JP3822426B2 - Electron beam irradiation device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a mechanism for suppressing ozone generation in a sterilization treatment of a granular material by an electron beam irradiation apparatus. The electron beam irradiation apparatus generates thermoelectrons in a vacuum and accelerates them to form electron beams through the window foil into the atmosphere and irradiates the object to be processed for various processing. In order to generate an electron beam, it has a vacuum chamber, a hot filament, a filament power supply, an acceleration (high voltage) power supply, and the like. There are devices that scan an electron beam and devices that do not. In the case of the scanning type, there is a scanning device following the electron beam generator. This consists of a triangular scanning tube and a scanning coil. In the case of the non-scanning type, there is no scanning device. The space between the vacuum chamber and the atmosphere is called an irradiation window. Although the irradiation window is an opening, a window foil is stretched to block atmospheric pressure and vacuum.
[0002]
The purpose and action of processing differ depending on the acceleration energy. Conventionally, it has often been used to promote polymer reactions such as cross-linking of electric wire coating. This often accelerated the electron beam with relatively high energy because the electron beam entered inside. In addition, it may be used for curing printed materials, coating films, and plastic coatings. Depending on the thickness, the energy for curing these coatings and coatings is relatively low. It may also be used for sterilization of medical tools and medical materials. Also in the case of sterilization, the required energy differs depending on the desired penetration depth depending on the object.
[0003]
When handling high-energy electron beams, scanning is often performed with a narrow beam. In the case of low energy, a non-scanning type that suddenly produces a beam with a large effective area is often used.
[0004]
In any case, conventionally, a large-sized solid was a workpiece. Recently, however, attempts have been made to use it for sterilization of foods such as grains and spices. Usually, foodstuffs are not sterilized. However, imported grains and raw ingredients should be sterilized. In some cases, grains, spices, etc. were purified with gases such as methyl bromide and ethylene oxide. It is killed by gaseous chemicals. Treatment with toxic chemicals is not always preferred due to residual gas problems.
[0005]
Therefore, harmless electron beam processing is expected as a promising technology. Electron beams have a bactericidal action, and there are already proven results in medical-use standard instruments and materials. I want to apply electron beam sterilization technology to foods. However, there are a number of problems, and electron beam sterilization of food materials has not yet been put into practical use.
[0006]
First, there is a cost problem. Since a large amount of processing cannot be performed, the cost becomes high. Grain and spices are extremely small particles, and the part to be sterilized is limited to the surface layer. Only the surface of the particulate food material needs to be sterilized. The difficulty is not that the electron beam does not need to enter the interior but that the electron beam must not enter the interior. When the electron beam reaches the inside of cereals and spices, it denatures the internal carbohydrates and proteins. Because of this, the flavor drops significantly. There is also a possibility that the value as a food will fall and it will become impossible to sell. Irradiate by generating an electron beam of weak energy that only stays on the surface. A thin particle is piled up on the transport system, and the electron beam is applied evenly to only the surface layer of all the particles while rolling up and rotating. It's easy to say but difficult in practice. Since only the surface layer is irradiated with an electron beam, a lot of things cannot be stacked on the transport system. When stacked in multiple layers, the lower layer becomes unirradiated. This may hinder cost savings.
[0007]
Although it is difficult to apply an electron beam only to the surface layer while rotating the granule, it is not touched here. The present invention addresses another problem. Under the irradiation window is atmospheric pressure and there is air. When an electron beam hits a solid such as a transport system or an object to be processed, it loses energy and changes to heat. The electron beam generates X-rays when the inner electrons of the atoms constituting the carrier system and the target object are excited to return to the original state. Since this X-ray is harmful, the transport system must have a strict X-ray blocking structure. Therefore, the transport system is covered with a thick metal casing. This is also a problem, but the present invention does not address this. Even if X-rays do not leak outside, there is still a problem. An object is heated by an electron beam or X-ray in an oxygen atmosphere. In the case of foodstuffs such as powder, it may be ignited by heat. In the presence of oxygen, combustion continues and there is a possibility of explosion. Even more troublesome is that X-rays excite oxygen to generate ozone. X-rays have high energy and can make ozone from oxygen.
[0008]
When ozone is generated, there is a problem that it is harmful in itself and damages the working environment. When the object is food, there is a problem that ozone odor adheres to the food as well. The smell of ozone is intense and significantly impairs the flavor. Ozone generation must be strictly controlled. The present invention makes this a problem.
