JP2003290322A - Radiation irradiation apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To bring out the original function of a filter by effectively utilizing the filter and to prevent the filter from becoming a bacteria source. <P>SOLUTION: The filter 12 for adsorbing microbe attached particles 13' and an electron beam irradiator 3 are mounted in a duct 1. The electron beam irradiator 3 has an electron beam taking-out window 7 for taking out electron beams 5. The electron beam taking-out window 7 has a release surface 8 for releasing in-duct electron beam 9 into the duct 1 by touching a fluid 2 inside the duct 1. The survival rate of microbes is extremely reduced by irradiating the in-duct electron beams 9 because cells of microbes are destroyed. The probability of propagation of microbes in the population of the threshold or smaller in the filter is extremely low. The survival rate of microbes having passed the filter is more extremely reduced after the irradiation of the in-duct electron beam 9, so that the attack rate caused by suction of microbes in the population of the threshold or smaller is extremely low. The relation between the range distance of electron beams and the width of the duct is considered, so that destruction of microbes is ensured. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radiation irradiation apparatus, and more particularly to a radiation irradiation apparatus for suppressing the growth of microscopic life in a fluid such as an air duct of a medical facility or a food and drink manufacturing facility by sterilizing it. Regarding

[0002]

2. Description of the Related Art In medical facilities such as hospitals, food and beverage manufacturing facilities such as drinking water makers, and air conditioning equipment, air ducts for air circulation such as exhaust fans and blowers are three-dimensional. It is located in. The dust floating in the air is forcibly scattered in every corner by the air flow created by the blower and exhaust fan. For the collection of such dust,
A filter is provided in the air duct. The damp dust has micro organisms such as bacteria, molds and viruses that have not lost their ability to reproduce. The dust attached to living organisms collected by the filter dries, the growth of the attached living organisms is effectively suppressed, and an accident such as nosocomial infection is unlikely to occur. In this way the filter is working effectively.

In a high humidity environment where the humidity is extremely high and the drying of dust does not proceed, it is known that bacteria having a density above a threshold value captured by a filter along with an appropriate amount of nutrients and an appropriate amount of water rapidly propagate. ing. Collisional capture of the filter constituent fibrous material or the filter constituent porous material, or
Dust due to dust capture, which is a diffuse trap in the filter,
Due to the increase in the air pressure inside the duct due to the increase in the trapped amount, the air often passes through the filter, is separated from the filter, and is diffused again into the room. Such breeding and dissipation is one of the causes of nosocomial infections.

A filter cannot be expected to have a long-term capturing performance. Increasing filter replacement frequency increases maintenance costs. There is known a technique of irradiating bacteria in a gas flow toward a filter with ultraviolet rays. Typical examples of bacteria floating in the air are molds. UV rays
Low killing effect against molds. It is possible to use an electron beam instead of ultraviolet rays. A technique of irradiating a fluid flowing in a pipe with an electron beam to perform a physical / chemical treatment on the fluid is known as shown in FIG. This known electron beam irradiation technique is known as a treatment technique for performing desulfurization treatment or denitration treatment on a fluid such as gas or powder or the fluid 101. It is considered that there was a blind spot in the use of such electron beams. FIG. 17 shows the relationship between the arrival distance (depth or depth equivalent amount) of the electron beam in the fluid to be processed and the absorbed dose at the depth position. The absorbed dose is higher in a deep region where the electron beam has advanced more than in a shallow region where the electron beam starts to contact the fluid, and conversely less in a deep region where the electron beam has advanced further.

The distribution of such absorbed dose is a well-known physical fact, but a problem remains when the electron beam irradiation technique is applied to the killing treatment of life-threatening bacteria. As shown in FIG. 17, the initial absorbed dose at the irradiation start point (depth = 0.00) of the electron beam of 300 keV and the depth of 0.
It is the same as the absorbed dose at the position above 06.
The absorbed dose between the points is higher than the initial absorbed dose, but at a depth of 0.
In the region above 06, the dose is smaller than the initial absorbed dose. If the fluid passage cross-section in the duct is wide and the duct diameter in the electron beam traveling direction is large, the absorbed dose is not large enough,
An invalid cross-section area is created which has virtually no killing effect. Increasing the electron beam energy (keV) is as shown in FIG.
As shown in FIG. 7, the absorbed dose is rather reduced, and the amount of non-absorbed electron beams absorbed by the opposing wall of the duct is increased, which causes other obstacles. Reducing the energy of the electron beam can increase the absorbed dose depending on the location, but the effective range is short.

[0006] The filter normally prevents the dissipation of bacteria, but in the case of abnormality, it serves as a hotbed for the growth of bacteria. It is required to effectively utilize the filter and bring out the original function of the filter. It is desirable to use an electron beam for its effective use. When an electron beam is used, it is further required to recognize the effective reach of the electron beam and realize the effective use of the electron beam.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide a radiation irradiating device which effectively utilizes a filter to bring out the original function of the filter and which does not serve as a source of bacteria. Another object of the present invention is to provide a radiation irradiation apparatus capable of recognizing an effective reach of an electron beam used for effective use of a filter and realizing effective use of the electron beam.

