Biological safety cabinet

Abstract

The invention relates to the technical field of medical instruments, in particular to a biological safety cabinet which comprises a cabinet body, and a lower cavity used for containing automatic detection equipment and an upper cavity arranged above the lower cavity are arranged in a cabinet cavity of the cabinet body; an air supply device is arranged in the upper cavity, an air inlet of the air supply device is communicated with the upper cavity, an air outlet of the air supply device is communicated with the lower cavity, and an air inlet communicated with the outside is formed in the top or the peripheral side of the upper cavity; the side wall of the lower cavity comprises at least one cabinet door used for sealing the lower cavity, the cabinet door is a shell, an inner cavity of the shell forms an air return channel, a first ventilation structure is arranged on the inner side of the shell, and the bottom of the lower cavity and the air return channel are communicated through the first ventilation structure. A second ventilation structure is arranged at the top of the shell and communicates with the air return channel and the upper cavity. The air return channel is formed in the inner cavity of the cabinet door shell, the air return channel is large, an air pipe does not need to be additionally arranged, and it is guaranteed that airflow in the lower cavity used for containing the automatic equipment can flow evenly and fully.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and in particular to a biological safety cabinet. Background Art

[0002] In medical testing procedures such as blood testing, the application of automated equipment brings many advantages. First, automated equipment can quickly and accurately complete complex testing tasks, reduce errors that may be caused by human operation, and improve the reliability and consistency of test results. Secondly, the automated system can run continuously without being restricted by the time and intensity of manual operation, greatly improving the laboratory's testing capabilities. In addition, automated equipment can also integrate multiple testing modules to achieve one-stop multi-project testing, improving the overall work efficiency of the laboratory. The application of automated testing equipment in the medical field is becoming more and more extensive.

[0003] Biochemical tests such as blood tests often need to be performed in a sterile environment, so the corresponding automated testing equipment needs to be placed in a biosafety cabinet. The biosafety cabinet needs to maintain a sterile environment inside the cabinet by precisely controlling the airflow. The biosafety cabinet used to accommodate automated testing equipment is larger than ordinary biosafety cabinets, and the automated equipment will generate heat during operation. It is important to ensure that the temperature inside the biosafety cabinet is appropriate and that the airflow in the cabinet is even and sufficient for the biosafety cabinet used to place automated equipment.

[0004] The Chinese utility model patent with the authorization announcement number CN215087236U discloses an energy-saving biological safety cabinet, including a cabinet and a filtering system. The cabinet is provided with an air inlet and an air outlet connected to its working area. The filtering system includes an air supply component connected to the air inlet, an air outlet component connected to the air outlet, and a fan. A return pipe is connected between the air supply component and the air outlet component, and a one-way valve is provided on the return pipe. The gas in the working area of ​​the cabinet is circulated under the operation of the filtering system, and the hot air flow discharged from the air outlet component returns to the air supply component through the return pipe, and returns to the cabinet again through the air supply component, so that the temperature in the biological safety cabinet remains stable.

[0005] However, the biosafety cabinet used to set up automated testing equipment has a large cabinet size, which requires a large flow rate during air exchange. A return pipe is used to transport the air in the cabinet, which requires the return pipe to be set larger and the air inlet distribution range of the return pipe is small, making it difficult to ensure uniform and sufficient airflow in the cabinet. Summary of the invention

[0006] The technical problem to be solved by the present invention is that the existing biological safety cabinet circulates the air in the cabinet to the air inlet through a conduit, and the air inlet distribution range of the return pipe is small, making it difficult to ensure uniform and sufficient air flow in the cabinet.

