CN219072980U - B2 type biosafety cabinet - Google Patents

Abstract

The utility model provides a B2 type biosafety cabinet, which comprises a cabinet body, wherein an operation cavity is arranged on the cabinet body, an air inlet and a first air outlet are arranged at the top of the cabinet body, a first air exhaust channel which is positioned at the rear side of the operation cavity and communicated with the first air outlet is arranged in the cabinet body, and a first sealing valve is arranged between the upper opening of the first air exhaust channel and the first air outlet; the cabinet body is also internally provided with a second exhaust channel positioned at the side part of the operation cavity, a second closed valve is arranged between the upper opening of the second exhaust channel and the first exhaust opening, and the side wall of the cabinet body is provided with a second exhaust opening communicated with the second exhaust channel; when the first sealing valve is in an open state, the second sealing valve is in a closed state; when the first sealing valve is in a closed state, the second sealing valve is in an open state. The B2 type biosafety cabinet can realize the switching of the exhaust channel, prevent the positive pressure environment from being formed in a laboratory when the B2 type biosafety cabinet is closed, and achieve the effect of precisely controlling the pressure difference fluctuation in the laboratory.

Description

B2 type biosafety cabinet

Technical Field

The utility model belongs to the technical field of laboratory equipment, and particularly relates to a B2 type biosafety cabinet.

Background

The biosafety cabinet is used for protecting operators themselves, laboratory environments and equipment of experimental materials when the biosafety cabinet is used for operating primary cultures, bacterial strains, diagnostic specimens and other experimental materials with infectivity, and can effectively avoid laboratory infection and cross contamination of cultures caused by aerosol exposure. The B2 type biosafety cabinet is the most widely used cabinet type at present, and the working principle is that the equipment sucks air in a laboratory from the top through a built-in blower, the sucked air is filtered by a HEPA filtering unit, the filtered air is blown onto an operation surface in the cabinet body, meanwhile, the equipment sucks the air through a safe cabinet door opened on the operation surface, the two air are converged in an independent exhaust channel arranged at the rear of the equipment, and finally the air is discharged out of the laboratory after reaching the standard through safety treatment.

However, in the practical use process of the B2 type biosafety cabinet, the direct-current type fresh air treatment mode is adopted, so that the air exhaust quantity is relatively large (1500-2200 m ³ H) and the inhaled air comes from the laboratory interior, the opening and closing process of which causes great pressure fluctuation in the laboratory interior, the pressure difference in the laboratory is difficult to control, and the risk of high positive pressure value in the laboratory is easily caused especially when the equipment is closed. To solve the above problems, in the prior art, a mode of adding a control device to an exhaust system of a laboratory is mostly adopted, but many laboratories have the problems of tense process layout, difficult arrangement of exhaust louvers or channels, and the like, and the problems are difficult to solve by the laboratory exhaust system.

Disclosure of Invention

The embodiment of the utility model provides a B2 type biosafety cabinet, which can reduce the positive air pressure value in a laboratory through the arrangement of a second air exhaust channel, effectively control the pressure difference fluctuation in the laboratory and avoid the defect that an air exhaust system cannot be arranged due to the influence of the spatial layout of the laboratory.

In order to achieve the above purpose, the utility model adopts the following technical scheme: the B2 type biosafety cabinet comprises a cabinet body, wherein an operation cavity with a forward opening is arranged on the cabinet body, a cabinet door for opening or closing the operation cavity is connected to the cabinet body in a sliding manner, and an air inlet and a first air outlet which are respectively arranged close to two sides of the cabinet body are arranged at the top of the cabinet body; the cabinet body is internally provided with an air supply channel which is positioned above the operation cavity and is used for communicating the air inlet with the operation cavity, an air feeder which is arranged close to the air inlet is arranged in the air supply channel, a horizontally extending air supply filter is arranged between the air supply channel and the operation cavity, a first air exhaust channel which is positioned at the rear side of the operation cavity and is communicated with a first air outlet is arranged in the cabinet body, a first filter which is positioned below the first air outlet and horizontally extends is arranged at the upper part of the first air exhaust channel, and a first sealing valve is arranged between the upper opening of the first air exhaust channel and the first air outlet;

