JPH11118999A - Bi-directional irradiation electron gun and gas-treating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the pressure loss of electron guns, the number the electron guns, and costs by providing an electron beam transmission window and an anode at a plurality of positions of the outer-enclosure part of a cylindrical vacuum container and arranging a cathode unit being provided so that it is paired with the anode on the center line of the container. SOLUTION: Electron beam transmission windows 2 and 3 are provided at the outer-enclosure part of a vacuum container 1 while being separated and a pair of electrodes 4 and 5 are provided inside in parallel. A cathode unit 8 consisting of two cathodes 6 and 7 being provided so that they can be paired with the anodes 4 and 5 is arranged at nearly the center in the container 1. Electrons beams 13 are emitted from the recessed part of the unit 8, pass between two parallel anodes 4 and 5, and are discharged into a gas through the transmission windows 2 and 3. The beams 13 are discharged in two directions symmetrically with a symmetrical surface 14. The beams 13 are emitted in two opposite directions against a gas flow from one electron gun, thus increasing the interval of the electron guns and reducing a pressure loss, reducing the number of the electron guns, and reducing costs.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bidirectional irradiation electron gun and a gas processing apparatus, and more particularly to an electron gun applied to an electron beam reaction vessel of a gas processing apparatus, a film processing apparatus, an ink drying and solidifying apparatus, and this electron gun. The present invention relates to a gas processing apparatus using the same.

[0002]

2. Description of the Related Art In a conventional gas processing apparatus using an electron beam, an electron gun is placed outside a gas tube and an electron beam accelerated to a high voltage and high energy is used to irradiate all the gas in the gas tube with the electron beam. Was. At this time, the electron gun used a point electron source.

FIG. 7 shows a conventional point electron source high voltage electron gun. Reference number 21 in the figure is a vacuum container. This vacuum vessel 21
An electron beam transmission window 23 which forms a part of the vacuum vessel 21 is provided on the bottom side (on the gas pipe 22 side). In the vacuum vessel 21, a heater 24, an electron-emitting material 25, a donut-shaped anode 26, and a deflecting magnet 27 are arranged in this order from the upper side of the vessel 21. The electron emission material 25 is heated by the heater 24. Reference numeral 28 in the drawing denotes an electron beam emitted from the electron-emitting material 25.

In the case of the point electron source high voltage electron gun shown in FIG. 7, many X-rays were generated. In order to suppress the generation of X-rays, it is necessary to lower the accelerating voltage. However, in this case, the range of the electron beam in the atmosphere becomes short, so that it cannot be applied to a large-diameter gas pipe. In order to solve this, a long linear cathode type electron gun which can be incorporated into a gas tube is suitable. Conventionally, there was no such an electron gun.

[0005]

In order to suppress the generation of X-rays, it is necessary to lower the accelerating voltage of the electron beam and irradiate an object in the atmosphere such as a gas at about 300 KV. At this time, since the range is about 70 cm, the interval between the linear electron guns is about 70 cm at the maximum, which is narrow, and the number of linear electron guns is large.

The present invention has been made in view of such circumstances, and provides an electron beam transmission window and an anode at two locations on the outer periphery of a cylindrical vacuum vessel, and pairs the anode with the anode on the center line of the vacuum vessel. By arranging a cathode unit having two cathodes provided so that
The direction of gas flow from one electron gun
A two-way irradiation electron gun that emits an electron beam in the direction, reduces the pressure loss by widening the interval between the electron guns incorporated in the gas pipe, halves the number of electron guns, and has a low cost and small occupation area. The purpose is to provide.

According to the present invention, the bidirectional irradiation electron gun is arranged so as to irradiate the electron beam in a direction crossing the flow of the gas to be treated, and the gas treatment is performed. An object of the present invention is to provide a gas processing device applicable to a large-diameter gas pipe.

[0008]

According to a first aspect of the present invention, there is provided a cylindrical vacuum vessel, an electron beam transmitting window and an anode provided at two positions on the outer periphery of the vacuum vessel, and a center line of the vacuum vessel. And a cathode unit having two cathodes provided so as to be paired with the anode.

In the first invention, it is preferable that the cathode unit has an electron-emitting material and a focusing electrode having an angle of 67.5 ° with respect to a direction of an electron beam generated from the electron-emitting material.

