JP4043378B2 - Sterilizer - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sterilizer, and more particularly, to a sterilizer that invalidates the physiological activity of microorganisms in a liquid.
[0002]
[Prior art]
Increasing amounts of medical physiological substances are introduced into the human body, such as pharmaceuticals and foodstuffs, that are introduced into globally networked markets. In the near-future mass production system that is complexly networked, it is important that the medical physiological substances in the human body be kept in a sterile state without any gaps in any process of production, management, distribution, and sales. is there. In order to maintain such sterility, it is important to sterilize in an initial process. Here, sterilization means the invalidation of the medical physiological action of a substance that grows in the human body and adversely affects the human body. Here, the fungus means a self-propagating substance such as a mold, a bacterium including other fungi, and a virus.
[0003]
As sterilization techniques or sterilization techniques, heat sterilization, rapid sterilization, dry sterilization, water washing, and chemical introduction are known. In these sterilization techniques, chemicals, water, and a heating / cooling medium are indispensable, and it is difficult to perform treatment after use (for example, water drainage), resulting in an increase in equipment cost and running cost. Instead of such chemical treatment techniques, physical sterilization techniques by X-ray irradiation and γ-ray irradiation are considered promising. X-rays or γ rays, which are high energy rays, are highly permeable to microorganisms and have a low sterilizing effect for their high energy. High energy rays that are transmitted without being used for sterilization make the surrounding environment a radioactive substance. The changing environmental deterioration effect appears remarkably. The equipment cost of the high energy beam generator is significantly high. X-rays and γ-rays, which are light particles having no charge, pass through the object without being attenuated.
[0004]
The saliency of the sterilizing effect of the electron beam is not actually noticed. The cost of an electron beam generator for generating an electron beam is extremely low compared to the costs of an X-ray generator and a γ-ray generator. X-rays are generated by bremsstrahlung of electron beams. Gamma rays are generated by decay of radioactive materials. An electron beam has a charge and low permeability to a substance, and one electron destroys a microbial cell with a single blow. The energy of such an electron beam (energy of one electron) is preferably 300 keV or less. High energy rays have high permeability, but low energy rays with low permeability have a high microbial destruction effect.
[0005]
Low energy electron beams with low transparency do not penetrate into thick objects. An electron beam of 300 keV or less does not penetrate a liquid layer having a thickness of 0.5 mm or more in a state where drinking water that is strongly sterilized and is put into the market in a large amount is placed in the normal distribution process. As a technique for performing a sterilization treatment on a water stream by an electron beam, there is a recent technique known in Patent Document 1 described later.
[0006]
In such a technique, in order to keep the electron beam effective distance of the liquid flow constant, it is necessary to keep the liquid flow velocity constant or to change the nozzle shape appropriately. Therefore, there is a concern about the generation of a temporally invalid irradiation liquid due to the velocity distribution inherent in the fluid such as a liquid flow.
[0007]
[Patent Document 1]
Japanese Patent Laid-Open No. 3-109986
[Problems to be solved by the invention]
The subject of this invention is providing the sterilizer which can establish the technique which improves sterilization efficiency with the low energy electron beam from which a continuous beam is obtained.
Another object of the present invention is to provide a sterilization apparatus in which a low-energy electron beam is applied to a sterilization target substance in a state where sterilization efficiency can be improved.
Still another object of the present invention is to provide a sterilizing apparatus that is not completely sterilized but realizes a significant reduction in the number of bacteria.
[0009]
[Means for Solving the Problems]
Means for solving the problem is expressed as follows. Technical matters appearing in the expression are appended with numbers, symbols, etc. in parentheses. The numbers, symbols, and the like are technical matters constituting at least one embodiment or a plurality of embodiments of the present invention or a plurality of embodiments, in particular, the embodiments or examples. This corresponds to the reference numbers, reference symbols, and the like attached to the technical matters expressed in the drawings corresponding to. Such reference numbers and reference symbols clarify the correspondence and bridging between the technical matters described in the claims and the technical matters of the embodiments or examples. Such correspondence or bridging does not mean that the technical matters described in the claims are interpreted as being limited to the technical matters of the embodiments or examples.