[0008]

Means for solving the problem Means for solving the problem are expressed as follows. The technical matters appearing in the expression are accompanied by parentheses (), and numbers, symbols and the like are added. The numbers, symbols and the like are technical matters constituting at least one embodiment or a plurality of examples of the plurality of embodiments or a plurality of examples of the present invention, particularly, the embodiment or the example. It corresponds to the reference numbers, reference symbols, etc. attached to the technical matters expressed in the drawings corresponding to. Such reference numbers and reference symbols clarify correspondences and bridges between the technical matters described in the claims and the technical matters of the embodiments or examples. Such correspondence / bridge does not mean that the technical matters described in the claims are limited to the technical matters of the embodiment or the examples.

The radiation irradiating device according to the present invention constitutes a radiation irradiator (3) provided outside the flow path (1). The radiation irradiator (3) forms a radiation extraction window (7) through which the radiation is extracted, and the radiation extraction window (7) contacts the fluid in the flow channel (1) to cause the radiation (9) in the flow channel (the flow channel (7)). 1)
Has an emitting surface (8) for emitting into. Radiation (9) in the flow path is emitted from the emission surface (8) and emitted.
When the energy is emitted from the emission surface (8), the energy has a range capable of surely flying to the opposite surface of the flow path (1) opposed to.

As described above, the physical properties of the substance in the flow channel (1) are designed by intentionally giving the range of radiation flying from the emitting surface to the facing surface without completely losing energy. Can be changed on the cross section of the flow path, which improves and ensures the efficiency and yield of the substance treatment. X-rays as radiation that can skillfully utilize physical effects in which flight distance in the middle of range and energy conservation rate are not linear
In addition to γ-rays and α-rays, electron beams are the most suitable examples because they are charged particles and can be easily generated. However,
The invention is particularly effective when charged particles, especially electron beams, are used as radiation.

The radiation irradiating apparatus according to the present invention further comprises a filtering device provided in the channel (2) for removing a substance whose physical properties are changed by the radiation (9) in the channel from the channel. Examples of the filtering device include a woven fabric and a filter formed of a porous plate, as well as a device that performs physical property conversion such as distillation, catalyst reforming device, high temperature, and freezing. In particular, the irradiation of the radiation (9) in the flow channel destroys the cells of the microorganisms and extremely reduces the survival rate thereof. The probability that the number of microorganisms below the threshold will grow on the filter is extremely low. The survival rate after irradiation of the radiation (9) in the flow path of the microorganisms that have passed through the filter is extremely low, and the disease incidence due to the inhalation of the microorganisms having the number of individuals below the threshold value is extremely low.

The radiation (9) in the flow channel is emitted from the emission surface (8) and reliably travels to the facing surface of the flow channel (1) facing the emission surface (8). Since the range of the radiation (9) in the channel is longer than the width in the channel in the direction of the radiation (9) in the channel, the radiation (9) in the channel should disappear in the middle of the channel. There is no.

The emission energy of the in-channel radiation (9) emitted from the emission surface (8) is larger than the first set energy, and the arrival energy of the in-channel radiation (9) reaching the facing surface is It is larger than the second set energy. Second
The set energy is not zero. The fact that the first set energy is substantially equal to the second set energy means that the energy of radiation is effectively used. By setting the energy at both ends, the range can be made sufficiently long. The approximately equal energy at the endpoints maximizes energy efficiency.

The radiation (9) in the flow channel has an emission line vector at the emission surface (8), and the emission line vector intersects the flow channel formed in the flow channel (1) at an angle. . Radiation in a channel with a range set to be longer than the channel width (9)
Is reflected by the facing surface, is absorbed by the fluid (2), and has a small transmission dose that is wastefully transmitted through the flow path (1). The amount of absorption of radiation having a range set sufficiently long increases. The oblique incidence of the in-channel radiation (9) on the opposite surface further increases the absorbed dose.

The facing portion forming the facing surface is a reflective layer (1
It is preferable to have 8). It is preferable that the atomic number of the atoms of the substance forming the reflective layer (18) is larger than the atomic number of the atoms of the substance forming the flow path (1), since the reflectance can be increased and the absorbed dose can be increased. . It is preferable that the radiation (9) in the flow channel has an emission line vector at the emission surface (8), and the emission line vector obliquely intersects the facing surface which is the inner surface of the reflective layer (18).

A baffle plate (23) for obstructing the flow is added in the flow path portion of the flow path (1) in which the radiation irradiator (3) is arranged. The radiation in the flow path (9) has an emission line vector at the emission surface (8), and the direction of the emission line vector is the flow path portion (2 ′) formed by the baffle plate (23).
Is substantially parallel to the flow path direction of. Such a flow channel configuration is
Increase absorbed dose.

A magnet 22 is further added to the flow path part of the flow path (1) in which the radiation irradiator (3) is arranged. A part of the radiation (9) in the flow channel is subjected to Lorentz force and strays irregularly, so that more of it is absorbed.

