Decontamination mechanism

Abstract

To provide a decontamination mechanism that enables sufficient distribution of decontamination gas inside a device to be decontaminated during a decontamination operation, ensuring superior decontamination effects.SOLUTION: A decontamination mechanism A includes, alongside a safety cabinet B, a decontamination gas supply unit 2, a gas dispersion unit 3, a dispersion suction unit 4, a recovery device 5, and an air pump 6. Additionally, the decontamination mechanism A is equipped with a gas circulation path 7. Along the gas circulation path 7, a pressure flow meter 8a, a needle valve 9a, the recovery device 5, the air pump 6, a pressure flow meter 8b, and a needle valve 9b are provided.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] This invention relates to a decontamination mechanism. More specifically, it relates to a decontamination mechanism that ensures that decontamination gas is sufficiently distributed inside the equipment being decontaminated, thereby achieving an excellent decontamination effect. [Background technology]

[0002] Decontamination using decontamination gases is carried out to protect inspectors from infection during periodic inspections of safety cabinets and to decontaminate equipment, including workspaces such as isolators used for animal experiments.

[0003] Furthermore, formaldehyde, chlorine dioxide, peracetic acid, and hydrogen peroxide are commonly used as gases for decontamination.

[0004] For example, in the decontamination of safety cabinets using formaldehyde, the cabinet's exhaust vents and front openings are sealed with plastic film or duct tape to prevent the decontamination gas from leaking outside the equipment.

[0005] In addition, a blower is installed inside the cabinet, and when decontamination gas is generated, the blower is operated to promote the diffusion of the decontamination gas within the equipment.

[0006] Furthermore, if simply installing a blower inside the cabinet is insufficient, it is recommended to install an additional blower outside the cabinet to create a circulation path that circulates the decontamination gas downstream (secondary) of the exhaust filter under the workbench (see, for example, Non-Patent Document 1). [Prior art documents] [Non-patent literature]

[0007] [Non-Patent Document 1] "JIS K 3800 2021 Class II Cabinets for Biohazard Countermeasures," 1st edition, published by the Japanese Standards Association, July 20, 2021, Annex B (Reference) Decontamination and Evaluation of Decontamination Methods [Overview of the project] [Problems that the invention aims to solve]

[0008] However, in actual decontamination work, because formaldehyde is a carcinogen, there are concerns that decontamination gases may leak during the process. As a result, decontamination is carried out by simply sealing exhaust vents with plastic film or similar materials, without installing blowers inside or outside the cabinets.

[0009] As a result, the decontamination gas did not reach areas inside the safety cabinet that were difficult to access, leading to insufficient decontamination. Similar situations exist with other decontamination gases besides formaldehyde, due to concerns about the risks associated with leaks.

[0010] Furthermore, even if blowers were installed inside and outside the cabinet to create a circulation path for the decontamination gas, the blowers alone were insufficient to adequately distribute the decontamination gas to every corner of the safety cabinet.

[0011] This invention was conceived in view of the above points, and aims to provide a decontamination mechanism that ensures that decontamination gas is sufficiently distributed inside the equipment to be decontaminated during decontamination, thereby achieving an excellent decontamination effect. [Means for solving the problem]

[0012] To achieve the above objective, the present invention provides a decontamination mechanism for a predetermined device having a main body with a working space formed inside, and an exhaust filter that sterilizes the air in the working space before exhausting it to the outside of the main body from an exhaust section, the mechanism comprising: a decontamination gas supply path that supplies decontamination gas supplied from outside the main body toward an introduction space formed inside the main body and communicating with the working space; a gas dispersion section which is a cylindrical body arranged in the introduction space and connected to the decontamination gas supply path, with a plurality of holes formed on its outer surface; a closing plate which is a plate-like body that closes the exhaust section, with a plurality of ventilation sections formed through the plate-like body; and the closing plate The apparatus comprises an umbrella-shaped body covering an area in which multiple ventilation portions are formed, the end of which is connected to the edge of the closing plate, and a lid portion having an opening at its top; a gas circulation path connecting the opening to a supply port formed in the main body and communicating with the work space, forming a gas flow path; an air pump provided on the gas circulation path for circulating gas between the inside of the main body and the gas circulation path; a dehumidification unit provided on the gas circulation path for dehumidifying the air in the work space before or after the decontamination; and a recovery unit provided on the gas circulation path for recovering the decontamination gas from the air in the work space that has been exposed to the decontamination gas for a certain period of time.

[0013] Here, the decontamination gas supply path supplies decontamination gas supplied from outside the main body towards an introduction space formed inside the main body and communicating with the work space. This makes it possible to supply decontamination gas generated outside a predetermined device into the main body of the predetermined device and to deliver the decontamination gas to the work space.

[0014] Furthermore, the gas dispersion unit is a cylindrical body positioned in the introduction space and connected to the decontamination gas supply path. Multiple holes are formed on its outer surface, allowing the decontamination gas supplied from the decontamination gas supply path to be dispersed within the introduction space through these holes. In other words, since the decontamination gas can be supplied to multiple locations within the introduction space, it becomes easier to uniformly distribute the decontamination gas to every corner of the introduction space.

[0015] Further, there is a plate-like body that closes the exhaust part, a closing plate in which a plurality of ventilation parts penetrating the plate-like body are formed, and an umbrella-like body that covers a region where the plurality of ventilation parts of the closing plate are formed. The end part thereof is connected to the edge part of the closing plate, and by a lid part having an opening formed at the top, air can flow through the plurality of ventilation parts, and the air flow from the space between the exhaust filter and the exhaust part to the space covered by the umbrella-like body can be dispersed. As a result, even in the space between the exhaust filter and the exhaust part, the air flow can be dispersed, and it is possible to easily make the decontaminated gas evenly spread to every corner of the space.

[0016] Also, due to the opening being formed at the top of the lid part, it becomes possible to discharge air to the outside of the exhaust part through the opening.

[0017] Also, an opening is formed at the top of the lid part, and the gas circulation path connects the opening and a supply port formed in the main body and communicating with the working space, and by forming a gas flow path, a gas flow path connecting the exhaust part and the supply port can be constructed outside the main body.

[0018] Also, an air pump is provided on the gas circulation path, and by circulating gas between the inside of the main body and the gas circulation path, decontaminated gas can be circulated along the gas flow path composed of the supply port, the working space, the exhaust filter, and the exhaust part inside the main body and the gas circulation path.

[0019] Also, a dehumidifying part is provided on the gas circulation path, and by dehumidifying the air in the working space before or after decontamination, the working space to be decontaminated can be made into a low-humidity environment where the contents are not easily corroded. That is, for example, even when the member forming the working space is a metal member and the inside of the working space is in a high-humidity environment, by lowering the humidity inside the working space before or after decontamination and proceeding with the treatment, it is possible to prevent the contents from corroding.

[0020] In addition, the recovery unit is provided on the gas circulation path, and by recovering the decontamination gas from the air in the work space that has been exposed to the decontamination gas for a certain period of time, the concentration of the decontamination gas in the work space after decontamination can be reduced to a concentration that is safe for the human body and the like. That is, the work space after decontamination can be made into a safe environment that can be used by workers and the like.

[0021] In addition, when the gas dispersion part forms a closed path in plan view and divides the entire range of the closed path into a region close to the connection part and a region far from the connection part based on the connection part connected to the decontamination gas supply path, if the number of hole parts in the far region is formed to be larger than the number of hole parts in the near region, it becomes easier to discharge the decontamination gas from the region far from the connection part in the gas dispersion part, and furthermore, it becomes easier to uniformly disperse the decontamination gas into the introduction space. Here, the closed path means a shape in which, except for the hole parts, there is no break in the middle of the path and the one-week path is connected starting from the connection part.

[0022] In addition, when the size of the hole parts in the far region of the gas dispersion part is formed to be larger than the size of the hole parts in the near region, the discharge amount of the decontamination gas from each hole part in the region far from the connection part increases, and furthermore, it becomes easier to uniformly disperse the decontamination gas into the introduction space.

[0023] In addition, when the blocking plate is a corrosion-resistant porous plate and the ratio of the total area of the plurality of ventilation parts to the area of the plate-like body is 3% or more and within 8%, it becomes even easier to disperse the air flow in the space between the exhaust filter and the exhaust part, and it is possible to make the decontamination gas evenly spread to every corner of the same space.

[0024] On the other hand, if the closure plate is a corrosion-resistant porous plate and the ratio of the total area of ​​the multiple ventilation parts to the area of ​​the plate is less than 3%, the airflow in the ventilation parts may become poor, hindering the circulation of decontamination gas and potentially reducing the efficiency of decontamination. On the other hand, if the closure plate is a corrosion-resistant porous plate and the ratio of the total area of ​​the multiple ventilation parts to the area of ​​the plate exceeds 8%, the airflow passing through the closure plate is likely to become uneven, making it difficult to uniformly distribute the decontamination gas to every corner of the space between the exhaust filter and the exhaust section.

[0025] Furthermore, if the recovery device includes a dehumidification layer with a dehumidification section, a recovery layer with a recovery section, and a switching section on the gas circulation path that can switch between a flow path passing through the dehumidification layer and a flow path passing through the recovery layer, then both dehumidification before decontamination and recovery of decontamination gas after decontamination can be performed with a single recovery device installed in the gas circulation path, and the device can be made smaller.

