JP2004236968A - Sterilizer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the efficiency of sterilization by low-energy electronic beam. <P>SOLUTION: This sterilizer is composed of a duct 2 passing a liquid current and an electronic beam generator 3 introducing the electronic beam stream in the liquid current in the duct 2 through an electronic beam transmission window 5. The electronic beam stream intersects substantially perpendicularly to the flow direction of the liquid current, and the orthogonal width intersecting perpendicularly to the flow direction of the liquid current is smaller than the double of the effective flight distance of the electronic beam stream. The sterilization efficiency can be improved by low energy electron beam. The width in the orthogonal direction is approximately equal to the effective flight distance of the electronic beam stream, and the utilization efficiency of the low energy electronic beam is higher. It is important that the width in the orthogonal direction is equal to or less than 0.5 mm. Thus, the width of the liquid current is set smaller and the low energy electronic beam is effectively used. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a sterilizer, and more particularly, to a sterilizer that invalidates the biological activity of microorganisms in a liquid.
[0002]
[Prior art]
BACKGROUND OF THE INVENTION [0002] Medical physiological substances, such as pharmaceuticals and foodstuffs, introduced into globally networked markets are increasing in volume. In the near future, mass-produced mass-production systems are required to ensure that medical and physiological substances put into the human body are kept in a sterile state without any gap in any process of production, management, distribution and sales. is there. In order to maintain such sterility, it is important to sterilize in the initial process. Here, aseptic means disabling the physio-physiological effects of substances that multiply in the human body and adversely affect the human body. Here, the fungus means a self-propagating substance such as a fungus, a bacterium including other fungi, or a virus.
[0003]
As sterilization techniques or sterilization techniques, heat sterilization, rapid cooling sterilization, dry sterilization, water washing, and chemical injection are known. In these sterilization techniques, chemicals, water, and a heating / cooling medium are indispensably used, and processing after use (eg, water drainage) is difficult, resulting in an increase in equipment costs and running costs. Instead of such a chemical treatment technique, a technique of physical sterilization by X-ray irradiation and γ-ray irradiation is expected to be promising. X-rays or γ-rays, which are high-energy rays, have high permeability to microorganisms and have a weak bactericidal effect for their high energy, and high-energy rays that are transmitted without being used for sterilization make the surrounding environment a radioactive substance. The effect of changing the environment worsens remarkably. The equipment cost of the high energy ray generator is remarkably large. X-rays and γ-rays, which are light particles having no charge, pass through an object without attenuation.
[0004]
The remarkable effect of the sterilization effect of electron beams is a fact that has not been noticed much. The cost of an electron beam generator for generating an electron beam is extremely low compared to the cost of an X-ray generator and a γ-ray generator. X-rays are generated by the bremsstrahlung of an electron beam. Gamma rays are produced by the decay of radioactive materials. An electron beam is charged and has low permeability to a substance, and one electron destroys a cell of a microorganism by a single blow. The energy of such an electron beam (the energy of one electron) is preferably 300 keV or less. High energy rays have high permeability, while low energy rays having low permeability have a high microbial destruction effect.
[0005]
Low energy low energy electron beams 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 which is strongly required to be sterilized and put into the market in a large quantity is in a normal distribution process. As a technique for performing a sterilization treatment on a water stream by using 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 appropriately change the nozzle shape. Therefore, there is a concern that a temporally invalid irradiation liquid may be generated due to a velocity distribution inherent in a fluid such as a liquid flow.
[0007]
[Patent Document 1]
JP-A-3-109996
[Problems to be solved by the invention]
It is an object of the present invention to provide a sterilization apparatus that can establish a technology for improving sterilization efficiency with a low energy electron beam that can obtain a continuous beam.
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 the sterilization efficiency can be improved.
Still another object of the present invention is to provide a sterilizing apparatus which is not completely sterilized but realizes a remarkable reduction in the number of bacteria.
[0009]
[Means for Solving the Problems]
Means for solving the problem are expressed as follows. The technical items appearing in the expression are appended with numbers, symbols, etc. in parentheses (). The numbers, symbols, and the like are technical items that constitute at least one embodiment or a plurality of embodiments of the embodiments or the embodiments of the present invention, in particular, the embodiments or the embodiments. Corresponds to the reference numbers, reference symbols, and the like assigned 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 / bridge does not mean that the technical matters described in the claims are interpreted as being limited to the technical matters of the embodiments or the examples.