The filter is arranged downstream or upstream of the radiation extraction window (7), and its upstream and downstream arrangements have biologically the same bactericidal effect. Two filters can be used. One is arranged downstream of the radiation extraction window (7), and the other one is arranged upstream of the radiation extraction window (7). Not only is the use of two more reliable, but also the weakening of each individual capture force can reduce the overall cost.

It is preferable to cool the facing surface, and the facing surface is positively cooled.

The radiation irradiating apparatus according to the present invention has the same effect as the above-mentioned structure as shown in FIG. 14 by the following structure: the duct (1) and the microorganism-adhered particles interposed in the duct (1). Filter for adsorbing particles such as (1
2) and an electron beam irradiator (3) arranged outside the duct (1), and the electron beam irradiator (3) has an electron beam extraction window (7) for extracting an electron beam, The electron beam extraction window (7) has an emission surface that comes into contact with the fluid in the duct (1) and emits the electron beam (9) in the duct into the duct (1). The duct is formed of a first duct (1) and a second duct (1 ′) that is bent and connected to the first duct (1) on the downstream side of the first duct (1). The flow direction of the line (9) is substantially parallel to the direction of the flow path formed by the second duct (1 ').

The electron beam (9) in the duct is irradiated in the direction of the flow path, and substantially all the electron beams within the range of the electron beam (9) in the duct are absorbed. When the duct has a bent portion, the bent portion is positively utilized.

Lowering the energy of the electron beam can not only reduce the cost of the electron beam irradiator, but also reduce the energy of the bremsstrahlung (example: X-rays) and narrow the range of the generated radiation to reduce the braking. The radiation dose can be reduced, and the radiation countermeasure becomes unnecessary or the countermeasure cost is significantly reduced.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION Corresponding to the drawings, in an embodiment of a radiation irradiation apparatus according to the present invention, an electron beam irradiator and a filter are arranged in a duct. As shown in FIG. 1, the duct 1 has a circular or rectangular cross section, and a fluid 2 is passed through the duct 1 in one direction. Examples of the fluid 2 include circulating air inside the hospital or circulating air inside and outside the hospital. In the following, the fluid is referred to as air 2 or duct air flow 2.
The electron beam irradiator 3 includes a housing 4, an electrode 6 arranged in the housing 4 for emitting an electron beam 5, and an electron beam extraction window 7 arranged in the housing 4.

The electron beam extraction window 7 does not allow the air in the duct 1 to enter the housing 4 at all or only slightly, but allows the electron beam 5 to pass through the duct transparently (balloon). Electrons can be ejected either directly or transparently). An inner side surface of the electron beam extraction window 7 that directly circumscribes the airflow 2 in the duct is defined and set as an electron beam emission surface 8. If the duct 1 has a rectangular cross section, the electron beam emission surface 8 is a flat surface, and if the duct 1 has a circular cross section, the electron beam emission surface 8 is a cylindrical surface. The inner surface of the duct 1 and the electron beam emitting surface 8 are substantially flush with each other (or one curved surface that connects smoothly):
(See FIG. 6), the same surface does not lose the rectifying property of the air flow 2 in the duct, and the inner surface of the duct 1 and the electron beam emitting surface 8 are formed substantially on the same surface. It is emitted from the line emission surface 8 into the duct 1 and passes through the air flow 2 in the duct.
The energy of the electron beam 9 in the duct that penetrates and reaches the opposing wall of the duct 1 is validated. If the electron beam emitting surface 8 projects into the duct 1, the rectifying property is impaired.

The catalyst unit 1 is provided downstream of the electron beam irradiator 3.
1 is disposed so as to be interposed in the duct 1. The air flow 2 in the duct can pass through the catalyst unit 11 transparently. The catalyst unit 11 includes a catalyst that adsorbs and decomposes ozone generated when oxygen is changed by receiving electron beam irradiation. The filter unit 12 is disposed on the downstream side of the catalyst unit 11 so as to be interposed in the duct 1. The filter unit 12 captures dust, minute organic matter, and minute water droplets contained in the air flow 2 in the duct.

The air flow 2 in the duct containing fine water droplets, fine non-organic matter, dust 13 such as fine organic matter, oxygen-based molecules / atoms 14, nitrogen and other non-oxygen-based molecules / atoms 15 is located upstream of the catalyst unit 11. , Receives the electron beam 9 in the duct.
A part of the oxygen-based molecule / atom 14 is changed to ozone 14 '. Microorganism carcass-adhered dust 13 'and ozone 14' to which the microbial carcasses that have been killed by receiving the electron beam 9 in the duct are attached
Ozone 14 ′ of oxygen molecule / atom 14 and non-oxygen-based molecule / atom 15 is adsorbed by the catalyst unit 11 while permeating through the catalyst unit 11 and decomposed by the catalyst contained in the catalyst unit 11. Return to oxygen-based molecule / atom 14. The concentration of ozone passing through the catalyst unit 11 becomes equal to or less than the allowable value (0.1 ppm). The degree of ozone decomposition depends on the catalyst amount, catalyst temperature, and air volume, but in air conditioning equipment, the air volume and temperature are regulated and are substantially constant, so it is preferable to select the catalyst volume appropriately. .

