JPWO2016125810A1 - Sterilization apparatus and sterilization method - Google Patents

Abstract

A sterilization apparatus and a sterilization method for more efficient sterilization are provided. A sterilization apparatus according to the present invention includes a sterilization chamber that houses an object to be sterilized, a supply unit that supplies a sterilant containing hydrogen peroxide into the sterilization chamber, and a decompression unit that depressurizes the sterilization chamber. And a first decomposition unit for decomposing the hydrogen peroxide during the decompression. The first cracking unit includes a plurality of cracking catalyst units and switching means for switching the number of cracking catalyst units through which gas passes during the decompression. [Selection] Figure 4

Description

  The present invention relates to a sterilization apparatus and a sterilization method.

  Conventionally, various developments have been made on methods for sterilizing medical devices and the like. Examples of such a sterilization method include a method using ethylene oxide gas. However, the use of ethylene oxide gas is gradually increasing in the number of local governments that have regulations on emissions. Therefore, when this method is used, an expensive disassembling apparatus may be required.

  Therefore, in recent years, a sterilization method using hydrogen peroxide gas has attracted attention (see, for example, Patent Document 1). Hydrogen peroxide has self-decomposability, and the only gas generated after decomposition is water vapor and oxygen. Therefore, sterilization can be performed more safely than in the case of using ethylene oxide gas. In addition, hydrogen peroxide has a high sterilizing power and can be sterilized in a shorter time than other sterilization methods.

JP 2013-81560 A

  An object of this invention is to provide the sterilization apparatus and sterilization method for performing more efficient sterilization.

  According to the first aspect of the present invention, a sterilization chamber that houses an object to be sterilized, a supply unit that supplies a sterilant containing hydrogen peroxide into the sterilization chamber, a decompression unit that decompresses the sterilization chamber, A sterilization apparatus including a first decomposition unit for decomposing the hydrogen peroxide during decompression, wherein the first decomposition unit includes a plurality of decomposition catalyst units and the number of the decomposition catalyst units through which gas passes during the decompression. There is provided a sterilization device comprising switching means for switching between the two.

  According to the second aspect of the present invention, the step of containing an object to be sterilized in a sterilization chamber, the first depressurization step of depressurizing the sterilization chamber, and hydrogen peroxide is contained in the sterilization chamber after the first depressurization step. A sterilization method including a supply step of supplying a sterilizing agent and a second pressure reduction step of reducing the pressure in the sterilization chamber after the supply step, wherein the cracking catalyst unit has a smaller number of gases in the first pressure reduction step. And a sterilization method configured to pass a larger number of cracking catalyst units in the second decompression step.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide the sterilization apparatus and sterilization method for performing more efficient sterilization.

FIG. 1 is a flowchart illustrating an example of the flow of a sterilization method according to an aspect of the present invention. FIG. 2 is a flowchart illustrating an example of the flow of a sterilization method according to an aspect of the present invention. FIG. 3 is a flowchart illustrating an example of the flow of a sterilization method according to an aspect of the present invention. FIG. 4 is a conceptual diagram illustrating an overall configuration of a sterilization apparatus according to an aspect of the present invention. FIG. 5 shows a plurality of holes provided in the supply unit of the sterilizer according to one aspect of the present invention. FIG. 6 is a conceptual diagram illustrating a hydrogen peroxide supply step of the sterilization method according to an aspect of the present invention. FIG. 7 is a perspective view showing an example of an evaporating dish constituting the evaporating unit of the sterilizing apparatus according to one aspect of the present invention. FIG. 8 is a schematic diagram illustrating an example of installation of the sensor SNS. FIG. 9 is a schematic diagram illustrating an example of installation of the sensor SNS. FIG. 10 is a schematic diagram illustrating an example of the configuration of the sensor SNS. FIG. 11 is a graph showing the relationship between the sterilization time and the number of surviving bacteria.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In each figure, the same reference numerals are given to components that exhibit the same or similar functions, and duplicate descriptions are omitted.

  1 to 3 are flowcharts illustrating an example of a flow of a sterilization method according to one embodiment of the present invention. Hereinafter, although the sterilization method and sterilization apparatus which concern on 1 aspect of this invention are demonstrated along this flow chat, the scope of the present invention is not limited to these.

  FIG. 4 is a conceptual diagram illustrating an overall configuration of a sterilization apparatus according to an aspect of the present invention. 4 includes a sterilization chamber 20, a supply unit 30, an evaporation unit 40, a concentration measuring unit 45, a filling unit 50, a decompression unit 60, a first decomposition unit 70, and a second decomposition. A unit 71, a residual liquid recovery unit 80, a dehumidifying unit 90, and a filter 91 are provided. The evaporation unit 40, the concentration measuring unit 45, the filling unit 50, the decompression unit 60, the second decomposition unit 71, the residual liquid recovery unit 80, the dehumidifying unit 90, and the filter 91 may be omitted. In addition, specific configurations such as a pressure gauge, a valve, a vacuum gauge, a pump, and a sensor, which will be described later, are merely examples, and the scope of the present invention is not limited thereto.

  The sterilization chamber 20 is configured to accommodate an object to be sterilized. The sterilization chamber 20 is typically a vacuum chamber. The sterilization chamber 20 includes a pressure gauge PG1. The sterilization chamber 20 is connected to the outside of the system through a solenoid valve SV14 and a filter 91. The sterilization chamber 20 includes a door (not shown). This door may be provided with an arbitrary safety mechanism.

  The supply unit 30 is connected to the sterilization chamber 20 via three-way solenoid valves SV7 and SV8. The supply unit 30 is configured to supply a sterilant containing hydrogen peroxide into the sterilization chamber 20. The hydrogen peroxide may be hydrogen peroxide gas or liquid hydrogen peroxide. The supply unit 30 includes a pressure gauge PG2. The supply unit 30 is connected to the outside of the system through a solenoid valve SV6 and a filter 91. The supply unit 30 may include a heater.

  The supply unit 30 includes a member 31 having a plurality of holes. The configuration and function of the member 31 will be described in detail later. The member 31 may be omitted.

  The sterilization chamber 20 and the supply unit 30 are connected to a vacuum gauge CG1 via a three-way solenoid valve SV11. The vacuum gauge CG1 is used to measure the absolute pressure of the sterilization chamber 20 and / or the supply unit 30. The vacuum gauge CG1 is also used for indirect concentration management in the supply unit 30 when, for example, the supply unit 30 concentrates the sterilant by referring to the saturated vapor pressure curve of hydrogen peroxide. Can do.

