JP2013085994A - Safety cabinet - Google Patents

Abstract

【Task】
When a device such as an analyzer is installed, installed, and fixed in the work space of the safety cabinet, the wind speed and airflow state of the suction airflow (inflow airflow) formed in the work opening is known to the analyzer. Provide a safety cabinet that is not affected by the installation position or size.
[Solution]
An air suction port is provided below the work opening of the safety cabinet, and the air flow path sucked from the air suction port is connected to the flow path provided on the side wall surface of the work space connected to the air blowing means, and the air suction port. The space with the mouth was constructed so that the central part was shallow in the vertical direction and gradually deepened as it went to both sides. In addition, a fan is provided near the center of the space having an air suction port provided below the work opening.
[Selection] Figure 2

Description

  The present invention relates to a safety cabinet, and more particularly to a safety cabinet in which devices such as analyzers and observation devices can be incorporated in a safety cabinet for research of infectious diseases and development of pharmaceutical products.

  The safety cabinet draws air outside the safety cabinet from the work opening below the front shutter formed in the front of the work space, forms an air barrier, and physically creates the work space of the safety cabinet and the atmosphere outside the safety cabinet. Is shut off. The air sucked from the work opening passes through the inside of the safety cabinet, and removes infectious substances together with dust by an exhaust HEPA filter installed in the safety cabinet, and is exhausted out of the safety cabinet as clean air. The air blowing means for guiding air from the work opening to the exhaust HEPA filter may be provided inside the safety cabinet device or may be installed outside the safety cabinet device.

  In addition to the exhaust HEPA filter, an air supply HEPA filter is installed in the upper part of the work space, and when the air purified by the blowing means is supplied to the work space, the work space is supplied with aseptic air. Operation becomes possible. In the case of a class II cabinet for measures against biohazards, there is a case where a chamber for applying pressure to flow air to the exhaust HEPA filter and the air supply HEPA filter is shared, and a blower is attached to the chamber to supply air. Many.

  With the above configuration, the safety cabinet is configured so that aseptic operations are performed in the work space, and at the same time, the infectious substance handled in the work space does not leak out of the safety cabinet by the air barrier at the work opening and the exhaust HEPA filter.

  In the work space of the safety cabinet, the work of handling the device includes the work of opening the lid of the centrifuge. In the centrifuge, since the infectious experimental material is rotationally agitated, a large amount of droplets (aerosol) is generated inside. Furthermore, at the instant when the lid of the centrifuge is opened, internal droplets (aerosol) are discharged outside the centrifuge. In this way, infectious droplets (aerosol) may be released, so opening the centrifuge lid in the work space of the safety cabinet prevents the spread of infectious substances to the outside. Yes.

  A structure in which a centrifuge according to the prior art is incorporated in a safety cabinet is shown in Patent Document 1 (Japanese Patent Laid-Open No. 2007-111596). The centrifugal separation tank of the centrifuge is arranged on the downstream side (lower surface) of the work space, and as described in the embodiment, the airflow entering from the vent hole under the shutter is below the centrifuge formed on the work table lower surface. It flows so as to surround the separation tank and is led to the return duct.

  With this configuration, clean air in the work space above the centrifuge is maintained, and the work space and the outside of the safety cabinet are isolated by an air barrier formed by a vent hole under the shutter. The airflow for the air barrier passes through the lower part of the centrifuge formed on the lower surface of the work space and is guided to the return duct.

JP 2007-111596 A

  Japanese Patent Application Laid-Open No. 2007-111596 discloses a safety cabinet incorporating the above-described conventional centrifugal separator.

  A lid is formed on the work table surface that is the lower surface of the clean space that is the work space, and a separation tank of the centrifuge is formed below the cover. The airflow that has come down from the work space is sucked from three places: a vent hole in the work space, a space between the work table surface and the centrifuge separation tank, and a vent hole under the shutter and led to the return duct. The airflow sucked from the vent hole under the shutter passes through the return duct below the separation tank of the centrifuge and is guided to the blower. With this configuration, the work space and the space outside the safety cabinet are physically separated by the airflow under the shutter while maintaining the cleanliness that is the clean airflow in the work space.

  In a safety cabinet incorporating a centrifuge according to the prior art, the air flow sucked from the lower part of the shutter passes through the lower part of the centrifuge and is guided to the return duct. The state of the inhaled airflow may change.

