Method for removing hydrogen peroxide

Abstract

To remove hydrogen peroxide remaining in an object.SOLUTION: This method for removing hydrogen peroxide remaining in an object includes a decompression step (SB15) for decompressing the internal space of a chamber (11) in which the object is accommodated, a water vapor supply step (SB16) for supplying water vapor to the internal space in a state where the internal space is decompressed, and an air supply step (SB17) for supplying air to the internal space after the water vapor is supplied to the internal space.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The technology disclosed in this specification relates to a method for removing hydrogen peroxide. [Background technology]

[0002] In the technical field relating to sterilization devices, a sterilization device using hydrogen peroxide, such as that disclosed in Patent Document 1, is known. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2020 / 183696 Summary of the Invention [Problem to be solved by the invention]

[0004] There is a demand for a technique for removing hydrogen peroxide remaining on an object after the object has been sterilized with hydrogen peroxide.

[0005] The technology disclosed in this specification aims to remove hydrogen peroxide remaining on an object. [Means for solving the problem]

[0006] This specification discloses a method for removing hydrogen peroxide remaining in an object, which includes a depressurizing step of depressurizing an internal space of a chamber in which the object is housed, a water vapor supplying step of supplying water vapor to the internal space while the internal space is depressurized, and an air supplying step of supplying air to the internal space after the water vapor has been supplied to the internal space. Effect of the Invention

[0007] According to the technology disclosed in this specification, hydrogen peroxide remaining on an object is removed. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram showing a schematic diagram of a sterilization apparatus according to a first embodiment. [Diagram 2] FIG. 2 is a flowchart showing the operation of the sterilization apparatus according to the first embodiment. [Diagram 3] FIG. 3 is a flowchart showing the removal process according to the first embodiment. [Figure 4] FIG. 4 shows the change in the amount of hydrogen peroxide remaining on a 96-well plate during the reduced pressure drying process. [Diagram 5] FIG. 5 is a diagram for explaining the effect of the removal process according to the first embodiment. [Figure 6] FIG. 6 is a flowchart showing the removal process according to the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings, but the present disclosure is not limited to the embodiment. The components of the embodiments described below can be appropriately combined. In addition, some components may not be used.

[0010] [First embodiment] A first embodiment will be described.

[0011] <Sterilizer> FIG. 1 is a schematic diagram of a sterilization apparatus 100 according to the present embodiment. The sterilization apparatus 100 sterilizes an object using hydrogen peroxide gas (H2O2). An example of the object is a part used for cell culture. An example of the part is a petri dish and a well plate. The object may be a medical instrument. An example of the medical instrument is a steel product such as forceps, a pick, or a scissors, and a resin product such as a tube.

[0012] The sterilization apparatus 100 includes a chamber unit 10, a hydrogen peroxide supply unit 20, a steam cleaning unit 30, a decompression unit 40, a pressure recovery unit 50, and a control unit 60.

[0013] The chamber unit 10 includes a chamber 11 including a door 12 , a heating unit 13 , a pressure sensor 14 , and a temperature sensor 15 .

[0014] The chamber 11 contains an object. The chamber 11 has an internal space in which the object is placed. The door 12 opens and closes an opening provided in the chamber 11. The object is carried into the internal space of the chamber 11 through the opening of the chamber 11. When the door 12 is closed, the internal space of the chamber 11 is sealed.

[0015] The heating unit 13 is connected to the chamber 11. The heating unit 13 adjusts the temperature of the internal space of the chamber 11.

[0016] The pressure sensor 14 is connected to the chamber 11. The pressure sensor 14 detects the pressure in the internal space of the chamber 11.

[0017] The temperature sensor 15 is connected to the chamber 11. The temperature sensor 15 detects the temperature of the internal space of the chamber 11.

[0018] Hydrogen peroxide supply unit 20 supplies hydrogen peroxide gas to the internal space of chamber 11 during sterilization of an object. Hydrogen peroxide supply unit 20 includes bottle 21, extraction line 22, tube pump 23, storage unit 24, filter 25, evaporator 26, supply line 27, valve 28, and heater 29.

[0019] Bottle 21 contains an aqueous solution of hydrogen peroxide.

[0020] 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 via the extraction line 22.

[0021] A tube pump 23 is disposed in the extraction line 22. The tube pump 23 operates to feed the aqueous solution of hydrogen peroxide from the bottle 21 to the reservoir 24.

