JP4433296B2 - Active oxygen sterilization apparatus and active oxygen sterilization method - Google Patents

Description

  The present invention relates to an active oxygen sterilizer that is used in various fields such as the medical field, the food field, the sanitary field, and the genetic engineering field that require countermeasures against bacteria.

  Conventionally, sterilizers or sterilizers used in medicine, food, microorganism-related industries, etc. include high-temperature and high-pressure steam sterilizers (autoclave) devices, ethylene oxide gas (EOG) sterilizers, radiation sterilizers using γ rays, etc. There is.

  The high-temperature and high-pressure steam sterilizer uses a method of sterilization (sterilization) with high-temperature and high-pressure steam at about 120 ° C. This high-temperature and high-pressure steam sterilizer can be used when sterilizing metal instruments and the like, but can be used when sterilizing products that are deformed at high temperatures such as plastic containers. Can not.

  The ethylene oxide gas sterilizer uses a method of inactivating pathogens and microorganisms due to the toxicity of ethylene oxide gas. This ethylene oxide gas sterilizer can sterilize plastic containers and the like. However, since ethylene oxide gas has toxicity such as mutagenicity and carcinogenicity, explosiveness, etc., when using the sterilizer, there is a high risk to workers' health and working environment. In addition, there is a problem that it takes a long time for the high concentration ethylene oxide gas used in the treatment to become a low concentration, and the total treatment time becomes long. Moreover, if used gas is released into the atmosphere, it may cause air pollution. Therefore, at present, it is recommended to use an ethylene oxide gas sterilizer only when it is difficult to sterilize by other methods.

  A radiation sterilization apparatus using gamma rays or the like is suitable for sterilizing plastic containers and the like because it has a permeability and does not require heating. However, since it is a radiation, it has a great influence on the human body when exposed to radiation. For this reason, the facility becomes large due to the necessity of reliably managing radioactivity. Therefore, in order to carry out radiation sterilization, it is necessary to purchase a sterilized (sterilized) container from a specialist or to have a sterilized contract.

  Conventionally, an active oxygen sterilization apparatus that includes an ozone supply device, an ultraviolet ray generation lamp, and a stirring device and sterilizes using active oxygen has also been proposed (see, for example, Patent Document 1). In this active oxygen sterilizer, active oxygen is generated by irradiating ozone supplied from an ozone supply device with ultraviolet rays from an ultraviolet ray generation lamp, and the generated active oxygen is used to sterilize containers and the like.

Japanese Patent No. 2555613

  The active oxygen sterilizer can not only sterilize the surface which ultraviolet rays reach directly, but also uses active oxygen, so it can sterilize the inside of the object to be processed. However, in a conventional active oxygen sterilization apparatus, for example, when a medical instrument stored in a bag is sterilized to a sterilization level required in the medical welfare field, a sufficient amount of active oxygen can enter the bag. Therefore, there has been a problem that the sterilization treatment takes time.

  The present invention has been made on the basis of the above circumstances, and an active oxygen sterilizer capable of performing a high sterilization level treatment required in the medical welfare field and the like in a short time with a sufficient amount of active oxygen and an active The object is to provide an oxygen sterilization method.

An active oxygen sterilization apparatus according to the present invention for achieving the above object is an apparatus for sterilizing bacteria attached to an object to be processed with active oxygen in a processing chamber, and an oxygen supply means for supplying a gas containing oxygen into the processing chamber. A first lamp that generates at least ultraviolet light in the vacuum ultraviolet region, a second lamp that generates only ultraviolet light having a wavelength longer than 200 nm, a pressure reducing means for reducing the pressure in the processing chamber, and cooling the processing chamber. Cooling means, and after reducing the pressure in the processing chamber by the pressure reducing means, supplying the oxygen-containing gas into the processing chamber by the oxygen supply means , turning on the first lamp, and ultraviolet is generated active oxygen into the processing chamber by irradiating on the supplied the oxygen into the processing chamber to the front by controlling the temperature of the processing chamber and using the cooling means There row sterilized of said object to be processed by the active oxygen, wherein after completion of the sterilization process, the second of the residual ozone and active oxygen by lamp lit irradiating the ultraviolet to the residual ozone in the processing chamber the process of reducing the concentration is characterized in row Ukoto.

In addition, an active oxygen sterilization apparatus according to the present invention for achieving the above object is an apparatus for sterilizing bacteria attached to an object to be processed with active oxygen in a processing chamber, and supplying oxygen-containing gas into the processing chamber. A supply unit; a first lamp that generates at least ultraviolet rays in a vacuum ultraviolet region; a second lamp that generates only ultraviolet rays having a wavelength longer than 200 nm; a decompression unit that reduces the pressure in the processing chamber; Humidifying means for humidifying, and after the processing chamber is decompressed by the decompression means, the oxygen supply means supplies the oxygen-containing gas into the processing chamber, and the first lamp is turned on. to generate active oxygen into the processing chamber by irradiating the ultraviolet rays to the oxygen supplied into the processing chamber Te, and controls the humidity in the processing chamber using said humidifying means The have rows sterilization of the object to be processed by the active oxygen, the sterilization process after completion of the residual ozone by lit the second lamp irradiating the ultraviolet to the residual ozone in the processing chamber and Te the process of reducing the concentration of active oxygen is characterized in row Ukoto.