  The evaporation unit 40 is provided, for example, inside the sterilization chamber 20. For example, the evaporation unit 40 is configured to evaporate the liquid hydrogen peroxide supplied from the supply unit 30 in the sterilization chamber 20. As a result, the sterilization chamber 20 is filled with hydrogen peroxide gas, and the object to be sterilized can be sterilized. The evaporation unit 40 is preferably installed near the center of the sterilization chamber 20. This makes it possible to more efficiently diffuse the hydrogen peroxide gas in the sterilization chamber 20. Note that the evaporation unit 40 may be provided outside the sterilization chamber 20.

  The evaporator 40 typically includes an evaporating dish that receives liquid hydrogen peroxide and a heater that heats the evaporating dish. As this evaporating dish, a flat thing, a crucible shape, or a cylindrical thing is mentioned, for example. These configurations and functions will be described in detail later.

  The sterilizer 10 may include a concentration measuring unit 45 in the sterilization chamber 20. This concentration measuring means 45 is used for measuring the concentration of hydrogen peroxide gas in the sterilization chamber 20. The sterilizer 10 may further include a control unit (not shown) that adjusts the amount of sterilant supplied to the sterilization chamber 20 in accordance with the hydrogen peroxide gas concentration measured by the concentration measuring means 45. .

  The density measuring means 45 typically includes a light source 45A and a photometer 45B. The concentration measuring means 45 typically further includes a measuring unit (probe) 45C. The light source can be freely selected as long as it contains ultraviolet light having a wavelength of 300 nm or less and / or infrared light having a wavelength of 1400 nm or more, which is absorbed by hydrogen peroxide, but preferably a monochromatic light source such as a light emitting diode is used. A monochromatic light source can be used. In this case, it is not necessary to perform wavelength selection using a prism, an optical filter, or the like, so that the apparatus can be reduced in size and cost. In this case, the amount of light is increased and the measurement accuracy is improved. As the photometer, for example, a photodiode can be used.

  The filling unit 50 is configured to fill the supply unit 30 with a sterilant. The filling unit 50 is connected to the supply unit 30 via a liquid feed pump TP and a solenoid valve SV5. A sensor SNS and a pressure gauge PG3 are connected to the piping connecting the filling unit 50 and the supply unit 30. For example, the pressure gauge PG3 functions as a safety device that forcibly stops the liquid feeding pump when the pressure in the pipe rises due to a device abnormality.

  The filling unit 50 typically includes a cartridge containing a sterilant. The filling unit 50 is configured to suck up the sterilizing agent from the cartridge using an extraction tube, for example, and fill the supply unit 30 with the sterilizing agent.

  The decompression unit 60 is configured to decompress the interior of the sterilization chamber 20 and / or the supply unit 30. The decompression unit 60 is connected to the first disassembly unit 70 via the solenoid valve SV0. The decompression unit 60 is connected to the second disassembly unit 71 through solenoid valves SV0 and SV4. The decompression unit 60 is connected to the outside of the system through a solenoid valve SV1.

  The decompression unit 60 includes a rotary pump RP and an oil mist separator Sep. The oil mist separator Sep is connected to the discharge side of the rotary pump RP and is configured to collect oil mist generated from the rotary pump RP. The oil mist separator Sep is connected to the suction side of the rotary pump RP via a solenoid valve SV16. Thereby, the oil collected by the oil mist separator Sep can be collected by the rotary pump RP. Note that the oil mist separator Sep may be omitted. Moreover, other vacuum pumps, such as a dry pump, can also be used instead of rotary pump RP.

  The first decomposition unit 70 is provided between the sterilization chamber 20 and the decompression unit 60. The first decomposition unit 70 includes, for example, a first decomposition catalyst unit 70A and a second decomposition catalyst unit 70B. These decomposition catalyst units are configured to decompose hydrogen peroxide. The first cracking catalyst unit 70A and the second cracking catalyst unit 70B are connected in series. The first disassembly unit 70 is connected to the sterilization chamber 20 via solenoid valves SV2 and SV3 arranged in parallel with each other. The first decomposition unit 70 is configured such that when the solenoid valve SV2 is opened, the gas passes only through the first decomposition catalyst unit 70A. Further, the first decomposition unit 70 is configured such that when the solenoid valve SV3 is opened, the gas passes through both the first decomposition catalyst unit 70A and the second decomposition catalyst unit 70B. The configuration and function of the first disassembly unit 70 will be described in detail later. In the above description, the example in which the first cracking unit 70 includes two cracking catalyst units has been described. However, the first cracking unit 70 may include three or more cracking catalyst units.

  The second disassembly unit 71 is connected to the supply unit 30 via a solenoid valve SV9. The second decomposition unit 71 includes a decomposition catalyst unit configured to decompose hydrogen peroxide. The second decomposition unit 71 is used in a concentration step and a residual liquid recovery step described later. The configuration and function of the second disassembly unit 71 will be described in detail later. Further, as will be described later, the solenoid valve SV4 may be connected to the first disassembly unit 70 without providing the second disassembly unit 71.

  In the present specification, the “decomposition unit” and the “decomposition catalyst unit” are not limited to those capable of detoxifying hydrogen peroxide, and include not only those that decompose hydrogen peroxide and those that catalyze the decomposition reaction. Also included are those that adsorb and remove hydrogen peroxide.

  The residual liquid recovery unit 80 is configured to recover the sterilant remaining in the supply unit 30. The residual liquid recovery unit 80 typically includes a heater for vaporizing the recovered sterilant. The hydrogen peroxide vaporized in the residual liquid recovery unit 80 passes through the second decomposition unit 71 and is discharged out of the system. The configuration and function of the residual liquid recovery unit 80 will be described in detail later.

The dehumidifying unit 90 is configured to dehumidify air flowing into the system. The dehumidifying unit 90 is connected to the sterilization chamber 20 via a solenoid valve SV12. The dehumidifying unit 90 is connected to the sterilization chamber 20, the supply unit 30, and the residual liquid recovery unit 80 via the solenoid valve SV10. The dehumidifying unit 90 is connected to the outside of the system through a solenoid valve SV13 and a filter 91. Further, the dehumidifying unit 90 is connected to the outside of the system through a solenoid valve SV15. The configuration and function of the dehumidifying unit 90 will be described in detail later.
The filter 91 is used for cleaning air flowing into the system. As the filter 91, for example, a HEPA filter can be used.

