Method for removing sterilization gas and sterilization apparatus

Abstract

To efficiently remove sterilization gas from the object to be sterilized. [Solution] The sterilization apparatus 100 comprises a chamber 11 in which the object to be sterilized is contained, a hydrogen peroxide supply unit 20 and an ozone supply unit 30 which are sterilization gas supply units that supply sterilization gas to the inside of the chamber 11 during the sterilization process of the object to be sterilized, a depressurization unit 40 which depressurizes the inside of the chamber 11 during the removal process to remove sterilization gas from the object to be sterilized, and a repressurization unit 50 which repressurizes the inside of the chamber 11 during the removal process. The repressurization unit 50 supplies a displacement gas to the inside of the chamber 11 that has a gas permeability to the object to be sterilized that is higher than that of air.

Description

[Technical Field]

[0001] The technologies disclosed herein relate to methods for removing sterilization gases and sterilization apparatus. [Background technology]

[0002] In the technical field related to sterilization equipment, a sterilization device such as the one disclosed in Patent Document 1 is known. In Patent Document 1, an aeration process is performed after the sterilization process. The sterilization process is a process of sterilizing the object to be sterilized with a sterilization gas. The aeration process is a process of removing the sterilization gas from the object to be sterilized. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Patent No. 6930684 [Overview of the project] [Problems that the invention aims to solve]

[0004] In the aeration process disclosed in Patent Document 1, the process of reducing the pressure inside the chamber and the process of injecting air into the chamber are repeated a specified number of times. There is a need for a technology that can efficiently remove sterilization gas from the object to be sterilized.

[0005] The technology disclosed herein aims to efficiently remove sterilization gases from objects to be sterilized. [Means for solving the problem]

[0006] This specification discloses a method for removing sterilization gas from an object to be sterilized in a chamber and sterilized with sterilization gas. The method for removing sterilization gas includes a depressurization step of reducing the pressure inside the chamber and a repressurization step of restoring pressure inside the chamber. In the repressurization step, a displacement gas with a gas permeability to the object to be sterilized that is higher than that of air is supplied to the inside of the chamber. [Effects of the Invention]

[0007] According to the technology disclosed herein, sterilization gases are efficiently removed from the object to be sterilized. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a schematic diagram showing a sterilization apparatus according to an embodiment. [Figure 2] Figure 2 is a flowchart showing the operation of the sterilization apparatus according to this embodiment. [Figure 3] Figure 3 is a flowchart showing the removal process according to the embodiment. [Modes for carrying out the invention]

[0009] [Sterilizer] Figure 1 is a schematic diagram showing a sterilization apparatus 100 according to an embodiment. The sterilization apparatus 100 sterilizes the object to be sterilized with a sterilization gas. In this embodiment, the sterilization gas includes hydrogen peroxide gas (H2O2) and ozone gas (O3).

[0010] Examples of items to be sterilized include medical instruments. Examples of medical instruments include steel products, synthetic resin products, and rubber products. Examples of steel products include forceps, clamps, and scissors. Examples of synthetic resin or rubber products include tubes.

[0011] The sterilization apparatus 100 comprises a chamber unit 10, a hydrogen peroxide supply unit 20, an ozone supply unit 30, a depressurization unit 40, a repressurization unit 50, and a control unit 60.

[0012] The chamber unit 10 includes a chamber 11 with a door 12, a heating unit 13, a pressure sensor 14, and a temperature sensor 15.

[0013] Chamber 11 has an internal space where the sterilization target is placed. The sterilization target is housed in Chamber 11. Door 12 opens and closes an opening provided in Chamber 11. The sterilization target is carried into the interior of Chamber 11 through the opening of Chamber 11. When Door 12 is closed, the interior of Chamber 11 is sealed.

[0014] The heating unit 13 is connected to Chamber 11. The heating unit 13 adjusts the temperature inside Chamber 11.

[0015] The pressure sensor 14 is connected to Chamber 11. The pressure sensor 14 detects the pressure inside Chamber 11.