[0009]
[Prior art]
Ozone is generated because it contains oxygen. Because of the air atmosphere, ozone is generated by X-rays. In the case of an object which dislikes ozone, electron beam irradiation is performed in a state where nitrogen or an inert gas is forcibly blown to expel oxygen. This is the same when a conventional tangible solid is used as a workpiece. However, unlike the case of a conventional large-sized solid, there are special new difficulties in the case of granules as food materials.
[0010]
In the case of a large solid, the oxygen attached to the solid was stripped off and easily replaced with nitrogen by blowing nitrogen gas on the object to be processed from near the irradiation window. Therefore, there are a nitrogen gas blowing port and a drawing port before and after the irradiation window of the electron beam irradiation apparatus. Nitrogen is blown backflow from the downstream side to peel off oxygen from the object to be treated and surrounded with nitrogen. He was exposed to an electron beam surrounded by nitrogen. The mixed gas of oxygen and nitrogen is drawn out from the upstream gas outlet.
[0011]
The reason that the gas is made opposite to the movement of the transport system so that the gas flows backward is to push back the oxygen so as not to reach the irradiation window. Therefore, the gas outlet must be before the irradiation window.
[0012]
There is still a reason. This is to make gas replacement easier by increasing the relative speed and extending the contact time. When the speed of the transport system (endless circular conveyor) is U and the gas flow velocity is V, the relative speed at which the gas hits the workpiece that is a tangible solid is (U + V). The length of the part where a certain gas contacts the object to be processed is not equal to the distance L from the gas inlet to the gas outlet. Instead, it is L (V + U) / V. In other words, the gas flow is reversed to increase the collision speed and increase the residence time. If gas flows in the same direction as the transport system, the relative velocity decreases to (U−V) and the contact length also decreases to L (V−U) / V. In the electron beam irradiation apparatus, the back flow of nitrogen gas has been practiced for a long time, but this is also devised.
[0013]
When the large-sized solid is an object to be treated, gas flow replacement proceeds promptly because the effective surface area is narrow and the surface is open. Therefore, it is possible to replace the gas simply by providing a nitrogen gas blowing port / drawing port near the irradiation window so that nitrogen gas (or inert gas) is blown onto the object to be processed. When oxygen is stripped from the object to be processed and replaced with nitrogen, ozone is not generated even if X-rays are generated by receiving an electron beam. That was fine when the large solid was a workpiece.
[0014]
FIG. 1 is a schematic configuration diagram of an electron beam irradiation apparatus first considered by the present inventors for particle processing. FIG. 2 is a part of an xx cross-sectional view of FIG. This is a trial experiment apparatus of the present inventors, and is not a known apparatus. It differs from conventional ones that target fixed solids in the transport path and transport mechanism. This shows a non-scanning electron beam irradiation apparatus.
[0015]
The inside of the cylindrical vacuum chamber 1 for generating an electron beam is evacuated. A concentric cylindrical cathode shield 2 is in the vacuum chamber 1 and a filament 3 is provided. The filament 3 is heated by an electric current. The heated filament 3 generates thermoelectrons. This is accelerated to an electron beam 4 by the acceleration voltage. The lower opening of the vacuum chamber 1 is an irradiation window 5. An apparatus for transporting an object to be processed is surrounded by a thick metal casing for shielding X-rays, but the shielding structure such as the casing is not shown here.
[0016]
In the case of granules, it is necessary to apply an electron beam only to the surface layer. For this purpose, the vibratory conveyor 7 is used for the transport mechanism because it is necessary to raise and rotate the particles. The vibrating conveyor 7 conveys particles on the plate in one direction by applying an asymmetric reciprocating motion to the horizontal plate. The vibration generator 8 is a device that generates vibrations directed obliquely forward. The spring 9 elastically supports the plate portion of the vibration conveyor 7. By elastically supporting, the plate portion can freely vibrate. The declination in front of the angle is 45 ° here. Even if the plate is horizontal, the particles placed on it can advance while jumping up. The vibration generator can generate vibration by rotating an eccentric flywheel, for example. In addition, the weight can be reciprocated in an oblique direction to generate vibration by a reaction. The amplitude and frequency can be freely changed by the vibration generator.
