Sterilization Method

Abstract

To provide a gas sterilization method and a gas sterilization apparatus for gas in a room in a medical facility or the like.SOLUTION: A gas sterilization method includes a radical seed formation step (a) for generating plasma discharge by bubbling in a liquid to form a radical seed and a radical diffusion step (b) for diffusing the radical in the liquid. The method uses a mechanism for conducting the steps (a) and (b) arranged in the body, and a gas inlet and a gas outlet are installed in the body to ventilate the body with outside air and thus sterilizes a gas in a room. There are provided the gas sterilization method and a gas sterilization apparatus for conducting the gas sterilization method.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a sterilization method, etc. More specifically, the present invention relates to a sterilization method based on the principle of generating radicals, etc. by plasma discharge, which is used for the purpose of cleaning the air inside medical facilities and the like and sterilizing instruments, as well as an apparatus using this method. [Background technology]

[0002] Air purifiers have become widespread as a type of sterilization process, and various related technologies have been disclosed (Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2009-5782 A [Patent Document 2] Patent No. 4467389 DISCLOSURE OF THEINVENTION [Problem to be solved by the invention]

[0004] Patent Document 1 discloses a technology related to an air purifier equipped with an electrostatic atomizer that generates picometer-sized mist. The principle of this air purifier is to supply moisture to an electrode by capillary action and to form a mist containing hydroxyl radicals by applying a high voltage to this electrode. Patent Document 2 discloses technology relating to a sterilization method or device that operates on the principle of releasing particles that are reactive to microorganisms or viruses. Such a sterilization device preferably includes a tank containing water, and is equipped with a discharge means and a release means, and operates on the principle of generating reactive particles such as hydroxyl radicals.

[0005] These prior art technologies are similar in that they apply a voltage to water to generate reactive particles, and are useful in that they can be used safely in ordinary households. However, in these prior art technologies, the voltage is applied only to water, so the reactive particle species that can be generated are limited and the sterilizing power is not very strong.

[0006] In light of the above circumstances, the present invention aims to provide a sterilization method that can generate reactive particles (radical species) more efficiently and reduce power consumption, and also aims to provide a sterilization method that can easily obtain a liquid rich in reactive particles. [Means for solving the problem]

[0007] As a result of intensive research, the inventor came up with a method and device for sterilization by generating reactive particles by performing plasma discharge while adding fine bubbles by bubbling in water, and filling the inside of the device with these reactive particles while circulating them with the air outside the device, thus completing the invention. Furthermore, the inventor came up with a configuration that is equipped with a configuration that can continuously supply liquid such as tap water to the inside, and by subjecting this liquid to plasma discharge, a liquid rich in radical species can be obtained from an outlet pipe at any time, allowing the liquid itself to be used, thus completing the invention.

[0008] The present invention comprises the following configuration. The first aspect of the present invention is a method for sterilizing a gas, comprising the steps of: a) a radical species generation step in which plasma discharge is generated by bubbling in a liquid to generate radical species; b) a radical species diffusion step of diffusing radical species in the liquid; The structure that embodies the steps a and b is provided inside the main body, The gas sterilization method is characterized in that the vehicle is provided with an intake port and an exhaust port, and gas outside the vehicle is ventilated into the vehicle to perform gas sterilization.

[0009] A second aspect of the present invention is the gas sterilization method according to the first aspect, further comprising: c) a spatial plasma discharge step of performing plasma discharge in the space inside the body. The third configuration of the present invention further includes a liquid tank section inside the body as a configuration for realizing the step a, The liquid tank portion, A body for storing liquid; A water supply pipe for supplying liquid to the structure, A drain pipe for draining liquid from the structure, A circulation mechanism for circulating the liquid inside the body, The gas sterilization method according to the first or second configuration, in which the step a is carried out in the liquid tank section. A fourth aspect of the present invention is the gas sterilization method according to the third aspect, wherein the circulation mechanism is implemented by bubbling, a rotor, a circulation pump, or a combination of any one or more of these. A fifth aspect of the present invention is the gas sterilization method according to the third or fourth aspect, in which the drain pipe is connected to a vehicle body and a drain outlet is provided outside the vehicle body.