In addition, an active oxygen sterilization apparatus according to the present invention for achieving the above object is an apparatus for sterilizing bacteria attached to an object to be processed with active oxygen in a processing chamber, and supplying oxygen-containing gas into the processing chamber. A supply unit; a first lamp that generates at least ultraviolet rays in a vacuum ultraviolet region; a second lamp that generates only ultraviolet rays having a wavelength longer than 200 nm; a decompression unit that reduces the pressure in the processing chamber; A cooling means for cooling and a humidifying means for humidifying the inside of the processing chamber, and after reducing the pressure in the processing chamber by the pressure reducing means, the oxygen supply means supplies the gas containing oxygen into the processing chamber. and, to generate active oxygen into the processing chamber by irradiating the ultraviolet lights the first lamp on the supplied the oxygen into the processing chamber, and the cooling hand There row sterilized of said object to be processed by the active oxygen by controlling the humidity in the processing chamber using said humidifying means to control the temperature of the processing chamber with after completion of the sterilizing treatment, the is characterized in row Ukoto the process to reduce the concentration of the residual ozone and active oxygen by irradiating the second of said ultraviolet light the lamp residual ozone in the processing chamber.

Further, active oxygen disinfection method according to the present invention for achieving the above object, a method for sterilizing microorganisms from the object to be treated by the active oxygen in the process chamber, after the processing chamber in a reduced pressure state, the oxygen A gas containing the active oxygen is supplied to the processing chamber by illuminating the oxygen supplied to the processing chamber by turning on a first lamp that generates at least a vacuum ultraviolet region. is generated in, and row physician sterilized of said object to be processed by the active oxygen by controlling the relative humidity in the processing chamber to about 20-50% to control the temperature of the processing chamber to about 10 to 40 ° C. After completion of the sterilization treatment, the residual ozone is irradiated by illuminating the residual ozone in the processing chamber by turning on a second lamp that generates only ultraviolet rays having a wavelength longer than 200 nm. The process to reduce the concentration of fine active oxygen and is characterized in row Ukoto.

  By controlling the temperature and / or humidity in the processing chamber to a predetermined value, the present invention can increase the concentration of active oxygen in the processing chamber, thereby achieving a high sterilization level required in the medical welfare field and the like. Processing can be performed in a short time.

The best mode for carrying out the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram of an active oxygen sterilizer according to an embodiment of the present invention. As shown in FIG. 1, the active oxygen sterilizer of this embodiment includes a chamber (processing chamber) 10 for storing an object to be processed, and an oxygen supply device (oxygen supply means) for supplying a gas containing oxygen to the chamber 10. 20, a mass flow controller 30 that controls the flow rate (injection speed) of the gas, an active oxygen generation lamp (first lamp) 40, an active oxygen decomposition lamp (second lamp) 50, Blowers 60a and 60b for circulating gas, a vacuum pump (decompression unit) 70 for depressurizing the inside of the chamber 10, an ozone decomposition catalyst 71, a cooling device (cooling unit) 80 for cooling the interior of the chamber 10, and a cooling pipe 81, a humidifying device (humidifying means) 90 for humidifying the inside of the chamber 10, a processing table 11 (not shown) on which an object to be processed is placed, and the temperature and humidity in the chamber 10 are controlled. A control unit (control means) 100 for controlling, a temperature sensor (temperature detection means) 101 for detecting the temperature in the chamber 10, and a humidity sensor (humidity detection means) 102 for detecting the humidity in the chamber 10 are provided. is there. In FIG. 1, the processing table 11 is omitted to simplify the drawing.

  FIG. 2 is a schematic perspective view of the chamber 10 of the active oxygen sterilizer according to the present embodiment, FIG. 3 is a schematic perspective view showing a state in which the workpiece 1 is placed on the processing table 11 of the present embodiment, and FIG. FIG. 5 is a diagram for explaining the light emission distribution of the lamp and oxygen and ozone absorption bands, and FIG. 5 is a diagram for explaining the principle of generating active oxygen. The chamber 10 is for sterilizing the workpiece 1 placed on the processing table 11 using active oxygen. The oxygen supply device 20 supplies a gas containing oxygen into the chamber 10. As the gas containing oxygen, it is desirable to use a gas containing at least the same proportion of oxygen contained in air, that is, a gas in which at least oxygen occupies about 20% (volume). For example, an oxygen gas generator such as air, pure oxygen, or PSA can be used as the gas containing oxygen. The mass flow controller 30 controls the flow rate (injection speed) of the gas supplied from the oxygen supply device 20 into the chamber 10. Specifically, the gas is controlled not to flow into the chamber 10 at a certain flow rate or higher.

  The active oxygen generation lamp 40 generates ultraviolet light in the vacuum ultraviolet region, and the active oxygen decomposition lamp 50 generates ultraviolet light outside the vacuum ultraviolet region. These ultraviolet lamps 40 and 50 are provided in the chamber 10. Here, the ultraviolet ray in the vacuum ultraviolet region means an ultraviolet ray having a wavelength in the range from 200 nm to 1 nm, and the ultraviolet ray outside the vacuum ultraviolet region means an ultraviolet ray having a wavelength in the range from 400 nm to 200 nm.

