CN216742895U

CN216742895U - Manual air volume adjusting valve and biosafety cabinet

Info

Publication number: CN216742895U
Application number: CN202123382638.0U
Authority: CN
Inventors: 沈科优; 吴高
Original assignee: Daer Guangzhou Biotechnology Co ltd
Current assignee: Daer Guangzhou Biotechnology Co ltd
Priority date: 2021-12-29
Filing date: 2021-12-29
Publication date: 2022-06-14
Anticipated expiration: 2031-12-29

Abstract

The application relates to the technical field of air volume valves, and discloses a manual air volume regulating valve which comprises a box body, a fan guide blade assembly, a rotating fastener, a rotating handle and a hand screwing fastener, wherein the box body is provided with an air outlet; the air guide blade assembly can be connected in the box body in a swinging mode and is close to the air outlet, and can swing up and down relative to the box body to adjust the airflow flow of the air outlet; the rotary fastener is rotatably connected to the box body; the rotary handle is connected with the air guide blade assembly through a rotary fastener and can swing to adjust the air guide blade assembly to swing up and down relative to the air outlet in a reciprocating manner; the rotary handle is provided with an arc opening by taking the rotary fastener as a center; angle scale lines are arranged at the positions of the rotary handle for the circular arc holes; the hand tightening fastener penetrates through the arc opening to be connected with the box body. The manual air volume adjusting valve for accurately adjusting the air flow of the air outlet is simple in structure, convenient and fast to operate, low in cost and time-saving and labor-saving; also provides a biological safety cabinet with the manual air volume adjusting valve.

Description

Manual air volume adjusting valve and biosafety cabinet

Technical Field

The utility model relates to the technical field of air volume valves, in particular to a manual air volume adjusting valve and a biological safety cabinet.

Background

The biological safety cabinet generally comprises a cabinet body, a descending filter, a fan and an outward discharge filter, wherein the descending filter, the fan and the outward discharge filter are arranged in the cabinet body; the working principle of the biological safety cabinet is that after outside air is filtered by a descending filter, vertical airflow is formed and vertically enters the safety cabinet, so that a processed sample is prevented from being polluted; and then the air in the cabinet body is sucked outwards by the fan to keep the negative pressure state in the cabinet body, and then the air in the cabinet body is filtered by the outward discharge filter to form outward discharge airflow and then is discharged into the atmosphere to protect the environment. The biological safety cabinet needs stable airflow flow ratio, namely about 70% of vertical descending airflow flow and 30% of outward exhaust airflow flow, however, the airflow flow ratio is easily affected by various factors, and if individual factors suddenly change, the airflow flow ratio can be broken, and the operation of airflow flow ratio needs to be repeated. The existing biological safety cabinet mainly utilizes a descending filter and an outward-discharging filter to realize air flow ratio, but because the descending filter and the outward-discharging filter are easy to have processing errors, resistance balance is difficult to achieve, even the filter needs to be replaced for trial assembly, the air flow of the biological safety cabinet is close to a set value, the process is complex to operate, data is repeatedly detected, the time and cost needed to be spent are too high, and the effect of quick and accurate adjustment cannot be achieved.

SUMMERY OF THE UTILITY MODEL

The utility model aims to overcome the problems of the prior art, provides a manual air volume adjusting valve which can accurately adjust the air flow of an air outlet, is convenient to operate, saves time and labor and has low cost, and also provides a biological safety cabinet with the manual air volume adjusting valve.

In order to achieve the purpose, the utility model adopts the following scheme:

a manual air volume adjusting valve comprises a box body, wherein the upper end of the box body is provided with an air outlet communicated with a cavity of the box body; the manual air volume adjusting valve also comprises a wind guide blade assembly, a rotating fastener, a rotating handle and a hand screwing fastener;

the air guide blade assembly can be connected in the box body in a swinging mode and is close to the air outlet, and can swing in the vertical direction relative to the box body to adjust the airflow flow of the air outlet;

the rotary fastener is rotatably connected to the box body;

the rotary handle is connected with the air guide blade assembly through the rotary fastener and can swing to adjust the air guide blade assembly to swing up and down relative to the air outlet in a reciprocating manner;

the rotary handle is provided with an arc-shaped opening by taking the rotary fastener as a center; angle scale lines are arranged at the positions of the rotary handle for the circular arc holes;

the hand tightening fastener penetrates through the arc opening hole to be connected with the box body and used for unlocking or locking the rotating handle.