[0016] The temperature sensor 15 is connected to Chamber 11. The temperature sensor 15 detects the temperature inside Chamber 11.

[0017] The hydrogen peroxide supply unit 20 supplies hydrogen peroxide gas as a sterilizing gas into the interior of Chamber 11 in the sterilization process of the sterilization target. The hydrogen peroxide supply unit 20 functions as a sterilizing gas supply unit that supplies a sterilizing gas into the interior of Chamber 11 in the sterilization process of the sterilization target. The hydrogen peroxide supply unit 20 includes a bottle 21, an extraction line 22, a tube pump 23, a storage unit 24, an evaporator 26, and a heater 29.

[0018] The bottle 21 contains an aqueous solution of hydrogen peroxide.

[0019] The extraction line 22 connects the bottle 21 and the storage unit 24. The aqueous solution of hydrogen peroxide extracted from the bottle 21 is supplied to the storage unit 24 through the extraction line 22.

[0020] The tube pump 23 is arranged in the extraction line 22. The tube pump 23 operates so that the aqueous solution of hydrogen peroxide is supplied from the bottle 21 to the storage unit 24.

[0021] The storage unit 24 temporarily stores a specified amount of aqueous hydrogen peroxide solution extracted from the bottle 21. In this embodiment, ambient air (atmosphere) surrounding the storage unit 24 is introduced into the storage unit 24 via a filter 25. The pressure in the storage unit 24 is atmospheric pressure. A HEPA filter is exemplified as the filter 25.

[0022] The evaporator 26 is connected to the storage unit 24 via a supply line 27. The evaporator 26 evaporates the aqueous solution of hydrogen peroxide supplied from the storage unit 24 to produce hydrogen peroxide gas.

[0023] A valve 70 is located in the supply line 27. A solenoid valve is exemplified as the valve 70. When the valve 70 opens, the aqueous hydrogen peroxide solution in the storage unit 24 is drawn into the depressurized evaporator 26. As described above, the surrounding air (atmosphere) is introduced into the storage unit 24 via the filter 25. When the valve 70 opens, air (atmosphere) is drawn into the evaporator 26 along with the aqueous hydrogen peroxide solution.

[0024] The evaporator 26 is connected to the chamber 11 via injection lines 28a and 28b. Valve 71 is located on injection line 28a, and valve 72 is located on injection line 28b. Solenoid valves are exemplified as valves 71 and 72. When hydrogen peroxide gas is generated in the evaporator 26 and the pressure in the evaporator 26 becomes high, valve 71 or valve 72 opens, supplying hydrogen peroxide gas into the chamber 11. A pressure sensor 39 is connected to the evaporator 26. Based on the data detected by the pressure sensor 39, it is determined whether a specified amount of hydrogen peroxide gas has been supplied to the chamber 11.

[0025] The heater 29 adjusts the temperature of the evaporator 26. The heater 29 maintains the evaporator 26 at a predetermined temperature.

[0026] The ozone supply unit 30 supplies a mixed gas containing ozone gas as a sterilization gas to the inside of the chamber 11 during the sterilization process of the object to be sterilized. The ozone supply unit 30 functions as a sterilization gas supply unit that supplies sterilization gas to the inside of the chamber 11 during the sterilization process of the object to be sterilized. The ozone supply unit 30 includes an oxygen generator 31, an ozone generator 32, an ozone concentration sensor 33, a buffer tank 34, and a pressure sensor 35.

[0027] The oxygen generator 31 produces oxygen (O2), which is the raw material for ozone. An example of the oxygen generator 31 is the PSA (Pressure Swing Adsorption) method, which produces high-concentration oxygen by adsorbing nitrogen from the air onto an adsorbent such as zeolite. A valve 73 is placed in the connection line 81 that connects the oxygen generator 31 and the ozone generator 32. In this embodiment, the valve 73 is a three-way valve. The valve 73 adjusts the amount of oxygen supplied from the oxygen generator 31 to the ozone generator 32.