[0010] A sixth aspect of the present invention is a method for producing a liquid containing radical species through the radical species generation step according to a in the gas sterilization method according to any one of the first to fifth aspects. A seventh aspect of the present invention is a liquid containing radical species, which is produced by using the gas sterilization method according to the fifth aspect and is obtained from a drain outlet.

[0011] The eighth aspect of the present invention is a gas supply device having a gas intake and exhaust port, A liquid tank portion filled with liquid, A gas supply unit capable of supplying gas to the liquid tank unit; A plasma power supply unit for supplying plasma power; A submerged plasma discharge unit that discharges plasma; An air fan that circulates air inside the main body, Equipped with, In the liquid tank section, plasma discharge is performed by a submerged plasma discharge section while bubbling with a gas supplied from a gas supply section, thereby generating radical species, The air fan draws gas outside the main body into the main body through the intake port, and the gas is sterilized by the radical species generated inside the main body and discharged from the exhaust port. The gas sterilization treatment device is characterized by the above.

[0012] A ninth aspect of the present invention is the gas sterilization treatment device according to the eighth aspect, further comprising a spatial plasma discharge unit that generates a plasma discharge in the space within the body. A tenth aspect of the present invention is the air sterilization treatment device according to the eighth or ninth aspect, wherein the gas is air. An eleventh aspect of the present invention is the gas sterilization treatment device according to any one of the eighth to tenth aspects, further comprising a liquid pump for circulating the liquid in the liquid tank section. Effect of the Invention

[0013] The present invention makes it possible to provide a sterilization method that can generate reactive particles more efficiently and reduce power consumption. In other words, by using the present invention, radical species diffuse into the indoor air, causing an oxidation reaction on bacteria throughout the room, and sterilizing the room, creating a sterile environment. In addition, by using the present invention, liquid rich in radical species can be obtained at the appropriate time, and this can be used for cleaning or sterilizing instruments, etc. [Brief description of the drawings]

[0014] [Figure 1] FIG. 2 is a diagram showing an example of the device configuration of a gas sterilization treatment device of the present invention. [Diagram 2] FIG. 2 is a diagram showing an example of the device configuration of a gas sterilization treatment device of the present invention. [Diagram 3] FIG. 2 is a diagram showing an example of the device configuration of a gas sterilization treatment device of the present invention. [Figure 4]FIG. 2 is a diagram showing an example of the device configuration of a gas sterilization treatment device of the present invention. [Diagram 5] FIG. 2 is a diagram showing an example of the configuration of a liquid tank in the gas sterilization treatment device of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] The gas sterilization method of the present invention will now be described.

[0016] The gas sterilization method of the present invention is a gas sterilization method, which comprises: a) a radical species generation step of generating radical species by generating plasma discharge through bubbling in a liquid; and b) a radical species diffusion step of diffusing the radical species in the liquid. The gas sterilization method comprises a structure that embodies steps a) and b) a radical species diffusion step of diffusing the radical species in the liquid, the structure being provided inside a vehicle body, and the vehicle body being provided with an intake port and an exhaust port, and the gas outside the vehicle body is ventilated into the vehicle body to perform the gas sterilization treatment. According to the gas sterilization method of the present invention, for example, bubbles are generated in the liquid tank section, which will be described later, by the sterilization process using plasma, and these bubbles are diffused into the water by the flow rate, whereby bacteria, microorganisms, etc. can be killed by radical atoms (e.g., O, Cl, and H, etc.) and radical molecules (e.g., OH radicals, etc.) (hereinafter, these radical atoms and radical molecules are collectively referred to as "radical species") generated by the plasma. In addition, by taking in gas from outside the body into the body and performing a sterilization process, and discharging it together with the radical species through the outlet, an environment in which gas and radical species circulate can be created outside and inside the body, enabling efficient sterilization.