  In the sterilization method illustrated in FIGS. 1 to 3, first, the supply unit 30 is decompressed. This decompression step corresponds to step 100 in FIG.

  In this return pressure process, the solenoid valve SV6 is opened, and air flows into the supply unit 30 from outside the system via the filter 91. Thereby, supply unit 30 is returned to atmospheric pressure among sterilizers 10.

Next, the sterilizing agent is filled. This filling step corresponds to step 110 in FIG.
In this filling step, a sterilizing agent containing hydrogen peroxide is filled from the filling unit 50 to the supply unit 30. This step can be performed, for example, as follows. First, in a state where the tip of the extraction tube in the filling unit 50 is positioned below the liquid level of the sterilizing agent in the cartridge, the solenoid valve SV5 is opened and the liquid feed pump TP is operated. When the sensor SNS detects the required amount of suction, the liquid feeding pump TP is stopped. The extraction tube is moved above the liquid level of the sterilizing agent, and the liquid feeding pump TP is operated again. Thereby, a necessary amount of the sterilizing agent is filled from the filling unit 50 into the supply unit 30.

In this filling step, the sensor SNS functions to detect that a fixed amount (for example, 3 ml) has been sucked out. Specifically, the sensor SNS is turned on when a fixed amount of suction is completed. Further, after the completion of the sucking, when the same amount of liquid feeding is completed, the state is turned off. At this time, the time from the start of suction until the sensor SNS is turned on is compared with the time from when the sensor SNS is turned on until the sensor SNS is turned off, and if both are not equal, a warning is issued. It can also be. In this way, it is possible to more reliably detect that the entire amount of the sterilizing agent sucked out has been supplied to the supply unit 30.
In parallel with the filling step, the first pressure reduction is performed. This first decompression step corresponds to step 120 in FIG.

  In the first decompression step, the inside of the sterilization chamber 20 is decompressed. This decompression can be performed, for example, as follows. First, the solenoid valve SV11 is opened. Then, the solenoid valve SV2 is opened while the solenoid valve SV3 is closed. The rotary pump RP is activated, and in conjunction with this, the solenoid valve SV0 is opened and the solenoid valve SV1 is closed. Thereby, the inside of the sterilization chamber 20 can be decompressed.

  As described above, the first decompression step is performed with the solenoid valve SV2 opened while the solenoid valve SV3 is closed. Thereby, the gas passes only through the first cracking catalyst unit 70A and does not pass through the second cracking catalyst unit 70B. By adopting such a configuration, it becomes possible to efficiently reduce the pressure in the sterilization chamber 20 in a shorter time than when all the decomposition catalyst units are passed.

Thereafter, the temperature of the object to be sterilized is adjusted. This temperature adjustment step corresponds to step 130 in FIG.
In this temperature adjustment step, air from outside the system is introduced into the sterilization chamber 20 to increase the temperature of the object to be sterilized disposed in the sterilization chamber 20. This step can be performed, for example, as follows. First, the solenoid valves SV13 and SV12 are opened, and a small amount of air is introduced into the sterilization chamber 20 from outside the system. Due to the kinetic energy of the introduced air, the temperature of the object to be sterilized disposed in the sterilization chamber 20 that has decreased in the first decompression step can be increased. Note that air introduced into the sterilization chamber 20 is purified by the filter 91 and dehumidified by the dehumidifying unit 90.

  Note that the inlet for introducing air into the sterilization chamber 20 in the temperature adjustment step is preferably provided in the vicinity of the evaporation unit 40, for example, in the vicinity of the center of the sterilization chamber 20. If it carries out like this, it will become possible to warm more efficiently the to-be-sterilized thing in the sterilization chamber 20 by introduction | transduction of air by warming the air in the evaporation part 40. FIG.

  Further, a nozzle that causes an air flow in a direction opposite to a direction toward the connection port with the first decomposition unit 70 may be further provided at the inlet of the sterilization chamber 20. In this way, the introduced air can be circulated through the sterilization chamber 20 and then sucked toward the first decomposition unit 70. Therefore, by adopting such a configuration, the temperature can be adjusted more efficiently.

  In addition, you may implement | achieve the temperature rise in the sterilization chamber 20 in a temperature adjustment process by another method. For example, this temperature adjustment may be performed by heating an object to be sterilized in the sterilization chamber 20 using a heating means such as an infrared heater. However, using a method of adjusting the temperature by introducing air is more efficient because the sterilization chamber 20 can be heated from the inside. Note that the temperature adjustment step may be omitted, and the product to be sterilized in the sterilization chamber 20 may be naturally warmed by heat transfer or radiant heat from the sterilization chamber 20. However, if the temperature adjustment process is positively performed, the time required for the entire sterilization operation can be shortened. Moreover, the efficiency of heating can be further increased by installing a heater in the middle of the path for injecting air and heating the inflowing air.

  In the flowchart shown in FIG. 1, the filling step 110, the first decompression step 120, and the temperature adjustment step 130 are performed in parallel, but the filling step 110, the first decompression step 120, and the temperature adjustment step 130 are performed. It is also possible to perform them in series instead of in parallel. However, if the filling step 110, the first decompression step 120, and the temperature adjustment step 130 are performed in parallel, the time required for the entire sterilization operation can be shortened.

  As shown in FIG. 1, in the sterilization method, after the filling step 110 is completed, it is determined whether or not it is necessary to concentrate the sterilizing agent. If the sterilant needs to be concentrated, the process proceeds to Steps 140 and 150. If the sterilant is not required to be concentrated, the process 140 is omitted and the process proceeds to Step 150. The determination of the necessity of concentration of the sterilizing agent is performed according to, for example, the type of the sterilized material. For example, in the case of sterilizing only the surface of a sterilized product having no lumen (surface sterilization), sterilization is typically performed using a concentrated sterilizing agent. On the other hand, in the case of sterilization to the inside of a sterilized product having a lumen (lumen sterilization), it is determined whether or not concentration is performed according to the specific needs of the user. Note that the concentration may be always performed without determining whether the concentration is necessary, or the concentration may not always be performed.