[0026] Furthermore, the air pump can variably control the gas flow rate and is equipped with a first measuring unit located between the opening and the air pump in the gas circulation path to measure the gas flow rate and pressure, a first adjusting unit located between the opening and the air pump in the gas circulation path to adjust the gas flow rate and pressure, a second measuring unit located between the air pump and the supply port in the gas circulation path to measure the gas flow rate and pressure, and a second adjusting unit located between the air pump and the supply port in the gas circulation path to adjust the gas flow rate and pressure. By controlling the air pump, the first adjusting unit and the second adjusting unit based on the measurements from the first and second measuring units, the air pump can control the gas flow rate to efficiently circulate the decontamination gas in order to maintain a uniform pressure in the work space. In addition, it becomes easier to maintain negative pressure in the work space, which can suppress leakage of decontamination gas caused by the space becoming positive pressure.

[0027] Furthermore, if the air pump controls the gas flow rate based on the differential pressure, which is the difference between the gas pressure flowing between the opening in the gas circulation path and the air pump, and the gas pressure flowing between the air pump and the supply port in the gas circulation path, the air pump can control the gas flow rate to efficiently circulate the decontamination gas. In addition, it becomes easier to maintain negative pressure in the work space, which can suppress leakage of decontamination gas caused by the space becoming positive pressure.

[0028] Furthermore, if the dehumidifying section contains crystalline zeolite capable of adsorbing substances with a molecular diameter of less than 0.3 nm, it becomes possible to adsorb water molecules contained in the air in the workspace onto the crystalline zeolite, thereby achieving sufficient dehumidification.

[0029] Furthermore, if the specified device is a safety cabinet or an isolator for animal rearing, the decontamination gas can be thoroughly distributed to all parts inside the safety cabinet or isolator for animal rearing to ensure sufficient decontamination.

[0030] Furthermore, if the device is equipped with a gas discharge section that discharges the gas from inside the main body to the outside via a gas discharge path based on the measurement result of the internal-external differential pressure, which is the difference between the gas pressure inside the main body and the gas pressure outside the main body, then leakage of decontamination gas from inside the main body to the outside, which occurs when the internal pressure rises relative to the external pressure of the device, can be suppressed. This reduces the amount of decontamination gas exposed to the indoor space where the device is installed and to the workers performing the decontamination.

[0031] Furthermore, if the device is equipped with an exhaust recovery unit located on the gas discharge path to recover decontamination gas from the discharged gas, the concentration of decontamination gas in the gas discharged from inside the main unit can be reduced to a level safe for humans before being discharged to the outside. In other words, the indoor space in which the specified device is installed can be made into a safe environment that can be used by workers and others.

[0032] Furthermore, if the gas discharge unit discharges gas in such a way that it maintains a positive pressure of 1 hPa or less inside the main unit relative to the gas pressure outside the main unit, it can sufficiently suppress the leakage of decontamination gas from inside the main unit to the outside caused by an increase in the internal air pressure.

[0033] Furthermore, if the gas discharge unit discharges gas in such a way that it maintains a negative pressure inside the main unit relative to the external gas pressure, it can more effectively suppress the leakage of decontamination gas from inside the main unit to the outside, which would otherwise occur due to an increase in internal air pressure. [Effects of the Invention]

[0034] The decontamination mechanism according to the present invention ensures that the decontamination gas is thoroughly distributed throughout the inside of the equipment to be decontaminated during the decontamination process, resulting in an excellent decontamination effect. [Brief explanation of the drawing]

[0035] [Figure 1] This is a schematic diagram showing a decontamination mechanism which is a first embodiment of the present invention. [Figure 2] These are schematic plan views showing the shapes of the gas dispersion sections: (a) shows a rectangular gas dispersion section, (b) shows an annular gas dispersion section, and (c) shows a linear gas dispersion section. [Figure 3] (a) is a schematic diagram showing an example of a dispersion suction unit, and (b) is a schematic diagram showing another example of a dispersion suction unit. [Figure 4] This is a schematic diagram showing the recovery device and its surrounding structure. [Figure 5] This graph shows the changes in chlorine dioxide concentration and CT value over time in the decontamination workspace S in Example 1. [Figure 6] This is a flowchart illustrating an example of a decontamination process. [Figure 7] This flowchart shows another example of a decontamination method. [Figure 8](a) is a schematic side cross-sectional view showing the internal structure of the safety cabinet, and (b) is a schematic front cross-sectional view showing the internal structure of the safety cabinet. [Figure 9] This is a schematic diagram showing the location of the negative pressure plenum. [Figure 10] This figure shows the quantitative results of the residual chlorine content of aluminum. [Figure 11] This figure shows the quantitative results of the residual chlorine content in stainless steel. [Figure 12] This figure shows the quantitative results of the residual chlorine content in brass. [Figure 13] This figure shows the quantitative results of the residual chlorine content of lead. [Figure 14] This figure shows the quantitative results of the residual chlorine content of copper. [Figure 15] This figure shows the quantitative results of the residual chlorine content of iron. [Figure 16] This is a photographic diagram showing the observed degree of metal corrosion in copper, brass, aluminum, and stainless steel. [Figure 17] This is a photographic diagram showing the results of observations regarding the degree of metal corrosion of lead and iron. [Figure 18] This is a schematic diagram showing a decontamination mechanism, which is a second embodiment of the present invention. [Modes for carrying out the invention]

[0036] [First Embodiment of the Present Invention] The first embodiment of the present invention will be described below with reference to the drawings to facilitate understanding of the present invention. It should be noted that the following description is merely one example of a structure to which the present invention is applied, and the embodiments of the present invention are not limited to the structure described below.

[0037] Furthermore, in the following explanation, using Figure 1 as a reference, the upper part of the page will be referred to as "top" or "upper," and the lower part of the page will be referred to as "bottom" or "downward." Also, using Figure 1 as a reference, the front part of the page will be referred to as "front" or "forward," and the back part of the page will be referred to as "back" or "rear."

[0038] As shown in Figure 1, the decontamination mechanism A to which the present invention is applied is a mechanism for decontaminating a safety cabinet B having a working space S. The working space S referred to here corresponds to the working space in the claims of this application. The safety cabinet B referred to here corresponds to the predetermined device in the claims of this application.

[0039] Furthermore, Safety Cabinet B is a device that contains biological hazards such as pathogens and genetically modified organisms, thereby creating a safe working environment. For example, it is installed in laboratories of universities, research institutes, and medical institutions. The Safety Cabinet B described here is classified as Class IIA2.

[0040] First, we will explain the main structure of safety cabinet B, which is the target of decontamination, using Figures 8(a) and 8(b).

[0041] Safety cabinet B comprises a main body 10, an exhaust HEPA (High-Efficiency Particulate Air filter) filter 11, an intake HEPA filter 12, a workbench 13, and a front panel 14 (see Figure 8(a)). A workspace S is formed inside the main body 10, and the workbench 13 forms the bottom surface of the workspace S.

[0042] Furthermore, the safety cabinet B has an introduction space I located below the workbench 13, which is a space that is aerially connected to the work space S (see Figures 8(a) and 8(b)).

[0043] Furthermore, the positive pressure plenum 15 is a space covered by the exhaust HEPA filter 11 and the supply HEPA filter 12 (see Figures 8(a) and 8(b)). A blower 16 is also provided adjacent to the positive pressure plenum 15. In addition, the space labeled 17 in Figure 1 is the negative pressure plenum, and the introduction space I corresponds to a part of the negative pressure plenum 17. More specifically, the area with the dotted pattern in Figure 9 corresponds to the negative pressure plenum 17.

[0044] During normal use without decontamination, the safety cabinet B uses a fan to remove aerosols generated in the workspace S. These aerosols are then circulated back into the workspace S via a negative pressure plenum 17, with some being purified through an air supply HPEA filter 12, and others being purified through an exhaust HEPA filter 11 before being discharged into the environment (see Figures 8(a) and 8(b)).

[0045] Furthermore, during normal use, the air supplied from the blower 16 to the safety cabinet B passes through the positive pressure plenum 15, is purified through the supply air HEPA filter 12, and is then supplied to the workspace S. This ensures that the workspace S remains clean.

[0046] Furthermore, in safety cabinet B, the movement of contaminated aerosols into and out of the cabinet is prevented by balancing the airflow between the inflow velocity w1 and the clean air outlet velocity w2 (see Figure 8(a)). Also, the workspace S is 1m 3 ~5m 3 It is designed to be of a certain size.

[0047] Furthermore, the safety cabinet to be decontaminated in the decontamination mechanism of the present invention is not limited to the structure of safety cabinet B described above, but can be applied to various known safety cabinets classified as Class II. In addition, the decontamination mechanism of the present invention can also target animal breeding isolators in addition to safety cabinets.

[0048] Furthermore, in the safety cabinet B, instead of the exhaust HEPA filter 11 and the supply HEPA filter 12, it is also possible to use an exhaust ULPA (Ultra-Low Particulate Air filter) filter and a supply ULPA filter that can capture smaller particulate matter.

[0049] Next, we will explain decontamination mechanism A. The decontamination mechanism A shown in Figure 1 includes, in addition to the safety cabinet B having the structure described above, a decontamination gas supply unit 2, a gas dispersion unit 3, a dispersion suction unit 4, a recovery device 5, and an air pump 6.

[0050] Furthermore, the decontamination mechanism A is equipped with a gas circulation path 7, and along this gas circulation path 7 are a pressure flow meter 8a, a needle valve 9a, a recovery device 5, an air pump 6, a pressure flow meter 8b, and a needle valve 9b. In Figure 1, the decontamination gas is schematically represented by a cloud-like shape.

