Safety Operating Devices

Abstract

This invention provides a safe operating device for safety cabinets or fume hoods, etc., which incorporates multiple HEPA filters in the exhaust system to minimize the depth of the equipment and save space while limiting and suppressing external leakage of pollutants to zero. The safe operating device includes: a working space (12); a front gate (13) covering a portion of an opening on the front of the working space; a working opening (17) located below the front gate, allowing the operator to insert their hand for operation; a rear inlet (18) located at the lower rear of the working space for drawing in air from the working space; and an exhaust flow path (30) located at the rear of the rear of the working space for exhausting air from the working space. The safe operating device is characterized in that a first HEPA filter (31) for exhaust is longitudinally arranged behind the rear inlet (18) in the exhaust flow path, and a second HEPA filter (32) for exhaust is longitudinally arranged downstream of the first HEPA filter in the exhaust flow path.

Description

Technical Field

[0001] This invention relates to safety operating devices such as safety cabinets and fume hoods that enable operators to work safely when handling hazardous substances such as highly reactive materials. Background Technology

[0002] Safety cabinets are used in pharmaceutical development and research on pathogens such as viruses to protect workers and samples. Inside the safety cabinet, to prevent contaminants from escaping the equipment, the air in the work area handling the contaminants is filtered using a HEPA (High Efficiency Particulate Air) filter, and the air, now free of contaminants, is exhausted outside the equipment.

[0003] As an example, in Figure 10 The image shows the "chemical hazardous materials response cabinet" described in Patent Document 1. In the chemical hazardous materials response cabinet 100, a pre-filter 111 is provided at the back of the work space 103, and a HEPA filter 112 is provided below the work space 103. Inflow air 107, drawn in from the work opening 106 below the front gate 104, is drawn in along with contaminants 110 within the work space through the pre-filter 111. The contaminants 110 are removed by the HEPA filter 112, and the air is discharged outside the device through the exhaust port 108 by the blower 105. Furthermore, a HEPA filter cover 113 and a plastic bag mounting flange 116 are provided below the work space 103 and on the front side of the HEPA filter 112, and a plastic bag 115 is mounted thereon. When replacing a HEPA filter 112 that is contaminated with pollutants or dust, remove the HEPA filter cover 113, pull out the plastic bag 115 housed inside the plastic bag mounting flange 116, and remove the HEPA filter 112 through the plastic bag 115. The removed HEPA filter 112 is placed inside the plastic bag 115, cut and sealed using a cutting and sealing machine 118. (Patent Document 1, see also) Figure 6 ).

[0004] In addition, ventilation rooms (local exhaust systems, fume hoods) are also used for safety when handling hazardous substances.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent Application Publication No. 2013-160474 Summary of the Invention

[0008] The technical problem that the invention aims to solve

[0009] In a biosafety cabinet, HEPA filters gradually become clogged due to filtering contaminants and dust, requiring replacement. When replacing HEPA filters, safety must be ensured to prevent contaminants from affecting the operator. In cases involving pathogens such as viruses or cells, sterilization can create a safe environment. However, when handling highly reactive substances such as anticancer drugs that cannot be sterilized, as described in Patent Document 1, the HEPA filter is wrapped in a plastic bag and removed from the device in a sealed manner.

[0010] Furthermore, in the biosafety cabinet, when handling highly toxic substances, contaminated air is passed twice through exhaust HEPA filters, thereby exhausting non-toxic air. Two exhaust HEPA filters are installed; the first HEPA filter removes over 99.97% of contaminants, and the second HEPA filter removes almost 100% of contaminants.

[0011] However, installing two HEPA filters (first and second) increases the installation area, making it difficult to save space. Furthermore, when replacing the HEPA filters, if the contaminants collected by the HEPA filters are re-emitted, there is a possibility that the contaminants may be discharged outside the machine unfiltered.

[0012] The "chemical hazardous materials response cabinet" described in Patent Document 1 does not take into account space-saving installation area or external leakage caused by the re-spread of pollutants during HEPA filter replacement.

[0013] The purpose of this invention is to provide a space-saving safety operating device for safety cabinets, ventilation rooms, etc., which minimizes the depth of the equipment by setting multiple HEPA filters in the exhaust system to limit and suppress the leakage of pollutants to zero.

