Sterilization device

Abstract

To improve a sterilization performance of a sterilizer.SOLUTION: A sterilizer 1 includes a sterilization container 11, a disinfectant supply part 12, a plurality of heating parts 43, and a control unit 3. The sterilization container 11 has a sterilization chamber 11a inside thereof for housing an object 100 to be sterilized. The disinfectant supply part 12 reduces a pressure inside the sterilization chamber 11a so as to vaporize a liquid disinfectant, and supplies the vaporized disinfectant to a sterilization chamber 11a. The heating parts 43 are housed in the sterilization chamber 11a. The plurality of heating parts 43 heat the object 100 to be sterilized housed in the sterilization chamber 11a. The control unit 3 controls the plurality of heating parts 43 independently.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] SUMMARY OF THE INVENTION The embodiments disclosed herein relate to a sterilization device. [Background technology]

[0002] Conventionally, a sterilization device is known that reduces the pressure in a sterilization chamber in a sterilization cabinet, vaporizes a sterilizing agent such as an aqueous hydrogen peroxide solution while sucking it into the sterilization chamber, and sterilizes objects to be sterilized contained in the sterilization chamber with the vaporized sterilizing agent. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-007422 Summary of the Invention [Problem to be solved by the invention]

[0004] It would be beneficial for this type of sterilizer to be able to further improve its sterilization performance. One of the problems that the embodiments disclosed in this specification etc. aim to solve is to improve the sterilization performance of the sterilizer. However, the problems solved by the embodiments disclosed in this specification etc. are not limited to the above problem. Problems corresponding to the effects of each configuration shown in the embodiments described below can also be positioned as other problems solved by the embodiments disclosed in this specification etc. [Means for solving the problem]

[0005] A sterilization apparatus according to an embodiment of the present invention comprises a sterilization cabinet having a sterilization chamber therein for accommodating objects to be sterilized, a sterilant supply unit that vaporizes a liquid sterilant by reducing the pressure inside the sterilization chamber and supplies the vaporized sterilant to the sterilization chamber, a plurality of heating units that heat the objects to be sterilized accommodated in the sterilization chamber, and a control device that independently controls each of the plurality of heating units. [Brief explanation of the drawings]

[0006] [Figure 1] FIG. 1 is a diagram illustrating an example of the configuration of a sterilization device according to an embodiment. [Figure 2] FIG. 2 is a front view illustrating an example of a part of the sterilization chamber in the sterilization apparatus of the embodiment, showing the part other than the door of the sterilization chamber. [Figure 3] FIG. 3 is a plan view exemplarily showing the main shelf of the sterilization apparatus of the embodiment. [Figure 4] FIG. 4 is a plan view exemplarily showing a part of the heating and vaporizing unit of the sterilizer of the embodiment, showing the part other than the upper wall. [Figure 5] FIG. 5 is a cross-sectional view exemplarily showing a part of a cross section taken along line VV in FIG. [Figure 6] FIG. 6 is a cross-sectional view exemplarily showing a part of a cross section taken along line VI-VI in FIG. [Figure 7] FIG. 7 is a cross-sectional view exemplarily showing a part of a cross section taken along line VII-VII in FIG. [Figure 8] FIG. 8 is a plan view exemplarily showing a part of the heating and vaporizing unit of a modified example of the embodiment, showing the part other than the upper wall. DETAILED DESCRIPTION OF THE INVENTION

[0007] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings, but the present invention is not limited to these embodiments.

[0008] Furthermore, the drawings are schematic, and the dimensional relationships and ratios of elements may differ from reality. Furthermore, the drawings may contain parts with different dimensional relationships and ratios. Furthermore, in this specification, ordinal numbers are used only to distinguish between parts, members, locations, positions, directions, etc., and do not indicate order or priority.

[0009] FIG. 1 is a diagram showing an example of the configuration of a sterilization apparatus 1 of an embodiment. As shown in FIG. 1, sterilization apparatus 1 comprises a sterilization treatment unit 2 and a control unit 3. The sterilization treatment unit 2 vaporizes a liquid sterilant and sterilizes the object to be sterilized 100 with the vaporized sterilant. In other words, the sterilization treatment unit 2 can kill bacteria. In other words, the sterilization treatment unit 2 sterilizes. In other words, the sterilization treatment unit 2 can reduce bacteria. The liquid sterilant is, for example, an aqueous hydrogen peroxide solution. The object to be sterilized 100 is, for example, a medical device. The medical device may be one with an internal cavity, such as an endoscope, or one without an internal cavity. The object to be sterilized 100 may be an object other than a medical device. The control unit 3 controls the sterilization treatment unit 2. The sterilization apparatus 1 is also called a sterilization apparatus.

[0010] The sterilization treatment section (sterilization treatment section) 2 comprises a sterilization cabinet (sterilization cabinet) 11 and a sterilizing agent supply section (sterilant supply section) 12. Inside the sterilization cabinet 11 is provided a sterilization chamber (sterilization chamber) 11a that houses an object to be sterilized (object to be sterilized) 100, and the sterilizing agent supply section 12 supplies a sterilizing agent (sterilant) to the sterilization chamber 11a. The sterilization chamber 11a is also referred to as a chamber.

[0011] In this embodiment, for convenience, three mutually orthogonal directions are defined. The X direction corresponds to the rear of the front-to-rear direction (depth direction) of the sterilization chamber 11, the Y direction corresponds to the width direction of the sterilization chamber 11, and the Z direction corresponds to the upper side of the up-down direction (height direction) of the sterilization chamber 11. Hereinafter, the width direction of the sterilization chamber 11 will also be referred to as the left-to-right direction.

[0012] Sterilant supply section 12 includes cartridge 31, liquid phase pump 32, concentrator 33, solenoid valve 34, distributor 35, heating and vaporization unit 36, vacuum pump 37, solenoid valve 38, and vacuum gauge 39. Cartridge 31, liquid phase pump 32, concentrator 33, solenoid valve 34, distributor 35, and heating and vaporization unit 36 ​​form a fluid circuit. Heating and vaporization unit 36 ​​is an example of a unit.