Furthermore, the fan blade assembly is connected with the box body in a swinging mode through a supporting piece; the support comprises a support frame; the two support frames are arranged on two sides in the box body and are close to the air outlet; the guide blade assembly can be connected between the two support frames in a swinging mode.

Further, the rotating handle comprises a swinging part and a long handle; the swinging part is connected with the air guide blade assembly through the rotating fastener; the circular arc opening is positioned on the swinging part; the angle scale lines are arranged on the swinging part and are positioned above the arc openings; the range of the angle scale mark is 0-90 degrees; when the long handle corresponds to the angle scale mark of 0 degree, the long handle is vertical to the ground, and the hand tightening fastener is in contact with one end of the circular arc opening; when the long handle corresponds to the 90-degree angle scale line, the long handle is parallel to the ground, and the hand tightening fastener is in contact with the other end of the circular arc opening.

Further, the air guide blade assembly comprises a driving blade, a driven blade and a linkage rod; one end of the driving blade is connected with one support frame in a swinging mode, and the other end of the driving blade is connected with the rotating fastener;

the plurality of driven blades are distributed along the length direction of the supporting frames and can be connected between the two supporting frames in a swinging mode;

the driving blade is in linkage connection with the plurality of driven blades through the linkage rod so that the driven blades synchronously swing along with the driving blade relative to the box body in the vertical direction to adjust the airflow flow of the air outlet.

Furthermore, the driving blade and the support frame, the driven blade and the support frame, the driving blade and the linkage rod and the driven blade and the linkage rod are connected in a swinging mode through a blocking screw.

Further, the active blade includes a first blade main body, a first connection plate, and a first mounting plate; two opposite first connecting plates are respectively and vertically connected to two ends of one side of the first blade main body; the first mounting plate is connected to the other side of the first blade main body;

the driven blade comprises a second blade body, a second connecting plate and a second mounting plate; two opposite second connecting plates are respectively and vertically connected to two ends of one side of the second blade main body; the second mounting plate is connected to the other side of the second blade body;

the first connecting plate at one end of the first blade main body is connected with one of the support frames, the second connecting plate is connected with the support frames, the first connecting plate is connected with the linkage rod, and the second connecting plate is connected with the linkage rod in a swinging mode through the blocking screw.

Further, the first blade main body and the two first connecting plates are integrally bent and formed; the second blade main body and the two second connecting plates are integrally bent and formed.

Further, the rotating fastener comprises a double-headed screw and a lock nut; the double-head screw is rotatably connected to the box body; one end of the double-head screw penetrates through the fan guide blade assembly to be matched and fixedly connected with one locking nut; the other end of the handle penetrates through the rotary handle to be matched and fastened with the other locking nut.

Further, the hand tightening member is a hand bolt.

Furthermore, the top end face of the box body is provided with an air guide pipe body communicated with the air outlet.

The utility model also provides a biological safety cabinet, which comprises a cabinet body and the manual air volume adjusting valve; the manual air volume adjusting valve is arranged on the cabinet body and communicated with the inner cavity of the cabinet body.

Compared with the prior art, the utility model has the following advantages:

according to the utility model, the rotary handle is provided with the arc-shaped opening by taking the rotary fastener as the center, the angle scale lines are arranged at the position corresponding to the arc-shaped opening, the swing of the rotary handle is limited by combining the arc-shaped opening and the hand tightening fastener, so that the rotary handle can only do reciprocating swing within the angle range in the arc-shaped opening, after the rotary handle is swung and adjusted to a proper angle, the rotary handle can be locked by the hand tightening fastener to prevent the rotary handle from swinging, and further, the angle of the fan blade assembly which can do reciprocating swing relative to the vertical direction of the air outlet can be accurately adjusted, so that the effect of more accurately adjusting the airflow flow of the air outlet is achieved, meanwhile, the auxiliary relevant records are favorably made, the data is provided for subsequent operation, the structure is simple, the operation is convenient and fast, the cost is low, and the time and labor are saved.

Drawings

The present application will be described in further detail with reference to the following drawings and detailed description.

Fig. 1 is a schematic perspective view of a manual air volume adjusting valve according to the present invention.

Fig. 2 is a partial perspective view of the manual air volume adjusting valve of the present invention.

