JP2000214299A - Electron beam irradiator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to finish repairs in a short down time even if an electron accelerator is out of order by holding a means for accelerating electrons where an accelerating tube, a scanning tube and a cooling wind header constitute a set in a moving base so that they can be drawn out. SOLUTION: A shield plate 26 is fixed onto a moving base 30, and a connection route 23 is fixed on the plate 26. Then, an accelerating tube 22 is fixed on the moving base 30 by a stay 21 outside a shield chamber 10, a scanning tube 24 is fixed on the shield plate 26 by a stay 25 inside the shield chamber 10 and a cooling wind header 28 is located in an opening of the scanning tube 24. Moreover, a cooling wind duct 35 is buried inside the moving base 30, is exposed in a buried part 38 on the side where ventilated air exhausts and is connected to the cooling wind header 28. A cooling blower 34 is also fixed behind the accelerating tube 22 on the moving base 30. In this way, only the scanning tube 24 is included in the shield chamber 10, so that the chamber 10 can be made compact, the construction time and materials can be reduced and an electronic accelerator 20 can also be brought out quickly.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electron beam irradiating apparatus which uses an electron beam for industrial purposes and gives a desired change to the properties of an irradiation object.

[0002]

2. Description of the Related Art Generally, an electron beam of the above-mentioned electron beam irradiation apparatus is irradiated on an irradiation object by the following mechanism. That is, a thermoelectron is generated by a filament arranged in an electron accelerator held in a vacuum, and the thermoelectron is accelerated inside the electron accelerator to form an electron beam.
The electron beam is transmitted through a metal window foil attached to the electron accelerator at an opening arranged opposite to the filament of the electron accelerator so as to cut off the vacuum inside the electron accelerator from the outside, and is irradiated onto an irradiation target. The accelerated electrons lose some energy when they pass through the metal window foil, and are converted into heat, so that the metal window foil is blown by the cooling wind by the cooling wind header and the strength does not deteriorate. Is cooled to the temperature of As the metal window foil, a foil of several to several tens of μm usually made of titanium or a titanium alloy is often used, and the temperature of the cooling state in that case is 200 to 400 ° C.

[0003] There is known an electron beam exhaust gas treatment apparatus for irradiating an exhaust gas such as a boiler combustion exhaust gas containing a sulfur oxide and / or a nitrogen oxide with an electron beam to remove such pollutants. In such a device, it is necessary to irradiate the electron beam over a wide area and uniformly, and the thermoelectrons are scanned after being accelerated.
The accelerator portion serves as an acceleration tube, and a scanning tube is provided at an opening thereof, and a metal window foil is disposed at the opening of the scanning tube.
A connection path may be used to connect the accelerator and the scanning tube.

FIG. 3 is an enlarged cross-sectional view of an electron beam irradiation device and an irradiation container of a conventional electron beam exhaust gas treatment device. The electron accelerator 40 includes an accelerating tube 42 for accelerating thermoelectrons generated by the filament inside the electron accelerator 40 to form an electron beam;
A scanning tube 44 that scans the electron beam from the accelerating tube 42 via the connection path 43 is provided. The scanning tube 44 transmits a metal window foil attached to an opening of the scanning tube 44 to the irradiation target in the irradiation container 16. The electron beam is scanned and irradiated. To remove the heat generated when the electron beam passes through the metal window foil attached to the scanning tube 44, the outer surface of the metal window foil and the irradiation container 16 are removed.
A cooling air header 48 for cooling the metal window foil is disposed between the cooling air header 48 and the cooling air header 48.

Here, when an irradiation target is irradiated with an electron beam, secondary X-rays are generated accordingly. For this reason, the electron accelerator 40 is arranged in the shielding room 14 whose wall surface is made of concrete (two units in FIG. 3), and the irradiation container 1
Shielding room 1 behind electron accelerator 40 when 6 is the front
An openable / closable shielding door 46 is arranged on the wall portion 4, and shields the rear secondary X-rays generated by the irradiation of the electron beam with these shielding chambers 14 and the shielding door 46. With this configuration, the X-ray level outside the shielded room 14 can be reduced to a level that is not harmful to the human body. However, since the X-ray level inside the shielded room 14 is very strong, the operator is not irradiated during electron beam irradiation. The worker cannot enter the inside of the shielded room 14.