[0013] The vacuum pump 37 sucks gas from the sterilization cabinet 11, i.e., the sterilization chamber 11a, the heating and vaporization unit 36, and the distributor 35, reducing the pressure in each space to create a vacuum state (a state in which the space is filled with gas at negative pressure, which is a pressure lower than atmospheric pressure). A vacuum state is also called a negative pressure state.

[0014] Cartridge 31 contains a liquid disinfectant (concentrate). Liquid phase pump 32 sucks the liquid disinfectant from cartridge 31 and discharges, i.e., supplies, the sucked liquid disinfectant to concentrator 33. Liquid phase pump 32 is a tube pump that can measure the amount of disinfectant sucked in and discharged.

[0015] Concentrator 33 heats the liquid sterilant to concentrate it. Specifically, concentrator 33 uses heat to vaporize the water in the hydrogen peroxide solution, thereby increasing the concentration of hydrogen peroxide in the hydrogen peroxide solution.

[0016] The solenoid valve 34 is provided between the concentrator 33 and the sterilization chamber 11a. When the solenoid valve 34 opens, the sterilizing agent from the concentrator 33 is supplied to the sterilization chamber 11a if the sterilization chamber 11a is under negative pressure.

[0017] Distributor 35 is installed between concentrator 33 and sterilization chamber 11a. Distributor 35 divides the liquid sterilant that flows in from solenoid valve 34 by negative pressure into four parts according to Pascal's law, and distributes equal amounts to four vaporizers 42, which will be described later.

[0018] The four vaporizers 42 vaporize the liquid sterilant and supply the gaseous sterilant into the sterilization chamber 11a.

[0019] The solenoid valve 38 can be switched between an open state, which connects the inside and outside of the sterilization chamber 11a, and a closed state, which blocks communication between the inside and outside of the sterilization chamber 11a. When the solenoid valve 38 is in the open state, the sterilization chamber 11a returns from a reduced pressure state to atmospheric pressure. The vacuum gauge 39 measures the degree of vacuum in the sterilization chamber 11a.

[0020] Figure 2 is a front view showing an example of a part of the sterilization cabinet 11 in the sterilization apparatus 1 of the embodiment, showing the part of the sterilization cabinet 11 other than the door 22. As shown in Figures 1 and 2, a sterilization chamber 11a is provided inside the sterilization cabinet 11. An object to be sterilized 100 (Figure 1) is accommodated in the sterilization chamber 11a.

[0021] The sterilization chamber 11 has a substantially rectangular box shape with the longitudinal direction being the front-to-rear direction and the transverse direction being the width direction. The sterilization chamber 11 has a main body 21 and a door 22. The sterilization chamber 11 is also referred to as a housing.

[0022] The main body 21 has an upper wall 21a, a lower wall 21b, a right wall 21c, a left wall 21d, and a rear wall 21e. The upper wall 21a and the lower wall 21b extend in a direction perpendicular to the up-down direction and are parallel to each other with a gap in the up-down direction. The right wall 21c and the left wall 21d extend in a direction perpendicular to the width direction and are parallel to each other with a gap in the width direction. The rear wall 21e extends in a direction perpendicular to the front-rear direction and connects the rear ends of the upper wall 21a, the lower wall 21b, the right wall 21c, and the left wall 21d.

[0023] A sterilization chamber 11a is provided inside the main body 21. The sterilization chamber 11a is surrounded by an upper wall 21a, a lower wall 21b, a right wall 21c, a left wall 21d, and a rear wall 21e.

[0024] The door 22 is rotatably supported at the front end of the upper wall 21a, the lower wall 21b, the right wall 21c, or the left wall 21d, and can be opened and closed relative to the main body 21. The door 22 is the front wall of the sterilization cabinet 11. When closed, the door 22 extends in a direction perpendicular to the front-to-rear direction and overlaps with the front end of the upper wall 21a, the lower wall 21b, the right wall 21c, and the left wall 21d, thereby closing the sterilization chamber 11a. When the door 22 is opened, the sterilization chamber 11a is opened forward. The rear wall 21e may be configured as a door that can be opened and closed like the door 22. That is, both the door 22 and the rear wall 21e may be openable and closable. The door 22 is an example of a wall.

[0025] The upper wall 21a, lower wall 21b, right wall 21c, left wall 21d, rear wall 21e, and door 22 surround the sterilization chamber 11a. In other words, the upper wall 21a, lower wall 21b, right wall 21c, left wall 21d, rear wall 21e, and door 22 form the sterilization chamber 11a. The upper wall 21a, lower wall 21b, right wall 21c, left wall 21d, rear wall 21e, and door 22 are made of, for example, stainless steel plates several millimeters thick. The sterilization chamber 11 is rigid and has a relatively high specific heat.

[0026] As shown in Figure 1, an external heater 25 is superimposed on the outer surfaces of the door 22, upper wall 21a, lower wall 21b, right wall 21c, left wall 21d, and rear wall 21e. Note that Figure 1 only shows a portion of the external heater 25. The external heater 25 heats the interior of the sterilization cabinet 11, i.e., the sterilization chamber 11a, from outside the sterilization cabinet 11. The external heater 25 has a heat source such as a sheet heater. Hereinafter, the temperature of the sterilization chamber 11a during sterilization (sterilization) may be referred to as the sterilization temperature (sterilization temperature). The external heater 25 is an example of an external heating unit.

[0027] As shown in Figure 2, the sterilization chamber 11a accommodates two main shelves 23, two sub-shelves 24, and two heating and vaporizing units 36. The main shelf 23 is also referred to as a first shelf, and the sub-shelf 24 is also referred to as a second shelf. The main shelf 23 is an example of a shelf.