Fig. 3 is a schematic structural diagram of the biosafety cabinet of the utility model.

The figure includes:

the air guide device comprises a box body 1, an air outlet 2, an air guide blade assembly 3, a driving blade 31, a first blade main body 311, a first connecting plate 312, a first mounting plate 313, a driven blade 32, a second blade main body 321, a second connecting plate 322, a second mounting plate 323, a linkage rod 33, a rotating fastener 4, a double-end screw 41, a locking nut 42, a rotating handle 5, a long handle 51, a swinging part 52, a hand screwing fastener 6, an arc opening 7, a supporting piece 8, a supporting frame 81, a plugging screw 9, an air guide pipe body 10, a cabinet body 20 and angle scale lines 30.

Detailed Description

The following detailed description of embodiments of the present invention is provided in connection with the accompanying drawings and examples. The following examples are intended to illustrate the utility model, but are not intended to limit the scope of the utility model.

As shown in fig. 1 to 3, a manual air volume adjusting valve comprises a box body 1, wherein an air outlet 2 communicated with a cavity of the box body 1 is arranged at the upper end of the box body 1; the manual air volume adjusting valve also comprises a wind guide blade assembly 3, a rotating fastener 4, a rotating handle 5 and a hand screwing fastener 6; the fan blade assembly 3 can be connected in the box body 1 in a swinging mode and is close to the air outlet 2, and can swing in the vertical direction relative to the box body 1 to adjust the airflow of the air outlet 2; the rotary fastener 4 is rotatably connected to the box body 1; the rotary handle 5 is connected with the fan blade assembly 3 through the rotary fastener 4, and can swing to adjust the fan blade assembly 3 to swing up and down relative to the air outlet 2; the rotary handle 5 is provided with an arc-shaped opening 7 by taking the rotary fastener 4 as a center; the position of the rotary handle 5 to the arc open hole 7 is provided with angle scale lines 30; preferably, the angle graduation marks 30 are printed on the rotating handle 5 by etching; the hand tightening piece 6 penetrates through the arc opening 7 to be connected with the box body 1 and used for unlocking or locking the rotating handle 5. When the rotating handle 5 is adjusted in a swinging mode, the arc opening 7 rotates by taking the rotating fastener 4 as a center, and when the hand tightening fastener 6 is in contact with one end or the other end of the arc opening 7, the rotating handle 5 can be limited to continue to adjust in the swinging mode, and the angle range of the rotating handle 5 in the arc opening 7 is limited to adjust in the reciprocating swinging mode. Wherein the hand-tightening fastener 6 is a hand-tightening bolt; preferably, the head part of the hand-screwed bolt is of a butterfly type, so that the rotary handle 5 can be conveniently screwed and unlocked, the rotary handle 5 can be adjusted in a swinging mode, or the rotary handle 5 can be locked to prevent the rotary handle 5 from swinging.

The manual air volume adjusting valve swings through a rotating handle 5 to adjust a rotating fastener 4 to rotate, and then drives a fan guide blade assembly 3 to reciprocate relative to the up-down direction of the air outlet 2; an arc opening 7 is formed in the rotary handle 5 by taking the rotary fastener 4 as a center, angle scale lines 30 are arranged at the position corresponding to the arc opening 7, the arc opening 7 and the hand tightening fastener 6 are combined to limit the swing of the rotary handle 5, so that the rotary handle 5 can only swing back and forth within the angle range of the arc opening 7, when the rotary handle 5 is swung and adjusted to a proper angle, the swing handle 5 can be locked by tightening the hand tightening member 6, to prevent the swing handle 5 from swinging, further accurately adjusting the angle of the air guide blade component 3 which can swing back and forth relative to the up-and-down direction of the air outlet 2, achieving the effect of more accurately adjusting the airflow flow of the air outlet 2, meanwhile, the auxiliary recording device is helpful for assisting in making relevant records, provides data for subsequent operation, and has the advantages of simple structure, convenience in operation, low cost and time and labor saving effects.

The fan guide blade assembly 3 is connected into the box body 1 in a swinging mode through a supporting piece 8; the support 8 comprises a support frame 81; the two support frames 81 are arranged on two sides in the box body 1 and are close to the air outlet 2; the wind guide blade assembly 3 can be connected between the two support frames 81 in a swinging mode. The two support frames 81 realize the stable swing connection of the air guide blade component 3, so that the air flow of the air guide blade component 3 to the air outlet 2 can be stably adjusted.