[0014] Technical solutions for solving technical problems

[0015] To address the aforementioned technical problems, an example of the "safe work device" of the present invention is provided. A safe work device includes: a work space; a front gate covering a portion of an opening on the front of the work space; a work opening located below the front gate, allowing an operator to insert their hand into the work opening for work; a rear inlet located at the lower part of the back of the work space for drawing in air from the work space; and an exhaust path located at the rear of the back of the work space for exhausting air from the work space. The safe work device is characterized in that: a first HEPA filter for exhaust is longitudinally arranged behind the rear inlet within the exhaust path; and a second HEPA filter for exhaust is longitudinally arranged downstream of the first HEPA filter within the exhaust path.

[0016] In addition, another example of the "safety work device" of the present invention is characterized in that, during normal operation, a pre-filter for recovering larger dust particles is installed at the rear port, configured such that the pre-filter can be removed when replacing the first HEPA filter, and the bag-in-bag-out type first HEPA filter replacement port is installed at the rear port.

[0017] In addition, another example of the "safety work device" of the present invention is characterized in that, further, a bag-in-bag-out type second HEPA filter replacement port can be installed on the working space side of the second HEPA filter on the back side of the working space.

[0018] Invention Effects

[0019] According to the present invention, a first HEPA filter for exhaust is arranged longitudinally on the rear side of the rear opening at the back of the working space, and a second HEPA filter is arranged longitudinally on the downstream side of the first HEPA filter in the exhaust flow path. By reversing the intake and exhaust directions between the longitudinally arranged HEPA filters, the depth width of the equipment can be minimized to save space, and multiple exhaust HEPA filters can be installed.

[0020] In addition, the structure that allows the upstream side of the first HEPA filter to be located below when it is replaced and the upstream side of the second HEPA filter to be located above when it is replaced can suppress the re-spread of pollutants during HEPA filter replacement, which could lead to leakage of pollutants to the exhaust side.

[0021] The technical issues, structures, and effects other than those described above will become clearer through the following description of the implementation methods. Attached Figure Description

[0022] Figure 1This is a schematic diagram illustrating an example of a safety cabinet equipped with two HEPA filters for exhaust.

[0023] Figure 2 This is a schematic diagram showing another example of a safety cabinet equipped with two HEPA filters for exhaust.

[0024] Figure 3 This is a front view of the ventilation chamber in Example 1.

[0025] Figure 4 This is a right-side view of the ventilation chamber in Example 1.

[0026] Figure 5 Is Figure 4 The image shows the plastic bag being removed from the bottom.

[0027] Figure 6 This is a diagram representing a plastic bag.

[0028] Figure 7 This is a right-side view of the ventilation chamber in Example 2.

[0029] Figure 8 Is Figure 7 The image shows the plastic bag that was removed from the top.

[0030] Figure 9 This is a right-side view of the safety cabinet in Example 3.

[0031] Figure 10 This diagram illustrates an example of an existing chemical hazardous materials handling cabinet. Detailed Implementation

[0032] Before describing embodiments of the present invention, a conventional safety cabinet equipped with two exhaust HEPA filters for detoxifying polluted air will be described.

[0033] Figure 1 The image shows an example of a safety cabinet equipped with two HEPA filters for exhaust. The figure is a schematic side cross-sectional view of the safety cabinet from the right.

[0034] Inside the safety cabinet 10, there is a working space 12 formed by a front gate 13. An intake fan 14 is located above the working space 12, supplying clean air, which has passed through an intake HEPA filter 15, into the working space 12. An exhaust passage 30 is located at the back of the working space 12, and a first exhaust filter 31 is installed in the exhaust passage 30. An exhaust fan 33 is located above the safety cabinet 10, and a second exhaust filter 32 is installed in the building's exhaust duct system or the machine room. When air supplied from above to the working space 12 and air drawn into the working space 12 from the working opening 17 pass through a pre-filter 19 and circulates in the exhaust passage 30, contaminants 40 are removed by the first HEPA filter 31 and the second HEPA filter 32.

[0035] However, the second HEPA filter 32 is located above the safety cabinet 10. The second HEPA filter 32 needs to be stored in a separate case from the safety cabinet. In addition, the replacement is a high-altitude operation, which is more difficult.

[0036] Figure 2 This is another example of a safety cabinet equipped with two HEPA filters for exhaust. The figure shows a simplified side cross-section of the safety cabinet from the right.

[0037] and Figure 1 The difference between the safety cabinets is that instead of installing a second HEPA filter on top of the safety cabinet 10, a second HEPA filter 32 is installed in the exhaust flow path 30 of the safety cabinet 10.