[0051] Here, the decontamination gas supply unit 2 is the part that generates decontamination gas and supplies it to the inside of the main body 10 of the safety cabinet B.

[0052] Furthermore, the gas dispersion unit 3 is a component that disperses the decontamination gas supplied from the decontamination gas supply unit 2 within the introduction space I of the safety cabinet B, thereby spreading the decontamination gas inside the main body 10.

[0053] Furthermore, the dispersed suction unit 4 is a component that spreads the flow of decontamination gas, which flows through the work space S and the inside of the main body 10 toward the exhaust HEPA filter 11, to every corner of the space connected to the exhaust HEPA filter 11 and the exhaust port B1 beyond it, and discharges it into the gas circulation path 7.

[0054] Furthermore, the recovery device 5 is a device that dehumidifies the air in the work space S before starting decontamination or after decontamination has been performed. In addition, the recovery device 5 is a device that recovers the decontamination gas contained in the air in the work space S after the completion of decontamination, and reduces the concentration of the decontamination gas to a safe level.

[0055] Furthermore, the air pump 6 is a component that generates a gas flow, circulating air between the inside of the main body 10 of the safety cabinet B and the gas circulation path 7.

[0056] Furthermore, the gas circulation path 7 is in aerial communication with the inside of the main body 10 of the safety cabinet B and is a gas flow path outside the safety cabinet B.

[0057] Furthermore, the pressure flow meter 8a is a component that measures the pressure and flow rate of the gas flowing between the dispersion suction unit 4 and the air pump 6 in the gas circulation path 7. In addition, the needle valve 9a is a component that adjusts the flow rate of the gas flowing between the dispersion suction unit 4 and the air pump 6 in the gas circulation path 7.

[0058] Furthermore, the pressure flow meter 8b is a component that measures the pressure and flow rate of the gas flowing between the air pump 6 and the supply port B2 (see Figure 1), which is formed in the main body 10 and communicates with the working space S, as part of the gas circulation path 7. The needle valve 9b is a component that adjusts the flow rate of the gas flowing between the air pump 6 and the supply port B2, as part of the gas circulation path 7.

[0059] Next, we will explain the detailed structure of each part.

[0060] [Decontamination Gas Supply Department] First, the decontamination gas supply unit 2 has a gas generation unit 20, a supply tube 21, and a recovery tube 22 (see Figure 1).

[0061] The gas generation unit 20, although not shown in the diagram, consists of an aeration tank, pump, chemical tank, waste liquid tank, etc., and is the part that generates decontamination gas. The decontamination gas can be appropriately selected from gases usable for decontamination, such as formaldehyde, chlorine dioxide, peracetic acid, and hydrogen peroxide. Furthermore, the gas generation unit 20 can be appropriately designed according to the type of decontamination gas used.

[0062] Furthermore, the supply tube 21 is a tube member that serves as a gas flow path for supplying the decontamination gas generated in the gas generation unit 20 to the gas dispersion unit 3 during the start-up process to bring the decontamination gas concentration to the target value within the work space S.

[0063] Furthermore, the recovery tube 22 is a tube member that serves as a gas flow path for recovering gas from the dispersion suction unit 4 towards the gas generation unit 20 during the start-up process. The gas that passes through the recovery tube 22 is used to generate decontamination gas in the gas generation unit 20.

[0064] [Gas dispersion section] As shown in Figure 2(a), the gas dispersion unit 3 forms a closed rectangular path in plan view and is connected to the supply tube 21 at the position of the connection part 30. In addition, the connection part 30 of the gas dispersion unit 3 is located at the front.

[0065] In other words, in the safety cabinet B, the region containing the connection portion 30 in the gas dispersion section 3 is located on the front side, and the region on the opposite side is located on the rear side. The connection portion 30 referred to here corresponds to the connection portion in the claims of this application.

[0066] Furthermore, in the gas dispersion section 3, multiple holes 31 are formed in the region close to the connection section 30, and multiple holes 32 are formed in the region farther from the connection section 30.

[0067] Furthermore, in the gas dispersion section 3, the number of pores 32 is greater than the number of pores 31. Also, the size of the pores in pores 32 is larger than the size of the pores in pores 31.

[0068] Note that in Figure 2(a), the number and size of holes 31 and 32 are shown schematically and do not reflect the actual number or size of the holes.

[0069] In the gas dispersion unit 3, the decontamination gas generated in the gas generation unit 20 is supplied from the supply tube 21, and the decontamination gas is discharged toward the introduction space I from multiple holes 31 or holes 32. Because the gas dispersion unit 3 discharges the decontamination gas from multiple holes 31 or holes 32, the gas can be uniformly dispersed within the space of the introduction space I.

[0070] Furthermore, in the gas dispersion section 3, the number of holes 32 located in the area farther from the connection section 30 is greater than the number of holes 31 located closer to the connection section 30, and the holes are also larger in size. As a result, it is easier to discharge the decontamination gas from the dispersion section 3 even at the rear of the introduction space I. Consequently, the decontamination gas can reach every corner of the introduction space I.

[0071] Furthermore, the shape of the gas dispersion section 3 is not limited to that shown in Figure 2(a). For example, the gas dispersion section 3a shown in Figure 2(b) forms a closed, annular path in plan view. In addition, the gas dispersion section 3a has multiple holes 31a formed in the region close to the connection section 30a, and multiple holes 32a formed in the region farther from the connection section 30.

[0072] Furthermore, the number of holes 32a is greater than the number of holes 31a, and the size of the holes in holes 32a is larger than the size of the holes in holes 31a. In this way, an annular gas dispersion portion 3a can be formed in plan view.

[0073] Furthermore, for example, the gas dispersion section 3b shown in Figure 2(c) has a linear path and multiple holes 33 are formed therein. Also, with respect to the connection section 30b, more holes 33 are formed in the outer region than in the central region. In this way, the gas dispersion section 3b can also be made linear in plan view.

[0074] Here, examples of the shape of the gas dispersion section 3 are shown in Figures 2(a) to 2(c). From the viewpoint of uniformly dispersing the decontamination gas in the introduction space I, the annular shape of the gas dispersion section 3a (Figure 2(b)) is preferable to the linear shape of the gas dispersion section 3b (Figure 2(c)), and the rectangular shape of the gas dispersion section 3 (Figure 2(a)) is even more preferable.

[0075] Furthermore, it is not necessarily required that the number of holes 32 in the gas dispersion section 3 be greater than the number of holes 31, nor is it necessary that the size of the holes in the holes 32 be larger than the size of the holes in the holes 31. However, as described above, it is preferable that the number of holes 32 in the gas dispersion section 3 be greater than the number of holes 31, and that the size of the holes in the holes 32 be larger than the size of the holes in the holes 31, in order to facilitate the discharge of decontamination gas from the dispersion section 3 even at the rear of the introduction space I, and to ensure that the decontamination gas reaches every corner of the introduction space I.

[0076] Although not shown in the diagram, an air circulator is installed inside the workspace S. This air circulator operates during the decontamination startup and exposure processes to disperse the decontamination gas within the workspace S.

[0077] [Dispersion suction section] As shown in Figure 3(a), the dispersion suction unit 4 has a closing plate 40 and a lid 41.

[0078] The closing plate 40 referred to here corresponds to the closing plate in the claims of this application. Also, the cover portion 41 referred to here corresponds to the cover portion in the claims of this application.

[0079] The sealing plate 40 is a plate-like body installed to block the exhaust port B1 of the safety cabinet B, and is made of corrosion-resistant polyvinyl chloride. The sealing plate 40 also has multiple uniformly formed ventilation openings 400 that penetrate the plate-like body. These ventilation openings 400 are circular holes.

[0080] Furthermore, a pyramidal lid portion 41 is provided on the upper part of the closing plate 40. The lower outer edge of the lid portion 41 is connected to the outer edge of the closing plate 40. As a result, a space S10 covered by the lid portion 41 is formed above the closing plate 40.

[0081] Furthermore, an opening 410 is formed at the top of the lid 41, and the lid 41 is connected to the gas circulation path 7 at the location of this opening 410. In other words, the space S10 covered by the lid 41 is aerially connected to the gas circulation path 7.

[0082] The ventilation portion 400 referred to here corresponds to the ventilation portion in the claims of this application. Also, the opening 410 referred to here corresponds to the opening in the claims of this application.

[0083] In this dispersed suction section 4, the air flows through multiple ventilation sections 400, thereby dispersing the airflow from the space between the exhaust HEPA filter 11 and the exhaust port B1 to the space S10 surrounded by the lid 41 and the closing plate 40.

[0084] This allows the airflow to be dispersed even in the space between the exhaust HEPA filter 11 and the exhaust port B1, making it easier to distribute the decontamination gas uniformly to every corner of that space.

[0085] In particular, the space between the exhaust HEPA filter 11 and the exhaust port B1 is a space where decontamination gas does not reach with conventional decontamination methods that only involve installing blowers inside and outside the cabinet, and is prone to yielding positive results in judgments using BI, which is an indicator of decontamination. Therefore, it is important to ensure that the decontamination gas reaches this area.

[0086] Furthermore, the multiple ventilation sections 400 formed in the closure plate 40 can also be formed as slit-shaped ventilation sections 400a (see Figure 3(b)). In the closure plate 40a shown in Figure 3(b), multiple slits penetrating the plate-like body are uniformly formed.