the cabinet body is also internally provided with a second exhaust channel which is positioned at the side part of the operation cavity and communicated with the first exhaust outlet to exhaust the air in the laboratory to the outside of the laboratory, the second exhaust channel is positioned at one side close to the first exhaust outlet, a second closed valve is arranged between the upper opening of the second exhaust channel and the first exhaust outlet, and the side wall of the cabinet body is provided with a second exhaust outlet communicated with the second exhaust channel;

when the first sealing valve is in an open state, the second sealing valve is in a closed state; when the first sealing valve is in a closed state, the second sealing valve is in an open state.

As another embodiment of the utility model, an exhaust filter corresponding to the second exhaust outlet is arranged in the cabinet body, and the exhaust filter adopts a high-efficiency filter.

As another embodiment of the utility model, the first exhaust channel is connected with the first exhaust outlet through a first bent connector, the first sealing valve is arranged between the first exhaust channel and the first bent connector, the second exhaust channel is connected with the first exhaust outlet through a second bent connector, the second sealing valve is arranged between the second exhaust channel and the second bent connector, the first exhaust outlet is provided with a three-way connector, the first bent connector and the second bent connector are respectively connected with two opposite ends of the three-way connector, and the first exhaust outlet is connected with the third end of the three-way connector.

As another embodiment of the utility model, the B2 type biosafety cabinet further comprises a PLC controller, wherein the PLC controller is respectively and electrically connected with the first sealing valve and the second sealing valve, a control panel electrically connected with the PLC controller is embedded on the front side wall of the cabinet body, and the control panel is positioned above the operation cavity.

As another embodiment of the utility model, exhaust holes communicated with the first exhaust channel are respectively arranged on the two side cavity walls and the rear side cavity wall of the operation cavity, and the exhaust holes are arranged at the lower part of the operation cavity.

As another embodiment of the utility model, a sterilizing component and a leak detection component which are arranged corresponding to the first filter are respectively arranged above the first exhaust channel, the sterilizing component is used for sterilizing the first filter in situ, the leak detection component is used for detecting the first filter in situ, and the sterilizing component and the leak detection component are respectively electrically connected with the PLC.

As another embodiment of the present utility model, the sterilization assembly includes a steam spraying element and a sterilization detection element which are disposed at intervals along the extension direction of the first filter, the steam spraying element being capable of releasing VHP steam to sterilize the first filter, the sterilization detection element being capable of monitoring an effect parameter of the first filter and transmitting the effect parameter to the PLC controller.

As another embodiment of the utility model, the leak detection assembly includes a smoker disposed on one side of the first filter, a scanning element disposed above the first filter for scanning the first filter line by line, and a sampling element disposed above the first filter and coupled to the scanning element.

As another embodiment of the utility model, the air supply filter, the air exhaust filter and the first filter are respectively provided with a differential pressure meter for monitoring differential pressure parameters, and the differential pressure meters are electrically connected with the PLC and used for sending the differential pressure parameters to the PLC.

As another embodiment of the utility model, the front side wall of the cabinet body is hinged with an access door communicated with the second exhaust channel, and the access door corresponds to the exhaust filter in front and back.