[0007] In order to solve the above technical problems, the purpose of the present invention is to provide a biological safety cabinet, including a cabinet body, wherein a lower chamber for placing an automated detection device and an upper chamber arranged above the lower chamber are provided in the cabinet cavity of the cabinet body; an air supply device is provided in the upper chamber, an air inlet of the air supply device is communicated with the upper chamber, an air outlet of the air supply device is communicated with the lower chamber, and an air inlet communicating with the outside is provided on the top or the peripheral side of the upper chamber;

[0008] The side wall of the lower chamber includes at least one cabinet door for sealing the lower chamber, and the cabinet door is a shell. The inner cavity of the shell forms a return air channel. A first ventilation structure is provided on the inner side of the shell, and the first ventilation structure connects the bottom of the lower chamber with the return air channel; a second ventilation structure is provided on the top of the shell, and the second ventilation structure connects the return air channel with the upper chamber.

[0009] As a preferred solution, the biosafety cabinet comprises a static pressure box and a first filter plate, wherein the static pressure box is installed at the upper part of the cabinet cavity, and the box wall of the static pressure box divides the cabinet cavity into the upper chamber and the lower chamber;

[0010] The air outlet of the air supply device is communicated with the inner cavity of the static pressure box. The lower end of the static pressure box has a first air outlet. The first filter plate is arranged at the upper part of the lower chamber to block the first air outlet.

[0011] As a preferred solution, a second air outlet is provided at the upper end of the static pressure box, and a second filter plate for blocking the second air outlet is connected to the upper end of the static pressure box;

[0012] The filtering pressure of the first filter plate is the same as the filtering pressure of the second filter plate.

[0013] As a preferred solution, the biosafety cabinet further comprises a control system, a temperature sensor is provided in the lower chamber, a flow control valve is provided in the second air outlet, and the flow control valve, the temperature sensor and the air supply device are all electrically connected to the control system;

[0014] When the test value of the temperature sensor is too high, the control system controls the flow control valve to increase, and controls the air supply device to increase the air supply power; when the test value of the temperature sensor is too low, the control system controls the flow control valve to decrease, and controls the air supply device to decrease the air supply power.

[0015] As a preferred solution, a wind speed sensor is provided in the lower chamber, the wind speed sensor is arranged below the first filter plate, and the wind speed sensor is electrically connected to the control system;

[0016] When the test value of the wind speed sensor is low, the control system controls the air supply device to increase the air supply power; when the test value of the wind speed sensor is high, the control system controls the air supply device to reduce the air supply power.

[0017] As a preferred solution, the air outlet direction of the air supply device is arranged inclined toward the first filter plate.

[0018] As a preferred solution, a diffuser plate is provided at the upper portion of the lower chamber, the diffuser plate is arranged below the first filter plate, and a plurality of diffuser holes are provided at intervals on the diffuser plate.

[0019] As a preferred solution, a third filter plate for blocking the air inlet is provided at the air opening.

[0020] As a preferred solution, a magnetic sealing ring is fixed to the end of the cabinet door opposite to the door frame, and the magnetic sealing ring is adsorbed to the door frame.

[0021] As a preferred solution, the first ventilation structure is a plurality of return air holes dispersedly arranged at the inner lower part of the shell.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] The biosafety cabinet of the present invention comprises a cabinet body, wherein a lower chamber for placing automated detection equipment and an upper chamber arranged above the lower chamber are provided in the cabinet cavity of the cabinet body; an air supply device is provided in the upper chamber, an air inlet of the air supply device is communicated with the upper chamber, an air outlet of the air supply device is communicated with the lower chamber, and an air inlet communicated with the outside is provided on the top or the peripheral side of the upper chamber; a side wall of the lower chamber comprises at least one cabinet door for sealing the lower chamber, the cabinet door is a shell, an inner cavity of the shell forms a return air channel, a first ventilation structure is provided on the inner side of the shell, the first ventilation structure connects the bottom of the lower chamber with the return air channel; a second ventilation structure is provided on the top of the shell, the second ventilation structure connects the return air channel with the upper chamber; in the present application, the cabinet door is arranged as a shell, the inner cavity of the shell forms a return air channel, the return air channel is large and does not require an additional air duct, thereby ensuring that the airflow in the lower chamber for placing the automated equipment can flow evenly and fully. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a front view of the biological safety cabinet of the present invention;