[0022] Storage unit 24 temporarily stores a specified amount of aqueous hydrogen peroxide solution extracted from bottle 21. Air (atmosphere) around storage unit 24 is introduced into storage unit 24 via filter 25. The pressure in storage unit 24 is atmospheric pressure. An example of filter 25 is a HEPA filter.

[0023] 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.

[0024] Valve 28 is disposed in supply line 27. An example of valve 28 is a solenoid valve. When valve 28 opens, the aqueous hydrogen peroxide solution in storage unit 24 is sucked into evaporator 26, the pressure of which has been reduced. As described above, air (atmosphere) around storage unit 24 is introduced into storage unit 24 via filter 25. When valve 28 opens, air (atmosphere) is sucked into evaporator 26 together with the aqueous hydrogen peroxide solution.

[0025] The evaporator 26 is connected to the chamber 11 via the injection line 16 and the injection line 17. A valve 71 is disposed in the injection line 16, and a valve 72 is disposed in the injection line 17. An example of the valves 71 and 72 is a solenoid valve. When hydrogen peroxide gas is generated in the evaporator 26 and the pressure of the evaporator 26 becomes high, the valve 71 or the valve 72 opens, and the hydrogen peroxide gas is supplied to the internal space of the chamber 11.

[0026] The heater 29 adjusts the temperature of the evaporator 26. The heater 29 maintains the evaporator 26 at a predetermined temperature.

[0027] The steam cleaning unit 30 supplies water vapor to the internal space of the chamber 11 in a hydrogen peroxide removal process carried out after a sterilization process. The steam cleaning unit 30 includes a bottle 31, an extraction line 32, a tube pump 33, a storage section 34, a filter 35, an evaporator 36, a supply line 37, a valve 38, and a heater 39.

[0028] The bottle 31 contains water.

[0029] The extraction line 32 connects the bottle 31 to the storage unit 34. The water extracted from the bottle 31 is supplied to the storage unit 34 via the extraction line 32.

[0030] A tube pump 33 is disposed in the brewing line 32. The tube pump 33 operates to pump water from the bottle 31 to the reservoir 34.

[0031] The storage unit 34 temporarily stores a specified amount of water extracted from the bottle 31. The air (atmosphere) around the storage unit 34 is introduced into the storage unit 34 via the filter 35. The pressure in the storage unit 34 is atmospheric pressure. An example of the filter 35 is a HEPA filter.

[0032] The evaporator 36 is connected to the storage unit 34 via a supply line 37. The evaporator 36 evaporates the water supplied from the storage unit 34 to generate water vapor.

[0033] The valve 38 is disposed in the supply line 37. An example of the valve 38 is a solenoid valve. When the valve 38 is opened, the water in the storage unit 34 is sucked into the depressurized evaporator 36. As described above, the air (atmosphere) around the storage unit 34 is introduced into the storage unit 34 via the filter 35. When the valve 38 is opened, the air (atmosphere) is sucked into the evaporator 36 together with the water.

[0034] The evaporator 36 is connected to the chamber 11 via the injection line 18 and the injection line 19. A valve 73 is disposed in the injection line 18, and a valve 74 is disposed in the injection line 19. An example of the valves 73 and 74 is a solenoid valve. When water vapor is generated in the evaporator 36 and the pressure of the evaporator 36 becomes high, the valve 73 or the valve 74 opens, and the water vapor is supplied to the internal space of the chamber 11.

[0035] The heater 39 adjusts the temperature of the evaporator 36. The heater 39 maintains the evaporator 36 at a predetermined temperature.

[0036] The decompression unit 40 exhausts gas from the internal space of the chamber 11. The decompression unit 40 reduces the pressure in the internal space of the chamber 11 by exhausting gas from the internal space of the chamber 11. The decompression unit 40 has a vacuum pump 41, a first catalyst tank 42, a second catalyst tank 43, a first heater 44, and a second heater 45.

[0037] The vacuum pump 41 is connected to the chamber 11 via an exhaust line 46. The vacuum pump 41 operates to exhaust gas from the internal space of the chamber 11. A valve 77 is disposed in the exhaust line 46. When the pressure in the internal space of the chamber 11 is to be reduced, the valve 77 is closed and the vacuum pump 41 is stopped when the pressure in the internal space of the chamber 11 reaches a predetermined value.