[0087] Furthermore, in the multiple ventilation sections 400 formed in the closure plate 40, it is preferable that the area of ​​all ventilation sections 400 combined, that is, the ratio of the area of ​​the open portion to the total area of ​​the closure plate 40, be set to 3% or more and 8% or less. By setting the ratio of the area of ​​the open portion in this way, it becomes easier to disperse the airflow in the space between the exhaust HEPA filter 11 and the exhaust port B1, and it becomes easier to distribute the decontamination gas uniformly to every corner of the space.

[0088] On the other hand, if the ratio of the total area of ​​the multiple ventilation sections 400 to the total area of ​​the closure plate 40 is less than 3%, the airflow in the ventilation sections 400 will be poor, hindering the circulation of the decontamination gas and potentially reducing the efficiency of decontamination. Conversely, if the ratio of the total area of ​​the multiple ventilation sections 400 to the total area of ​​the closure plate 40 exceeds 8%, the airflow passing through the closure plate 40 is likely to become uneven, making it difficult to uniformly distribute the decontamination gas to every corner of the space between the exhaust HEPA filter 11 and the exhaust port B1.

[0089] Furthermore, the closing plate 40 does not necessarily have to be made of corrosion-resistant polyvinyl chloride. However, it is preferable that a corrosion-resistant material be used.

[0090] [Recovery device] As shown in Figure 4, the recovery device 5 has three layers inside: an upper layer 50 filled with crystalline zeolite, a middle layer 51 filled with activated carbon, and a lower layer 52 that is not filled with crystalline zeolite or activated carbon.

[0091] The recovery device 5 referred to here is the component corresponding to the recovery device in the claims of this application. Furthermore, the upper layer 50 referred to here corresponds to the dehumidifying layer in the claim of this application, and the middle layer 51 referred to here corresponds to the recovery layer in the claim of this application. Furthermore, the crystalline zeolite referred to here is the component that corresponds to the crystalline zeolite in the claim of this application.

[0092] Furthermore, the recovery device 5 is located on the gas circulation path 7, and the partially branched gas circulation path 7 is connected to three layers of the recovery device 5: the upper layer 50, the middle layer 51, and the lower layer 52 (see Figure 4).

[0093] Furthermore, the gas circulation path 7 is provided with switching valves 500, 510, and 520 upstream and downstream of each layer, respectively, allowing the gas flow path to be switched. Note that the switching valves 500 and 510 referred to here are the components corresponding to the switching parts in the claims of this application.

[0094] Although not shown in the diagram, pre-filters are provided above and below the upper layer 50 and the middle layer 51 to prevent the crystalline zeolite or activated carbon from moving due to the gas flow.

[0095] Here, the upper layer 50, which is filled with crystalline zeolite, is the part that allows air from the work space S to pass through before or after the work space S has been exposed to decontamination gas and the decontamination gas has been recovered in the middle layer 51, thereby dehumidifying the work space S by adsorbing water molecules contained in the air onto the crystalline zeolite.

[0096] Furthermore, the middle layer 51, which is filled with activated carbon, is a section for exposing the work space S to decontamination gas, passing the air from the work space S through it, adsorbing the decontamination gas onto the activated carbon, and then recovering it.

[0097] Furthermore, the lower layer 52, which is not filled with crystalline zeolite and activated carbon, is the part that becomes the gas flow path of the gas circulation path 7 in the recovery device 5 during decontamination.

[0098] Thus, the recovery device 5 is a component that performs two processes: dehumidification by passing the air inside the work space S through it, either before or after decontamination, and recovery of the gas after the work space S has been exposed to the decontamination gas.

[0099] Furthermore, the crystalline zeolite filling the upper layer 50 is a crystalline zeolite capable of adsorbing substances with a molecular diameter of less than 0.3 nm, and is an aluminosilicate crystalline material. It has fine pores in its crystal structure, allowing it to selectively adsorb water molecules. In addition, this crystalline zeolite is capable of adsorbing 20% ​​by weight of water molecules (water vapor).

[0100] Furthermore, even after crystalline zeolite has reached its water molecule adsorption capacity saturation, its adsorption capacity can be restored by collecting, washing, and drying it.

[0101] Here, the amount of crystalline zeolite to fill the upper layer 50 can be set as appropriate. However, the volume of the working space S is 1 m³ 3 ~5m 3 Therefore, before commencing decontamination, the air in the work space S within the said volume range should be set to a relative humidity of less than 32% and an absolute humidity of 3.0 g / m³. 3 To maintain a low humidity environment, the amount of crystalline zeolite filled in the upper layer 50 is preferably 50g to 2000g, more preferably 100 to 1500g, and even more preferably set to 200g to 1000g.

[0102] Furthermore, the activated carbon filled in the middle layer 51 is granular activated carbon consisting of pelletized activated carbon and irregularly shaped crushed carbon, and the middle layer 51 is constructed by filling a mold with granular activated carbon.

[0103] Here, the activated carbon that is filled into the middle layer 51 is not particularly limited in shape or size, as long as it can adsorb and recover the decontamination gas.

[0104] Furthermore, the amount of activated carbon filled into the molding frame in the middle layer 51 can be set as appropriate. However, the volume of the working space S is 1 m³ 3 ~5m 3Therefore, considering that the volume range is exposed to the decontamination gas efficiently in a short time, and that the activated carbon is used approximately 1 to 3 times, the amount of activated carbon filled in the middle layer 51 is preferably 50g to 5000g, more preferably 100 to 2000g, and even more preferably set to 200g to 1200g.

[0105] Furthermore, it is not necessarily required that the recovery device 5 be formed with an upper layer 50 filled with crystalline zeolite and a middle layer 51 filled with activated carbon. A dehumidifying member filled with crystalline zeolite and a decontamination gas recovery member filled with activated carbon may be provided separately on the gas circulation path 7. However, it is preferable to have a recovery device 5 with an upper layer 50 filled with crystalline zeolite and a middle layer 51 filled with activated carbon, as this makes maintenance easier, as maintenance only requires replacing the recovery device 5.

[0106] [Air pump] As described above, the air pump 6 is a component that generates a gas flow, circulating air between the inside of the main body 10 of the safety cabinet B and the gas circulation path 7. This air pump 6 generates a gas flow during each of the following processes: dehumidification before the start of decontamination (or dehumidification after decontamination and recovery), the start-up process before exposure to decontamination gas, exposure to decontamination gas, and recovery after decontamination.

[0107] Furthermore, the air pump 6 has a fan motor that can variably control the flow rate of the gas, and is a device that ensures the optimal airflow to set the humidity and decontamination gas concentration in the work space S to the desired set values.

[0108] Furthermore, the decontamination mechanism A has a control device (not shown) that controls the operation of the air pump 6, needle valve 9a, and needle valve 9b based on the measurements of the pressure flow meter 8a and the pressure flow meter 8b. In addition, the control of each component of this control device makes it possible to adjust and maintain a uniform pressure within the working space S.

[0109] Furthermore, in decontamination mechanism A, protective film is attached to various exhaust vents and openings of the equipment to prevent decontamination gas from leaking outside safety cabinet B (not shown).

[0110] Furthermore, a concentration measurement mechanism is provided inside the workspace S to measure the relative humidity, absolute humidity, and concentration of decontamination gases in the internal environment of the workspace S (not shown). Note that a known device can be used for the concentration measurement mechanism, and a detailed explanation is omitted in this document.

[0111] Here, it is not necessarily required to install pressure flow meters 8a and 8b on the gas circulation path 7 and control the operation of the air pump 6, needle valve 9a, and needle valve 9b based on their respective measurements. For example, it is possible to measure the differential pressure between a position upstream of the air pump 6 and a position downstream of the air pump 6 on the gas circulation path 7, and control the airflow rate of the air pump 6 so that the differential pressure becomes zero, thereby adjusting and maintaining a uniform pressure within the working space S. In this embodiment, it is sufficient to measure only the differential pressure upstream and downstream of the air pump 6, eliminating the need to install gas flow meters and needle valves.

[0112] Next, we will describe an example of the flow of a decontamination operation using the decontamination mechanism A to which the present invention is applied.

[0113] Figure 6 shows the main steps of an example of a decontamination method. As shown in Figure 6, the series of steps related to decontamination work includes a dehumidification step (S1), a start-up step (S2), an exposure step (S3), and a recovery and washing step (S4).

[0114] Here, the dehumidification process (S1) is a process of collecting water molecules contained in the air inside the work space S of the safety cabinet B and dehumidifying it before decontamination is performed on the work space S.

[0115] In this process, the air pump 6 is driven, and the air inside the working space S is sucked toward the recovery device 5 through the gas circulation path 7. Further, the sucked air opens the switching valve 500, closes the switching valves 510 and 520, and passes through the upper layer portion 50 of the recovery device 5.

[0116] When passing through this upper layer portion 50, the water molecules contained in the sucked air are adsorbed by the crystalline zeolite. As a result, the sucked air is dehumidified and returned to the inside of the working space S again.

[0117] Also, in this process, the temperature, relative humidity, and absolute humidity of the internal environment of the working space S are measured by the concentration measurement mechanism, and each measured value is monitored. In the dehumidification process (S1), in the air inside the working space S, the relative humidity is less than 32% and the absolute humidity is less than 3.0 g / m 3 Until it becomes less than, dehumidification is continuously performed. That is, the circulation of the gas through the air pump 6 and the gas circulation path 7 is performed until the target humidity is reached.