The B2 type biosafety cabinet provided by the utility model has the beneficial effects that: compared with the prior art, through setting up the passageway of airing exhaust of second, with the surplus amount of wind in the laboratory outside through second air exit and first air exit, avoid forming the malleation environment in the laboratory. When the B2 type biosafety cabinet is in an open state, the first sealing valve is in an open state, the second sealing valve is in a closed state, the air in the laboratory is sucked into the cabinet body through the air inlet by the air feeder, is fed into the operation cavity through the air feeding filter and is then discharged into the first air exhaust channel, meanwhile, the air entering from the cabinet door is also discharged into the first air exhaust channel, two air flows are converged to be filtered by the air exhaust filtering section, and then are discharged out of the room from the first air exhaust outlet through the first sealing valve; when the B2 type biosafety cabinet is in a closed state, the cabinet door is closed, the blower stops running, the first sealing valve is closed, and the second sealing valve is opened, at the moment, air in the laboratory enters the second exhaust channel from the second exhaust outlet and is discharged outdoors from the first exhaust outlet through the second sealing valve. According to the B2 type biosafety cabinet provided by the utility model, on the basis of setting the second exhaust channel, the switching mode of the opening and closing states of the first sealing valve and the second sealing valve is adopted to realize the switching of the exhaust channels, so that the positive pressure environment is prevented from being formed in a laboratory when the B2 type biosafety cabinet is closed, the problem that the louver air ports with equivalent switching of exhaust cannot be installed due to tension of the spatial layout of the laboratory is avoided, and the effect of accurate control of pressure difference fluctuation in the laboratory can be achieved.

Drawings

FIG. 1 is a schematic side view of a B2-type biosafety cabinet according to an embodiment of the utility model;

FIG. 2 is a schematic view of a cross-section A-A of FIG. 1 according to an embodiment of the present utility model;

FIG. 3 is a schematic diagram of airflow patterns of a B2-type biosafety cabinet according to an embodiment of the utility model;

FIG. 4 is a schematic front view of the airflow pattern of FIG. 3 according to an embodiment of the present utility model;

fig. 5 is a schematic diagram of an application scenario of the B2-type biosafety cabinet provided in fig. 1 according to an embodiment of the utility model.

In the figure:

1. a cabinet body; 11. an air inlet; 12. a first exhaust outlet; 121. a three-way connection; 13. a first exhaust passage; 131. a first bent connector; 14. a second exhaust outlet; 15. a second exhaust passage; 151. a second bent connector; 16. an air supply channel; 17. an access door; 2. an operating chamber; 21. an exhaust hole; 3. a cabinet door; 4. a blower; 5. an air supply filter; 61. a first filter; 62. a sterilization assembly; 621. a steam ejection element; 622. a sterilization detection element; 63. a leak detection assembly; 631. a smoke generator; 632. a scanning element; 633. a sampling element; 7. a first sealing valve; 8. a second sealing valve; 9. an exhaust filter; 10. a laboratory; 20. a room air conditioning unit; 30. a system exhaust fan; 40. type B2 biological safety cabinet exhaust fan.

Detailed Description

In order to make the technical problems, technical schemes and beneficial effects to be solved more clear, the utility model is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the utility model.

It will be understood that when an element is referred to as being "disposed on" another element, it can be directly on the other element or be indirectly on the other element. It is to be understood that the terms "length," "width," "upper," "lower," "front," "rear," "top," "bottom," "inner," "outer," and the like indicate or are based on the orientation or positional relationship shown in the drawings, merely to facilitate describing the present utility model and simplify the description, and do not indicate or imply that the devices or elements being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus are not to be construed as limiting the present utility model. The terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present utility model, the meaning of "a plurality" or "a number" means two or more, unless specifically defined otherwise.