[0038] The first catalyst tank 42 is disposed upstream of the vacuum pump 41. The second catalyst tank 43 is disposed downstream of the vacuum pump 41. The catalyst contains, for example, manganese dioxide as a main component and decomposes hydrogen peroxide.

[0039] The first heater 44 keeps the first catalyst tank 42 warm. The second heater 45 keeps the second catalyst tank 43 warm.

[0040] The pressure regain unit 50 regains the pressure in the internal space of the chamber 11 that has been depressurized by the depressurization unit 40. The pressure regain unit 50 introduces air (atmosphere) in the external space of the chamber 11 into the internal space of the chamber 11 to regain the pressure in the internal space of the chamber 11. The pressure regain unit 50 has a filter 51 and an introduction line 52.

[0041] The filter 51 collects foreign matter from the air (atmosphere) introduced into the internal space of the chamber 11. An example of the filter 51 is a HEPA filter.

[0042] The introduction line 52 connects the internal space and the external space of the chamber 11. Air (atmosphere) introduced from the external space of the chamber 11 to the internal space of the chamber 11 flows through the introduction line 52. The air (atmosphere) in the external space of the chamber 11 is introduced into the internal space of the chamber 11 via the filter 51.

[0043] A valve 78 is disposed in the introduction line 52. An example of the valve 78 is a solenoid valve. The valve 78 adjusts the flow rate of air in the introduction line 52. When the valve 78 is opened, air (atmosphere) in the external space of the chamber 11 is introduced into the internal space of the chamber 11 via the introduction line 52. When the valve 78 is closed, the introduction of air (atmosphere) into the internal space of the chamber 11 is stopped.

[0044] The control unit 60 controls the components of the sterilization apparatus 100. The control unit 60 has a control device 61 and an input device 62. The control device 61 includes a computer system. Examples of the input device 62 include a touch panel or a computer keyboard. The control device 61 can control the components of the sterilization apparatus 100 based on input data input via the input device 62, for example.

[0045] <Operation of the sterilizer> Figure 2 is a flow chart showing the operation of the sterilization apparatus 100 according to this embodiment. In this embodiment, the sterilization apparatus 100 carries out a sterilization process SA and a removal process SB. The removal process SB is carried out after the sterilization process SA. The removal process SB is a process for removing hydrogen peroxide remaining in the object after the sterilization process SB.

[0046] (Sterilization) When an object is to be sterilized, the object is placed inside the chamber 11. A user of the sterilization apparatus 100 carries the object into the internal space of the chamber 11 through the opening of the chamber 11. After the object is placed in the internal space of the chamber 11, the user closes the door 12. By closing the door 12, the internal space of the chamber 11 is sealed.

[0047] After the internal space of chamber 11 is sealed, control device 61 controls decompression unit 40 to exhaust gas from the internal space of chamber 11. After the gas is exhausted from the internal space of chamber 11, control device 61 controls hydrogen peroxide supply unit 20 to supply hydrogen peroxide gas to the internal space of chamber 11. Control device 61 controls heating unit 13 to heat the internal space of chamber 11 to a predetermined sterilization temperature. With the internal space of chamber 11 heated to the sterilization temperature, hydrogen peroxide gas is supplied to the internal space of chamber 11. As an example, the sterilization temperature is about 50°C. By supplying hydrogen peroxide gas to the internal space of chamber 11, the hydrogen peroxide gas comes into contact with the surface of the object, and the object is sterilized with hydrogen peroxide.

[0048] (Removal process) After the sterilization process is completed, a removal process SB is carried out to remove hydrogen peroxide remaining in the object. Fig. 3 is a flowchart showing the removal process SB according to this embodiment. In this embodiment, the removal process SB includes a reduced pressure drying process SB11, a water vapor supplying process SB12, an atmosphere supplying process SB13, an atmosphere holding process SB14, a reduced pressure process SB15, a water vapor supplying process SB16, an atmosphere supplying process SB17, and an atmosphere holding process SB18.