[0025] Figure 2 for Figure 1 Middle AA section view;

[0026] Figure 3 for Figure 1 Middle BB section;

[0027] Figure 4is a side view of the biological safety cabinet of the present invention;

[0028] Figure 5 for Figure 4 Mid-CC section;

[0029] Figure 6 It is a structural diagram of the cabinet door;

[0030] Figure 7 for Figure 6 Middle DD section;

[0031] Figure 8 for Figure 7 A partial enlarged view of point E in the middle;

[0032] In the figure, 1, cabinet body, 11, lower chamber, 12, upper chamber, 121, air inlet, 13, cabinet door, 131, return air duct, 132, return air hole, 133, inner plate body, 134, outer plate body, 135, long groove, 2, fan, 3, static pressure box, 31, box body, 311, first air outlet, 312, second air outlet, 32, flange plate, 41, first filter plate, 42, second filter plate, 43, third filter plate, 5, diffuser plate, 6, magnetic sealing ring. DETAILED DESCRIPTION

[0033] The specific implementation of the present invention is further described in detail below in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0034] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "left", "right", "top", "bottom", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. It should be understood that the terms "first", "second", etc. are used in the present invention to describe various information, but such information should not be limited to these terms, which are only used to distinguish the same type of information from each other. For example, without departing from the scope of the present invention, the "first" information may also be referred to as the "second" information, and similarly, the "second" information may also be referred to as the "first" information.

[0035] like Figures 1 to 8As shown, a preferred embodiment of the biosafety cabinet of the present invention comprises a cabinet body 1, wherein a lower chamber 11 for placing an automated detection device and an upper chamber 12 arranged above the lower chamber 11 are provided in the cabinet cavity of the cabinet body 1; an air supply device is provided in the upper chamber 12, an air inlet of the air supply device is communicated with the upper chamber 12, an air outlet of the air supply device is communicated with the lower chamber 11, and an air inlet 121 communicating with the outside is provided on the top or the peripheral side of the upper chamber 12; a side wall of the lower chamber 11 comprises at least one cabinet door 13 for sealing the lower chamber 11, the cabinet door 13 is a shell, an inner cavity of the shell forms a return air channel 131, a first ventilation structure is provided on the inner side of the shell, the first ventilation structure communicates the bottom of the lower chamber 11 with the return air channel 131; a second ventilation structure is provided on the top of the shell, the second ventilation structure communicates the return air channel 131 with the upper chamber 12. By setting the cabinet door 13 as a shell, the inner cavity of the shell forms a return air channel 131, which is relatively large and does not require an additional air duct, thereby ensuring that the airflow in the lower chamber 11 for placing the automation equipment can flow evenly and fully.

[0036] Among them, the first ventilation structure is a plurality of return air holes 132 dispersedly arranged at the inner lower part of the shell, and the second ventilation structure is a long groove 135 opened at the upper part of the cabinet door 13, and the long groove 135 extends along the width direction of the cabinet door 13. The long groove 135 can be set on the top wall of the cabinet door 13 or on the upper end of the side wall of the cabinet door 13. In this embodiment, the cabinet door 13 includes a square frame, an inner plate body 133 arranged on the inner side of the square frame, and an outer plate body 134 arranged on the outer side of the square frame. The inner plate body 133 is made of 304 stainless steel plate, and each return air hole 132 is arranged at the lower part of the 304 stainless steel plate. The 304 stainless steel plate has strong durability and corrosion resistance, which ensures the durability of the cabinet door 13. The outer plate body 134 is treated with cold plate spraying to ensure that the cabinet door 13 is beautiful and rust-proof. The inner plate body 133 and the square frame, and the outer plate body 134 and the square frame are connected by a snap-on method. The inner plate 133, the outer plate 134 and the square frame enclose a return air passage 131. The return air holes 132 are square holes with a length of 10 mm and a width of 40 mm, and the return air holes 132 are distributed in a matrix.

