Sterilization device

Abstract

To prevent blowout of a liquid sterilant into a sterilization chamber.SOLUTION: A sterilization device includes a sterilization chamber, a shelf, a decompression part, a heating part, two plates, and a supply part. The shelf is stored in the sterilization chamber, and allows an object to be sterilized to be mounted thereon. The decompression part decompresses the inside of the sterilization chamber, and thereby vaporizes a sterilant. The heating part is stored in the sterilization chamber, and heats the sterilant supplied to the sterilization chamber. The two plates are arranged on the lower side of the shelf in the sterilization chamber, and face each other in a vertical direction of the sterilization chamber at an interval. The supply part is provided between the two plates, and supplies the liquid sterilant between the two plates. In the two plates, a groove located in the vicinity of both ends in a width direction of the sterilization chamber crossing the vertical direction is formed, on a surface facing the other plate of at least one plate of the two plates.SELECTED DRAWING: Figure 5

Description

[Technical Field]

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

[0002] Conventionally, sterilization devices have been known that reduce the pressure in a sterilization chamber within a sterilizer, vaporize a sterilant such as an aqueous hydrogen peroxide solution while drawing the sterilant into the sterilization chamber, and sterilize objects contained in the sterilization chamber with the vaporized sterilant. For example, a method used in this type of sterilization device is to sterilize objects by evaporating an aqueous hydrogen peroxide solution under vacuum and using the hydrogen peroxide vapor.

[0003] In conventional sterilization equipment, a method of vaporizing a sterilant may be used, for example, by heating multiple metal vaporization plates (hereinafter also referred to as parallel plates) spaced 1 mm or less apart, and then pouring a liquid sterilant at room temperature and pressure into the center of the parallel plates to vaporize it. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2023-20548 Summary of the Invention [Problem to be solved by the invention]

[0005] It is known that when vaporizing a sterilant using parallel plates, the temperature of the parallel plates drops due to evaporative cooling at the end of vaporization (when the sterilant evaporates), and this also tends to decrease the degree of vacuum inside the sterilizer.

[0006] For this reason, for example, when vaporizing a sterilant or the like continuously in a short period of time, the liquid sterilant may not be vaporized sufficiently, and the sterilant may diffuse in its liquid form. The force of the vaporized sterilant's diffusion may cause the liquid sterilant to spray into the sterilization chamber.

[0007] The items to be sterilized may have labels or other items attached to them. In such cases, if a highly concentrated aqueous hydrogen peroxide solution used as a sterilant is sprayed in liquid form onto the items to be sterilized, the labels may peel off or the writing on the labels may disappear.

[0008] One of the problems that the embodiments disclosed herein aim to solve is to prevent the liquid sterilant from spraying into the sterilization chamber. However, the problems solved by the embodiments disclosed herein are not limited to the above problem. Problems corresponding to the effects of the configurations described in the embodiments below can also be considered as other problems that the embodiments disclosed herein aim to solve. [Means for solving the problem]

[0009] The sterilization apparatus according to the embodiment comprises a sterilization chamber, a shelf, a pressure reduction unit, a heating unit, two plates, and a supply unit. The shelf is housed in the sterilization chamber and holds the objects to be sterilized. The pressure reduction unit vaporizes the sterilant by reducing the pressure inside the sterilization chamber. The heating unit is housed in the sterilization chamber and heats the sterilant supplied to the sterilization chamber. The two plates are located below the shelf in the sterilization chamber and face each other in the vertical direction of the sterilization chamber with a gap between them. The supply unit is located between the two plates and supplies liquid sterilant between the two plates. The two plates have grooves formed on the surface of at least one of the plates facing the other plate, near both ends in the width direction of the sterilization chamber that intersects with the vertical direction. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a diagram showing an example of the configuration of a sterilization apparatus 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 according to the embodiment. [Figure 3] FIG. 3 is a plan view showing an example of a main shelf of the sterilization apparatus according to the embodiment. [Figure 4]FIG. 4 is a plan view showing an example of a part of the heating and vaporizing unit of the sterilization apparatus according to the embodiment. [Figure 5] FIG. 5 is a cross-sectional view showing an example of a part of a cross section taken along line VV in FIG. [Figure 6] FIG. 6 is a diagram illustrating the flow of vaporized sterilant in the sterilization apparatus according to the embodiment. [Figure 7] FIG. 7 is a cross-sectional view showing an example of a part of a cross section taken along line VII-VII in FIG. [Figure 8] FIG. 8 is a cross-sectional view showing an example of a part of a cross section taken along line VIII-VIII in FIG. [Figure 9] FIG. 9 is a diagram illustrating the flow of vaporized sterilant in a sterilization apparatus according to a comparative example. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings, but the present invention is not limited to these embodiments.

[0012] The following embodiments include similar components. These similar components are assigned common reference numerals, and redundant descriptions are omitted. The drawings are schematic, and the dimensional relationships and ratios of elements may differ from reality. The drawings may also include portions with different dimensional relationships and ratios. In this specification, ordinal numbers are used only to distinguish between parts, members, portions, positions, directions, etc., and do not indicate order or priority.

[0013] 1 is a diagram showing an example of the configuration of a sterilization apparatus 1 according to an embodiment. As shown in FIG. 1, the sterilization apparatus 1 comprises a sterilization processing section 2 and a control device 3.

