JP4596231B2 - Active oxygen sterilizer - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an active oxygen sterilization apparatus used in the fields of medical care, food, genetic engineering and the like that require measures against bacteria, for example.
[0002]
[Prior art]
Conventionally, sterilizers or sterilizers used in medical, food and microorganism related industries include high-temperature and high-pressure steam sterilization (autoclave) devices, ethylene oxide gas (EOG) sterilizers, radiation sterilizers using γ rays, etc. There is.
[0003]
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.
[0004]
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 sterilization apparatus, 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. Therefore, at present, it is recommended to use an ethylene oxide gas sterilizer only when it is difficult to sterilize by other methods.
[0005]
A radiation sterilization apparatus using gamma rays or the like requires a large facility because of the necessity of managing radioactivity. For this reason, in order to carry out radiation sterilization, it is necessary to purchase equipment from a specialist or entrust it to a specialist.
[0006]
Conventionally, an active oxygen sterilizer including an ozone supply device, an ultraviolet ray generation lamp, and a stirring device 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. At this time, the stirrer is used to circulate active oxygen to a shadowed part such as a lamp.
[0007]
Conventionally, sterilization with ozone has also been performed. In such a sterilization method using ozone, cell walls or cell membranes of bacteria such as Escherichia coli and Bacillus subtilis are dissolved by the oxidizing power of ozone. For this reason, a high level of sterilization effect cannot be obtained unless the ozone concentration is sufficiently high and allowed to act for a long time.
[0008]
[Patent Document 1]
JP-A-1-25865
[0009]
[Problems to be solved by the invention]
By the way, in the conventional active oxygen sterilization apparatus, ozone is supplied into the apparatus main body by the ozone supply apparatus. Therefore, even if active oxygen is generated from the ozone, the ozone concentration in the processing chamber is high, which has an adverse effect on the human body. There are concerns. For this reason, realization of an active oxygen sterilizer capable of performing sterilization while suppressing the ozone concentration in the processing chamber is desired. Moreover, although active oxygen is stirred using the stirring apparatus, there existed a problem that active oxygen could not be entrapped about the inside of an instrument etc., and sufficient sterilization processing could not be performed.
[0010]
The present invention has been made based on the above circumstances, and an object of the present invention is to provide an active oxygen sterilizer capable of performing sterilization while suppressing the ozone concentration in the processing chamber to be low.
[0011]
Another object of the present invention is to provide an active oxygen sterilizer capable of performing an effective sterilization process on the inside of an instrument or the like.
[0012]
[Means for Solving the Problems]
In order to achieve the above object, an active oxygen sterilization apparatus according to claim 1 includes a processing chamber for storing an object to be processed, oxygen supply means for supplying a gas containing oxygen into the processing chamber, and the processing chamber. Pressure reducing means for reducing the pressure of the gas, stirring means for stirring the gas contained in the processing chamber, a first ultraviolet light generating lamp for generating ultraviolet rays in a vacuum ultraviolet region, provided in the processing chamber, and in the processing chamber A second ultraviolet ray generating lamp that generates ultraviolet rays in the far ultraviolet region, and an object to be processed in the processing chamber After is stored , Pressure in the processing chamber by the pressure reducing means Is reduced , Gas containing oxygen from the oxygen supply means But In the processing chamber Supplied Together with In addition, Said first UV generating lamp UV light generated by turning on is absorbed by the oxygen In the processing chamber The processed object is sterilized by the generated active oxygen, The second ultraviolet ray generating lamp UV light generated when is turned on In the processing chamber The active oxygen When Oxygen Combined with Generated ozone By being absorbed into ozone But For oxygen and active oxygen Disassembled , further, Supply of the oxygen-containing gas after a predetermined time has passed before the processing chamber reaches atmospheric pressure Is stopped , Gas in the processing chamber by the stirring means Is being stirred Of the workpiece Sterilization is performed It is characterized by this.