Subsequently, if necessary, concentration is performed. This concentration step corresponds to step 140 in FIG.
In this concentration step, the sterilizing agent filled in the supply unit 30 is concentrated as necessary. This concentration process can be performed as follows, for example. That is, the solenoid valve SV11 is closed and SV4 and SV9 are opened. Thereby, the supply unit 30 is depressurized, and the sterilizing agent in the supply unit 30 can be concentrated to an appropriate concentration by continuing the depressurization in the supply unit 30 to an appropriate pressure according to the saturated vapor pressure curve of hydrogen peroxide. It becomes possible.

  The supply unit 30 is typically configured such that the sterilizing agent in the supply unit 30 is concentrated by the decompression unit 60. By using the decompression unit 60 at the time of concentration, it becomes possible to concentrate the sterilizing agent at a lower temperature than in the case where the decompression unit 60 is not used.

  The supply unit 30 is desirably temperature-adjusted to a temperature at which the concentration of the sterilant can be ignored under atmospheric pressure. Thereby, the concentration of the sterilizing agent can be started only after the supply unit 30 is decompressed. The temperature of the supply unit 30 is, for example, preferably 70 ° C. or less, more preferably in the range of 30 ° C. to 70 ° C., and still more preferably in the range of 40 ° C. to 60 ° C. By performing concentration under reduced pressure, the time required for concentration can be shortened. Moreover, since concentration can be performed at a relatively low temperature, unintended decomposition of the sterilant due to heating can be suppressed. The temperature adjustment of the supply unit 30 can be performed using, for example, the heater described above.

  As described above, the supply unit 30 includes the member 31 having a plurality of holes. This member 31 is provided in the supply unit 30 and above the liquid level of the filled sterilant. By adopting such a configuration, in the concentration step, it is possible to suck the vapor from the sterilant and suppress the suction of the boiled liquid. That is, by adopting such a configuration, loss of hydrogen peroxide in the concentration step can be reduced.

  FIG. 5 is a perspective view illustrating an example of a member having a plurality of holes provided in the supply unit of the sterilizer according to one aspect of the present invention. The member 31 includes a plurality of holes 31H. By adopting such a configuration, the above-described effects can be achieved. In addition, in FIG. 5, although the aspect which provided the four holes 31H is drawn, the two or more holes 31H should just be provided. Moreover, in this member 31, you may make crucible shape the upper part of the some hole 31H. If it carries out like this, it will become possible to return the liquid which has passed the some hole 31H to the supply unit 30 again after a concentration process.

  A mesh member may be used as the member 31 having a plurality of holes. Even when such a configuration is adopted, at least a part of the hydrogen peroxide scattered in the concentration step is captured by the mesh member and can be recovered in the supply unit 30. That is, by adopting such a configuration, the loss of hydrogen peroxide in the concentration step can be reduced.

  A sintered filter may be used as the member 31 having a plurality of holes. Even when such a configuration is employed, at least a part of the hydrogen peroxide scattered in the concentration step is captured by the sintered filter and can be recovered in the supply unit 30. That is, by adopting such a configuration, the loss of hydrogen peroxide in the concentration step can be reduced.

  The diameter of the hole 31H is, for example, 10 mm or less, preferably in the range of 0.001 to 10 mm, more preferably in the range of 0.1 to 5 mm, and still more preferably in the range of 0.5 to 1.5 mm. To do. In addition, two or more members 31 can be used in an overlapping manner. In this case, the positions of the holes 31H of the plurality of members 31 may be shifted from each other.

  In the concentration step, the recovered gas passes through the second decomposition unit 71. Thereby, compared with the case where the gas collect | recovered in the concentration process passes the 1st decomposition | disassembly unit 70, generation | occurrence | production of the dew condensation by the moisture in the said gas in the 1st decomposition | disassembly unit 70 can be decreased. That is, this makes it possible to shorten the time required to re-evaporate the condensation in the first decomposition unit 70. Thus, this makes it possible to shorten the entire sterilization operation.

  Next, a second pressure reduction is performed. This second decompression step corresponds to step 150 in FIG. This 2nd pressure reduction process can be performed by the method similar to the 1st pressure reduction process mentioned above, for example.

   Thereafter, holding is performed before supply. This pre-supply holding step corresponds to step 160 in FIG. In this holding step, the solenoid valve SV2 is closed and held for a short time.

  Next, as shown in FIG. 2, steps 170, 180, and 190 described later are repeated until a predetermined time elapses. As a result, a sufficient amount of hydrogen peroxide gas is allowed to reach the sterilization chamber 20.

FIG. 6 is a conceptual diagram illustrating a hydrogen peroxide supply step of the sterilization method according to an aspect of the present invention. This hydrogen peroxide supply step corresponds to step 170 in FIG.
In the hydrogen peroxide supply step shown in FIG. 6, a sterilant containing liquid hydrogen peroxide is supplied from the supply unit 30 into the sterilization chamber 20. The liquid hydrogen peroxide supplied from the supply unit 30 into the sterilization chamber 20 is configured to be vaporized in the evaporation unit 40. The evaporation unit 40 typically includes an evaporating dish 41 that receives liquid hydrogen peroxide and a heater that heats the evaporating dish 41. This step can be realized, for example, by opening the three-way solenoid valves SV7 and SV8 for a certain time. Note that this step may be performed by supplying a sterilant containing hydrogen peroxide gas into the sterilization chamber 20.

  As described above, the evaporation unit 40 may be provided in the sterilization chamber 20. In this case, the liquid hydrogen peroxide supplied from the supply unit 30 is instantly vaporized in the sterilization chamber 20 and diffused into the sterilization chamber 20. By adopting such a configuration, further efficient and safe sterilization becomes possible.

  FIG. 7 is a perspective view showing an example of an evaporating dish constituting the evaporating unit of the sterilizing apparatus according to one aspect of the present invention. The evaporating dish 41 shown in FIG. 7 includes a plurality of radial grooves G1 and a plurality of circumferential grooves G2. As described above, the surface area of the evaporating dish 41 is increased by providing the evaporating dish 41 with at least one concave portion and / or convex portion. Therefore, by providing the evaporating dish 41 with at least one recess and / or protrusion, it is possible to more efficiently vaporize the liquid hydrogen peroxide supplied from the supply unit 30. In particular, when the evaporating dish 41 is provided with at least one circumferential groove, the sterilizing agent can be prevented from falling off from the evaporating dish 41, so that the sterilizing agent can be evaporated on the evaporating dish 41 more efficiently. . Further, when at least one radial groove is provided in the evaporating dish 41, the evaporation speed is increased due to the expansion of the liquid level on the evaporating dish 41, and the sterilizing agent is evaporated more efficiently on the evaporating dish 41. Can do. When the evaporating dish 41 is provided with at least one circumferential groove and at least one groove intersecting the evaporating dish 41, the sterilizing agent is evaporated more efficiently on the evaporating dish 41 by a combination of the above effects. be able to.