[0037] In order to ensure the sealing of the cabinet door 13 after closing, in this embodiment, a magnetic sealing ring 6 is fixed at one end of the cabinet door 13 opposite to the door frame, and the magnetic sealing ring 6 adsorbs the door frame. Specifically, the cabinet doors 13 are all outward-opening, and the biosafety cabinet includes a door frame arranged in the cabinet body 1 and arranged opposite to the cabinet door 13. The door frame is made of ferromagnetic material, and the cabinet door 13 is provided with a card slot adapted to the contour of the door frame on the peripheral side, and a sealing rubber ring is provided in the card slot, and a magnetic strip is embedded in the sealing rubber ring. When the cabinet door 13 is closed, the magnetic strip adsorbs the door frame, so that the sealing rubber ring is close to the door frame, thereby ensuring the sealing effect of the biosafety cabinet. Among them, the sealing rubber ring is made of soft polyvinyl chloride with good flexibility and elasticity.

[0038] In this embodiment, the cabinet 1 is a rectangular parallelepiped, and cabinet doors 13 are provided on the left side, right side and rear side of the cabinet 1, and each cabinet door 13 is a shell provided with a first ventilation structure and a second ventilation structure. The distribution range of the return air holes 132 is further increased.

[0039] In this embodiment, the biological safety cabinet includes a static pressure box 3 and a first filter plate 41. The static pressure box 3 is installed in the upper part of the cabinet cavity. The box wall of the static pressure box 3 divides the cabinet cavity into an upper chamber 12 and a lower chamber 11; the air outlet of the air supply device is connected to the inner cavity of the static pressure box 3, and the lower end of the static pressure box 3 has a first air outlet 311. The first filter plate 41 is arranged in the upper part of the lower chamber 11 to block the first air outlet 311. Specifically, the air supply device is a fan 2, and four fans 2 are provided. The four fans 2 are arranged at intervals around the circumference of the static pressure box 3. The air outlet of the fan 2 is provided with a trumpet-shaped diffusion structure, and the diffusion angle of the diffusion structure is 10°. After the four air supply devices inhale air, the air outlet of the fan 2 blows toward the inside of the static pressure box 3 at a diffusion angle of 10 degrees. This design ensures that wind reaches all areas inside the static pressure box 3, and improves the uniformity of the airflow. The first filter plate 41 is a high-efficiency filter with relatively high filtering accuracy. Under the resistance of the high-efficiency filter, the pressure of the wind entering the static pressure box 3 increases in the static pressure box 3, so that the wind is more evenly distributed in the static pressure box 3. The wind in the static pressure box 3 passes through the first filter plate 41 through the pressure to become clean air.

[0040] In order to ensure that the clean air can be evenly dispersed to various parts of the lower chamber 11, in this embodiment, a diffuser plate 5 is provided at the upper part of the lower chamber 11, and the diffuser plate 5 is arranged below the first filter plate 41. A plurality of diffuser holes are provided at intervals on the diffuser plate 5. The clean air is secondary diverted through the diffuser plate 5 so that it is more evenly distributed in various areas of the chamber, ensuring the air quality and circulation effect in the lower chamber 11. The setting of the diffuser plate 5 ensures that the clean air can be dispersed smoothly, avoids the generation of eddy currents or turbulence, and further improves the uniformity and stability of the airflow.