[0014] Sterilization treatment unit 2 vaporizes a liquid sterilant and sterilizes object 100 with the vaporized sterilant. The liquid sterilant is, for example, an aqueous hydrogen peroxide solution. Object 100 is, for example, a medical device such as an endoscope, an endoscopic video camera, or a medical plastic product, but may also be other objects. Control unit 3 controls sterilization treatment unit 2.

[0015] In this specification, sterilization includes sterilization, disinfection, sterilization, or disinfection of an object. In addition, in this specification, sterilization can be interpreted as sterilization, disinfection, or disinfection.

[0016] Sterilization refers to the destruction of all bacteria, viruses, and other microorganisms present on an object, regardless of whether they are harmful or harmless. Sterilization refers to the destruction (inactivation) of bacteria, viruses, and other microorganisms present on an object. Disinfection refers to the reduction of the number of bacteria, viruses, and other microorganisms present on an object. Disinfection refers to the destruction (or removal) of pathogenic bacteria, viruses, and other microorganisms present on an object, rendering them harmless.

[0017] The sterilization processing unit 2 comprises a sterilization cabinet 11 and a sterilizing agent supply unit 12. A sterilization chamber 11a is provided inside the sterilization cabinet 11 to house objects to be sterilized 100, and the sterilizing agent supply unit 12 supplies a sterilizing agent to the sterilization chamber 11a. The sterilization chamber 11a is also referred to as a chamber.

[0018] For convenience, three mutually orthogonal directions are defined in this embodiment: the X direction corresponds to the rear of the sterilization chamber 11 in the front-to-rear direction (depth direction), the Y direction corresponds to the width direction of the sterilization chamber 11, and the Z direction corresponds to the upper side of the sterilization chamber 11 in the up-down direction (height direction).

[0019] The sterilant supply section 12 includes a cartridge 31, a liquid phase pump 32, a concentrator 33, a solenoid valve 34, a distributor 35, a heating and vaporizing unit 36, a vacuum pump 37, a solenoid valve 38, and a vacuum gauge 39. The cartridge 31, the liquid phase pump 32, the concentrator 33, the solenoid valve 34, the distributor 35, and the heating and vaporizing unit 36 ​​form a fluid circuit.

[0020] The vacuum pump 37 sucks gas from the sterilization cabinet 11, i.e., the sterilization chamber 11a, the heating / vaporization unit 36, and the distributor 35, reducing the pressure in each space to create a vacuum (a space filled with gas at negative pressure, which is lower than atmospheric pressure). A vacuum state is also called a negative pressure state. The vacuum pump 37 is an example of a pressure reducing section.

[0021] Cartridge 31 contains a liquid sterilant (concentrate). Liquid phase pump 32 sucks the liquid sterilant from cartridge 31 and discharges the sucked liquid sterilant to concentrator 33. In other words, liquid phase pump 32 supplies the sterilant to concentrator 33. Liquid phase pump 32 is a tube pump that can measure the amount of sterilant sucked in and discharged.

[0022] 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.

[0023] The solenoid valve 34 is provided between the concentrator 33 and the sterilization chamber 11a. When the solenoid valve 34 opens, the sterilant from the concentrator 33 is supplied to the sterilization chamber 11a if the sterilization chamber 11a is under negative pressure.

[0024] 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.

[0025] The four vaporizers 42 vaporize the liquid sterilant and supply the gaseous sterilant into the sterilization chamber 11a.

[0026] 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 isolates 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. A vacuum gauge 39 measures the degree of vacuum in the sterilization chamber 11a.

[0027] Figure 2 is a front view showing an example of a part of the sterilization cabinet 11 in the sterilization apparatus 1 according to the embodiment. Figure 2 shows 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 stored in the sterilization chamber 11a.

[0028] The sterilization chamber 11 is in the shape of a substantially rectangular parallelepiped box 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.

[0029] 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.

[0030] 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.

[0031] Door 22 is rotatably supported at the front end of upper wall 21a, lower wall 21b, right wall 21c, or left wall 21d, and can be opened and closed relative to main body 21. Door 22 is the front wall of sterilization cabinet 11. When closed, door 22 extends in a direction perpendicular to the front-to-rear direction, overlapping with the front ends of upper wall 21a, lower wall 21b, right wall 21c, and left wall 21d, thereby closing off sterilization chamber 11a. When door 22 is opened, sterilization chamber 11a is exposed to the front.

[0032] 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.

[0033] 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.

[0034] As shown in Figure 1, external heaters 25 are superimposed on the outer surfaces of the door 22, top wall 21a, bottom wall 21b, right wall 21c, left wall 21d, and rear wall 21e. The external heaters 25 heat the interior of the sterilization cabinet 11, i.e., the sterilization chamber 11a, from outside the sterilization cabinet 11. Note that Figure 1 only shows a portion of the external heaters 25. The external heaters 25 have a heat source such as a sheet heater. Hereinafter, the temperature during sterilization in the sterilization chamber 11a may be referred to as the sterilization temperature.

[0035] As shown in Figure 2, the sterilization chamber 11a contains two main shelves 23, two sub-shelves 24, and two heating and vaporizing units 36. The main shelves 23 are also referred to as the first shelves, and the sub-shelves 24 are also referred to as the second shelves.