[0010]
The sterilizer according to the present invention includes a duct (2) for passing a liquid flow, and an electron beam generator (3) for introducing an electron beam flow into the liquid flow in the duct (2) through an electron beam transmission window (5). It consists of and. The electron beam that reliably exhibits the bactericidal effect is limited to a continuous beam. In order to generate a continuous beam, it is essential to reduce the output energy. The electron beam flow is substantially orthogonal to the flow direction of the liquid flow, and the width in the orthogonal direction orthogonal to the flow direction of the liquid flow is approximately equal to the effective flight distance of the electron beam flow. The effective flight distance of the electron beam flow varies depending on the energy of the electron beam. When the electron beam energy is 300 keV, which is the maximum energy capable of generating a continuous beam, the effective flight distance of the electron beam flow is 0.5 mm. Therefore, it is important that the width in the orthogonal direction is 0.5 mm or narrower than 0.5 mm. Thus, a low energy electron beam is effectively utilized by setting the width of the liquid flow narrow. The present invention can reliably exert a sterilizing effect by such low energy.
[0011]
The liquid flow is formed from a first liquid flow portion (7) having a narrow width in the orthogonal direction and a second liquid flow portion (8) having a width in the orthogonal direction wider than the width of the first liquid flow portion (7), The electron beam flow is applied to the first liquid flow site (7). The formation of a partially narrow channel is effective for effective use of electron beam energy. The first liquid flow site (7) is formed upstream of the second liquid flow site (8). The liquid flow further forms a third liquid flow part (9) whose width in the orthogonal direction is wider than the width of the first liquid flow part (7). In this case, the third liquid flow site (9) is formed downstream of the second liquid flow site (8). A flow is formed symmetrically and its flow resistance is reduced.
[0012]
In order to increase the width of the first liquid flow portion (7) having a narrow width in the orthogonal direction and increase the processing amount, there are the following means. The electron beam flow is irradiated from both sides of the liquid flow so as to face the liquid flow in the orthogonal direction. Irradiating from both sides can double the width in the orthogonal direction without increasing the electron beam energy. In this case, it is effective that the electron beam generator (3) and the electron beam transmission window (5) are arranged in mirror symmetry, and the width in the orthogonal direction is from 1.0 mm or 1.0 mm. Narrow is important. Irradiating from both sides means that the electron beam energy can be reduced to half when the width in the orthogonal direction is constant. The energy of the electron beam current can be set to be smaller than 200 keV at the time of transmission through the electron beam transmission window (5). The arrangement of the electron beam reflector that contacts the liquid flow and reflects the electron beam flow on the side facing the electron beam transmission window (5) further promotes the effective use of energy.
[0013]
The configuration of the apparatus directed to reliable electron beam irradiation with respect to the liquid flow is as described above. In sterilization of a circulation channel, the sterilized liquid stream joins a pool such as a pool that is not sufficiently sterilized. For this reason, it is important to consider the sterilization level based on statistics. It does not make sense to completely sterilize the liquid stream. Therefore, it is effective to set the width in the orthogonal direction to be longer than the effective flight distance of the electron beam flow.
