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] The present invention relates to a decontamination mechanism. More specifically, it relates to a decontamination mechanism in which decontamination gas can be sufficiently distributed inside the device to be decontaminated during decontamination, and an excellent decontamination effect can be obtained.

Background Art

[0002] For decontamination inside devices such as infection prevention of inspectors during regular inspections of safety cabinets and working spaces such as isolators for animal experiments, decontamination using decontamination gas is performed.

[0003] In addition, as the gas used for decontamination (decontamination gas), formaldehyde, chlorine dioxide, peracetic acid, and hydrogen peroxide are common.

[0004] Here, for example, in the decontamination of a safety cabinet with formaldehyde, the cabinet exhaust port and the front opening are closed with a plastic film, duct tape, etc. to prevent the decontamination gas from leaking outside the device.

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

[0006] Furthermore, when it is insufficient to only install a blower inside the cabinet, it is recommended to additionally install a blower outside the cabinet to form a circulation path for circulating the decontamination gas on the downstream side (secondary side) of the exhaust filter under the workbench (see, for example, Non-Patent Document 1).

Prior Art Documents

Non-Patent Documents

[0007]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0008] However, in the actual decontamination work, since formaldehyde is a carcinogenic substance, fearing that decontamination gas may leak during decontamination, instead of installing blowers inside and outside the cabinet, only the exhaust ports and the like are closed with plastic films or the like, and this is the actual situation where decontamination is carried out.

[0009] Therefore, inside the safety cabinet, in the parts where it is difficult for the decontamination gas to reach, the decontamination gas did not reach at all, and the decontamination effect was insufficient. Also, regarding decontamination gases other than formaldehyde, considering the risk during leakage, the same actual situation exists.

[0010] Also, even if blowers are installed inside and outside the cabinet to form a circulation path for the decontamination gas, just by the blowing of the blowers, the decontamination gas could not reach every corner inside the safety cabinet sufficiently.

[0011] The present invention was devised in view of the above points, and aims to provide a decontamination mechanism in which the decontamination gas spreads sufficiently inside the device to be decontaminated during decontamination, and an excellent decontamination effect can be obtained.

Means for Solving the Problems

[0012] To achieve the above object, the decontamination mechanism of the present invention is a decontamination mechanism for performing decontamination on a predetermined device having a main body with a working space formed therein and an exhaust filter for sterilizing the air in the working space before exhausting it from an exhaust portion to the outside of the main body. The decontamination mechanism includes a decontamination gas supply path for supplying decontamination gas supplied from the outside of the main body toward an introduction space that is a space formed inside the main body and communicates with the working space, a gas dispersion portion that is a cylindrical body disposed in the introduction space and connected to the decontamination gas supply path and has a plurality of hole portions formed on its outer peripheral surface, a closing plate that is a plate-like body for closing the exhaust portion and has a plurality of ventilation portions formed therethrough, an umbrella-shaped body that covers a region where the plurality of ventilation portions of the closing plate are formed, an end portion of which is connected to an edge portion of the closing plate and an opening portion is formed at the top, a gas circulation path that connects the opening portion and a supply port formed in the main body and communicating with the working space to form 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 dehumidifying portion provided on the gas circulation path for dehumidifying the air in the working space before or after performing the decontamination, and a recovery portion provided on the gas circulation path for recovering the decontamination gas from the air in the working space that has been exposed to the decontamination gas for a certain period of time.

[0013] Here, by the decontamination gas supply path supplying the decontamination gas supplied from the outside of the main body toward the introduction space that is a space formed inside the main body and communicates with the working space, it becomes possible to supply the decontamination gas generated outside the predetermined device into the inside of the main body of the predetermined device and to reach the working space with the decontamination gas.

[0014] Also, since the gas dispersion portion is a cylindrical body disposed in the introduction space and connected to the decontamination gas supply path and has a plurality of hole portions formed on its outer peripheral surface, the decontamination gas supplied from the decontamination gas supply path can be dispersed into the introduction space through the plurality of hole portions. That is, since it becomes possible to supply the decontamination gas to a plurality of positions in the introduction space, it is easy to evenly distribute the decontamination gas to every corner of the introduction space.

[0015] Further, it is a plate-like body that closes the exhaust part, and a closing plate in which a plurality of ventilation parts penetrating the plate-like body are formed, and an umbrella-like body that covers the area where the plurality of ventilation parts of the closing plate are formed, and its end is connected to the edge of the closing plate, and at the top A lid portion having an opening formed thereon allows air to flow through the plurality of ventilation portions, so that the flow of air flowing from the space between the exhaust filter and the exhaust portion 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 portion, the flow of air can be dispersed, and the decontaminated gas can be evenly distributed to every corner of the space.

[0016] In addition, since an opening is formed at the top of the lid portion, it becomes possible to discharge air to the outside of the exhaust portion through the opening.

[0017] Further, an opening is formed at the top of the lid portion, and the gas circulation path connects the opening and a supply port formed in the main body and communicating with the working space, and forms a gas flow path, so that outside the main body, an exhaust portion and a supply port can be formed. A gas flow path connecting them can be constructed.

[0018] In addition, 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, the supply port, the working space, the exhaust filter, and the exhaust portion inside the main body and the gas circulation path are formed. Along the gas flow path, the decontaminated gas can be circulated.

[0019] In addition, a dehumidifying portion 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 brought into a low humidity environment where the contents are less likely to corrode. 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 an environment with high humidity, by lowering the humidity inside the working space before or after decontamination and proceeding with the treatment, corrosion of the contents can be suppressed.

[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 the entire range of the closed path is divided into a region close to the connection part and a region far from the connection part with the connection part connected to the decontamination gas supply path as a reference, 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 there is no break in the middle of the path except for the hole parts 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, when the blocking plate is a corrosion-resistant perforated plate and the ratio of the total area of the plurality of ventilation parts to the area of the plate-like body is less than 3%, the air flow in the ventilation parts deteriorates, which may hinder the circulation of the decontaminated gas and reduce the decontamination efficiency. On the other hand, when the blocking plate is a corrosion-resistant perforated plate and the ratio of the total area of the plurality of ventilation parts to the area of the plate-like body exceeds 8%, the air flow passing through the blocking plate is likely to be uneven, making it difficult to evenly distribute the decontaminated gas to every corner of the space between the exhaust filter and the exhaust part.

[0025] In addition, when a recovery device is provided with a dehumidifying part layer provided with a dehumidifying part, a recovery part layer provided with a recovery part, and a switching part capable of switching a flow path passing through the dehumidifying part layer and a flow path passing through the recovery part layer on the gas circulation path, both dehumidification before decontamination and recovery of the decontaminated gas after decontamination can be performed with one recovery device provided in the gas circulation path, and the device can be miniaturized.

[0026] In addition, when the air pump can variably control the gas flow rate, and there are a first measurement part provided between the opening and the air pump on the gas circulation path for measuring the gas flow rate and pressure, a first adjustment part provided between the opening and the air pump on the gas circulation path for adjusting the gas flow rate and pressure, a second measurement part provided between the air pump and the supply port on the gas circulation path for measuring the gas flow rate and pressure, and a second adjustment part provided between the air pump and the supply port on the gas circulation path for adjusting the gas flow rate and pressure, and the air pump, the first adjustment part, and the second adjustment part are controlled based on the measurement values of the first measurement part and the second measurement part to uniformly maintain the pressure in the working space, the air pump can control the gas flow rate to efficiently circulate the decontaminated gas. Also, it becomes easier to keep the air pressure in the working space at a negative pressure, and leakage of the decontaminated gas caused by the space becoming a positive pressure can be suppressed.