Referring to fig. 1 to 5, a B2-type biosafety cabinet according to the present utility model will now be described. The B2 type biosafety cabinet comprises a cabinet body 1, wherein an operation cavity 2 with a forward opening is arranged on the cabinet body 1, a cabinet door 3 for opening or closing the operation cavity 2 is connected to the cabinet body 1 in a sliding manner, and an air inlet 11 and a first air outlet 12 which are respectively arranged close to two sides of the cabinet body 1 are arranged at the top of the cabinet body 1; the cabinet body 1 is internally provided with an air supply channel 16 which is positioned above the operation cavity 2 and is used for communicating the air inlet 11 with the operation cavity 2, the air supply channel 16 is internally provided with a blower 4 which is arranged close to the air inlet 11, a horizontally extending air supply filter 5 is arranged between the air supply channel 16 and the operation cavity 2, the cabinet body 1 is internally provided with a first air exhaust channel 13 which is positioned at the rear side of the operation cavity 2 and is communicated with a first air exhaust opening 12, the upper part of the first air exhaust channel 13 is provided with a first filter 61 which is positioned below the first air exhaust opening 12 and horizontally extends, and a first sealing valve 7 is arranged between the upper opening of the first air exhaust channel 13 and the first air exhaust opening 12; the cabinet body 1 is also internally provided with a second exhaust channel 15 which is positioned at the side part of the operation cavity 2 and is communicated with the first exhaust outlet 12 to exhaust the air in the laboratory to the outside of the laboratory, the second exhaust channel 15 is positioned at one side close to the first exhaust outlet 12, a second closed valve 8 is arranged between the upper opening of the second exhaust channel 15 and the first exhaust outlet 12, and the side wall of the cabinet body 1 is provided with a second exhaust outlet 14 which is communicated with the second exhaust channel 15; when the first sealing valve 7 is in an open state, the second sealing valve 8 is in a closed state; when the first closing valve 7 is in the closed state, the second closing valve 8 is in the open state.

Compared with the prior art, the B2 type biosafety cabinet provided by the embodiment has the advantages that excessive air quantity in the laboratory 10 is discharged outdoors through the second air outlet 14 and the first air outlet 12 by arranging the second air outlet channel 15, so that a positive pressure environment is avoided in the laboratory 10. When the B2 type biosafety cabinet is in an open state, the first sealing valve 7 is in an open state, the second sealing valve 8 is in a closed state, the air in the laboratory 10 is sucked into the cabinet body 1 through the air inlet 11 by the air blower 4, is sent into the operation cavity 2 through the air supply filter 5 and is then discharged into the first air discharge channel 13, meanwhile, the air entering from the cabinet door 3 is also discharged into the first air discharge channel 13, and the two air flows are converged to be filtered by the air discharge filter section 6 and then discharged out of the room through the first air discharge port 12 by the first sealing valve 7; when the B2 type biosafety cabinet is in a closed state, the cabinet door 3 is closed, the blower 4 stops running, the first sealing valve 7 is closed, the second sealing valve 8 is opened, at this time, air in the laboratory 10 enters the second exhaust channel 15 from the second exhaust outlet 14 and is discharged outdoors from the first exhaust outlet 12 through the second sealing valve 8. The B2 type biosafety cabinet provided by the utility model realizes the switching of the exhaust channels by adopting the mode of switching the opening and closing states of the first closed valve 7 and the second closed valve 8 on the basis of arranging the second exhaust channel 15, prevents the positive pressure environment from being formed in the laboratory 10 when the B2 type biosafety cabinet is closed, avoids the problem that the louver air ports with the equivalent switching of exhaust cannot be installed due to the tension of the spatial layout of the laboratory 10, and can achieve the effect of precise control of pressure difference fluctuation in the laboratory 10.

