KR20030060644A - Sterilizatoin method using atmospheric plasma - Google Patents

Abstract

The present invention relates to a method for sterilizing pathogenic microorganisms, and more particularly, to a method for sterilization and detoxification using atmospheric plasma.

The method of the present invention is characterized by sterilizing pathogenic microorganisms of an object with active radicals generated by an atmospheric plasma generator comprising a power supply device, a plasma generating reaction tube and a gas supply device.

Therefore, the sterilization method using atmospheric pressure plasma according to the present invention generates plasma by using air, gaseous water, hydrogen peroxide, etc. as the main reaction gas, and thus does not generate harmful substances and is harmless to the environment. There is this. In particular, when a Helmholtz coil or a solenoid coil is installed at the front end of the plasma generating tube, the residual gas can be completely decomposed into active radicals, and the active radicals can be transported to a long distance. In addition, since the sterilization process can be processed in a state in which the to-be-processed object is packaged in a sterilized bag, the sterilization process is convenient, economical, and can be stored for a long time in the sterilized state.

Description

Sterilization method using plasma at atmospheric pressure {Sterilizatoin method using atmospheric plasma}

The present invention relates to a method for sterilizing pathogenic microorganisms, and more particularly, to a method for sterilization and detoxification using atmospheric plasma.

In general, as a conventional method for sterilizing pathogenic microorganisms, a high pressure / high temperature treatment method, a chemical treatment method using ethylene oxide (Ethylene Oxide), an ultraviolet treatment method, a vacuum plasma method, an ozone treatment method and the like are known.

Among them, the high pressure / high temperature treatment method is the most widely used sterilization method using high pressure steam and high temperature hot air, but this method may cause corrosion of fittings in the case of metal, and plastic cannot be used. In addition, the chemical treatment method using ethylene oxide has excellent sterilization treatment at low temperature, but requires attention to handling as a strong flammability and poison, and above all, there is a problem that can leave a toxic residue on the treated product. Therefore, the chemical treatment method requires a process of removing residual substances (toxic substances) for a long time. The ultraviolet treatment method is a method of treating using an ultraviolet lamp, and it is easy to use, but there is a problem in that a part which is not in direct contact with ultraviolet rays is not sterilized. In addition, the ozone treatment method uses ozone with strong sterilizing power, so it is used in a humid environment, so tools made of materials that lack ozone resistance such as rubber or plastic have a problem of corrosion, and the vacuum plasma treatment method uses plasma in a vacuum state. As a method of generating and sterilizing, the liquid or powder cannot be sterilized in vacuum, and the vacuum equipment must be used. Thus, the treatment cost is expensive.

An object of the present invention is to provide a sterilization and detoxification method using atmospheric pressure (atmospheric pressure) plasma technology to solve the above problems.

1 is a schematic diagram of a sterilization system according to the present invention;

2 is an example of a plasma generating apparatus according to the present invention,

3 is another embodiment of the present invention,

4 is a flow chart showing a sterilization procedure according to the present invention.

* Explanation of symbols for main parts of the drawings

102: power supply device 104: gas supply device

106: atmospheric plasma generator

201a, 201b: magnetic field generating coil 202a, 202b, 302, 306: electrode

203: dielectric film 304: injection tube

310: plasma 320: sample

In order to achieve the above object, the method of the present invention, in the sterilization and detoxification method using a plasma, characterized in that the sterilizing pathogenic microorganisms with the active radicals generated by the atmospheric pressure plasma generator.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a schematic diagram of a sterilization system according to the present invention, in which a sterilization system for sterilizing pathogenic microorganisms using plasma at atmospheric pressure and detoxifying a toxic compound is provided with a power supply 102 and a gas supply device 104. The plasma generator 106 generates plasma at atmospheric pressure to sterilize or decontaminate the object to be treated. Here, the plasma generating device 106 is implemented as a plasma generating reaction chamber or a plasma generating reaction tube as described later.

As described above, in the present invention, since atmospheric plasma is used, toxic residues do not occur, and sterilization and detoxification can be quickly performed on all products of various three-dimensional shapes.

2 is an example of a plasma generating apparatus according to the present invention. The plasma generating apparatus 106 according to the present invention includes a chamber including magnetic field generating coils 201a and 201b, electrodes 202a and 202b, and a dielectric film 203. 205) or in the form of a tube.

Referring to FIG. 2, a solenoid coil or a Helmholtz coil may be used as the magnetic field generating coils 201a and 202b, and a DC power supply 102b is applied to generate a magnetic field. The reaction gas is supplied into the chamber 205 by the gas supply device 104, and the reaction gas is activated by the high frequency (RF) power supply 102a applied between the electrodes 202a and 202b to generate plasma. The dielectric film 203 prevents arc discharge from occurring between the two electrodes 202a and 20b when a high voltage is applied to the two electrodes 202a and 202b.