[0036] The two main shelves 23 and the two sub-shelves 24 are arranged vertically with a gap between them. The lower main shelf 23 of the two main shelves 23 is arranged above the lower wall 21b, the lower sub-shelf 24 of the two sub-shelves 24 is arranged above the lower main shelf 23, the upper main shelf 23 of the two main shelves 23 is arranged above the lower sub-shelf 24, and the upper sub-shelf 24 of the two sub-shelves 24 is arranged above the upper main shelf 23.

[0037] Each main shelf 23 and sub-shelves 24 is detachably supported by supports 21f, 21g provided on the right wall 21c and 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. Items 100 to be sterilized can be placed on each of the two main shelves 23 and two sub-shelves 24.

[0038] Figure 3 is a plan view showing an example of the main shelf 23 of the sterilization apparatus 1 according to the embodiment. As shown in Figure 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 arranged at intervals from each other in the width direction. The multiple second members 23b extend in the width direction and are arranged at intervals from each other in the front-rear direction.

[0039] The plurality of first members 23a and the plurality of 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 the specific heat of the main shelf 23. The net 26 has a plurality of openings. Note that the net 26 does not necessarily have to be provided.

[0040] 2, the two heating / vaporizing units 36 are respectively disposed below the two main shelves 23. More specifically, the two heating / vaporizing units 36 are respectively disposed directly below the two main shelves 23. "Directly below" means that the vertical distance between the top end of the shelf heater 43 included in the heating / vaporizing unit 36 ​​and the top end of the main shelf 23 is equal to or less than half the vertical height of the space on the main shelf 23 that can accommodate the items to be sterilized 100 (hereinafter also referred to as the above-shelf storage space).

[0041] 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 that is adjacent to and above the main shelf 23 in the vertical direction. Note that the vertical distance between the upper end of the shelf heater 43 and the upper end of the main shelf 23 may be ¼ or less or 1 / 10 or less of the vertical height of the on-shelf storage space on the main shelf 23.

[0042] 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.

[0043] Figure 4 is a plan view showing an example of a part of the heating and vaporization unit 36 ​​of the sterilization apparatus 1 according to the embodiment. Figure 5 is a cross-sectional view showing an example of a part of a cross section taken along line VV in Figure 5. Figure 7 is a cross-sectional view showing an example of a part of a cross section taken along line VII-VII in Figure 4.

[0044] 1, 4, and 5, the heating and vaporization unit 36 ​​has a case 41, two vaporizers 42, a shelf heater 43, and a first temperature sensor 44. The shelf heater 43 is an example of a heating section.

[0045] 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. The case 41 is thinner than the sterilization cabinet 11.

[0046] The upper wall 41a and the lower wall 41b extend in a direction perpendicular to the vertical direction and are provided parallel to each other with a gap therebetween in the vertical direction. The upper wall 41a is provided with an opening 41aa (FIGS. 5 and 7).

[0047] The opening 41aa is a through-hole that penetrates the upper wall 41a in the vertical 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. As shown in Fig. 4, the left wall 41d is provided with an opening 41da. 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.

[0048] 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.

[0049] As shown in FIG. 1, the two plates 45, 46 are disposed below the main shelf 23 in the sterilization chamber 11a. As shown in FIGS. 4 and 5, the plates 45, 46 are flat. The two plates 45, 46 each extend in a direction perpendicular to the vertical direction and are arranged parallel to each other with a gap between them in the vertical direction. The two plates 45, 46 are also referred to as parallel flat plates. The thickness of the two plates 45, 46 is, for example, about 3 mm, but is not limited to this.

[0050] Plate 46 is disposed below plate 45. Plate 45 is fixed to the upper surface of upper wall 41a by fasteners 51 such as screws while covering a portion of opening 41aa of upper wall 41a. In other words, plate 45 is supported by upper wall 41a. It can be said that both ends in the width direction of the space between plates 45 and 46 in the vertical direction are sealed by upper wall 41a, and therefore upper wall 41a is an example of a sealing member. Furthermore, fasteners 51 are an example of a fixing device.

[0051] The plate 46 is disposed between the upper wall 41a and the lower wall 41b, and is fixed to the inner surfaces of the upper wall 41a and the lower wall 41b by fasteners 51. In other words, the plate 46 is supported by the upper wall 41a and the lower wall 41b.

[0052] The plate 46 has a facing portion 46a (Figs. 5 and 7) 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 in the front-to-rear direction relative to the plate 45. A plate 50 is provided between the plate 46 and the lower wall 41b. The plate 50 is made of, for example, aluminum.

[0053] Furthermore, plate 45 has a plurality of holes 45a (FIGS. 4 and 5) and grooves 45b (FIG. 5). Plate 46 has groove 46d. Holes 45a are holes with a diameter of about 10 mm. In this embodiment, holes 45a are holes with a diameter of about 10 mm, but the diameter of holes 45a is not limited to this.

[0054] The holes 45a are provided in the vicinity of the upper wall 41a in the vertical direction. The holes 45a are also arranged at approximately equal intervals in the width direction. Although nine holes 45a are provided in Fig. 4, the number of holes 45a is not limited to this.

[0055] The grooves 46d are provided along both widthwise ends of the facing portion 46a, and the grooves 45b are provided along positions facing the grooves 46d of the plate 45 in the up-down direction.