[0028] The two main shelves 23 and the two sub-shelves 24 are arranged vertically with a gap between them. The lower of the two main shelves 23 is arranged above the lower wall 21b, the lower of the two sub-shelves 24 is arranged above the lower main shelf 23, the upper of the two main shelves 23 is arranged above the lower sub-shelf 24, and the upper of the two sub-shelves 24 is arranged above the upper main shelf 23. Each main shelf 23 and sub-shelf 24 is detachably supported by supports 21f, 21g provided on the right wall 21c and the left wall 21d. The two main shelves 23 and the two sub-shelves 24 are slidable in the front-to-rear direction relative to the sterilization cabinet 11. Objects to be sterilized 100 can be placed on each of the two main shelves 23 and the two sub-shelves 24.

[0029] FIG. 3 is a plan view illustrating an example of the main shelf 23 of the sterilization apparatus 1 of the embodiment. As shown in FIG. 3, the main shelf 23 is in a mesh shape with multiple openings 23c. Specifically, the main shelf 23 has multiple rod-shaped first members 23a and multiple rod-shaped second members 23b. The multiple first members 23a extend in the front-rear direction and are spaced apart from one another in the width direction. The multiple second members 23b extend in the width direction and are spaced apart from one another in the front-rear direction. The multiple first members 23a and the multiple second members 23b are connected to one another. A net 26 is placed on the underside of the main shelf 23. For example, the net 26 is welded to the main shelf 23 and integrated with the main shelf 23. The specific heat of the net 26 is lower than that of the main shelf 23. The net 26 has multiple openings. Note that the net 26 does not necessarily have to be provided.

[0030] As shown in FIG. 2 , the two heating / vaporizing units 36 are disposed below the two main shelves 23, respectively. Specifically, the two heating / vaporizing units 36 are disposed directly below the two main shelves 23, respectively. "Directly below" means that the vertical distance between the upper end of the heating section 43 included in the heating / vaporizing unit 36 ​​and the upper end of the main shelf 23 is less than half the vertical height of the space on the main shelf 23 that can accommodate the objects to be sterilized 100 (hereinafter also referred to as "on-shelf storage space"). In this embodiment, the lower end of the on-shelf storage space on the main shelf 23 coincides with the upper end of the main shelf 23, and the upper end of the on-shelf storage space coincides with the lower end of the sub-shelf 24 above the main shelf 23 that is adjacent to the main shelf 23 in the vertical direction. Note that the vertical distance between the upper end of the heating section 43 and the upper end of the main shelf 23 may be less than ¼ or 1 / 10 of the vertical height of the on-shelf storage space on the main shelf 23.

[0031] The upper of the two heating / vaporization units 36 is detachably supported by supports 21h provided on the right wall 21c and the left wall 21d, and the lower of the two heating / vaporization units 36 is detachably supported by the bottom wall 21bc.

[0032] Fig. 4 is a plan view illustratively showing a part of the heating and vaporization unit 36 ​​of the sterilizer 1 of the embodiment, showing the part other than the upper wall 41a. Fig. 5 is a cross-sectional view illustratively showing a part of a cross section taken along line VV in Fig. 4. Fig. 6 is a cross-sectional view illustratively showing a part of a cross section taken along line VI-VI in Fig. 4.

[0033] As shown in FIGS. 1, 4, and 5, the heating / vaporizing unit 36 ​​has a case 41, two vaporizers 42, a heating section 43, and a temperature sensor 44.

[0034] The case 41 has an upper wall 41a (FIGS. 4 and 5), a lower wall 41b, a right wall 41c (FIG. 4), a left wall 41d (FIG. 4), a rear wall 41e (FIG. 4), and a front wall 41f (FIG. 4). The case 41 is made of, for example, aluminum.

[0035] The upper wall 41a and the lower wall 41b both extend in a direction perpendicular to the up-down direction and are provided parallel to each other with a gap in the up-down direction. The upper wall 41a has an opening 41aa (FIGS. 5 and 6). The opening 41aa is a through-hole that penetrates the upper wall 41a in the up-down direction. The right wall 41c and the left wall 41d both extend in a direction perpendicular to the width direction and are provided parallel to each other with a gap in the width direction. The rear wall 41e and the front wall 41f extend in a direction perpendicular to the front-rear direction and are provided parallel to each other with a gap in the front-rear direction.

[0036] As shown in Fig. 4, two vaporizers 42 are arranged in case 41 at a distance from each other in the front-to-rear direction, which is a direction intersecting the up-and-down direction. Each vaporizer 42 has a pair of plates 45, 46. Therefore, two sets 47 of two plates 45, 46 are provided, and these sets 47 are arranged in case 41 at a distance from each other in the front-to-rear direction. Note that the number of sets 47 is not limited to the above. For example, there may be one set 47, or three or more sets 47.

[0037] As shown in FIG. 1, two plates 45 and 46 are disposed below the main shelf 23 in the sterilization chamber 11a. As shown in FIGS. 4 to 6, the plates 45 and 46 are flat. The two plates 45 and 46 extend in a direction perpendicular to the vertical direction and are parallel to each other with a gap between them in the vertical direction. The two plates 45 and 46 are also referred to as parallel plates. The thickness of the two plates 45 and 46 is, for example, about 3 mm, but is not limited to this. The plate 46 is disposed below the plate 45. The plate 45 is fixed to the upper surface of the upper wall 41a by fasteners 51 such as screws, with the opening 41aa covering part of the opening 41aa in the upper wall 41a. In other words, the plate 45 is supported by the upper wall 41a. The plate 46 is disposed between the upper wall 41a and the lower wall 41b and fixed to the inner surfaces of the upper wall 41a and the lower wall 41b by fasteners 51. That is, the plate 46 is supported by the upper wall 41a and the lower wall 41b. The plate 46 has a facing portion 46a (FIGS. 5 and 6) and a protruding portion 46b. The facing portion 46a faces the plate 45 in the up-down direction. The protruding portion 46b is connected to the facing portion 46a and protrudes from the plate 45 in the width direction that intersects with the up-down direction. A plate 50 is provided between the plate 46 and the lower wall 41b. The plate 50 is made of, for example, aluminum.