[0013]
According to a second aspect of the present invention, in the active oxygen sterilization apparatus according to the first aspect, the first ultraviolet ray generation lamp after a predetermined processing time has elapsed. Is turned off Then, after a predetermined time has elapsed, the second ultraviolet ray generating lamp Is turned off , afterwards The object to be processed from the processing chamber Is taken out It is characterized by this.
[0014]
The invention described in claim 3 Claim 2 In the described active oxygen sterilizer, From the process of reducing the pressure in the processing chamber by the pressure reducing means, to the process of turning off the second ultraviolet ray generating lamp Is repeated a predetermined number of times.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described 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. FIG. 2 is a diagram for explaining the emission distribution of the low-pressure mercury lamp and the absorption bands of oxygen and ozone, and FIG. 3 is a diagram for explaining the principle of generating active oxygen.
[0018]
The active oxygen sterilizer shown in FIG. 1 includes a chamber (processing chamber) 10, an oxygen supply device 20, a mass flow controller 30, a first ultraviolet ray generation lamp 40, a second ultraviolet ray generation lamp 50, a blower fan ( Agitation means) 60, a vacuum pump (decompression means) 70, and an ozone decomposition catalyst 80.
[0019]
The chamber 10 accommodates an object to be processed. The object to be processed is sterilized in the chamber 10. 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 20.95% (volume). For example, air or pure oxygen can be used as the gas containing oxygen. The mass flow controller 30 controls the flow rate (injection speed) of 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.
[0020]
The first ultraviolet ray generation lamp 40 generates ultraviolet rays in the vacuum ultraviolet region, and the second ultraviolet ray generation lamp 50 generates ultraviolet rays in the far ultraviolet region. These ultraviolet ray generation 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 of 200 nm to 1 nm, and the ultraviolet ray in the far ultraviolet region means an ultraviolet ray having a wavelength in the range of 300 nm to 200 nm.
[0021]
Usually, low-pressure mercury lamps are used as the ultraviolet ray generation lamps 40 and 50. FIG. 2 shows the light emission distribution of a general low-pressure mercury lamp. In FIG. 2, the horizontal axis represents wavelength (nm) and the vertical axis represents specific energy (%). In the low-pressure mercury lamp, as shown in FIG. 2, 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. 2, the specific energy is the ratio (%) of the energy of the light to the energy of the output light having a wavelength of 254 nm.
[0022]
In the first ultraviolet generation lamp 40 and the second ultraviolet generation lamp 50, the wavelength of ultraviolet rays output to the outside is adjusted by changing the material of the arc tube. Specifically, as the material of the arc tube in the first ultraviolet ray generating 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 first ultraviolet light generation lamp 40 outputs ultraviolet light having a wavelength of 200 nm or less as well as ultraviolet light having a wavelength longer than 200 nm to the outside. Further, as the material of the arc tube in the second ultraviolet ray generation lamp 50, for example, quartz glass in which titanium oxide is added to titanium oxide is used. Since such titanium oxide absorbs ultraviolet rays having a wavelength of 200 nm or less, only ultraviolet rays having a wavelength longer than 200 nm are output from the second ultraviolet ray generation lamp 50 to the outside. It should be noted that the first ultraviolet ray generation lamp 40 only needs to generate at least ultraviolet rays in the vacuum ultraviolet region. As in this example, the first ultraviolet ray generation lamp 40 includes ultraviolet rays in the vacuum ultraviolet region and far ultraviolet rays. Those generating ultraviolet rays in the region may be used.
[0023]
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. 2 also shows oxygen and ozone absorption bands. For such an absorption band, the vertical axis in FIG. 2 represents the absorption rate. As shown in FIG. 2, oxygen has absorption with respect to 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. 3A is advanced by the ultraviolet ray having a wavelength of 185 nm emitted from the first ultraviolet ray generation lamp 40. Further, since active oxygen is unstable, the active oxygen combines with the active oxygen by the reverse reaction of FIG. 3A, or returns to oxygen again, or by the reaction shown in FIG. 3B. May combine with oxygen to generate ozone. On the other hand, as shown in FIG. 2, ozone has absorption with respect to ultraviolet rays having a peak near the 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. 3C is advanced by the ultraviolet ray having a wavelength of 254 nm emitted from the second ultraviolet ray generation lamp 50.