A second invention of the present application is a gas processing apparatus characterized in that a gas treatment is performed by disposing a bidirectional irradiation electron gun so as to irradiate an electron beam in a direction crossing the flow of a gas to be treated.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A bidirectional irradiation electron gun according to one embodiment of the present invention will be described below with reference to FIG. Reference numeral 1 in the figure denotes a cylindrical vacuum vessel. This vacuum vessel 1
The inside is kept at a vacuum pressure of the order of 10 ⁻⁷ Torr or less.
Electron beam transmission windows 2 and 3 forming a part of the vacuum vessel 1 are provided separately from each other at an outer portion of the vacuum vessel 1. Inside the electron beam transmission windows 2 and 3, a pair of rod-shaped anodes 4 and 5 are provided in parallel with each other. A cathode unit 8 including two cathodes 6 and 7 provided so as to be paired with the anodes 4 and 5 is disposed at a substantially central portion in the vacuum vessel 1. Here, the cathode unit 8 has a substantially Dharma-shaped cross-sectional shape.

The cathode unit 8 has a sectional shape as shown in FIG. That is, one cathode 6 is provided with focusing electrodes 6 ₁ and 6 ₂ , respectively, and the other cathode 7 is provided with focusing electrodes 7 ₁ and 7 ₂ , respectively. An electron-emitting material (cathode material) 9 is disposed in a recessed portion (closer to the inside) of the cathode unit 8 so as to be electrically insulated from the outer periphery 10 of the cathode unit 8. Here, when a cathode material impregnated with, for example, BaO powder or the like is used as the electron-emitting material 9, a predetermined amount of current can be obtained by heating to 1000 to 1100 ° C. Inside the electron emitting material 9, heaters 11 are arranged independently in two directions to heat the material 9. The electron emission material 9 is heated mainly by radiation from the heater 11. The electron emitting material 9 is provided in a gap of about 1 mm width provided on the outer periphery 10 of the cathode.
An electron beam 13 is emitted from 12. Then, by controlling the potentials of the electron emitting material 9 and the cathode outer periphery 10, the electron beam current from the electron emitting material 9 can be adjusted.

In the bidirectional irradiation electron gun having such a configuration, the electron beam 13
After passing between the two parallel anodes 4 and 5, is emitted into the gas through the electron beam transmitting windows 2 and 3.
The electron beam 13 is emitted in two directions symmetrically with respect to the plane of symmetry 14.
Also, the electron beam 13 is not in the opposite direction but about 67.5 ° with respect to the downstream direction of the gas flow in the vacuum vessel 1.
Each is open at an angle of (θ).

This is because, as shown in FIG.
_When the angle of ₁ , 6 ₂ (or 7 ₁ , 7 ₂ ) becomes 67.5 ° with respect to the electron beam 13, the electron beam 13 emitted from the electron-emitting material 9 travels in parallel by the action of the electric field. It was used. That is, when the focusing electrode 7 ₂ of one of the focusing electrodes 7 ₁ Tomo one electron beam source is made parallel, the electron beam 13 of each will be 67.5 ° with respect to the gas downstream direction. By doing so, the electron beam transmission windows 2 and 3 are less likely to receive pressure due to the flow of gas, and the distance between the electron guns is kept wide and the balance is good.

FIG. 3 is a characteristic diagram showing the relationship between the radius of the cathode protrusion of the cathode unit and the maximum electric field intensity on the surface. The size of the cathode unit 8, particularly the radius of curvature of the curved portion, is
Or 300 KV applied between the vacuum vessel 1 and the cathode unit 8
It is necessary to decide so as not to cause dielectric breakdown at the voltage. Empirically, if the electric field strength on the surface is 100 KV / cm or less, dielectric breakdown is unlikely. Therefore, the radius of curvature is plotted on the horizontal axis, and the maximum electric field strength on all surfaces is calculated on the vertical axis, and the maximum value is obtained. For example, when the inner diameter of the vacuum vessel 1 is φ250 mm,
The radius of curvature r of the cathode unit 8 is about 25 to 35 mm and 10
The condition of 0 KV / cm or less was satisfied.

