JP4228187B2 - Electron beam irradiation device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention mainly relates to an electron beam emitting apparatus for generating and utilizing high energy electrons, and more particularly to an electron beam irradiation apparatus using an electron beam emitting tube with a relatively small and low output cooling mechanism.
[0002]
[Prior art]
Electron beam irradiation devices are generally those with an acceleration voltage of 150 kV or more and an electron irradiation window area of 80 cm ² or more. However, in recent years, targeting a low acceleration voltage region with an acceleration voltage of about 50 kV, a small electron beam emission tube emits electrons. An electron beam irradiation apparatus that uses one or a plurality of units has been developed. An electron beam irradiation apparatus using an electron beam emission tube has a feature that maintenance work can be simplified because the electron beam emission tube can be exchanged as a unit in the event of a failure or periodic maintenance inspection, unlike a conventional large apparatus.
[0003]
An electron beam irradiation apparatus using an electron beam emission tube is configured as shown in FIG. 5, for example. Electrons composed of a head portion 52 having an irradiation window 51 made of a material that transmits an electron beam, and a body portion 54 that is provided with an electron generating portion 53 at a position facing the head portion and is made of an electrically insulating material. A beam emission tube 50 is attached to the electron beam irradiation device 70. Reference numeral 59 denotes a casing, in which an insulating liquid or gas such as insulating oil is enclosed in order to prevent the body portion 54 from being charged. Electrons generated by the electron generator 53 are accelerated, pass through the irradiation window 51, and are irradiated to the irradiation object 74 on the conveyor 73. At this time, X-rays are generated not only from the irradiation window 51 and the object to be irradiated 74 but also from the material hit by the electrons. Therefore, the region irradiated with the electrons is surrounded by an X-ray shielding wall 71 such as a thick metal plate to shield the X-rays. Region 72 is designated.
[0004]
The head portion 52 of the electron beam emission tube 50 is provided with a vacuum pipe connection port 57 for keeping the inside of the electron beam emission tube at a high vacuum, and is connected to an external vacuum pipe 58. The external vacuum pipe 58 is connected to an exhaust device (not shown) installed outside the apparatus through a labyrinth portion 63 provided in a part of the X-ray shielding wall 71. An air cooling body 60 for cooling the irradiation window 51 is attached to the irradiation window 51, and is connected from the cooling gas introduction port 55 to the external cooling gas pipe 56 through the X-ray shielding area internal pipe 61 and the intermediate joint 62. Although not shown, when the head main body 66 is water-cooled, a water supply port and a drain port are further provided, and means for taking out the water supply and drainage piping from the X-ray shielding region 72 to the outside is required.
[0005]
When removing the electron beam emission tube in the above electron beam irradiation apparatus, after stopping the apparatus, the lid of the X-ray shielding wall is opened, and after removing each pipe, the entire electron beam emission tube is removed.
[0006]
[Problems to be solved by the invention]
As described above, in the conventional electron beam irradiation apparatus, the piping connected to the electron beam emission tube is inside the X-ray shielding area, and a part of the X-ray shielding wall is required to bring these piping to the outside. As a labyrinth structure, it is necessary to provide an opening for preventing X-rays from leaking to the outside, or to provide an intermediate joint on the X-ray shielding wall to remove the pipe inside the X-ray shielding area. In either case, the design and manufacture of the X-ray shielding area becomes complicated, and the cost of the electron beam irradiation apparatus increases. Also, the procedure is complicated when removing the electron beam emission tube.
[0007]
The present invention was invented in view of the above-mentioned points, and the range in which the electron beam and the X-ray hit can be limited to prevent the apparatus from being deteriorated. Further, the design and manufacture can be simplified. An object of the present invention is to provide an electron beam irradiation apparatus having effects such as ease of performance.
[0008]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, in the present invention according to claim 1, a head part having an irradiation window made of a material that transmits an electron beam, and an electron generation part are installed in a position facing the head part to electrically An electron beam emitting tube composed of a body portion made of an electrically insulating material and an opening for attaching the electron beam emitting tube, surrounding an area where electron beam irradiation is performed, and during electron beam irradiation An electron beam irradiation apparatus comprising: an X-ray shielding area that is separated by an X-ray shielding wall that shields generated X-rays; a vacuum pipe connection port for maintaining a high vacuum inside the electron beam emission tube, and an electron beam emission tube The cooling gas inlet for cooling the irradiation window is provided at a location located outside the X-ray shielding area .