In this embodiment, the air guide vane assembly 3 includes a driving vane 31, a driven vane 32 and a linkage rod 33; one end of the driving blade 31 is connected with one support frame 81 in a swinging way, and the other end of the driving blade is connected with the rotating fastener 4; the plurality of driven blades 32 are arranged along the length direction of the support frames 81 and can be connected between the two support frames 81 in a swinging manner; the driving blade 31 is linked with the plurality of driven blades 32 through the linkage rod 33 so that the driven blades 32 synchronously swing along with the driving blade 31 relative to the box body 1 in the vertical direction to adjust the airflow rate of the air outlet 2. The swinging handle is utilized to control the swinging angle of the air guide blade assembly 3, the swinging handle is adopted to swing and adjust the rotating fastener 4 to rotate, so that the driving blade 31 is driven to swing back and forth relative to the air outlet 2 in the vertical direction, under the transmission of the linkage rod 33, the plurality of driven blades 32 also swing back and forth along with the driving blade 31 relative to the air outlet 2 in the vertical direction, and the air flow of the air outlet 2 is adjusted. And moreover, the plurality of driven blades 32 are combined with the driving blade 31, and a multi-blade mode is adopted, so that the air quantity can be more accurately adjusted, compared with a single large blade, the rotating radius of each blade of the embodiment is smaller, the space is saved, and the height of the manual air quantity adjusting valve is reduced. Therefore, when the biological safety cabinet is limited by the height of a place, the manual air volume adjusting valve can save the height space and avoid the biological safety cabinet from being limited by the height.

In the present embodiment, the rotating handle 5 includes a swinging portion 52 and a long handle 51; the swinging part 52 is connected with the air guide blade assembly 3 through the rotating fastener 4; the circular arc opening 7 is positioned on the swinging part 52; the angle scale mark 30 is arranged on the swinging part 52 and is positioned above the circular arc opening 7; the range of the angle scale line 30 is 0-90 degrees; when the long handle 51 corresponds to the angle scale mark of 0 degree, the long handle 51 is vertical to the ground, and the hand-screwed fastener 6 is in contact with one end of the circular arc open hole 7; when the long handle 51 corresponds to the 90-degree angle scale line, the long handle 51 is parallel to the ground, and the hand tightening part 6 is in contact with the other end of the circular arc opening 7. The rotation angles of the driving blade 31 and the driven blade 32 are controlled by the rotating handle 5, namely in the swinging process of the swinging handle, when the long handle 51 of the rotating handle 5 is vertical to the ground, the hand tightening fastener 6 is contacted with one end of the arc opening 7, the driving blade 31 and the driven blade 32 are both parallel to the top surface of the air outlet 2, the air outlet 2 is completely closed, the outward discharge resistance is maximum, and the air flow rate is 0%; when the long handle 51 of the rotating handle 5 is parallel to the ground, the hand tightening fastener 6 is in contact with the other end of the circular arc opening 7, the driving blade 31 and the driven blade 32 are both vertical to the top surface level of the air outlet 2, the air outlet 2 is completely opened, the outward discharge resistance is minimum, and the air flow rate is 100%.

In the experiment of the biological installation cabinet, in order to design a good airflow ratio, when the long handle 51 corresponds to the angle scale mark of 30 degrees, the included angle formed by the driving blade 31 and the top surface of the air outlet 2 and the included angle formed by the driven blade 32 and the top surface of the air outlet 2 are both 30 degrees, so that the optimal airflow ratio is achieved.

Preferably, the driving blade 31 and the supporting frame 81, the driven blade 32 and the supporting frame 81, the driving blade 31 and the linkage rod 33, and the driven blade 32 and the linkage rod 33 are connected in a swinging manner through the driving screws 9. The driving blade 31 and the driven blade 32 are both connected on the supporting frame 81 by adopting the plug beating screw 9, the driving blade 31 and the plug beating screw 9 are also adopted between the linkage rods 33 and between the driven blade 32 and the linkage rods 33 for stable connection, and the driving blade 31 and the plug beating screw 9, the driven blade 32 and the plug beating screw 9 and the linkage rods 33 and the plug beating screw 9 are in clearance fit, are relatively movable, and enable the plurality of driven blades 32 to synchronously swing up and down along with the driving blade 31 relative to the air outlet 2 so as to adjust the airflow of the air outlet 2.