[0017] In the present invention, as a configuration for embodying step a, it is preferable to have a liquid tank section inside the main body, and it is further preferable that such liquid tank section comprises a main body section for storing the liquid, a water supply pipe for supplying the liquid to the main body section, a drain pipe for discharging the liquid from the main body section, and a circulation mechanism for circulating the liquid inside the main body section. This makes it possible to realize step a within the liquid tank section, and also makes it easier to supply and discharge liquid to the liquid tank section, thereby making it easier and simpler to use the radical-rich liquid created in the liquid tank section.

[0018] In the present invention, the circulation mechanism does not need to be particularly limited as long as it can circulate the liquid in the liquid tank, and various means can be used. Examples of such configurations include bubbling, rotors, and circulation pumps, and these means can be used alone or in combination.

[0019] In the present invention, it is preferable that the drain pipe is connected to the main body and has a drain outlet outside the main body. This makes it easier to obtain liquid rich in radical species from the liquid tank portion, which has the effect of improving the convenience of the present invention. Similarly, the water supply pipe can be configured to have a water supply port on the outside of the body. This makes it easier to supply liquid from the water supply port, which has the effect of improving the convenience of the present invention. In addition, for example, by connecting the water supply port to a water supply, it becomes possible to continuously supply liquid to the liquid tank, which can further improve the convenience and usefulness of the present invention.

[0020] In the present invention, it is preferable to include c) a spatial plasma discharge process for performing plasma discharge in the space inside the structure. This makes it possible to perform plasma discharge in the space inside the structure, which has the effect of enabling radical species generation and air sterilization to be performed simultaneously. In addition, it is possible to combine these sterilization processes in liquid and in space, which reduces the power consumption required for the sterilization process in this invention, and has the effect of enabling air sterilization to be performed at low cost.

[0021] Furthermore, the liquid produced through the radical species generation step (a) of the gas sterilization method of the present invention contains a wealth of radical species due to the plasma discharge, and the produced liquid itself has properties that are useful for sterilization, etc. The type and properties of the radical species contained in the liquid change depending on the liquid used, the additives contained in the liquid, and the applied voltage and time of plasma discharge, etc., and in this respect, since it cannot be specified by the composition, etc., it is specified by the manufacturing method. Also, the liquid does not need to be particularly limited as long as it is useful for generating radical species, and various liquids can be used, but typically water can be used, and tap water can be used. Furthermore, by using the device configuration shown in FIG. 4, the liquid can be easily obtained from a drain outlet provided outside the structure.

[0022] The radical species generated in the present invention are diverse depending on the liquid or gas used, but typically, they can be adjusted as a radical group including at least a hydroxyl radical. In addition, the plasma discharge does not need to be particularly limited as long as a plasma discharge capable of generating radical species is possible, and can be performed by streamer discharge, arc discharge, or the like.

[0023] Furthermore, the gas sterilization treatment apparatus of the present invention is an apparatus that embodies the gas sterilization treatment method, and is equipped with a liquid tank section filled with liquid, a gas supply section capable of supplying gas to the liquid tank section, a plasma power supply section that supplies plasma power, a sub-liquid plasma discharge section that performs plasma discharge, and an air fan that circulates air inside the vehicle, all within a vehicle equipped with a gas inlet and outlet, and is characterized in that in the liquid tank section, plasma discharge is performed by the sub-liquid plasma discharge section while bubbling with gas supplied from the gas supply section, generating radical species, and air outside the vehicle is taken into the vehicle through the inlet by the air fan, and inside the vehicle, the air is sterilized by the generated radical species and discharged from the outlet. That is, the gas sterilization treatment device of the present invention includes an internal configuration capable of plasma treatment and uses a high-voltage plasma device. With this configuration, air is passed over the liquid surface of the liquid tank section (described later) and radical species released from the liquid surface into the air are diffused, making it possible to sterilize bacteria, microorganisms, etc. in the air more efficiently than conventional sterilization treatment using plasma.

[0024] The base contains various components and functions as an outer frame for constructing the gas sterilization treatment device. The base does not need to be particularly limited as long as it has such a function and has an air intake and exhaust port as essential components, and various shapes and materials can be used. Typically, the shape of the container is a box such as a rectangular parallelepiped or cube, and is made of a corrosion-resistant material.