In the embodiment, an air inlet 11 is arranged at one side of the top of a cabinet body 1, the air inlet 11 can meet the requirement of the air inlet speed of the B2 type biosafety cabinet, the air inlet speed is controlled to be 4-6 m/s, a blower 4 adopts a low-noise and high-static-pressure axial flow fan, the noise is not more than 50 decibels, the total pressure is not less than 350Pa, an air supply filter 5 adopts an efficient filter to efficiently filter air fed into an operation cavity 2, the air supply quantity meets the technical requirement of 0.36-0.54 m/s of the air inlet speed of the surface of the operation cavity 2, and the cabinet door 3 ensures the surface air speed to be 0.5m/s under the safety height of 200 mm. The air flow entering from the air inlet 11 and the air flow entering from the cabinet door 3 are converged in the first air exhaust channel 13, the air flow can be exhausted outside after being filtered, in order not to cause air flow disturbance, the first filter 61 needs to meet the requirement of the sum of the air volumes of the two air flows, specifically, the size of the first filter 61 needs to be calculated and determined according to the actual size of the B2 type biosafety cabinet, and a first sealing valve 7 is arranged between the first air exhaust channel 13 and the first air exhaust opening 12; the second exhaust channel 15 in the cabinet body 1 is independently arranged and is not communicated with the operation cavity 2, and when the B2 type biosafety cabinet is in a closed state, an outward exhaust channel is provided for the excess air quantity in the laboratory 10 so as to prevent positive pressure in the laboratory 10; the second exhaust channel 15 shares the first exhaust outlet 12 with the first exhaust channel 13 after passing through the second closed valve 8, and the switching of the opening and closing states between the first closed valve 7 and the second closed valve 8 can realize the switching of the two exhaust channels of the first exhaust channel 13 and the second exhaust channel 15, so as to realize the control of the fluctuation of the internal pressure difference of the laboratory 10; on the basis, the first sealing valve 7 and the second sealing valve 8 are provided with built-in sealing rubber strips, so that the requirement of tightness can be met.

As a specific implementation manner of the embodiment of the present utility model, referring to fig. 1, 2 and 5, an exhaust filter 9 corresponding to the second exhaust port 14 is disposed in the cabinet 1, and the exhaust filter 9 is a high-efficiency filter.

In this embodiment, when the B2 type biosafety cabinet is closed, the excessive air volume in the laboratory 10 needs to be discharged outside through the second air outlet 14, and in order to ensure no pollution discharge and pressure difference, the air discharge filter 9 is disposed at the second air outlet 14 and adopts rated air discharge volume as2000m ³ And (3) efficiently filtering the size of the tuyere.

As a specific implementation manner of the embodiment of the present utility model, referring to fig. 2, the first exhaust channel 13 is connected to the first exhaust port 12 through a first bent connector 131, the first sealing valve 7 is disposed between the first exhaust channel 13 and the first bent connector 131, the second exhaust channel 15 is connected to the first exhaust port 12 through a second bent connector 151, the second sealing valve 8 is disposed between the second exhaust channel 15 and the second bent connector 151, the first exhaust port 12 is provided with a three-way connector 121, the first bent connector 131 and the second bent connector 151 are respectively connected to opposite ends of the three-way connector 121, and the first exhaust port 12 is connected to a third end of the three-way connector 121.

In this embodiment, the first exhaust channel 13 is sequentially communicated with the first exhaust port 12 through the first sealing valve 7, the first bent connecting piece 131, the three-way connecting piece 121, and the second exhaust channel 15 is sequentially communicated with the first exhaust port 12 through the second sealing valve 8, the second bent connecting piece 151, the three-way connecting piece 121, and the second air outlet; the outer end of the first air outlet 12 is connected with a fixed air quantity valve, the air quantity control of the fixed air quantity valve does not need external power, and the position of the control valve is positioned by means of air flow force in the air pipe, so that the requirement of constant air supply quantity can be met. In the embodiment, the fixed air quantity valve adopts a Venturi valve or a butterfly valve.

As a specific implementation manner of the embodiment of the present utility model, referring to fig. 2, the B2 type biosafety cabinet further includes a PLC controller, the PLC controller is electrically connected to the first sealing valve 7 and the second sealing valve 8 respectively, a control panel electrically connected to the PLC controller is embedded on the front side wall of the cabinet body 1, and the control panel is located above the operation cavity 2.

In this embodiment, the first sealing valve 7 and the second sealing valve 8 are both quick electric actuators, and the response time of the actuators is not longer than 3s, so as to realize quick switching of the air duct, and the PLC controller can meet the control requirements of interlocking control of the first sealing valve 7 and the second sealing valve 8, monitoring of the opening height and the surface wind speed of the cabinet door 3, and the like.