  In addition, when it is desired to introduce a centrifugal separator having a large capacity, it may not be possible to secure a space for the airflow drawn from below the shutter.

  In the case of a safety cabinet, as described in the Japanese Industrial Standard JIS K3800 Biohazard Class II cabinet, when the airflow state changes, it is necessary to evaluate the physical isolation performance using Bacillus subtilis spores again.

  An object of the present invention is to provide a safety cabinet in which the position and size of a device incorporated in a work space are not affected by the state of airflow that determines the basic performance of the safety cabinet.

  Further, when the apparatus is incorporated in the work space, the safety cabinet tends to increase in size. When the safety cabinet is enlarged, the safety cabinet may not be brought into the installation location.

  Another object of the present invention is to provide a safety cabinet that can be carried in even if the carry-in path to the installation place is narrow relative to the safety cabinet.

  In order to achieve the above object, the present invention provides a supply system for supplying clean air to the work space through the first air cleaning means by the blowing means, a front shutter formed on the front surface of the work space, and a lower part of the front shutter. A work opening connected to the work space; an exhaust system for sucking air from the work opening and exhausting the air out of the safety cabinet through the second air cleaning means; and the first and second air cleaning means In the safety cabinet having a pressure chamber connected to the air blowing means, an air suction port is provided below the work opening, and a flow path for sending air sucked from the air suction port to the air blowing means is provided in the work space. It connected to the flow path installed in the side wall surface of this.

  Further, in the above safety cabinet, the space having the air suction port provided below the work opening is configured such that the central portion is shallow in the vertical direction and gradually becomes deeper as it goes to both sides. .

  The safety cabinet is characterized in that a fan is provided near the center of a space having an air inlet provided below the work opening.

  The safety cabinet is provided on a fan case having a blower, an exhaust HEPA filter, an intake HEPA filter, and a pressure chamber, a side circulation passage case provided on the right and left sides of the work space, and a back wall of the work space. A rear circulation flow path case, a suction grill case for sucking air installed below the work opening, and a leg case for supporting the safety cabinet body, each connecting case is provided with a connecting surface, The component case is assembled and used.

  Further, in the above-described safety cabinet, the case connected to the wall surface of the work space has a connecting portion, and the connecting portion is configured by a portion that becomes a negative pressure when the safety cabinet is used.

  According to the present invention, when a device such as an analyzer or an observation device is installed in a work space of a safety cabinet and arranged or fixed, the wind speed of the suction airflow (inflow airflow) formed in the work opening, In addition, it is possible to provide a safety cabinet in which the airflow state is not affected by the position and size of the apparatus.

  Further, in a safety cabinet where it is important that infectious materials do not leak out, it is possible to provide a safety cabinet that can be delivered in a divided state and assembled at the installation site.

1 is a structural cross-sectional view of a safety cabinet in which a device such as an analyzer according to a first embodiment of the present invention is incorporated. The structure sectional drawing and front view of the safety cabinet which incorporated apparatuses, such as the analyzer which shows 1st Embodiment of this invention, are shown. It is a front view of the safety cabinet incorporating apparatuses, such as an analyzer, showing a 1st embodiment of the present invention. It is the structure sectional drawing and front view of the safety cabinet which incorporated apparatuses, such as an analyzer, which shows a 2nd embodiment of the present invention. It is the structure sectional drawing of the safety cabinet incorporating apparatuses, such as an analyzer which shows a 3rd embodiment of the present invention, and a front view. Sectional drawing at the time of decomposition | disassembly of the structure of the safety cabinet incorporating apparatuses, such as an analyzer, which shows 4th Embodiment of this invention is shown. Sectional drawing of the structure at the time of the assembly of the safety cabinet incorporating apparatuses, such as an analyzer which shows 4th Embodiment of this invention is shown. It is a figure which shows the connection part of the safety cabinet incorporating apparatuses, such as an analyzer, which shows 4th Embodiment of this invention. It is a perspective view which shows the front lower part of the safety cabinet of this invention. It is the structure sectional drawing and front view of the safety cabinet which incorporated apparatuses, such as an analyzer, which shows a 5th embodiment of the present invention. It is a perspective view which shows the lower front part of the safety cabinet which shows 5th Embodiment of this invention. It is the structure sectional drawing and front view of a safety cabinet which incorporated apparatuses, such as an analyzer, showing a 6th embodiment of the present invention. It is a perspective view which shows the lower front part of the safety cabinet which shows 6th Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a side cross-sectional view and a front cross-sectional view of the structure of a safety cabinet in which a device such as an analyzer showing the first embodiment of the present invention is incorporated. FIG. 2 is a side sectional view and a front view of the structure of a safety cabinet in which a device such as an analyzer showing the first embodiment of the present invention is incorporated. Here, Fig.1 (a) has shown AA sectional drawing of FIG.1 (b).