  Usually, as the ultraviolet ray generation lamps 40 and 50, for example, a low-pressure mercury lamp or an excimer lamp in which xenon gas is sealed is used. FIG. 4 shows the light emission distribution of a general low-pressure mercury lamp. In FIG. 4, the horizontal axis represents wavelength (nm) and the vertical axis represents specific energy (%). In the low-pressure mercury lamp, as shown in FIG. 4, light having a jumping wavelength is output. The main output light is ultraviolet light having a wavelength of 185 nm, a wavelength of 254 nm, a wavelength of 313 nm, a wavelength of 366 nm, and the like. In FIG. 4, the specific energy is the ratio (%) of the energy of the light to the energy of the light having the maximum output wavelength of 254 nm.

  The active oxygen generation lamp 40 and the active oxygen decomposition lamp 50 are essentially the same lamp (for example, a low-pressure mercury lamp), but ultraviolet rays in a desired wavelength region are output to the outside by changing the material of the arc tube. It is adjusted so that. Specifically, as the material of the arc tube in the active oxygen generation lamp 40, for example, ordinary quartz (natural fused quartz glass) or synthetic quartz is used. Since such synthetic quartz or the like also transmits ultraviolet light having a wavelength of 200 nm or less, the active oxygen generation lamp 40 outputs ultraviolet light having a wavelength longer than 200 nm and ultraviolet light having a wavelength of 200 nm or less to the outside. Further, as a material of the arc tube in the active oxygen decomposition lamp 50, for example, quartz glass in which titanium oxide is added to quartz is used. Since such titanium oxide absorbs ultraviolet rays having a wavelength of 200 nm or less, only the ultraviolet rays having a wavelength longer than 200 nm are output from the active oxygen decomposition lamp 50 to the outside. The active oxygen generation lamp 40 may be any lamp that generates at least ultraviolet rays in the vacuum ultraviolet region. As in this example, the active oxygen generation lamp 40 is not limited to ultraviolet rays in the vacuum ultraviolet region and the vacuum ultraviolet region. Those that generate both ultraviolet rays may be used.

  In the active oxygen sterilization apparatus of this embodiment, an object to be processed is sterilized with active oxygen having high reactivity. Such active oxygen is generated using the reaction shown in FIG. FIG. 4 also shows oxygen and ozone absorption bands. For such an absorption band, the vertical axis in FIG. 4 represents the absorption rate. As shown in FIG. 4, oxygen has absorption for ultraviolet rays having a wavelength of 200 nm or less. For this reason, when oxygen receives ultraviolet rays having a wavelength of 200 nm or less, active oxygen is generated by the reaction shown in FIG. In the present embodiment, the reaction shown in FIG. 5A is caused to proceed by ultraviolet rays having a wavelength of 185 nm emitted from the active oxygen generation lamp 40. Further, since active oxygen is unstable, the active oxygen is combined with active oxygen and returned to oxygen again by the reverse reaction of the reaction shown in FIG. 5A, or the reaction shown in FIG. 5B. As a result, active oxygen is combined with oxygen to generate ozone. On the other hand, as shown in FIG. 4, ozone has absorption with respect to ultraviolet rays having a peak near a wavelength of 260 nm. For this reason, when ozone receives ultraviolet rays having a wavelength of around 254 nm, ozone is decomposed into oxygen and active oxygen by the reaction shown in FIG. In the present embodiment, the reaction shown in FIG. 5C is advanced by ultraviolet rays having a wavelength of 254 nm emitted from the active oxygen decomposition lamp 50.

  As described above, in the active oxygen sterilization apparatus of the present embodiment, the active oxygen generation lamp 40 generates ultraviolet rays to generate active oxygen in the chamber 10 using the reaction shown in FIG. be able to. Therefore, the active oxygen sterilizer of this embodiment is different from the conventional active oxygen sterilizer in that a gas containing oxygen is supplied into the chamber 10 and active oxygen is generated from the oxygen. In the conventional active oxygen sterilizer, ozone is supplied into the chamber from an ozonizer or the like, and active oxygen is generated from the ozone.

  The active oxygen generation lamp 40 is desirably provided in the vicinity of the inlet through which oxygen from the oxygen supply device 20 flows into the chamber 10 in order to efficiently irradiate oxygen with ultraviolet rays in the vacuum ultraviolet region.

  The active oxygen decomposing lamp 50 is used for decomposing ozone remaining in the chamber 10 after sterilization. That is, when the active oxygen generation lamp 40 is turned off after the sterilization process is completed, the active oxygen generated by the reaction shown in FIG. 5A is an unstable substance. Ozone is generated by the reaction and remains in the chamber 10. Since the human body is adversely affected if the ozone concentration in the chamber 10 is high, by turning on the active oxygen decomposition lamp 50, the reaction shown in FIG. Can be disassembled. As a result, the ozone concentration in the chamber 10 rapidly decreases, and the active oxygen returns to oxygen by a reaction opposite to the reaction shown in FIG. 5 (a), so that the concentration of active oxygen also decreases rapidly. become. In the active oxygen sterilization apparatus of the present embodiment, ozone and active oxygen remaining in the chamber 10 after sterilization can be easily decomposed, so that a short time after sterilization without waiting for natural disappearance of ozone or the like. Thus, the workpiece 1 can be taken out from the chamber 10. As described above, the active oxygen decomposition lamp 50 plays a role of decomposing ozone after the sterilization treatment to lower the concentration of ozone and active oxygen.

In addition, when ultraviolet rays are irradiated to oxygen in the air, in fact, in addition to ozone (O ₃ ) and active oxygen (O.), a wide variety of active oxygen species including oxygen atoms such as superoxide and hydroxy radicals. Is generated. However, chemical species other than ozone (O ₃ ) and active oxygen (O.) have a small abundance ratio and a short lifetime, so in the above description, for the sake of simplicity, only ozone and active oxygen are included in the active oxygen species. Was taken up and described.