[0038] 5 and 6, vaporizer 42 is provided with supply port 42b and outlet 42c (FIG. 6). Supply port 42b is provided in the approximate center of plate 46. That is, supply port 42b is provided on one of two plates 45 and 46, inside outer edge 46c of plate 46. Liquid sterilant is supplied to supply port 42b from distributor 35 via tube 48. Supply port 42b supplies the liquid sterilant to gap 42a between two plates 45 and 46. Gap 42a is a passage for the sterilant. Gap 42a is included in opening 41aa of upper wall 41a. Tube 48 is made of, for example, stainless steel. Tube 48 is configured, for example, by connecting a stainless steel tube and a heat-resistant silicone tube. The silicone tube is provided in a portion adjacent to heating unit 43. Tube 48 is also referred to as piping.

[0039] The outlet 42c is spaced from the supply port 42b in the width direction, which intersects with the vertical direction. The outlet 42c is formed by an outer edge portion 42d of the two plates 45, 46 that is open to the outside in the gap 42a between the two plates 45, 46. The outlet 42c is also connected to the protruding portion 46b. The sterilant between the two plates 45, 46 flows out of the gap 42a between the two plates 45, 46 from the outlet 42c.

[0040] As shown in FIG. 1, the heating section 43 is disposed below the main shelf 23 in the sterilization chamber 11a. Also, as shown in FIG. 4, the heating section 43 is provided around the two plates 45, 46 of each of the two sets 47. The heating section 43 is a single sheathed heater formed by bending. The sheathed heater includes, for example, a stainless steel pipe forming the outer periphery. The sheathed heater has an outer diameter of, for example, 6 mm and a rated power of approximately 1500 W, but is not limited thereto. The heating section 43 has a relatively low specific heat. The heating section 43 has a plurality of first extensions 43a, a plurality of second extensions 43b, a plurality of third extensions 43c, and one fourth extension 43d. The first extensions 43a all extend widthwise and are arranged parallel to each other with a gap in the front-to-rear direction. The vaporizer 42 is disposed between the two first extensions 43a. The multiple second extending portions 43b all extend in the front-rear direction and are spaced apart in the front-rear direction. The second extending portion 43b connects the right ends of two first extending portions 43a that are adjacent in the front-rear direction. The multiple third extending portions 43c all extend in the front-rear direction and are spaced apart in the front-rear direction. The third extending portion 43c connects the left ends of two first extending portions 43a that are adjacent in the front-rear direction. The second extending portions 43b and the third extending portions 43c are arranged alternately. The fourth extending portion 43d extends rearward from the left end of the first extending portion 43a that is located furthest forward among the multiple first extending portions 43a.

[0041] As shown in FIG. 4 , temperature sensor 44 is provided in case 41 and positioned between two vaporizers 42. Temperature sensor 44 is, for example, a thermocouple. Temperature sensor 44 is thermally connected to second extension portion 43b of heating portion 43 via heat transfer member 52. Temperature sensor 44 measures the temperature of heating portion 43. It can also be said that temperature sensor 44 measures the temperature of heating / vaporization unit 36.

[0042] Fig. 7 is a cross-sectional view exemplarily illustrating a portion of a cross section taken along line VII-VII in Fig. 4. As shown in Fig. 7, heat transfer member 52 has contact portions 52a and 52b. Contact portion 52a is a concave surface. Heating portion 43 is placed in contact portion 52a, and contact portion 52a is in contact with heating portion 43. Contact portion 52b is a concave surface. Temperature sensor 44 is placed in contact portion 52b, and contact portion 52b is in contact with temperature sensor 44. Heat transfer member 52 is made of, for example, aluminum.

[0043] Here, the specific heat of the heating section 43, the two plates 45, 46, and the case 41 of the heating / vaporizing unit 36 ​​is lower than the specific heat of each wall (upper wall 21a, lower wall 21b, right wall 21c, left wall 21d, rear wall 21e, door 22) of the sterilizing chamber 11. In other words, the specific heat of the heating / vaporizing unit 36 ​​as a whole is lower than that of the sterilizing chamber 11.

[0044] The control device 3 shown in FIG. 1 has a CPU (Central Processing Unit), ROM (Read Only Memory), and RAM (Random Access Memory). In other words, the control device 3 is a computer. The CPU reads and executes programs stored in the ROM, etc. The RAM temporarily stores various data used when the CPU executes the programs and performs various arithmetic processing. The control device 3 also controls the outer heater 25, the liquid phase pump 32, the concentrator 33, the solenoid valve 34, the heating unit 43, the vacuum pump 37, the solenoid valve 38, etc. The control device 3 is also connected to a vacuum gauge 39, a temperature sensor 44, etc.

[0045] The control device 3 controls the outer heater 25 based on the measurement value of an inside temperature sensor provided at a predetermined position (for example, on the upper surface inside the sterilization cabinet 11) so that the center of the sterilization cabinet 11, i.e., the center of the sterilization chamber 11a, reaches a specified target temperature (hereinafter also referred to as the inside temperature setting). The inside temperature setting may be, for example, 40°C to 65°C, 45°C to 60°C, or 65°C or higher, or may be any other temperature. The location measured by the inside temperature sensor is a location that is less susceptible to the heat generated by the heating unit 43.

[0046] The control device 3 controls each of the multiple heating units 43 independently. In other words, the control device 3 controls each of the multiple heating units 43 individually. The control device 3 controls the heating units 43 based on the measurement value of the temperature sensor 44 so that the temperature of the heating units 43 reaches a specified target temperature (hereinafter also referred to as the heating set temperature). This type of control can be performed, for example, to bring the temperature of the object to be sterilized 100 to the heating set temperature after a predetermined time has elapsed. The heating set temperature is, for example, higher than the set temperature inside the cabinet. The above control is, for example, PID (Proportional Integral Differential) control, in which the measurement value of the temperature sensor 44 is used as an input value. The heating set temperature is also referred to as the control target temperature.