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

[0028] In addition, when the dehumidifying section contains crystalline zeolite capable of adsorbing substances with a molecular diameter of less than 0.3 nm, water molecules contained in the air in the working space can be adsorbed by the crystalline zeolite to perform sufficient dehumidification.

[0029] In addition, when the predetermined device is a safety cabinet or an isolator for animal breeding, sufficient decontamination gas can be spread to each part inside the safety cabinet or the isolator for animal breeding to perform sufficient decontamination.

[0030] In addition, based on the measurement result of the internal and external differential pressure, which is the difference between the pressure of the gas inside the main body and the pressure of the gas outside the main body, when a gas discharge section is provided to discharge the gas inside the main body to the outside through a gas discharge path, leakage of the decontamination gas from the inside of the main body to the outside caused by the increase in the internal pressure of the main body with respect to the external air pressure of the main body of the predetermined device can be suppressed. Thereby, the exposure amount of the decontamination gas to the indoor space where the predetermined device is installed and the workers performing decontamination can be reduced.

[0031] In addition, when an exhaust gas recovery section is provided on the gas discharge path to recover the decontamination gas from the discharged gas, the concentration of the decontamination gas in the gas discharged from the inside of the main body can be reduced to a concentration safe for the human body etc. before being discharged to the outside. That is, the indoor space where the predetermined device is installed can be made into a safe environment that can be used by workers etc.

[0032] Also, when the gas discharge unit discharges gas so as to maintain the pressure of the gas inside the main body at 1 hPa or less under positive pressure with respect to the pressure of the gas outside the main body, leakage of the decontamination gas from the inside of the main body to the outside, which is caused by the increase in the internal air pressure of the main body, can be sufficiently suppressed.

[0033] Also, when the gas discharge unit discharges gas so as to maintain the pressure of the gas inside the main body at a negative pressure with respect to the pressure of the gas outside the main body, leakage of the decontamination gas from the inside of the main body to the outside, which is caused by the increase in the internal air pressure of the main body, can be more sufficiently suppressed.

Advantages of the Invention

[0034] The decontamination mechanism according to the present invention allows the decontamination gas to sufficiently spread inside the device to be decontaminated during decontamination, and an excellent decontamination effect can be obtained.

Brief Description of the Drawings

[0035]

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Mode for Carrying Out the Invention

[0036] [First Embodiment of the Present Invention] Hereinafter, the first embodiment of the present invention will be described with reference to the drawings for the purpose of understanding the present invention. Note that the content shown below is merely an example of the structure to which the present invention is applied, and the embodiments of the present invention are not limited to the structure shown below.

[0037] In the following description, based on FIG. 1, the upper side of the paper surface is referred to as "upper" or "above", and the lower side of the paper surface is referred to as "lower" or "below". Also, based on FIG. 1, the front side of the paper surface is referred to as "front" or "forward", and the back side of the paper surface is referred to as "back" or "rear".

[0038] As shown in Fig. 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. Here, the working space S corresponds to the working space in the claims of the present application. Also, the safety cabinet B here corresponds to the predetermined device in the claims of the present application.

[0039] In addition, the safety cabinet B is a device that confines biological disasters (biohazards) such as pathogens and genetically modified organisms and realizes a safe working environment. For example, it is installed in laboratories of universities, research institutions, medical institutions, etc. Also, the safety cabinet B shown here is classified as Class IIA2.

[0040] First, with reference to Figs. 8(a) and 8(b), the main structure of the safety cabinet B to be decontaminated will be described.

[0041] The safety cabinet B has a main body 10, an exhaust HEPA (High-Efficiency Particulate Air filter) filter 11, a supply HEPA filter 12, a workbench 13, and a front panel 14 (see Fig. 8(a)). Also, a working space S is formed inside the main body 10, and the workbench 13 constitutes the bottom surface of the working space S.

[0042] In addition, the safety cabinet B has an introduction space I, which is a space that communicates with the working space S airtightly, below the workbench 13 (see Figs. 8(a) and 8(b)).

[0043] Also, the positive pressure plenum 15 is a space covered by the exhaust HEPA filter 11 and the supply HEPA filter 12 (see Figs. 8(a) and 8(b)). Also, a blower 16 is provided adjacent to the positive pressure plenum 15. Also, the space marked with reference numeral 17 in Fig. 1 is a negative pressure plenum, and the introduction space I corresponds to a part of the negative pressure plenum 17. More specifically, the region marked with a dotted pattern in Fig. 9 corresponds to the negative pressure plenum 17.

[0044] During normal use without decontamination, this safety cabinet B uses a fan to draw aerosol generated in the working space S through the negative pressure plenum 17. Part of it is purified through the supply HEPA filter 12 and circulated back into the working space S, while part of it is purified through the exhaust HEPA filter 11 and discharged into the environment (see Figures 8(a) and 8(b)).

[0045] Also, during normal use, in the safety cabinet B, the air sent from the blower 16 passes through the positive pressure plenum 15, is purified through the supply HEPA filter 12, and is supplied to the working space S. This keeps the inside of the working space S clean.

[0046] In addition, in the safety cabinet B, by balancing the inflow air velocity w1 and the blowing air velocity w2 of the clean air, the movement of contaminated aerosol in and out of the cabinet is prevented (see Figure 8(a)). Also, the working space S is designed to be approximately 3 ~5m 3 in size.

[0047] Note that the safety cabinet to be decontaminated in the decontamination mechanism of the present invention is not limited to the structure of the safety cabinet B described above, and can be applied to various known safety cabinets classified as Class II. Also, in the decontamination mechanism of the present invention, not only safety cabinets but also isolators for animal breeding can be targeted for decontamination.

[0048] Moreover, for the filters 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 fine particles.

[0049] Next, the decontamination mechanism A will be described. In the decontamination mechanism A shown in Fig. 1, in addition to the safety cabinet B having the above-described structure, it includes 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] Further, the decontamination mechanism A includes a gas circulation path 7, and on the path of this gas circulation path 7, 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 are provided. Also, in Fig. 1, the decontamination gas is schematically shown by a cloud-shaped figure.

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

[0052] Also, the gas dispersion unit 3 is a member that disperses the decontamination gas supplied from the decontamination gas supply unit 2 within the space of the introduction space I of the safety cabinet B and spreads the decontamination gas inside the main body 10.

[0053] Also, the dispersion suction unit 4 is a member that spreads the decontamination gas flowing toward the exhaust HEPA filter 11 through the work space S and other parts inside the main body 10 to every corner of the space connected to the exhaust HEPA filter 11 and the exhaust port B1 ahead thereof, and discharges it to the gas circulation path 7.

[0054] Also, the recovery device 5 is a device that dehumidifies the air in the work space S before starting decontamination or after performing decontamination. Also, the recovery device 5 is a device for recovering the decontamination gas contained in the air in the work space S after the end of decontamination and reducing the concentration of the decontamination gas to a safe concentration.

[0055] Also, the air pump 6 is a member for generating a gas flow that circulates air between the inside of the main body 10 of the safety cabinet B and the gas circulation path 7.

[0056] Further, the gas circulation path 7 is a portion that is in air communication with the inside of the main body 10 of the safety cabinet B and serves as a gas flow path outside the safety cabinet B.

[0057] Further, the pressure flow meter 8a is a member 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. Further, the needle valve 9a is a member for adjusting 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] Further, the pressure flow meter 8b is a member that measures the pressure and flow rate of the gas flowing between the air pump 6 and the supply port B2 (see FIG. 1) formed in the main body 10 and communicating with the working space S in the gas circulation path 7. Further, the needle valve 9b is a member for adjusting the flow rate of the gas flowing between the air pump 6 and the supply port B2 in the gas circulation path 7.

