-axis direction while rotating at a high speed, the entire surface of each irradiated object 100 Irradiated uniformly. The kinetic energy of the irradiated electrons is 80 Ke
Since it is as low as about V, it is absorbed only on the surface of the irradiation object 100 and does not reach a deep part. Further, since the surface of the electron transmission window 7 is perpendicular to the central axis Z of the irradiation object passage 10, radiant heat from the electron transmission window 7 does not easily reach the irradiation object 100.

Next, the operation and effects of the electron beam irradiation apparatus of the present invention will be further described with reference to examples. The inner diameter of the irradiation target passage is 10 cm, and the electron transmission window 7 has a thickness of 10 μm.
m, an outer diameter of 16 cm, an inner diameter of 12 cm, made up of a circular thin film of titanium, a surface area of 88 cm ² ,
The case where electrons are uniformly spread and incident on this surface will be described. Since the electron incidence density allowed for such a thin film while maintaining reliability is about 20 W / cm ² , the input allowed in this embodiment is 1760 W. When the energy of the incident electron is 100 KeV, 17.6 mA
Current. About 50% of the incident electrons are absorbed by the electron transmission window 7, and about 50% of the remaining electrons are transmitted with a kinetic energy of 80 KeV. The power of the transmitted electrons is 704 W. Irradiated object 100 has a radius of 2.5
mm, and the density is 1.2 g / cm ³ , the depth of penetration of the electron beam is about 40 μm, so that the volume of each part irradiated with the electron beam is 0.0
031cm ³ and the mass of this part is 0.0037g
It is. In the case where the electromagnet 8 is not used as the electron concentrating means, it is assumed that 8% of the power of the transmitted electrons hits the irradiation target 100, and 2K per irradiation target.
If it is necessary to irradiate a dose of Gy,
An object to be irradiated of 5 kg can be processed.

When the above-described electromagnet 8 as the electron concentrating means is attached to give an optimum magnetic flux density, the hit rate on the irradiation target 100 is improved by about 10 times as described above. Is improved to 350 kg per minute. Since the total length of one electron beam irradiation device is about 50 cm, when the devices are connected in series and used,
A dose of 0 can be increased accordingly. For example, when five units are connected in series, the total length of the device becomes 2.5 m, but the irradiation dose of the irradiation object 100 is increased to 20 KGy, and a sufficient irradiation dose can be obtained. If it is necessary to further increase the processing capacity, the area of the electron transmission window 7 is increased to increase the distribution of electrons incident on the electron transmission window 7, and the electron transmission window 7 is kept in a state where the electron density in the electron transmission window 7 is kept low. Can be easily achieved by allowing the transmitted electrons to hit the subject by the electron concentrating means. Broadening the electron distribution can be easily realized by, for example, increasing the bias voltage of the focusing electrode 3 as the electron dispersion means.

In the above embodiments and examples, the electron gun has the annular cathode 2 and its central axis is mounted concentrically with the central axis of the irradiation object passage 10, but has a diameter of 4 mm. Of course, 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 also be divided into a plurality of pieces. Needless to say, the electron transmission window 7 may also be formed in an annular shape with a large number of divided segments.

The irradiation chamber space 111 has an inlet 112 and an outlet 113 for an inert gas. The inert gas is blown onto the electron transmission window 7 to forcibly cool it. Since the inert gas moves in the direction of the irradiation target passage 10 at a high speed, even when fine powder or fluid comes from the irradiation target passage 10, there is an action of pushing them back.
It functions as the above-mentioned irradiation object contact prevention means. It is made of a substance such as aluminum having an atomic number smaller than that of iron so that generation of X-rays is reduced when electrons transmitted through the electron transmission window 7 collide with the wall 11 of the irradiation room space 111.