[0056] Here, the multiple holes 45a are provided for the purpose of improving sterilization efficiency. The reasons why the multiple holes 45a can achieve these purposes will be explained below. For comparison, first, the diffusion of sterilant when multiple holes 45a are not provided will be explained using Figure 9. Figure 9 is a diagram explaining the flow of vaporized sterilant in the sterilization apparatus 1a according to the comparative example.

[0057] The sterilization apparatus 1a in Figure 9 has a case 141. The case 141 has an upper wall (not shown), a lower wall (not shown), a right wall 141c, a left wall 141d, a rear wall 141e, and a front wall 141f. The configuration of the case 141 is similar to that of the case 41, so a description thereof will be omitted.

[0058] The vaporizer of sterilization apparatus 1a also has two plates 145, 146. Plates 145, 146 have the same configuration as plates 45, 46 except that plates 145, 146 do not have multiple holes 45a, grooves 45b, and grooves 46d. In other words, sterilization apparatus 1a has the same configuration as sterilization apparatus 1 except that plates 145, 146 do not have multiple holes 45a, grooves 45b, and grooves 46d.

[0059] In sterilization apparatus 1a, the vaporized sterilant is sprayed in the direction of the arrow in Figure 9 and then diffuses due to vacuum pressure and the expansion of the sterilant. The diffusion spreads into space from the slit through which the sterilant is sprayed (not shown in Figure 9, but similar to outlet 42c, described below), while the larger flow heads toward the center of the sterilization chamber (not shown in Figure 9, but similar to sterilization chamber 11a).

[0060] The vaporized sterilant travels through eight slits, two on the left and two on the right, in plates 145 installed in four locations within the sterilization chamber (only two are shown in Figure 9), toward the center of the sterilization chamber, sterilizing the objects 100 to be sterilized that lie between them.

[0061] The object 100 to be sterilized is placed on a mesh-like main shelf and net (not shown in Figure 9, but similar to main shelf 23 and net 26) placed directly above a unit (hereinafter referred to as the core unit) equipped with two plates 145, 146. At this time, the object 100 to be sterilized is generally placed in a bag (made of an antiviral material) with micropores that viruses cannot pass through, called a sterilization bag.

[0062] Furthermore, in the case of items 100 to be sterilized, such as expensive, complex, and highly functional medical instruments, they may be stored in dedicated cases or specific sterilization containers. These cases and containers are generally packaged in breathable nonwoven fabric made of antiviral material, similar to sterilization bags. Because sterilization devices are often used for the purpose of sterilizing endoscopes, the following explanation will be given using an example in which the items to be sterilized are packaged in nonwoven fabric (packaging material), as in the case of sterilizing an endoscope.

[0063] As described above, the vaporized sterilant is initially sprayed from the eight slits in the direction of the arrows in Figure 9, and then diffuses onto the object 100 to be sterilized. At this time, the medical device to be sterilized is packaged in a packaging material. The packaging material provides pressure resistance to the vaporized sterilant as it penetrates into the packaging material. In other words, the vaporized sterilant can only penetrate into the packaging material when a pressure difference of a certain level or more is created between the inside and outside of the packaging material.

[0064] Vaporized sterilant released into a vacuum diffuses toward areas with lower pressure. Therefore, the vaporized sterilant will not penetrate into the pressure-resistant packaging until a certain amount of vaporized sterilant has diffused. Vaporized sterilant generally sterilizes by oxidation, but oxidation is the exchange of electrons, so the faster the reaction, the better the sterilization process.

[0065] In this embodiment, in addition to providing a means for uniformly releasing vaporized sterilant within the sterilization chamber 11a, multiple holes 45a are provided in the plate 45 to release the vaporized sterilant directly onto the object 100 to improve sterilization efficiency.

[0066] 1 to 3, objects to be sterilized 100 are stored on a mesh-like main shelf 23, and two core units are placed directly below the main shelf 23. As mentioned above, conventionally, vaporized sterilant is sprayed in a generally horizontal direction from the core unit and then diffuses into the space. This structure is maintained in this embodiment.

[0067] In this embodiment, as shown in Figure 5, the plate 45 has multiple holes 45a in the upper part. The multiple holes 45a change the vector direction of the release of some of the vaporized sterilant. The release of the sterilant according to this embodiment will be explained below with reference to Figure 6. Figure 6 is a diagram explaining the flow of vaporized sterilant in the sterilization apparatus 1 according to this embodiment.

[0068] First, the flow of vaporized sterilant without multiple holes 45a will be described. Plates 145 and 146 in Figure 9 have slits at both ends in the width direction, and vaporized sterilant is released from these slits. Both front and rear ends of plates 145 and 146 are sealed by connectors (not shown in Figure 9, but similar to connector 51). Therefore, vaporized sterilant is not released from both front and rear ends of plates 145 and 146.

[0069] In contrast, in this embodiment, when liquid sterilant is supplied to the center of plates 45, 46, the liquid sterilant vaporizes while spreading concentrically. As with sterilization device 1a in Figure 9, the vaporized sterilant is released from outlet 42c (slit), but in this embodiment, multiple holes 45a are formed in plate 45, so some of the vaporized sterilant is released not only from outlets 42c at both ends in the width direction, but also from multiple holes 45a in the front-to-rear direction.

[0070] The vaporized sterilant released from the multiple holes 45a is released in an up-down (vertical) direction, with a phase shift of 90° from the direction of outlet 42c, as shown in Figure 6. Here, two plates 45, 46 are installed in the core unit, and objects to be sterilized 100 placed on main shelf 23 are placed vertically above the core unit.