[0009]
In the present invention described in claim 1,
The head portion is
An air cooling body that also serves as a pressing body that incorporates an air cooling path through which a cooling gas for cooling the irradiation window flows, and presses and fixes the irradiation window;
The air cooling body is fastened to the irradiation window side end portion, and a cooling gas introduction port for cooling the irradiation window and a vacuum pipe connection port for keeping the inside of the electron beam emission tube at a high vacuum are provided on the side surface. A head body incorporating a continuous air cooling path from the cooling gas inlet;
Consisting of
By fastening the air cooling body to the head body,
At the same time that the irradiation window is hermetically fixed to the head part,
A continuous air cooling path from the cooling gas inlet to the irradiation window through a connecting pipe having a rigid inner wall and an airtight body provided on the outer periphery of the inner wall is configured in the head portion. It is.
[0010]
According to the first aspect of the present invention, the cooling gas piping of the electron beam emission tube is not affected by the electron irradiation, and the piping routing does not interfere with the X-ray shielding. When exchanging the electron beam emitting tube, it is possible to perform all operations such as pipe removal outside the X-ray shielding area, and the workability is greatly improved.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be described below with reference to FIGS.
FIG. 1 is a schematic front view of an embodiment of the present invention. 1 and 2, reference numeral 10 denotes an electron beam emission tube, which is attached to the upper part of the electron beam irradiation apparatus 30. Reference numeral 11 denotes an irradiation window, which irradiates the electron beam emission tube outside the electron beam emission tube generated and accelerated by the electron generation unit 13 provided in the body unit 14. Reference numeral 12 denotes a head portion, and reference numeral 26 denotes a head body. The irradiation window 11 is attached to one end of the head main body 26, and the cooling gas introduction port 15 and the vacuum pipe connection port 17 are provided on the side surface thereof. An external cooling gas pipe 16 is connected to the cooling gas introduction port 15, and an external vacuum pipe 18 is connected to the vacuum pipe connection port 17.
[0012]
Reference numeral 19 denotes a casing, in which an insulating liquid or gas such as insulating oil is enclosed in order to prevent the body portion 14 from being charged.
[0013]
Reference numeral 20 denotes an air cooling body, which has a built-in mechanism for cooling the irradiation window. Reference numeral 21 denotes a connection pipe, which connects a flow path for introducing a cooling gas from the head body 26 to the air cooling body 20.
[0014]
Cooling body 20 in the embodiment of FIG. 1 has to fit a function to fix the irradiation window 11, air cooling body 20 is elastically deformed by tightening wearing cooling body 20 to the head body 26 occurs when the The irradiation window 11 is pressed against the head main body 26 by stress to be sealed and fixed .
[0015]
Reference numeral 31 denotes an X-ray shielding wall, which surrounds an area where electron beam irradiation is performed inside , and functions to shield X-rays generated during electron beam irradiation. The head portion 12 of the electron beam emission tube 10 is attached to the opening of the X-ray shielding wall 31, and the electron beam irradiation is performed under the irradiation window 11 while moving the irradiation object 34 on the conveyor 33. An area delimited by the X-ray shielding wall 31 forms an X-ray shielding area 32.
[0016]
FIG. 2 is a schematic view showing a state in which the electron beam emitting tube and the external piping are removed in the embodiment of FIG. 1, and all the reference numerals used are the same as those in FIG.
[0017]
FIG. 3 is a schematic view of an embodiment of a connecting pipe portion in the present invention . In FIG. 3, 20 is an air-cooled body and 21 is a connecting pipe, which is the same as that shown in FIG. The opening 29 formed by the tapered portion 24 and the parallel portion 25 of the air-cooled body 20 is open to the surface of the air-cooled body 20 that faces the head main body 26 when fastened to the head main body 26. Reference numeral 22 denotes an inner wall, which is a part or a part of a part constituting a part in contact with the cooling gas passing through the connection pipe 21. Reference numeral 23 denotes an airtight body that is provided on the outer periphery of the inner wall 22 and is a component that contacts the tapered portion 24 and the parallel portion 25 of the opening 29 and hermetically seals the cooling gas. In this embodiment, the above function is realized by covering a normal stainless steel pipe with a rubber tube as an airtight body .
[0018]
FIG. 4 is a schematic view of another connecting pipe portion embodiment of the present invention . In FIG. 4, 40 is an air cooling body, 41 is a connecting pipe, 42 is an inner wall, 43 is an airtight body, 44 is a tapered portion, 45 is a parallel portion, 47 is a cooling gas flow path, 48 is a gas blowing port, and 49 is an opening portion. , and the one shown in FIGS 3 and the shape is different part, has the same function. In this embodiment, an O-ring groove is formed in the pipe, and the O-ring is used as an airtight body.
[0019]
The operation of the electron beam irradiation apparatus according to the present invention will be described below.
In the electron beam irradiation device 30, the boundary of the X-ray shielding area 32 to which the head portion 12 of the electron beam emission tube 10 is attached is provided in the vicinity of the irradiation window 11, and the connection port of the piping is provided in the vicinity of the trunk portion. The connection port can be taken out of the X-ray shielding area 32. The vacuum pipe connection port 17 can be easily provided at a position close to the body portion on the head main body 26, and although not shown, the water supply port and the drain port are provided even when water cooling of the head main body 26 is required. It is possible to provide the head body 26 at a position close to the upper body portion.