  Further, the ultraviolet ray generating lamps 40 and 50 have a temperature zone of an electrode portion that efficiently radiates ultraviolet rays, and in the case of this lamp, the temperature is about 40 ° C. For this reason, the ultraviolet ray generation lamps 40 and 50 are provided with a dedicated cooling device (not shown) for cooling the electrode portions of the lamps.

  The vacuum pump 70 reduces the pressure in the chamber 10. As the vacuum pump 70, it is sufficient if it has an ability to reduce the pressure in the chamber 10 to about 1 kPa when the atmospheric pressure is set to 100 kPa. For example, a rotary vacuum pump, a scroll vacuum pump, a diaphragm type, etc. A vacuum pump or the like can be used. In the present embodiment, as will be described later, the sterilization process is started after the inside of the chamber 10 is in a reduced pressure state. In the following, the pressure is expressed by assuming that the atmospheric pressure is 100 kPa.

  An ozone decomposition catalyst 71 is provided between the vacuum pump 70 and the chamber 10. As the ozonolysis catalyst 71, for example, a manganese metal catalyst is used. Thereby, it is possible to prevent residual ozone from being discharged to the outside when the gas in the chamber 10 is exhausted.

  The two blower fans 60 are for agitating the gas (including active oxygen) contained in the chamber 10, and as shown in FIG. 2, the blower fan 60 a is placed under the processing table 11 and the blower fan. 60 b is provided in the vicinity of the processing table 11. The blower fan 60 a blows air so that a gas can flow from the bottom surface of the chamber 10 toward the upper lid 10 a of the chamber 10. The blower fan 60 b blows air so that a gas can flow from the upper lid 10 a of the chamber 10 toward the bottom surface of the chamber 10. By these two blower fans 60, the gas in the chamber 10 flows from the bottom to the top of the processing table 11 and flows from the top to the bottom along the inner surface of the chamber 10. That is, in the present embodiment, the gas in the chamber 10 flows from the bottom to the top in the center of the chamber 10 and flows from the top to the bottom in the peripheral side portion of the chamber 10 to circulate in the chamber 10. In this way, by rotating the blower fan 60 and circulating the gas during the sterilization process, the active oxygen in the chamber 10 can be circulated to the shadowed portion of the lamp or the like. The workpiece 1 can also be sterilized effectively.

  The cooling device 80 is for cooling the inside of the chamber 10 and uses a water-cooled chilling unit. In the cooling pipe 81, the coolant (coolant) cooled by the cooling device 80 circulates and flows. The cooling pipe 81 is disposed so as to surround the processing table 11 on which the workpiece 1 in the chamber 10 is placed. In the present embodiment, the cooling pipe 81 is formed as a single pipe so as to surround the processing table 11 on which the workpiece 1 is placed as shown in FIG. 2, but in order to improve the cooling effect, the cooling pipe 81 is double, triple or It does not matter even if it is above.

  The humidifier 90 is for humidifying the inside of the chamber 10, and the ultrasonic humidifier 90 is used in this embodiment. The ultrasonic humidifier 90 is of a type that makes water mist by ultrasonic vibration. In the present embodiment, the ultrasonic vibration type humidifier 90 is used. However, a heating type or the like may be used as long as the inside of the chamber 10 can be humidified.

  A temperature sensor 101 and a humidity sensor 102 are attached in the chamber 10. The controller 100 controls the cooling device 80 based on the temperature in the chamber 10 detected by the temperature sensor 101 to control the inside of the chamber 10 to a predetermined temperature. Further, the control unit 100 controls the humidifier 90 based on the humidity in the chamber 10 detected by the humidity sensor 102 to control the inside of the chamber 10 to a predetermined humidity. In the active oxygen sterilization apparatus of this embodiment, when the active oxygen generation lamp 40 is turned on, the temperature in the chamber 10 is increased by the heat of the lamp, and the temperature in the chamber 10 may become 40 ° C. or higher. When the temperature in the chamber 10 is 40 ° C. or higher, the sterilizing effect due to active oxygen becomes low, and the sterilization process takes time. Further, when the temperature in the chamber 10 is 10 ° C. or lower, the luminous efficiency of the active oxygen generation lamp 40 is extremely lowered, so that a sufficient amount of active oxygen cannot be generated. For this reason, the control part 100 drives the cooling device 80, and controls it so that the temperature in the chamber 10 may become predetermined temperature in the range of about 10-40 degreeC.

  Moreover, in the active oxygen sterilizer of this embodiment, since the inside of the chamber 10 is pressure-reduced, the relative humidity in a chamber will be about 10% or less by this pressure reduction process. Further, even if a gas containing oxygen is supplied after decompression, for example, the gas containing oxygen does not contain moisture, so the relative humidity in the chamber remains low. Furthermore, in the apparatus of this embodiment, the cooling device 80 is driven to cool the inside of the chamber. Then, the cooling pipe 81 piped in the chamber 10 is cooled, condensation occurs in the cooling pipe 81, and the humidity in the chamber 10 further decreases. Thus, when the relative humidity in the chamber 10 falls below 10%, the sterilizing effect by active oxygen is lowered as described later, and the processing takes time. For this reason, in this embodiment, the humidity in the chamber is detected by the humidity sensor 102, and the control unit 100 drives the humidifier 90 based on the detected humidity to humidify the chamber 10. In the apparatus of this embodiment, the humidity in the chamber is maintained at a predetermined humidity within a range of about 20 to 50%.