[0071] Therefore, the vaporized sterilant released from the multiple holes is released directly onto the object 100. At this time, as mentioned above, the vaporized sterilant cannot penetrate into the packaging material unless a certain pressure difference is created.

[0072] In this embodiment, the vaporized sterilant can be sent into the packaging material by the amount of pressure change without waiting for the sterilization chamber 11a to fill with vaporized sterilant. In other words, the vaporized sterilant can enter the packaging material even while the vaporized sterilant is becoming uniform, before the internal pressure of the sterilization chamber 11a uniformly increases.

[0073] In other words, in this embodiment, the vaporized sterilant does not penetrate into the packaging material once it has become uniform, but the vaporized sterilant can penetrate into the interior of the packaging material even while it is becoming uniform, thereby improving sterilization efficiency.

[0074] However, depending on various sterilization conditions, such as the vacuum pressure when vaporizing the liquid sterilant and the type and temperature of the object 100 to be sterilized, the evaporation rate of the sterilant may decrease. In this case, the sterilant may diffuse in a liquid state, causing the liquid sterilant to spray out of the multiple holes 45a. Furthermore, if the liquid sterilant sprays out of the multiple holes 45a, it will be released directly toward the object 100 to be sterilized.

[0075] If the object 100 is stored in a case, container, etc., the liquid sterilant will not come into direct contact with the object 100, but a management label may be affixed to the case, container, etc. In this case, the liquid sterilant may erase the characters printed on the label or make the label more likely to peel off. For this reason, it is considered best to avoid the liquid sterilant coming into direct contact with the object 100 as much as possible.

[0076] In this embodiment, as shown in Figure 5, plate 46 is provided with groove 46d. Therefore, even if the sterilant diffuses in liquid form, groove 46d enlarges the space that serves as the path for the sterilant to diffuse, significantly reducing the force of gap diffusion, which is the driving force behind the diffusion of the liquid sterilant. The weakened diffusion force causes the liquid sterilant to overflow and pool in groove 46d, completely stopping diffusion.

[0077] Furthermore, in this embodiment, plate 45 has groove 45b similar to groove 46d, which increases the volume inside hole 45a. By increasing the volume inside hole 45a, the force with which the liquid sterilant rises outward from hole 45a can be reduced. This prevents the sterilant from spraying out of hole 45a even if it diffuses in a liquid state.

[0078] Furthermore, the sterilant whose diffusion is stopped by grooves 45b and 46d will eventually evaporate, so that the liquid sterilant remaining in grooves 45b and 46d will not adversely affect the user.

[0079] Even in the case of a sterilization apparatus 1a configured without holes 45a, if the evaporation rate decreases, the force of diffusion of the vaporized sterilant may cause the liquid sterilant to spray into the sterilization chamber from a widthwise slit, etc. In this case, by providing at least one of grooves 45b and 46d, the diffusing force of the liquid sterilant can be reduced, preventing the liquid sterilant from spraying into the sterilization chamber.

[0080] 5 and 7, vaporizer 42 is provided with supply port 42b and outlet 42c (FIG. 7). 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, 46, inside an outer edge portion 46c of plate 46.

[0081] 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, 46. Gap 42a is a passage for the sterilant. Gap 42a is included in opening 41aa in upper wall 41a.

[0082] Tube 48 transports the sterilant. Tube 48 is also referred to as piping. Tube 48 may be made of different materials inside and outside heating / vaporizing unit 36. In this case, tube 48 inside heating / vaporizing unit 36 ​​is made of a metal material that is heat-resistant and corrosion-resistant.

[0083] The material of the tube 48 in the heating / evaporation unit 36 ​​is not particularly limited, but it is preferably made of a metal material containing aluminum. Using aluminum as the material can prevent the generation of hexavalent chromium (a carcinogenic substance), which may be generated by heating stainless steel at high temperatures. The tube 48 may also be made of stainless steel, but in this case, the temperature must be controlled to prevent it from being heated too high.

[0084] In this embodiment, the tube 48 is configured by connecting an aluminum tube 48a and a heat-resistant silicone tube 48b. The aluminum tube 48a may be made of aluminum alone or may be made of various aluminum alloys. The aluminum tube 48a is installed in the heating / evaporation unit 36 ​​so as to run parallel to the shelf heater 43.

[0085] 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.

[0086] The shelf heater 43 heats at least a portion of the aluminum tube 48a in the sterilization chamber 11a, and also heats the object 100 to be sterilized in the sterilization chamber 11a.

[0087] As shown in FIG. 1, the shelf heater 43 is disposed below the main shelf 23 in the sterilization chamber 11a. Also, as shown in FIG. 4, the shelf heater 43 is provided around the two plates 45, 46 of each of the two sets 47. The shelf heater 43 is a single sheathed heater that has been bent. The sheathed heater may include, for example, a stainless steel pipe that forms 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 to this. The shelf heater 43 has a relatively low specific heat.

[0088] The shelf heater 43 has a plurality of first extensions 43a, a plurality of second extensions 43b, a plurality of third extensions 43c, a plurality of connecting portions 43d, and two fourth extensions 43e. The first extensions 43a all extend in the width direction and are arranged parallel to each other with a gap in the front-rear direction. The evaporator 42 is disposed between the two first extensions 43a.