[0025] The liquid tank section plays a role of filling the liquid and performing plasma discharge in the liquid. The liquid tank section does not need to be particularly limited as long as it performs this role, and can have various configurations. The liquid tank section can typically be an open box-shaped member that is resistant to corrosion. Furthermore, the liquid used in the liquid tank section does not need to be particularly limited as long as it can generate useful radical species through plasma discharge, and various liquids can be used. Typically, water can be used, and tap water can be used preferably. This makes it possible to generate radical species containing chlorine together with tap water that has been sterilized with low concentrations of chlorine, which has the effect of improving the performance of the gas sterilization treatment device of the present invention.

[0026] The gas supply section serves to supply gas to the plasma discharge section. The gas supply section does not need to be particularly limited as long as it fulfills this role, and can have various configurations. The gas used in the gas supply section does not need to be particularly limited as long as it is a gas species useful for generating radical species, and various gases can be used. In the gas supply unit, it is preferable that the configuration is an air pump. This makes it possible to take in air from outside the vehicle and supply it to the plasma discharge unit, which has the effect of enabling efficient sterilization of the outside air and generation of radical species. Such a configuration can be the configuration disclosed in JP 2018-092703 A.

[0027] The plasma power supply unit serves to supply high voltage power to the plasma discharge unit. The plasma power supply unit does not need to be particularly limited as long as it fulfills this role, and can have various configurations. As an example, the plasma power supply unit can be equipped with a configuration for increasing voltage and controlling each part of the device. That is, the plasma power supply unit efficiently increases the AC 100V that is normally used, monitors and manages various parameters such as the fan, temperature, and frequency, and notifies the user of any abnormality if one occurs. The plasma power supply unit may also be configured to include all or part of the gas supply unit. In other words, it has the function of supplying gas as well as power supply, and controls both discharge and gas supply in the submerged plasma discharge unit.

[0028] The in-liquid plasma discharge unit serves to perform a plasma discharge in the liquid tank unit while receiving power supply from the plasma power supply unit. The in-liquid plasma discharge unit does not need to be particularly limited as long as it fulfills this role, and can have various configurations. The in-liquid plasma discharge unit can typically be configured to have a pair of electrodes, positive and negative, as well as a gas supply pipe from the gas supply unit. In addition, as the electrode material, for example, tungsten or platinum group metals are preferable in consideration of corrosion resistance, and more preferably platinum group metals such as platinum can be used. Such a configuration can be, for example, the configuration disclosed in JP 2012-152712 A.

[0029] In the present invention, it is preferable to further provide a space plasma discharge section in addition to the liquid plasma discharge section. This makes it possible to perform plasma discharge in the space within the structure, and has the effect of enabling radical species generation and air sterilization treatment to be performed simultaneously. In addition, it is possible to combine the sterilization treatments in liquid and space, which reduces the power consumption required for the sterilization treatment in the present invention, and has the effect of enabling air sterilization treatment to be performed at low cost.

[0030] The air fan plays a role of circulating the air inside the body and discharging the sterilized air and radical species inside to the outside through the outlet. The air fan does not need to be particularly limited as long as it fulfills this role, and can have various configurations.

[0031] The gas sterilization treatment apparatus of the present invention will be described with reference to Figures 1 to 6. Figures 1 to 6 are all diagrams showing examples of the device configuration of the gas sterilization treatment apparatus of the present invention.

[0032] The gas sterilization treatment device in Figure 1 has a liquid tank section inside a body with an intake port and an exhaust port. The liquid tank section also has a submerged plasma discharge section connected to a plasma power supply section and a gas supply section (air pump). In addition, the radical species generated by the submerged plasma discharge section are discharged to the outside of the body through the exhaust port by an air fan.

[0033] The gas sterilization equipment in Figure 2 is equipped with a space plasma discharge unit in addition to the configuration in Figure 1, which enables plasma discharge inside the body. This makes it possible to generate radical species while sterilizing the air outside the body. In addition, plasma discharge in liquid and in space enables efficient generation of radical species, making it possible to operate the equipment with low power and low cost.