[0006]

By the way, as in the electron beam irradiation apparatus of the above-mentioned electron beam exhaust gas treatment apparatus, an entrance is provided in the shielding room 14 behind the electron accelerator 40, and when the electron accelerator 40 breaks down, Then, work for repairing from the entrance will be performed. However, in this case, since all of the components of the electron accelerator 40 are disposed inside the shielded room 14, the volume of the shielded room 14 increases. Generally, the shielding room 14 is made of very thick concrete or a material having a high shielding ability, such as lead, in order to shield secondary X-rays generated by electron beam irradiation. For this reason, when the volume of the shielding room R is increased, there is a problem that the construction time, material, space, and the like are both increased or increased. Moreover, such an electron accelerator is a precision instrument, and the one used for exhaust gas treatment equipment is large enough for humans to be able to maintain it, and the weight is considerable, so careful care must be taken when carrying it in and out. There is also a problem.

If the required amount of electron beam irradiation is large, a plurality of electron accelerators 40
Irradiates an electron beam from In such a case, if a part of the plurality of electron accelerators 40 fails, the operator and the worker cannot enter the inside of the shielded room 14 during the electron beam irradiation. All irradiation of the electron beam must be stopped. In the case of repair inside the shielded room 14, the electron beam cannot be irradiated at all during the repair period, so that the entire apparatus must be stopped for a long time. On the other hand, when the failed electron accelerator 40 is carried out of the shielded room 14 and then the partial operation using only the remaining electron accelerator 40 is restarted, and the carried-out electron accelerator 40 is repaired during the partial operation. However, since careful handling is required as described above, it takes a lot of time to carry out and carry in the electron accelerator. As a result, there is a problem that the start of the partial operation is delayed and the operation stop time is lengthened.

Further, cooling air is supplied to the cooling air header 48 via a cooling air duct (not shown) extending from a cooling air blower (not shown) which is usually provided outside the shielding room 14. The cooling air header 48 is fixed to the electron accelerator 40 because the cooling position must be fixed. Therefore, when the electron accelerator 40 is carried out of the shielded room 14 for repair or the like, the cooling air duct must be separated from the cooling air header 48, and there is a problem that the operation stop time becomes long.

[0009] Therefore, an object of the present invention is to solve the above-mentioned problems, and to reduce the size of the shielded room, easily shift to maintenance, and maintain a short operation stop time even if the electron accelerator breaks down. An object of the present invention is to provide an electron beam irradiation device capable of completing repair.

[0010]

Means for Solving the Problems In order to solve the above problems, the present inventors have devised an electron beam irradiation reaction device having the following features. That is, one or more accelerating tubes for accelerating thermoelectrons generated in a substantially vacuum to form an electron beam, a scanning tube connected to the accelerating tubes in a vacuum state and scanning the electron beams from the accelerating tubes,
A metal window foil provided in the electron beam emission opening of the scanning tube and transmitting an electron beam while maintaining a vacuum, and a cooling wind is provided on the metal window foil to the electron beam emission side of each metal window foil. A cooling air header having a blowing slit for blowing,
An irradiation container in which an irradiation gas to be irradiated with an electron beam from a metal window foil flows therein, and at least a metal window foil portion and an irradiation container of the scanning tube are included, and the electron beam irradiation direction of the metal window foil is included. An X-ray shielding room having an opening in a wall at a rear position, a shielding plate which is provided near the scanning tube and which can be separated from the opening of the X-ray shielding room and shields the X-ray, an acceleration tube, a scanning tube, An electron beam irradiating apparatus, comprising: a movable base that holds electron accelerating means as a set of cooling air headers and allows the electron accelerating means to be able to be separated from and connected to the opening of the irradiation container. .