[0028] The ozone generator 32 generates ozone gas from the oxygen generated by the oxygen generator 31. An example of the ozone generator 32 is a silent discharge method that generates ozone by applying a high-frequency high voltage to oxygen to cause discharge and decomposition. In this embodiment, the ozone supply unit 30 has two ozone generators 32. The ozone generators 32 are connected to the buffer tank 34 via a supply line 36.

[0029] The ozone concentration sensor 33 is located in the supply line 36. The ozone concentration sensor 33 detects the concentration of ozone gas generated by the ozone generator 32.

[0030] A valve 74 is located in the supply line 36 between the ozone concentration sensor 33 and the buffer tank 34. A solenoid valve is exemplified as valve 74. The supply line 36 between the ozone concentration sensor 33 and valve 74 is connected to the pressure reducing unit 40 via a piping system X that includes a valve 75. A solenoid valve is exemplified as valve 75. When valve 74 is closed and valve 75 is open, ozone gas from the ozone generator 32 is supplied to the pressure reducing unit 40.

[0031] The buffer tank 34 temporarily stores the ozone gas generated by the ozone generator 32. The buffer tank 34 is connected to the evaporator 26 via a supply line 37. A valve 76 is located in the supply line 37. A solenoid valve is exemplified as the valve 76. When ozone gas is supplied to the buffer tank 34 with the valve 76 closed, the pressure in the buffer tank 34 increases.

[0032] The pressure sensor 35 is connected to the buffer tank 34. The pressure sensor 35 detects the pressure in the buffer tank 34. Based on the data detected by the pressure sensor 35, it is determined whether or not ozone is being supplied to the buffer tank 34 up to a predetermined pressure, or whether or not an ozone leak or blockage has occurred.

[0033] Ozone gas supplied from the buffer tank 34 is supplied to the chamber 11 via the evaporator 26.

[0034] The depressurization unit 40 discharges gas from inside the chamber 11. The depressurization unit 40 also reduces the pressure inside the chamber 11 by discharging gas from inside the chamber 11. The depressurization unit 40 includes a vacuum pump 41, a first catalyst tank 42, a second catalyst tank 43, a first heater 44, and a second heater 45.

[0035] The vacuum pump 41 is connected to the chamber 11 via an exhaust line 38. The vacuum pump 41 operates to expel gas from inside the chamber 11. A valve 77 is located in the exhaust line 38. A solenoid valve is exemplified as the valve 77. When the pressure inside the chamber 11 is reduced, the valve 77 closes and the vacuum pump 41 stops when the pressure inside the chamber 11 reaches a predetermined value.

[0036] The first catalyst tank 42 is located upstream of the vacuum pump 41. The second catalyst tank 43 is located downstream of the vacuum pump 41. The catalyst, for example, mainly consists of manganese dioxide, and decomposes hydrogen peroxide and ozone.

[0037] The first heater 44 keeps the first catalyst tank 42 warm. The second heater 45 keeps the second catalyst tank 43 warm.

[0038] The repressurization unit 50 restores pressure inside the chamber 11, which has been depressurized by the depressurization unit 40. The repressurization unit 50 restores pressure inside the chamber 11 by introducing outside air (atmosphere) into the chamber 11. The repressurization unit 50 includes a filter 51, an introduction line 52, and a buffer tank 53.

[0039] The filter 51 collects foreign matter from the air (atmosphere) introduced into the chamber 11. Examples of the filter 51 include a nonwoven fabric filter or a HEPA filter.

[0040] The introduction line 52 connects the internal and external spaces of the chamber 11. Air (atmosphere) introduced into the chamber 11 from outside flows through the introduction line 52. Air (atmosphere) from outside the chamber 11 is introduced into the chamber 11 via the filter 51.

[0041] A valve 78 is positioned in the introduction line 52. A solenoid valve is exemplified as the valve 78. The valve 78 adjusts the airflow rate in the introduction line 52. When the valve 78 is open, outside air (atmosphere) is introduced into the chamber 11 via the introduction line 52. When the valve 78 is closed, the introduction of air (atmosphere) into the chamber 11 is stopped.