[0059] Subsequently, the detailed structure of each part will be described.

[0060] [Decontamination gas supply unit] First, the decontamination gas supply unit 2 includes a gas generation unit 20, a supply tube 21, and a recovery tube 22 (see FIG. 1).

[0061] Although not shown, the gas generation unit 20 is composed of an aeration tank, a pump, a chemical solution tank, a waste liquid tank, etc., and is a part that generates decontamination gas. Further, as the decontamination gas, gases that can be used for decontamination, such as formaldehyde, chlorine dioxide, peracetic acid, and hydrogen peroxide, can be appropriately selected. Further, the gas generation unit 20 can be appropriately designed according to the type of decontamination gas to be used.

[0062] Further, the supply tube 21 is a tube member that serves as a gas flow path for supplying the decontamination gas generated by the gas generation unit 20 to the gas dispersion unit 3 during the rising process of reaching the target concentration of the decontamination gas concentration inside the working space S.

[0063] In addition, the recovery tube 22 is a tube member that serves as a gas flow path for recovering gas from the dispersion suction unit 4 toward the gas generation unit 20 during the rising process. The gas that has passed through the recovery tube 22 is used for generating decontamination gas in the gas generation unit 20.

[0064] [Gas dispersion unit] As shown in Fig. 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. Also, in the gas dispersion unit 3, the connection part 30 is located in the front.

[0065] That is, in the safety cabinet B, the region of the gas dispersion unit 3 where the connection part 30 is located is on the front side, and the region on the opposite side is on the rear side. Here, the connection part 30 corresponds to the connection part in the claims of the present application.

[0066] In addition, in the gas dispersion unit 3, a plurality of hole parts 31 are formed in the region close to the connection part 30 with the connection part 30 as a reference, and a plurality of hole parts 32 are formed in the region far from the connection part 30.

[0067] Also, in the gas dispersion unit 3, the number of the hole parts 32 is formed to be larger than the number of the hole parts 31. Also, the size of the holes of the hole parts 32 is formed to be larger than the size of the holes of the hole parts 31.

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

[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 from the plurality of hole parts 31 or the hole parts 32 toward the introduction space I. In the gas dispersion unit 3, in order to discharge the decontamination gas from the plurality of hole parts 31 or the hole parts 32, the gas can be uniformly dispersed in the space of the introduction space I.

[0070] In addition, in the gas dispersion section 3, the number of a plurality of holes 32 provided in a region far from the connection section 30 is larger than that of a plurality of holes 31 formed in a region close to the connection section 30, and the size of the holes is also larger. Therefore, even at a position behind the introduction space I, it is easier to discharge the decontaminated gas from the dispersion section 3. As a result, the decontaminated gas can be spread to every corner of the introduction space I.

[0071] Also, the shape of the gas dispersion section 3 is not limited to the content shown in Fig. 2(a). For example, the gas dispersion section 3a shown in Fig. 2(b) constitutes an annular closed path in a plan view. Further, in the gas dispersion section 3a, a plurality of holes 31a are formed in a region close to the connection section 30a with reference to the connection section 30a, and a plurality of holes 32a are formed in a region far from the connection section 30.

[0072] Also, the number of the holes 32a is formed to be larger than that of the holes 31a, and the size of the holes of the holes 32a is formed to be larger than that of the holes of the holes 31a. In this way, a gas dispersion section 3a that is annular in a plan view can also be formed.

[0073] Furthermore, for example, the gas dispersion section 3b shown in Fig. 2(c) constitutes a linear path, and a plurality of holes 33 are formed. Also, with reference to the connection section 30b, more holes 33 are formed in a region outside the central side. In this way, a gas dispersion section 3b that is linear in a plan view can also be formed.

[0074] Here, although an example of the shape of the gas dispersion section 3 is shown in Figs. 2(a) to 2(c), from the viewpoint of uniformly dispersing the decontaminated gas in the introduction space I, the shape of the annular gas dispersion section 3a (Fig. 2(b)) is more preferable than that of the linear gas dispersion section 3b (Fig. 2(c)), and the shape of the rectangular gas dispersion section 3 (Fig. 2(a)) is even more preferable.

[0075] Also, it is not necessarily the case that in the gas dispersion unit 3, the number of the hole portions 32 is formed to be larger than the number of the hole portions 31, and the size of the holes of the hole portions 32 does not necessarily have to be formed to be larger than the size of the holes of the hole portions 31. However, as described above, from the viewpoint that it is easy to discharge the decontaminated gas from the dispersion unit 3 even at a position behind the introduction space I and the decontaminated gas can be spread to every corner of the introduction space I, it is preferable that in the gas dispersion unit 3, the number of the hole portions 32 is formed to be larger than the number of the hole portions 31, and the size of the holes of the hole portions 32 is formed to be larger than the size of the holes of the hole portions 31.

[0076] Also, although not shown, an air circulator is installed inside the work space S. This air circulator is a member that operates during the start-up process and the exposure process of decontamination to disperse the decontaminated gas in the space of the work space S.

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

[0078] Here, the closing plate 40 corresponds to the closing plate in the claims of the present application. Also, the lid part 41 here corresponds to the lid part in the claims of the present application.

[0079] This closing plate 40 is a plate-like body attached so as to close the exhaust port B1 of the safety cabinet B, and is formed of corrosion-resistant vinyl chloride. Further, a plurality of ventilation parts 400 penetrating the plate-like body are uniformly formed in the closing plate 40. Also, the ventilation parts 400 are circular hole parts.

[0080] Also, a pyramidal lid part 41 is provided above the closing plate 40. The outer edge of the lower end of the lid part 41 is continuously provided with the outer edge of the closing plate 40. Thereby, a space S10 covered with the lid part 41 is formed above the closing plate 40.

[0081] In addition, an opening 410 is formed at the top of the lid portion 41, and at this position of the opening 410, the lid portion 41 is connected to the gas circulation path 7. That is, the space S10 covered by the lid portion 41 is in air communication with the gas circulation path 7.

[0082] Note that the ventilation portion 400 mentioned here corresponds to the ventilation portion in the claims of the present application. Also, the opening 410 mentioned here corresponds to the opening in the claims of the present application.

[0083] In this dispersion suction portion 4, by allowing air to flow through the plurality of ventilation portions 400, the air flow from the space between the exhaust HEPA filter 11 and the exhaust port B1 to the space S10 surrounded by the lid portion 41 and the closing plate 40 can be dispersed.

[0084] Thereby, even in the space between the exhaust HEPA filter 11 and the exhaust port B1, the air flow can be dispersed, making it easier for the decontaminated gas to evenly spread to every corner of the space.

[0085] In particular, the space between the exhaust HEPA filter 11 and the exhaust port B1 is a space where the decontaminated gas does not spread and a positive result is likely to be obtained in the determination using BI, which is an index for decontamination, in the conventional decontamination method of simply installing a blower inside and outside the cabinet. Therefore, it is important to make the decontaminated gas spread to this part.

[0086] Also, the plurality of ventilation portions 400 formed in the closing plate 40 can be formed as slit-shaped ventilation portions 400a (see Fig. 3(b)). In the closing plate 40a shown in Fig. 3(b), a plurality of slits penetrating the plate-like body are uniformly formed.

[0087] In addition, in the plurality of ventilation parts 400 formed in the closing plate 40, it is preferable that the ratio of the total area of all the ventilation parts 400, that is, the area of the opened part, to the total area of the closing plate 40 is set to be 3% or more and 8% or less. By setting the ratio of the area of the opened part in this way, it becomes easier to disperse the air flow in the space between the exhaust HEPA filter 11 and the exhaust port B1, and it is possible to make the decontaminated gas evenly spread to every corner of the space.