Next, a modified embodiment will be described with reference to FIG. In FIG. 8, a cylindrical fan-like structure having a slit 157 is employed as a means for preventing contact with an irradiation object, and the blades 158 have an angle with the irradiation chamber space 11.
1, it is rotatably mounted around the irradiation object passage 10. Since the inert gas blown from the electron beam transmission window 7 is rotated at a high pressure by the rotation driving mechanism (not shown) at a high speed in the direction of the arrow 159, the irradiation object passage 1 is rotated.
It is sprayed in 0. When fine particles and fluid are contained in the irradiation object 100, the gas pressure pushes these fine particles and fluid back into the irradiation object passage 10, so that the reliability of the electron transmission window 7 is improved. . When this irradiation target contact preventing means is employed, even if the irradiation target 100 is a fluid such as a toxic gas, the irradiation target 100 is prevented from reaching the electron transmission window 7 and the electron beam irradiation of the present invention is prevented. The device is valid. In addition, in the case where the irradiated object may be damaged by the rotating portion, the problem can be solved by attaching the rotating structure shown in FIG. 8 around the fixed structure having slits shown in FIG.

Although the present invention has been described in connection with the embodiments and examples, the present invention is not limited to the structures and forms of the embodiments and examples illustrated here, but the spirit and scope of the present invention. It should be understood that various embodiments are possible and that various changes and modifications can be made without departing from the scope of the present invention. For example, it goes without saying that the electromagnet 8 as the electron concentration means may be replaced with a permanent magnet. Further, in the present embodiment shown in FIG. 1, the electron transmission window 7 is formed in a circular flat plate shape to make it easy to form, but it is a matter of course that the electron transmission window 7 may be formed in a cone shape. It is a matter of course that the structure as the means for preventing contact with the irradiated object may be in the form of a net. The rotating body as the means for preventing contact with the irradiated object may be provided in parallel with the electron transmission window. A plurality of the same type or different types of irradiation object contact prevention means may be employed. Further, it is natural that the irradiation target may be configured to be moved in the horizontal direction.

As described above, by employing the electron beam irradiation apparatus of the present invention, it is possible to completely cure and modify the resin applied to the surface of a granular object and to sterilize the surface. When irradiating these irradiated objects with an electron beam for the purpose of completely performing over the surface, these processing can be performed in a narrow place without spreading these irradiated objects in a sheet shape. A compact and highly reliable electron beam irradiator that can irradiate the entire surface of a granular object uniformly with an electron beam without applying excessive heat to the entire surface of the object, and can completely process the entire surface of the object. Can be provided. In particular, it is possible to provide an electron beam irradiation apparatus capable of completely sterilizing the surface of a grain with shells by irradiating only the shell portion with an electron beam in a state where the processing speed is increased and without altering the grain. . In the case of these electron beam irradiations, reliability can be ensured because the irradiated object does not approach the electron beam transmission window. Furthermore, since the electron transmission window is attached at an angle to the irradiation target, it is not easily contaminated by evaporation of the irradiation target, and is not only highly reliable, but also has a short overall length and is compact, and is connected to a series. As a result, it is possible to provide an electron beam irradiator with further improved processing ability. It can also be used for the decomposition of toxic gases.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of an electron beam irradiation apparatus according to an embodiment of the present invention.

FIG. 2 is an enlarged view of a part of FIG. 1 which is a longitudinal sectional view of the embodiment of the present invention.

3 is a longitudinal sectional view of an embodiment of the present invention, FIG.
It is the cross-sectional view seen from the arrow direction of A '.

FIG. 4 is a cross-sectional view showing the structure of an electromagnet as an electron concentrating means as a main component of the present invention and the distribution of magnetic flux.

FIG. 5 is a principle diagram for explaining the principle of the present invention, and schematically shows scattering of electrons in an electron transmission window.

FIG. 6 is a principle diagram for explaining the principle of the present invention, and shows an angle relationship of electron scattering in an electron transmission window.

FIG. 7 is a principle diagram for explaining the principle of the present invention, and shows the effect of magnetic flux density on orbiting electrons.

FIG. 8 is a cross-sectional view illustrating a modified embodiment of the present invention.