[0014]
The sterilizer according to the present invention includes a duct (2) for passing a liquid flow, and an electron beam generator (3) for introducing an electron beam flow into the liquid flow in the duct (2) through an electron beam transmission window (5). It consists of and. The liquid flow is formed of a first liquid flow portion having a narrow width in the orthogonal direction orthogonal to the liquid flow and a second liquid flow portion having a width in the orthogonal direction wider than the width of the first liquid flow portion. The electron beam flow is applied to the first liquid flow site. The narrow flow path is a part that receives irradiation, and an increase in fluid resistance is suppressed. The first liquid flow site is formed upstream of the second liquid flow site. The liquid flow further forms a third liquid flow site whose width in the orthogonal direction is wider than the width of the first liquid flow site, and the third liquid flow site is formed downstream of the first liquid flow site. The narrow flow path that receives the irradiation is limited to a part of the entire flow path, and the reduction of the fluid resistance is suppressed to the maximum. It is important that the width of the first liquid flow site is 0.5 mm or narrower than 0.5 mm.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Corresponding to the figure, the sterilizer according to the present invention is provided with an electron beam generator in the liquid flow duct. As shown in FIG. 1, the electron beam generator 1 is coupled to a liquid flow duct 2 through an electron beam transmission window 5. The electron beam generator 1 includes a vacuum vessel body 3, an electron detacher 4 having an electron detachment electrode that emits electrons to a vacuum chamber in the vacuum vessel body 3, and a detachment from the electron detacher 4 in the vacuum chamber. An accelerating electrode (not shown) for generating an electron beam by accelerating electrons to be generated in the vacuum chamber is constituted. The vacuum chamber is connected to the liquid flow path 6 in the liquid flow duct 2 through the electron beam transmission window 5. A Ti thin film is preferably exemplified as a material for forming the electron beam transmission window 5. The thickness of the Ti thin film is particularly preferably 0.02 mm or less. As the liquid, raw material water such as pharmaceuticals is preferably exemplified.
[0016]
The electron beam is applied to the drinking water in an orthogonal direction generally orthogonal to the flow direction of such raw water. The liquid flow duct 2 includes a first part 7 that is a part irradiated with an electron beam, a second part 8 that is located upstream from the first part 7, and a third part that is located downstream from the first part 7. And form. The width in the orthogonal direction orthogonal to the flow direction of the second part 8 is wider than the width in the orthogonal direction orthogonal to the flow direction of the first part 7. The width in the orthogonal direction orthogonal to the flow direction of the third portion 9 is wider than the width in the orthogonal direction orthogonal to the flow direction of the first portion 7. It is significantly preferable that the energy of the electron beam is 300 keV or lower when it passes through the electron beam transmission window 5. In this case, it is important that the width in the orthogonal direction orthogonal to the flow direction of the first portion 7 is 0.5 mm or narrower than 0.5 mm. Such a restriction is effective not only for water but also for various liquids.
[0017]
The flow velocity of the flow portion corresponding to the first portion 7 is faster than the flow velocity of other portions. Increasing the surface density of the electron beam increases the cost of the electron beam generator 1, but the degree of the effect of the increased cost is so small that it can be ignored.
[0018]
The maximum value of the energy of the electron beam at the time of transmission through the electron beam transmission window 5 is smaller than 300 keV. Such a low energy electron beam has a small transmission power and collides with the water molecules of the raw material water and scatters, and as shown in FIG. 2, the liquid layer is scattered with an effective scattering range angle θ at an arbitrary point. Transparent. Such scattering transmission is similar in phenomenon to the diffraction phenomenon of electron waves. Electrons that do not collide with water molecules continue to permeate while gradually attenuating their energy, fly over an effective flight distance (range), and are absorbed by the opposite duct wall. In this way, the electron beam penetrating in a colliding manner collides with a microorganism in the drinking water and invalidates the physiological activity of the microorganism with a single blow. The electron beam attenuates energetically and becomes increasingly more impervious, more is absorbed by the microorganisms, and the electron beam that is not absorbed to the end finally reaches the opposite surface of the electron beam transmission window 5.