[0088] On the other hand, when the ratio of the total area of the plurality of ventilation parts 400 to the total area of the closing plate 40 is less than 3%, the air flow in the ventilation parts 400 deteriorates, which may prevent the circulation of the decontaminated gas and reduce the decontamination efficiency. On the other hand, when the ratio of the total area of the plurality of ventilation parts 400 to the total area of the closing plate 40 exceeds 8%, the air flow passing through the closing plate 40 is likely to be biased, making it difficult to evenly spread the decontaminated gas to every corner of the space between the exhaust HEPA filter 11 and the exhaust port B1.

[0089] Also, it is not necessarily required that the closing plate 40 is formed of corrosion-resistant vinyl chloride. However, it is preferable to adopt a material having corrosion resistance.

[0090] [Recovery device] As shown in FIG. 4, inside the recovery device 5, there are formed three layers: an upper layer part 50 filled with crystalline zeolite, a middle layer part 51 filled with activated carbon, and a lower layer part 52 not filled with crystalline zeolite and activated carbon.

[0091] Note that the recovery device 5 mentioned here is a member corresponding to the recovery device in the claims of the present application. Also, the upper layer part 50 mentioned here corresponds to the dehumidifying part layer in the claims of the present application, and the middle layer part 51 mentioned here corresponds to the recovery part layer in the claims of the present application. Also, the crystalline zeolite mentioned here is a member corresponding to the crystalline zeolite in the claims of the present application.

[0092] In addition, the recovery device 5 is provided on the path of the gas circulation path 7, and the partially branched gas circulation path 7 is connected to three layers, namely, the upper layer portion 50, the middle layer portion 51, and the lower layer portion 52 of the recovery device 5 (see FIG. 4).

[0093] Also, on the gas circulation path 7, switching valves 500, 510, and 520 are respectively provided upstream and downstream of each layer, enabling the switching of the gas flow path. Here, the switching valves 500 and 510 correspond to the switching portions in the claims of the present application.

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

[0095] Here, the upper layer portion 50 filled with crystalline zeolite is a part for passing the air in the working space S before or after exposing the decontaminated gas to the working space S, adsorbing the water molecules contained in the air onto the crystalline zeolite after recovering the decontaminated gas in the middle layer portion 51, and dehumidifying the working space S.

[0096] Also, the middle layer portion 51 filled with activated carbon is a part for passing the air in the working space S after exposing the decontaminated gas to the working space S, adsorbing the decontaminated gas onto the activated carbon, and recovering it.

[0097] In addition, the lower layer portion 52 not filled with crystalline zeolite and activated carbon is a part that serves as the gas flow path of the gas circulation path 7 in the recovery device 5 during decontamination.

[0098] In this way, the recovery device 5 is a member that undertakes two processes: passing the air inside the working space S, dehumidifying before or after decontamination, and recovering the gas after exposing the decontaminated gas to the working space S.

[0099] In addition, the crystalline zeolite filled in the upper layer portion 50 is a crystalline zeolite capable of adsorbing substances with a molecular diameter of less than 0.3 nm, and is an aluminosilicate-based crystalline material. It has fine pores in the crystal and is configured to selectively adsorb water molecules. Also, this crystalline zeolite can adsorb 20% by weight of water molecules (water vapor).

[0100] Moreover, even after the adsorption capacity of the crystalline zeolite for water molecules is saturated, it can be regenerated by once recovering, washing, and drying it.

[0101] Here, the amount of the crystalline zeolite filled in the upper layer portion 50 can be set as appropriate. However, since the volume of the working space S is 1 m 3 ~5 m 3 and, before starting decontamination, the air in the working space S within this volume range is brought into an environment of low humidity with a relative humidity of less than 32% and an absolute humidity of less than 3.0 g / m 3 from the point of view of making it less than, the amount of the crystalline zeolite filled in the upper layer portion 50 is preferably 50 g to 2000 g, more preferably 100 to 1500 g, and even more preferably set to 200 g to 1000 g.

[0102] In addition, the activated carbon filled in the middle layer portion 51 is granular activated carbon composed of pellet-shaped activated carbon or amorphous crushed carbon, and the middle layer portion 51 is configured by filling granular activated carbon into a forming frame.

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

[0104] Also, in the middle layer portion 51, the amount of the activated carbon filled in the forming frame can be set as appropriate. However, since the volume of the working space S is 1 m 3 ~5 m 3That is, considering the need to efficiently expose the decontaminated gas to the gas within the volume range in a short period of time and the number of times of using activated carbon about one to three times, the amount of activated carbon filled in the middle layer portion 51 is preferably 50 g to 5000 g, more preferably 100 g to 2000 g, and even more preferably set to 200 g to 1200 g.

[0105] Also, it is not always necessary to adopt the recovery device 5 formed with the upper layer portion 50 filled with crystalline zeolite and the middle layer portion 51 filled with activated carbon. A mode may be adopted in which a member for performing dehumidification filled with crystalline zeolite and a member for recovering decontaminated gas filled with activated carbon are individually provided on the gas circulation path 7. However, by providing the upper layer portion 50 and the middle layer portion 51 and integrating them into one recovery device 5, during maintenance, it is only necessary to replace the recovery device 5, which facilitates the maintenance work. Therefore, it is preferable to use the recovery device 5 formed with the upper layer portion 50 filled with crystalline zeolite and the middle layer portion 51 filled with activated carbon.

[0106] [Air pump] As described above, the air pump 6 is a member for generating a gas flow that circulates 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 in each process of dehumidification before the start of decontamination (or dehumidification after decontamination and after recovery), the startup process before the exposure of the decontaminated gas, the exposure of the decontaminated gas, and the recovery after decontamination.

[0107] In addition, the air pump 6 has a fan motor capable of variably controlling the gas flow rate, and is a device for ensuring an optimal air volume in order to set the humidity and decontaminated gas concentration in the working space S to desired set values.

[0108] Also, the decontamination mechanism A has a control device (not shown). This control device controls the driving of the air pump 6, the needle valve 9a, and the needle valve 9b based on the measured values of the pressure flow meter 8a and the pressure flow meter 8b. Further, by controlling each member of this control device, the pressure in the working space S can be adjusted and maintained uniformly.

[0109] In addition, in the decontamination mechanism A, in order to prevent the decontamination gas from leaking to the outside of the safety cabinet B, a caulking film is attached to various exhaust ports, openings of devices, etc. (not shown).

[0110] Also, inside the work space S, a concentration measurement mechanism for measuring the relative humidity, absolute humidity, and concentration of the decontamination gas in the internal environment of the work space S is provided (not shown). Note that a known device can be adopted for the concentration measurement mechanism, and detailed description thereof is omitted in this content.

[0111] Here, it is not always necessary to provide the pressure flowmeter 8a and the pressure flowmeter 8b on the gas circulation path 7 and control the driving of the air pump 6, the needle valve 9a, and the needle valve 9b based on the respective measured values. For example, on the gas circulation path 7, the differential pressure between a position upstream of the air pump 6 and a position downstream of the air pump 6 is measured, and the air volume is controlled by the air pump 6 so that the differential pressure becomes zero, thereby adjusting and uniformly maintaining the pressure inside the work space S. According to this aspect, it is only necessary to measure the differential pressure upstream and downstream of the air pump 6, and there is no need to install a gas flowmeter or a needle valve.

[0112] Subsequently, an example of the flow of the decontamination operation using the decontamination mechanism A to which the present invention is applied will be described.

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

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

[0115] In this project, 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 part 50 of the recovery device 5.