[0010]
The sterilization apparatus 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 to the liquid flow in the duct (2) through an electron beam transmission window (5). It is composed of Electron beams that reliably and effectively exert a sterilizing effect are limited to continuous beams. In order to generate a continuous beam, it is essential to reduce the output energy. The electron beam flow is substantially perpendicular to the flow direction of the liquid flow, and the width in the orthogonal direction perpendicular to the flow direction of the liquid flow is substantially equal to the effective flight distance of the electron beam flow. The effective flight distance of the electron beam flow depends on the energy of the electron beam. When the electron beam energy is 300 keV, which is the maximum energy at which a continuous beam can be generated, 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 less than 0.5 mm. Thus, by setting the width of the liquid flow to be narrow, the low energy electron beam is effectively used. According to the present invention, a sterilizing effect can be reliably exhibited by such low energy.
[0011]
The liquid flow is formed of 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 larger 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 passage is effective for effective use of electron beam energy. The first liquid flow part (7) is formed upstream of the second liquid flow part (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 part (9) is formed downstream of the second liquid flow part (8). The 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 small width in the orthogonal direction and to increase the processing amount, there are the following means. The electron beam flow is applied from both sides of the liquid flow so as to face the liquid flow in a direction orthogonal to the liquid flow. Such irradiation 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 mirror-symmetrically, and the width in the orthogonal direction is 1.0 mm or 1.0 mm. It is important to be narrow. Irradiation from both sides means that the electron beam energy can be reduced by half when the width in the orthogonal direction is constant. The energy of the electron beam flow can be set to be smaller than 200 keV at the time of passing 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 effective use of energy.
[0013]
The configuration of the device that directs the reliable electron beam irradiation to the liquid flow is as described above. In sterilization of a recirculating channel, the sterilized stream joins a pool, such as a pool, that has not been 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 stream. Therefore, it is rather effective to make the width in the orthogonal direction not less than the effective flight distance of the electron beam flow.
[0014]
The sterilization apparatus 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 to the liquid flow in the duct (2) through an electron beam transmission window (5). It is composed of The liquid flow is formed of a first liquid flow portion having a narrow width in the orthogonal direction perpendicular to the liquid flow, and a second liquid flow portion having a width in the orthogonal direction larger than the width of the first liquid flow portion. The electron beam flow is applied to the first liquid flow site. The narrow channel is a portion to be irradiated, and an increase in fluid resistance is suppressed. The first liquid flow part is formed upstream of the second liquid flow part. The liquid flow further forms a third liquid flow part whose width in the orthogonal direction is wider than the width of the first liquid flow part, and the third liquid flow part is formed downstream of the first liquid flow part. The narrow channel to be irradiated is limited to a part of the entire channel, and the reduction of the fluid resistance is suppressed to the maximum. It is important that the width of the first liquid flow part is 0.5 mm or less than 0.5 mm.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
Corresponding to the figure, the sterilization apparatus according to the present invention has an electron beam generator attached to a liquid flow duct. The electron beam generator 1 is connected to a liquid flow duct 2 through an electron beam transmission window 5 as shown in FIG. The electron beam generator 1 includes a vacuum vessel body 3, an electron withdrawing device 4 having an electron withdrawing electrode that emits electrons to a vacuum chamber in the vacuum vessel body 3, and withdrawing from the electron withdrawing device 4 in the vacuum chamber And an accelerating electrode (not shown) for generating an electron beam by accelerating electrons in the vacuum chamber. The vacuum chamber is connected to a liquid flow path 6 in the liquid flow duct 2 via an electron beam transmission window 5. As a material for forming the electron beam transmission window 5, a Ti thin film is preferably exemplified. It is particularly preferable that the thickness of the Ti thin film is 0.02 mm or less. Preferred examples of the liquid include raw water such as pharmaceuticals.
[0016]
An electron beam is applied to the drinking water in a direction substantially orthogonal to the flow direction of the raw water. The liquid flow duct 2 includes a first portion 7 that is a portion to which the electron beam is irradiated, a second portion 8 located upstream of the first portion 7, and a third portion located downstream of the first portion 7. And form. The width of the second portion 8 in the direction orthogonal to the flow direction is wider than the width of the first portion 7 in the direction orthogonal to the flow direction. The width of the third portion 9 in the direction orthogonal to the flow direction is wider than the width of the first portion 7 in the direction orthogonal to the flow direction. It is remarkably preferable that the energy of the electron beam is 300 keV or lower at the time of passing through the electron beam transmission window 5. In this case, it is important that the width of the first portion 7 in the direction perpendicular to the flow direction is 0.5 mm or less 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 part corresponding to the position of the first part 7 is higher than the flow velocity of the other parts. Increasing the areal density of the electron beam increases the cost of the electron beam generator 1, but the effect of the increase in the cost is negligibly small.