[0089] In addition, the multiple first extension portions 43a, except for the first extension portion 43a located at the frontmost side, the first extension portion 43a located second from the front, the first extension portion 43a located at the rearmost side, and the first extension portion 43a located second from the rear, are welded to the aluminum tube 48a and formed as a single unit.

[0090] The second extension portions 43b all extend in the front-rear direction and are spaced apart in the front-rear direction. Each second extension portion 43b connects the right ends of two first extension portions 43a that are adjacent in the front-rear direction. The second extension portions 43b, except for the frontmost and rearmost second extension portions 43b, are welded to and integrated with the aluminum tube 48a.

[0091] The multiple third extension portions 43c all extend in the front-rear direction and are spaced apart in the front-rear direction. The third extension portion 43c is disposed between the second extension portions 43b in the front-rear direction. The second extension portion 43b and the third extension portion 43c are spaced apart in the front-rear direction. The third extension portion 43c connects right ends of two first extension portions 43a that are adjacent in the front-rear direction. The multiple third extension portions 43c are welded to the aluminum tube 48a and are formed integrally therewith.

[0092] The plurality of connecting portions 43d connect the left ends of two first extending portions 43a adjacent to each other in the front-rear direction, and are welded and integrated with the aluminum tube 48a.

[0093] Of the two fourth extension portions 43e, the front fourth extension portion 43e extends rearward from the left end of the first extension portion 43a that is located most forward among the multiple first extension portions 43a. Also, the rear fourth extension portion 43e extends forward from the left end of the first extension portion 43a that is located most rearward among the multiple first extension portions 43a.

[0094] As shown in FIG. 4 , the first temperature sensor 44 is provided in the case 41 and is located between the two vaporizers 42. The first temperature sensor 44 is, for example, a thermocouple. The first temperature sensor 44 is thermally connected to the second extension portion 43b of the shelf heater 43 via the heat transfer member 52. The first temperature sensor 44 measures the temperature of the shelf heater 43. It can also be said that the first temperature sensor 44 measures the temperature of the heating and vaporization unit 36.

[0095] Opening 41da is a structure for pulling out various wires and pipes of sterilization apparatus 1 extending from inside heating / vaporization unit 36 ​​to the outside of heating / vaporization unit 36. For example, opening 41da is used for pulling out wires 53 of shelf heater 43 and pipes such as silicon tube 48b to the outside of heating / vaporization unit 36.

[0096] 8 is a cross-sectional view exemplarily illustrating a portion of a cross section taken along line VIII-VIII in FIG. 4. As shown in FIG. 8, the heat transfer member 52 has contact portions 52a and 52b. The contact portion 52a is a concave surface. The shelf heater 43 is placed in the contact portion 52a, and the contact portion 52a is in contact with the shelf heater 43. The contact portion 52b is a concave surface. The first temperature sensor 44 is placed in the contact portion 52b, and the contact portion 52b is in contact with the first temperature sensor 44. The heat transfer member 52 is made of, for example, aluminum.

[0097] Here, the specific heat of each of the shelf heater 43, two plates 45, 46, and 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 sterilization chamber 11. In other words, the specific heat of the heating / vaporizing unit 36 ​​as a whole is lower than that of the sterilization chamber 11.

[0098] 1 has an input function for accepting operations from the user and a display function for displaying images. For example, operation unit 13 is a touch panel display that combines input and display functions. Operation unit 13 accepts, for example, an operation to start sterilization of object 100 to be sterilized.

[0099] The operation unit 13 displays buttons corresponding to various modes, which will be described later. The start operation is, for example, a touch operation on the button. Note that the operation unit 13 is not limited to a display with a touch panel.

[0100] The control device 3 shown in Fig. 1 has a CPU (Central Processing Unit), a ROM (Read Only Memory), and a 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.

[0101] The control device 3 also controls the outer heater 25, the liquid phase pump 32, the concentrator 33, the solenoid valve 34, the shelf heater 43, the vacuum pump 37, and the solenoid valve 38. The control device 3 is also connected to a vacuum gauge 39, a second temperature sensor 49, and the like.

[0102] The second temperature sensor 49 is provided inside the sterilization chamber 11. The second temperature sensor 49 is, for example, a thermocouple.

[0103] The control device 3 controls the external heater 25 to heat the sterilization cabinet 11 regardless of whether a start operation is performed on the operation unit 13. In detail, the control device 3 causes the external heater 25 to heat while the power is on to the sterilization device 1. Based on the detection result of the second temperature sensor 49, the control device 3 controls the external heater 25 so that the temperature in the center of the sterilization cabinet 11, i.e., the sterilization chamber 11a, reaches a specified target temperature.

[0104] The set temperature inside the storage compartment 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. Note that the location measured by second temperature sensor 49 is preferably a location that is less susceptible to the heat generated by shelf heater 43, as shown in Figure 1.

[0105] Next, we will explain the operation of the sterilization apparatus 1. The following operation is controlled by the control device 3. Furthermore, during the following operation, the external heater 25 operates and heats the sterilization chamber 11a from outside the sterilization chamber 11a. With the solenoid valve 34 closed, the sterilization apparatus 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.