[0042] The oxygen generator 31 is connected to the repressurization unit 50 via a valve 73 and a connecting line 82. The connecting line 82 connects the valve 73 to the buffer tank 53. The buffer tank 53 is connected to the filter 51 via a supply line 54. The oxygen generator 31 is connected to the filter 51 via the valve 73, the connecting line 82, the buffer tank 53, and the supply line 54.

[0043] As described above, valve 73 is a three-way valve. Valve 73 operates to switch between a first state in which oxygen generated by the oxygen generator 31 is supplied to the ozone supply unit 30 (ozone generator 32), and a second state in which oxygen generated by the oxygen generator 31 is supplied to the repressurization unit 50 (buffer tank 53). When valve 73 is in the first state, oxygen generated by the oxygen generator 31 is supplied to the ozone supply unit 30 but not to the repressurization unit 50. When valve 73 is in the second state, oxygen generated by the oxygen generator 31 is supplied to the repressurization unit 50 but not to the ozone supply unit 30.

[0044] The buffer tank 53 of the repressurization unit 50 temporarily stores the oxygen generated by the oxygen generator 31. The oxygen in the buffer tank 53 is supplied to the filter 51 via the supply line 54. The oxygen supplied from the buffer tank 53 to the filter 51 is mixed with the outside air (atmosphere) of the chamber 11 in the filter 51 and then introduced into the chamber 11.

[0045] The control unit 60 controls the components of the sterilizer 100. The control unit 60 includes a control device 61 and an input device 62. The control device 61 includes a computer system. An example of the input device 62 is a touch panel or a computer keyboard. The control device 61 can control the components of the sterilizer 100 based, for example, on input data entered via the input device 62.

[0046] [Sterilization device operation] Figure 2 is a flowchart showing the operation of the sterilization apparatus 100 according to the embodiment. In the embodiment, the sterilization apparatus 100 performs a sterilization process S1 and a removal process S2. Sterilization process S1 is a process of sterilizing the object to be sterilized contained in the chamber 11 with a sterilization gas. In the embodiment, the object to be sterilized is sterilized with a sterilization gas containing hydrogen peroxide gas and ozone gas. The removal process S2 is performed after sterilization process S1. The removal process S2 is a process of removing the sterilization gas from the object to be sterilized contained in the chamber 11 and sterilized with the sterilization gas.

[0047] <Sterilization> After the items to be sterilized are placed inside the chamber 11 and the door 12 is closed, the sterilization process S1 of the items to be sterilized is started. During the sterilization process S1 of the items to be sterilized, the control device 61 controls the valve 73 so that it is in the first state. That is, during the sterilization process S1, the oxygen generated by the oxygen generator 31 is supplied to the ozone supply unit 30 (ozone generator 32), and the valve 73 is controlled so that the oxygen generated by the oxygen generator 31 is not supplied to the repressurization unit 50 (buffer tank 53).

[0048] In sterilization process S1, hydrogen peroxide gas is supplied to the chamber 11 as a sterilization gas from the hydrogen peroxide supply unit 20, and a mixed gas containing ozone gas is supplied to the chamber 11 as a sterilization gas from the ozone supply unit 30. Sterilization process S1 includes a sterilization decompression step of reducing the pressure inside the chamber 11, as disclosed in, for example, Japanese Patent Publication No. 6930684, and a sterilization step performed under reduced pressure in the sterilization decompression step. The sterilization step includes a first steam injection step of injecting hydrogen peroxide gas into the chamber 11, an ozone injection step of injecting ozone gas into the chamber 11 after the first steam injection step, and a second steam injection step of injecting hydrogen peroxide gas into the chamber 11 after the ozone injection step. The sterilization decompression step and the sterilization step are repeated the required number of times. The control device 61 supplies hydrogen peroxide gas to the chamber 11 as a sterilization gas from the hydrogen peroxide supply unit 20 during the first steam injection step and the second steam injection step. In the ozone injection process, the control device 61 supplies a mixed gas containing ozone gas as a sterilization gas from the ozone supply unit 30 into the chamber 11. In the second steam injection process, steam generated from water or steam generated from a solution containing sodium hypochlorite or alcohols may be injected into the chamber 11.