Dust 13 'attached to dead microorganisms passing through the catalyst unit 11, oxygen-based molecules / atoms 14 and non-oxygen-based molecules /
The microbial carcass attached dust 13 ′ of the atoms 15 is captured by the filter unit 12. The oxygen-based molecule / atom 14 and the non-oxygen-based molecule / atom 15 pass through the filter unit 12 and are returned to the living space such as a hospital room again. Most of the dust 13 'attached to dead microorganisms in the air flow 2 in the duct toward the filter unit 12 is captured by the filter unit 12. In the microbial carcass attached dust 13 ′, microorganisms that have survived without being killed are attached. If the air flow 2 in the duct is in a dry state while maintaining the humidity in a steady state, residual microorganisms will not grow and propagate in the filter unit 12. For breeding, (1) The number of individuals per unit area or unit volume is equal to or more than a threshold value (2) The breeding area is kept at an appropriate humidity (3) The breeding area is appropriate It is necessary that at least four conditions of being kept at the temperature (4) having a proper amount of nutrients in the fertile area are simultaneously satisfied. Nosocomial infections are known to occur if all conditions are met by chance. Condition (2), condition (3), and condition (4) are rarely met at the same time. In principle, the condition (1) is never satisfied even if the condition (2), the condition (3), and the condition (4) are simultaneously satisfied. In the conventional air conditioning system, a small number of filter units 12 out of the enormous amount of filter units 12 have a certain number of individuals or more (more than a threshold value).
There may be a bacterial group of. Condition (2),
When (3) and (4) are coincidentally fulfilled at the same time, the bacterial population of a certain number or more is certainly propagated.

In the present invention, the filter unit 12 to which the bacterial group of a certain number N or more is attached is reliably and statistically reliably irradiated with the electron beam 9 in the duct, and receives the electron beam 9 in the duct. The number N'of living microorganisms in the bacterial population of the filter unit 12 is significantly smaller than N:
N '<< N. Therefore, the probability that microorganisms propagate in the filter unit 12 is statistically zero. The synergistic effect of the electron beam killing effect and the filter capturing effect makes the breeding probability substantially zero. One of the conditions (2), (3), and (4) will not be satisfied soon, and microorganisms that do not reproduce but remain alive will eventually be annihilated and will be in a state close to annihilation.

The distance L between the electron beam emitting surface 8 and the opposing wall of the duct 1 is minimized and can be matched to the depth L1 or L2 shown in FIG. It is important to select the electron beam energy corresponding to the distance L1 or L2. It is important that the absorbed dose is a certain value or more during the effective reach of the electron beam 9 in the duct. As shown in FIG. 2, the flight distance of the electron beam 9 in the duct is shorter than the first threshold distance D1, and the first flow region R1 of the air flow 2 in the duct,
In the second flow region R2 of the duct airflow 2 in which the flight distance of the electron beam 9 in the duct is longer than the second threshold distance D2, the absorbed dose Q1
May be less than the absorbed dose threshold K. In such a case, the ineffective rate of the microorganisms of the dust 13 contained in a part of the air flow 2 in the duct passing through the second flow region R1 and the second flow region R2 is insufficiently small. It is important that the absorbed dose Q2 is a certain value or more at both end points of the flight path of the electron beam 9 in the duct. That the absorbed dose Q2 is a certain value or more at both ends of the flight path of the electron beam 9 in the duct means that the absorbed dose is a certain value or more at all flight arrival points, as shown in FIG. 17 and FIG. Have a necessary and sufficient relationship with. It is not possible to control the absorbed dose above a certain value at all flight arrival points simply by having a large amount of energy.

As shown in FIG. 17, the electron beam emitting surface 8
It has the minimum absorbed dose (on the plane where the flight distance is 0). In order for the electron beam extraction window 7 to have such a minimum absorbed dose, it is important that the electron beam extraction window 7 has a deceleration plate for decelerating the electron beam 5.

FIG. 3 shows another embodiment of the radiation irradiation apparatus according to the present invention. In the present embodiment, a pre-filter 16 is additionally arranged as another filter unit on the upstream side of the catalyst unit 11 of the above-described embodiment. Most of the dust 13 'attached to the microbial carcasses is captured by the prefilter 16. Pre-filter 16
Dust in the air flow 2 in the duct passing through
The decrease of 3 ′ suppresses the loss of the catalytic function of the catalytic unit 11. The pre-filter 16 has a relatively small trapping rate, but is cheaper than the non-oxygen-based molecule / atom 15.
Is relatively more expensive but has a higher capture rate (HEPA filter), which is effective in improving performance and cost efficiency.