  As shown in FIG. 3, the processing table 11 is for placing the object to be processed 1 and is a round bar so that the active oxygen circulated by the blower fan 60 can be efficiently distributed to the object to be processed 1. Is formed. The object to be processed 1 is sterilized while being put in the bag 2. The material of the surface of the bag 2 is a flash-spun nonwoven fabric using high-density polyethylene, which is a material that transmits active oxygen or water vapor, such as Tyvek (DuPont, USA). In addition, polypropylene is used as a material for the back surface of the bag 2. In addition, the bag 2 is not restricted to the raw material of this embodiment, What kind of thing may be used if active oxygen permeate | transmits efficiently. For example, it may be a bag using Tyvek (DuPont, USA) on a part of the front and back surfaces, or on both the front and back surfaces.

  Usually, a medical instrument manufacturer sells a medical instrument in a sterilized bag. When using this medical instrument in a medical institution, the bag is broken and the stored instrument is taken out and used. In the present embodiment as well, in order to perform sterilization processing in a state closer to reality, a case will be described below in which sterilization processing is performed in a state where an object 1 such as a medical instrument is placed in a bag 2.

  In addition, when the to-be-processed object 1 is a Teflon (trademark) resin or metal thing which does not produce material deterioration even if it irradiates directly with an ultraviolet-ray, if it irradiates with an ultraviolet-ray directly, the effect and activity by ultraviolet-ray A synergistic effect of the effect of oxygen is obtained, and a higher level of sterilization can be performed quickly. In addition, when the object to be processed 1 is a plastic product or paper product whose material deterioration is a concern due to ultraviolet rays, a metal plate or glass plate that cuts ultraviolet rays so that ultraviolet rays do not directly hit the object to be treated 1 is treated. By disposing it between the object 1 and the ultraviolet lamp, sterilization with active oxygen can be performed while avoiding irradiation with ultraviolet rays.

  Next, a processing procedure for sterilizing an object to be processed in the active oxygen sterilizer according to this embodiment will be described. FIG. 6 is a flowchart for explaining a processing procedure for sterilizing an object to be processed in the active oxygen sterilizer of this embodiment.

  First, the workpiece 1 is placed in a bag 2 using Tyvek (DuPont, USA, registered trademark) on one side, and the bag 2 is placed on the processing table 11 in the chamber 10 (S1). Next, the pressure in the chamber 10 is reduced by the vacuum pump 70 (S2). For example, the pressure in the chamber 10 is reduced to 1 kPa. Thereafter, a gas containing oxygen is supplied from the oxygen supply device 20 into the chamber 10, and the active oxygen generation lamp 40 is turned on (S3). Thereby, the reaction shown in FIG. 5A occurs, and active oxygen is generated in the chamber 10. At this time, after the inside of the chamber 10 is depressurized, a gas containing oxygen is supplied from the oxygen supply device 20 into the chamber 10, so that the gas containing oxygen flowing into the chamber 10, the generated active oxygen, etc. It spreads rapidly to all parts of 10. For this reason, for example, when sterilizing the object to be processed 1 placed in the bag 2, if the active oxygen or the like is sufficiently introduced into the bag 2 or if the cylindrical object to be processed 1 is sterilized, the object to be processed Active oxygen or the like can be distributed to the inside of the object 1.

  As to how much the inside of the chamber 10 is depressurized by the vacuum pump 70, for example, it is desirable to set the pressure in the chamber 10 to a range from 10 kPa to 0.1 kPa. This is because, in order to be able to depressurize more than 0.1 kPa, the manufacturing cost of the apparatus is increased, and if the pressure in the chamber 10 is reduced to at least about 10 kPa, active oxygen can be diffused to some extent. .

  When the gas containing oxygen is supplied into the chamber 10 in this way, the pressure in the chamber 10 gradually returns to atmospheric pressure. And supply of the gas containing oxygen is stopped when predetermined time passes since the supply start of the gas containing oxygen (S4). Here, the predetermined time is a time until the pressure in the chamber 10 reaches a predetermined pressure slightly lower than the atmospheric pressure, for example, 94 kPa. As described above, when the gas supply is stopped, the pressure in the chamber 10 is slightly reduced from the atmospheric pressure because the gas in the chamber 10 may leak to the outside if the atmospheric pressure is increased. It is. At this time, the active oxygen generation lamp 40 is kept lit.

  After the supply of the gas containing oxygen is stopped, the cooling device 80 and the humidifying device 90 are started (S5). If the inside of the chamber is not cooled, the temperature in the chamber 10 may be about 60 ° C. or higher although the temperature in the chamber 10 depends on the outside air temperature due to the lighting of the active oxygen generation lamp 40. Thus, when the inside of a chamber becomes high temperature, the sterilization effect by active oxygen will become low and processing will take time. The sterilizing effect of active oxygen is better as the temperature in the chamber 10 is lower.