[0047] The heating temperature setting of the heating part 43 differs for each heating / vaporization unit 36. The heating temperature setting can be determined, for example, experimentally, taking into consideration various circumstances. For example, the heating temperature setting is affected by the position where the heating part 43 is arranged, the distance of the heating part 43 from the inner surface of the upper wall 21a or the inner surface of the lower wall 21b of the sterilization chamber 11, the positional relationship with other heating parts 43, etc.

[0048] For example, the heating temperature setting of the heating section 43 of the lower heating / vaporizing unit 36 ​​may be set lower than the heating temperature setting of the upper heating / vaporizing unit 36. This is an example when the following is taken into consideration: For example, if there are two heating / vaporizing units 36, the objects 100 to be sterilized placed on the upper main shelf 23 are located above the upper heating / vaporizing unit 36, and therefore are mainly subjected to the heat of the upper heating / vaporizing unit 36, and are relatively less subjected to the heat of the lower heating / vaporizing unit 36. On the other hand, the objects 100 to be sterilized placed on the lower main shelf 23 are located between the upper and lower heating / vaporizing units 36, and therefore are more likely to be subjected to the heat of both the upper and lower heating / vaporizing units 36. In other words, the objects 100 to be sterilized placed on the lower main shelf 23 may be more easily heated than the objects 100 to be sterilized placed on the upper main shelf 23.

[0049] In another example, the lower heating / vaporizing unit 36 ​​is closer to the bottom wall 21b of the sterilization chamber 11 and may lose heat more easily than the upper heating / vaporizing unit 36. For this reason, the heating setting temperature of the lower heating / vaporizing unit 36 ​​may be set higher than that of the upper heating / vaporizing unit 36.

[0050] In another example, the heating set temperatures of both heating and vaporizing units 36 may be the same.

[0051] As another example, the heating temperature setting of the heating / vaporizing unit 36 ​​can be set according to the object 100 to be sterilized placed on the main shelf 23 corresponding to the heating / vaporizing unit 36. For example, the heating temperature setting of one heating / vaporizing unit 36 ​​may be set for the object 100 to be sterilized, which is a thoracotomy fixation tool that is a mass of metal (for example, titanium alloy), and the heating temperature setting of the other heating / vaporizing unit 36 ​​may be set to a temperature for the object 100 to be sterilized that is wrapped in a silicone pin mat and further packed in nonwoven fabric.

[0052] Next, the operation of the sterilizer 1 will be described. The following operation is controlled by the control device 3. During the following operation, the external heater 25 is operating, heating the sterilization chamber 11a from outside the sterilization chamber 11a. With the solenoid valve 34 closed, the sterilizer 1 uses the vacuum pump 37 to reduce the pressure in the sterilization chamber 11a and in the space in the fluid circuit between the sterilization chamber 11a and the solenoid valve 34. The sterilizer 1 opens the solenoid valve 34 when the pressure in the sterilization chamber 11a drops to a specified pressure. As a result, the sterilant discharged from the concentrator 33 flows toward the sterilization chamber 11a and is then distributed by the distributor 35 to each heating / vaporization unit 36. In each heating / vaporization unit 36, the sterilant flows from the supply port 42b to between the two plates 45, 46 and is heated by the heating section 43 between the two plates 45, 46. As a result, the sterilant expands thermally between the two plates 45, 46, is drawn into a vacuum, and spreads concentrically, instantly increasing the contact area between the two plates 45, 46. At this time, the heating unit 43 heats the sterilant, thereby promoting its vaporization. As a result, the sterilant instantly evaporates to the saturated vapor pressure between the two plates 45, 46. In other words, the sterilant vaporizes between the two plates 45, 46. This prevents a time lag from occurring between the vaporization of water molecules in the hydrogen peroxide solution and the vaporization of hydrogen peroxide molecules. Here, the ratio of hydrogen peroxide to water in the vaporized sterilant (gas) is 60% hydrogen peroxide and 40% water, or close to that ratio.

[0053] The gaseous sterilant flows out from outlet 42c into sterilization chamber 11a outside the two plates 45, 46. The gaseous sterilant that enters sterilization chamber 11a flows upward and comes into contact with objects 100 to be sterilized placed on main shelf 23. This sterilizes objects 100 to be sterilized. In this way, the sterilant is vaporized in vaporizer 42 directly below main shelf 23, and the vaporized sterilant reaches objects 100 to be sterilized on main shelf 23. Therefore, the sterilant vaporized in vaporizer 42 can reach objects 100 to be sterilized in a relatively short time and over a short distance. Therefore, the ratio of hydrogen peroxide to water in the gas that reaches objects 100 to be sterilized is likely to be maintained at or close to 60% hydrogen peroxide and 40% water.

[0054] At this time, the heating unit 43 heats (warms) the object 100 to be sterilized. That is, the heating unit 43 heats the object 100 to be sterilized when the sterilant supply unit 12 is supplying a sterilant to the sterilization chamber 11a. Specifically, the heating unit 43 heats (warms) the object 100 to be sterilized with radiant heat. As described above, each heating unit 43 is independently controlled by the control unit 3 so that the temperature of the heating unit 43 detected by the temperature sensor 44 is maintained at the heating set temperature. As an example, the heating unit 43 is controlled so that the temperature of the heating unit 43 is a first temperature during sterilization, and is controlled so that the temperature of the heating unit 43 is a second temperature lower than the first temperature during standby (non-sterilization). The first temperature is, for example, a temperature within a specified range including 80°C, and the second temperature is a temperature within a specified range including 55°C. The standby temperature is the same as the temperature at a location within the sterilization chamber 11a that is relatively far from the case 41.