[0038] However, with Figure 1 Similarly, in safety cabinets, the HEPA filters are arranged laterally. In order to suppress the flow rate below the level required to maintain the capture efficiency of the HEPA filters, the depth dimension must be increased, thus requiring an increase in the depth of the equipment.

[0039] The present invention provides a method for arranging multiple HEPA filters for exhaust in a longitudinal (vertical) direction. By creating an airflow that reverses the intake and exhaust directions between the HEPA filters arranged in the longitudinal row, the depth of the equipment can be minimized and space can be saved. In addition, a safety operation device such as a safety cabinet or ventilation room is considered to suppress external leakage caused by the re-spread of pollutants when replacing HEPA filters.

[0040] The embodiments of the present invention will now be described with reference to the accompanying drawings. However, the present invention is not limited to the description of the embodiments shown below. Those skilled in the art will readily understand that modifications can be made to the specific structure without departing from the spirit and essence of the invention.

[0041] Furthermore, in the figures used to illustrate the embodiments, the same names and reference numerals are used to label the same constituent elements, and repeated descriptions are omitted.

[0042] Example 1

[0043] Example 1 is an example of using the present invention in a ventilation room as a safety work device. Figures 3-5 This refers to the ventilation chamber of Embodiment 1 of the present invention. Figure 3 This is a front view of the ventilation chamber in Example 1. Figure 4 This is the right-side view. Figure 4 In the diagram, the removed plastic bag is indicated by a two-dot underline. Additionally, Figure 5 Is Figure 4 The image shows the plastic bag being removed from the HEPA filter replacement port on the lower side of the ventilation chamber.

[0044] like Figure 4 As shown, a workspace 12 is located inside the ventilation chamber 11. A vertically movable front gate 13 is located on the front of the workspace 12, through which the operator 50 extends their hand to perform tasks via a work opening 17 below the front gate 13. An exhaust flow path 30 is located on the rear side of the workspace 12 in a vertical direction, and two HEPA filters for exhaust are installed in the exhaust flow path 30. Furthermore, although not shown, [the following is a description of a system / facility]... Figure 2 Similarly, the safety cabinet described above has an exhaust fan 33 installed above the ventilation chamber 11.

[0045] As a characteristic structure of the ventilation chamber in this embodiment, the first HEPA filter 31 for exhaust is arranged longitudinally (vertically) near the rear opening 18 of the back of the work space 12. That is, a pre-filter 19 for removing larger dust particles is provided at the rear opening 18 at the lower part of the back of the work space 12, and the first HEPA filter 31 is arranged longitudinally near and parallel to the pre-filter 19. In the exhaust flow path 30, a second HEPA filter 32 for exhaust is arranged longitudinally (vertically) in the same plane where the first HEPA filter 31 is provided. On the exhaust side behind the first HEPA filter 31, along the rear wall of the ventilation chamber, a flow path is provided to the intake side behind the second HEPA filter 32, which is a reverse flow path 30a that reverses the intake and exhaust directions. By arranging the two exhaust HEPA filters longitudinally, the depth dimension of the equipment can be minimized. Here, in normal use, the pre-filter 19 is provided at the rear opening 18. When replacing the first HEPA filter, the pre-filter 19 is removed to set up the first HEPA filter replacement port 34. The first HEPA filter replacement port 34 is installed only when replacing the HEPA filter, thereby minimizing the installation space of the workspace 12.

[0046] Air supplied to the workspace 12 is drawn in only through the work opening 17 and flows through the exhaust path 30 via the rear opening 18. Furthermore, pollutants 40 within the workspace are filtered and removed by the first HEPA filter 31 and the second HEPA filter 32.

[0047] A pre-filter 19 is provided at the rear opening 19, located in front of the first HEPA filter 31 for exhaust and at the lower rear wall of the work space 12. The first HEPA filter can be replaced by replacing the mold with the pre-filter 19 and the first HEPA filter replacement port 34 with a plastic bag. Similarly, a bag-in-bag-out type second HEPA filter replacement port 35 is provided in front of the second HEPA filter 32 and at the rear wall of the work space 12 for replacing the second HEPA filter, with the plastic bag folded and stored. The second HEPA filter replacement port 35 is located on the upper side of the work space 12 and, unlike the first HEPA filter replacement port 34, can always be installed without causing inconvenience to the operation.