FIG. 4 shows still another embodiment of the radiation irradiation apparatus according to the present invention. In the present embodiment, the filter unit 12 of the embodiment of FIG. 1 is rearranged and arranged from the downstream side of the electron beam irradiator 3 to the upstream side of the electron beam irradiator 3. All conditions (1), (2), (3),
In the situation where (4) happens to be all the same and the probability of nosocomial infection is not zero in the conventional case, bacterial propagation may occur in the filter unit 12. The bacterial group propagated in the filter unit 12 leaks from the filter unit 12 and flows out to the downstream side. Filter unit 1
The bacteria-group-adhered dust 13 ″ to which the bacteria group saturably propagated on the outer surface of the dust flowing from 2 adheres receives the electron beam 9 in the duct. The number N of bacteria groups adhered to the dust 13 ″ Is significantly reduced to a population number N ′ by the bacterial group receiving electron beam 9 in the duct: N ′ << N. There is no illness in people who inhale N'of dust. The medical preventive effect of the embodiment of FIG. 1 of the embodiment is medically substantially equivalent to the medical preventive effect of the embodiment of the present invention (unless a group of bacteria with a certain population density or more is inhaled In the point that does not reach,
Same effect. ).

FIG. 5 shows still another embodiment of the radiation irradiation apparatus according to the present invention. In the present embodiment, the pre-filter 16 of the embodiment shown in FIG.
It is rearranged from the downstream side to the upstream side of the electron beam irradiator 3. Dust 13 'whose number (density) is reduced to N'when receiving electron beam 9 in the duct
Are trapped in the filter unit 12, but bacterial groups do not propagate in the filter unit 12. As described above, the pre-filter 16 ′ of the present embodiment can extend the life of the catalyst unit 11 and has a small amount of dust in the irradiation area of the electron beam 9 in the duct. By reducing the dose (current amount) of the electron beam extraction window 7, it is possible to reduce the degree of temperature rise due to heating of the electron beam extraction window 7 and further reduce the cost of the electron beam irradiator 3.

FIG. 6 shows still another embodiment of the radiation irradiation apparatus according to the present invention. The present embodiment is improved in terms of the effective flight distance of the electron beam 9 in the duct. The effective flight distance D of the electron beam 9 in the duct is set shorter than the standard distance Ds of the duct 1. The duct portion in which the electron beam irradiator 3 is arranged is deformed so as to be shorter than the other portions in terms of the traveling direction distance (flight distance) of the electron beam 9 in the duct. It is preferable that the flow passage cross-sectional area is the same in all duct portions. It is preferable to increase the length of the curtain-shaped electron beam in the duct 9 in that direction as the cross-sectional length of the flow path in the direction orthogonal to the flow direction increases. The positional relationship between the catalyst unit 11 and the filter unit 12 is
All the forms described in the embodiments can be applied.

As shown in FIG. 17, when the density in the duct does not vary depending on the place, the shorter the flight distance, the smaller the energy (energy at the electron beam emitting surface 8 of one electron) of the smaller energy. The electron beam 9 in the duct has a sufficient bactericidal effect in the entire flight range in the duct. By reducing the flight distance of the electron beam 9 in the duct, the electron beam irradiator 3 that generates the electron beam 5 having lower energy can be used.

Changing the entire duct 1 to have a sectional shape having the same length as the proper flight distance D defined in this manner causes an increase in pressure loss. In order not to cause an increase in pressure loss in the catalyst unit 11 arranged on the downstream side of the electron beam irradiator 3, the duct 1 on the AC side of the electron beam irradiator 3 is used.
The cross-sectional area of is properly determined. As a result of the optimization of the cross-sectional area, the duct area where the electron beam irradiator 3 is not arranged may be larger than the duct area where the electron beam irradiator 3 is arranged. When the cross-sectional area changes in this manner, the curved surface of the inner surface of the duct portion in the changed region may be formed into a curved surface 17 that smoothly changes and is continuous with the front and rear inner surfaces, as shown in FIG. preferable. If the cross-sectional area of the duct portion in which the catalyst unit 11 is arranged is set to be wide, the pressure loss is reduced, and the flow velocity of the air flow 2 in the duct in the catalyst unit 11 is reduced, so that the interaction between ozone and the catalyst is reduced. The probability increases and the processing efficiency improves. When the duct area where the electron beam irradiator 3 is arranged has a wide cross-sectional area on the upstream side and the downstream side, a reducer structure that reduces pressure loss on the upstream side and the downstream side is adopted. Is desirable.

To shorten the flight distance of the electron beam 9 in the duct in consideration of such pressure loss and interaction probability,
The initial energy of the electron beam 9 in the duct can be reduced. The decrease in the initial energy can reduce the equipment cost of the electron beam irradiator 3, and also protects the X-rays generated from the wall of the airflow 2 in the duct by the irradiation of the electron beam 9 in the duct. The cost of shielding measures can be reduced.