[0049] After the sterilization process is completed, a reduced pressure drying step SB11 is performed with the object housed in the chamber 11. In the reduced pressure drying step SB11, the control device 61 controls the decompression unit 40 so that the internal space of the chamber 11 in which the object is housed is decompressed. In the reduced pressure drying step SB11, the control device 61 decompresses the internal space of the chamber 11 so that the pressure in the internal space of the chamber 11 becomes approximately 10 Pa (second pressure). In the reduced pressure drying step SB11, the control device 61 controls the heating unit 13 so that the temperature of the internal space of the chamber 11 becomes a reduced pressure drying temperature that is higher than the sterilization temperature. As an example, the reduced pressure drying temperature is approximately 80°C.

[0050] In the reduced pressure drying step SB11, the pressure in the internal space of the chamber 11 is adjusted to about 10 Pa, and the temperature is adjusted to about 80° C., and this state is maintained for about 24 hours (second time).

[0051] In the reduced pressure drying step SB11, when the internal space of the chamber 11 is decompressed, the hydrogen peroxide remaining in the object evaporates efficiently, and the hydrogen peroxide is removed from the object. However, after a certain time has passed since the start of the reduced pressure drying step SB11, the amount of evaporated hydrogen peroxide decreases.

[0052] Fig. 4 is a diagram showing the change in the amount of hydrogen peroxide remaining on a 96-well plate due to the reduced pressure drying step SB11. As shown in Fig. 4, the hydrogen peroxide remaining on a sterilized 96-well plate decreases quadratically due to the reduced pressure drying step, but it was found that the removal effect is limited to a concentration of about 1.0 μg / mL at the time of filling the medium. Therefore, in this embodiment, the control device 61 ends the reduced pressure drying step SB11 at a point when about 24 hours have passed from the start of the reduced pressure drying step SB11. The cause of the decrease in the amount of evaporated hydrogen peroxide may be a high concentration of hydrogen peroxide remaining in the object, or hydrogen peroxide binding to the object and thus becoming difficult to evaporate.

[0053] After the reduced pressure drying step SB11 is completed, a water vapor supplying step SB12 is performed. In the water vapor supplying step SB12, the control device 61 controls the steam cleaning unit 30 so that water vapor is supplied to the internal space of the chamber 11 while the internal space of the chamber 11 is depressurized to about 10 Pa.

[0054] In the water vapor supplying step SB12, water vapor is supplied to the internal space of the chamber 11.

[0055] The amount of water vapor supplied to the internal space of the chamber 11 is small. As an example, the amount of water vapor supplied to the internal space of the chamber 11 is about 10 cc. If a large amount of water vapor is supplied to the internal space of the chamber 11, the vacuum pump 41 of the decompression unit 40 may suck in a large amount of water vapor in the decompression step SB15 performed after the water vapor supply step SB12. In this embodiment, the amount of water vapor supplied to the internal space of the chamber 11 is determined in advance. The amount of water vapor supplied to the internal space of the chamber 11 is determined so as not to affect the vacuum pump 41 and to remove hydrogen peroxide from the target object.

[0056] In addition, the pressure in the internal space of the chamber 11 increases to about 20 Pa by supplying a small amount of water vapor to the internal space of the chamber 11.

[0057] After the water vapor supply step SB12 is completed, an air supply step SB13 is performed. In the air supply step SB13, the control device 61 controls the pressure recovery unit 50 so that air is supplied to the internal space of the chamber 11. As described above, the pressure recovery unit 50 has a filter 51 such as a HEPA filter. Clean air (air) that has passed through the filter 51 is supplied to the internal space of the chamber 11. The pressure in the internal space of the chamber 11 increases as air (air) is supplied to the internal space of the chamber 11. The control device 61 may increase the pressure in the internal space of the chamber 11 to atmospheric pressure or to a pressure lower than atmospheric pressure.

[0058] In this embodiment, in the air supplying step SB13, the pressure in the internal space of the chamber 11 increases to a pressure (about 90,000 Pa) lower than atmospheric pressure, so that the supplied water vapor is diffused over the entire surface of the object.

[0059] After the atmosphere supply step SB13 is completed, an atmosphere holding step SB14 is performed in which the pressure in the internal space of the chamber 11 is maintained at approximately 90,000 Pa. This causes the hydrogen peroxide remaining on the object to dissolve in the moisture (supplied water vapor) adhering to the entire surface of the object.