[0118] Also, in the air inside the working space S, when the relative humidity is less than 32% and the absolute humidity is less than 3.0 g / m 3 Until it becomes less than, the process proceeds to the next startup process (S2).

[0119] By this dehumidification process (S1), the inside of the working space S can be made into a low-humidity environment. Also, the detection of the values of the relative humidity and the absolute humidity, the end of the dehumidification process (S1) based on this, and the start of the startup process (S1) are automatically controlled by a sequencer (not shown).

[0120] Next, a decontamination gas is generated, and a startup process (S2) is performed to reach the target value concentration of the decontamination gas concentration inside the working space S.

[0121] In this startup process (S2), the gas generation unit 20 generates decontamination gas, which is then supplied from the supply tube 21 to the gas dispersion unit 3. Here, the amount of each chemical solution that will be used as raw material to bring the decontamination gas to the target concentration is determined in the gas generation unit 20, and each chemical solution is placed in its respective container.

[0122] Furthermore, during the startup process (S2), the decontamination gas is uniformly dispersed from the gas dispersion unit 3 toward the introduction space I. This allows the decontamination gas to reach every corner of the introduction space I. The decontamination gas also spreads from the introduction space I into the work space S.

[0123] Even within the workspace S, the decontamination gas is dispersed by the gas dispersion unit 3, making it easier for the decontamination gas to spread. Furthermore, the decontamination gas can be further dispersed by operating the air circulator installed inside the workspace S.

[0124] In addition, during the start-up process (S2), the air pump 6 is driven to create an airflow from the outlet B1 of the safety cabinet B towards the gas circulation path 7. Furthermore, in the recovery device 5, the switching valve 520 is opened, and the switching valves 500 and 510 are closed, allowing the gas to pass through the lower section 52 of the recovery device 5.

[0125] The air drawn in by the air pump 6 travels through the gas circulation path 7 to the supply port B2 and is returned to the interior of the work space S. In this way, a gas circulation path is formed inside and outside the safety cabinet B via the air pump 6 and the gas circulation path 7.

[0126] This makes it easier to distribute the decontamination gas throughout the workspace S, the supply air HEPA filter 12, the positive pressure plenum 15, the exhaust HEPA filter 11, and the space between the exhaust HEPA filter 11 and the outlet B1, even during the start-up process (S2).

[0127] Furthermore, when circulating air with the air pump 6, the control device controls the operation of the air pump 6, needle valve 9a, and needle valve 9b based on the measurements of the pressure flow meter 8a and the pressure flow meter 8b, thereby adjusting and maintaining a uniform pressure within the working space S.

[0128] Furthermore, during the startup process (S2), when circulating the gas via the air pump 6 and the gas circulation path 7, the dispersion suction unit 4 can spread the flow of decontamination gas that is flowing toward the exhaust HEPA filter 11 to every corner of the space connected to the exhaust HEPA filter 11 and the exhaust port B1 beyond it.

[0129] Furthermore, in the startup process (S2), the gas in the work space S is recovered by the gas generation unit 20 via the recovery tube 22, the decontamination gas is adsorbed onto activated carbon, and the resulting fresh air is used again to generate decontamination gas.

[0130] As a result, when aeration is performed in the gas generation unit 20 to generate decontamination gas, it is no longer necessary to introduce new air from the outside space, which prevents the sealed space from becoming positively pressurized and prevents the decontamination gas from leaking to the outside. In addition, because the gas is circulated, the concentration of the decontamination gas can be increased efficiently within the sealed space.

[0131] Furthermore, in this process, the concentration of decontamination gas inside the work space S is measured by a concentration measurement mechanism. This measurement of the decontamination gas concentration is performed automatically at set intervals.

[0132] Furthermore, during the startup process (S2), the generation and supply of decontamination gas continues until the concentration of decontamination gas inside the work space S increases and reaches the target concentration. The target concentration can be set as appropriate.

[0133] Furthermore, when the concentration of the decontamination gas in the air inside the workspace S reaches the target concentration, the operation of the gas generation unit 20 is stopped, and the process proceeds to the next exposure step (S3).

[0134] Next, with the supply of decontamination gas stopped, an exposure process (S3) is performed in which the work space S is exposed to the decontamination gas. In the exposure process (S3), with the introduced decontamination gas filling the work space S, the air pump 6 is driven, similar to the start-up process (S2), and the gas is circulated inside and outside the safety cabinet B via the gas circulation path 7.

[0135] In this process, the air circulator inside the workspace S is also operated to disperse the decontamination gas within the workspace S. Furthermore, the safety cabinet B is activated as needed.

[0136] Furthermore, during the exposure process (S3), the CT value is continuously calculated based on the concentration measurement by the concentration measurement mechanism while the introduced decontamination gas fills the work space S.

[0137] Furthermore, when the CT value is detected to be above a set threshold, the exposure process (S3) ends, and the process proceeds to the next recovery and washing process (S4).

[0138] In this exposure process (S3), decontamination gas is applied to the walls and top surface of the workbench 13 that make up the work space S, the introduction space I, the supply air HEPA filter 12, the positive pressure plenum 15, the exhaust HEPA filter 11, and the space between the exhaust HEPA filter 11 and the outlet B1, thereby reducing the number of microorganisms that adhere to these surfaces or float in the air.

[0139] Examples of microorganisms that can be sterilized and disinfected include bacteria, fungi, and viruses.

[0140] In this exposure process (S3), microorganisms can be effectively removed in a short time by applying a decontamination gas to the work space S.

[0141] Next, in the recovery and washing process (S4), the air inside the work space S is drawn in, and the decontamination gas contained in the air is adsorbed, thereby reducing the concentration of decontamination gas in the work space S to a level safe for human health.

[0142] In this recovery and cleaning process (S4), the air pump 6 is driven to draw air from inside the work space S towards the recovery device 5 via the gas circulation path 7.

[0143] In this process, the switching valve 500 is opened first, and the switching valves 510 and 520 are closed to allow air containing decontamination gas to pass through the upper part 50 of the recovery device 5.

[0144] Even if holes were to appear in the exhaust HEPA filter 11 and the supply HEPA filter 12, and the positive pressure plenum 15 were to become contaminated with pathogenic microorganisms or other contaminants, and these contaminants were to adhere to the crystalline zeolite filled in the upper part 51 of the recovery device 5 during the decontamination process (S1), the contaminants could be inactivated by flowing air containing decontamination gas from the work space S into the upper part 51.

[0145] Subsequently, the switching valve 510 is opened, and the switching valves 500 and 520 are closed to allow air to pass through the middle section 51 of the recovery device 5.

[0146] As the air passes through this intermediate layer 51, the decontamination gases contained in the aspirated air are adsorbed by the activated carbon. The air that has passed through the activated carbon is then returned to the interior of the work space S.

[0147] In addition, during this process, the concentration of decontamination gas inside the work space S is measured by a concentration measurement mechanism, and the measured value is monitored. In the recovery and washing process (S4), decontamination gas is continuously recovered from the air inside the work space S until the concentration of decontamination gas falls below a set level.

[0148] Furthermore, when the decontamination gas concentration in the air inside the workspace S falls below the set concentration, the recovery and washing process (S4) is terminated. At this point, the series of decontamination treatments for the workspace S is considered complete, and the safety cabinet B becomes usable.

[0149] Following the above procedure, a series of steps related to decontamination work using decontamination mechanism A are carried out.

[0150] Furthermore, Figure 7 illustrates another example of the flow of a decontamination operation using the decontamination mechanism A to which the present invention is applied.

[0151] Figure 7 shows another example of a decontamination method, which differs from the method shown in Figure 6 above. In this method, the dehumidification process is not performed before the start-up process, but rather after the exposure process and the recovery / washing process are completed.

[0152] The series of steps shown in Figure 7 includes a start-up step (S5), an exposure step (S6), a recovery and washing step (S7), and a dehumidification step (S8). In the following explanation, we will omit descriptions of parts that are common to the flow shown in Figure 6 above, and focus on the differences.

[0153] First, the startup process (S5) and exposure process (S6) are almost the same as the startup process (S2) and exposure process (S3) described above. The difference is that, since there is no prior dehumidification process (S1), the relative humidity of the internal environment of the work space S is at or above the room humidity, for example, the relative humidity is 60% to 90%.

[0154] Next, in the recovery and washing process (S7), the air pump 6 is driven to draw air from inside the work space S to the recovery device 5 via the gas circulation path 7. The drawn air is then passed through the middle section 51 of the recovery device 5 by opening the switching valve 510 and closing the switching valves 500 and 520.

[0155] As the air passes through this intermediate layer 51, the decontamination gases contained in the aspirated air are adsorbed by the activated carbon. The air that has passed through the activated carbon is then returned to the interior of the work space S.

[0156] In addition, during this process, the concentration of decontamination gas inside the work space S is measured by a concentration measurement mechanism, and the measured value is monitored. In the recovery and washing process (S7), decontamination gas is continuously recovered from the air inside the work space S until the concentration of decontamination gas falls below a set level.

[0157] Furthermore, when the concentration of decontamination gas in the air inside the workspace S falls below the set concentration, the recovery and washing process (S7) is terminated.

[0158] Next, in the dehumidification process (S8), the working space S of the safety cabinet B is dehumidified by collecting water molecules contained in the air inside the working space S.

[0159] In this process, the air pump 6 is driven to draw air from inside the work space S to the recovery device 5 via the gas circulation path 7. The drawn air is then passed through the upper part 50 of the recovery device 5 by opening the switching valve 500 and closing the switching valves 510 and 520.