FIG. 7 shows still another embodiment of the radiation irradiation apparatus according to the present invention. The atomic number of the atom forming the material of the duct 1 forming the terminal area of flight of the electron beam 9 in the duct or the material of the coating layer 18 covering the duct inside is the same as that of the air flow 2 in the duct in the area other than the area. It is higher than the atomic number of the atoms that form the material. A part of the electron beam 9 in the duct incident on the coating layer 18 formed of such a material with a high atomic number collides with an atom with a high atomic number,
In the coating layer 18, a backscattered electron beam 19 passes through an attenuation scattering process.
As a result, it returns to the duct air flow 2 in the duct 1 in a reflective manner.
There is always a part of the electron beam 9 in the duct, the energy of which is properly regulated, which penetrates into the coating layer 18.
By bouncing back such a part, the part can be effectively used as the absorbed dose. Coating layer 18
The absorption of electrons in the attenuated scattering process in the inside causes the heat generation of the coating layer 18. It is preferable to cool the cover layer 18 or the part of the duct 1 that joins the cover layer 18. That cooling is
Water cooling is preferred.

FIG. 8 shows the relationship between the incident electron beam energy and the reflectance of the electron beam (R Ito et al .: Bull.
Univ. Osaka Pref. 41 (1939) p69). If the energies of the incident electron beams are the same and the thicknesses are the same, the reflectivity of the higher numbered higher atomic number atom is higher than that of the lower numbered lower atomic number atom.
The electron beam range is determined by the density of the substance in which the flight takes place (mainly air in this case) and the energy of the incident position. In the present invention, the flight range of the electron beam is such that the electron beam is allowed to fly from one side of the duct to the opposite side while leaving a certain amount of energy remaining in the duct. Since it is set so that it is always shorter than the distance that a part of the electrons can fly), a part of the electron beam entering the duct always reaches the opposite side, and the high atomic number atom which is the wall on the opposite side. Penetrate into the substance of.

A part of the electron beam penetrating in this way becomes a reflected electron beam 19 and is reflected and again enters the duct air flow 2 and is absorbed by the duct air flow 2. If the range of the reflected electron beam energy is not longer than the flight distance, the reflected electron beam 19 is completely absorbed by the air flow 2 in the duct. The increase of the backscattered electron rate due to the adoption of a material having a higher reflectance is due to the total amount of absorption before reflection and after reflection being changed to the total amount of absorption larger than the amount of electron beam absorption at the incident position shown in FIG. Since it can be maintained in the process, the length D in the duct can be set larger, or the equipment cost of the electron beam irradiator 3 can be further reduced by reducing the incident energy, and further, the cooling can be performed. The scale of the vessel can be reduced.

FIG. 9 shows still another embodiment of the radiation irradiation apparatus according to the present invention. The present embodiment is different from all the embodiments described above in terms of the electron beam emission angle. The electron beam emitting surface 8 is not parallel to the streamline direction of the air flow 2 in the duct. The effective center lines of the electron beam 5 and the electron beam 9 in the duct do not enter at 90 degrees with respect to the flow direction of the air flow 2 in the duct, and therefore, the reflection surface on the opposite side of the duct 1 (the duct 1 on the opposite side). Inner surface: Cylindrical surface or plane) does not enter at 90 degrees. FIG. 10 shows the relationship between the incident angle of an electron beam and the reflectance. The incident angle is defined as 0 degree when the angle between the center line of the electron beam 9 in the duct and the reflecting surface on the opposite side is 90 degrees. As shown in FIG. 10, the reflectance increases as the incident angle increases. The backscattered electron dose of the present embodiment is larger than the backscattered electron dose of the embodiment shown in FIG. 1 or FIG. 7, and the total absorbed dose is large, so that the effect described above is further enhanced.

FIG. 11 shows still another embodiment of the radiation irradiation apparatus according to the present invention. The present embodiment is different from the embodiment of FIG. 9 in the angle of incidence of the electron beam on the opposite side. The electron beam emitting surface 8 is parallel to the streamline direction of the air flow 2 in the duct. The effective center lines of the electron beam 5 and the electron beam 9 in the duct are 90 with respect to the flow direction of the air flow 2 in the duct.
It is incident at a degree. The facing surface 21 that is the incident surface and the reflective surface of the coating layer 18 is not parallel to the streamline direction. The angle between the in-duct electron beam 9 and the reflected electron beam 19 is larger than 0 degree, and the incident angle is larger as in the embodiment of FIG. The backscattered electron dose of the present embodiment is larger than the backscattered electron dose of the embodiment shown in FIG. 1 or FIG. 7, and the total absorbed dose is large, so that the effect described above is further enhanced.