[0019]
As a second form for effective use of such an electron beam, it is remarkably effective that the electron beam generator 1 is arranged mirror-symmetrically with respect to the center plane S of the flow path. This addition is remarkably effective. The addition of the electron beam generator 1 can further reduce the output energy of the two electron beam generators 1, further reduce the apparatus cost, and erase the electrons appearing on the peripheral surface of the liquid flow duct 2. It is possible to reduce the burden on the apparatus of the shielding technique for shielding the X-rays emitted by the technique or the electron beam. Furthermore, such addition allows the thickness of the flow path layer to be doubled or allows the energy of the electron beam to be reduced to a range of 150 keV to 200 ke. Furthermore, such addition allows for a doubling of the flow rate.
[0020]
When the addition of the electron beam generator 1 is not performed, an electron beam reflector (not shown) that reflects the electron beam to the opposite surface of the electron beam transmission window 5 may be disposed on the inner surface side of the liquid flow duct 2. Remarkably preferred. The electron beam reflected by the electron beam reflecting plate penetrates again into the liquid flow path 6 as a sterilizing electron beam and is incident again.
[0021]
It is preferable that the three electron beam generators 1 are arranged at equiangular intervals around the liquid flow duct 2. In this case, the cross section of the liquid flow duct 2 is formed in an equilateral triangle or a circle. The electron beam electrode described above is formed as a wide area grid electrode or a grid electrode so that the cross section of the electron beam is circular or rectangular in the liquid flow path 6, and the electron beam is in the form of an electron beam bundle. It can be accelerated as an electron beam.
[0022]
In the sterilization apparatus according to the present invention, the liquid is not limited to raw water such as pharmaceuticals, and can be generally applied to liquid. The sterilizing apparatus according to the present invention is not limited to drinking water, but can be applied to industrial pure water, internal medicines, pharmaceutical drops, medical physiologically active substances such as water-soluble proteins, microbial cultures, and other liquid substances.
[0023]
【The invention's effect】
The sterilization apparatus according to the present invention can improve the sterilization efficiency with a low energy electron beam.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an embodiment of a sterilizer according to the present invention.
FIG. 2 is an enlarged view of a part of FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 2 ... Duct 3 ... Electron beam generator 5 ... Electron beam transmission window 7 ... 1st liquid flow site | part 8 ... 2nd liquid flow site | part 9 ... 3rd liquid flow site | part

Claims (3)

A duct through which the liquid flows,
An electron beam generator for introducing an electron beam flow into the liquid flow in the duct through an electron beam transmission window;
The electron beam flow is substantially orthogonal to the flow direction of the liquid flow,
The liquid stream is a circulating liquid stream;
The width of the orthogonal direction perpendicular to the flow direction of the liquid flow is wider than the effective flight distance of the electron beam flow,
The electron beam flow is applied to the liquid flow from both sides facing the liquid flow in a direction orthogonal to the liquid flow,
The width of the liquid flow in the direction orthogonal to the flow direction is approximately equal to twice the effective flight distance of the electron beam flow. A duct through which the liquid flows,
An electron beam generator for introducing an electron beam flow into the liquid flow in the duct through an electron beam transmission window;
The electron beam flow is substantially orthogonal to the flow direction of the liquid flow,
The liquid stream is a circulating liquid stream;
The width of the orthogonal direction perpendicular to the flow direction of the liquid flow is wider than the effective flight distance of the electron beam flow,
The liquid flow is
A first liquid flow portion having a narrow width in an orthogonal direction orthogonal to the flow direction of the liquid flow;
A second liquid flow site having a width in the orthogonal direction wider than the width of the first liquid flow site,
The electron beam flow is applied to the first liquid flow site. A duct through which the liquid flows,
An electron beam generator for introducing an electron beam flow into the liquid flow in the duct through an electron beam transmission window;
An electron beam reflector that directly contacts the liquid flow on the side facing the electron beam transmission window and reflects the electron beam flow;
The electron beam flow is substantially orthogonal to the flow direction of the liquid flow,
The liquid stream is a circulating liquid stream;
The width of the liquid flow in the direction orthogonal to the flow direction is wider than the effective flight distance of the electron beam flow.

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