[0160] As the air passes through this upper layer 50, water molecules contained in the aspirated air are adsorbed onto the crystalline zeolite. As a result, the aspirated air is dehumidified and returned to the interior of the workspace S.

[0161] In addition, during this process, the temperature, relative humidity, and absolute humidity of the internal environment of the workspace S are measured by a concentration measurement mechanism, and each measured value is monitored. In the dehumidification process (S8), the absolute humidity of the air inside the workspace S is reduced to 6-10 g / m³. 3 Maintain the following conditions and keep the workspace S in a low-humidity state for approximately 10-30 minutes.

[0162] Thus, by performing a dehumidification step (S8) to dehumidify the workspace S after the exposure step (S6) and the recovery and washing step (S7), the workspace S can be made into a low-humidity environment where the contents are less likely to corrode.

[0163] Then, once the dehumidification process (S8) is complete, the series of decontamination treatments for the workspace S is finished, and the safety cabinet B becomes usable.

[0164] The above procedure allows for the execution of a series of steps related to decontamination work using decontamination mechanism A.

[0165] By using the decontamination mechanism A to which the present invention is applied, the decontamination gas can be sufficiently distributed inside the device of the safety cabinet B.

[0166] In particular, the decontamination gas can be distributed to every corner, not only within the workspace S, but also around the ends and periphery of the exhaust HEPA filter 11, the positive pressure plenum 15, around the ends and periphery of the supply HEPA filter 12, and in the introduction space I located below the workbench 13, thereby achieving a sufficient decontamination effect.

[0167] As described above, the decontamination mechanism of the present invention ensures that the decontamination gas is sufficiently distributed throughout the inside of the equipment to be decontaminated during the decontamination process, resulting in an excellent decontamination effect.

[0168] [Second embodiment of the present invention] A second embodiment of the present invention will now be described. The main difference between the decontamination mechanism A2 in the second embodiment of the present invention and the first embodiment described above is that it has a mechanism for discharging gas from inside the safety cabinet to the outside based on the difference between the air pressure inside the safety cabinet (hereinafter referred to as "internal pressure") and the atmospheric pressure in the room space in which the safety cabinet is installed (hereinafter referred to as "atmospheric pressure"). Furthermore, the decontamination mechanism A2 uses chlorine dioxide as the decontamination gas.

[0169] The internal structure of safety cabinet B3 in decontamination mechanism A2 is the same as the internal structure of safety cabinet B1 in the first embodiment of the present invention described above, and therefore a detailed explanation is omitted. Furthermore, the following explanation will focus on the differences from the first embodiment of the present invention.

[0170] As shown in Figure 18, the decontamination mechanism A2 is connected to the inside of the main body of the safety cabinet B3 and has a gas discharge path 101 that can discharge the air inside the main body to the outside of the main body.

[0171] Furthermore, an internal pressure exhaust pump 103 and an internal pressure exhaust filter 104 are provided on the gas discharge path 101.

[0172] This internal pressure exhaust pump 103 is a component that transports air when discharging gas from the inside to the outside of the main body of the safety cabinet B3.

[0173] Furthermore, the internal pressure exhaust filter 104 is a component that adsorbs and recovers chlorine dioxide (decontamination gas) contained in the gas discharged to the outside of the main body of the safety cabinet B3, and is constructed by filling it with activated carbon.

[0174] Furthermore, a cabinet internal pressure sensor 100 for measuring internal pressure is installed inside the main body of the safety cabinet B3. In addition, an atmospheric pressure sensor 102 for measuring atmospheric pressure is installed in the room space in which the safety cabinet B3 is installed.

[0175] Furthermore, the decontamination mechanism A2, via a control unit (not shown), observes the difference between the internal pressure of the safety cabinet and atmospheric pressure in real time and controls the operation of the internal pressure exhaust pump 103. This control unit controls the operation of the internal pressure exhaust pump 103 so that the internal pressure of the safety cabinet is maintained at a negative pressure relative to atmospheric pressure.

[0176] The gas discharge path 101 referred to here corresponds to the gas discharge path in the claims of this application. Furthermore, the control unit referred to here corresponds to the gas discharge unit in the claims of this application, and the difference between the internal pressure of the safety cabinet and atmospheric pressure corresponds to the internal-external differential pressure in the claims of this application.

[0177] Furthermore, the internal pressure exhaust filter 104 referred to here is the component corresponding to the exhaust recovery unit in the claims of this application.

[0178] Here, the control unit does not necessarily need to control the drive of the internal pressure exhaust pump 103 so that the internal pressure of the safety cabinet is maintained at a negative pressure relative to atmospheric pressure. For example, it is also possible to set the internal pressure of the safety cabinet to be maintained at a positive pressure of 1 hPa or less relative to atmospheric pressure. However, it is preferable for the control unit to control the drive of the internal pressure exhaust pump 103 so that the internal pressure of the safety cabinet is maintained at a negative pressure relative to atmospheric pressure, in order to sufficiently suppress the leakage of decontamination gas from the inside of the main body to the outside, which occurs when decontamination gas is supplied into the inside of the safety cabinet B3 and the internal pressure rises.

[0179] Furthermore, the decontamination mechanism A2 has a chlorine dioxide gas measuring unit 111 located outside the main body of the safety cabinet B3 (see Figure 18). The chlorine dioxide gas measuring unit 111 also has a chlorine dioxide gas measuring optical path 115 and an optical path pressure sensor 114.

[0180] The chlorine dioxide gas measuring optical path 115 is a component that measures the concentration of chlorine dioxide gas contained in the gas sample taken from inside the main body of the safety cabinet B3. The optical path pressure sensor 114 is a component that measures the pressure of the gas in which the concentration of chlorine dioxide gas has been measured.

[0181] Furthermore, the chlorine dioxide gas measuring unit 111 is located on a path composed of an internal air collection tube 220 that transfers gas inside the main body of the safety cabinet B3, and an internal air return tube 110 that transfers the gas that has passed through the chlorine dioxide gas measuring optical path 115 back into the main body of the safety cabinet B3.

[0182] Furthermore, the internal air collection tube 220 is equipped with a flow control valve 113 to adjust the flow rate of gas passing through the chlorine dioxide gas measuring unit 111, and a measuring unit supply pump 112 to create the gas flow to the chlorine dioxide gas measuring unit 111.

[0183] In decontamination mechanism A2, the chlorine dioxide gas measurement unit 111 measures the concentration of chlorine dioxide gas in the gas inside the main body of safety cabinet B3 in real time.

[0184] Furthermore, the decontamination mechanism A2 has a gas circulation path 7A (see Figure 18). This gas circulation path 7A has the same function as the gas circulation path 7 described above. The gas circulation path 7A is equipped with a circulating blower 70 and a circulating pressure release valve 71.

[0185] Furthermore, the circulating fan 70 is a component that creates a gas flow, circulating air between the inside of the main body of the safety cabinet B3 and the gas circulation path 7A. The circulation pressure release valve 71 is a valve that adjusts the air pressure of the circulating fan 70.

[0186] Furthermore, the gas circulation path 7A is equipped with a dehumidifying filter 72 and a recovery filter 73.

[0187] Furthermore, the dehumidifying filter 72 is a component that, before exposing the working space of the safety cabinet B3 to chlorine dioxide, or after exposing the working space to chlorine dioxide and recovering the chlorine dioxide with the recovery filter 73, allows the air from the working space to pass through, adsorbing water molecules contained in the air onto the crystalline zeolite, thereby dehumidifying the working space.

[0188] Furthermore, the recovery filter 73 is filled with activated carbon and is used to recover chlorine dioxide after it has been exposed to the working space and the air from the working space has been passed through it, allowing the chlorine dioxide to be adsorbed onto the activated carbon.

[0189] Furthermore, the gas circulation path 7A is equipped with a filter activation switching valve 74, a dehumidifying filter switching valve 75, and a recovery filter switching valve 76.

[0190] Furthermore, the filter activation / deactivation valve 74 is a valve that switches the dehumidifying filter 72 and the recovery filter 73 on or off.

[0191] Furthermore, the dehumidifying filter switching valve 75 is a valve that switches whether the gas passes only through the dehumidifying filter 72 or through both the dehumidifying filter 72 and the recovery filter 73, enabling or disabling it.

[0192] Furthermore, the recovery filter switching valve 76 is a valve that switches the recovery filter 73 on or off.

[0193] Furthermore, the decontamination mechanism A2 has a gas generation unit 200 (see Figure 18). The gas generation unit 200 is the part that generates chlorine dioxide gas.

[0194] Furthermore, the gas generation unit 200 includes a water injection tank 201, a reaction acid tank 202, a chlorite tank 203, a reaction vessel 207, and a wastewater tank 208.

[0195] The gas generation unit 200 also includes a reaction tank water injection pump 204, a reaction acid supply pump 205, a chlorite supply pump 206, and a reaction tank drainage pump 209. In the gas generation unit 200, chlorine dioxide raw materials are supplied from each tank to the reaction tank 207, where chlorine dioxide is generated.

[0196] Furthermore, the inside of the reaction vessel 207 is aerated by the aeration pump 221, and the chlorine dioxide generated in the reaction vessel 207 is supplied to the inside of the safety cabinet B3 via the gas supply tube 222.