  1 and 2, 1 is a safety cabinet, 2 is a work table surface on which work is performed, 3 is a work space, 4 is a front shutter that can be opened and closed vertically, 5 is a blower, and 6 is a work opening below the front shutter 4. Reference numeral 7 denotes an inflow air flow entering from outside the cabinet of the work opening 6, 8 denotes an exhaust port provided on the upper surface of the safety cabinet 1, and 9 denotes exhaust air exhausted from the exhaust port 8.

  10 is an infectious substance, 11 is a clear plate installed on the upper side of the work space 3, 12 a is an exhaust HEPA filter, 12 b is an intake HEPA filter, 13 is a pressure chamber 29 is positive, and 14 is a fan 5. It shows that the space is negative pressure. Further, 15 is a suction grill below the work opening 6, 16 is a flow path below the suction grill, 17 is blown air blown from the intake HEPA filter 12b, 18 is a leg of the safety cabinet 1, and 19 is a work space. Back side circulation channel installed on the back of the work space, 20 side circulation channels installed on the left and right of the work space, 22 return air flowing through the back circulation channel, 23 a back suction port of the work space 3, and 24a an analysis It is a device such as a measuring instrument or an observation instrument.

  Next, the configuration of the safety cabinet will be described.

  In FIG. 1 and FIG. 2, the safety cabinet is configured such that a rectifying plate 11 is disposed on the upper surface of the work space 3, and a work table surface 2 is formed on the lower surface of the work space 3. An air supply HEPA filter 12 b is disposed above the rectifying plate 11, and the air supply HEPA filter 12 b is connected to the pressure chamber 29. An exhaust HEPA filter 12 a and a blower 5 are also connected to the pressure chamber 29. By operating the blower 5, the pressure chamber 29 has a positive pressure 13, pressurizes the exhaust HEPA filter 12 a and the air supply HEPA filter 12 b, and each filter filters dust and allows clean air to flow. .

  A front shutter 4 is disposed in front of the work space 3, and a work opening 6 is formed below the front shutter 4. An operator (not shown) looks inside the work space 3 from the front shutter 4. Then, an arm is inserted into the work space 3 from the work opening 6, the infectious substance 10 is handled, and an experiment is performed.

  The structure of the air flow is that a suction grill 15 is formed on the lower surface of the work opening 6 of the front shutter 4, and the air outside the safety cabinet and a part of the air in the work space 3 are sucked from the suction grill 15 together. An air flow 7 is formed. The air sucked from the suction grille 15 passes through the suction grille lower flow path 16, is divided into left and right, passes through the side circulation flow path 20 connected to the left and right work space side surfaces 3 a, and is negative in which the blower 5 is disposed. The pressure is led to 14 parts. When the infectious substance 10 in the work space 3 is about to go out of the apparatus by the inflow air flow 7, it is sucked into the suction grill 15 and the work space 3 and the outside of the safety cabinet 1 can be shut off.

  The airflow sucked into the blower 5 includes external air dust and infectious substances 10. The air blown out from the blower 5 enters the pressure chamber 29 and pressurizes the exhaust HEPA filter 12a and the air supply HEPA filter 12b. The same amount of air that enters through the work opening 6 passes through the exhaust port 8 from the exhaust HEPA filter 12a, is exhausted as exhaust air 9 outside the safety cabinet 1, and the amount of air remaining in the total air volume of the blower 5 is The air supply HEPA filter 12 b passes through the rectifying plate 11 and is supplied to the work space 3 as blown air 17. The air supplied to the work space 3 is clean air because it is filtered by the air supply HEPA filter 12b. The air in the work space 3 is sucked into the suction grille 15 from the front of the work opening 6, and the other passes through the periphery of the device 24 a and is sucked into the rear suction port 23 on the rear surface of the work space 3 to return air 22. It passes through the circulation channel 19 and is sucked into the blower 5.