[0024]
As described above, in the active oxygen sterilization apparatus of the present embodiment, by simultaneously generating ultraviolet rays from the first ultraviolet ray generation lamp 40 and the second ultraviolet ray generation lamp 50, respectively, FIG. 3 (a), (b), By using each reaction shown in (c), active oxygen can be generated in the chamber 10. 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.
[0025]
The first ultraviolet ray generation lamp 40 is desirably provided in the vicinity of the inlet through which oxygen from the oxygen supply device 30 flows into the chamber 10 in order to efficiently irradiate oxygen in the vacuum ultraviolet region.
[0026]
Further, the second ultraviolet ray generation lamp 50 can be used for the decomposition treatment of ozone remaining in the chamber 10 after the sterilization treatment. That is, after the sterilization process is completed, the second ultraviolet ray generation lamp 50 is turned on with the first ultraviolet ray generation lamp 40 turned off, whereby the reaction of FIG. Can decompose ozone. As a result, the ozone concentration in the chamber 10 rapidly decreases, and the active oxygen returns to oxygen due to the reverse reaction of FIG. 3A, so that the concentration of active oxygen also decreases rapidly. 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 object to be processed can be taken out from the chamber 10. As described above, the second ultraviolet ray generation lamp 50 decomposes ozone generated during the sterilization process to generate active oxygen again, and decomposes ozone after the sterilization process to lower the concentration of ozone and active oxygen. To play a role.
[0027]
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 scroll vacuum pump, a diaphragm vacuum pump, 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.
[0028]
An ozone decomposition catalyst 80 is provided between the vacuum pump 70 and the chamber 10. As the ozonolysis catalyst 80, 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.
[0029]
The blower fan 60 is for stirring the gas (active oxygen) contained in the chamber 10 and is provided in the chamber 10. By rotating the blower fan 60 during the sterilization treatment, the active oxygen in the chamber 10 can be passed to the shadowed portion of the lamp or the like, so that the workpiece placed in the shaded portion is also effective. Can be sterilized.
[0030]
Note that if the blower fan 60 is operated in a high pressure-reduced state, the motor may turn too much and may break. For this reason, the blower fan 60 is rotated after a certain period of time has elapsed after the start of the sterilization process and the pressure in the chamber 10 is close to atmospheric pressure to some extent.
[0031]
Next, a processing procedure for sterilizing an object to be processed in the active oxygen sterilizer according to this embodiment will be described. FIG. 4 is a flowchart for explaining a processing procedure for sterilizing an object to be processed in the active oxygen sterilizer of this embodiment.
[0032]
First, an object to be processed is placed 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 set to 1 kPa. Thereafter, a gas containing oxygen is supplied from the oxygen supply device 30 into the chamber 10, and the first ultraviolet generation lamp 40 and the second ultraviolet generation lamp 50 are turned on (S3). Thereby, each reaction shown in FIG. 3 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 30 into the chamber 10, so that the gas 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 a sample placed in a predetermined bag, active oxygen or the like is sufficiently introduced into the bag, or when sterilizing a cylindrical device or the like, active oxygen or the like is introduced into the device. Can be distributed. Here, the predetermined bag is a bag for putting a sample when sterilization is performed in a high-temperature high-pressure steam sterilizer, an EOG sterilizer, or the like. Such a bag has the property of being permeable to gas. In the present embodiment, the “bag” means the above bag.
[0033]
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. .
[0034]
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 reaches a predetermined pressure slightly lower than the atmospheric pressure, for example, 94 kPa. As described above, the pressure in the chamber 10 is slightly reduced from the atmospheric pressure when the gas supply is stopped because the gas in the chamber 10 may leak to the outside if the atmospheric pressure is increased. It is. At this time, the first ultraviolet ray generation lamp 40 and the second ultraviolet ray generation lamp 50 are kept lit.