FIG. 12 shows still another embodiment of the radiation irradiation apparatus according to the present invention. A magnet 22 has been added. The magnetic field of the magnet 22 is perpendicular to the streamline of the air flow 2 in the duct and the electron beam traveling direction vector of the electron beam 9 in the duct (its direction matches the direction of the effective center line of the electron beam 9 in the duct). Or they are crossing. The magnet 22 is preferably arranged outside the duct 1, and it is preferable that an electron beam does not enter the magnet 22 and the air flow 2 in the duct does not touch the magnet 22. In this case, the duct 1 is made of a non-magnetic material. A part of the innumerable electrons forming the electron beam 9 in the duct changes its direction irregularly while interacting with the air flow 2 in the duct, and receives a Lorentz force as a whole to draw a circular orbit. Is deflected by receiving an irregular force due to Lorentz force, and strays in the air flow 2 in the duct. Since the range is set to be sufficiently longer than the duct internal distance, the electron beam in the duct 9
Part of the electron beam enters the opposite side, but if there is no magnet 22, the part of the electron beam that enters the opposite side and is invalidated effectively enters the duct air flow 2 while straying in the duct air flow 2. Be absorbed. Such an increase in the amount of absorption promotes the effects described above. Further, the atomic number of the atom of the substance forming the duct air flow 2 is smaller than the atomic number of the atom forming the material of the duct. The braking X-ray dose emitted by electrons upon being braked is smaller as the atomic number of the counterpart atom with which the electrons interact is smaller. Increasing the amount of absorption due to stray electrons has the effect of reducing the braking X-ray dose.

FIG. 13 shows still another embodiment of the radiation irradiation apparatus according to the present invention. In the present embodiment,
A baffle 23 is added. The baffle plate 23 is arranged at a duct portion where the electron beam irradiator 3 is arranged.
The baffle plate 23 is added to change the course of the air flow 2 in the upstream duct and bend the subsequent air flow 2 '. The electron beam 9 in the duct transparently passes through the bending airflow 2 '. Although the pressure loss increases due to the bending of the airflow 2 ′, the dust that moves along with the gas stays in the region where the electron beam 9 in the duct passes for a long time. All the dust always crosses the electron beam 9 in the duct once, but many dusts cross the electron beam 9 in the duct many times. The amount of absorption increases due to the stagnation and the eddy current. Since the direction of the flow path formed by the baffle plate 23 coincides with the direction of the air flow 2'and the direction of the flow path is not orthogonal to the electron beam 9 in the duct, dust stays in the electron beam 9 in the duct. It takes a long time to do so, and the absorption amount further increases. In order to avoid heat generation due to the baffle plate 23 absorbing the electron beam, it is preferable to provide the baffle plate 23 with a cooling structure for actively cooling the baffle plate 23.

In the embodiment shown in FIG. 13, the dust can be uniformly irradiated with the electron beam. In the embodiment shown in FIG. 1, the absorption amount of electrons passing through different positions on the center line of the in-duct electron beam 9 is different as shown in FIG. 17, but any dust moving on such a line is It can absorb a uniform amount of electron beams. The uniform electron beam absorption can reduce the initial electron beam energy. The effect of effectively suppressing the increase in the braking X-ray dose is as described above.

FIG. 14 shows still another embodiment of the radiation irradiation apparatus according to the present invention. The duct 1 has a bending portion 1 ′ that bends at a right angle. In the bent portion 1 ′, the flow direction of the air flow 2 in the duct and the direction of the electron beam 9 in the duct match, or between the flow direction of the air flow 2 in the duct and the direction of the electron beam 9 in the duct. Since the angle is effectively smaller than the right angle, the uniformity of the absorption amount is excellent and the above-described plurality of effects can be easily realized at the same time. In the present embodiment, the electron beam emitting surface 8 is required to have the same cross-sectional shape as the cross-sectional shape that forms the flow path after bending (all dust is temporally in the duct electron beam 9). Can exist for a long time.)

FIG. 15 shows still another embodiment of the radiation irradiation apparatus according to the present invention. The present embodiment is modified so as to have a combined effect (an effect of further reducing the equipment cost of the electron beam irradiator 3) in which the respective advantages of the embodiment of FIG. 6 and the embodiment of FIG. 12 are combined. ing. Since its structure is self-explanatory, its description is omitted.

The above-described embodiment of the radiation irradiation apparatus according to the present invention has been described for a hospital, but the radiation irradiation apparatus according to the present invention is more effectively used in a food manufacturing plant and a drug manufacturing plant. .

[0049]

The radiation irradiating apparatus according to the present invention effectively utilizes the filter so that the filter does not serve as a source of bacteria. The effective reach of the electron beam is appropriately set, and the effective use of the electron beam can be realized.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a radiation irradiation apparatus according to the present invention.

FIG. 2 is a graph showing a range of an electron beam.

FIG. 3 is a sectional view showing another embodiment of the radiation irradiation apparatus according to the present invention.

FIG. 4 is a sectional view showing still another embodiment of the radiation irradiation apparatus according to the present invention.

FIG. 5 is a sectional view showing still another embodiment of the radiation irradiation apparatus according to the present invention.

FIG. 6 is a sectional view showing still another embodiment of the radiation irradiation apparatus according to the present invention.

FIG. 7 is a sectional view showing still another embodiment of the radiation irradiation apparatus according to the present invention.

FIG. 8 is a graph showing reflectance.

FIG. 9 is a sectional view showing still another embodiment of the radiation irradiation apparatus according to the present invention.

FIG. 10 is a graph showing reflectance.

FIG. 11 is a sectional view showing still another embodiment of the radiation irradiation apparatus according to the present invention.

FIG. 12 is a sectional view showing still another embodiment of the radiation irradiation apparatus according to the present invention.