[0017]
The conveyance path is composed of an input path 10 provided on the vibration conveyor 7, a horizontal path 11 that follows, and a discharge path 12 that follows. These are closed spaces through which the particles that are the objects to be processed pass. The irradiation unit 13 in the middle of the horizontal path 11 receives an electron beam process. The irradiation unit 13 is a portion directly below the irradiation window 5. The electron beam 5 emitted from the filament 3 passes through the window foil 6 and enters the atmosphere, hits the particle S in the irradiation unit 13, and sterilizes the particle S. The conveyance path of the vibration conveyor 7 vibrates. Care must be taken when connecting to a fixed conveyance path that does not vibrate. The flanges of the fixed conveying path and the upstream side of the vibrating conveyor are not fixed to each other, and are relatively movable to some extent, so that the outer side is surrounded by the canvas 14. The reason for enclosing with canvas 14 is to confine gas and particles. The flanges are not fixed to the fixed conveyance path and the connecting portion on the downstream side of the vibrating conveyor. A certain amount of relative movement is possible. The outside is surrounded by the canvas 16. The boundary between the vacuum chamber 1 and the vibrating conveyor is also coupled so as to be able to move relatively. The canvas 15 is also wound here. Such a flexible coupling structure allows microvibration of the vibratory conveyor.
[0018]
When the granules S to be food such as cereals are put into the feeding path 10, an air film is attached to the surface. Since air contains oxygen, ozone is produced when it receives an electron beam as it is. That is a problem. Therefore, a gas inlet 17 is provided downstream of the irradiation unit 13 in the horizontal path 11 of the transport system. To this, an inlet side flexible tube 18 is connected to supply nitrogen gas or inert gas (argon, neon, helium, etc.). A gas outlet 19 is provided upstream of the irradiation unit 13 in the horizontal path 11. An outlet-side flexible tube 20 is connected to the gas outlet 19. Nitrogen gas is introduced into the transport system from the gas inlet 17 on the downstream side, passes back through the granules, reaches the gas outlet 19 while being stripped of oxygen gas, and is removed from the flexible tube 20.
[0019]
The reason for reversing is that oxygen does not go to the irradiation section 13 as described above, and that the impact of contact is increased and the contact portion is lengthened. In this way, oxygen can be removed by reversing nitrogen gas in the horizontal path. Even in the case of a large tangible solid, gas is blown in from the downstream side and gas is taken out from the upstream side. However, the gas inlet is shifted to the downstream side longer than in such a case, and the gas outlet is pulled up to the upstream side. That is, the interval between the gas inlet and outlet is made longer than that in the case of a conventional large-sized solid. This is to increase the chance of replacing oxygen by increasing the contact time.
[0020]
[Problems to be solved by the invention]
The apparatus shown in FIG. 1 has been produced and tested by the inventor, but is not known. Although the interval between the gas inlet and outlet is lengthened, this is an extension of the conventional tangible solid object in that the gas inlet and outlet are provided across the irradiation window to reverse the gas and replace oxygen. I experimented with making such a new device, but it turned out that it was still not enough for fine particles like food. Grain grains are so small that they cause a completely different problem from that of conventional solid solids. When small particles like cereals are folded and present, the effective surface area is large and the gas flow path is narrow, so gas replacement is difficult.
[0021]
The oxygen gas adhering to the grain particles cannot be easily removed by spraying the gas from the outside. In some cases, the particles form large lumps that prevent nitrogen from entering the interior. It is difficult to break up the lump. For this reason, oxygen adheres to fine particles having an effective surface area, and oxygen comes to the irradiated portion. The oxygen concentration in the irradiated area is not sufficiently lowered by the oxygen brought in by the granular material. There are a number of problems when oxygen is brought into the irradiated area.
[0022]
When powder particles accumulate on the irradiated area, they are heated by electron beams, so there is a danger of ignition if oxygen is present. There is also the possibility of igniting and burning the grain. It is dangerous.
[0023]
If the oxygen concentration does not decrease sufficiently, oxygen is excited by X-rays and ozone is generated. Ozone is highly corrosive and oxidative and harmful, and it is dangerous to leak outside. But the harm of ozone doesn't stop there. When the object to be processed is a food, an odor of ozone is attached. The ozone odor is intense and reduces appetite. I can't eat anything with an ozone smell. In other words, ozone significantly impairs the flavor of food.
[0024]
If the object being transported is powder or granules, oxygen cannot be easily removed. In a nitrogen exchange system in which nitrogen is blown immediately after the irradiation window and nitrogen is withdrawn immediately before, the oxygen cannot be completely removed.