[0034] The gas sterilization treatment device in Figure 3 is configured to further include a liquid pump in addition to the configuration in Figure 2. This makes it possible to circulate the liquid in the liquid tank, enabling continuous generation of radical species within the liquid. In such a configuration, the suction port and discharge port of the liquid pump are both provided within the liquid tank portion, and the gas supply portion is connected to the submerged plasma discharge portion.

[0035] The gas sterilization treatment device in Figure 4 is configured to include a water supply pipe and a drain pipe in addition to the configuration in Figure 3. This allows for continuous and easy liquid supply from the water supply pipe. In addition, the liquid in the liquid tank (liquid rich in radical species) can be easily collected from the drain pipe, and this can be used for sterilizing instruments, for example. That is, the radicals themselves disappear quickly, making them difficult to use. However, with this configuration, the liquid in the liquid tank section that has been plasma discharged can be collected instantly, making it possible to collect liquid that retains radical oxidation ability at the appropriate time. Note that, although the water supply pipe in this configuration is directly connected to the liquid tank section, this is not intended to be limiting, and for example, it may be connected to a liquid pump and liquid may be supplied through the liquid pump. The positions of the water supply pipe and the drain pipe are not limited to this configuration. In other words, the water supply pipe and the drain pipe can be placed in the most optimal positions, taking into consideration various conditions such as the size of the liquid tank, the flow rate from the water supply pipe, the configuration of the circulation mechanism, etc. These can be placed upside down, or placed approximately evenly at the top, bottom, or center. EXAMPLES

[0036] <<Performance evaluation of prototype>> 1. Using a prototype with the configuration shown in Figure 3, an evaluation was carried out using the generation ability of OH radicals as an index. 2. Using the prototype, plasma discharge was performed for about 5 hours, and water was collected from the liquid tank. Note that tap water was used as the water in the liquid tank. 3. Measurements were carried out on the collected water according to the following methods. (1) Total active oxygen was measured by the iodometric method. (2) Chlorogenic acid was used as a specific reactant with OH radicals, and its reaction was measured by the iodometric method. (3) The active oxygen concentration of OH radicals was calculated by subtracting the measurement results of (2) from those of (1). 4. The measurement results were as follows. (1) Total active oxygen concentration, 9.1×10 -3 mol / L. (2) OH radical concentration, 4.4×10 -4 mol / L (7,500 ppm). 5. From the above, the generation rate of OH radicals out of the total active oxygen was approximately 4.8%. From these results, it was found that the prototype device can obtain liquid rich in radical species by using tap water, and that the liquid is relatively rich in OH radicals as a radical species.

Claims

1. A gas intake and exhaust port is provided in the housing. A liquid tank portion filled with liquid; a gas supply unit capable of supplying gas to the liquid tank unit; A plasma power supply unit that supplies plasma power; A submerged plasma discharge unit for performing plasma discharge; Equipped with In the liquid tank section, plasma discharge is performed by a submerged plasma discharge section while bubbling with a gas supplied from a gas supply section, thereby generating radical species; A water supply pipe and a drain pipe are connected to the liquid tank portion, The water supply pipe is connected to the water supply port outside the main body. The drain pipe is connected to a drain outlet to the outside of the vehicle, and makes it possible to obtain a liquid containing radical species generated in the liquid tank from the drain outlet. The liquid containing the radical species can be used to clean or sterilize instruments. A gas sterilization treatment device comprising:

2. The gas sterilization treatment device is Equipped with an air fan to circulate air inside the main body, The air fan draws air from outside the main body into the main body through the intake port.

2. The gas sterilization treatment apparatus according to claim 1, wherein the air is sterilized by the radical species generated inside the body and discharged from the discharge port.

3. 3. The gas sterilization treatment device according to claim 1, further comprising a spatial plasma discharge unit for generating plasma discharge in a space within the body.

4. 4. The gas sterilization treatment apparatus according to claim 1, wherein the gas is air.

5. 5. The gas sterilization treatment apparatus according to claim 1, further comprising a liquid pump for circulating the liquid in the liquid tank section.

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