  Further, the humidity in the chamber 10 is reduced to about 10% or less due to the reduced pressure, and the gas containing oxygen sent from the oxygen supply device 20 has almost no humidity because it is stored in a dry gas state in a cylinder or the like. Therefore, even if gas is supplied, the humidity in the chamber does not increase. In addition, when the cooling device 80 is driven, dew condensation occurs in the cooling pipe 81, thereby further reducing the humidity in the chamber. As will be described later, when the humidity is lower than 20%, the sterilizing effect is lowered by the active oxygen. For this reason, in this embodiment, the humidity in the chamber 10 is humidified by the humidifier 90 so that the humidity in the chamber becomes a predetermined humidity within a range of 20 to 50%.

  Thereafter, the blower fan 60 is rotated. Thereby, the active oxygen in the chamber 10 can be circulated to a portion or the like that is behind the lamp. Then, the lighting state of the active oxygen generation lamp 40 and the rotation state of the blower fan 60 are maintained for a predetermined time (processing time) (S6). During this time, active oxygen comes into contact with the object to be processed 1 and the sterilization treatment of the object to be processed 1 with active oxygen proceeds. The treatment time generally varies depending on the size of the chamber 10, the sterilization level and shape and size of the workpiece 1, the concentration of active oxygen, the temperature / humidity in the chamber 10, and the like. About a minute is necessary.

  Thus, after a predetermined processing time has elapsed, the active oxygen generation lamp 40 is turned off (S7). Subsequently, the active oxygen decomposition lamp 50 is turned on (S8). By lighting the active oxygen decomposition lamp 50, the concentrations of ozone and active oxygen in the chamber 10 are lowered.

  Then, after a predetermined time has elapsed, the active oxygen decomposition lamp 50 is turned off (S9). Here, the predetermined time is a time required for the concentration of ozone and active oxygen in the chamber 10 to sufficiently decrease. After the active oxygen decomposition lamp 50 is turned off, the blower fan 60 and the humidifier 90 are stopped (S10).

  Next, the processing from step S2 to step S10 is repeated a predetermined number of times (S11). That is, after the gas in the chamber 10 is exhausted by the vacuum pump 70 to reduce the pressure in the chamber 10 (S2), the processing from step S3 to step S10 is subsequently performed. Usually, in the process of step S6, when a predetermined processing time or more elapses, the sterilization effect by active oxygen gradually decreases. This is thought to be because active oxygen is so unstable that it reacts with other substances and disappears. For this reason, in this embodiment, when the desired level of sterilization cannot be performed by a single process from step S2 to step S10, the process from step S2 to step S10 is repeated, and the activation is performed again. It is decided to sterilize with oxygen. For example, when it is desired to perform the sterilization process up to the sterilization level, it is desirable to repeat the above process three times or more. Depending on the size of the chamber 10 and the like, the processing from step S2 to step S10 is performed only once, thereby generating high concentration of active oxygen and sterilizing the workpiece 1 to a desired sterilization level. it can. As a matter of course, in such a case, it is not necessary to repeat the processing from step S2 to step S10 a plurality of times.

  Thus, after the processing from step S2 to step S10 is repeatedly performed a predetermined number of times, the process proceeds to step 12, and the pressure in the chamber 10 is reduced. When the pressure in the chamber 10 decreases, the cooling device 80 is stopped (S13). Finally, by opening the lid of the chamber 10 or the like, air is supplied into the chamber 10 to make the inside of the chamber 10 the same as the atmospheric pressure (S14). Finally, the bag 2 containing the workpiece 1 is taken out from the chamber 10 where the ozone and active oxygen concentrations in the chamber 10 are sufficiently reduced (S15). Thus, the sterilization process is completed.

  Next, the present inventor conducted an experiment to confirm the effect of the sterilization treatment by the active oxygen sterilization apparatus of the present embodiment by actually using microorganisms. This experiment examines the relationship between the temperature and humidity in the chamber and the sterilizing effect of active oxygen. As the chamber 10 in this experiment, a chamber having a space volume of about 50 liters was used. Three active oxygen generating lamps 40 are mounted in the chamber 10. As the active oxygen generation lamp 40, a 200 W U-tube synthetic quartz low-pressure mercury lamp (model QGL200G-3 manufactured by Iwasaki Electric Co., Ltd.) was used. The amount of ultraviolet irradiation per volume is 12 W / liter. The irradiation time was 60 minutes, and the number of treatments was one. As the oxygen supply device 20, a device that supplies pure oxygen was used.

The bacterial species of the sample used in this experiment is Geobacillus Stearothermophylus ATCC7954. A sample inoculated with this bacterial species in a bag 2 of a single-sided Tyvek (DuPont, USA) was used as a sample. This sample was sterilized with the active oxygen sterilizer of this embodiment, cultured in a medium for about 48 hours, and the number of surviving bacteria was counted and measured. In this experiment, it was used with a commercially available bioindicator, the initial bacterial count of 4.0 × 10 ⁶ CFU. CFU is an abbreviation for Colony Forming Unit and represents the number of colonies.

FIG. 7 is a graph showing the results of the first experiment in which the humidity in the chamber was kept at 20% and the temperature was changed to perform the sterilization treatment. In FIG. 7, the horizontal axis represents temperature (° C.), and the vertical axis represents bacterial count (CFU). As shown in FIG. 7, when the humidity in the chamber is kept at 20%, it can be seen that the number of viable bacteria after the sterilization treatment increases as the temperature rises. A closer look to Figure 7, survival bacteria after sterilization from but when the 10 ° C. of around 20 ° C. 10 ⁰ the order of, from 20 near ° C. extremely increased number of bacteria, 40 ° C. vicinity or higher The number of bacteria was on the order of 10 ² , and after 50 ° C., no change was observed from about 2.0 × 10 ² CFU.