  In the sterilization method illustrated in FIGS. 1 to 3, subsequently, slight recovery pressure is performed. This slight pressure-reducing step corresponds to step 180 in FIG. In this slight recovery pressure step, a small amount of air is caused to flow from outside the system into the sterilization chamber 20 via the sterilant supply path. This can be realized, for example, by closing the three-way solenoid valve SV8 and opening the solenoid valve SV10. Thereby, hydrogen peroxide remaining in a trace amount in the path can be pushed out to the evaporation section.

  Next, holding after supply is performed. This post-supply holding step corresponds to step 190 in FIG. In this step, the above-described slight recovery pressure is stopped and the state in the sterilization chamber 20 is maintained for a certain period of time. Thereby, the pressure in the sterilization chamber 20 is stabilized.

  After the above steps, if the predetermined time has not elapsed and the hydrogen peroxide concentration in the sterilization chamber 20 has not reached the predetermined concentration, steps 170 to 190 are repeated. The hydrogen peroxide concentration in the sterilization chamber 20 can be measured by, for example, the concentration measuring means 45 as described above. Here, the number of times of supplying the sterilizing agent is controlled depending on whether the hydrogen peroxide concentration in the sterilization chamber 20 has reached a predetermined concentration, but this control sets the number of times of supplying the sterilizing agent to the predetermined number of times. It can also be done by defining. This number of times may be, for example, once or twice or more.

After the predetermined time has elapsed, as shown in the upper part of FIG. Until the predetermined number of times, after the steps 200 and 210, the process described in the lower part of FIG. 1 is repeated. After reaching the predetermined number of times, the process proceeds to step 220. The predetermined number of times is not particularly limited. However, when performing sterilization guarantee based on the half cycle method, it is necessary to be an even number of times.
If the predetermined number of times described above has not been reached, the hydrogen peroxide gas is diffused and the sterilant is refilled. This diffusion and filling process corresponds to the process 200 in FIG.
In this diffusion and filling process, the diffusion of the hydrogen peroxide gas in the sterilization chamber 20 and the filling of the sterilizing agent into the filling unit 50 are performed simultaneously.

  The diffusion of the hydrogen peroxide gas in the sterilization chamber 20 is performed, for example, by flowing air into the sterilization chamber 20 from outside the system and generating an air flow in the sterilization chamber 20. This diffusion can be realized, for example, by opening the solenoid valves SV12 and SV13.

  The filling of the sterilizing agent into the filling unit 50 can be performed, for example, by the same method as described above. Thus, by simultaneously diffusing the hydrogen peroxide gas and filling the sterilizing agent, it is possible to reduce the time required for the process and thus the time required for the entire sterilization operation. Note that the hydrogen peroxide gas diffusion and the sterilizing agent filling may be performed in series.

Next, hydrogen peroxide is removed. This hydrogen peroxide removal step corresponds to step 210 in FIG.
In this hydrogen peroxide removal step, the hydrogen peroxide gas in the sterilization chamber 20 is removed. This process is performed as follows, for example. That is, the solenoid valves SV12 and SV13 are closed and the solenoid valve SV3 is opened. Thereby, the inside of the sterilization chamber 20 is depressurized, and the gas in the sterilization chamber 20 passes through the second decomposition catalyst unit 70B and the first decomposition catalyst unit 70A and is discharged out of the system.

  Thus, in the hydrogen peroxide removal step, the gas in the sterilization chamber 20 passes through the two decomposition catalyst units. Thereby, hydrogen peroxide in the gas in the sterilization chamber 20 can be more reliably removed. On the other hand, as described above, in the first and second decompression steps, the gas in the sterilization chamber 20 passes through only one decomposition catalyst unit. By adopting such a configuration, the time required for the entire sterilization can be further shortened, and the hydrogen peroxide gas can be more reliably removed.

  In the above-described configuration, one cracking catalyst unit is used in the first and second decompression steps, and two cracking catalyst units are used in the hydrogen peroxide removal step. However, in the first and second decompression steps, The same effect can be achieved if the number of cracking catalyst units used is smaller than the number of cracking catalyst units used in the hydrogen peroxide removal step. That is, when decompressing by the decompression unit 60 before supplying hydrogen peroxide into the sterilization chamber 20, the gas passes through a smaller number of decomposition catalyst units, and after supplying hydrogen peroxide into the sterilization chamber 20. When the pressure is reduced by the pressure reducing unit 60, the gas may pass through a larger number of cracking catalyst units. Alternatively, when the pressure is reduced by the pressure reducing unit 60 before hydrogen peroxide is supplied into the sterilization chamber 20, only a part of the plurality of decomposition catalyst units may pass through the gas. For example, one decomposition catalyst unit may be used in the first and second decompression steps, and two or more decomposition catalyst units may be used in the hydrogen peroxide removal step. Alternatively, the first and second decompression steps may employ a configuration in which the exhausted gas does not use the cracking catalyst unit. More specifically, in a situation where hydrogen peroxide is not present in the sterilization chamber 20 (first decompression step and / or second decompression step), no decomposition catalyst unit is used and hydrogen peroxide is present in the sterilization chamber 20. In this situation (step 240 described below), decompression may be performed using a cracking catalyst unit.

  When the above-mentioned predetermined number of times is reached, hydrogen peroxide gas is diffused. This diffusion step corresponds to step 220 in FIG. This diffusion step can be performed, for example, in the same manner as the former in the diffusion and filling step described above.

Thereafter, as shown in FIG. 3, the hydrogen peroxide gas is removed. This step 230 can be performed, for example, by the same method as described above.
Subsequently, as shown in FIG. 3, the sterilization chamber 20 is depressurized. This step 240 can be performed, for example, by the same method as described above.