[0049] <Removal process> After the sterilization process S1 is completed, the removal process S2 is started to remove sterilization gas from the items to be sterilized. After the sterilization process S1 is completed, the removal process S2 is started while the airtight seal inside the chamber 11 by the door 12 is maintained.

[0050] In an embodiment, the control device 61 supplies a replacement gas having a gas permeability higher than that of air to the inside of the chamber 11 to remove the sterilizing gas from the sterilization target. There is a possibility that the sterilizing gas may penetrate into the sterilization target during the sterilization process S1. When the sterilization target is made of synthetic resin or rubber, the sterilizing gas may easily penetrate into the sterilization target. By supplying a replacement gas having a high gas permeability to the inside of the chamber 11, the sterilizing gas penetrating into the sterilization target is replaced with the replacement gas. That is, by supplying a replacement gas having a high gas permeability to the inside of the chamber 11, the sterilizing gas penetrating into the sterilization target is discharged from the sterilization target by the replacement gas.

[0051] Gas permeability refers to the physical property representing the ability of the material constituting the sterilization target to allow gas to permeate. The gas permeability [m 3 / m 2 / sPa] represents a value indicating the ease of gas permeation. The higher the gas permeability, the easier the gas permeates the sterilization target. Examples of replacement gases having a gas permeability higher than that of air with respect to the sterilization target include oxygen and carbon dioxide.

[0052] For example, when the material constituting the sterilization target is silicone rubber, the gas permeation amount of nitrogen (N2) in a 50°C atmosphere is about 280 [×10 -8 cc,cm / cm 2 ,sec,atm], the gas permeation amount of oxygen (O2) is about 500 [×10 -8 cc,cm / cm 2 ,sec,atm], and the gas permeation amount of carbon dioxide (CO2) is about 1550 [×10 -8 cc,cm / cm 2 ,sec,atm]. For example, when the material constituting the sterilization target is ethylene propylene rubber, the gas permeation amount of nitrogen (N2) in a 50°C atmosphere is about 13.7 [×10 -8 cc,cm / cm 2 ,sec,atm], the gas permeation amount of oxygen (O2) is about 46.6 [×10 -8 cc,cm / cm 2 ,sec,atm], and the gas permeation amount of carbon dioxide (CO2) is about 183 [×10 -8 [[ID=2 [,sec,atm]. Thus, the gas permeability (gas permeation rate) to the object to be sterilized varies depending on the type of gas. Furthermore, the gas permeability (gas permeation rate) varies depending on the material constituting the object to be sterilized. Furthermore, the gas permeability (gas permeation rate) varies depending on the ambient temperature.

[0053] In this embodiment, oxygen generated by the oxygen generator 31 is used as the displacement gas. Oxygen permeates through the object to be sterilized more easily than air. As the displacement gas containing oxygen permeates through the object to be sterilized, the sterilization gas that has permeated the object is driven out by the displacement gas.

[0054] In the removal process S2, the control device 61 controls the valve 73 so that it enters the second state. That is, in the removal process S2, the oxygen generated by the oxygen generator 31 is supplied to the repressurization unit 50 (buffer tank 53), and the valve 73 is controlled so that the oxygen generated by the oxygen generator 31 is not supplied to the ozone supply unit 30 (ozone generator 32).

[0055] In the removal process S2, a depressurization step is performed to reduce the pressure inside the chamber 11, and a repressurization step is performed to restore pressure inside the chamber 11. The depressurization unit 40 reduces the pressure inside the chamber 11 in the removal process S2. The repressurization unit 50 restores pressure inside the chamber 11 in the removal process S2. After the pressure inside the chamber 11 has been reduced by the depressurization unit 40, the control device 61 restores pressure inside the chamber 11 using the repressurization unit 50. The control device 61 repeats the depressurization step and the repressurization step a specified number of times.