As a specific implementation manner of the embodiment of the present utility model, referring to fig. 2 and 4, exhaust holes 21 communicated with the first exhaust channel 13 are respectively formed on two side walls and a rear side wall of the operation cavity 2, and the exhaust holes 21 are uniformly arranged at the lower part of the operation cavity 2 so as to meet the requirements of exhaust wind speed and wind volume.

As a specific implementation manner of the embodiment of the present utility model, referring to fig. 1 and 2, a disinfection assembly 62 and a leak detection assembly 63, which are disposed corresponding to the first filter 61, are further disposed above the first exhaust channel 13, the disinfection assembly 62 is used for in-situ disinfecting the first filter 61, the leak detection assembly 63 is used for in-situ leak detecting the first filter 61, and the disinfection assembly 62 and the leak detection assembly 63 are electrically connected with the PLC controller, respectively. The first filter 61 is sterilized in situ and leak-detected in situ to ensure high quality filtration of the air before it is discharged outside the room, avoiding contamination of the outdoor environment.

As a specific implementation of the embodiment of the present utility model, referring to fig. 2, the sterilization assembly 62 includes a steam spraying element 621 and a sterilization detecting element 622 that are disposed at intervals along the extending direction of the first filter 61, where the steam spraying element 621 can release VHP steam to sterilize the first filter 61, and the sterilization detecting element 622 can monitor an effect parameter of the first filter 61 and send the effect parameter to the PLC controller.

In this embodiment, the steam spraying element 621 is externally connected with a VHP generator to release VHP steam to sterilize the first filter 61, and the sterilization detecting element 622 samples and analyzes the VHP sterilization effect and sends the effect parameters obtained by analysis to the PLC controller to ensure the sterilization quality.

As an embodiment of the present utility model, referring to fig. 1 and 2 together, the leak detection assembly 63 includes a smoke generator 631 disposed on one side of the first filter 61, a scanning element 632 disposed above the first filter 61 for scanning the first filter 61 line by line, and a sampling element 633 disposed above the first filter 61 and connected to the scanning element 632.

In this embodiment, the smoke generator 631 performs upstream smoke generation, samples and analyzes the smoke generation concentration to detect whether the smoke generation concentration reaches the standard, the scanning element 632 is configured with a "snake-shaped" automatic scanning leak detection mechanism, performs in-situ leak detection scanning on the first filter 61, and finally performs leak detection analysis by externally connecting the sampling element 633 with a dust particle counter.

As a specific implementation manner of the embodiment of the present utility model, the air supply filter 5, the air exhaust filter 9 and the first filter 61 are respectively provided with a differential pressure meter for monitoring differential pressure parameters, the differential pressure meter is electrically connected with the PLC controller and is used for sending the differential pressure parameters to the PLC controller, and an alarm is arranged in the PLC controller, and when the differential pressure meter monitors that the differential pressure parameters of each filter reach the final resistance, the alarm gives an alarm.

As a specific implementation manner of the embodiment of the present utility model, referring to fig. 2, an access door 17 is hinged on the front side wall of the cabinet body 1 and is communicated with the second exhaust channel 15, the access door 17 corresponds to the exhaust filter 9 in front and back, and the exhaust filter 9 can be manually scanned and detected by opening the access door 17, so that the present utility model has good practicability.

The foregoing description of the preferred embodiments of the utility model is not intended to be limiting, but rather is intended to cover all modifications, equivalents, and alternatives falling within the spirit and principles of the utility model.

