JP2004105300A - Sterilizer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve sterilization efficiency with low energy electron beams to powder. <P>SOLUTION: This sterilizer consists of: a duct 2 for carrying a powder stream 15 using an air stream as a carrying medium; and an electron beam generator 1 for introducing the electron beams into the duct 2 via an electron beam transmitting window 5. Accelerated electrons effectively enters minute particles constituting powdered powdery body to effectively kill microbes which exist in the minute particles. Air for carrying gives electronic scattering property to the electron beams and to sterilize microbes in the air. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a sterilizer, and more particularly to a sterilizer that kills living microorganisms that adhere to powder.
[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 term "fungus" means a bacterium including mold and other fungi, a self-proliferating substance such as a virus, and a chemical substance (microorganism in a broad sense) such as a protein that self-proliferates under the action of another cell.
[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 the treatment 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 ultraviolet irradiation and γ-ray irradiation is expected to be promising. Ultraviolet light, which is an extremely low energy ray, has a limited sterilizing ability due to its low energy. On the other hand, γ-rays, which are high-energy rays, have high microbial permeability and their bactericidal effect is weak for their high energy, and high-energy rays that are not used for sterilization and pass through change the surrounding environment into radioactive substances. The effect of environmental deterioration appears remarkably. The equipment cost of the high energy ray generator is remarkably large. Γ-rays, which are light particles having no charge, pass through an object without attenuation.
[0004]
The present inventors have once again noticed that electron beams exhibit a significant bactericidal effect. The cost of an electron beam generator for generating electron beams is extremely low compared to the cost of a gamma ray generator. Gamma rays are produced by radioactive materials, especially cobalt 60. An electron beam is charged and has low permeability to a substance, and one electron destroys the DNA of a microorganism by a single blow. The energy of such an electron beam (the energy of one electron) can be 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 low energy (for example, 300 keV or less) does not penetrate a flour layer having a thickness of 0.5 mm or more in a state in which flour that is strongly required to be sterilized and put into the market in a large quantity is in a normal distribution process. By increasing the energy, the thickness can be increased, but in any case, the thickness of several mm, which can be practically formed by a belt conveyor, is not transmitted. It is difficult to form a flour layer with a thickness of 0.5 mm or less on the conveyor surface of the belt conveyor. The technology of sterilizing cereals with an electron beam is a recent technology (see the following gazette).
[0006]
It is required to improve the sterilization efficiency of the powder with a low energy electron beam. It is particularly desired to apply a low-energy electron beam to a sterilization target substance in a state where the sterilization efficiency can be improved.
[0007]
[Patent Document 1]
Japanese Patent Publication No. 2000-254486
[Problems to be solved by the invention]
An object of the present invention is to provide a sterilizing apparatus that can establish a technique for improving sterilization efficiency of powder with a low energy electron 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.
[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 comprises a duct (2) for transporting a powder stream (15) using an airflow as a transport medium, and an electron for introducing an electron beam into the duct (2) through an electron beam transmission window (5). And a line generator (1). The accelerated electrons effectively penetrate and penetrate the fine particles constituting the powder, and effectively kill microorganisms existing in the fine particles. The transport air stream (eg, an air stream or an inert gas stream) imparts electron scattering to the electron beam, and also kills microorganisms in the air.
[0011]
A nozzle (13) for jetting the powder stream (15) is effectively added. A compressor (8) for compressing gas to generate an air flow, a supply port (11) for supplying powder, and a mixing chamber (12) connected to the supply port (11) for mixing compressed gas and powder. Is more effective. The mixing chamber (12) is preferably arranged upstream of the nozzle (13). The compressor (8) is preferably arranged upstream of the electron beam transmission window (5).
[0012]
It is effective for energy reduction to arrange a reflector that reflects an electron beam on the side of the inside of the duct where the electron beam transmission window (5) faces. Arranging the electron beam irradiator (1) and the electron beam transmission window (5) on both sides of the duct (2) is more effective for reducing energy. In this case, the electron beam irradiator (1) and the electron beam transmission window (5) are arranged mirror-symmetrically.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Corresponding to the figure, the sterilizing apparatus according to the present invention is provided with an electron beam irradiator in a powder flow duct. As shown in FIG. 1, the electron beam irradiator 1 is connected to a powder flow duct 2 via an electron beam transmission window. The electron beam irradiator 1 includes a vacuum vessel main body 3, an electron withdrawing device 4 having an electron withdrawing electrode for emitting electrons to a vacuum chamber in the vacuum vessel main 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 powder flow path 6 in the powder 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. The thickness of the Ti thin film needs to be 0.1 mm or less, and a thin film of about 12 μm is actually used.
[0014]
The powder flow generator 7 is arranged at an upstream end portion of the powder flow duct 2. The powder flow generator 7 includes an air compression supply 8, an air supply pipe 9 that introduces air into the air compression supply 8, a flour supply pipe 11, and high-pressure air that the air compression supply 8 compresses and sends out. And a mixing chamber 12 for mixing the flour supplied from the flour supply pipe 11, and a powder jet for jetting a powder flow disposed downstream of the mixing chamber 12 and sending the powder flow into the powder flow duct 2. And a generation nozzle 13. As the air compression supply device 8, a blowing fan for compression is preferably used, and a compression turbine (supercharger) including a large number of blade blades may be used.