In other words, by using at least the metal window foil portion of the scanning tube as the portion arranged in the shielded room, the number of components housed in the shielded room can be reduced, and the size of the shielded room can be minimized. By holding the electron accelerating means on the movable base, the movable base is pulled out when necessary, so that the entire electron accelerating means can be easily carried out / in from the shielded room. Maintenance can be easily shifted to, and even if the electron accelerator breaks down, repair can be completed in a short operation stop time.

The electron beam irradiation reaction apparatus of the present invention can have the following configuration. The electron beam irradiation apparatus according to claim 1, further comprising a cooling air duct embedded inside the movable base so as to straddle the shielding plate and supplying cooling air to the cooling air header. The electron beam irradiation apparatus according to any one of claims 1 to 3, wherein the shielding plate is disposed between the acceleration tube and the scanning tube, and has a through hole through which an electron beam flow path passes. The electron beam irradiation apparatus according to claim 1, wherein the acceleration tube is made of a material that shields rear secondary X-rays that pass through a through hole of the shielding plate. The opening of the shielding room has a shielding door that can be closed instead of the shielding plate after the shielding plate is removed by moving the movable base, Electron beam irradiation device. The electron beam irradiation apparatus according to claim 1, wherein the movable base includes a cooling blower connected to the cooling air duct at a position behind the shielding plate. A plurality of the electron accelerating means which are held by the movable base and include a set of an accelerating tube, a scanning tube, and a cooling wind header are provided, and each of the electron accelerating means is disposed in a plurality of openings provided in the shielding chamber. An electron beam irradiation apparatus according to any one of the above.

In the above configuration, the cooling air duct is buried in the movable base so as to be covered with the shielding material and then bent, so that X-rays leaking through the pipe can be attenuated. . In the above configuration, the acceleration tube portion is disposed outside the shielded room, and it is not necessary to move even the movable base when the acceleration tube portion fails. At this time, as described above, in order to shield the secondary X-rays behind from the through hole of the shielding plate, it is preferable that the acceleration tube is made of an X-ray shielding material. In the above configuration, the X-rays from the opening of the shielded room are shielded by the shielding door that closes the opening of the shielded room during the partial operation using only the remaining electron accelerators after the failed electron accelerator is carried out. In the above configuration, the complete set of the electron acceleration means and the cooling means can be mounted on the movable base in a completed form, and the arrangement of devices other than the movable base can be simplified, and the repair work can be made more efficient. In the above configuration, when a plurality of electron accelerating means are provided in the shielded room, each electron accelerating means can be separately moved on the movable base. Therefore, only the electron accelerating means which has failed due to the movement of the movable base. The removal of the electron accelerator from the shielded room to the outside is instantaneously completed, and then the partial operation using only the remaining electron accelerator is resumed, and the removed electron accelerator can be repaired during the partial operation Becomes

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an electron beam irradiation reaction apparatus according to the present invention will be described with reference to the drawings. FIG. 1 is a partial cross-sectional view when an electron beam irradiation apparatus according to an embodiment of the present invention is employed in an electron beam exhaust gas treatment apparatus. In the electron beam irradiation apparatus shown in FIG. 1, an accelerating tube 2 for accelerating thermoelectrons generated in a filament inside the electron beam to form an electron beam.
2 and a scanning tube 24 that scans the electron beam from the accelerating tube 22 via the connection path 23, and transmits the metal window foil attached to the opening of the scanning tube 24 to irradiate the irradiation inside the irradiation container 12. An object is scanned and irradiated with an electron beam. A cooling air header 28 for cooling the metal window foil is disposed between the outer surface of the metal window foil and the irradiation container 12. The acceleration tube 22, the scanning tube 24, and the cooling air header 28 constitute an electron accelerator 20 as electron acceleration means.