Specifically, the driving blade 31 includes a first blade body 311, a first connecting plate 312, and a first mounting plate 313; two opposite first connecting plates 312 are respectively and vertically connected to two ends of one side of the first blade body 311; the first mounting plate 313 is connected to the other side of the first blade body 311; the driven blade 32 includes a second blade body 321, a second connecting plate 322, and a second mounting plate 323; two opposite second connecting plates 322 are respectively and vertically connected to two ends of one side of the second blade main body 321; the second mounting plate 323 is coupled to the other side of the second blade body 321; the first connecting plate 312 at one end of the first blade body 311 is swingably connected with one of the support frames 81, the second connecting plate 322 is connected with the support frame 81, the first connecting plate 312 is connected with the linkage rod 33, and the second connecting plate 322 is connected with the linkage rod 33 through the setscrew 9. Through set up first connecting plate 312 and first mounting panel 313 on first blade main part 311, set up second connecting plate 322 and second mounting panel 323 on second blade main part 321, make things convenient for between first blade main part 311 and the support frame 81, but realize swinging between second blade main part 321 and the support frame 81 and be connected to and can take place the linkage between first blade main part 311 and the second blade main part 321, make a plurality of second blade main parts 321 along with the synchronous reciprocal swing of upper and lower direction relative air exit 2 of first blade main part 311, in order to adjust the airflow flow of air exit 2 is connected stably, simple structure. The turning handle 5 controls the turning angles of the driving blade 31 and the driven blade 32, and mainly controls the turning angles of the first blade body 311 and the second blade body 321.

In order to accelerate the production and improve the production efficiency, the first blade main body 311 and the two first connecting plates 312 are integrally bent and formed; the second blade main body 321 and the two second connecting plates 322 are integrally formed by bending. And driving vanes 31, driven vanes 32. The steel plate is made of metal materials such as stainless steel and has good durability and rigidity.

In order to realize the transmission connection between the swinging handle and the air guide blade assembly 3, the rotating fastening piece 4 comprises a double-thread screw rod 41 and a locking nut 42; the double-end screw 41 is rotatably connected to the box body 1; one end of the double-end screw rod 41 penetrates through the fan guide blade assembly 3 to be matched and fixedly connected with one locking nut 42; the other end passes through the rotating handle 5 to be matched and tightly connected with the other locking nut 42. Through setting up double-end screw 41 on box 1, as the rotation axis, the both ends of double-end screw 41 are connected with pendulum handle and wind guide vane subassembly 3 respectively, adopt two lock nut 42 to lock fixedly, simple structure, connect stably.

In the present embodiment, an air guide pipe 10 communicating with the air outlet 2 is provided on the top end surface of the casing 1. The box body 1 and the air guide pipe body 10 can be separated and fixed through screws. The air guide pipe body 10 is connected with the external air pipe, the screws can be detached if the biological safety cabinet is required to be moved independently, the external air pipe does not need to be detached, the connection is stable, and the disassembly and the assembly are convenient.

To sum up, the embodiment of the present invention provides a manual air volume adjusting valve, wherein the manual air volume adjusting valve swings through a rotating handle 5 to adjust a rotating fastener 4 to rotate, so as to drive a fan guide blade assembly 3 to swing up and down relative to an air outlet 2; an arc opening 7 is formed in the rotary handle 5 by taking the rotary fastener 4 as a center, angle scale lines 30 are arranged at the position corresponding to the arc opening 7, the arc opening 7 and the hand tightening fastener 6 are combined to limit the swing of the rotary handle 5, so that the rotary handle 5 can only swing back and forth within the angle range of the arc opening 7, when the rotary handle 5 is swung and adjusted to a proper angle, the swing handle 5 can be locked by tightening the hand tightening member 6, to prevent the swing handle 5 from swinging, thereby accurately adjusting the angle of the air guide blade component 3 which can swing back and forth relative to the up and down direction of the air outlet 2, achieving the effect of more accurately adjusting the airflow flow of the air outlet 2, meanwhile, the auxiliary recording device is helpful for assisting in making relevant records, provides data for subsequent operation, and has the advantages of simple structure, convenience in operation, low cost and time and labor saving effects.