  Next, the decompression and decompression of the sterilization chamber 20 are repeated a predetermined number of times as necessary. In the restoring pressure process 250, the sterilization chamber 20 is decompressed. This return pressure can be performed, for example, by opening the solenoid valve SV14. There is no particular limitation on the predetermined number of times. For example, the decompression process 250 may be performed only once, may be performed twice or more, and may not be performed at all. Further, this repetition may be controlled not by the number of times but by time.

Next, final pressure recovery and residual liquid recovery are performed. This final return pressure and residual liquid recovery step corresponds to step 260 in FIG.
In this final return pressure and residual liquid recovery step, the return pressure in the sterilization chamber 20 and the recovery of the sterilant remaining in the supply unit 30 are performed simultaneously. The former can be performed, for example, by the same method as described above. The latter can be performed, for example, by opening the solenoid valve SV4 and the three-way solenoid valve SV8 and transferring the residual liquid in the supply unit 30 to the residual liquid recovery unit 80. This residual liquid is vaporized in the residual liquid recovery unit 80, and the vaporized hydrogen peroxide is decomposed in the second decomposition unit 71. The residual liquid recovery unit 80 and the second decomposition unit 71 may be integrated. Employing such a configuration makes it possible to recover the remaining liquid and decompose hydrogen peroxide more efficiently. Although the residual liquid recovery unit 80 is connected to the second decomposition unit 71 in the above, the residual liquid recovery unit 80 can be connected to the first decomposition unit 70 and used. Further, the final return pressure and the residual liquid recovery may be performed as separate steps.

  Next, the remaining liquid is further collected. This residual liquid recovery step corresponds to step 270 in FIG. In this step, residual liquid remaining on the wall surface of the supply unit 30 is further removed by evaporating to a harmless level, and decomposition of hydrogen peroxide in the second decomposition unit 71 is continued. This step can be realized, for example, by closing the three-way solenoid valve SV8 and opening the solenoid valve SV9. The subsequent steps can be performed completely independently from the sterilization chamber 20. That is, the user can freely take out the article to be sterilized at this point. ”

  Next, drainage of the dehumidifying unit and oil recovery are performed. This step corresponds to step 280 in FIG. In this step, drainage of the dehumidifying unit 90 and oil recovery from the rotary pump RP are performed simultaneously. These two steps may be performed in series.

  The drainage of the dehumidifying unit 90 is performed as follows, for example. That is, drainage from the dehumidifying unit 90 is performed by opening the solenoid valves SV13 and SV15. Thereby, it becomes possible to use the dehumidification unit 90 over a long period of time.

  The oil is collected, for example, as follows. That is, first, the solenoid valve SV16 is opened. Thereafter, the rotary pump RP is stopped, and in conjunction therewith, the solenoid valve SV0 is closed and the solenoid valve SV1 is opened. Thereby, oil is collect | recovered by rotary pump RP from separator Sep. That is, this makes it possible to use the rotary pump RP for a longer period of time.

  Thus, the sterilization of the article to be sterilized is completed. However, the configuration described with reference to FIGS. 1 to 7 is merely an example. A sterilization apparatus according to the present invention includes a sterilization chamber that houses an object to be sterilized, a supply unit that supplies a sterilizing agent containing hydrogen peroxide into the sterilization chamber, a decompression unit that decompresses the sterilization chamber, A sterilization apparatus including a first decomposition unit for decomposing hydrogen peroxide, wherein the first decomposition unit switches a plurality of decomposition catalyst units and the number of the decomposition catalyst units through which gas passes during the decompression. And other switching elements may be omitted. The sterilization method according to the present invention includes a step of storing an object to be sterilized in a sterilization chamber, a first depressurization step of depressurizing the sterilization chamber, and hydrogen peroxide in the sterilization chamber after the first depressurization step. A sterilization method including a supply step of supplying a sterilizing agent and a second pressure reduction step of reducing the pressure in the sterilization chamber after the supply step, wherein the cracking catalyst unit has a smaller number of gases in the first pressure reduction step. In the second decompression step, the gas may pass through a larger number of cracking catalyst units, and the other steps may be omitted.

  In the sterilization apparatus and sterilization method described above, the supply unit 30, the sterilization chamber 20, the first decomposition unit 70, and the optional second decomposition unit 71 and residual liquid recovery unit 80 are always subjected to negative pressure or large pressure. It is configured to be at atmospheric pressure. That is, these components are configured such that the pressure does not exceed atmospheric pressure. By adopting such a configuration, even if a problem occurs in the piping system or the like, it is possible to prevent the gas from leaking to the outside.

  Next, the diffusion step and the return pressure step 250 allow air to flow into the sterilization chamber 20 from outside the system. Here, the air inflow speed in both steps will be described. The inflow speed in the diffusion process is controlled to be smaller than the inflow speed in the return pressure process 250. This control is realized, for example, by making the opening area when the solenoid valve SV12 is opened smaller than the solenoid valve SV14. Thereby, the hydrogen peroxide gas that is difficult to diffuse in the diffusion step can be diffused into the lumen of the object to be sterilized. On the other hand, in the decompression step 250, the hydrogen peroxide in the sterilization chamber 20 can be removed in a short time.

  In the above embodiment, an example in which one sensor SNS is provided has been described, but the present invention is not limited to this. FIG. 8 is a schematic diagram illustrating an example of installation of the sensor SNS. As shown in FIG. 8, the sterilization apparatus may include a plurality (for example, two) of sensors SNS. Sensor SNS-1 and sensor SNS-2 are installed at a distance. Specifically, the sensor SNS-1 is provided at a position where the volume in the pipe from the tip of the extraction pipe to the sensor SNS-1 becomes a first predetermined amount (for example, 3.4 ml). The sensor SNS-2 is provided at a position where the volume in the pipe from the sensor SNS-1 to the sensor SNS-2 becomes a second predetermined amount (for example, 3.3 ml) smaller than the first predetermined amount.

  The filling process of the sterilizing agent from the filling unit 50 to the supply unit 30 in this configuration is performed as follows. First, with the extraction tube inserted into the cartridge 1052 and the tip of the extraction tube positioned below the sterilant liquid level, the solenoid valve SV5 is opened and the liquid feed pump TP is operated. When the sensor SNS-1 detects the sterilant (when it is in the ON state), the liquid feed pump TP is stopped, the extraction tube is moved above the liquid level of the sterilant, and the liquid feed pump TP is operated again. If the sensor SNS-2 detects the sterilant (becomes ON) before the sensor SNS-1 no longer detects the sterilant (becomes OFF), at least the second predetermined amount (for example, 3. It can be determined that 3 ml) of sterilant has been aspirated.