  The above is the flow of the airflow in the safety cabinet 1. The rectifying plate 11 disposed downstream of the air supply HEPA filter 12b is disposed for the purpose of equalizing the wind speed of the blown air 17 supplied to the work space 3.

  A work table surface 2 is formed on the lowermost surface of the work space 3, and legs 18 are formed below the work table surface 2 to support the main body of the safety cabinet 1.

  On the work table surface 2, an apparatus 24a is arranged. As shown in the configuration of the airflow, the inflow airflow 7 is not affected by the position of the device 24a in the work space 3, and if the device 24a is large enough to enter the work space 3, the flow of the device 24a The magnitude is also independent of the wind speed of the incoming airflow 7. If the device 24a is at a low position in the height direction for work, a treatment such as placing a table between the device 24a and the work table surface 2 is possible (not shown).

  FIG. 3 is a front view of a safety cabinet in which a device such as an analyzer according to the first embodiment of the present invention is incorporated.

  In the conventional safety cabinet 1, since the inflow air flow 7 sucked from the work opening 6 is sucked as a circulation flow path below the work table surface 2, it has a relatively uniform wind speed distribution in the left-right direction of the work opening 6. ing. On the other hand, in the present invention, since the circulation channel is not provided below the work table surface and is sucked from the side circulation channel 20 into the work opening 6 from the left and right directions, the size of the suction grille lower channel 16 is increased. Depending on the depth, there is a possibility that the wind speed of the inflowing air flow 7 is faster nearer to the side circulation channel 20 and slower toward the side circulation channel 20. In order to eliminate the wind speed distribution, in FIG. 3, the suction grille lower flow path 16 is inclined.

  Since only the airflow in the vicinity of the center of the work opening 6 is sucked into the suction grille lower flow path 16 near the center of the work opening 6, the air volume in the flow path is small 25a. In addition to the airflow sucked from the suction grill 15 directly above the flow path, the suction grill lower flow path 16 close to the side circulation path 20 is sucked in the vicinity of the center of the work opening 6, and the side circulation path 20 There is also a stream of air flowing through. Accordingly, the amount of air flowing through the suction grille lower flow path 16 is the smallest near the center of the work opening 6 and increases as it approaches the side circulation channels 20 on both sides (25b). In FIG. 3, in accordance with the increasing air volume, the distribution of the depth of the suction grille lower flow path 16 is made uniform, the force sucked from the work opening 6 is made uniform, and the inflow airflow 7 wind speed distribution is improved. Yes. That is, the suction grille lower flow path 16 is configured so that it is shallow in the vertical direction near the center and gradually becomes deeper toward both sides.

  In FIG. 3, the distribution of the depth of the suction grille lower flow path 16 is distributed, but the depth of the suction grille lower flow path 16 and the cross-sectional area of the method in which the airflow flows to the side circulation flow path are large. When it is possible to slow down the wind speed flowing through the flow path 16, it is possible to improve the wind speed distribution of the incoming airflow 7 even if the distribution is desired.

  Next, a case where an apparatus such as an analyzer is enlarged will be described.

  FIG. 4 is a structural sectional view and a front view of a safety cabinet incorporating a device such as an analyzer showing the second embodiment of the present invention.

  In FIG. 4, in the same manner as in the first embodiment, the airflow sucked from the suction grille 15 passes through the side circulation channel 20 and is sucked into the blower 5. Although the leg 18 is abolished and the work table surface 2 is configured below, the case size of the portion through which the airflow flows can be manufactured with the same dimensions as in the first embodiment.

  With this configuration, a large apparatus 24b larger than that of the first embodiment can be arranged in the work space 3. Although the sizes of the devices 24a and 24b are different, the air flow structure including the inflow air flow 7 is exactly the same, the air flow outside the work space 3 and the safety cabinet 1 is blocked, and the infectious substance 10 in the work space 3 is external. Never leak out.

  The work table surface 2 may be a floor surface on which the safety cabinet 1 is placed without being configured as a part of the main body case 1a of the safety cabinet 1.

  Next, another embodiment of the suction grill lower passage 16 will be described.