[0048] Figure 5 This diagram shows the state where, for the purpose of replacing the first HEPA filter 31, a first HEPA filter replacement port 34 is installed at the rear opening 18, and a plastic bag 37 is pulled out from the first HEPA filter replacement port 34. When replacing the HEPA filter, the first HEPA filter replacement port 34 with a plastic bag is installed instead of the mold that fixes the pre-filter 19. The plastic bag 37 is then pulled out from the first HEPA filter replacement port 34, and the first HEPA filter 31 is removed through the plastic bag. At this time, if the work is performed while the exhaust fan on the building side is running, the work space 12 becomes negative pressure, preventing the contaminant 40 from leaking towards the worker 50. Furthermore, as shown by reference numeral 31', the first HEPA filter is tilted to collect the plastic bag 37. And, although not shown, the portion of the plastic bag containing the HEPA filter is cut using a cutting and welding machine, sealing the HEPA filter 31 within the plastic bag 37.

[0049] Figure 6 This is an example of a diagram showing the removal of a plastic bag from the changing slot. For example... Figure 6 As shown in (a), the plastic bag 37 is removed from its folded state. And, as... Figure 6 As shown in (b), the HEPA filter 31 is housed in a plastic bag 37. Then, the portion of the plastic bag 37 containing the HEPA filter is cut off and heat-fused to seal the HEPA filter 31 in the plastic bag 37.

[0050] According to this embodiment, the first HEPA filter 31 for exhaust is arranged longitudinally near the rear opening 18 of the back of the work space, and the second HEPA filter 32 for exhaust is arranged longitudinally in the same plane as the first HEPA filter 31 for exhaust, thereby minimizing the depth of the equipment.

[0051] In addition, the most contaminated first HEPA filter 31 is arranged longitudinally at the rear port 18 near the back of the work space, and the first HEPA filter replacement port 34 is installed at the rear port 19 during replacement. This allows the most contaminated first HEPA filter 31 to be replaced without the contaminated surface facing upwards, and can suppress the re-spread of pollutants that could lead to leakage of pollutants to the exhaust side.

[0052] Furthermore, on the intake side of the second HEPA filter 32 used for exhaust, contaminants 40 that were not captured by the first HEPA filter 31 used for exhaust may adhere to it. When replacing the second HEPA filter 32 used for exhaust, there is a possibility that the second HEPA filter 32 may vibrate and scatter contaminants due to disassembly or removal of the installation parts. However, since the contaminated surface of the second HEPA filter 32 faces the space on the side of the first HEPA filter 31, i.e., the rear wall of the ventilation chamber, even if contaminants are scattered, they will leak into the reverse flow path 30a along the rear wall of the ventilation chamber and fall downwards. Therefore, by removing the second HEPA filter after the scattered contaminants have fallen, it is possible to prevent the contaminants from being discharged in their original state.

[0053] Furthermore, a bag-in, bag-out replacement port 34 is provided on the working space side of the first HEPA filter 31 for exhaust. By storing the first HEPA filter 31 in a plastic bag 37, the re-spread of contaminants during HEPA filter replacement can be prevented, enabling safe and efficient replacement. The same structure applies to the second HEPA filter 32 for exhaust.

[0054] Example 2

[0055] Figure 7 and Figure 8 The diagram shows the ventilation chamber of Embodiment 2 of the present invention. Figure 7 This is a right-side view of the ventilation chamber in Example 2. Figure 7 In the diagram, a two-dot underline represents the plastic bag that was taken out. Additionally, Figure 8 Is Figure 7 The diagram shows the removal of a plastic bag from the HEPA filter replacement port on the upper side of the ventilation chamber. In this embodiment, the first HEPA filter 31 and the second HEPA filter 32 for exhaust are not mounted on the same plane, but are positioned at different locations, and the HEPA filter replacement port 35 of the second HEPA filter 32 is arranged at an angle.

[0056] like Figure 7 As shown, a first HEPA filter 31 is longitudinally arranged at the rear opening 18 near the back of the work space 12. Above the first HEPA filter 31, the mounting surface of a second HEPA filter 32 is arranged at a position offset from the work space 12, and the HEPA filter replacement port 35 of the second HEPA filter 32 is arranged at an angle so that its upper part is inclined towards the work space 12.