From the first experiment, for example, equal to or smaller than the requested order sterilization level bacterial number 10 ¹ is, in the context of the humidity of 20% satisfy the temperature of the required disinfection level, as shown in FIG. 7 It is about 10 ° C. or higher and lower than 25 ° C. For this reason, when the humidity in the chamber 10 is 20%, the effect of the required sterilization level can be obtained by controlling the temperature in the range of 10 ° C. or more and less than 25 ° C. When the temperature was 10 ° C. or lower, the luminous efficiency of the active oxygen generation lamp 40 was extremely reduced, so that the measurement was performed from 10 ° C. or higher.

FIG. 8 is a graph showing the results of a second experiment in which the temperature in the chamber was kept at 40 ° C. and the sterilization treatment was performed while changing the humidity. In FIG. 8, the horizontal axis represents relative humidity (%), and the vertical axis represents the number of bacteria (CFU). As shown in FIG. 8, number of surviving bacteria after sterilization treatment, humidity up to around 20%, and remained at 10 ² on the order, beginning decrease the number of bacteria 20% later in 10 ¹ of the order, humidity However, it is on the order of 10 ¹ up to around 50%. In addition, when the humidity was 50% or later, the number of bacteria increased extremely.

From the second experiment, for example, if the required sterilization level number 10 ² or less bacteria, in a situation where the temperature of the chamber was held at 40 ° C., satisfying humidity required sterilization level, FIG. As shown in FIG. 8, it is 20% or more and 52% or less. For this reason, when the temperature in the chamber 10 is 40 ° C., the required bactericidal effect can be obtained if the humidity is controlled in the range of 20% to 52%.

  In this experiment, the irradiation time of ultraviolet rays was 60 minutes, and the number of treatments was one. However, it is required in the medical welfare field in a shorter time to increase the number of treatments with an irradiation time of 15 minutes to 30 minutes. High bactericidal level bactericidal effect can be obtained. Further, by increasing the irradiation time of the ultraviolet rays, it is possible to use a temperature range wider than the temperature range of the first experiment described above. The same applies to humidity.

  From the results of the first experiment and the second experiment described above, if the temperature in the chamber is in the range of about 10 to 40 ° C., a conventional apparatus that does not control the temperature (the temperature in the chamber is about 60 ° C. In other cases, it takes about 3 hours to obtain the same result under the same experimental conditions.) It was confirmed that the sterilization treatment similar to that of the conventional apparatus can be performed in a much shorter time. In addition, if the relative humidity in the chamber is in the range of about 20% to 50%, a conventional device without humidity control (the humidity in the chamber is 10% or less, and the same result under the same experimental conditions. It was confirmed that sterilization treatment similar to that of the conventional apparatus can be performed in a much shorter time than that of the conventional apparatus.

  Based on the above experimental results, the humidity and temperature are controlled within a predetermined range according to the required sterilization level, which is shorter than the conventional oxygen sterilization treatment apparatus that performs without controlling the temperature and humidity. A sterilizing effect with a high sterilization level required in the medical welfare field or the like can be obtained with a small number of treatments in a short time.

  In addition, this invention is not limited to said embodiment, A various deformation | transformation is possible within the range of the summary. For example, in the above embodiment, the case where both temperature and humidity are controlled has been described. However, the present invention is not limited to this, and only one of temperature and humidity may be controlled. Good.

  In the above embodiment, the case where the control unit controls the temperature and humidity has been described. However, the control unit controls the on / off of the vacuum pump using a relay or the like, or the oxygen supply device using a solenoid valve. It is also possible to control the on / off of the gas supply from.

  In the above embodiment, sterilization of a medical instrument used in the medical welfare field has been described. However, the present invention is not limited to the medical welfare field, and is used in the food field, the hygiene field, and the genetic engineering field. It can also be applied to sterilization of instruments.

  Moreover, although said embodiment demonstrated the case where two ventilation fans were provided, you may make it provide one ventilation fan or 3 or more.

  In the above embodiment, the humidifier and the blower fan are disposed in the chamber. However, the humidifier and the blower fan may be disposed outside the chamber.

  As described above, according to the active oxygen sterilization apparatus of the present invention, the concentration of active oxygen in the chamber can be increased by controlling the temperature and humidity in the chamber, which is required in the medical welfare field and the like. The processing time to a high sterilization level can be shortened as compared with the conventional apparatus. Therefore, the active oxygen sterilizer of the present invention can be applied to sterilization of medical instruments used in the medical welfare field and the like.

It is a schematic block diagram of the active oxygen sterilizer which is one Embodiment of this invention. It is a schematic perspective view of the chamber of the active oxygen sterilizer which is one Embodiment of this invention. It is a schematic perspective view which shows the state which mounted the to-be-processed object on the process stand. It is a figure for demonstrating the light emission distribution of a low pressure mercury lamp, and the absorption band of oxygen and ozone. It is a figure for demonstrating the principle which generates active oxygen. It is a flowchart for demonstrating the process sequence which sterilizes a to-be-processed object in the active oxygen sterilizer of this embodiment. It is a graph which shows the result of the 1st experiment which maintained the humidity in a chamber at 20%, and changed temperature and performed sterilization treatment. It is a graph which shows the result of the 2nd experiment which maintained the temperature in a chamber at 40 degreeC, changed humidity, and performed sterilization.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 To-be-processed object 2 Bag 10 Chamber 11 Treatment stand 20 Oxygen supply apparatus 30 Mass flow controller 40 Active oxygen generation lamp 50 Active oxygen decomposition lamp 60a, 60b Blower fan 70 Vacuum pump 71 Ozone decomposition catalyst 80 Cooling apparatus 81 Cooling pipe 90 Humidifier