[0055] As mentioned above, the ratio of hydrogen peroxide to water in an aqueous hydrogen peroxide solution is 60% hydrogen peroxide and 40% water, or a value close to that, for the following reason: An aqueous hydrogen peroxide solution is provided in a solution with a concentration of, for example, about 60% (actually 59%), which is composed of 60% hydrogen peroxide molecules and 40% water, and hydrogen peroxide has a high affinity for water, so it exists as an aqueous solution without reacting or bonding.

[0056] When such an aqueous hydrogen peroxide solution vaporizes, water tends to evaporate first, followed by hydrogen peroxide. This is simply due to the difference in molecular mass (H2O = 18, H2O2 = 34), and this tendency remains the same whether vacuum evaporation or thermal evaporation is used. Due to this tendency, in the initial stage of evaporation of the aqueous hydrogen peroxide solution, water evaporates and hydrogen peroxide evaporates later. For this reason, when sterilizing an object 100, the water that evaporates first tends to reach the object 100 first, forming a water film, which causes hydrogen peroxide to reach the object 100 later. In this case, the hydrogen peroxide that arrives at the object 100 is diluted by the water film that arrived at the object 100 earlier, which may make it difficult to achieve a significant sterilization effect. In contrast, in this embodiment, as described above, the sterilant is vaporized instantly between the two plates 45, 46, which suppresses the time difference between the vaporization of water and hydrogen peroxide in the hydrogen peroxide solution, and therefore tends to reduce the difference in the arrival times of the hydrogen peroxide and water at the object to be sterilized 100. This tends to increase the sterilizing effect of the hydrogen peroxide.

[0057] Next, we will explain the vaporization of aqueous hydrogen peroxide solutions. First, let us consider the case where a few milliliters of 60% aqueous hydrogen peroxide solution is dropped onto an evaporating dish heated to approximately 80°C under a vacuum of approximately 100 Pa. In this case, one might expect the hydrogen peroxide solution to evaporate instantly. However, like a drop of water dropped onto an object such as a frying pan, a few milliliters of hydrogen peroxide solution will gradually reduce in volume, splitting slightly and eventually evaporating completely, while some of the solution will bounce and some will dance. If this evaporation process is stopped midway and the concentration of the remaining hydrogen peroxide solution is measured, it is measured to be higher than approximately 60%. Furthermore, we observed that the hydrogen peroxide concentration is higher in the middle stage than in the early stage, and higher in the late stage than in the middle stage. This indicates that the water molecules in the heated hydrogen peroxide solution evaporate preferentially over time, and this is due to molecular weight. It is believed that the smaller the molecular weight, the more easily the water molecules vibrate and evaporate, leading to the evaporation of water molecules before the hydrogen peroxide molecules. This tendency in the order of evaporation is considered unavoidable because it is believed to be caused by molecular weight, but it is believed that the order of evaporation can be effectively ignored if the evaporation phenomenon itself is completed in an extremely short time. In this embodiment, based on the above concept, two plates 45, 46 are provided as described above, and the hydrogen peroxide solution is instantly evaporated between these plates 45, 46.

[0058] As explained above, in this embodiment, the sterilizer 1 comprises a sterilization cabinet 11, a sterilizing agent supply unit 12, multiple heating units 43, and a control device 3. The sterilization cabinet 11 has a sterilization chamber 11a therein that contains the objects to be sterilized 100. The sterilizing agent supply unit 12 vaporizes the liquid sterilizing agent by reducing the pressure inside the sterilization chamber 11a, and supplies the vaporized sterilizing agent to the sterilization chamber 11a. The multiple heating units 43 heat the objects to be sterilized 100 contained in the sterilization chamber 11a. The control device 3 controls each of the multiple heating units 43 independently.

[0059] With this configuration, it is possible to sterilize the object 100 with the vaporized sterilizing agent while the object 100 is heated by the heating unit 43. That is, the vaporized sterilizing agent can be made to act on the object 100 that has been sufficiently heated by the heating unit 43. This improves the sterilization performance of the sterilizer 1 compared to a configuration in which the object 100 is sterilized only with the vaporized sterilizing agent without heating the object 100. Furthermore, because the control unit 3 independently controls each of the multiple heating units 43, it is easy to maintain the temperature of the object 100 at the target temperature.

[0060] Furthermore, in this embodiment, the sterilizer 1 includes an outer heater 25 (outer heating unit). The outer heater 25 is disposed outside the sterilization chamber 11 and heats the sterilization chamber 11. That is, the outer heater 25 heats the sterilization chamber 11a. A plurality of heating units 43 are housed in the sterilization chamber 11a.

[0061] With this configuration, the outer heater 25 heats the sterilization chamber 11, which tends to prevent the inside of the sterilization chamber 11, i.e., the sterilization chamber 11a, from cooling down. In addition, since the multiple heating units 43 are housed in the sterilization chamber 11a, the heat of the heating units 43 is easily transferred to the objects 100 to be sterilized.

[0062] In this embodiment, the sterilization cabinet 11 has walls (upper wall 21a, lower wall 21b, right wall 21c, left wall 21d, rear wall 21e, and door 22) surrounding the sterilization chamber 11a. The specific heat of each of the multiple heating units 43 is lower than the specific heat of the walls (upper wall 21a, lower wall 21b, right wall 21c, left wall 21d, rear wall 21e, and door 22).

[0063] With this configuration, the specific heat of the heating section 43 is lower than that of the walls (upper wall 21a, lower wall 21b, right wall 21c, left wall 21d, rear wall 21e, door 22), so the heating section 43 can reach the target temperature in a shorter time than when the specific heat of the heating section 43 is higher than that of the above walls.