[0035]
Thereafter, the blower fan 60 is rotated. Thereby, the active oxygen in the chamber 10 can be circulated to a shadowed portion such as a lamp. Then, the lighting state of the first ultraviolet ray generation lamp 40 and the second ultraviolet ray generation lamp 50 and the rotation state of the blower fan 60 are maintained as they are for a predetermined time (processing time) (S5). During this time, active oxygen comes into contact with the object to be processed, and the sterilization of the object to be processed with active oxygen proceeds. In general, the processing time varies depending on the size of the chamber 10, the size of the object to be processed, the concentration of active oxygen, and the like, but usually requires about 15 to 30 minutes.
[0036]
Thus, after a predetermined processing time has elapsed, only the first ultraviolet ray generation lamp 40 is extinguished while the second ultraviolet ray generation lamp 50 is kept on (S6). That is, by turning on only the second ultraviolet ray generation lamp 50, the concentrations of ozone and active oxygen in the chamber 10 are lowered.
[0037]
Then, after a predetermined time has elapsed, the second ultraviolet ray generation lamp 50 is turned off (S7). Here, the predetermined time is a time required for the concentration of ozone and active oxygen in the chamber 10 to sufficiently decrease.
[0038]
Next, the processing from step S2 to step S7 is repeated a predetermined number of times (S8). 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 S7 is subsequently performed. Usually, in the process of step S5, when a predetermined processing time or more elapses, the bactericidal 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 S7, the process from step S2 to step S7 is repeated, and again, The sterilization treatment with active oxygen is to be performed. 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 S7 is performed only once, so that high concentration of active oxygen can be generated and the object to be processed can be sterilized to a desired level. As a matter of course, in such a case, it is not necessary to repeat the processes from step S2 to step S7 a plurality of times.
[0039]
Thus, the processing from step S2 to step S7 is repeated a predetermined number of times. Then, after the ozone and active oxygen concentrations in the chamber 10 are sufficiently reduced, the object to be processed is taken out from the chamber 10 (S9). Thereby, the sterilization process is completed.
[0040]
Note that the processing procedure shown in FIG. 4 is an example, and the sterilization process can be performed by a simple processing procedure as follows. For example, in the processing procedure of FIG. 4, the sterilization process may be performed without using the second ultraviolet ray generation lamp 50. That is, in this case, active oxygen is generated using only the reaction shown in FIG. When only the first ultraviolet ray generation lamp 40 is turned on, the concentration of generated active oxygen is slightly lower than when both the first ultraviolet ray generation lamp 40 and the second ultraviolet ray generation lamp 50 are turned on. Still, sufficient active oxygen can be generated to perform the sterilization treatment.
[0041]
Further, for example, in the processing procedure of FIG. 4, the sterilization process may be performed without reducing the pressure inside the chamber 10 by the vacuum pump 70. When it is not necessary to diffuse active oxygen to all parts in the chamber 10 such as when it is desired to sterilize only the surface of the object to be treated, an effective sterilization treatment can be performed without reducing the pressure in the chamber 10. It can be carried out.
[0042]
Next, the present inventors conducted some experiments to confirm the effect of the sterilization treatment by the active oxygen sterilizer of the present embodiment by actually using microorganisms.
[0043]
First, the inventors conducted a first experiment for examining the ozone concentration in the chamber during the sterilization treatment for the active oxygen sterilizer of the present embodiment and the conventional active oxygen sterilizer. Specifically, in the first experiment, while measuring the time required for sterilization of the 6th bacterium, the ozone concentration in the chamber during the sterilization treatment was measured with an ozone monitor. Here, the time required for sterilization of the 6th power is 10 ⁶ This is the time it takes for the number of viable bacteria to be on the order of 1 after sterilization using an experimental sample of the order of.