[0060] After the atmospheric holding step SB14 is completed, the depressurization step SB15 is carried out. In the depressurization step SB15, the control device 61 controls the depressurization unit 40 so that the internal space of the chamber 11 in which the object is accommodated is depressurized. In the depressurization step SB15, the control device 61 depressurizes the internal space of the chamber 11 so that the pressure in the internal space of the chamber 11 becomes approximately 35 Pa (first pressure). In the depressurization step SB15, the control device 61 controls the heating unit 13 so that the pressure becomes equal to the temperature of the internal space of the chamber 11. As an example, the depressurization temperature is approximately 50°C. As the chamber 11 is depressurized, hydrogen peroxide remaining on the surface of the object is removed together with moisture and discharged to the external space.

[0061] In the depressurization step SB15, the pressure in the internal space of chamber 11 is adjusted to about 35 Pa, and the temperature is adjusted to about 50° C., and this state is maintained for a time period (first time period) of 1 minute to 10 minutes inclusive. As an example, the state in which the pressure in the internal space of chamber 11 is adjusted to about 35 Pa, and the temperature is adjusted to about 50° C. is continued for about 3 minutes.

[0062] After the pressure reduction step SB15 is completed, the water vapor supplying step SB16 is carried out. The water vapor supplying step SB16 is similar to the water vapor supplying step SB12 described above.

[0063] After the water vapor supplying step SB16 is completed, the atmosphere supplying step SB17 and the atmosphere holding step SB 18 are performed. The atmosphere supplying step SB17 is similar to the atmosphere supplying step SB13 described above, and the atmosphere holding step SB18 is similar to the atmosphere holding step SB14 described above.

[0064] The pulse process including the depressurization step SB15, the water vapor supply step SB16, the atmosphere supply step SB17, and the atmosphere holding step SB18 is performed multiple times. In the following description, the number of times the pulse process including the depressurization step SB15, the water vapor supply step SB16, the atmosphere supply step SB17, and the atmosphere holding step SB18 is performed is appropriately referred to as the pulse number.

[0065] The number of pulses is a predetermined value. The user may operate the input device 62 to input the number of pulses to the control device 61. The number of pulses may be arbitrarily determined by the user. The control device 61 determines whether the number of times the pulse process has been performed has reached the number of pulses (step SB19).

[0066] In step SB19, if it is determined that the number of pulses has not been reached (step SB19: No), the control device 61 repeats the processes from step SB15 to step SB18 until the number of pulse processes reaches the number of pulses.

[0067] If it is determined in step SB19 that the number of pulses has been reached (step SB19: Yes), the control device 61 ends the removal process SB.

[0068] <Effects> As described above, in this embodiment, the process SB for removing hydrogen peroxide remaining in the target object includes a depressurization process SB15 for depressurizing the internal space of the chamber 11 in which the target object is housed, a water vapor supply process SB16 for supplying water vapor to the internal space of the chamber 11 while the internal space of the chamber 11 is depressurized, and an air supply process SB17 for supplying air to the internal space of the chamber 11 after water vapor has been supplied to the internal space of the chamber 11.

[0069] According to the embodiment, since the water vapor supplying step SB16 is performed, hydrogen peroxide remaining on the object is dissolved in the water vapor and is peeled off from the object. As a result, hydrogen peroxide remaining on the object is sufficiently removed.

[0070] For example, in the field of regenerative medicine, cell culture is performed in a cell culture isolator. In the cell culture, parts such as petri dishes and well plates are used. The parts used for cell culture are sterilized in a sterilization device 100 and then used in the cell culture isolator. If hydrogen peroxide remains in the parts, cell culture cannot be performed properly. According to this embodiment, the amount of hydrogen peroxide remaining in the object is reduced to a concentration of less than 0.5 μg / mL when the medium is filled, and cell culture can be performed properly.

[0071] FIG. 5 is a diagram for explaining the effect of the removal process according to the present embodiment. FIG. 5a is a diagram showing the survival rate after 7 days when human iPS cells are cultured on a 96-well plate that has been subjected to the removal process after the sterilization process according to the present embodiment. In FIG. 5a, Normal is a negative control, and A, C, E, and G indicate plate rows. As shown in FIG. 5a, the influence of residual hydrogen peroxide was not observed, including the A row and G row on the outer side of the plate where hydrogen peroxide is likely to remain, and the survival rate was equivalent to that of the negative control group. FIG. 5b is a diagram showing the number of cells after 1 day, 3 days, and 5 days when marmoset ES cells are cultured on a 6-well plate. In FIG. 5b, Control is a negative control, and Sample is a test group. As shown in FIG. 5b, no significant difference was observed between the negative control and the test group regardless of the culture period, and no influence of residual hydrogen peroxide was observed.