Here, similarly to the prior art, when an irradiation target is irradiated with an electron beam, secondary X-rays are generated accordingly. In order to prevent the divergence of the secondary X-rays, in the electron accelerator 20, a portion from the scanning tube 24 to the cooling air header 28 is included in the shielding room 10 whose wall surface is made of concrete. Further, in this shielded room 10, since the wall at the position of the connection path 23 between the acceleration tube 22 and the scanning tube 24 becomes an opening, a through hole is provided for passing the connection path 23 which is a flow path of the electron beam. Arranged so as to be closed by the shielding plate 26 to prevent leakage of the secondary X-ray from the opening of the shielding room 10. Furthermore, by forming the outer periphery of the accelerating tube 22 with lead having a high voltage insulation distance, it is possible to prevent the secondary X-rays passing through the through-hole through the connection path 23 in the shielding plate 26 from wetting. . Thus, the X-ray level outside the shielded room 10 can be suppressed to a level that does not affect the human body. The electron accelerator 20 including the acceleration tube 22, the scanning tube 24, and the cooling air header 28, and the shielding plate 26 are fixedly arranged on a movable base 30 made of concrete. In the present embodiment, two sets of the electron accelerators 20 are arranged in the shielded room 10 and irradiate an irradiation target in the irradiation container 12 while scanning the electron beam.

FIG. 2 is an enlarged view of the electron accelerator portion of the XX ray shown in FIG. As shown in the figure, the shielding plate 26 is fixed on the movable base 30, and the connection path 23, which is a through hole through which the electron beam flow path passes, is fixed to the shielding plate 26. With the connection path 23 as the center, the accelerating tube 22 is fixed to the movable base 30 by the stay 21 outside the shielding chamber 10. The scanning tube 24 is fixed to a shielding plate 26 by a stay 25 inside the shielding room 10. Further, a cooling air header 28 is arranged at the opening of the scanning tube 24.

Further, a cooling air duct 35 for supplying cooling air to the cooling air header 28 is embedded inside the movable base 30 so as to straddle the shielding plate 26. A cooling blower 34 connected to the cooling air duct 35 exposed at the air supply side embedded portion 36 is fixed at a position behind the acceleration tube 22 on the movable base 30. In addition, the cooling air duct 35 is exposed at the buried portion 38 on the ventilation and discharge side, and is connected to the cooling air header 28. With such a configuration, the cooling air supplied from the cooling air blower 34 to the cooling air header 28 via the cooling air duct 35 is blown onto the metal window foil from the slit attached to the cooling air header 28. It should be noted that the air outlet side buried portion 38 which is a portion where the cooling air duct 35 is buried in the movable base 30
Has a protruding shape from the movable base 30, and by bending the cooling air duct 35 in this protruding shape, the leakage of the secondary X-ray that proceeds straight is prevented.

The movable base 30 holding the components of the electron accelerator 20 in the above configuration is placed on a rail 32,
It can move back and forth in the direction of the irradiation container 12 in the shielding room 10. The movement form in FIG. 1 is movement on a rail,
Movable base 30 made of concrete and having some weight
Any structure can be used as long as it can be moved out of the shielded room 10. For example, a rubber tire can be used.

Further, after the movable base 30 is moved, a configuration is possible in which an opening and closing shield door is disposed at the opening of the shielding chamber 10. Therefore, the moving out of the movable base 30 causes the failed electron accelerator alone to be immediately carried out of the shielded room 10 to the outside. Thereafter, the opening of the shielded room 10 is closed by the shielded door, and the secondary X-ray is blocked. It is configured to be able to shield. After such a state, the partial operation using only the remaining electron accelerators is resumed, and the carried-out electron accelerator is repaired during the partial operation.

As described above, since only the scanning tube 24 of the electron accelerator 20 is included in the shielded room 10, the shielded room 10 can be made compact, and the construction time, material, installation space, and the like can be reduced. It can be reduced or reduced. Furthermore, since the cooling air duct 35 is buried inside the movable base 30 so as to straddle the shielding plate 26, it is not necessary to remove the cooling air duct 35 from the cooling air header 28 when the movable base 30 moves. 20 can be simplified. Furthermore, since the cooling air blower 34 is also installed on the movable base 30, the cooling air duct 35 does not need to be separated from the cooling air blower 34,
The removal of the electron accelerator 20 from the shield room 10 can be performed more quickly.