[0106] The sterilization apparatus 1 opens the solenoid valve 34 when the pressure in the sterilization chamber 11a drops to a specified pressure. This causes the sterilant coming out of the concentrator 33 to flow toward the sterilization chamber 11a and into each heating / vaporization unit 36 ​​via the distributor 35. In each heating / vaporization unit 36, the sterilant flows from the supply port 42b between the two plates 45, 46 and is heated by the shelf heater 43 between the two plates 45, 46.

[0107] 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 with the two plates 45, 46. At this time, the shelf heater 43 heats the sterilant, promoting its vaporization. As a result, the sterilant instantly evaporates between the two plates 45, 46 up to the saturated vapor pressure. In other words, the sterilant evaporates between the two plates 45, 46.

[0108] This prevents the time lag between the vaporization of water molecules in the hydrogen peroxide solution and the vaporization of hydrogen peroxide molecules.The ratio of hydrogen peroxide to water in the vaporized sterilant (gas) is 60% hydrogen peroxide and 40% water, or a value close to that.

[0109] Immediately after vaporization, the sterilant is released from the multiple holes 45a toward the objects 100 placed on the main shelf 23. As described above, a certain pressure difference occurs during this process, so even if the objects 100 are wrapped in packaging, the sterilant penetrates into the packaging. Therefore, the objects 100 are sterilized even while the vaporized sterilant becomes uniform.

[0110] Meanwhile, vaporized sterilant that is not released from the multiple holes 45a flows out from outlet 42c into the sterilization chamber 11a outside the two plates 45, 46. The gaseous sterilant that enters the sterilization chamber 11a flows upward and comes into contact with the objects 100 to be sterilized placed on the main shelf 23. This sterilizes the objects 100 to be sterilized.

[0111] In this way, the sterilant is vaporized in vaporizer 42 directly below main shelf 23, and the vaporized sterilant reaches items 100 to be sterilized on main shelf 23 as described above. Therefore, the sterilant vaporized in vaporizer 42 can reach items 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 items 100 to be sterilized is likely to be maintained at or near 60% hydrogen peroxide and 40% water.

[0112] At this time, the shelf heater 43 heats (warms) the objects to be sterilized 100. That is, the shelf heater 43 heats the objects to be sterilized 100 when the sterilizing agent supply unit 12 is supplying the sterilizing agent to the sterilization chamber 11a.

[0113] Specifically, shelf heater 43 uses radiant heat to heat (warm) objects to be sterilized 100. Shelf heater 43 is controlled by control device 3 so that the temperature inside case 41 detected by first temperature sensor 44 is maintained at a predetermined temperature (for example, 55°C ± 5%).

[0114] As an example, shelf heater 43 is controlled so that the temperature of case 41 is a predetermined temperature during the sterilization process or heating (warming), and is controlled so that the temperature of case 41 is 55°C during standby (when sterilized). This standby temperature is the same as the temperature at a location relatively far from case 41 within sterilization chamber 11a.

[0115] 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.

[0116] When such a hydrogen peroxide solution vaporizes, the water vaporizes first, followed by the hydrogen peroxide, at a high rate. This is simply due to the difference in molecular mass (H2O = 18, H2O2 = 34), and this tendency remains the same whether the evaporation is by vacuum or thermal evaporation. This tendency results in the water vaporizing early in the evaporation of the hydrogen peroxide solution, followed by the hydrogen peroxide vaporizing later.

[0117] For this reason, when sterilizing the object 100, the water that is vaporized first tends to reach the object 100 first, forming a water film, and the hydrogen peroxide will reach the object 100 later. In this case, the hydrogen peroxide that reaches the object 100 is diluted by the water film that reached the object 100 first, which may make it difficult to achieve a significant sterilization effect.

[0118] In contrast, in this embodiment, as described above, the sterilant is vaporized instantly between the two plates 45, 46, which reduces the time difference between the vaporization of water and hydrogen peroxide in the hydrogen peroxide solution, and tends to reduce the difference in the time it takes for the hydrogen peroxide and water to reach the object 100. This tends to increase the sterilization effect of the hydrogen peroxide.

[0119] Next, we will explain the vaporization phenomenon of hydrogen peroxide solution. First, we will explain the vaporization phenomenon when an evaporating dish heated to about 80°C is placed under a vacuum of about 100 Pa and a few milliliters of 60% hydrogen peroxide solution is dropped onto the evaporating dish.

[0120] In this case, when hydrogen peroxide solution is dropped into an evaporating dish, it may be thought that the hydrogen peroxide solution will evaporate instantly, but in reality, like water droplets dropped onto an object such as a frying pan, a few milliliters of hydrogen peroxide solution will continue to splash and dance, gradually dividing and reducing in volume until it finally evaporates completely.

[0121] If the 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%. It is also confirmed that the hydrogen peroxide concentration is higher in the middle stage than in the early stage, and higher in the later stage than in the middle stage.

[0122] This means that water molecules evaporate first over time from the heated hydrogen peroxide solution, and the reason for this is molecular weight. The smaller the molecular weight, the easier it is to vibrate and evaporate, so it is thought that water molecules evaporate before hydrogen peroxide molecules. This tendency in the order of evaporation is thought to be unavoidable because it is thought to be caused by molecular weight, but if the evaporation phenomenon itself is completed in a very short time, the order of evaporation can be considered to be virtually negligible.

[0123] In this embodiment, based on the above idea, two plates 45, 46 are provided as described above, and the aqueous hydrogen peroxide solution is instantaneously vaporized between these plates 45, 46. In addition, by providing multiple holes 45a in plate 45, it is possible to further improve the sterilization efficiency.