[0116] When passing through this upper layer part 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, dehumidification is continuously performed until the relative humidity is less than 32% and the absolute humidity is less than 3.0 g / m 3 That is, the gas circulation 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 less, it 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 make the decontamination gas concentration inside the working space S reach the target value concentration.

[0121] In this startup process (S2), the decontamination gas is generated by the gas generation unit 20, and the decontamination gas is supplied from the supply tube 21 toward the gas dispersion unit 3. Here, the gas generation unit 20 determines the amounts of the respective chemical solutions that serve as raw materials necessary for the decontamination gas to reach the target concentration, and each chemical solution is placed in its respective container.

[0122] Also, in the startup process (S2), the decontamination gas is uniformly dispersed from the gas dispersion unit 3 toward the introduction space I. As a result, the decontamination gas can reach every corner of the introduction space I. Further, the decontamination gas spreads from the introduction space I into the interior of the work space S.

[0123] Even inside the work space S, since the decontamination gas is dispersed by the gas dispersion unit 3, the decontamination gas is more likely to spread. Also, by operating the air circulator provided inside the work space S, the decontamination gas can be further spread.

[0124] Also, in the startup process (S2), the air pump 6 is driven to create an air flow from the discharge port B1 of the safety cabinet B toward the gas circulation path 7. Also, in the recovery device 5, the switching valve 520 is opened, and the switching valves 500 and 510 are closed so that the air passes through the lower layer portion 52 of the recovery device 5.

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

[0126] As a result, even during the startup process (S2), it becomes easier for the decontamination gas to reach the work space S, the supply HEPA filter 12, the positive pressure plenum 15, the exhaust HEPA filter 11, and the space between the exhaust HEPA filter 11 and the discharge port B1, etc.

[0127] Also, when circulating air with the air pump 6, the control device controls the driving of the air pump 6, the needle valve 9a, and the needle valve 9b based on the measured value of the pressure flow meter 8a and the measured value of the pressure flow meter 8b, so that the pressure in the working space S can be adjusted and maintained uniformly.

[0128] Also, in the startup process (S2), when circulating the gas through the air pump 6 and the gas circulation path 7, the dispersion suction part 4 can spread the flow of the decontamination gas 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] Also, in the startup process (S2), the gas in the working space S is recovered by the gas generation part 20 through the recovery tube 22, the decontamination gas is adsorbed by the activated carbon to make fresh air, and then it is used again for the generation of the decontamination gas.

[0130] As a result, when the gas generation part 20 aerates for the generation of the decontamination gas, there is no need to newly introduce air from the external space, it is possible to prevent the sealed space from becoming positive pressure, and it is possible to prevent the decontamination gas from leaking to the outside. Also, since the gas will be circulated, the concentration of the decontamination gas in the sealed space can be efficiently increased.

[0131] Also, in this process, the concentration measuring mechanism measures the concentration of the decontamination gas inside the working space S. This measurement of the decontamination gas concentration is automatically performed at each set interval.

[0132] Also, in the startup process (S2), the generation and supply of the decontamination gas continue until the concentration of the decontamination gas inside the working space S rises and reaches the target concentration value. The target concentration value can be set as appropriate.

[0133] Also, when the concentration of the decontamination gas in the air inside the working space S reaches the value of the target concentration value, the driving of the gas generation part 20 is stopped, and the process proceeds to the next exposure process (S3).

[0134] Next, in a state where the supply of the decontamination gas is stopped, an exposure step (S3) of exposing the work space S to the decontamination gas is performed. In the exposure step (S3), with the introduced decontamination gas filling the work space S, the air pump 6 is driven in the same manner as in the rising step (S2), and the gas is circulated between the inside and outside of the safety cabinet B via the gas circulation path 7.

[0135] Also, in this step, the air circulator inside the work space S is operated to disperse the decontamination gas in the work space S. Also, if necessary, the safety cabinet B is driven.

[0136] Also, in the exposure step (S3), with the introduced decontamination gas filling the work space S, the CT value is continuously calculated based on the concentration measurement by the concentration measurement mechanism.

[0137] Also, when it is detected that the CT value has reached or exceeded the set threshold value, the exposure step (S3) ends and proceeds to the next recovery and cleaning step (S4).

[0138] In this exposure step (S3), the decontamination gas is allowed to act on the wall surface constituting the work space S, the top surface of the workbench 13, the introduction space I, the supply HEPA filter 12, the positive pressure plenum 15, the exhaust HEPA filter 11, and the space between the exhaust HEPA filter 11 and the exhaust port B1, etc., and the number of microorganisms adhering to these or floating in the space, etc., can be reduced.

[0139] Examples of the microorganisms to be sterilized and disinfected include bacteria, fungi, viruses, etc.

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

[0141] Subsequently, in the recovery and cleaning step (S4), the air inside the work space S is sucked to adsorb the decontamination gas contained in the air, and the decontamination gas concentration in the work space S is reduced to a concentration safe for the human body.

[0142] In this recovery and cleaning step (S4), 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.

[0143] At this time, first, the switching valve 500 is opened, the switching valves 510 and 520 are closed, and the air containing the decontamination gas is passed through the upper layer portion 50 of the recovery device 5.

[0144] If, by any chance, holes are formed in the exhaust HEPA filter 11 and the supply HEPA filter 12, and the positive pressure plenum 15 is contaminated with contaminants such as pathogenic microorganisms, and contaminants adhere to the crystalline zeolite filled in the upper layer portion 51 of the recovery device 5 during the decontamination step (S1), the contaminants can be inactivated by flowing the air containing the decontamination gas from the working space S to the upper layer portion 51.

[0145] After that, the switching valve 510 is opened, the switching valves 500 and 520 are closed, and air is passed through the middle layer portion 51 of the recovery device 5.

[0146] When passing through this middle layer portion 51, the decontamination gas contained in the sucked air is adsorbed by the activated carbon. Also, the air that has passed through the activated carbon returns to the inside of the working space S again.

[0147] In this step, the concentration measuring mechanism measures the concentration of the decontamination gas inside the working space S, and the measured value is monitored. In the recovery and cleaning step (S4), the recovery of the decontamination gas is continuously performed until the concentration of the decontamination gas in the air inside the working space S becomes less than the set concentration.

[0148] Also, when the concentration of the decontamination gas in the air inside the working space S becomes less than the set concentration, the recovery and cleaning step (S4) ends. In this state, a series of decontamination processes for the working space S are completed, and the safety cabinet B can be used.

[0149] Through the above process, a series of steps related to the decontamination operation using the decontamination mechanism A are performed.

[0150] Also, with reference to FIG. 7, another example of the process flow of the decontamination operation using the decontamination mechanism A to which the present invention is applied will be described.

[0151] In another example of the decontamination method shown in FIG. 7, unlike the method shown in FIG. 6 described above, a dehumidification step is not performed before the startup step, and the dehumidification step is performed after the exposure step and the recovery / washing step are completed.

[0152] In the series of steps shown in FIG. 7, there are a startup step (S5), an exposure step (S6), a recovery / washing step (S7), and a dehumidification step (S8). In the following description, the description of the parts common to the flow shown in FIG. 6 described above will be omitted, and the description will focus on the differences.

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

[0154] Next, in the recovery / washing step (S7), the air pump 6 is driven, and the air inside the work space S is sucked toward the recovery device 5 through the gas circulation path 7. Also, the sucked air opens the switching valve 510, closes the switching valves 500 and 520, and passes through the middle layer portion 51 of the recovery device 5.

[0155] When passing through this middle layer portion 51, the decontamination gas contained in the sucked air is adsorbed by the activated carbon. Also, the air that has passed through the activated carbon is returned to the inside of the work space S again.