[0072] In this embodiment, the pulse process including the pressure reduction process SB15, the water vapor supply process SB16, and the air supply process SB17 is performed multiple times. By performing the pulse process multiple times, hydrogen peroxide remaining in the target object is sufficiently removed.

[0073] In this embodiment, the internal space of chamber 11 is set to a first pressure (about 35 Pa) by the depressurization step SB15. Before the pulse step (depressurization step SB15), a depressurization drying step SB11 is performed in which the internal space of chamber 11 is depressurized to a second pressure (about 10 Pa) lower than the first pressure. This allows hydrogen peroxide remaining in the object to evaporate efficiently, thereby removing hydrogen peroxide from the object.

[0074] In this embodiment, in the depressurization step SB15, the internal space of chamber 11 is maintained at a first pressure (about 35 Pa) for a first time (e.g., 3 minutes). In the reduced-pressure drying step SB11, the internal space of chamber 11 is maintained at a second pressure (about 10 Pa) for a second time (e.g., 24 hours) that is longer than the first time. As a result, hydrogen peroxide remaining in the object is efficiently evaporated in the reduced-pressure drying step SB11, and hydrogen peroxide is removed from the object.

[0075] In this embodiment, before the reduced pressure drying process SB11, a sterilization process (sterilization process SA) is performed in which the object is sterilized with hydrogen peroxide in the internal space of the chamber 11. In this way, the sterilization process SA and the removal process SB are performed consecutively in one sterilization apparatus 100.

[0076] [Second embodiment] A second embodiment will be described below. In the following description, the same or equivalent components as those in the above-described embodiment are denoted by the same reference numerals, and the description of those components will be simplified or omitted.

[0077] 6 is a flowchart showing the removal process SB according to this embodiment. In this embodiment, the removal process SB includes a reduced pressure drying process SB21, an atmosphere supplying process SB22, a reduced pressure process SB23, a water vapor supplying process SB24, and an atmosphere supplying process SB25.

[0078] After the sterilization process is completed, a reduced pressure drying step SB21 is performed with the object housed in the chamber 11. In the reduced pressure drying step SB21, the control device 61 controls the decompression unit 40 so that the internal space of the chamber 11 in which the object is housed is decompressed. In the reduced pressure drying step SB21, the control device 61 decompresses the internal space of the chamber 11 so that the pressure in the internal space of the chamber 11 becomes approximately 10 Pa (second pressure). In the reduced pressure drying step SB21, the control device 61 controls the heating unit 13 so that the temperature of the internal space of the chamber 11 becomes a reduced pressure drying temperature that is higher than the sterilization temperature. As an example, the reduced pressure drying temperature is approximately 80°C.

[0079] In the reduced pressure drying step SB21, the pressure in the internal space of the chamber 11 is adjusted to about 10 Pa, and the temperature is adjusted to about 80° C., and this state is maintained for about 24 hours (second time).

[0080] In the reduced pressure drying step SB21, when the internal space of the chamber 11 is decompressed, hydrogen peroxide remaining in the object evaporates efficiently, and hydrogen peroxide is removed from the object. However, the amount of evaporated hydrogen peroxide decreases after a certain time has passed since the start of the reduced pressure drying step SB21. Therefore, in this embodiment, the control device 61 ends the reduced pressure drying step SB21 about 24 hours after the start of the reduced pressure drying step SB21. The decrease in the amount of evaporated hydrogen peroxide may be due to a high concentration of hydrogen peroxide remaining in the object or hydrogen peroxide binding to the object and becoming difficult to evaporate.

[0081] After the reduced pressure drying step SB21 is completed, the air supplying step SB22 is performed. In the air supplying step SB22, the control device 61 controls the pressure recovery unit 50 so that air is supplied to the internal space of the chamber 11. As described above, the pressure recovery unit 50 has a filter 51 such as a HEPA filter. Clean air (air) that has passed through the filter 51 is supplied to the internal space of the chamber 11. The pressure of the internal space of the chamber 11 increases as the air (air) is supplied to the internal space of the chamber 11. The control device 61 may increase the pressure of the internal space of the chamber 11 to atmospheric pressure or to a pressure lower than atmospheric pressure.