[0025]
It is an object of the present invention to provide an apparatus capable of completely removing oxygen and replacing it with nitrogen or an inert gas even when the object to be processed has a large effective surface such as a granule or powder. .
[0026]
[Means for Solving the Problems]
A part of the conveying path upstream of the irradiation part is provided with a dispersing structure for reducing the speed of the granular material and dispersing the granular material, and a suction port for sucking gas is provided very close to the structural object. Oxygen which a granular material brings into the irradiation part of an electron beam irradiation apparatus in a part of the upstream of a conveyance path | route is reduced efficiently.
[0027]
That is, in the present invention, in order to process the processed object of the granular material and the granular material, upstream of the irradiation part of the transport system of the electron beam irradiation apparatus (1) Dispersion structure (shielding material) for reducing the flow velocity of the granular material
(2) A new exhaust port for sucking the replacement gas of the oxygen adhering to the granules provided near the dispersion structure is provided to eliminate oxygen brought into the irradiation section.
[0028]
DETAILED DESCRIPTION OF THE INVENTION
The electron beam irradiation apparatus of the present invention will be described with reference to FIG. This is because the dispersion structure for reducing the speed of the particles and dispersing the particles on the particle input path side of the apparatus experimentally tested by the inventor shown in FIG. 1 and the suction port for sucking the gas are provided. Newly provided. The other structure is the same as that of FIG.
[0029]
The horizontal cylindrical vacuum chamber 1 and the cathode shield 2 have a concentric structure. A filament 3 is provided in the cathode shield 2. A high negative voltage is applied to the filament. An electron beam 4 is generated from the filament by passing a filament current. An opening in the lower bottom portion of the vacuum chamber 1 serves as an irradiation window 5, and a window foil 6 is provided to separate atmospheric pressure and vacuum. The electron beam 4 generated in vacuum proceeds toward the irradiation window 5 and exits into the atmosphere through the window foil 6.
[0030]
An oscillating conveyor 7 is provided in order to carry the particles S to be processed in one direction. The vibration conveyor 7 pushes particles on the plate in one direction by applying asymmetric vibration to the horizontal or forward inclined plate. The vibration conveyor 7 includes a vibration generator 8 mounted immediately below a horizontal plate, and a spring 9 that holds the plate so as to vibrate. The vibration generator 8 is a device that generates vibration by rotating an eccentric flywheel by a motor, for example. The direction of vibration is a 45 ° front upper diagonal direction. Such vibration can feed the particles on the horizontal plate forward. When a large tangible solid is an object to be treated, an endless conveyor is used, but here the vibratory conveyor is used for the particles. This is to make it hit thinly. Since the entire circumference of the surface has to be sterilized by hitting an electron beam, a static orbiting conveyor is not suitable for the treatment of particles.
[0031]
The transport system includes a vertical input path 10, followed by a horizontal horizontal path 11, followed by a vertical discharge path 12. In the conveyance system, the workpiece is lowered by gravity in the vertical part, but the horizontal part is sent up by the lifting up action by the vibrating conveyor.
The vibrating conveyor 7 and the mechanism of the fixed part are loosely coupled so as not to disturb the vibration of the vibrating conveyor. The flange of the joint portion of the upstream charging path 10 is loosely coupled and the outer periphery is covered with the canvas 14. Since the vacuum chamber 1 is fixed, the coupling between the irradiation window 5 and the horizontal conveyance path 11 is also loosely coupled, and the joint is gently covered with the canvas 15. The flange of the coupling portion of the downstream discharge path 12 is also loosely coupled and the outer periphery is covered with the canvas 16.
[0032]
There is a gas inlet 17 downstream of the irradiation window of the horizontal conveyance path 11. The inlet side flexible tube 18 is connected to this. Nitrogen gas (or inert gas) is blown from here into the inside of the conveyance path. The gas flows from the downstream side to the upstream side as opposed to the flow of the particles. There is a gas outlet 19 upstream of the irradiation window of the horizontal conveyance path 11. The outlet side flexible tube 20 is connected to this. Part of the aforementioned gas is exhausted from here. The above configuration is the same as that of FIG.
[0033]
The novel device of the present invention will be described below with reference to FIGS. It is a device in the charging path 10. A downwardly inclined truncated cone shaped diaphragm plate 30 is provided in the middle of the charging path 10. A central portion of the diaphragm plate 30 is a through hole 31 through which a workpiece is passed. Immediately below the diaphragm plate 30, an upward conical dispersion plate 32 is provided by radial support pins 33. The diaphragm plate 30 and the dispersion plate 32 are referred to as a dispersion structure 36.