[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 low penetrating power, collides with water molecules of raw material water and is scattered, and as shown in FIG. 2, the liquid layer is scattered at an arbitrary point with an effective scattering range angle θ. Through. Such scattering transmission is similar in phenomenon to the diffraction phenomenon of electron waves. Electrons that do not collide with water molecules continue to penetrate while gradually attenuating their energy, fly over an effective flight distance (range), and are absorbed by the opposing duct wall. The electron beam transmitted in a scattering manner collides with a microorganism in drinking water, and invalidates the biological activity of the microorganism with a single blow. The electron beam is attenuated energetically, becomes increasingly impermeable, more is absorbed by the microorganisms, and the electron beam that is not absorbed to the end reaches the opposite surface of the electron beam transmission window 5 at last.
[0019]
As a second mode for effective use of such an electron beam, it is remarkably effective that the electron beam generator 1 is arranged in mirror symmetry with respect to the center plane S of the flow path. This addition is particularly 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 that appear on the peripheral surface of the liquid flow duct 2. The apparatus load of the technology or the shielding technology for shielding the X-ray emitted from the electron beam can be reduced. Further, such an addition allows the thickness of the flow path layer to be doubled or allows the energy of the electron beam to be reduced to the range of 150 keV to 200 ke. Further, such an 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 reflecting plate (not shown) for reflecting the electron beam on the opposite surface of the electron beam transmitting window 5 may be arranged on the inner surface side of the liquid flow duct 2. Notably preferred. The electron beam reflected by the electron beam reflecting plate permeates again into the liquid flow path 6 as a sterilizing electron beam and reenters.
[0021]
Preferably, three electron beam generators 1 are arranged at equal angular 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 above-mentioned electron desorption electrode is formed as a wide-area grid electrode or grid electrode so that the cross section of the electron beam becomes circular or rectangular in the liquid flow path 6. It can be accelerated shaped as an electron beam.
[0022]
The disinfecting apparatus according to the present invention is not limited to a liquid such as raw water for pharmaceuticals and the like, and can be generally applied to liquids. The disinfection device according to the present invention is not limited to drinking water, and can be applied to industrial pure water, oral medicines, medical infusions, medical and physiologically active substances such as water-soluble proteins, microorganism culture solutions, and other liquid substances.
[0023]
【The invention's effect】
The sterilizer 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 sectional view showing an embodiment of a sterilization apparatus according to the present invention.
FIG. 2 is an enlarged view of a part of FIG. 1;
[Explanation of symbols]
2 duct 3 electron beam generator 5 electron beam transmission window 7 first liquid flow part 8 second liquid flow part 9 third liquid flow part

Claims (9)

A duct through which the liquid flows,
An electron beam generator for introducing an electron beam flow through the electron beam transmission window to the liquid flow in the duct,
A sterilizer in which the electron beam flow is substantially perpendicular to a flow direction of the liquid flow. The sterilizer according to claim 1, wherein a width of the liquid flow in a direction perpendicular to the flow direction is substantially equal to an effective range of the electron beam flow. The sterilizer according to claim 2, wherein a width of the liquid flow in a direction perpendicular to the flow direction is smaller than 0.5 mm or 0.5 mm. The sterilizer according to claim 1, wherein the electron beam flow is applied to the liquid flow from both sides opposed to the liquid flow in a direction orthogonal to the liquid flow. The sterilizer according to claim 1, wherein a width of the liquid flow in a direction orthogonal to the flow direction is approximately equal to twice an effective flight distance of the electron beam flow. The liquid flow is
A first liquid flow portion having a narrow width in a direction perpendicular to the flow direction of the liquid flow,
A second liquid flow portion having a width in the orthogonal direction wider than the width of the first liquid flow portion;
The sterilizer according to claim 1, wherein the electron beam flow is applied to the first liquid flow site. The sterilizer according to claim 1, further comprising an electron beam reflector that directly contacts the liquid flow on a side facing the electron beam transmission window and reflects the electron beam flow. The sterilizer according to claim 1, wherein the liquid flow is a circulation liquid flow. 9. The sterilizing apparatus according to claim 8, wherein a width of the liquid flow in a direction orthogonal to the flow direction is substantially equal to an effective flight distance of the electron beam flow or wider than the effective flight distance.

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