  FIG. 5 is a structural sectional view and a front view of a safety cabinet incorporating a device such as an analyzer showing the third embodiment of the present invention.

  In FIG. 5, the structure of the air flow is that a suction grill 15 is formed on the lower surface of the work opening 6 of the front shutter 4, and air outside the apparatus and part of the air in the work space 3 are sucked together from the suction grill 15. Inflow airflow 7 is formed. The air sucked from the suction grille 15 passes through the suction grille lower channel 16, passes through the side circulation channel 20 connected to one side of the work space side surface 3 a, and reaches the negative pressure 14 part where the blower 5 is arranged. Led. When the infectious substance 10 in the work space 3 is about to go out of the safety cabinet 1 due to the inflow airflow 7, it is sucked into the suction grille 15 and the work space 3 and the safety cabinet 1 can be shut off.

  Since the airflow after blowing out from the blower 5 has the same configuration as that of the first embodiment, the description thereof is omitted.

  In order to make the wind speed at which the inflow air flow 7 is sucked uniform in the left-right direction of the work opening 6, the suction force sucked from the suction grill 15 needs to be made uniform in the left-right direction of the work opening 6. Therefore, the depth of the suction grille lower flow path 16 is made deeper near the side circulation flow path 20 and deeper from the side circulation flow path 20, that is, shallower near the center, and flows to each cross section of the suction grill lower flow path 16. The depth of the suction grille lower passage 16 is inclined according to the air volume.

  In this configuration, when the space of the side circulation channel 20 on one side of the safety cabinet 1 cannot be taken, or as shown in FIG. This is effective when the door 31 is provided and the large-sized device 24 b is taken in and out from the side surface of the work space 3.

  In FIG. 5, a slight width is given to the side wall on the left side, but this is the side wall.

  Next, a case where the safety cabinet becomes large and cannot be carried into a laboratory or the like to be used will be described.

  FIG. 6 is a diagram showing a structure at the time of disassembling of a safety cabinet in which a device such as an analyzer showing the fourth embodiment of the present invention is incorporated.

  When the device 24 such as an analyzer disposed in the work space 3 is enlarged, naturally, the safety cabinet 1 in which the device 24 is incorporated is also enlarged. When the safety cabinet 1 is enlarged, there is a possibility that it cannot be carried into the laboratory to be used. Therefore, it is also effective to make the safety cabinet 1 disassembleable.

The safety cabinet 1 includes a fan case 26, a side circulation passage case 20a, a rear circulation passage case 19a, a suction grill case 15a, and a leg case 18a.
6A is a side sectional view of the structure of the safety cabinet, and FIG. 6B is a front sectional view.
6 (a) and 6 (b), the safety cabinet 1 includes a fan case 26, a side circulation channel case 20a, a rear circulation channel case 19a, a suction grill case 15a,
It is comprised from the leg part case 18a. Each component includes a connecting surface 27. The fan case 26 includes the blower 5, the exhaust HEPA filter 12 a, the air supply HEPA filter 12 b, and the pressure chamber 29 that are the most important in the safety cabinet 1. Since the connecting surface of the pressure chamber 29 and the pressure chamber 29 of each HEPA filter does not need to be divided at the time of carrying in, etc., leakage from the HEPA filter portion, leakage from the positive pressure 13 portion of the pressure chamber 29, etc. The factor is eliminated.

  FIG. 7 shows a cross-sectional view of a structure in which the cases of the safety cabinet disassembled in FIG. 6 are assembled.

  In FIG. 7, the elements of the fan case 26, the side circulation passage case 20 a, the rear circulation passage case 19 a, the suction grill case 15 a, and the leg case 18 a are connected by a connection surface 27. The connection surface is connected at a portion that becomes the negative pressure 14 when the blower 5 is operated. This can be realized by integrating the pressure chamber 29 in the fan case 26.

  By configuring the connecting surface with 14 parts of negative pressure, the air current containing the infectious substance 10 does not leak from the negative pressure 14 part during the operation of the safety cabinet 1, and therefore it is possible to prevent the infectious substance 10 from leaking. Become.

  Next, the connection surface of the safety cabinet which is 4th Embodiment of this invention is demonstrated.

  FIG. 8A is a side cross-sectional view of the safety cabinet of the fourth embodiment, and FIG. 8B shows a connection surface of each case of the safety cabinet.