[0124] As explained above, the sterilization apparatus 1 of this embodiment comprises a sterilization chamber 11a that contains the objects to be sterilized 100, a main shelf 23 that is contained in the sterilization chamber 11a and on which the objects to be sterilized are placed, two plates 45, 46 that are positioned below the main shelf 23 in the vertical direction of the sterilization chamber 11a and that face each other in the vertical direction of the sterilization chamber 11a with a gap between them, and a groove (45b or 46d) that is provided along the vicinity of both ends of at least one of the two plates 45, 46 in the width direction of the sterilization chamber 11a.

[0125] With this configuration, even if the evaporation rate slows down due to the condition of the sterilization apparatus 1 or other factors, causing the sterilant to diffuse as a liquid, the liquid sterilant will be trapped in the grooves (45b or 46d) and will lose its diffusing power. This prevents the liquid sterilant from being pushed out by the vaporized sterilant and sprayed into the sterilization chamber 11a. In other words, the sterilization apparatus 1 of this embodiment can prevent the liquid sterilant from spraying into the sterilization chamber.

[0126] Furthermore, by providing grooves (45b and 46d) on both of the two plates 45, the diffusion force of the liquid sterilant can be further suppressed.

[0127] The sterilization apparatus 1 according to this embodiment also has a plurality of holes 45a provided along the vicinity of both ends in the width direction of the plate 45, penetrating the plate 45 and connecting to the space between the two plates 45, .

[0128] As a result, as the vaporized sterilant becomes uniform, it is released vertically into the sterilization chamber 11a from the multiple holes 45a. Because the two plates 45, 46 are located below the main shelf 23 on which the objects 100 are placed, the vaporized sterilant is released directly onto the objects 100. Releasing the vaporized sterilant directly onto the objects 100 creates a pressure difference between the inside and outside of the packaging material, allowing the vaporized sterilant to penetrate into the packaging material even when the objects 100 are packaged in a packaging material such as nonwoven fabric. In other words, the sterilization apparatus 1 according to this embodiment can sterilize the objects 100 even before the vaporized sterilant becomes uniform, thereby improving sterilization efficiency. Furthermore, even if the liquid sterilant spreads due to a decrease in evaporation rate or the like, the presence of multiple holes 45a allows some of the vaporized sterilant to move into the sterilization chamber 11a, thereby weakening the power of the vaporized sterilant to spread the liquid sterilant, thereby reducing the possibility of the liquid sterilant being sprayed into the sterilization chamber 11a due to the diffusion force of the vaporized sterilant.

[0129] According to at least one of the embodiments described above, it is possible to prevent the liquid sterilant from being sprayed into the sterilization chamber.

[0130] 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. [Explanation of symbols]

[0131] 1... Sterilizer, 3... Control device, 11... Sterilization storage, 11a... Sterilization room, 23... Main shelf, 33... Concentrator, 42b... Supply port, 42c... Outlet, 43... Shelf heater, 45, 46... Board, 45a... Hole, 45b, 46d... Groove, 100... Object to be sterilized.

Claims

1. A sterilization room, a shelf housed in the sterilization chamber on which items to be sterilized are placed; a pressure reducing section that vaporizes the sterilant by reducing the pressure inside the sterilization chamber; a heating unit accommodated in the sterilization chamber and configured to heat the sterilant supplied to the sterilization chamber; two plates arranged below the shelf in the sterilization chamber and facing each other in the vertical direction of the sterilization chamber with a gap therebetween; a supply unit provided between the two plates and configured to supply the sterilant in liquid form between the two plates; Equipped with The two plates have: A groove is formed on a surface of at least one of the two plates facing the other plate, the groove being located near both ends in a width direction of the sterilization chamber that intersects with the up-down direction. Sterilization equipment.

2. The two plates have: The grooves are formed on both of the two plates, on the surfaces facing each other.

10. The sterilization device of claim 1.

3. The two plates have: The upper plate, which is located at the upper side of the sterilization chamber, of the two plates has at least one hole formed near each end of the width direction of the sterilization chamber, penetrating the upper plate in the up-down direction.

10. The sterilization device of claim 1.

4. The two plates have: The groove is formed at least in the upper plate, An upper opening of the hole in the vertical direction is located above the groove.

4. The sterilization apparatus according to claim 3.

5. The upper plate has: a plurality of holes of approximately the same size are formed near both ends of the upper plate in the width direction, and are spaced at approximately equal intervals in the front-rear direction of the sterilization chamber, which intersects with the up-down direction and the width direction; 4. The sterilization apparatus according to claim 3.

6. Both ends of the two plates in the width direction of the sterilization chamber are sealed by sealing members that seal both ends of the space between the two plates in the width direction, and fasteners that fasten the two plates to each other, The two plates have: the groove is formed in the vicinity of the portion sealed by the sealing member and substantially parallel to the portion; 6. A sterilization apparatus according to any one of claims 1 to 5.

7. In the two plates, When the sterilant supplied between the two plates is vaporized, the sterilant diffuses out of the gap between the two plates from a position in the supply section that is spaced apart from the position where the sterilant flows out between the two plates in the front-to-rear direction of the sterilization chamber, which intersects with the vertical direction and the width direction.

6. A sterilization apparatus according to any one of claims 1 to 5.

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