  Moreover, although the example which installed several (for example, two) sensor SNS was shown above, the detection of the amount of sterilant sucking out similar to the above can also be performed using one sensor SNS. FIG. 9 is a schematic diagram illustrating an example of installation of the sensor SNS. FIG. 10 is a schematic diagram illustrating an example of the configuration of the sensor SNS. As shown in FIGS. 9 and 10, in this example, the pipe connecting the liquid feed pump TP and the supply unit 30 is wound so as to loop, and the winding start portion 52 and the winding end portion 54 of the loop of the piping are Adjacent to each other. The sensor SNS is disposed so as to sandwich the adjacent winding start portion 52 and winding end portion 54. Specifically, the sensor SNS is provided at a position where the volume in the pipe from the tip of the extraction pipe to the sensor SNS becomes a first predetermined amount (for example, 3.4 ml). In addition to this, the sensor SNS has a second predetermined amount (for example, 3.3 ml) smaller than the first predetermined amount in the pipe from the sensor SNS through the looped pipe to the sensor SNS again. Is provided. Here, an example is shown in which the sensor SNS is disposed so as to sandwich the winding start portion 52 and the winding end portion 54, but the present invention is not limited to this. The sensor SNS should just be arrange | positioned so that the part before looping of piping and the part after looping may be pinched | interposed.

  As shown in FIG. 10, the sensor SNS includes a light emitting unit 56 and a light receiving unit 58 that face each other across a member in which a slit 57 is formed. Two pipes (a pipe at the winding start portion 52 and a pipe at the winding end portion 54) are arranged in the slit 57. The sensor SNS detects the presence or absence of liquid (sterilizing agent) in the pipe based on the amount of light received by the light receiving unit 58. That is, if the sterilizing agent is present in both of the two pipes, the light is largely blocked by the slit 57, so that the amount of light received by the light receiving unit 58 is reduced (first received light amount). On the other hand, if there is no sterilizing agent in either of the two pipes, light is transmitted through the slit 57 greatly, so that the amount of received light is increased (second received light amount). Further, if any of the two pipes has a sterilizing agent, light is partially blocked and transmitted through the slit 57, so that the amount of light received by the light receiving unit 58 is between the first received light amount and the second received light amount. Of the third received light amount. The sensor SNS has two pipes depending on whether the amount of light received by the light receiving unit 58 is the first received light amount, the second received light amount, or the third received light amount, or the proximity thereof. The presence or absence of a sterilant can be detected.

  The filling process of the sterilizing agent from the filling unit 50 to the supply unit 30 in this configuration is performed as follows. First, while the extraction tube is inserted into the cartridge 1052 and the tip of the extraction tube is positioned below the level of the sterilant, the solenoid valve SV5 is opened and the amount of light received by the light receiving unit 58 of the sensor SNS is the first. The liquid feed pump TP is operated until the amount of received light reaches three. That is, the liquid feed pump TP is operated until the sterilant is sucked up to the winding start portion 52 of the pipe. When the amount of light received by the light receiving unit 58 of the sensor SNS reaches the third amount of received light, the liquid feeding pump TP is stopped, the extraction tube is moved above the level of the sterilant, and the liquid feeding pump TP is operated again. The sensor SNS sucks out the second predetermined amount (for example, 3.3 ml) of the sterilizing agent at least when the amount of light received by the light receiving unit 58 of the sensor SNS becomes faster than the second amount of received light. Can be determined. That is, if the sensor SNS reacts at the winding end portion 54 of the pipe (becomes ON state) before the sensor SNS does not react at the pipe winding start portion 52 (becomes in the OFF state), at least second. It can be determined that a predetermined amount (eg, 3.3 ml) of the sterilant has been sucked out. 8 and 9, it is possible to reliably detect that a predetermined amount of the sterilizing agent has been sucked out from the filling unit 50 regardless of individual differences in the liquid feeding speed of the liquid feeding pump TP. That is, when the liquid feed pump TP is not a mechanism that can completely seal air, there may be individual differences in the liquid feed speed due to slight leakage when air is sent. For this reason, the time until the sensor SNS detects the sterilant after the liquid pump TP is operated when the sterilant is sucked out, and the liquid pump TP is operated with the extraction tube removed from the cartridge 1052. There is a possibility that an error may occur in the method of detecting the extraction amount of the sterilizing agent by comparing the time until the sensor SNS no longer detects the sterilizing agent. On the other hand, according to this configuration, since the extraction amount of the sterilizing agent is not detected by comparing the time, a predetermined amount of water is supplied from the filling unit 50 regardless of individual differences in the liquid feeding speed of the liquid feeding pump TP. It is possible to reliably detect that the sterilant has been sucked out, and to prevent sterilization failure due to insufficient extraction amount.

(1) Effect by switching the number of cracking catalyst units through which gas passes during decompression As described above, in the sterilization apparatus according to the present invention, the first cracking unit includes a plurality of cracking catalyst units and the gas passes through during decompression. Switching means for switching the number of the cracking catalyst units. In order to verify the effect of adopting such a configuration, the following experiment was conducted.

Example 1
In the decompression step, by opening the solenoid valve SV2, the cracking catalyst unit through which gas passes in the first cracking unit 70 is only the first cracking catalyst unit 70A. And the time required until the pressure of the sterilization chamber 20 became 100 Pa from the time of pressure reduction start was measured.

(Comparative Example 1)
In the depressurization step, by opening the solenoid valve SV3 instead of the solenoid valve SV2, the cracking catalyst units through which the gas passes in the first cracking unit 70 are changed to the first cracking catalyst unit 70A and the second cracking catalyst unit 70B. It was And the time required until the pressure of the sterilization chamber 20 became 100 Pa from the time of pressure reduction start was measured.
The above results are shown in Table 1 below.

  As is clear from the results of Table 1, in the case of Example 1, compared with the case of Comparative Example 1, the time required for the pressure in the sterilization chamber 20 to reach 100 Pa from the start of decompression can be reduced by 19 seconds. did it. That is, for example, when the process of reducing the pressure in the sterilization chamber 20 to 100 Pa is performed six times, it has been found that the total required time can be shortened by about 2 minutes. That is, it has been found that this enables more efficient sterilization than in the past.