  In FIG. 8A, as described above, the connecting surfaces of the elements of the fan case 26, the side circulation passage case 20a, the rear circulation passage case 19a, the suction grill case 15a, and the leg case 18a are connected with bolts and nuts 32. Link. The portion where the connecting portion is inside the safety cabinet 1 is provided with a cover 28 on the side circulation passage case 20a, the rear circulation passage case 19a, and the like. The connection is possible by fastening at 32 and then closing with the cover 28. The connecting surface 27 is a negative pressure portion, but the connecting surface 27 may be coked with a caulking material to improve the sealing performance.

  FIG. 9 is a perspective view showing a suction grill below the front shutter 4 of the safety cabinet 1.

  In FIG. 9, the front shutter 4 and the work opening 6 of the suction grill 15 are provided, and the suction grill 15 has a mesh structure so that air can be sucked easily. The air flowing into the suction grille 15 is the air outside the safety cabinet and the air inside the work space 3, and since the inflow airflow 7 exists in the suction grille 15, the air flowing out from the work space 3 to the outside of the safety cabinet is Absent.

  Further, the air volume sucked into the suction grill 15 is not uniform, the air volume near the center of the suction grill 15 is small, and the air volume gradually increases toward both sides.

  In the present invention, as the air volume sucked into the suction grille 15 is made uniform, the structure below the suction grille 15 is made shallower in the vicinity of the center in the vertical direction in the suction grille lower flow path 16 and goes to both sides. Configure to be deeper. That is, it becomes a structure which forms the slope which a center part becomes a vertex and falls on both sides, respectively.

With such a configuration, as described with reference to FIG. 3, the suction grille lower flow path 16 has a small air volume 25 a near the center and air volume tables 25 b on both sides, and the inflow air flow 7 is made uniform.
The air in the suction grill lower channel 16 is communicated with and sent to the side circulation channels 20 installed on both side surfaces of the work space 3 of the safety cabinet 1.

  Next, a fifth embodiment of the present invention is shown in FIGS.

  10 and 11 are different from FIGS. 1 and 2 of the first embodiment of the present invention in that a fan 33 is provided near the center of the suction grill lower flow path 16 below the work opening 6 of the safety cabinet 1. It is installed.

  In the figure, as shown in FIG. 10B, two fans 33 are installed at positions slightly apart from the center in the suction grille lower flow path 16 of the safety cabinet 1.

  The fan 33 is operated when the inflow airflow 7 flowing from the work opening 6 is small, increases the amount of air sucked from the suction grille 15, and increases the inflow airflow 7. A propeller fan or the like is used as a fan.

  Next, a configuration in which a fan is installed will be described.

In the configuration of the safety cabinet 1 in FIG. 12A, a clear plate 11 is disposed on the upper surface of the work space 3, and a work table surface 2 is formed on the lower surface. An air supply HEPA filter 12b is disposed above the rectifying plate 11, and the air supply HEPA filter 12b is connected to a pressure chamber.
An exhaust HEPA filter 12a and a blower 5 are connected to the pressure chamber. By operating the blower 5, the pressure chamber becomes a positive pressure, pressurizing the exhaust HEPA filter 12 a and the supply HEPA filter 12 b, and each filter filters dust to generate clean air. A front shutter 4 is disposed in front of the work space 3, a work opening 6 is formed below the front shutter 4, and the operator looks inside the work space 4 from the front shutter 4 and An experiment is conducted by inserting a hand into the working space, handling the infectious substance 10 and the like.

  Next, the airflow of the safety cabinet 1 will be described.

The structure of the air flow is that a suction grill 15 is formed on the lower surface of the work opening 6 of the front shutter 4, and the air outside the safety cabinet 1 and a part of the air in the work space are sucked together from the suction grill 15, 7 is formed.
The air sucked from the suction grille 15 passes through the suction grille lower flow path 16, is divided into left and right, and the negative pressure in which the blower 5 is arranged via the side circulation flow path 20 connected to the side surfaces of the left and right work spaces. Led to the department.

  When the infectious substance 10 in the work space 3 tries to go out of the safety cabinet 1 by the inflow airflow 7, it is sucked into the suction grille 15 and the work space 3 and the safety cabinet 1 are blocked.