[0064] In this embodiment, the sterilizer 1 includes a plurality of main shelves 23 (shelves) arranged at intervals in the vertical direction of the sterilization chamber 11a of the sterilization cabinet 11, on which the objects to be sterilized 100 are placed. The sterilant supply section 12 includes a plurality of heating / vaporizing units 36 (units) arranged vertically below different main shelves 23. Each heating / vaporizing unit 36 ​​includes a heating section 43, a pair of plates 45, 46 facing each other at a distance, and a case 41 that houses the heating section 43 and supports the pair of plates 45, 46. The heating section 43 is provided around the pair of plates 45, 46. The sterilant supply section 12 includes a supply port 42b that supplies a liquid sterilant between the pair of plates 45, 46, and an outlet 42c that is spaced from the supply port 42b in a direction intersecting the vertical direction and through which the sterilant between the pair of plates 45, 46 flows out of the space between the pair of plates 45, 46. The disinfectant is vaporized between a pair of plates 45,46.

[0065] According to this configuration, the heating section 43 is disposed below the main shelf 23, and therefore the heating section 43 can be easily disposed near the main shelf 23. Therefore, the amount of heat applied to the objects 100 to be sterilized by the heating section 43 can be easily increased.

[0066] Furthermore, with the above configuration, the gaseous sterilant is sprayed between the two plates 45, 46 (for example, a gap with a fixed distance), allowing the gaseous sterilant to be dispersed uniformly. Furthermore, the liquid sterilant supplied between the two plates 45, 46 from the supply port 42b spreads between the two plates 45, 46, allowing the heat of the heating unit 43 to be easily transferred to the sterilant. Therefore, the sterilant can be vaporized in a relatively short time. Furthermore, since the two plates 45, 46 are disposed below the main shelf 23, the gaseous sterilant coming out of the outlet 42c rises and reaches the object 100 to be sterilized on the main shelf 23. Therefore, the gaseous sterilant can be easily supplied to the object 100 to be sterilized relatively quickly.

[0067] Here, for example, in a configuration in which the vaporizer is located outside the sterilization chamber, the distance from the vaporizer to the object to be sterilized is long, and the sterilant may condense in relatively low-temperature areas, such as the inside of the pipe leading from the vaporizer to the sterilization chamber, resulting in a decrease in concentration due to the loss of hydrogen peroxide molecules. In contrast, in this embodiment, vaporizer 42 (two plates 45, 46) is housed inside sterilization chamber 11a, allowing the vaporized sterilant to reach object 100 in a relatively short time and over a short distance. Therefore, the temperature of the sterilant is less likely to decrease before reaching object 100. This makes it easier to suppress crystallization of the vaporized sterilant.

[0068] Furthermore, according to the above configuration, the heating section 43 and the two plates 45, 46 are included in the heating / vaporization unit 36, so it is easier to install the heating section 43 and the two plates 45, 46 in the sterilization chamber 11a than in a configuration in which the heating section 43 and the two plates 45, 46 are separate.

[0069] In this embodiment, the control device 3 controls the heating section 43 so that the temperature of the heating section 43 becomes a target temperature. The target temperature of the heating section 43 differs for each heating / vaporization unit .

[0070] Here, the multiple heating and vaporizing units 36 are located at different positions, and therefore the effects of radiant heat and the amount of heat emitted by the heating and vaporizing units 36 absorbed by the sterilization chamber 11 are different from one another. In contrast, in this embodiment, as described above, the target temperature of the heating section 43 is different for each heating and vaporizing unit 36, and therefore it is easy to maintain the temperature of the objects to be sterilized 100 at the target temperature for each heating and vaporizing unit 36.

[0071] Here, the heating / vaporization unit 36 ​​reaches a high temperature of, for example, 80°C during sterilization, and after sterilization, it takes time for the temperature to drop to a temperature (for example, 60°C) that an operator can touch. In contrast, in this embodiment, the main shelf 23 is provided with a net 26 having a lower specific heat than the main shelf 23. Because the net 26 has a lower specific heat than the main shelf 23, it cools down more quickly than the main shelf 23. Therefore, when an operator pulls out the main shelf 23 to remove the objects 100 to be sterilized after the sterilization operation by the sterilizer 1 is completed, the operator can simply pull out the main shelf 23 via the net 26, whose temperature has dropped compared to the main shelf 23. This allows the operator to pull out the main shelf 23 without directly touching the high-temperature heating / vaporization unit 36 ​​or the case 41. The net 26 is a safety fence to prevent the operator's fingers from coming into contact with the heating / vaporization unit 36.

[0072] Next, a modified example will be described. Fig. 8 is a plan view showing an example of a part of heating / evaporation unit 36 ​​of a modified embodiment, showing the part other than upper wall 41a. In this modified example, heating section 43 has two uneven sections 43e, 43f and two linear sections 43g, 43h.

[0073] The two uneven portions 43e, 43f extend in the front-rear direction and are spaced apart in the width direction. The uneven portion 43f is located to the right of the uneven portion 43e. The two carburetors 42 are located between the two uneven portions 43e, 43f.

[0074] The two linear portions 43g, 43h each extend in the width direction and are parallel to each other with a gap in the front-rear direction. The linear portion 43h is located rearward of the linear portion 43g. The two carburetors 42 are located between the two linear portions 43g, 43h. The linear portion 43g spans the front ends of the two concave-convex portions 43e, 43f. The linear portion 43h extends leftward from the rear end of the concave-convex portion 43f.

[0075] In this modification, the uneven portion 43e is thermally connected to the temperature sensor 44 via the heat transfer member 52.

[0076] Next, we will explain a plasma sterilization device as a reference example. The plasma sterilization device uses a method in which plasma is discharged using electrodes that are punched metal plates in a space of, for example, 1 inch, and the material is heated by the heat of the discharge.