[0197] In this decontamination mechanism A2, as described above, the control unit observes the difference between the internal pressure of the safety cabinet and atmospheric pressure in real time, controls the operation of the internal pressure exhaust pump 103, and maintains the internal pressure of the safety cabinet at a negative pressure relative to atmospheric pressure.

[0198] As a result, in the decontamination mechanism A2, the internal pressure of the safety cabinet B3 increases when chlorine dioxide is supplied, becoming positive pressure relative to atmospheric pressure. This increase in internal pressure prevents chlorine dioxide from leaking to the outside through the front opening of the safety cabinet B3, which is sealed with tape or the like.

[0199] For example, if approximately 2.98 L of chlorine dioxide is supplied to the inside of a safety cabinet with an internal volume of approximately 576 L, the internal pressure will rise by approximately 5.3 hPa. If the pressure difference between the internal pressure of the safety cabinet and atmospheric pressure is approximately 5.3 hPa, then the area will rise by approximately 0.96 m². 2 A load of approximately 508.8N (equivalent to approximately 51.9kgf) will be applied to the front panel of the safety cabinet.

[0200] Therefore, in the decontamination mechanism A2, the control unit monitors the difference between the internal pressure of the safety cabinet B3 and atmospheric pressure in real time, and maintains the internal pressure as negative relative to atmospheric pressure. This suppresses the leakage of chlorine dioxide from the inside to the outside of the safety cabinet B3 and reduces the load on the internal structure of the safety cabinet B3 that would otherwise be caused by an increase in internal pressure.

[0201] Furthermore, in decontamination mechanism A2, similar to decontamination mechanism A described above, chlorine dioxide is thoroughly distributed inside the equipment being decontaminated during the decontamination process, resulting in an excellent decontamination effect.

[0202] Although the present invention has been specifically described above based on embodiments, it goes without saying that the present invention is not limited to the above embodiments and can be modified in various ways without departing from its essence. [Examples]

[0203] The following examples will be described.

[0204] [Decontamination and BI-based assessment] Decontamination was performed using decontamination mechanism A, to which the present invention is applied, and decontamination was performed without using decontamination mechanism A. The effectiveness of the decontamination was then determined using BI (Biological Indicator) devices installed at multiple locations inside the safety cabinet. Example 1 is a decontamination performed using decontamination mechanism A. Example 2 is a decontamination performed on a different day from Example 1, under the same conditions as Example 1. Comparative Example 1 is a configuration of decontamination mechanism A in which the decontamination gas is supplied from the supply tube 21 to the introduction space I without a gas dispersion unit 3, and the exhaust port B1 is directly connected to the gas circulation path 7 without a dispersion suction unit 4. Comparative Example 2 is a decontamination performed on a different day from Comparative Example 1, under the same conditions as Comparative Example 1. Comparative Example 3 is a decontamination performed on a different day from Comparative Examples 1 and 2, under the same conditions as Comparative Example 1. Comparative Example 4 is a decontamination performed on a different day from Comparative Examples 1, 2, and 3, under the same conditions as Comparative Example 1. Comparative Example 5 is a second decontamination performed on the same day as Comparative Example 4, under the same conditions as Comparative Example 1. Furthermore, in Examples 1 and 2, and Comparative Examples 1 to 5, decontamination was performed on the same safety cabinet used in normal operation.

[0205] The decontamination conditions for Examples 1 and 2, and Comparative Examples 1 to 5 are as follows. Decontamination gas: Chlorine dioxide Fumigation time (exposure process time): 200 minutes Target CT value: 2,000 Target concentration: 600ppm Figure 5 shows a graph illustrating the changes in chlorine dioxide concentration and CT value over time in the workspace S for the decontamination in Example 1.

[0206] Furthermore, for the biomarker (BI) test, BI was placed in the following nine locations within the safety cabinet to perform decontamination. After decontamination, the BI was collected and cultured in a culture medium for 48 hours to confirm whether the indicator bacterium, B. atrophaeus, originally contained in the BI, had been sterilized. In addition, BI not placed inside the safety cabinet was used as a positive control. (Location of BI installation) 1. Left side position of the secondary side of the exhaust HEPA filter 11 2. Central position of the secondary side of the exhaust HEPA filter 11 3. Right side position of the secondary side of the exhaust HEPA filter 11 4. Left side position of positive pressure plenum 15 5. Right-side position of positive pressure plenum 15 6. Left side position of the primary side of the supply air HEPA filter 12 7. Right side position of the primary side of the supply air HEPA filter 12 8. Left side position of introduction space I 9. Right-side position of introduction space I 10. Positive control (not installed inside a safety cabinet) Furthermore, "the secondary side of the filter" refers to the part where the air has passed through the filter, while "the primary side of the filter" refers to the part where the air has not yet passed through the filter.

[0207] In Examples 1 and 2, no proliferation of B. atrophaeus retained in BI was observed at all BI installation locations 1-9, even after 48 hours of incubation. Proliferation was observed only in the positive control, confirming the effectiveness of decontamination at all installation locations 1-9.

[0208] On the other hand, in Comparative Example 1, when the decontaminated BI was cultured for 48 hours at "4. Left position of positive pressure plenum 15" and "9. Right position of introduction space I", the proliferation of B. atrophaeus retained in the BI was confirmed.

[0209] Furthermore, in Comparative Example 2, when the decontaminated BI was cultured for 48 hours at "2. Central position on the secondary side of the exhaust HEPA filter 11", "6. Left position on the primary side of the supply air HEPA filter 12", "8. Left position in the introduction space I", and "9. Right position in the introduction space I", the proliferation of B. atrophaeus retained in the BI was confirmed.

[0210] Furthermore, in Comparative Example 3, when the decontaminated BI was cultured for 48 hours at "1. Left position on the secondary side of the exhaust HEPA filter 11", "2. Central position on the secondary side of the exhaust HEPA filter 11", "8. Left position on the introduction space I", and "9. Right position on the introduction space I", the proliferation of B. atrophaeus retained in the BI was confirmed.

[0211] Furthermore, in Comparative Example 4, when the decontaminated BI was cultured for 48 hours at "1. Left position on the secondary side of the exhaust HEPA filter 11", "7. Right position on the primary side of the supply air HEPA filter 12", and "9. Right position in the introduction space I", the proliferation of B. atrophaeus retained in the BI was confirmed.

[0212] Furthermore, in Comparative Example 5, when the decontaminated BI was cultured for 48 hours at "1. Left side of the secondary side of the exhaust HEPA filter 11", "2. Central side of the secondary side of the exhaust HEPA filter 11", "3. Right side of the secondary side of the exhaust HEPA filter 11", "5. Right side of the positive pressure plenum 15", "8. Left side of the introduction space I", and "9. Right side of the introduction space I", the proliferation of B. atrophaeus retained in the BI was confirmed.

[0213] [Comparison of metal corrosion under different humidity levels during decontamination] To confirm the effect of differences in humidity environments within the equipment space on metal corrosion when decontaminating the equipment using a decontamination mechanism, the following tests were conducted. In this test, six types of metal test specimens—aluminum, stainless steel, brass, lead, copper, and iron—were prepared. Each was placed in an exposure test box to simulate a decontaminated object, and treated under different conditions such as humidity, as described in the following examples and comparative examples. Details of the metal test specimens are as follows. AS ONE Corporation, Aluminum Metal Plate, 50 x 100 x 0.5 (mm), Model Number: AZ551 AS ONE Corporation Stainless Steel (SUS430) Metal Plate, 50 x 100 x 0.5 (mm), Model Number: SZ554 AS ONE Corporation metal plate, brass, 50 x 100 x 1.0 (mm), Model number: YZ152 AS ONE Corporation metal plate, lead, 50 x 300 x 0.5 (mm), Model number: GZ555 AS ONE Corporation Co., Ltd. Metal Plate, Copper, 50 x 100 x 0.5 (mm), Model Number: CZ553 Nippon Steel Corporation-made metal plate (iron). Product name: COLD ROLLED STEEL SHEET

[0214] Comparative Example 6: Exposure test box in a high humidity environment (relative humidity: 94.9%, maximum absolute humidity: 19.5 g / m³) 3 ) Decontamination was carried out, but the decontamination gas was not recovered. Comparative Example 7: Exposure test box in a high humidity environment (relative humidity: 90.4%, maximum absolute humidity: 18.5 g / m³) 3 Decontamination was carried out and decontamination gases were recovered. Regarding lead and iron, a high-humidity environment (relative humidity: 84%, maximum absolute humidity: 16 g / m³) was used. 3 I went there. Example 3: Before decontamination, the exposure test box was dehumidified to create a low-humidity environment (relative humidity: 49%, maximum absolute humidity: 8.6 g / m³). 3 The area was then decontaminated, and the decontamination gases were recovered. Regarding lead and iron, a low-humidity environment (relative humidity: 48%, maximum absolute humidity: 9.3 g / m³) was used. 3 I went there. Comparative Example 8: No decontamination was performed inside the exposure test box (non-exposure). In Example 3 and Comparative Examples 6 and 7, chlorine dioxide gas was used as the decontamination gas, and decontamination was performed under the same conditions to achieve a target CT value of 1,100.