[0044]
In this first experiment, Bacillus subtilis spores IFO16183 inoculated on the medium were used as samples. Moreover, in the active oxygen sterilizer of this embodiment and the conventional active oxygen sterilizer used in the first experiment, the space volume of the chamber is about 6 liters. The active oxygen sterilization apparatus of this embodiment is equipped with seven first ultraviolet ray generation lamps, and the conventional active oxygen sterilization apparatus is equipped with seven second ultraviolet ray generation lamps. Yes. Here, a synthetic quartz low-pressure mercury lamp (25 W) is used as the first ultraviolet generation lamp, and a low-pressure mercury lamp (= ozone) using titanium oxide-containing quartz glass in the arc tube as the second ultraviolet generation lamp. Reslump) (25 W) was used. Furthermore, in the active oxygen sterilizer of the present embodiment, an oxygen supply device that supplies oxygen is used, and the oxygen injection rate is set to 10 liters / min. On the other hand, in the conventional active oxygen sterilizer, ozone was supplied into the chamber by an ozonizer. The ozone injection rate was also set to 10 liters / min.
[0045]
In the first experiment using the active oxygen sterilization apparatus of the present embodiment, the sterilization process was performed according to the process procedure of FIG. 4 described above. However, the decompression process of step S2 was not performed. And the process from step S2 to step S7 was performed only once. Moreover, in the said apparatus, only the 1st ultraviolet-ray generation lamp was lighted and the 2nd ultraviolet-ray generation lamp was not lighted. That is, active oxygen was generated by the reaction of FIG. 3A, and the experimental sample was sterilized with the active oxygen.
[0046]
The result of this first experiment is shown in FIG. As shown in FIG. 5, in the experiment using the conventional active oxygen sterilizer, it took about 60 minutes to sterilize the 6th bacteria on the sample. And the ozone concentration in the chamber at the time of the said process was about 270 ppm. On the other hand, in the experiment using the active oxygen sterilizer of the present embodiment, it took about 60 minutes to sterilize the 6th bacteria on the sample. And the ozone concentration in the chamber at the time of the said process was about 150 ppm. Therefore, it is confirmed that the active oxygen sterilizer of this embodiment has almost the same sterilizing effect as compared with the conventional active oxygen sterilizer, but can reduce the concentration of ozone generated in the chamber by almost half. It was.
[0047]
In addition, the present inventors further conduct experiments related to the above first experiment, and when the active oxygen sterilizer of this embodiment is used, the sterilization effect increases as the number of the first ultraviolet ray generating lamps increases. Confirmed to improve.
[0048]
Next, the present inventors conducted a second experiment for examining how the bactericidal effect changes according to the number of times (number of turns) of repeating the processing from step S2 to step S7 in the processing procedure of FIG. went. In this second experiment, Bacillus subtilis spores IFO16183 inoculated on the medium were used as samples. Moreover, as the chamber 10 of the active oxygen sterilizer of this embodiment, a chamber having a space volume of about 60 liters was used. Three first ultraviolet ray generating lamps 40 are mounted in the chamber 10. As the first ultraviolet ray generation lamp 40, a 200 W W-tube synthetic quartz low-pressure mercury lamp was used. Further, as the oxygen supply device 30, an oxygen supply device was used, and the oxygen injection rate was set to 10 liters / min.
[0049]
In the second experiment, a first sample in which a sample is put in a bag, a second sample in which the sample is not put in a bag, and a bioindicator are prepared, and the processing procedure of FIG. 4 is performed for the first sample, the second sample, and the bioindicator. The sterilization treatment was performed according to And whenever the process from said step S2 to step S7 was complete | finished, the measurement of the number of viable bacteria and evaluation by the bioindicator were performed about the 1st sample and the 2nd sample. If a bioindicator is used, the presence or absence of bacteria inside the bioindicator can be determined by color. In the second experiment, the bioindicator is 2.4 × 10 6 in advance. ⁶ The one in which individual bacteria are inoculated is used. Therefore, if the bioindicator is negative, that is, no bacteria are present, the sterilization process at the sterilization level has been performed.