[0156] In this process, the concentration measurement mechanism measures the decontamination gas concentration inside the work space S, and the measured value is monitored. In the recovery and cleaning process (S7), the decontamination gas is continuously recovered until the decontamination gas concentration in the air inside the work space S becomes less than the set concentration.

[0157] Furthermore, when the decontamination gas concentration in the air inside the work space S becomes less than the set concentration, the recovery and cleaning step (S7) is completed.

[0158] Subsequently, in a dehumidification step (S8), the work space S of the safety cabinet B is dehumidified by collecting water molecules contained in the air inside the work space S.

[0159] In this process, the air pump 6 is driven to suck the air inside the working space S into the recovery device 5 through the gas circulation path 7. The sucked air is 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] When the air passes through this upper layer portion 50, water molecules contained in the air are adsorbed by the crystalline zeolite, whereby the air is dehumidified and returned to the working space S.

[0161] In this step, the temperature, relative humidity, and absolute humidity of the internal environment of the work space S are measured by the concentration measurement mechanism, and each measurement value is monitored. In the dehumidification step (S8), the absolute humidity of the air inside the work space S is adjusted to 6 to 10 g / m 3 Keep the humidity below 10 to 30 minutes to maintain the workspace S in a low humidity state.

[0162] In this way, by carrying out a dehumidification process (S8) to dehumidify the work space S after the exposure process (S6) and the recovery / cleaning process (S7), the work space S can be made into a low-humidity environment in which the contents are less likely to corrode.

[0163] When the dehumidification step (S8) is completed, a series of decontamination processes for the work space S are completed, and the safety cabinet B can be used.

[0164] Also, through the above-described process flow, a series of steps related to the decontamination operation using the decontamination mechanism A can be performed.

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

[0166] In particular, not only inside the work space S, but also at the ends and peripheries of the exhaust HEPA filter 11, the positive pressure plenum 15, the ends and peripheries of the supply HEPA filter 12, or the introduction space I below the workbench 13, etc., the decontamination gas can be distributed to every corner, and a sufficient decontamination effect can be obtained.

[0167] As described above, the decontamination mechanism of the present invention allows the decontamination gas to be sufficiently distributed inside the apparatus to be decontaminated during decontamination, and an excellent decontamination effect can be obtained.

[0168] [Second Embodiment of the Present Invention] The second embodiment of the present invention will be described. The main difference between the decontamination mechanism A2 in the second embodiment of the present invention and the first embodiment of the present invention described above is that it has a mechanism for discharging the gas inside the safety cabinet based on the difference between the internal pressure of the safety cabinet (hereinafter referred to as "internal pressure") and the atmospheric pressure of the indoor space where the safety cabinet is installed (hereinafter referred to as "atmospheric pressure"). Also, the decontamination mechanism A2 uses chlorine dioxide as the decontamination gas.

[0169] Note that the internal structure of the safety cabinet B3 in the decontamination mechanism A2 is the same as the internal structure of the safety cabinet B1 in the first embodiment of the present invention described above, and a detailed description thereof will be omitted. Also, hereinafter, the description will focus on the differences from the first embodiment of the present invention.

[0170] As shown in FIG. 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 capable of discharging the air inside the main body to the outside of the main body.

[0171] Also, 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 member that transfers air when discharging gas from the inside of the main body of the safety cabinet B3 to the outside.

[0173] The internal pressure exhaust filter 104 is a member 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 configured by filling activated carbon.

[0174] Also, a cabinet internal pressure sensor 100 for measuring the internal pressure is installed inside the main body of the safety cabinet B3. Further, an atmospheric pressure sensor 102 for measuring the atmospheric pressure is provided in the indoor space where the safety cabinet B3 is installed.

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

[0176] Here, the gas discharge path 101 corresponds to the gas discharge path in the claims of the present application. Also, the control unit here corresponds to the gas discharge part in the claims of the present application, and the difference between the internal pressure of the safety cabinet and the atmospheric pressure corresponds to the internal and external differential pressure in the claims of the present application.

[0177] Also, the internal pressure exhaust filter 104 here corresponds to the exhaust recovery part in the claims of the present application.

[0178] Here, the control unit does not necessarily need to control 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. 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 that the control unit control 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, in order to sufficiently prevent leakage of decontamination gas from the inside to the outside of the main body, which occurs when decontamination gas is supplied to the inside of the safety cabinet B3 and the internal pressure increases.

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

[0180] The chlorine dioxide gas measurement optical path 115 is a component that measures the concentration of chlorine dioxide gas contained in the gas collected 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 whose chlorine dioxide gas concentration has been measured.

[0181] In addition, the chlorine dioxide gas measurement unit 111 is provided on a path consisting of an internal air collection tube 220 that transports gas inside the main body of the safety cabinet B3, and an internal air return tube 110 that transports gas that has passed through the chlorine dioxide gas measurement optical path 115 back into the main body of the safety cabinet B3.

[0182] In addition, a flow rate control valve 113 that adjusts the flow rate of gas passing through the chlorine dioxide gas measuring section 111 and a measuring section supply pump 112 that creates a flow of gas to the chlorine dioxide gas measuring section 111 are provided midway along the internal air sampling tube 220.

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

[0184] In addition, the decontamination mechanism A2 has a gas circulation path 7A (see FIG. 18). This gas circulation path 7A has the same function as the above-described gas circulation path 7. A circulation blower 70 and a circulation pressure release valve 71 are provided in the gas circulation path 7A.

[0185] Moreover, the circulation blower 70 is a member for generating a gas flow that circulates 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 for adjusting the blowing pressure of the circulation blower 70.

[0186] In addition, a dehumidification filter 72 and a recovery filter 73 are provided in the gas circulation path 7A.

[0187] Moreover, the dehumidification filter 72 allows the air in the working space to pass through 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, adsorbs the water molecules contained in the air to the crystalline zeolite, and is a part for dehumidifying the working space.

[0188] In addition, the recovery filter 73 is filled with activated carbon, and after exposing the working space to chlorine dioxide, it allows the air in the working space to pass through, adsorbs the chlorine dioxide to the activated carbon, and is a part for recovering it.

[0189] In addition, a filter effective switching valve 74, a dehumidification filter switching valve 75, and a recovery filter switching valve 76 are provided in the gas circulation path 7A.

[0190] Moreover, the filter effective switching valve 74 is a valve for switching the effectiveness or ineffectiveness of the dehumidification filter 72 and the recovery filter 73.

[0191] The dehumidifying filter switching valve 75 is a valve that switches between enabling and disabling the gas to pass only through the dehumidifying filter 72 or to pass the gas through both the dehumidifying filter 72 and the collection filter 73 .

[0192] The collection filter switching valve 76 is a valve that switches the collection filter 73 between enabled and disabled states.

[0193] The decontamination mechanism A2 also has a gas generator 200 (see FIG. 18). The gas generator 200 is a part that generates chlorine dioxide gas.

[0194] The gas generator 200 also includes a water injection tank 201 , a reactive acid tank 202 , a chlorous acid tank 203 , a reaction tank 207 , and a wastewater tank 208 .

[0195] Gas production section 200 also has a reaction tank water injection pump 204, a reaction acid supply pump 205, a chlorous acid supply pump 206, and a reaction tank drain pump 209. In gas production section 200, raw materials for chlorine dioxide are supplied from each tank to reaction tank 207, and chlorine dioxide is produced in reaction tank 207.

[0196] The inside of the reaction tank 207 is aerated by an aeration pump 221, and chlorine dioxide produced in the reaction tank 207 is supplied to the inside of the safety cabinet B3 via a 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 and controls the operation of the internal pressure exhaust pump 103, thereby maintaining 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 as chlorine dioxide is supplied, becoming a positive pressure relative to atmospheric pressure, and as the internal pressure increases, chlorine dioxide is prevented from leaking to the outside through the front opening of the safety cabinet B3, which is closed with tape or the like.