Here, in the cooling blower 34, a gas other than the atmosphere can be used. In addition, movable base
Even if the cooling blower is not fixed to the cooling air supply means, the elastic duct is extended from the cooling gas supply means fixed outside the shielded room 10 and connected to the cooling air duct 35 to move the movable base. You can also respond. In such a case, an exhaust duct having the same configuration as the cooling air duct 35 can be provided on the movable base to purify the exhaust gas after cooling, and then reuse it as cooling air. Also, in FIG.
2 is disposed outside the shielded room 10, but is disposed inside the shielded room 10, and is disposed on the movable base 30.
It is possible to adopt a configuration in which only the cooling blower is provided as an element disposed outside the device. In this case, the shielding plate is disposed between the acceleration tube and the cooling blower, and there is no need to provide a through hole for a connection path, and it is not necessary to use lead on the outer wall of the acceleration tube.

[0022]

As described above, according to the present invention,
Since the electron accelerator and the means for cooling the metal window foil are mounted on the movable base, the movable base is moved to carry only the failed electron accelerator from the shielded room to the outside. Is completed quickly, and the electron accelerator can be repaired. Thereafter, when a plurality of electron accelerators are used, the partial operation using only the remaining electron accelerators is restarted, and the carried-out electron accelerator can be repaired during the partial operation. The electron accelerator and the cooling means can be mounted on the movable base in a complete form, so that the equipment other than the movable base can be simplified, and the repair work can be made more efficient. Further, the acceleration tube portion is disposed outside the shielded room, and the movable base is required in the event of a failure of the acceleration tube portion.
There is no need to move even. At this time, by making the acceleration tube an X-ray shielding material, it is possible to shield the rear secondary X-rays from the through holes of the shielding plate. In addition, after taking out the failed electron accelerator by the shielding door that closes the opening of the shielding room,
At the time of partial operation using only the remaining electron accelerators, X-rays from the opening of the shielding room are shielded.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view when an electron beam irradiation apparatus according to an embodiment of the present invention is employed in an electron beam exhaust gas treatment apparatus.

FIG. 2 is an enlarged view of an electron accelerator portion of the XX line shown in FIG.

FIG. 3 is an enlarged cross-sectional view of an electron beam irradiation device and an irradiation container of a conventional electron beam exhaust gas treatment device.

[Explanation of symbols]

 10, 14 shielding room 12, 16 irradiation container 20, 40 electron accelerator 22 accelerating tube 23 connection path 24 scanning tube 26 shielding plate 28 cooling air header 30 movable base 32 rail 34 cooling blower 35 cooling air duct

Claims (5)

[Claims] At least one accelerating tube for accelerating thermoelectrons generated in a substantially vacuum to generate an electron beam is connected to the accelerating tube in a vacuum state, and scanning for scanning an electron beam from the accelerating tube is performed. A tube, a metal window foil provided in the electron beam emission opening of the scanning tube to transmit an electron beam while maintaining a vacuum, and a metal window foil provided to the electron beam emission side of each metal window foil. A cooling air header having a blowing slit for blowing cooling air, an irradiation container through which an irradiation gas to be irradiated with an electron beam from a metal window foil flows, and at least a metal window foil portion and an irradiation container of a scanning tube. An X-ray shielding room that includes an opening in a wall behind the metal window foil with respect to the direction of electron beam irradiation, and an X-ray that is provided near the scanning tube and is detachable from the opening of the X-ray shielding room. Shielding plate for shielding, acceleration tube, scanning tube, cooling Holding the electron accelerating means and a pair of headers, movable base allows detaching the opening portion of the irradiation container electron accelerating means - electron beam irradiation apparatus, comprising scan and, a. 2. An electron beam irradiation apparatus, comprising a cooling air duct buried inside the movable base so as to straddle a shielding plate and supplying cooling air to a cooling air header. 3. The electron beam irradiation according to claim 1, wherein the shielding plate is disposed between the acceleration tube and the scanning tube, and has a through hole through which an electron beam flow path passes. apparatus. 4. The electron beam irradiation apparatus according to claim 3, wherein the acceleration tube is made of a material that shields a rear secondary X-ray that passes through a through hole of the shielding plate. 5. The opening of the shielding room, after the shielding plate is removed by moving the movable base,
The electron beam irradiation apparatus according to any one of claims 1 to 4, further comprising a shield door that can be closed instead of the shield plate.