Claims (10)

1. The B2 type biosafety cabinet is characterized by comprising a cabinet body, wherein an operation cavity with a forward opening is arranged on the cabinet body, a cabinet door for opening or closing the operation cavity is connected to the cabinet body in a sliding manner, and an air inlet and a first air outlet which are respectively arranged close to two sides of the cabinet body are arranged at the top of the cabinet body; the cabinet body is internally provided with an air supply channel which is positioned above the operation cavity and is used for communicating the air inlet with the operation cavity, an air feeder which is arranged close to the air inlet is arranged in the air supply channel, a horizontally extending air supply filter is arranged between the air supply channel and the operation cavity, the cabinet body is internally provided with a first air exhaust channel which is positioned at the rear side of the operation cavity and is communicated with the first air exhaust opening, the upper part of the first air exhaust channel is provided with a first filter which is positioned below the first air exhaust opening and horizontally extends, and a first sealing valve is arranged between the upper opening of the first air exhaust channel and the first air exhaust opening;

the cabinet body is internally provided with a second exhaust channel which is positioned at the side part of the operation cavity and communicated with the first exhaust outlet so as to exhaust the air in the laboratory to the outside of the laboratory, the second exhaust channel is positioned at one side close to the first exhaust outlet, a second closed valve is arranged between the upper opening of the second exhaust channel and the first exhaust outlet, and the side wall of the cabinet body is provided with a second exhaust outlet communicated with the second exhaust channel;

when the first sealing valve is in an open state, the second sealing valve is in a closed state; when the first sealing valve is in a closed state, the second sealing valve is in an open state.

2. The B2-type biosafety cabinet according to claim 1, wherein an exhaust filter corresponding to the second exhaust outlet is arranged in the cabinet body, and the exhaust filter adopts a high-efficiency filter.

3. The B2-type biosafety cabinet according to claim 1, wherein the first exhaust channel is connected with the first exhaust outlet through a first bent connector, the first sealing valve is arranged between the first exhaust channel and the first bent connector, the second exhaust channel is connected with the first exhaust outlet through a second bent connector, the second sealing valve is arranged between the second exhaust channel and the second bent connector, a three-way connector is arranged at the first exhaust outlet, the first bent connector and the second bent connector are respectively connected with two opposite ends of the three-way connector, and the first exhaust outlet is connected with a third end of the three-way connector.

4. The B2-type biosafety cabinet according to claim 2, further comprising a PLC controller, wherein the PLC controller is electrically connected to the first sealing valve and the second sealing valve, and a control panel electrically connected to the PLC controller is embedded in a front side wall of the cabinet body, and the control panel is located above the operation cavity.

5. The B2-type biosafety cabinet according to claim 1, wherein exhaust holes communicated with the first exhaust channel are respectively formed in two side cavity walls and a rear side cavity wall of the operation cavity, and the exhaust holes are arranged at the lower part of the operation cavity.

6. The B2-type biosafety cabinet according to claim 4, wherein a sterilizing component and a leak detecting component are further disposed above the first exhaust channel, the sterilizing component is used for sterilizing the first filter in situ, the leak detecting component is used for detecting leak of the first filter in situ, and the sterilizing component and the leak detecting component are electrically connected with the PLC controller respectively.

7. The B2 biosafety cabinet of claim 6 wherein said sanitizing assembly includes vapor ejection elements and sanitizing detection elements spaced along the extension of said first filter, said vapor ejection elements capable of releasing VHP vapor to sanitize said first filter, said sanitizing detection elements capable of monitoring an effect parameter of said first filter and transmitting said effect parameter to said PLC controller.

8. A B2 biosafety cabinet in accordance with claim 6 wherein said leak detection assembly includes a smoker disposed on one side of said first filter, a scanning element disposed above said first filter for scanning said first filter line by line, and a sampling element disposed above said first filter and connected to said scanning element.

9. The B2 biosafety cabinet of claim 6, wherein said supply filter, said exhaust filter, and said first filter are each provided with a differential pressure gauge for monitoring a differential pressure parameter, said differential pressure gauge being electrically connected to said PLC controller for transmitting said differential pressure parameter to said PLC controller.

10. A B2 biosafety cabinet according to claim 2, wherein an access door communicating with said second exhaust channel is hinged to a front side wall of said cabinet body, said access door corresponding to said exhaust filter in front-rear direction.

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