[0199] For example, when about 2.98 L of chlorine dioxide is supplied into a safety cabinet with an internal volume of about 576 L, the internal pressure rises by about 5.3 hPa. If the differential pressure between the internal pressure of the safety cabinet and the atmospheric pressure is about 5.3 hPa, a load of about 508.8 N (equivalent to about 51.9 kgf) is applied to the front panel of the safety cabinet with an area of about 0.96 m 2 to the power of 2.

[0200] Therefore, in the decontamination mechanism A2, while the control unit observes the difference between the internal pressure of the safety cabinet B3 and the atmospheric pressure in real time, by maintaining the internal pressure at a negative pressure with respect to the atmospheric pressure, leakage of chlorine dioxide from the inside of the safety cabinet B3 to the outside can be suppressed, and the load on the internal structure of the safety cabinet B3 due to the increase in the internal pressure can be reduced.

[0201] In addition, in the decontamination mechanism A2, similar to the above-described decontamination mechanism A, during decontamination, chlorine dioxide is sufficiently distributed inside the device to be decontaminated, and an excellent decontamination effect can be obtained.

[0202] As described above, the invention made by the present inventor has been specifically described based on the embodiments. However, it goes without saying that the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist thereof.

Example

[0203] The following examples will be described.

[0204] [Decontamination and Judgment by BI] Decontamination using the decontamination mechanism A to which the present invention is applied and decontamination without using the decontamination mechanism A were performed, and the effect of decontamination was judged by BI (biological indicator) installed at multiple locations inside the safety cabinet. The decontamination performed using the decontamination mechanism A is taken as Example 1. Also, on a day different from Example 1, the decontamination performed under the same conditions as Example 1 is taken as Example 2. Further, in the configuration of the decontamination mechanism A, the decontamination gas is supplied from the supply tube 21 to the introduction space I without providing the gas dispersion section 3, and the exhaust port B1 is directly connected to the gas circulation path 7 without providing the dispersion suction section 4 at the exhaust port B1. This mode is taken as Comparative Example 1. Also, on a day different from Comparative Example 1, the decontamination performed under the same conditions as Comparative Example 1 is taken as Comparative Example 2. Further, on a day different from Comparative Examples 1 and 2, the decontamination performed under the same conditions as Comparative Example 1 is taken as Comparative Example 3. Also, on a day different from Comparative Examples 1, 2, and 3, the decontamination performed under the same conditions as Comparative Example 1 is taken as Comparative Example 4. Furthermore, on the same day as Comparative Example 4, the decontamination performed under the same conditions as Comparative Example 1 as the second decontamination is taken as Comparative Example 5. Also, for Example 1 and Example 2, and Comparative Examples 1 to 5, decontamination was performed on the same safety cabinet for normal use.

[0205] The decontamination conditions in Example 1 and Example 2, and Comparative Examples 1 to 5 are as follows. Decontamination gas: Chlorine dioxide Fumigation time (time of the exposure step): 200 minutes Target CT value: 2,000 Target concentration: 600 ppm In addition, Fig. 5 shows a graph showing the change in the concentration of chlorine dioxide and the change in the CT value with the elapsed time in the working space S for the decontamination of Example 1.

[0206] Also, in the determination by BI, BI was installed at the following 9 locations inside the apparatus of the safety cabinet for decontamination, and after decontamination, BI was recovered and cultured in a medium for 48 hours to confirm the presence or absence of sterilization of B. atrophaeus, which is the indicator bacterium originally held by BI. Also, BI not installed inside the safety cabinet was used as a positive control. (Installation location of BI) 1. Left side position on the secondary side of the exhaust HEPA filter 11 2. Central position on the secondary side of the exhaust HEPA filter 11 3. Right side position on the secondary side of the exhaust HEPA filter 11 4. Left position of the positive pressure plenum 15 5. Right position of the positive pressure plenum 15 6. Left position on the primary side of the supply air HEPA filter 12 7. Right position on the primary side of the supply air HEPA filter 12 8. Left position of the introduction space I 9. Right position of the introduction space I 10. Positive control (not installed inside the safety cabinet) Note that the "secondary side of the filter" means the part where the air that has passed through the filter is located, and the "primary side of the filter" means the part where the air before passing through the filter is located.

[0207] In Example 1 and Example 2, for all of the installation locations 1 to 9 of BI, even when the BI was cultured for 48 hours after decontamination, no growth of B. atrophaeus retained in the BI was observed, and growth was observed only in the positive control. The decontamination effect was confirmed at all installation locations 1 to 9.

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

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

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

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

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

[0213] [Comparison of metal corrosion due to humidity environment during decontamination] The following test was conducted to confirm the effect of differences in humidity environment within the equipment space on metal corrosion when decontaminating the target equipment using the decontamination mechanism. In this test, six types of metal test pieces were prepared: aluminum, stainless steel, brass, lead, copper, and iron. Each was placed in an exposure test box to simulate decontamination targets, and treated under different conditions such as humidity in accordance with the following examples and comparative examples. The details of the metal test pieces are as follows: AS ONE Corporation Aluminum Metal Plate 50 x 100 x 0.5 (mm) Model Number: AZ551 AS ONE Corporation Metal Plate Stainless Steel (SUS430) 50 x 100 x 0.5 (mm) Model Number: SZ554 AS ONE Corporation Brass Metal Plate 50 x 100 x 1.0 (mm) Model Number: YZ152 AS ONE Corporation Lead Metal Plate 50 x 300 x 0.5 (mm) Model Number: GZ555 AS ONE Copper Metal Plate, 50 x 100 x 0.5 mm, Model Number: CZ553 Metal plate iron manufactured by Nippon Steel Corporation Product name: COLD ROLLED STEEL SHEET

[0214] Comparative Example 6: The inside of the exposure test box was set to a high-humidity environment (relative humidity: 94.9%, maximum absolute humidity: 19.5 g / m 3 ), decontamination was performed, and the decontamination gas was not recovered. Comparative Example 7: The inside of the exposure test box was set to a high-humidity environment (relative humidity: 90.4%, maximum absolute humidity: 18.5 g / m 3 ), decontamination was performed, and the decontamination gas was recovered. For lead and iron, the tests were conducted in a high-humidity environment (relative humidity: 84%, maximum absolute humidity: 16 g / m 3 ). Example 3: Before decontamination, the inside of the exposure test box was dehumidified to create a low-humidity environment (relative humidity: 49%, maximum absolute humidity: 8.6 g / m 3 ), and then decontamination was performed and the decontamination gas was recovered. For lead and iron, the tests were conducted in a low-humidity environment (relative humidity: 48%, maximum absolute humidity: 9.3 g / m 3 ). Comparative Example 8: No decontamination was performed inside the exposure test box (non-exposed). 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 with a target CT value of 1,100.

[0215] [Quantification of Residual Chlorine Amount] Metal corrosion is assumed to occur when chlorine in chlorine dioxide, a decontamination gas, adheres to the metal surface and reacts with oxygen in the air to form rust on the metal surface. Therefore, the metal test pieces subjected to Example 3 and Comparative Examples 6 to 8 were quantitatively analyzed for residual chlorine using an energy-dispersive micro-area fluorescence X-ray analyzer M4 (manufactured by Bruker AXS, Germany). Note that only in Comparative Example 6, tests were conducted on copper, brass, aluminum, and stainless steel. Here, when evaluating the metal test pieces using the energy-dispersive micro-area fluorescence X-ray analyzer M4, spectra derived from six elements, namely zinc (Zn), aluminum (Al), chlorine (Cl), chromium (Cr), iron (Fe), and copper (Cu), can be obtained. Therefore, the percentage (%) of the content of chlorine (Cl) detected from each metal test piece, with the total amount of the six elements set to 100%, was defined as the residual chlorine amount (%). In FIGS. 10 to 15, the results of Comparative Example 6, Comparative Example 7, Example 3, and Comparative Example 8 are shown from left to right, and the numerical values described in "Map measurement low value Cl" at the bottom of each figure indicate the values of the residual chlorine amount (%).