[0077] Low-temperature sterilization using hydrogen peroxide gas began in the United States in the 1990s, and sales of such equipment began in Japan around 1997. This sterilization method was called plasma sterilization because the sterilization process involved creating a vacuum of approximately 30 Pa to generate plasma. At the time, the vacuum-vaporized hydrogen peroxide molecules collided with electrons emitted by the plasma discharge, separating them and generating OH radicals. These OH radicals had a bactericidal effect, and manufacturers described and marketed them as such. However, the OH radicals generated by electron collisions were extremely short-lived and disappeared before reaching the target. Furthermore, plasma discharge primarily occurred in the space between the antenna and the sterilization chamber, unrelated to the target, and only a small number of electrons reached the space where the target was located. Furthermore, the generation of hydrogen peroxide gas caused the pressure inside the sterilization chamber to rise to 1600 Pa, making it impossible to generate plasma or other similar substances. Furthermore, at around 30 Pa, where plasma is generated, there are almost no hydrogen peroxide molecules present in a concentration sufficient to cause a sterilizing effect, and even if sterilization does occur, it is thought that the effect would be extremely slight.

[0078] Currently, experts believe that the primary role of plasma is to decompose residual hydrogen peroxide after the sterilization process is complete. However, the reason why plasma sterilization devices still exist and are sold is because plasma has effects other than those described above. In other words, it is not the emitted electrons that are effective in sterilizing, but the discharge heat emitted from the antenna due to the plasma discharge. To efficiently sterilize gases other than hydrogen peroxide, it is necessary to heat the object to a certain low temperature. In the case of plasma sterilization, it is thought that this discharge heat warms the object, thereby increasing the sterilization effect.

[0079] Therefore, current plasma sterilizers include a plasma process at the beginning of the sterilization process, prior to the hydrogen peroxide release process. For example, the pressure is reduced at the beginning of the sterilization process, followed by a 10-15 minute plasma discharge period. As previously explained, plasma does not occur until the pressure is reduced to approximately 30 Pa. During this period, even if hydrogen peroxide is introduced, it is immediately sucked out by the vacuum pump. If the vacuum pump is stopped, the pressure rises and plasma does not occur. In other words, only air plasma is used during this period. The discharge color of air plasma appears pink, but this is due to the nitrogen being colored, and air plasma can be considered nitrogen plasma. Since nitrogen is a very stable molecule, if air plasma does not contribute to sterilization, the only thing that contributes to sterilization is heating (warming). If heating is considered to contribute to sterilization, then after 10 to 15 minutes of heating, the heat from this process heats the object to be sterilized, and this heat contributes to the sterilization action of the hydrogen peroxide gas introduced later, regardless of the plasma.

[0080] However, the above plasma devices are too expensive and complicated to be used as heating devices.

[0081] In the above embodiment, the heating / vaporization unit 36 ​​is disposed below the main shelf 23, but this is not limiting. For example, the heating / vaporization unit 36 ​​may be placed on the right wall 21c, the left wall 21d, or the upper wall 21a above the heating / vaporization unit 36. In addition, in the above embodiment, the sub-shelf 24 is provided, but the sub-shelf 24 does not have to be provided.

[0082] Although several embodiments of the invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the scope of the invention and its equivalents as defined in the claims.

[0083] According to at least one of the embodiments described above, it is possible to improve the sterilization performance. [Explanation of symbols]

[0084] 1...sterilization device, 3...control device, 11...sterilization cabinet, 11a...sterilization chamber, 12...sterilant supply section, 21a...upper wall (wall), 21b...lower wall (wall), 21c...right wall (wall), 21d...left wall (wall), 21e...rear wall (wall), 22...door (wall), 23...main shelf (shelf), 25...external heater (external heating section), 36...heating / vaporization unit (unit), 41...case, 42b...supply inlet, 42c...outlet, 43...heating section, 45, 46...plate, 100...object to be sterilized.

Claims

1. a sterilization cabinet having a sterilization chamber therein for accommodating objects to be sterilized; a sterilizing agent supply unit that vaporizes the liquid sterilizing agent by reducing the pressure inside the sterilization chamber and supplies the vaporized sterilizing agent to the sterilization chamber; A plurality of heating units for heating the objects to be sterilized contained in the sterilization chamber; a control device that independently controls each of the plurality of heating units; A plurality of shelves arranged at intervals in the vertical direction of the sterilization cabinet in the sterilization chamber, on which the objects to be sterilized are placed; Equipped with The sterilization cabinet has a wall surrounding the sterilization chamber, a specific heat capacity of each of the plurality of heating portions is lower than a specific heat capacity of the wall; the sterilant supply unit has a plurality of units arranged below different shelves in the up-down direction, Each of the units includes the heating unit, a pair of plates facing each other in the vertical direction with a gap therebetween, and a case that houses the heating unit and supports the pair of plates, The heating unit is provided around the pair of plates, The sterilant supply unit is provided with a supply port that supplies the liquid sterilant between the pair of plates, and an outlet that is spaced from the supply port in a direction intersecting the vertical direction and through which the sterilant between the pair of plates flows out of the space between the pair of plates, The disinfectant is vaporized between the pair of plates. Sterilizer.

2. An external heating unit is provided outside the sterilization chamber and heats the sterilization chamber, The sterilizer according to claim 1 , wherein the plurality of heating units are housed in the sterilization chamber.

3. the control device controls the heating unit so that the temperature of the heating unit reaches a target temperature; The sterilizer according to claim 1 , wherein the target temperatures of the heating sections are different for each of the units.

4. a sterilization cabinet having a sterilization chamber therein for accommodating objects to be sterilized; a sterilizing agent supply unit that vaporizes the liquid sterilizing agent by reducing the pressure inside the sterilization chamber and supplies the vaporized sterilizing agent to the sterilization chamber; A plurality of heating units for heating the objects to be sterilized contained in the sterilization chamber; a control device that independently controls each of the plurality of heating units; A plurality of shelves arranged at intervals in the vertical direction of the sterilization cabinet in the sterilization chamber, on which the objects to be sterilized are placed; Equipped with The plurality of heating units include a heating / vaporization unit that heats the liquid sterilant arranged below the shelf on which the objects to be sterilized contained in the sterilization chamber are placed, thereby promoting vaporization of the sterilant. Sterilizer.

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