[0057] Figure 8 The diagram shows the plastic bag 37 being pulled out to replace the second HEPA filter. When replacing the second HEPA filter 32, the plastic bag 37 is pulled out, and the second HEPA filter 32 is removed by tilting it forward. Then, the removed second HEPA filter 32 is moved downwards and stored in the plastic bag 37. Furthermore, although not shown, the portion of the plastic bag 37 containing the HEPA filter is cut off, and heat-sealed to seal the HEPA filter 32 within the plastic bag 37.

[0058] The replacement of the first HEPA filter 31 and other structures are the same as those in the ventilation chamber of Example 1.

[0059] According to this embodiment, by staggering the second HEPA filter 32's arrangement facing the work space 12, as shown in the figure, the flow path from the first HEPA filter 31 to the second HEPA filter 32 can be widened, airflow resistance can be suppressed, and energy-saving effects can be expected. Furthermore, by tilting the second HEPA filter replacement port 35 so that its upper part is inclined towards the work space 12, it becomes easier to store the second HEPA filter 32 in the plastic bag 37, improving workability when replacing the HEPA filter.

[0060] In the above embodiments, a full exhaust ventilation chamber was described in which air drawn in from outside the device passes through the working space, pollutants are removed by a HEPA filter, and all air is exhausted to the outside of the device. The present invention can also be applied to a partial exhaust device with a similar full exhaust structure that is used to process organic solvents or specific chemical substances.

[0061] Example 3

[0062] Example 3 is an example of using the present invention in a safety cabinet as a safe working device. Figure 9 This refers to the safety cabinet of Embodiment 3 of the present invention. Figure 9 This is a cross-sectional view of the right side of the safety cabinet in Example 3.

[0063] like Figure 9As shown, the safety cabinet 10 has a workspace 12 inside. An intake fan 14 is located above the workspace 12, supplying clean air, which has passed through an intake HEPA filter 15, into the workspace 12. A vertically movable front gate 13 is located at the front of the workspace 12, through which the operator 50 inserts their hand via a work opening 17 below the front gate 13 to perform tasks. An exhaust passage 30 is located vertically at the rear of the workspace 12, and two exhaust HEPA filters are installed in the exhaust passage 30. An exhaust fan 33 is located at the outlet of the exhaust passage 30.

[0064] In this embodiment of the safety cabinet, the exhaust HEPA filter configuration is the same as that of the ventilation chamber in Embodiment 1. Specifically, the first exhaust HEPA filter 31 is arranged longitudinally (vertically) near the rear opening 18 of the work space 12. Furthermore, in the exhaust flow path 30, a second exhaust HEPA filter 32 is arranged longitudinally (vertically) on the same plane as the plane where the first HEPA filter 31 is located. Along the rear wall of the safety cabinet, on the exhaust side behind the first HEPA filter 31, an exhaust flow path is provided facing the intake side behind the second HEPA filter 32, forming a reverse flow path 30a that reverses the intake and exhaust directions. By arranging the two exhaust HEPA filters longitudinally, the depth dimension of the equipment can be minimized.

[0065] Air supplied from above the workspace 12 and air drawn in from the work opening 17 flow through the rear opening 18 in the exhaust path 30. Furthermore, pollutants 40 within the workspace are removed by the first HEPA filter 31 and the second HEPA filter 32 and exhausted to the outside of the device.

[0066] In the safety cabinet of this embodiment, the replacement of the first HEPA filter 31 and the second HEPA filter 32 for exhaust can be performed in the same manner as in the ventilation chamber of Embodiment 1. That is, when replacing the first HEPA filter, the pre-filter 19 is removed from the rear opening 18, the first HEPA filter replacement port 34 is provided, and the first HEPA filter 31 is stored in the plastic bag 37. Similarly, when replacing the second HEPA filter 32, the plastic bag 37 is pulled out from the second HEPA filter replacement port 35, and the second HEPA filter 32 is stored in the plastic bag 37.

[0067] According to this embodiment, in the safety cabinet, a first HEPA filter for exhaust is arranged longitudinally on the rear side of the rear opening provided at the back of the work space, and a second HEPA filter is arranged longitudinally in the exhaust flow path and downstream of the first HEPA filter. The intake and exhaust directions are reversed between the longitudinally arranged HEPA filters, thereby minimizing the depth of the equipment and saving space, and multiple exhaust HEPA filters can be installed.