FIG. 4 shows an equipotential surface distribution of the upper half of the cross section of the cathode unit, which is one configuration of the electron gun, when the radius of curvature r is 24 cm. When the cathode unit 8 is linear and long,
Since it is difficult to support the cylindrical surface of the vacuum vessel 1 in terms of insulation, as shown in FIG. 5, insulators 14 are provided on the upper and lower sides, and the insulators 14 are hung therefrom and received below. The side of the insulator 14 away from the vacuum vessel 1 is at a negative high potential of 300 KV and is in the atmosphere, so that corona ring is used to prevent discharge in the atmosphere.
Surrounded by 15. Then, heating of the heater, control of the potential between the cathode unit 8 and the outer periphery of the cathode 10 and supply of a high voltage are performed from the corona ring 15 with a high-voltage cable.

FIG. 6 shows a wiring diagram of the bidirectional irradiation electron gun shown in FIG. In FIG. 6, a heater 11 is connected to a heater power supply 61.
There are connected, to the electron-emitting material 9 is connected controlled power supply 62 has a high-voltage power supply 63 is connected to a further focusing electrode 7 ₁ and the anode 5. The heater power required 2-3 KW per 1 m of electron gun length.

However, the bidirectional irradiation electron gun according to the above embodiment is configured to emit the electron beams 13 in two directions opposite to each other with respect to the gas flow from one electron gun. The distance between the electron guns incorporated in the gas pipe is increased, and the pressure loss is reduced. Also, the number of electron guns is halved. Therefore, as compared with the conventional point electron source high voltage electron gun, the cost can be reduced and the occupied area can be reduced.

Further, the conventional point electron source is constructed by arranging the bidirectional irradiation electron gun having such a structure so as to irradiate the electron beam 13 in a direction traversing the flow of the gas to be processed. Compared to a gas processing apparatus using a high-voltage electron gun, it is possible to realize a gas processing apparatus that suppresses the amount of X-ray generation and is applicable to a large-diameter gas pipe.

[0020]

As described above in detail, according to the present invention, an electron beam transmitting window and an anode are provided at two locations on the outer periphery of a cylindrical vacuum vessel, and the anode and the anode are paired with each other on the center line of the vacuum vessel. A configuration in which a cathode unit having two cathodes provided so as to be arranged is arranged so that an electron beam is emitted from a single electron gun in two directions opposite to each other with respect to a gas flow. In addition to increasing the distance between the electron guns built into the tube to reduce pressure loss,
It is possible to provide a low cost, small occupying area bidirectional irradiation electron gun by halving the number of electron guns.

Further, according to the present invention, the bidirectional irradiation electron gun is arranged so as to irradiate the electron beam in a direction crossing the flow of the gas to be treated, and the gas treatment is performed. It is possible to provide a gas processing apparatus that can be applied to a large-diameter gas pipe while suppressing the occurrence of gas.

[Brief description of the drawings]

FIG. 1 is a schematic overall view of a bidirectional irradiation electron gun according to an embodiment of the present invention.

FIG. 2 is a sectional view of a cathode unit which is one configuration of the electron gun of FIG. 1;

FIG. 3 is a characteristic diagram showing a relationship between a radius of a cathode protrusion and a maximum surface electric field intensity of the cathode unit shown in FIG. 2;

FIG. 4 is an equipotential surface distribution of the upper half of the cross section of the cathode unit shown in FIG. 2 when the radius of curvature r is 24 cm.

FIG. 5 is an external view in which the electron gun shown in FIG. 1 is assembled.

FIG. 6 is a wiring diagram of the electron gun shown in FIG.

FIG. 7 is an external view of a conventional point electron source high voltage electron gun.

[Description of Signs] 1 ... Vacuum container, 2, 3 ... Electron beam transmission window, 4,5 ... Anode, 6,7 ... Cathode, 8 ... Cathode unit, 9 ... Electron emission material, 10 ... Cathode outer periphery, 11 ... Heater , 12 ... gap, 13 ... electron beam, 14 ... symmetry plane.

Claims (3)

[Claims] 1. A vacuum vessel having a cylindrical shape, an electron beam transmitting window and an anode provided at two locations on an outer portion of the vacuum vessel, and arranged on a center line of the vacuum vessel so as to be paired with the anode. And a cathode unit having two cathodes provided for the two-way irradiation electron gun. 2. The cathode unit, comprising: an electron emission material;
2. The bidirectional irradiation electron gun according to claim 1, further comprising a focusing electrode having an angle of 67.5 [deg.] With respect to a direction of an electron beam generated from the electron emitting material. 3. The gas processing according to claim 1, wherein a gas is processed by disposing a bidirectional irradiation electron gun so as to irradiate the electron beam in a direction crossing the flow of the gas to be processed. apparatus.