[0041] Limited by the building height of the installation area, the height of the biosafety cabinet needs to be controlled within a certain range, and the height of the lower chamber 11 as the working area needs to be set as high as possible, and the height of the upper chamber 12 should be set as low as possible. Therefore, the fan 2 used as the air supply device needs to be selected as a fan 2 with a smaller size, capable of overcoming greater resistance and having a certain air volume. This type of fan 2 is not only compact in size, but also can provide at least 2,500 cubic meters per hour of air volume under resistance conditions of 350 Pascal to 400 Pascal. This type of fan 2 is selected to ensure that the required air volume is achieved in a limited space and to overcome the total resistance of the equipment. In this embodiment, the static pressure box 3 includes a box body 31 with an opening facing downward, and a flange plate 32 extending horizontally outward is provided on the lower end edge of the box body 31. The edge of the flange plate 32 is connected to the inner wall of the cabinet body 1, thereby connecting the static pressure box 3 to the cabinet body 1, and the fan 2 is installed outside the side wall of the box body 31 and is located on the flange plate 32. If the air outlet of the fan 2 is arranged horizontally, the wind blown out from the fan 2 needs to be blocked by the box wall of the static pressure box 3 and then turned back to the first filter plate 41, which is not conducive to the efficient downward flow of the gas in the static pressure box 3 through the first filter plate 41. Moreover, when the air outlet is arranged horizontally, the air inlet of the fan 2 will be opposite to the flange plate 32 up and down, which will cause the distance between the air inlet of the fan 2 and the flange plate 32 to be too close, which is not conducive to air intake. In this embodiment, the air outlet direction of the air supply device is arranged inclined toward the first filter plate 41. Specifically, the air outlet of the fan 2 is arranged at a downward tilt of 5°, and the air inlet of the fan 2 is also arranged at an angle to the flange plate 32, which is conducive to improving the air intake efficiency of the fan 2, and the wind blown by the fan 2 is blown to the first filter plate 41 at an angle downward, which is conducive to improving the filtering efficiency of the first filter plate 41. In this embodiment, the air inlet of the fan 2 is arranged downward, and the air inlet of the fan 2 is spaced up and down from the flange plate 32. This is because when the air inlet of the fan 2 is downward, it can ensure that the axial direction of the fan wheel of the fan 2 is arranged vertically, so that the diameter direction of the fan wheel is close to the horizontal, so that the distance between the highest point of the fan 2 and the flange plate is small, thereby avoiding the installation height of the fan wheel being too high, and further reducing the total height of the biological safety cabinet of the present invention. In addition, the fan 2 is arranged obliquely so that the air inlet of the fan 2 and the flange plate 2 are arranged at an angle, avoiding the narrow air intake space caused by the air inlet of the fan 2 and the flange plate 2 facing each other up and down, which is conducive to the smooth air intake of the fan 2.

[0042] In this embodiment, four air supply devices are provided, and all of the four air supply devices are fans 2, and the four air supply devices are respectively arranged at the four left front sides, left rear side, right rear side and right front side of the box body 31, so that the gas in each part of the lower chamber 11 can flow back smoothly and efficiently. Thereby, the efficiency of the air circulation inside the entire cabinet 1 is improved. This distribution method also helps to reduce the airflow dead corners in the local area of ​​the lower chamber 11.

[0043] In this embodiment, a third filter plate 43 for blocking the air inlet 121 is provided at the air opening. The third filter plate 43 is a primary filter. The filtering accuracy of the third filter plate 43 is lower than that of the first filter plate 41, so as to achieve the primary filtering of the intake air. When each fan 2 is running, under the action of the fan 2, the airflow in the lower chamber 11 flows back to the upper chamber 12 through the return air channel 131. At the same time, the outside air flows into the upper chamber 12 from the air opening after being filtered by the third filter plate 43. The outside air and the return air are mixed and enter the static pressure box 3 under the action of the fan 2. The upper end of the static pressure box 3 is provided with a second air outlet 312. The upper end of the static pressure box 3 is connected to a second filter plate 42 for blocking the second air outlet 312. The filtering pressure of the first filter plate 41 is the same as the filtering pressure of the second filter plate 42.