[0015]
The flour-air mixed jet jet spouted from the wheat jet spout 14 of the powder jet generating nozzle 13 is spouted from the wheat jet spout 14 in an enlarged manner to form a conical flour beam 15. The electron beam generated by the electron beam irradiator 1 and transmitted through the electron beam transmission window 5 flies in a direction substantially orthogonal to the center line of the conical flour beam 15 and has a proper flight distance (range). Incident on the flour beam 15.
[0016]
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 penetrating power, collides with air and is scattered, and scatters through the air layer at an arbitrary point with an effective scattering range angle θ. Such scattering transmission is similar in phenomenon to the diffraction phenomenon of electron waves. The individual particle agglomerates forming the flour stream, which is a flour beam, are preferably adjusted to 0.5 mm or less (the individual solid diameter of the flour is very small). One electron impinging on each powder mass passes through the powder mass. One of the myriad of electrons transmitted through one powder mass hits one individual cell of one of the microorganisms attached to and contained in the powder mass. The electron scattering properties of the air carrying the powder enhances the assurance of passing through all the local points in the specific volume region of the powder flow path 6. The scattered electrons uniformly penetrate all areas and attack all microorganisms. The electron beam flying toward the opposing surface of the electron beam transmission window 5 is energetically attenuated, more and more non-transparent, and more is absorbed by the powder. The light reaches the opposing surface of the line transmitting window 5 at last.
[0017]
In order to effectively use such an electron beam, another electron beam irradiator 1 is arranged to be mirror-symmetrical with respect to the center plane of the powder flow path 6 and added, as shown by a dashed line. Is preferred, and this addition is significantly more effective. The addition of the electron beam irradiator 1 can further reduce the output energy of the two electron beam irradiators 1 (for example, halving), further reduce the apparatus cost, and appear on the peripheral surface of the powder flow duct 2 The device load of the erasing technology for erasing electrons or the shielding technology for shielding X-rays emitted from an electron beam can be reduced.
[0018]
When the addition of the electron beam irradiator 1 is not performed, it is remarkably preferable to dispose an electron beam reflection plate for reflecting the electron beam on the inner surface side of the powder flow duct 2 on the opposite surface of the electron beam transmission window 5. The electron beam reflected by the electron beam reflecting plate permeates again into the powder flow path 6 as a sterilizing electron beam and reenters.
[0019]
The use of an air flow exerts the effect of two birds per stone that simultaneously achieve both physical properties of electron beam scattering and powder transportability. Since the microorganisms in the air are sterilized at the same time, the effect of suppressing the harmful effects of the use of air is further exhibited.
[0020]
It is preferable that three electron beam irradiators 1 are arranged at equal angular intervals around the powder flow duct 2. In this case, the powder flow duct 2 has a regular triangular or circular cross section. The air compression supply 8 can be arranged downstream. In this case, the air compression feeder 8 is structured as a suction turbine. 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 is circular or rectangular in the powder flow path 6. It can be accelerated shaped into an electron beam.
[0021]
The duct 2 is bent, particularly bent at a right angle, and irradiates the powder stream with an electron beam in a direction opposite to the flow from the electron beam transmission window facing directly in front of the flow direction, or Irradiating the powder stream with an electron beam through the electron beam transmission window in a direction following the flow following the flow is remarkably effective in that the electron beam can be used in the entire range.
[0022]
The sterilizer according to the present invention is not limited to flour, and can be applied to cereals in general. The sterilizing apparatus according to the present invention is not limited to cereals in general, but may be oral medicines, pharmaceutical coatings, medical and physiologically active substances such as protein (eg, collagen), human body constituents such as calcium powder, sodium glutamate, and pepper powder. It can be applied to various seasonings, microbial culture agents, powdery intermediate products before liquefaction (eg, coffee powder, kinako), and other substances. The carrier medium is not limited to air, and use of an inert gas (eg, nitrogen gas) is effective.
[0023]
【The invention's effect】
The sterilizing apparatus according to the present invention effectively kills microorganisms adhering to powder and reduces the cost of the apparatus.
[Brief description of the drawings]
FIG. 1 is a sectional view showing an embodiment of a sterilization apparatus according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Electron beam irradiation device 2 ... Duct 5 ... Electron beam transmission window 8 ... Air compressor 11 ... Supply port 12 ... Mixing chamber 13 ... Nozzle 15 ... Powder flow

Claims (8)

A duct that transports the powder stream using gas as a transport medium,
An electron beam generator for introducing an electron beam into the duct through an electron beam transmission window. The sterilizing apparatus according to claim 1, further comprising a nozzle for jetting the powder stream. A compressor that compresses gas to generate an air flow;
A supply port for supplying the powder,
A mixing chamber connected to the supply port for mixing the compressed gas and the powder;
The sterilizer according to claim 2, wherein the mixing chamber is disposed upstream of the nozzle. The sterilizer according to claim 3, wherein the compressor is disposed upstream of the electron beam transmission window. The sterilization apparatus according to claim 1, wherein a reflection plate that reflects an electron beam is disposed on a side of the opposing surface in the duct where the electron beam transmission window opposes. The sterilizer according to claim 1, wherein the electron beam irradiator and the electron beam transmission window are arranged on both sides of the duct. The sterilizer according to claim 6, wherein the electron beam irradiator and the electron beam transmission window are arranged mirror-symmetrically. The sterilization apparatus according to claim 1, wherein the gas is an inert gas.

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