Claims (8)

In an apparatus for sterilizing the adherent bacteria of the object to be processed with active oxygen in the processing chamber ,
Oxygen supply means for supplying a gas containing oxygen into the processing chamber;
A first lamp that generates at least ultraviolet rays in the vacuum ultraviolet region;
A second lamp that generates only ultraviolet light having a wavelength longer than 200 nm;
Pressure reducing means for reducing the pressure in the processing chamber;
Cooling means for cooling the processing chamber;
Comprising
After the pressure inside the processing chamber is reduced by the pressure reducing means, the oxygen supply means supplies the oxygen-containing gas into the processing chamber, turns on the first lamp, and supplies the ultraviolet light into the processing chamber. said oxygen to generate active oxygen into the processing chamber by irradiating on, have and row sterilized of said cooling means with controlling the temperature of the processing chamber said object to be processed by the active oxygen, wherein after completion of the sterilization process, the second lamp lit activity, wherein row Ukoto the process to reduce the concentration of the residual ozone and active oxygen by irradiating the ultraviolet to the residual ozone in the processing chamber Oxygen sterilizer. In an apparatus for sterilizing the adherent bacteria of the object to be processed with active oxygen in the processing chamber ,
Oxygen supply means for supplying a gas containing oxygen into the processing chamber;
A first lamp that generates at least ultraviolet rays in the vacuum ultraviolet region;
A second lamp that generates only ultraviolet light having a wavelength longer than 200 nm;
Pressure reducing means for reducing the pressure in the processing chamber;
Humidifying means for humidifying the processing chamber;
Comprising
After the pressure inside the processing chamber is reduced by the pressure reducing means, the oxygen supply means supplies the oxygen-containing gas into the processing chamber, turns on the first lamp, and supplies the ultraviolet light into the processing chamber. wherein to generate active oxygen into the processing chamber by irradiating oxygen, have and row sterilized of said humidifying means the object to be treated by the active oxygen by controlling the humidity in the processing chamber by using the said after completion of the sterilization process, the second lamp lit activity, wherein row Ukoto the process to reduce the concentration of the residual ozone and active oxygen by irradiating the ultraviolet to the residual ozone in the processing chamber Oxygen sterilizer. In an apparatus for sterilizing the adherent bacteria of the object to be processed with active oxygen in the processing chamber ,
Oxygen supply means for supplying a gas containing oxygen into the processing chamber;
A first lamp that generates at least ultraviolet rays in the vacuum ultraviolet region;
A second lamp that generates only ultraviolet light having a wavelength longer than 200 nm;
Pressure reducing means for reducing the pressure in the processing chamber;
Cooling means for cooling the processing chamber;
Humidifying means for humidifying the processing chamber;
Comprising
After the pressure inside the processing chamber is reduced by the pressure reducing means, the oxygen supply means supplies the oxygen-containing gas into the processing chamber, turns on the first lamp, and supplies the ultraviolet light into the processing chamber. It said oxygen to generate active oxygen into the processing chamber by irradiating on, and said cooling means using controls the temperature of the processing chamber by controlling the humidity in the processing chamber using said humidifying means is There row sterilized of said object to be processed by the active oxygen, wherein after completion of the sterilization process, the second of the residual ozone and active oxygen by lamp lit irradiating the ultraviolet to the residual ozone in the processing chamber active oxygen sterilizer characterized rows Ukoto a treatment for reducing the concentration of. Temperature detecting means for detecting the temperature of the processing chamber, and humidity detecting means for detecting the humidity in the processing chamber, together with the temperature detecting means to control said cooling means based on the detected temperature, said humidity detecting means active oxygen disinfection apparatus according to claim 3, characterized in that it comprises a control means for controlling the humidifying means based on the detected humidity. The active oxygen sterilizer according to claim 4 , wherein the control means controls the temperature in the processing chamber to about 10 to 40 ° C and controls the relative humidity in the processing chamber to about 20 to 50%.   6. The active oxygen sterilizer according to claim 1, wherein the article to be processed is sterilized by being put in a bag of flash-spun nonwoven fabric using high-density polyethylene.   7. The active oxygen sterilizer according to claim 1, wherein the gas containing oxygen is pure oxygen. A method for sterilizing microorganisms from the object to be processed in the processing chamber by the active oxygen, after the processing chamber in a reduced pressure state, the gas containing oxygen is supplied into the processing chamber, which generates ultraviolet rays of at least the vacuum ultraviolet region together with the ultraviolet lit one of the lamps by generating active oxygen into the processing chamber by irradiating on the supplied the oxygen into the processing chamber, and controlling the temperature of the processing chamber to about 10 to 40 ° C. said handle relative humidity of the room is controlled to about 20-50% have rows sterilized of said object to be processed by the active oxygen, after completion of the sterilization process, the second wavelength is generated only long ultraviolet than 200nm active oxygen lamp lit in that said row Ukoto the process to reduce the concentration of the residual ozone and active oxygen by irradiating the ultraviolet to the residual ozone in the processing chamber Bacteria method.

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