[0050]
Here, in the second experiment, the pressure in the chamber 10 was set to 1 kPa by the decompression process in step S2. In addition, oxygen was injected from the oxygen supply device 30 into the chamber 10 at a rate of 10 liters / min, and the oxygen injection was stopped after 5 minutes and 20 seconds had elapsed. At this time, the pressure in the chamber 10 is 94 kPa. Furthermore, the processing time for one time was set to 15 minutes. In this apparatus, the second ultraviolet ray generation lamp 50 was not turned on. That is, active oxygen was generated by the reaction shown in FIG. 3A, and the first and second samples were sterilized with the active oxygen.
[0051]
The result of this second experiment is shown in FIG. FIG. 6A shows the result of the second experiment as a graph, and FIG. 6B shows the result of the second experiment as a numerical value. In FIG. 6A, the vertical axis represents the Bacillus subtilis spore relative value (Log), and the horizontal axis represents the number of turns (times). Here, the vertical axis is represented on a logarithmic scale. Moreover, the points plotted with black squares in FIG. 6 (a) represent the viable cell count inside the bag, that is, the viable cell count of the first sample, and the points plotted with black circles represent the viable cell count outside the bag, It represents the viable count of the second sample.
[0052]
As shown in FIG. 6, the number of viable bacteria in the first sample was larger than the number of viable bacteria in the second sample regardless of the number of turns. This is because active oxygen is highly reactive, so that it reacts with the bag when it passes through the bag, and the concentration of active oxygen inside the bag is lower than the concentration of active oxygen outside the bag. It is believed that there is. However, since the viable count of the first sample also decreases each time the processing from step S2 to step S7 is repeatedly performed, the sterilization processing is also effectively performed for the first sample. This is because the active oxygen generated in the chamber 10 is rapidly diffused by supplying oxygen into the chamber 10 after the chamber 10 is depressurized, so that a large amount of active oxygen does not react with the bag. It is thought that this is because it can enter the inside of the bag.
[0053]
In addition, as shown in FIG. 6B, for the second sample, when the number of turns is 3, that is, when the process from step S2 to step S7 is performed three times, the evaluation by the bioindicator is negative for the first time. showed that. On the other hand, for the first sample, when the number of turns was 5, that is, when the processing from step S2 to step S7 was performed five times, the evaluation by the bioindicator was negative for the first time. Therefore, in the said apparatus, if the process from step S2 to step S7 is repeated 5 times or more, even if it is the sample put in the bag, it turns out that the process of a sterilization level can be performed.
[0054]
The present inventors conducted the second experiment by turning on the second ultraviolet ray generating lamp simultaneously with the first ultraviolet ray producing lamp. As a result, it was confirmed that the sterilization effect was further improved when both the first UV generating lamp and the second UV generating lamp were turned on, compared to when only the first UV generating lamp was turned on. .
[0055]
Next, the present inventors conducted a third experiment related to a process of decomposing residual ozone by the second ultraviolet ray generating lamp 50 after the sterilization process. In this third experiment, three 200 W low-pressure mercury lamps were used as the second ultraviolet generation lamp 50. In this third experiment, the ozone concentration in the chamber 10 is about 25 g / m. ³ Then, the second ultraviolet ray generation lamp 50 was turned on, and the ozone concentration in the chamber 10 thereafter was measured with an ozone monitor. The result of the third experiment is shown in FIG. In FIG. 7, the horizontal axis represents elapsed time (minutes), and the vertical axis represents ozone concentration (g / m ³ ). The second ultraviolet ray generating lamp 50 started to light when the elapsed time on the horizontal axis reached 30 minutes. As shown in FIG. 7, after the lighting of the second ultraviolet ray generation lamp 50, the ozone concentration rapidly decreased, and became less than the measurement lower limit value of the ozone monitor when 5 minutes and 30 seconds had elapsed from the start of lighting. Therefore, it was confirmed that even when the ozone concentration is high, it can be decomposed in a short time by turning on the second ultraviolet ray generation lamp 50 after the end of the sterilization treatment.