[0082] In this embodiment, in the air supplying step SB22, the pressure in the internal space of the chamber 11 increases to a pressure (about 90,000 Pa) lower than atmospheric pressure, so that hydrogen peroxide remaining in the object is discharged to the external space of the chamber 11 together with the air.

[0083] After the air supply step SB22 is completed, a depressurization step SB23 for depressurizing the internal space of the chamber 11 is carried out.

[0084] After the depressurization step SB23 is completed, a water vapor supply step SB24 is performed to supply water vapor to the internal space of the chamber 11. When water vapor is supplied to the internal space of the chamber 11 in the water vapor supply step SB24, hydrogen peroxide remaining in the object is dissolved in the water vapor. The hydrogen peroxide is peeled off from the object by the water vapor. As a result, the hydrogen peroxide is removed from the object.

[0085] After the water vapor supplying step SB24 is completed, the atmosphere supplying step SB25 is performed. In the atmosphere supplying step SB25, the control device 61 controls the pressure recovery unit 50 so that the atmosphere is supplied to the internal space of the chamber 11.

[0086] The pulse process including the pressure reduction process SB23, the water vapor supply process SB24, and the air supply process SB25 is performed multiple times. The pulse number indicating the number of times the pulse process is performed is a predetermined value. The user may operate the input device 62 to input the pulse number to the control device 61. The pulse number may be arbitrarily determined by the user. The control device 61 determines whether the number of times the pulse process has been performed has reached the pulse number (step SB26).

[0087] In step SB26, if it is determined that the number of pulses has not been reached (step SB26: No), the control device 61 repeats the processes from step SB23 to step SB25 until the number of pulse processes reaches the number of pulses.

[0088] If it is determined in step SB26 that the number of pulses has been reached (step SB26: Yes), the control device 61 ends the removal process SB. [Explanation of symbols]

[0089] 10...chamber unit, 11...chamber, 12...door, 13...heating unit, 14...pressure sensor, 15...temperature sensor, 16...injection line, 17...injection line, 18...injection line, 19...injection line, 20...hydrogen peroxide supply unit, 21...bottle, 22...extraction line, 23...tube pump, 24...storage unit, 25...filter, 26...evaporator, 27...supply line, 28...valve, 29...heater, 30...steam cleaning unit, 31...bottle, 32...extraction line, 33...tube pump, 34...storage unit, 35...filter, 36...evaporator, 37...supply line, 38...valve, 39...heater, 40...pressure reduction unit , 41...vacuum pump, 42...first catalyst tank, 43...second catalyst tank, 44...first heater, 45...second heater, 46...exhaust line, 50...recovery unit, 51...filter, 52...introduction line, 60...control unit, 61...control device, 62...input device, 71...valve, 72...valve, 73...valve, 74...valve, 77...valve, 78...valve, 100...sterilization apparatus, SA...sterilization treatment, SB...removal treatment, SB11...reduced pressure drying process, SB12...water vapor supply process, SB13...atmosphere supply process, SB14...atmosphere holding process, SB15...reduced pressure process, SB16...water vapor supply process, SB17...atmosphere supply process, SB18...atmosphere holding process.

Claims

1. A method for removing hydrogen peroxide remaining in an object, comprising the steps of: a decompression step of decompressing an internal space of a chamber in which the object is accommodated; a water vapor supplying step of supplying water vapor into the internal space while the internal space is in a decompressed state; and an air supplying step of supplying clean air passed through a HEPA filter to the internal space after water vapor is supplied to the internal space. How to remove hydrogen peroxide.

2. A pulse process including the pressure reduction process, the water vapor supply process, and the air supply process is performed multiple times. The method for removing hydrogen peroxide according to claim 1.

3. The pressure reduction step brings the internal space to a first pressure, Prior to the pulse step, a reduced pressure drying step is performed in which the internal space is reduced in pressure to a second pressure lower than the first pressure. The method for removing hydrogen peroxide according to claim 2.

4. In the depressurization step, the state in which the internal space is at the first pressure is maintained for a first time, In the reduced pressure drying step, the state in which the internal space is at the second pressure is maintained for a second time that is longer than the first time. The method for removing hydrogen peroxide according to claim 3.

5. A sterilization step is performed in which the object is sterilized by the hydrogen peroxide in the internal space before the reduced pressure drying step. The method for removing hydrogen peroxide according to claim 3.

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