[0034]
4 is a cross-sectional view of a portion of the dispersion structure 36, FIG. 5 is a plan view, and FIG. 6 is a longitudinal perspective view. The object to be processed S such as grain falls as a lump or the like, but the particles that have fallen on the periphery collide with the first inverted truncated cone-shaped diaphragm plate 30. The lump is pulverized by impact force and becomes fine particles. The pulverized granules are moved toward the center by inclination and fall through the through holes 31. What dropped from the through hole 31 collides with the conical dispersion plate 32. What was a lump is crushed and made fine. Since the periphery of the dispersion plate 32 is only supported by the support pins 33, the particles S immediately fall from the dispersion plate 32. The dispersion plate 32 and the diaphragm plate 30 are referred to as a dispersion structure 36.
[0035]
The granules S that have fallen from the center in the introduction path 10 do not hit the diaphragm plate 30 but pass through the through holes 31 but are directly dispersed by the direct impact on the dispersion plate 32 directly below. That is, since the granule S always collides with the dispersion structure 36 in which the diaphragm plate 30 and the dispersion plate 32 are combined, the lump is dispersed into fine independent particles.
[0036]
In this example, the diaphragm plate is on the top and the dispersion plate is on the bottom, but this may be reversed. It is only necessary that the plate portions overlap each other when viewed from above so that the particles falling from above collide with each other. The diaphragm plate and the dispersion plate are not limited to one. Two or three aperture plates and dispersion plates may be provided above and below.
[0037]
The dispersion plate is not necessarily a straight cone. For example, the shape may be an impeller. In that case, the diaphragm plate also has a reverse impeller shape. The dispersion plate may be rotatable around the vertical axis. If it is a shape like a horizontal wind turbine, the dispersion force can be strengthened by hitting the granule by the rotational force. In short, it is only necessary to provide two or three or more complementary plates as seen from the top of the charging path.
[0038]
Further, a gas outlet 34 is newly provided between the diaphragm plate 31 and the dispersion plate 32. A flexible tube 35 on the outlet side is connected to the gas outlet 34. Nitrogen gas is also drawn from here. In the dispersion structure 36, the lump of particles is pulverized and the oxygen adhering to the inside is exposed to the outside. Nitrogen gas attacks and peels it off so that nitrogen gas adheres to the particles. Nitrogen gas (or inert gas) is introduced into the conveyance path from the gas inlet 17 on the downstream side of the irradiation unit. This gas travels upstream, opposite to the direction of travel of the granules, and part of it exits from a gas outlet 19 in the immediate vicinity of the irradiation window. However, the remaining gas reaches the gas outlet 34 near the dispersion structure 36. In some cases, the gas outlet 19 may be closed. Compared with the apparatus of FIG. 1, the gas flow path extends from the gas outlet 19 to the gas outlet 34. Since there is a long path from the gas inlet 17 to the gas outlet 34, any oxygen in the middle of the gas inlet 17 is always replaced by nitrogen.
[0039]
Since the gas is extracted around the dispersion structure 36, residual oxygen is also extracted here. In this way, since the gas outlet and the dispersion structure are provided in the charging path, oxygen is deprived from the granular material at the initial stage of charging, and becomes a granular body surrounded by nitrogen and enters the conveying path. There are two advantages of providing the gas outlet 34 in the first input path. One is that the contact time between the granule and the nitrogen can be extended because the distance from the downstream gas inlet 17 to the gas outlet 34 of the charging section is long. The other is that the gas at the moment when the lump is crushed by the dispersive structure (squeezing plate and dispersive plate) can be extracted effectively.
[0040]
When reaching the irradiation part, the particles are irradiated with an electron beam and sterilized. X-rays are emitted by the electron beam, but ozone is not generated because there is no oxygen. Since ozone is not generated, the problem of odor that impairs the flavor is eliminated. It is an invention of an excellent device.
[0041]
【Example】
The present invention is characterized in that the gas outlet 34 and the dispersion structure 36 are provided in the charging path. The falling granule is brought to the center by the squeezing plate, and the granule mass is dispersed by the dispersing plate. When dispersed, the internal gas scatters and the speed decreases, so that the attached oxygen and internal oxygen can be effectively captured and removed to the outside.