[0020]
The irradiation window is cooled by blowing a cooling gas introduced from the outside of the electron beam emission tube onto the irradiation window. Therefore, it is necessary to provide components for cooling the irradiation window inside the X-ray shielding area. In this case, for example, as shown in the embodiment of FIG. 1, when the air-cooled body 20 is fastened to the head main body 26, the connection tube 21 is inserted between the air-cooling body 20 and the airtight body 23 of the connection tube 21. Pressed by the taper part 24 and the parallel part 25 provided in the air cooling body 20, the connection pipe 21, the cooling gas flow path 27 inside the air cooling body 20, the gas blowing port 28, And the continuous air cooling piping path | route which reaches the irradiation window 11 is comprised.
[0021]
By configuring the electron beam emitting tube 10 as described above, the X-ray shielding wall 31 does not require an intermediate connection portion or a labyrinth portion of the pipe, and only a minimum opening / closing portion such as an inlet / outlet port for the irradiated object is provided. It's okay.
[0022]
Further, the procedure for removing the electron beam emission tube 10 from the electron beam irradiation apparatus 30 is simplified as follows, and all operations can be performed outside the X-ray shielding area.
(1) Remove the external cooling gas pipe 16.
(2) Remove the external vacuum pipe 18.
(3) The electron beam emitting tube 10 is pulled out with the casing 19.
[0023]
【The invention's effect】
According to the first aspect of the present invention, since the cooling gas inlet is provided outside the X-ray shielding area of the electron beam irradiation apparatus, the external piping is not exposed to electron beams and X-rays, and resin piping is used. There is no risk of deterioration, and there is no need to route gas piping in the X-ray shielding area of the electron beam irradiation device, so the design and production of intermediate connections and devices can be simplified, and when replacing the electron beam emission tube. In addition, since the connecting pipe can be removed without putting the hand into the X-ray shielding area, there is a special effect that the workability of attaching and detaching the electron beam emitting tube is improved.
[0024]
According to the first aspect of the present invention, since the air-cooled body having the function of fixing the irradiation window is fastened to the head body via the airtight body provided in the connection pipe built in the head body, There is a special effect that the present invention can be applied even when the body and the head main body are separable and the relative position between the air cooling body and the head main body changes due to the elastic deformation of the air cooling body .
[Brief description of the drawings]
FIG. 1 is a schematic front view of an embodiment of the present invention.
2 is a schematic view showing a state where an electron beam emission tube and an external pipe are removed in the embodiment of FIG. 1;
FIG. 3 is a schematic view of a connecting pipe portion embodiment in the invention of claim 2;
FIG. 4 is a schematic view of another connecting pipe portion embodiment in the invention of claim 2;
FIG. 5 is a schematic view of an electron beam irradiation apparatus in the prior art.
[Explanation of symbols]
10 Electron Beam Emission Tube 15 Cooling Gas Inlet 20 Air Cooling Body 21 Connection Tube 22 Inner Wall 23 Airtight Body 26 Head Body 32 X-ray Shielding Area 40 Air Cooling Body 41 Connection Tube 42 Inner Wall 43 Airtight Body

Claims (1)

An electron beam emission tube comprising a head portion having an irradiation window made of a material that transmits an electron beam, and a body portion that is made of an electrically insulating material with an electron generation portion disposed at a position facing the head portion And an X-ray shielding area that has an opening for attaching the electron beam emission tube, surrounds the area where the electron beam irradiation is performed, and is separated by an X-ray shielding wall that shields the X-rays generated during the electron beam irradiation. In an electron beam irradiation apparatus comprising:
The head portion is
An air cooling body that also serves as a pressing body that incorporates an air cooling path through which a cooling gas for cooling the irradiation window flows, and presses and fixes the irradiation window;
The air cooling body is fastened to the irradiation window side end portion, and a cooling gas introduction port for cooling the irradiation window and a vacuum pipe connection port for keeping the inside of the electron beam emission tube at a high vacuum are provided on the side surface. A head body incorporating a continuous air cooling path from the cooling gas inlet;
Consisting of
By fastening the air cooling body to the head body,
At the same time that the irradiation window is hermetically fixed to the head part,
A continuous air cooling path from the cooling gas inlet to the irradiation window via a connecting pipe having a rigid inner wall and an airtight body provided on the outer periphery of the inner wall is configured inside the head part,
The electron beam irradiation apparatus according to claim 1 , wherein the vacuum pipe connection port and the cooling gas introduction port are provided at a position located outside the X-ray shielding area .

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