[0056] In the repressurization process, the repressurization unit 50 supplies a replacement gas to the chamber 11 with a gas permeability to the sterilization object that is higher than that of air. In this embodiment, the repressurization unit 50 generates the replacement gas by mixing oxygen generated by the oxygen generator 31 with air. As described above, in the removal process S2, the valve 73 is controlled to enter the second state. The oxygen generated by the oxygen generator 31 is supplied to the filter 51 via the valve 73, connection line 82, buffer tank 53, and supply line 54. The oxygen supplied from the oxygen generator 31 to the filter 51 is mixed with outside air (atmosphere) in the filter 51 before being introduced into the chamber 11. That is, in this embodiment, the replacement gas is generated by mixing oxygen generated by the oxygen generator 31 with air. The oxygen concentration of the replacement gas is higher than that of the air. The repressurization unit 50 mixes the oxygen generated by the oxygen generator 31 with the air outside the chamber 11 to produce a displacement gas, which is then introduced into the chamber 11.

[0057] The depressurization process removes at least a portion of the sterilization gas that has permeated the object to be sterilized. In the repressurization process, a displacement gas with a higher gas permeability than air is supplied into the chamber 11, effectively removing the sterilization gas that has permeated the object to be sterilized. By supplying a displacement gas with a higher gas permeability than air into the chamber 11, the sterilization gas that has permeated the object to be sterilized is removed efficiently in a short time.

[0058] Figure 3 is a flowchart of the removal process S2 according to the embodiment. After the sterilization process S1 is completed, the control device 61 starts the removal process S2. The control device 61 controls the depressurization unit 40 so that the inside of the chamber 11 is depressurized (step S21). After the inside of the chamber 11 is depressurized, the control device 61 controls the repressurization unit 50 so that the inside of the chamber 11 is repressurized (step S22). In the repressurization process S22, a replacement gas is supplied to the inside of the chamber 11. The replacement gas permeates the object to be sterilized more easily than air. As the replacement gas permeates the object to be sterilized, the sterilization gas that has permeated the object is driven out of the object by the replacement gas.

[0059] The control device 61 determines whether the depressurization process and the repressurization process have been repeated a specified number of times (step S23). If, in step S23, it is determined that the depressurization process and the repressurization process have not been repeated a specified number of times (step S23: No), the control device 61 returns to the process in step S21. If it is determined that the depressurization process and the repressurization process have been repeated a specified number of times (step S23: Yes), the control device 61 terminates the removal process S2.

[0060] [effect] As described above, in this embodiment, the sterilization apparatus 100 includes a chamber 11 in which the object to be sterilized is contained, a hydrogen peroxide supply unit 20 and an ozone supply unit 30 which are sterilization gas supply units that supply sterilization gas to the inside of the chamber 11 during the sterilization process of the object to be sterilized, a depressurization unit 40 which depressurizes the inside of the chamber 11 during the removal process S2 in which sterilization gas is removed from the object to be sterilized, and a repressurization unit 50 which repressurizes the inside of the chamber 11 during the removal process S2. The repressurization unit 50 supplies a displacement gas to the inside of the chamber 11 that has a gas permeability to the object to be sterilized that is higher than that of air.

[0061] According to the embodiment, in the removal process S2 for removing sterilization gas from the object to be sterilized, a depressurization step and a repressurization step are performed. In the depressurization step, at least a portion of the sterilization gas that has permeated the object to be sterilized is removed from the object to be sterilized. In the repressurization step, a displacement gas with a gas permeability higher than that of air is supplied into the chamber 11, so that the sterilization gas that has permeated the object to be sterilized is driven out by the displacement gas. By supplying a displacement gas with a gas permeability higher than that of air into the chamber 11, the sterilization gas that has permeated the object to be sterilized is effectively removed from the object to be sterilized. By supplying a displacement gas into the chamber 11, the sterilization gas that has permeated the object to be sterilized is removed efficiently in a short time.

[0062] The ozone supply unit 30, which is a sterilization gas supply unit, includes an oxygen generator 31 that generates oxygen and an ozone generator 32 that generates ozone gas as a sterilization gas from the oxygen generated by the oxygen generator 31. The repressurization unit 50 mixes the oxygen generated by the oxygen generator 31 with air (atmosphere) to produce a displacement gas. This allows for the efficient and low-cost production of a displacement gas with a higher gas permeability than air.