FIG. 13 is a sectional view showing still another embodiment of the radiation irradiation apparatus according to the present invention.

FIG. 14 is a sectional view showing still another embodiment of the radiation irradiation apparatus according to the present invention.

FIG. 15 is a sectional view showing still another embodiment of the radiation irradiation apparatus according to the present invention.

FIG. 16 is an oblique-axis projection view showing a known electron beam irradiation device.

FIG. 17 is a graph showing known increase / decrease in absorbed dose.

[Explanation of symbols] 1 ... duct (first duct) 1 '... second duct 2 ... fluid 3 ... Electron beam irradiator 5 ... Electron beam 7 ... Electron beam extraction window 8 ... Emission surface 9 ... Electron beam in duct 12 ... Filter 13 '... Microorganism-attached particles 18 ... Reflective layer 22 ... Magnet

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Claims (17)

[Claims] 1. A radiation irradiator provided outside a flow path, wherein the radiation irradiator comprises a radiation extraction window for extracting radiation, and the radiation extraction window is in contact with a fluid in the flow path to flow. There is an emission surface that emits in-road radiation into the flow path, and the in-flow radiation is emitted from the emission surface and can reliably fly to the opposing surface of the duct that faces the emission surface. A radiation irradiating device having energy having a possible range when being emitted from the emitting surface. 2. A radiation irradiating apparatus further comprising a filtering device which is provided in the flow channel and removes a substance whose physical properties are changed by radiation in the flow channel from the flow channel. 3. The emission energy of the radiation in the flow path emitted from the emission surface is larger than a first setting energy, and the arrival energy of the radiation in the flow path reaching the facing surface is a second setting energy. The radiation irradiation apparatus according to claim 1 or 2, wherein the second set energy is larger than energy and is not zero. 4. The radiation irradiation apparatus according to claim 3, wherein the first setting energy is substantially equal to the second setting energy. 5. The radiation in the flow channel has an emission line vector at the emission surface, and the emission line vector intersects obliquely with respect to the flow channel formed in the flow channel. 4 radiation irradiation device. 6. The radiation irradiating apparatus according to claim 5, wherein the radiation in the flow channel is obliquely incident on the facing surface. 7. The facing portion forming the facing surface has a reflecting layer, and the atomic number of the atom of the substance forming the reflecting layer is larger than the atomic number of the atom of the substance forming the flow path. Radiation irradiation device. 8. The radiation irradiating apparatus according to claim 7, wherein the radiation in the flow path has an emission line vector at the emission surface, and the emission line vector obliquely intersects the facing surface which is an inner surface of the reflective layer. 9. The apparatus further comprises a baffle plate for obstructing a flow in the flow passage at a flow passage portion of the flow passage in which the radiation irradiator is arranged, and the radiation in the flow passage is an emission line at the emission surface. A vector, and the direction of the emission line vector is substantially parallel to the flow direction of the flow path portion formed by the baffle plate.
The radiation irradiation device according to claim 1, which is selected from 10. The apparatus further comprises a magnet arranged at a flow passage part of the flow passage in which the radiation irradiator is arranged, and a part of the radiation in the flow passage receives a Lorentz force and strays irregularly. The radiation irradiation device according to claim 1, which is selected from 1 to 9. 11. The radiation irradiating device according to claim 1, wherein the filtering device is arranged upstream of the radiation extraction window. 12. The filling device includes a first filter and a second filter, the first filter is disposed downstream of the radiation extraction window, and the second filter is upstream of the radiation extraction window. The radiation irradiation apparatus according to claim 1, wherein the radiation irradiation apparatus is arranged on the side. 13. The method according to claim 1, further comprising a catalyst unit disposed in the flow path for decomposing ozone, wherein the catalyst unit is disposed downstream of the radiation extraction window. Radiation irradiation device of paragraph. 14. A catalyst unit disposed in the flow path for decomposing ozone, the catalyst unit being disposed downstream of the radiation extraction window, wherein the filter is a first filter and a second filter. A filter, the first filter is disposed downstream of the radiation extraction window, the second filter is disposed downstream of the radiation extraction window, the catalyst unit is the first filter and the second The radiation irradiating device according to claim 1, wherein the radiation irradiating device is interposed between filters. 15. The radiation irradiating apparatus according to claim 1, wherein the facing surface is positively cooled. 16. A duct, a filter interposed in the duct for adsorbing fine particles, and an electron beam irradiator arranged outside the duct, wherein the electron beam irradiator extracts an electron beam. An extraction window is provided, the electron beam extraction window has an emission surface that emits an electron beam in the duct into the duct by touching a fluid in the duct, and the duct includes a first duct and the first duct. A second duct that is bent and connected to the first duct on the downstream side of the first duct, and the direction of the flow of radiation in the duct is substantially parallel to the direction of the flow path formed by the second duct. Electron beam irradiation device. 17. All of the electron beams in the duct are the second
The electron beam irradiation device according to claim 16, wherein the electron beam irradiation device is absorbed in the flow path formed by a duct.