(2) Measurement of the number of surviving bacteria Next, an experiment was performed to confirm that sterilization was appropriately performed by the sterilization apparatus and the sterilization method according to the present invention. As an object to be sterilized, 10 ⁶ CFU Geobacillus stearothermophilus (ATCC 7935) spore was set as an indicator bacterium in a lumen connected to a Teflon (registered trademark) tube having a diameter of 0.5 mm and a length of 10,000 mm at both ends. Was used. And sterilization was performed by the half cycle method while changing the sterilization time, and the number of colonies after culture was plotted against the sterilization time. The result is shown in FIG.

  As shown in FIG. 11, the survival cell count could be reduced to zero by taking a sterilization time of 6 minutes or more. That is, it was found that sufficient sterilization performance can be achieved by the sterilization apparatus and sterilization method according to the present invention.

DESCRIPTION OF SYMBOLS 10 ... Sterilizer; 20 ... Sterilization chamber; 30 ... Supply unit; 31 ... Member with several holes; 31H ... Hole; 40 ... Evaporating part; 41 ... Evaporating dish; 45 ... Concentration measuring means; 45C: Measuring unit (probe); 50 ... Filling unit; 52 ... Winding start part; 54 ... Winding end part; 56 ... Light emitting part; 57 ... Slit; 58 ... Light receiving part; 1 cracking unit; 70A ... 1st cracking catalyst unit; 70B ... 2nd cracking catalyst unit; 71 ... 2nd cracking unit; 80 ... residual liquid recovery unit; 90 ... dehumidification unit; 91 ... filter; G1 ... groove; PG1, PG2, PG3 ... pressure gauge; RP ... rotary pump; Sep ... oil mist separator; SNS ... sensor; SV0, SV1, SV2, SV3, SV4, SV5, SV ... Solenoid valve; SV7, SV8 ... three-way solenoid valve; SV9, SV10 ... Solenoid valve; SV11 ... three-way solenoid valve; SV12, SV13, SV14, SV15, SV16 ... Solenoid valve; TP ... feeding pump

Claims (18)

A sterilization chamber for storing objects to be sterilized;
A supply unit for supplying a sterilant containing hydrogen peroxide into the sterilization chamber;
A decompression unit for decompressing the sterilization chamber;
A sterilization apparatus comprising a first decomposition unit for decomposing the hydrogen peroxide during the decompression,
The first decomposition unit includes a plurality of decomposition catalyst units and switching means for switching the number of the decomposition catalyst units through which gas passes during the decompression.   When the first decomposition unit is depressurized by the decompression unit before supplying the hydrogen peroxide into the sterilization chamber, the gas passes through a smaller number of the decomposition catalyst units and enters the sterilization chamber into the sterilization chamber. The sterilizer according to claim 1, wherein the gas is passed through a larger number of the decomposition catalyst units when the pressure is reduced by the pressure reduction unit after hydrogen peroxide is supplied.   When the first decomposition unit is depressurized by the depressurization unit before supplying the hydrogen peroxide into the sterilization chamber, the gas passes through one decomposition catalyst unit, and the peroxidation unit enters the sterilization chamber. The sterilizer according to claim 1, wherein the gas is passed through two or more of the cracking catalyst units when the pressure is reduced by the pressure reducing unit after supplying hydrogen. Concentration measuring means for detecting the concentration of hydrogen peroxide gas in the sterilization chamber;
The sterilizer according to any one of claims 1 to 3, further comprising a control unit that adjusts a supply amount of the sterilant into the sterilization chamber according to the concentration of the hydrogen peroxide gas.   The concentration measuring means for detecting the concentration of hydrogen peroxide gas in the sterilization chamber is further provided, the concentration measuring means is provided with a light source and a photometer, and the light source is a monochromatic light source. The sterilizer according to item.   The sterilizer according to any one of claims 1 to 5, wherein a member having a plurality of holes is provided above the liquid level of the sterilizing agent in the supply unit.   The sterilizer according to any one of claims 1 to 6, wherein the supply unit is configured such that the sterilizing agent in the supply unit is concentrated by the decompression unit.   The sterilizer according to any one of claims 1 to 7, further comprising a second decomposition unit that decomposes hydrogen peroxide vaporized when the sterilant is concentrated or collected.   The sterilizer according to any one of claims 1 to 8, further comprising a residual liquid recovery unit that recovers the sterilant present in the supply unit.   The sterilizer according to claim 9, further comprising a filling unit that fills the supply unit with the sterilizing agent, wherein the residual liquid collecting unit is also configured to collect the sterilizing agent present in the filling unit. .   The sterilizer according to any one of claims 1 to 10, further comprising a dehumidifying unit connected to the sterilization chamber and configured to dehumidify air flowing into the sterilization chamber.   The sterilization chamber includes an inlet for introducing air and a connection port with the first decomposition unit, and the inlet has the opposite direction to the direction toward the connection port. The sterilizer according to any one of claims 1 to 11, further comprising a nozzle configured to cause the air flow in the sterilization chamber.   The sterilizer according to any one of claims 1 to 12, wherein the supply unit, the sterilization chamber, and the first decomposition unit are configured not to exceed atmospheric pressure. Storing a material to be sterilized in a sterilization chamber;
A first decompression step of decompressing the sterilization chamber;
A supply step of supplying a sterilant containing hydrogen peroxide into the sterilization chamber after the first decompression step;
A sterilization method including a second decompression step of decompressing the sterilization chamber after the supply step,
The sterilization method is configured such that gas passes through a smaller number of cracking catalyst units in the first pressure reducing step, and gas passes through a larger number of cracked catalyst units in the second pressure reducing step.   The sterilization method according to claim 14, further comprising a step of selecting whether or not to concentrate the sterilizing agent before the supplying step.   The sterilization method according to claim 14 or 15, further comprising a step of concentrating the sterilizing agent before the supplying step.   17. The method according to claim 14, further comprising a step of heating the object to be sterilized in the sterilization chamber by introducing air into the sterilization chamber between the first decompression step and the supply step. The sterilization method according to item.   The sterilization method according to claim 17, further comprising a step of dehumidifying the air before the air is introduced into the sterilization chamber.