[0063] [Other embodiments] In the above embodiment, the displacement gas is generated by mixing oxygen and air. Carbon dioxide may be used as the displacement gas, which has a higher gas permeability to the object to be sterilized than air. The displacement gas may also be generated by mixing air and carbon dioxide. The carbon dioxide concentration of the displacement gas is higher than the carbon dioxide concentration of the air. Alternatively, only oxygen may be supplied to the chamber 11 as the displacement gas. Alternatively, only carbon dioxide may be supplied to the chamber 11 as the displacement gas.

[0064] In the embodiments described above, the sterilization gases were assumed to be hydrogen peroxide gas and ozone gas. However, the sterilization gases are not limited to hydrogen peroxide gas and ozone gas. The sterilization gases may be formaldehyde, as disclosed in Japanese Patent Application Publication No. 2018-110793, ethylene oxide gas or formalin gas, as disclosed in Japanese Patent Application Publication No. 2015-229034, or chlorine dioxide gas. [Explanation of symbols]

[0065] 10...Chamber unit, 11...Chamber, 12...Door, 13...Heating unit, 14...Pressure sensor, 15...Temperature sensor, 20...Hydrogen peroxide supply unit, 21...Bottle, 22...Extraction line, 23...Tube pump, 24...Storage section, 25...Filter, 26...Evaporator, 27...Supply line, 28a...Injection line, 28b...Injection line, 29...Heater, 30...Ozone supply unit, 31...Oxygen generator, 32...Ozone generator, 33...Ozone concentration sensor, 34...Buffer tank, 35...Pressure sensor, 36...Supply line, 37...Supply line 38...Exhaust line, 39...Pressure sensor, 40...Depressurization unit, 41...Vacuum pump, 42...First catalyst tank, 43...Second catalyst tank, 44...First heater, 45...Second heater, 50...Restoration unit, 51...Filter, 52...Inlet line, 53...Buffer tank, 54...Supply line, 60...Control unit, 61...Control device, 62...Input device, 70...Valve, 71...Valve, 72...Valve, 73...Valve, 74...Valve, 75...Valve, 76...Valve, 77...Valve, 78...Valve, 81...Connection line, 82...Connection line, 100...Sterilization device.

Claims

1. A method for removing a sterilization gas from an object to be sterilized, which is contained in a chamber and sterilized by the sterilization gas, A depressurization step of reducing the pressure inside the chamber, The process includes a pressure restoration step of restoring pressure inside the chamber, In the repressurization step, a displacement gas with a gas permeability to the object to be sterilized that is higher than that of air is supplied to the inside of the chamber. Methods for removing sterilization gas.

2. The displacement gas is produced by mixing air with oxygen or carbon dioxide. A method for removing sterilization gas according to claim 1.

3. The sterilization gas is a mixed gas containing ozone gas generated from oxygen produced by an oxygen generator. The displacement gas is produced by mixing oxygen generated by the oxygen generator with air. A method for removing sterilization gas according to claim 1.

4. A chamber in which the items to be sterilized are contained, A sterilization gas supply unit that supplies sterilization gas to the inside of the chamber during the sterilization process of the object to be sterilized, A vacuum unit for reducing the pressure inside the chamber in a removal process for removing the sterilization gas from the object to be sterilized, The removal process includes a pressure restoration unit that restores pressure inside the chamber, The repressurization unit supplies a displacement gas to the chamber that has a gas permeability to the object to be sterilized that is higher than that of air. Sterilization equipment.

5. The aforementioned sterilization gas supply unit is An oxygen generator that produces oxygen, The system includes an ozone generator that generates ozone gas as a sterilization gas from the oxygen generated by the oxygen generator, The aforementioned pressure restoration unit is The oxygen generated by the oxygen generator is mixed with air to produce the displacement gas. The sterilization apparatus according to claim 4.

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