[0068] In addition, the structure that allows the upstream side of the first HEPA filter to be located below the contaminated side during replacement, and the upstream side of the second HEPA filter to be located above the contaminated side during replacement, can suppress the leakage of contaminants to the exhaust side caused by the re-spreading of contaminants during HEPA filter replacement.

[0069] In this embodiment, a fully exhaust-type safety cabinet is described, in which air drawn in from outside the device passes through the work space, pollutants are removed by a HEPA filter, and all air is exhausted outside the device. However, the present invention can also be used in a circulating-type safety cabinet, in which a portion of the exhaust air is returned to the work space, thereby circulating the air.

[0070] Alternatively, in the safety cabinet, similar to the ventilation chamber in Embodiment 2, a first HEPA filter 31 may be longitudinally arranged at the rear opening 18 near the back of the work space 12, and a second HEPA filter 32 may be longitudinally arranged above the first HEPA filter 31 at a position offset towards the work space 12, with the HEPA filter replacement port 35 of the second HEPA filter 32 inclined towards the work space 12.

[0071] Furthermore, the present invention is not limited to the embodiments described above and can include various modifications. For example, the above embodiments are detailed descriptions provided for ease of understanding of the present invention and are not necessarily limited to having all the structures described. Additionally, a portion of the structure of one embodiment can be replaced with the structure of another embodiment, and the structure of another embodiment can be added to the structure of one embodiment. Furthermore, regarding a portion of the structure of each embodiment, additional structures can be added, deleted, or replaced.

[0072] Explanation of reference numerals in the attached figures

[0073] 10 Safety Cabinets

[0074] 11 Ventilation Room

[0075] 12 Workspace

[0076] 13 Front gate

[0077] 14. Intake fan

[0078] 15 HEPA filter for air intake

[0079] 17. Working opening

[0080] 18 Rear Mouth

[0081] 19 Pre-filter

[0082] 30 Exhaust Flow Path

[0083] 30a is a reverse flow path that reverses the intake and exhaust directions.

[0084] 31 HEPA filter for first exhaust

[0085] 32 Secondary exhaust HEPA filter

[0086] 33 Exhaust Fan

[0087] 34 First HEPA filter replacement port

[0088] 35 Second HEPA filter replacement port

[0089] 37 Plastic bags

[0090] 40 pollutants

[0091] 50 workers.

Claims

1. A safe working device, comprising: Workspace; A front gate that covers a portion of the opening on the front of the work space; The operation opening is located on the lower side of the front gate, allowing the operator to insert their hand into the operation opening to perform the operation; A rear inlet located at the lower rear of the work space for drawing in air from the work space; and An exhaust flow path is provided on the rear side of the back of the work space for discharging air from the work space. The safety operation device is characterized in that: A first HEPA filter for exhaust is arranged longitudinally on the rear side of the rear inlet within the exhaust flow path, and a second HEPA filter for exhaust is arranged longitudinally on the downstream side of the first HEPA filter within the exhaust flow path. On the exhaust side of the first HEPA filter, there is a reverse flow path that runs along the back of the safety cabinet toward the intake side of the second HEPA filter, reversing the intake and exhaust directions.

2. The safe operating device as described in claim 1, characterized in that: The second HEPA filter is configured on the same plane as the surface on which the first HEPA filter is disposed.

3. The safe operating device as described in claim 1, characterized in that: The second HEPA filter is disposed offset from the side of the work space relative to the surface where the first HEPA filter is disposed.

4. The safe operating device as described in claim 1, characterized in that: During normal operation, a pre-filter for recovering larger dust particles is installed at the rear inlet. The device is configured to allow the pre-filter to be removed when replacing the first HEPA filter, and to install the bag-in-bag-out type first HEPA filter replacement port at the rear port.

5. The safe operating device as described in claim 4, characterized in that: When replacing the first HEPA filter, the first HEPA filter is stored in a plastic bag with the contaminated side facing down.

6. The safe operating device as described in claim 1, characterized in that: The second HEPA filter replacement port, configured to be installed on the working space side of the second HEPA filter on the back side of the working space, is a bag-in-bag-out type.

7. The safe operating device as described in claim 6, characterized in that: When replacing the second HEPA filter, the second HEPA filter is stored in a plastic bag with the clean side facing down.

8. The safe operating device as described in claim 6, characterized in that: The second HEPA filter replacement port is positioned at an angle, with the upper part tilted towards the side of the work space.

9. The safe operating device as described in claim 1, characterized in that: The safe working device is a safety cabinet or a ventilated room.

Images