The electrodes 202a and 202b may have various shapes such as a plate-to-plate type, a plate-to-rod type, a rod-to-rod type, a cylinder type, and the like, and the two electrodes 202a and 202b may be arranged to face each other. The counter electrodes are electrically insulated by the dielectric film 203, and the distance between the electrodes is configured to be mutually adjustable up to 1 to 50 mm. In addition, as the material of the electrodes 202a and 202b, copper, aluminum, stainless steel, silver, platinum, and the like having excellent thermal conductivity and high corrosion resistance may be used, and each of the electrodes 202a and 202b is surrounded by a dielectric material. The structure is enclosed, and as the dielectric material, glass, alumina, Teflon, TiO ₂ , BaTiO _3, or the like is used.

The power supply 102a generates an dielectric film discharge by applying an AC power of several hundred volts (KV) to several hundred volts (V) between two electrodes. At this time, the power frequency is 10 ~ 10 ⁹ Hz.

3 is a view showing an example of sterilizing a remote target using a cylinder (cylinder) electrode and a dielectric injection tube as another embodiment of the present invention.

Referring to FIG. 3, the center of the cylindrical tube includes an inner electrode 302 made of a conductive cylindrical rod, and two cylindrical tubes having different diameters are positioned around the inner electrode 302. At this time, the outermost cylindrical tube is an outer electrode 306 made of a conductive material, and the cylindrical tube located between the inner electrode 302 and the outer electrode 306 is an injection tube 304 made of a dielectric material. In FIG. 3, only the cylindrical tube is illustrated, but the structure of the external electrode 306 or the injection tube may be implemented as a polygonal tube in addition to the cylindrical tube, and the internal electrode 302 may be implemented as a cylindrical or polygonal rod. Particularly, in another embodiment of the present invention, the magnetic field generating coil 308 is wound around the electrode to improve the transfer distance r of the plasma 310, thereby increasing the distance to be treated. Water 320 can also be effectively sterilized and detoxified.

Next, the operation of the present invention will be described with reference to the flowchart shown in FIG. 4.

In order to generate the atmospheric plasma according to the present invention, the power supply device (102 of FIG. 1) is operated to supply high frequency power between two electrodes, and a reaction gas is injected (S1, S2). When the reaction gas flows between the two electrodes to which the high voltage is applied, atmospheric pressure plasma is generated by the dielectric film discharge, and sterilization and detoxification are performed on the object to be treated using the plasma (S3 and S4).

Meanwhile, the sterilization and detoxification method according to the present invention includes a method of directly contacting an object with ions, electrons, and active radicals generated in a reaction region of a plasma generating apparatus (FIG. 2), and a gas pressure of a plasma generated in the reaction region. There is a method of transporting the target object to be sterilized and detoxified by spraying the plasma using the injection tube and (Fig. 3). In this case, when the Helmholze coil or the solenoid coil generating the magnetic field is installed in the generating tube or the chamber, the plasma can be effectively transferred to the object to be treated, thereby improving the sterilization and detoxification ability.

In addition, the reaction gas injected into the plasma generating chamber or the tube through the gas injection pipe of the gas supply device 104 includes water in the gas phase (H ₂ O), hydrogen peroxide (H ₂ O ₂ ), alcohol, acetone, argon, hydrogen, helium. , Oxygen, compressed air, and the like may be used, and these reaction gases generate atmospheric pressure plasma by dielectric film discharge when an AC power source of several hundred volts (V) to several tens of kilovolts (KV) is applied between two electrodes in an atmospheric pressure state. At this time, ions, electrons, active radicals, and ozone are generated in the plasma generation region. In particular, as water, hydrogen peroxide, alcohol, acetone, and the like are decomposed in the discharge zone, a large amount of active radicals having excellent oxidizing power is generated to effectively remove bacteria and poisons on the surface of the workpiece within a few seconds within a few minutes.

On the other hand, by uniformly generating a magnetic field by applying power to the Helmholth coil and the solenoid coil so that gaseous gases are completely decomposed into active radicals, sterilization and decontamination can be effectively carried out by transferring the active radicals up to several tens of cm away. have.

The sterilization method of the present invention can sterilize the object by discharging the gas inside the sterilization bag even in a sealed state in which the object is packaged in a sterile bag, so that the object can be stored for a long time.