[0215] [Quantification of residual chlorine content] Metal corrosion is assumed to occur when chlorine from the decontamination gas chlorine dioxide adheres to the metal surface, reacts with oxygen in the air, and forms rust on the metal surface. Therefore, the residual chlorine content of metal test pieces that underwent Example 3 and Comparative Examples 6-8 was quantified using an energy-dispersive micro-area X-ray fluorescence analyzer M4 (manufactured by Bruker AXS, Germany). In Comparative Example 6 only, the test was conducted on copper, brass, aluminum, and stainless steel. When metal test pieces are evaluated using the energy-dispersive micro-area X-ray fluorescence analyzer M4, spectra derived from six elements—zinc (Zn), aluminum (Al), chlorine (Cl), chromium (Cr), iron (Fe), and copper (Cu)—are obtained. The percentage of chlorine (Cl) content detected in each metal test piece, with the total amount of these six elements set to 100%, was defined as the residual chlorine content (%). Figures 10 to 15 show the results for Comparative Example 6, Comparative Example 7, Example 3, and Comparative Example 8 from left to right. The numerical values ​​listed under "Map Measurement Low Tonic Value Cl" at the bottom of each figure represent the residual chlorine amount (%).

[0216] As shown in Figure 10, in the aluminum test specimen, the residual chlorine content in Example 3 was a low value of 0.01%.

[0217] As shown in Figure 11, in Example 3, the residual chlorine content in the stainless steel test piece was 0.00%, meaning it was not detected.

[0218] As shown in Figure 12, in the brass test piece, the residual chlorine content in Example 3 was a low value of 0.02%.

[0219] As shown in Figure 13, in the lead test specimen, the residual chlorine content in Example 3 was 0.00%, meaning it was not detected.

[0220] As shown in Figure 14, in Example 3, the residual chlorine content in the copper test specimen was a low value of 0.01%.

[0221] As shown in Figure 15, in the iron test piece, the residual chlorine content in Example 3 was a low value of 0.05%.

[0222] [Observation of the degree of metal corrosion] The degree of corrosion on the metal surface of the metal test specimens from Example 3 and Comparative Examples 6-8 was observed using a polarizing microscope (Leica Microsystems) and polarizing reflection polarization (differential interference diffraction) spectroscopy. Only Comparative Example 6 was tested on copper, brass, aluminum, and stainless steel. Figures 16 and 17 show the results for Comparative Example 6, Comparative Example 7, Example 3, and Comparative Example 8, from left to right. Figure 16 shows the results for copper, brass, aluminum, and stainless steel, while Figure 17 shows the results for lead and iron.

[0223] As shown in Figure 16, the surfaces of the copper, brass, aluminum, and stainless steel metal test pieces in Example 3 did not show any bubble-like patterns originating from metal corrosion, and the surfaces were similar to those of Comparative Example 8, which was not decontaminated. On the other hand, in Comparative Examples 6 and 7, multiple bubble-like patterns originating from metal corrosion were observed on the surfaces of the copper, brass, aluminum, and stainless steel metal test pieces.

[0224] As shown in Figure 17, the surfaces of the lead and iron metal test pieces in Example 3 did not show any bubble-like patterns originating from metal corrosion, and the surfaces were similar to those of Comparative Example 8, which was not decontaminated. On the other hand, in Comparative Example 7, multiple bubble-like patterns originating from metal corrosion were observed on the surfaces of the lead and iron metal test pieces. [Explanation of Symbols]

[0225] A Decontamination Mechanism B Safety Cabinet 10 Main Unit 11. Exhaust HEPA filter 12. Intake air HEPA filter 13 Workbench 14 Front Panel 15. Positive pressure plenum 16 Blower 17. Vacuum Plenum S workspace I. Introduction Space B1 outlet 2. Gas supply section 20 Gas generation section 21 Supply tube 22 Recovery tubes 3. Gas dispersion section 30 Connection part 31 Hole 32 Hole 3a Gas dispersion section 31a Hole 32a hole 3b Gas dispersion section 33 Hole 4 Dispersion suction section 40 Occlusion plate 400 Ventilation section 40a Occlusion plate 400a ventilation section 41 Lid 410 Opening 5. Recovery device 50 Upper management 500 Diverter Valve 51 Middle section 510 Diverter Valve 52 Lower part 520 Diverter Valve 6. Air pump 7. Gas circulation pathway 8a Pressure flow meter 8b Pressure flow meter 9a Needle valve 9b Needle valve B2 supply port S10 (Space covered by the lid) A2 Decontamination mechanism B3 Safety Cabinet 100 Cabinet internal pressure sensor 101 Gas discharge pathway 102 Atmospheric pressure sensor 103 Internal pressure exhaust pump 104 Internal pressure exhaust filter 110 Internal air return tube 110 111 Chlorine dioxide gas measurement section 112 Measuring Unit Supply Pump 113 Flow control valve 114 Optical path pressure sensor 115 Chlorine dioxide gas measurement optical path 200 Gas generation unit 201 Water Injection Tank 202 Reaction Acid Tank 203 Chlorite Tank 204 Reaction tank water injection pump 205 Reaction Acid Supply Pump 206 Chlorite supply pump 207 Reaction vessel 208 Drainage Tank 209 Reaction tank drainage pump 220 Internal air collection tube 221 Aeration pump 222 Gas supply tube 7A Gas circulation path 70 Circulating blower 71 Circulation pressure release valve 72 Dehumidifying Filter 73 Recovery filter 74 Filter activation / deactivation valve 75 Dehumidifying filter switching valve 76 Recovery filter switching valve

Claims

1. A decontamination mechanism for a predetermined device having a main body with a working space formed inside, and an exhaust filter that sterilizes the air in the working space before exhausting it to the outside of the main body from an exhaust section, A decontamination gas supply path supplies decontamination gas from outside the main body towards an introduction space formed inside the main body and communicating with the work space, A cylindrical body placed in the introduction space and connected to the decontamination gas supply path, comprising a gas dispersion section with multiple holes formed on its outer surface, A plate-like body that blocks the exhaust section, and a blocking plate having multiple ventilation holes formed through the plate-like body, An umbrella-shaped body that covers the region in which multiple ventilation portions are formed on the aforementioned closure plate, the end of which is connected to the edge of the closure plate, and the lid portion having an opening formed at its top, A gas circulation path connects the aforementioned opening to a supply port formed in the main body and communicating with the working space, forming a gas flow path, An air pump provided on the gas circulation path circulates gas between the inside of the main body and the gas circulation path, A dehumidifying unit is provided on the gas circulation path and dehumidifies the air in the work space before or after the decontamination is performed, The system includes a recovery unit provided on the gas circulation path for recovering the decontamination gas from the air in the work space that has been exposed to the decontamination gas for a certain period of time. Decontamination mechanism.

2. The gas dispersion section has a closed path formed in a plan view, and when the entire range of the closed path is divided into a region close to the connection point connected to the decontamination gas supply path and a region far from the connection point, the number of holes in the far region is greater than the number of holes in the close region. The decontamination mechanism according to claim 1.

3. The gas dispersion section is formed such that the size of the holes in the distant region is larger than the size of the holes in the nearby region. The decontamination mechanism according to claim 2.

4. The aforementioned closure plate is a corrosion-resistant porous plate, and the ratio of the total area of ​​the multiple ventilation parts to the area of ​​the plate-like body is 3% or more and 8% or less. A decontamination mechanism according to claim 1 or claim 2.

5. The recovery device comprises a dehumidifying layer on which the dehumidifying section is provided, a recovery layer on which the recovery section is provided, and a gas circulation path having a flow path that passes through the dehumidifying layer and a switching section that can switch between the flow path that passes through the recovery layer. A decontamination mechanism according to claim 1 or claim 2.

6. The aforementioned air pump can variably control the flow rate of the gas. A first measuring unit is provided between the opening and the air pump on the gas circulation path for measuring the gas flow rate and pressure. A first adjustment unit is provided between the opening and the air pump on the gas circulation path, for adjusting the flow rate and pressure of the gas. A second measuring unit is provided between the air pump and the supply port on the gas circulation path for measuring the gas flow rate and pressure. The gas circulation path is provided between the air pump and the supply port, and includes a second adjustment unit for adjusting the gas flow rate and pressure. Based on the measurement values ​​from the first and second measuring units, the air pump, the first adjustment unit, and the second adjustment unit are controlled to maintain a uniform pressure within the workspace. A decontamination mechanism according to claim 1 or claim 2.

7. The air pump controls the gas flow rate based on the differential pressure, which is the difference between the pressure of the gas flowing between the opening in the gas circulation path and the air pump, and the pressure of the gas flowing between the air pump and the supply port in the gas circulation path. A decontamination mechanism according to claim 1 or claim 2.

8. The dehumidifying section contains crystalline zeolite capable of adsorbing substances with a molecular diameter of less than 0.3 nm. A decontamination mechanism according to claim 1 or claim 2.

9. The aforementioned specified device is a safety cabinet or an isolator for animal rearing. A decontamination mechanism according to claim 1 or claim 2.

10. Based on the measurement results of the internal-external pressure difference, which is the difference between the gas pressure inside the main body and the gas pressure outside the main body, the main body is equipped with a gas discharge section that discharges the gas inside the main body to the outside via a gas discharge path. A decontamination mechanism according to claim 1 or claim 2.

11. The gas discharge path is provided with an exhaust recovery unit that recovers the decontamination gas from the discharged gas. The decontamination mechanism according to claim 10.

12. The gas discharge unit discharges gas in such a way that it maintains the internal gas pressure of the main body at a positive pressure of 1 hPa or less, relative to the external gas pressure of the main body. The decontamination mechanism according to claim 10.

13. The gas discharge unit discharges gas in such a way that it maintains a negative pressure for the gas inside the main body relative to the gas pressure outside the main body. The decontamination mechanism according to claim 10.

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