[0056]
In the active oxygen sterilizer of this embodiment, oxygen-containing gas is supplied from the oxygen supply device into the chamber, and ultraviolet rays are generated from the first ultraviolet ray generation lamp so that the oxygen is absorbed into the chamber. Compared to the conventional active oxygen sterilizer that generates active oxygen and sterilizes the object to be processed with the generated active oxygen, ozone concentration in the chamber during sterilization treatment compared to the conventional active oxygen sterilizer that supplies ozone into the chamber. Can be kept low. Therefore, the adverse effect of ozone on the human body during sterilization can be reduced.
[0057]
In addition, during the sterilization process, the second ultraviolet ray generation lamp is turned on together with the first ultraviolet ray generation lamp, thereby generating ozone generated by combining active oxygen and oxygen in the chamber from the second ultraviolet ray generation lamp. The absorbed ultraviolet rays are absorbed, and ozone can be decomposed into oxygen and active oxygen. For this reason, the concentration of active oxygen in the chamber can be increased, and the sterilization treatment can be performed on the object to be processed in a shorter time. Incidentally, after the sterilization treatment is completed, only the second ultraviolet ray generation lamp is turned on, so that the residual ozone in the chamber can be decomposed in a short time.
[0058]
In addition, by supplying a vacuum pump with a vacuum pump before supplying oxygen-containing gas from the oxygen supply device, the gas that has flowed into the chamber is rapidly diffused to all parts of the chamber. Can be made. Therefore, for example, when sterilizing a sample placed in a bag, the gas should be sufficiently introduced into the bag, or when sterilizing a cylindrical instrument, the gas should be spread to the inside of the instrument. Therefore, an effective sterilization process can be performed on such samples and instruments.
[0059]
Further, by supplying oxygen-containing gas from the oxygen supply device into the chamber and generating ultraviolet rays from the first ultraviolet ray generation lamp, the oxygen is absorbed by the oxygen to generate active oxygen in the chamber, and the generation By repeating the process of sterilizing the object to be processed for a predetermined processing time with the active oxygen thus generated, the sterilization level can be efficiently sterilized in a short time on the object to be processed.
[0060]
Furthermore, by providing a blower fan that stirs the gas contained in the chamber, for example, the gas can be circulated to the shaded area such as a lamp, so that the cover placed in the shaded area is covered. The treated product can also be sterilized effectively.
[0061]
In addition, this invention is not limited to said embodiment, A various deformation | transformation is possible within the range of the summary.
[0062]
In the above embodiment, the case where a low-pressure mercury lamp is used as an ultraviolet ray generation lamp has been described.In the present invention, in addition to such a low-pressure mercury lamp, for example, a discharge gas for forming excimer molecules is filled in a discharge vessel, A so-called excimer lamp using ultraviolet rays emitted from the excimer molecules may be used as the ultraviolet ray generation lamp.
[0063]
【The invention's effect】
As described above, according to the active oxygen sterilization apparatus according to the present invention, oxygen-containing gas is supplied into the processing chamber, and ultraviolet rays are generated from the first ultraviolet ray generation lamp, whereby the ultraviolet rays are supplied to the oxygen. Compared to the conventional active oxygen sterilizer that supplies ozone from the ozonizer or the like to the processing chamber by absorbing active gas to generate active oxygen in the processing chamber and sterilizing the object to be processed with the generated active oxygen During processing, the ozone concentration in the processing chamber can be kept low, and adverse effects of ozone on the human body can be reduced.
[0064]
In addition, during the sterilization process, the second ultraviolet ray generation lamp is turned on together with the first ultraviolet ray generation lamp, thereby generating ozone generated by combining active oxygen and oxygen in the treatment chamber from the second ultraviolet ray generation lamp. The absorbed ultraviolet rays are absorbed, and ozone can be decomposed into oxygen and active oxygen. For this reason, the density | concentration of the active oxygen in a process chamber can be made high, and a to-be-processed object can be sterilized in a shorter time.