[0216] As shown in FIG. 10, in the aluminum test piece, the residual chlorine amount in Example 3 was as low as 0.01%.

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

[0218] As shown in FIG. 12, in the brass test piece, the residual chlorine amount in Example 3 was as low as 0.02%.

[0219] As shown in FIG. 13, in the lead test piece, the residual chlorine amount in Example 3 was 0.00% and it was not detected.

[0220] As shown in FIG. 14, in the copper test piece, the residual chlorine amount in Example 3 was as low as 0.01%.

[0221] As shown in FIG. 15, in the iron test piece, the residual chlorine amount in Example 3 was as low as 0.05%.

[0222] [Observation of metal corrosion] For the metal test pieces of Example 3 and Comparative Examples 6 to 8, the corrosion degree of the metal surface was observed using a polarizing microscope (manufactured by Leica Microsystems) by polarizing microscope reflected polarization (differential interference contrast) method. Note that, for Comparative Example 6 only, tests were conducted on copper, brass, aluminum, and stainless steel. In addition, Figs. 16 and 17 show, from left to right, the results of Comparative Example 6, Comparative Example 7, Example 3, and Comparative Example 8. In addition, Fig. 16 shows the results for copper, brass, aluminum, and stainless steel, and Fig. 17 shows the results for lead and iron.

[0223] 16, no void-like patterns resulting from metal corrosion were observed on the surfaces of the copper, brass, aluminum, and stainless steel metal test pieces of Example 3, 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 void-like patterns resulting from metal corrosion were observed on the surfaces of the copper, brass, aluminum, and stainless steel metal test pieces.

[0224] 17, no void-like patterns resulting from metal corrosion were observed on the surfaces of the lead and iron metal test pieces of Example 3, and the surfaces were similar to those of Comparative Example 8, which was not decontaminated. On the other hand, in Comparative Example 7, multiple void-like patterns resulting 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 HEPA filter 13 Workbench 14 Front Panel 15 Positive pressure plenum 16 Blower 17 Negative pressure plenum S workspace I. Introduction space B1 outlet 2 Gas supply section 20 Gas generation section 21 Supply tube 22 Collection tube 3 Gas dispersion section 30 Connection 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 Switching Valve 51 Middle floor 510 Switching valve 52 Lower part 520 Switching Valve 6. Air pump 7 Gas circulation path 8a Pressure flow meter 8b Pressure flow meter 9a Needle valve 9b Needle valve B2 supply port S10 (covered) space A2 Decontamination mechanism B3 Biosafety Cabinet 100 Cabinet internal air pressure sensor 101 Gas Exhaust Route 102 Atmospheric pressure sensor 103 Internal pressure exhaust pump 104 Internal pressure exhaust filter 110 Internal air return tube 110 111 Chlorine dioxide gas measuring unit 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 tank 202 Reactive Acid Tank 203 Chlorite Tank 204 Reactor water injection pump 205 Reaction acid supply pump 206 Chlorite supply pump 207 Reactor 208 Drainage Tank 209 Reactor drainage pump 220 Internal air collection tube 221 Aeration pump 222 Gas supply tube 7A Gas circulation path 70 Circulation blower 71 Circulation pressure release valve 72 Dehumidifying filter 73 Collection filter 74 Filter active switching valve 75 Dehumidifying filter switching valve 76 Recovery filter switching valve

Claims

1. A decontamination mechanism for decontaminating a predetermined device having a main body with a working space formed therein and an exhaust filter for sterilizing the air in the working space before exhausting it from an exhaust portion to the outside of the main body, comprising: A decontamination gas supply path for supplying decontamination gas supplied from the outside of the main body toward an introduction space that is formed inside the main body and communicates with the working space; A gas dispersion part that is a cylindrical body disposed in the introduction space and connected to the decontamination gas supply path, and has a plurality of hole parts formed on its outer peripheral surface; A closing plate that is a plate-like body for closing the exhaust portion, and has a plurality of ventilation parts formed therethrough; A lid part that is an umbrella-shaped body covering a region where the plurality of ventilation parts of the closing plate are formed, whose end is connected to the edge of the closing plate, and has an opening formed at the top; A gas circulation path that connects the opening and a supply port formed in the main body and communicating with the working space to form 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 dehumidifying part provided on the gas circulation path for dehumidifying the air in the working space before or after performing the decontamination; And a recovery part provided on the gas circulation path for recovering the decontamination gas from the air in the working space that has been exposed to the decontamination gas for a certain period of time. Decontamination mechanism.

2. When the gas dispersion part forms a closed path in a plan view and the entire range of the closed path is divided into a region close to the connection part connected to the decontamination gas supply path and a region far from the connection part, the number of the hole parts in the far region is formed to be more than the number of the hole parts in the near region. The decontamination mechanism according to Claim 1. The decontamination mechanism according to Claim 1.

3. The decontamination mechanism according to Claim 2, wherein the size of the hole parts in the far region is formed to be larger than the size of the hole parts in the near region. The decontamination mechanism according to Claim 2.

4. The closing 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 8% or less. The decontamination mechanism according to Claim 1 or Claim 2. The decontamination mechanism according to Claim 1 or Claim 2.

5. A recovery device having a dehumidifying part layer provided with the dehumidifying part, a recovery part layer provided with the recovery part, and a switching part capable of switching a flow path passing through the dehumidifying part layer and a flow path passing through the recovery part layer on the gas circulation path. The decontamination mechanism according to claim 1 or claim 2.

6. The air pump can variably control the flow rate of the gas, A first measuring unit provided between the opening and the air pump on the gas circulation path for measuring the flow rate and pressure of the gas; A first adjusting unit 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 provided between the air pump and the supply port on the gas circulation path for measuring the flow rate and pressure of the gas; A second adjusting unit provided between the air pump and the supply port on the gas circulation path for adjusting the flow rate and pressure of the gas, Based on the measured values of the first measuring unit and the second measuring unit, the air pump, the first adjusting unit, and the second adjusting unit are controlled to uniformly maintain the pressure in the working space. The decontamination mechanism according to claim 1 or claim 2.

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

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

9. The predetermined device is a safety cabinet or an isolator for animal breeding. The decontamination mechanism according to claim 1 or claim 2.

10. Based on the measurement result of the internal and external differential pressure, which is the difference between the pressure of the gas inside the main body and the pressure of the gas outside the main body, a gas discharge unit is provided to discharge the gas inside the main body to the outside through a gas discharge path. The decontamination mechanism according to claim 1 or claim 2.

11. An exhaust gas recovery unit is provided on the gas discharge path for recovering the decontamination gas from the discharged gas. The decontamination mechanism according to claim 11.

12. The gas discharge unit discharges the gas so as to maintain the pressure of the gas inside the main body at a positive pressure of 1 hPa or less with respect to the pressure of the gas outside the main body. The decontamination mechanism according to claim 10.

13. The gas discharge unit discharges the gas so as to maintain the pressure of the gas inside the main body at a negative pressure with respect to the pressure of the gas outside the main body. The decontamination mechanism according to claim 10.

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