Experimental Example

Experiment results for the effect of sterilization degree and magnetic field according to the distance after generating the active radicals using the gaseous water for Escheichia coli K-12 using the present invention are shown in Table 1 below.

turn Condition Street 3 cm 10 cm One Air + H ₂ O 3.8 (10) 3 (50) 2 Air + H ₂ O + magnetic field 3.8 (10) 3 Air + alcohol 3.4 (30) 2 (100) 4 Air + alcohol + magnetic field 3.4 (30) 5 Air + H ₂ O ₂ 3.9 (5) 3.9 (5)

Table 1 is inoculated into the LB agar medium of E. coli 100 microliter incubated with 0.3 ~ 0.5 at 600 absorbance in the LB liquid medium, after generating a plasma with the reaction gas of the 'condition' of Table 1, the exposure distance ( 3 cm, 10 cm) was exposed to the medium for 3 minutes (sterilization) and then incubated at 37 ℃ for 16 hours. The number in parentheses is the number of colonies that grew in the medium after treatment, and the number in front of the parentheses indicates the degree of inhibition of the bacteria (hereinafter referred to as the degree of suppression). Value. Thus, inhibition level 4 indicates that the number of colonies is zero (no growth).

In Table 1, the number 1 indicates that plasma is generated using air and H ₂ O as a reaction gas, and then exposed (sterilized) at 3 cm and 10 cm distances for 3 minutes, respectively, and incubated at 37 ° C. for 16 hours. Ten colonies (suppression 3.8) were observed, and 50 colonies (suppression 3) were observed when exposed at 10 cm. In the case of sequence 2, after applying magnetic field to the conditions of sequence 1, 10 colony (inhibition 3.8) was observed after exposure (sterilization) at 10cm distance and incubation at 37 ° C for 16 hours. Therefore, when the magnetic field is applied, even when exposed (sterilized) at a long distance (10cm) it can be seen that the same sterilizing effect as when exposed (sterilized) at a short distance (3cm).

In addition, in Table 1, turn 3 is generated by plasma with air and alcohol as a reaction gas, and then exposed (sterilized) for 3 minutes at 3 cm and 10 cm, respectively, and then incubated at 37 ° C. for 16 hours. Canine colonies (inhibition 3.4) were observed and 100 colonies (inhibition 2) were observed when exposed at 10 cm. In turn 4, 30 colony (inhibition 3.4) was observed as a result of incubating 16 hours at 37 ° C after exposure (sterilization) at 10cm distance after applying magnetic field to the condition of turn 3. In Table 1, the number 5 is a plasma generated by using the reaction gas with air and hydrogen peroxide (H ₂ O ₂ ) and then exposed (sterilized) for 3 minutes at 3cm and 10cm distance, respectively, and incubated at 37 ° C for 16 hours. In this case, five colonies (inhibition 3.9) were observed, and even when exposed at 10 cm, five colonies (inhibition 3.9) were observed.

As a result of Table 1, when the overall exposure distance (sterilization treatment distance) to 10cm, it can be seen that the sterilization effect is reduced than at 3cm, colony under all conditions when applying the magnetic field by the Helmholtz coil It shows the effect of decreasing the number of (colony), it can be seen that the most bactericidal effect in the case of air + hydrogen peroxide.

As described above, the sterilization method using the atmospheric pressure plasma according to the present invention is harmless to the environment because no harmful substances are generated because the plasma is generated by using air, gaseous water, hydrogen peroxide, etc. as the main reaction gases. This is a fast time advantage. In particular, when a Helmholtz coil or a solenoid coil is installed at the front end of the plasma generating tube, the residual gas can be completely decomposed into active radicals, and the active radicals can be transported to a long distance.

In addition, since the sterilization process can be processed in a state in which the to-be-processed object is packaged in a sterilized bag, the sterilization process is convenient, economical, and can be stored for a long time in the sterilized state.

Claims (6)

In the sterilization and detoxification method using plasma, A sterilization method using plasma at atmospheric pressure, characterized by sterilizing pathogenic microorganisms of the object with active radicals generated by the atmospheric pressure plasma generator. According to claim 1, The sterilization method, The atmospheric pressure plasma generating apparatus is a plasma generating apparatus having a chamber, and the plasma is generated at the atmospheric pressure by sterilizing and detoxifying the processed object by active radicals in the chamber after placing the processed object in the chamber. Sterilization method using. The method according to claim 2, wherein when the object is packaged in a sterile bag, the sterilized bag in which the object is packaged is placed in the chamber to generate a plasma to sterilize and detoxify by gas discharge in the sterile bag. Sterilization method using plasma at atmospheric pressure. According to claim 1, The sterilization method, The atmospheric pressure plasma generating apparatus is a plasma generating apparatus having an injection tube, wherein the target object is placed away from the injection tube, and then active radicals are transferred to sterilize and detox the target object. Sterilization method using. 5. The method of claim 4, wherein when the object is packaged in a sterile bag, plasma is applied at atmospheric pressure to sterilize and detox the object by injecting active radicals into the sterile bag in which the object is packaged. Sterilization method used. According to any one of claims 1 to 5, wherein the atmospheric pressure plasma generating apparatus using a gas, such as air, nitrogen, argon, helium, oxygen, and mixed gas thereof as a reaction gas, gaseous water and hydrogen peroxide, A sterilization method using plasma at atmospheric pressure, wherein alcohol or the like can be added.