FIG. 9 is a schematic cross-sectional view of a conventional electron beam irradiation 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 of extension line of cone-shaped electron orbit of electron beam and center line of irradiation object passage 10 10 Irradiated body passage 11 Irradiation chamber wall 12 Shield 13 Insulation cylinder 14 Electron gun mount 15 High voltage lead wire 16 Exhaust pipe 17 Mounting bracket 100 Irradiated body 101 Vacuum space 111 Irradiation room space 112 Gas inlet 113 Gas exhaust Outlet 150 Irradiated object rotary transfer device 151 Rotating cylinder 152 Irradiated object guide 153 Gas ejection port 154 Irradiated object passage inner wall 155 Spiral space 156 Irradiated object partition 157 Slit 158 Blade 401 Electron passing hole 402 One of anode structure 4 Plate portion 405 a large number of radially provided depressions 406 electron passages 601 radially provided multiple Recess 602 annular groove 603 cooling channel 701 electron orbit 702 electron trajectory 702 'electron orbits 801 annular second pole 802 first pole 803 coil 804 magnetic pole 805 like magnetic potential curve of the annular

Claims (13)

[Claims] A vacuum container constituting a vacuum region, an irradiation object passage for passing an irradiation object outside the vacuum container, a cathode for emitting electrons inside the vacuum container, An electron acceleration means for accelerating the electrons emitted from the cathode; an electron transmission window for transmitting the electrons accelerated by the electron acceleration means to the outside of the vacuum vessel; and the object to be irradiated comes into contact with the electron transmission window. An electron beam irradiating apparatus, comprising: an irradiation object contact preventing means for preventing the irradiation. 2. The apparatus according to claim 1, further comprising electron concentrating means for increasing an angle between a traveling direction of the electrons transmitted through the electron transmission window and the passage of the irradiation object. The electron beam irradiation apparatus according to claim 1. 3. The device according to claim 1, wherein the electron transmission window is provided so as to surround the object to be irradiated, and has an angle with the passage of the object to be irradiated. 3. The electron beam irradiation apparatus according to any one of 2. 4. A structure in which the irradiation object contact preventing means has a hole or a slit having an opening smaller than the width of the irradiation object between the electron transmission window and the irradiation object passage. The electron beam irradiation apparatus according to any one of claims 1 to 3, wherein the electron beam irradiation apparatus is configured to include a body. 5. The illuminated body contact preventing means is characterized in that a rotating body having an opening is provided between the electron transmission window and the illuminated body passage. The electron beam irradiation apparatus according to claim 1. 6. The apparatus according to claim 1, wherein said irradiation object contact preventing means includes a mechanism for flowing a fluid in a direction of pushing said irradiation object back to said irradiation object passage.
The electron beam irradiation apparatus according to any one of the above. 7. The irradiation object passage is formed in a cylindrical shape, the irradiation object moves close to the outer periphery of the irradiation object passage, and the accelerated electrons are irradiated with the irradiation light. The electron beam irradiation apparatus according to claim 1, wherein the irradiation is performed from around the body passage toward the irradiation target. 8. An electron beam according to claim 1, wherein an irradiation object rotating means for rotating the irradiation object is provided in the irradiation object passage. Irradiation device. 9. The electronic device according to claim 1, further comprising means for helically moving the irradiation object placed in the irradiation object passage. Line irradiation equipment. 10. The apparatus according to claim 1, wherein at least one of the surfaces constituting the passage of the irradiation object is mechanically vibrated, rotated or moved.
The electron beam irradiation apparatus according to any one of the above. 11. The apparatus according to claim 1, wherein a fluid is sprayed from at least one of the surfaces constituting the irradiation object passage to the irradiation object to rotate the irradiation object. The electron beam irradiation apparatus according to any one of 1 to 10. 12. The electron beam irradiation apparatus according to claim 3, wherein said electron transmission window is formed substantially orthogonal to said irradiation object passage. 13. The method according to claim 1, wherein a trajectory of electrons incident on the electron transmission window forms an acute angle with a direction in which the irradiation object moves. Electron beam irradiation equipment.