[0065]
In addition, by reducing the pressure in the processing chamber by the decompression means before supplying the oxygen-containing gas from the oxygen supply means to the processing chamber, the gas flowing into the processing chamber is rapidly diffused to all parts of the processing chamber. Can be made. Therefore, for example, when sterilizing a sample placed in a bag, the gas should be sufficiently introduced into the bag, or when sterilizing a cylindrical instrument, the gas should be spread to the inside of the instrument. Therefore, an effective sterilization process can be performed on such samples and instruments.
[0066]
Further, a gas containing oxygen is supplied from the oxygen supply means into the processing chamber, and ultraviolet rays are generated from the first ultraviolet ray generation lamp so that the oxygen is absorbed into the processing chamber to generate active oxygen. By repeating the process of sterilizing the object to be processed for a predetermined processing time with the active oxygen thus generated, the sterilization level can be efficiently sterilized in a short time on the object to be processed.
[0067]
Further, by providing a stirring means for stirring the gas contained in the processing chamber, for example, the gas can be circulated to a shadowed portion such as a lamp, so that the cover placed in the shadowed portion is covered. The treated product can also be sterilized effectively.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of an active oxygen sterilizer according to an embodiment of the present invention.
FIG. 2 is a diagram for explaining light emission distribution of a low-pressure mercury lamp and absorption bands of oxygen and ozone.
FIG. 3 is a diagram for explaining the principle of generating active oxygen.
FIG. 4 is a flowchart for explaining a processing procedure for sterilizing an object to be processed in the active oxygen sterilizer according to the present embodiment.
FIG. 5 is a diagram showing the results of a first experiment.
FIG. 6 is a diagram showing the results of a second experiment.
FIG. 7 is a diagram showing the results of a third experiment.
[Explanation of symbols]
10 chambers
20 Oxygen supply device
30 Mass flow controller
40 First UV-generating lamp
50 Second UV lamp
60 blower fan
70 Vacuum pump
80 Ozone decomposition catalyst

Claims (3)

A processing chamber for storing an object to be processed;
Oxygen supply means for supplying a gas containing oxygen into the processing chamber;
Pressure reducing means for reducing the pressure in the processing chamber;
Stirring means for stirring the gas contained in the processing chamber;
A first ultraviolet ray generating lamp provided in the processing chamber for generating ultraviolet rays in a vacuum ultraviolet region;
A second ultraviolet light generating lamp that generates ultraviolet light in the far ultraviolet region, provided in the processing chamber;
With
After the object to be processed is accommodated in the processing chamber, the pressure in the processing chamber is reduced, the co the gas containing oxygen from the oxygen supply means is supplied into the processing chamber by said vacuum means, said first The ultraviolet ray generated by the ultraviolet ray generation lamp being turned on is absorbed by the oxygen and the sterilization treatment of the object to be processed is performed by the active oxygen generated in the treatment chamber, and the second ultraviolet ray generation lamp is ultraviolet ray generated by the lighting, the processing said that the active oxygen and the oxygen is absorbed in the ozone generated by combining in a chamber, the ozone is decomposed into oxygen and active oxygen,
Further, after a predetermined time before the inside of the processing chamber reaches atmospheric pressure has elapsed, the supply of the gas containing oxygen is stopped, and the gas in the processing chamber is stirred by the stirring means to sterilize the workpiece. An active oxygen sterilizer characterized in that a treatment is performed . After the elapse of a predetermined processing time, the first ultraviolet ray generation lamp is turned off , and after the predetermined time has elapsed, the second ultraviolet ray generation lamp is turned off , and then the object to be processed is taken out from the processing chamber. The active oxygen sterilizer according to claim 1.   3. The active oxygen sterilizer according to claim 2, wherein the process from reducing the pressure in the processing chamber by the decompression unit to the process of turning off the second ultraviolet ray generation lamp is repeated a predetermined number of times.

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