The airflow sucked into the blower 5 includes external air dust and infectious substances 10.
The air blown out from the blower 5 enters the pressure chamber and pressurizes the exhaust HEPA filter and the intake HEPA filter. The same amount of air that enters through the work opening 6 is exhausted from the exhaust HEPA filter through the exhaust port 8 to the outside of the safety cabinet 1, and the remaining air amount of the blower 5 is rectified from the supply HEPA filter. It passes through the plate 11 and is supplied into the work space 3 as blown air 17.
The air supplied to the work space 3 is clean air because it is filtered by the air supply HEPA filter 12b.
The air in the work space 3 is sucked into the suction grill 15 from the near side, and the other passes around the device 24 such as an analyzer, and is sucked into the back suction port 23 of the work space 3 to become the return air 22. It passes through 19 and is sucked into the blower 5.

  The above is description of the flow of the airflow in the safety cabinet 1.

In FIG. 12B, in Example 6, the air sucked from the suction grill 15 below the work opening 6 is a side circulation channel installed on the side surface of the work space 3 via the suction grill lower channel 16. 20 connected to the blower 5 side.
Further, the air volume sucked into the suction grill 5 is larger on both sides near the side circulation channel 20 because the side circulation channel 20 is on both sides than near the center.
In the sixth embodiment, a fan 33 is provided near the center in order to make the air volume sucked from the suction grill 5 uniform.

  FIG. 13 is a partial perspective view showing a portion of the suction grille lower flow path 16 on the front surface of the safety cabinet 1.

In FIG. 13, the suction grill 15 below the work opening 6 is formed of a mesh having a low air resistance. Moreover, the both sides of the suction grille lower flow path 16 which is the space part of the sucked air have openings connected to the side circulation flow path 20.
Further, a fan 33 is installed near the center of the side circulation passage 20 in order to make the intake air from the intake grill 15 uniform. With such a configuration, a uniform air volume can be sucked.

DESCRIPTION OF SYMBOLS 1 ... Safety cabinet 1a Main body case 2 Work surface 3 Work space 3a Work space side 4 Front shutter 5 Blower 6 Work opening 7 Inflow air flow 8 Exhaust port 9 Exhaust air 10 Infectious substance 11 ··· Rectification plate 12a · HEPA filter for exhaust 12b · HEPA filter for air supply 13 · Positive pressure 14 · Negative pressure 15 · Suction grill 15a · Suction grill case 16 · Suction grill lower passage 17 · Blowing air 18 · Leg 18a · · · Leg case 19... Backside circulation channel 19 a. Backside circulation channel case 20. Side circulation channel 20 a. Side circulation channel case 21. ······································· 25b ············ 25b ·························································································································································· Location loading and unloading opening 31 ‥ equipment loading and unloading opening door 32 ‥ bolts and nuts 33 ‥ fan

Claims (5)

A supply system for supplying clean air to the work space through the first air cleaning means by the blowing means;
A front shutter formed in front of the work space;
A work opening connected to the work space under the front shutter;
An exhaust system for sucking air from the working opening and exhausting the air out of the safety cabinet via the second air cleaning means;
In a safety cabinet having a pressure chamber connected to the first and second air cleaning means and the air blowing means,
An air suction port is provided below the work opening, and a flow path for sending air sucked from the air suction port to the blowing means is connected to a flow path installed on a side wall surface of the work space. Safety cabinet to do. The safety cabinet of claim 1,
The safety cabinet according to claim 1, wherein a space having an air suction port provided below the work opening is configured such that a central portion is shallow in a vertical direction and gradually increases toward both sides. The safety cabinet of claim 1,
A safety cabinet, wherein a fan is provided near the center of a space having an air suction port provided below the work opening. The safety cabinet is provided on a fan case having a blower, an exhaust HEPA filter, an intake HEPA filter, and a pressure chamber, a side circulation passage case provided on the right and left sides of the work space, and a back wall of the work space. A rear circulation flow path case, a suction grill case for sucking air installed below the work opening, and a leg case for supporting the safety cabinet body,
A safety cabinet characterized in that each configuration case is provided with a connecting surface, and the configuration case is assembled and used. The safety cabinet according to claim 4,
The case connected to the wall surface of the work space has a connecting part,
A safety cabinet characterized in that the connecting portion is composed of a portion that becomes negative pressure when the safety cabinet is used.

Images