The utility model also provides a biological safety cabinet, which comprises a cabinet body 20 and the manual air volume adjusting valve; the manual air volume adjusting valve is arranged on the cabinet body 20 and communicated with the inner cavity of the cabinet body 20. Through set up this manual air regulation valve on the cabinet body 20, can avoid biological safety cabinet to receive the restriction of height, and can the reciprocal wobbling angle of upper and lower direction that can accurate regulation fan blade assembly 3 relative air exit 2, reach the effect of the airflow of more accurate regulation air exit 2, thereby can reach the best airflow ratio, make biological safety cabinet have stable experimental environment, and simultaneously, help supplementary relevant record of making, for follow-up operation, provide data, moreover, the steam generator is simple in structure, the operation is convenient, time saving and labor saving. When the air conditioner is not used, the manual air volume adjusting valve is convenient to close, the situation that the filter in the cabinet body 20 is always in contact with the outside is prevented, and the service life of the filter in the cabinet body 20 is shortened.

The foregoing is only a preferred embodiment of the present application, and it should be noted that, for those skilled in the art, several modifications and substitutions can be made without departing from the technical principle of the present application, and these modifications and substitutions should also be regarded as the protection scope of the present application.

Claims

1. A manual air volume adjusting valve comprises a box body, wherein the upper end of the box body is provided with an air outlet communicated with a cavity of the box body; the manual air volume adjusting valve is characterized by further comprising a fan blade assembly, a rotating fastener, a rotating handle and a hand screwing fastener;

the air guide blade assembly can be connected in the box body in a swinging mode and is close to the air outlet, and can swing relative to the box body in the up-down direction to adjust the air flow of the air outlet;

the rotary fastener is rotatably connected to the box body;

2. The manual air volume adjusting valve according to claim 1, wherein the air guide blade assembly is connected with the box body in a swinging manner through a support piece; the support comprises a support frame; the two support frames are arranged on two sides in the box body and are close to the air outlet; the guide blade assembly can be connected between the two support frames in a swinging mode.

3. The manual air volume adjusting valve of claim 2, wherein the air guide blade assembly comprises a driving blade, a driven blade and a linkage rod; one end of the driving blade is connected with one support frame in a swinging mode, and the other end of the driving blade is connected with the rotating fastener;

4. The manual air volume adjusting valve of claim 3, wherein the rotating handle comprises a swinging part and a long handle; the swinging part is connected with the air guide blade assembly through the rotating fastener; the circular arc opening is positioned on the swinging part; the angle scale line is arranged on the swinging part and is positioned above the circular arc open hole; the range of the angle scale mark is 0-90 degrees; when the long handle corresponds to the angle scale mark of 0 degree, the long handle is vertical to the ground, and the hand tightening fastener is in contact with one end of the circular arc opening; when the long handle corresponds to the 90-degree angle scale line, the long handle is parallel to the ground, and the hand tightening fastener is in contact with the other end of the circular arc opening.

5. The manual air volume adjusting valve of claim 3, wherein the driving blade and the supporting frame, the driven blade and the supporting frame, the driving blade and the linkage rod, and the driven blade and the linkage rod are connected in a swinging manner through a plug screw.

6. The manual air volume adjusting valve of claim 5, wherein the active vane includes a first vane main body, a first connecting plate, and a first mounting plate; two opposite first connecting plates are respectively and vertically connected to two ends of one side of the first blade main body; the first mounting plate is connected to the other side of the first blade main body;

7. The manual air volume adjusting valve of claim 6, wherein the first blade main body and the two first connecting plates are integrally formed by bending; the second blade main body and the two second connecting plates are integrally bent and formed.

8. The manual air volume adjusting valve of claim 1, wherein the rotating fastener comprises a double-threaded screw and a lock nut; the double-head screw is rotatably connected to the box body; one end of the double-threaded screw penetrates through the fan guide blade assembly to be matched and fixedly connected with one locking nut; the other end of the handle penetrates through the rotary handle to be matched and fastened with the other locking nut.

9. The manual air volume adjusting valve according to claim 1, wherein the hand-tightening fastener is a hand-tightening bolt; and the top end surface of the box body is provided with an air guide pipe body communicated with the air outlet.

10. A biosafety cabinet, which is characterized by comprising a cabinet body and a manual air volume adjusting valve according to any one of claims 1 to 9; the manual air volume adjusting valve is arranged on the cabinet body and communicated with the inner cavity of the cabinet body.