[0042]
In order to make it more effective, the dispersion plate 32 or the combination of the dispersion plate 32 and the diaphragm plate 30 may be increased to two or three stages.
[0043]
It is also effective to increase the number of gas outlets 34 and flexible tubes 35. Tests were conducted under the following conditions for a dispersion structure as shown in FIG. 3 having a gas outlet and a case without a dispersion structure as shown in FIG. Although it is the structure of FIG. 3, the gas outlet 19 near the irradiation window and the flexible tube 20 were closed. Nitrogen gas was introduced from the gas inlet 17, and the gas was discharged from the gas outlet 34 of the charging path.
[0044]
○ Test condition input path φ150 tube diffusion plate φ100
Wheat grain 500kg / hr input [0045]
Nitrogen was supplied at 60 Nm ³ / hr from the gas inlet 17 on the downstream side of the irradiation section. In the case of the present invention shown in FIG. 3, nitrogen gas was drawn from the gas outlet 34 of the charging path. In the apparatus of FIG. 1, nitrogen gas is drawn from the gas outlet 19. In such a state, the oxygen concentration in the irradiation unit 13 was measured.
[0046]
Electron beam irradiation device Irradiation part oxygen concentration Device shown in FIG. 3 (the outlet 19 is closed and only the outlet 34 is exhausted) 180 to 220 ppm
1 (exhaust from outlet 19) 1000 ppm or more
In the case of the apparatus shown in FIG. 1, the oxygen gas concentration in the irradiation section exceeds 1000 ppm. This is a fairly large oxygen ratio. In the case of cereals, the upper limit of the allowable oxygen concentration is 500 ppm. In the case of the apparatus in FIG. Therefore, an electron beam irradiation apparatus cannot be used for food processing. In the case of the present invention, since it could be lowered to 180 to 220 ppm, an electron beam can be used for grain processing.
[0048]
【The invention's effect】
In the case of grains and granules like grains, it is difficult to remove oxygen adhering to the outside. When an electron beam is irradiated to an object to be treated with oxygen, ozone is generated and harmful, the flavor is significantly deteriorated, and the value as a food is reduced. In addition, when a processing object containing oxygen is irradiated with a strong electron beam, it may be heated and ignite. In the present invention, a dispersion structure is provided in the charging path, the falling speed of the granules is reduced, the lump is crushed, the internal oxygen is replaced with nitrogen, and the gas is extracted from the gas outlet. Almost no oxygen is present in the irradiated area. Since there is no oxygen, there is no risk of ignition. Ozone generation is reduced because there is almost no oxygen. Since ozone is not attached to the object to be treated, there is no ozone smell and the flavor is not impaired.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of an electron beam irradiation apparatus that the present inventor previously made and experimented for sterilization of grains such as grains.
FIG. 2 is a sectional view taken along line xx of FIG.
FIG. 3 is a schematic configuration diagram of an electron beam irradiation apparatus according to an embodiment of the present invention devised for sterilization treatment of grains such as grains.
4 is an enlarged cross-sectional view of a portion of a dispersion structure provided in a charging path of the apparatus of FIG.
5 is a cross-sectional view of a dispersion plate of the dispersion structure shown in FIG.
6 is an enlarged vertical perspective view of a portion of a dispersion structure provided in a charging path of the apparatus of FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Vacuum chamber 2 Cathode shield 3 Filament 4 Electron beam 5 Irradiation window 6 Window foil 7 Vibrating conveyor 8 Vibration generator 9 Spring 10 Input path 11 Horizontal path 12 Discharge path 13 Irradiation part 14 Canvas 15 Canvas 16 Canvas 17 Gas inlet 18 Inlet side Flexible tube 19 Gas outlet 20 Outlet side flexible tube 30 Diaphragm plate 31 Through hole 32 Dispersion plate 33 Support pin 34 Gas outlet 35 Flexible tube 36 for outlet Dispersion structure S Granule

Claims (1)

In an electron beam irradiation apparatus for processing powder particles, a gas inlet for blowing nitrogen gas is provided on the downstream side of the electron beam irradiation window, and a dispersion structure that disperses the powder particles is installed in the powder particle introduction path. An electron beam irradiation apparatus characterized in that a gas outlet is provided in the vicinity of an object, whereby nitrogen is exhausted to reduce oxygen brought into the electron beam irradiation part by the powder.

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