[0044] During the operation of the biosafety cabinet, part of the gas in the static pressure box 3 flows to the lower chamber 11 through the first filter plate 41, and the other part flows to the outside through the second air outlet 312. The ratio of the amount of gas flowing into the lower chamber 11 to the amount of gas flowing out to the outside is the same as the ratio of the cross-sectional areas of the first air outlet 311 and the second air outlet 312. The gas flowing out of the working room from the second air outlet 312 is filtered by the second filter plate 42, thereby avoiding the outflow of microorganisms; the gas blown from the second air outlet 312 to the lower chamber 11 is filtered by the first filter plate 41, thereby meeting the gas cleanliness requirements of the working chamber. By setting the ratio of the cross-sectional areas of the first air outlet 311 and the second air outlet 312, the flow rate of the mixed gas in the static pressure box 3 to the lower chamber 11 can be controlled, thereby controlling the ventilation volume of the gas in the working chamber, and realizing the regulation of the flow rate and temperature of the gas in the working chamber.

[0045] The ventilation process of the biological safety cabinet of the present invention during operation is described in detail below, taking the air volume blown into the static pressure box 3 by each fan 2 as 100 cubic meters and the cross-sectional area ratio of the first air outlet 311 to the second air outlet 312 as 3:7 as an example. 70 cubic meters of gas entering the static pressure box 3 is filtered by the first filter plate 41 to form a first part of clean gas, and the first part of clean gas enters the lower chamber 11. Since the volume of the lower chamber 11 is constant, the first part of clean gas, in the process of flowing from the upper part of the lower chamber 11 to the lower part of the lower chamber 11, will make the original equal amount of gas in the lower chamber 11 flow into the return air channel 131 through the return air hole 132, and pass through the return air channel 132. 131 flows into the upper chamber 12, that is, the reflux amount of the original gas in the lower chamber 11 is also 70 cubic meters, the air output of each fan 2 is 100 cubic meters, and the air intake also needs to be 100 cubic meters. Therefore, the fresh air flowing into the upper chamber 12 from the air inlet 121 is 30 cubic meters, and the 30 cubic meters of fresh air and the 70 cubic meters of return air are mixed into the static pressure box 3. The gas circulates repeatedly to realize the circulation and renewal of the gas in the lower chamber 11, and then to maintain the gas temperature in the lower chamber 11. Through the above analysis, it can be seen that the amount of clean gas flowing out of the second air outlet 312 to the outside of the cabinet 1 is equal to the amount of fresh air flowing into the lower chamber 11 from the air inlet 121.

[0046] In order to adjust the temperature of the gas in the lower chamber 11, in this embodiment, the biosafety cabinet also includes a control system, a temperature sensor is provided in the lower chamber 11, and a flow control valve is provided in the second air outlet 312, and the flow control valve, the temperature sensor and the air supply device are all electrically connected to the control system; when the test value of the temperature sensor is high, the control system controls the flow control valve to increase, and controls the air supply device to increase the air supply power; increasing the flow control valve can increase the ratio of the cross-sectional area of ​​the second air outlet 312 to the first air outlet 311, thereby increasing the ratio of the amount of clean gas discharged to the outside of the cabinet 1 to the amount of clean gas flowing into the lower chamber 11, and at the same time, increasing the power of the air supply device, although entering The ratio of the clean gas in the lower chamber 11 to the clean gas flowing out of the cabinet 1 is reduced, but the total gas volume is increased. Therefore, the total amount of clean gas flowing into the lower chamber 11 can be kept unchanged, thereby keeping the ventilation speed in the lower chamber 11 constant; since the amount of fresh gas entering the lower chamber 11 from the air inlet 121 is equal to the amount of clean gas flowing out of the cabinet 1 from the second air outlet 312, the ratio of fresh air contained in the mixed gas in the static pressure box 3 is increased, thereby realizing the regulation of the temperature of the mixed gas in the static pressure box 3. When the test value of the temperature sensor is low, the control system controls the flow control valve to be reduced, and controls the air supply device to reduce the air supply power.

[0047] Furthermore, a wind speed sensor is provided in the lower chamber 11, and the wind speed sensor is arranged below the first filter plate 41. The wind speed sensor and the air supply device are electrically connected to the control system; when the test value of the wind speed sensor is low, the control system controls the air supply device to increase the air supply power; when the test value of the wind speed sensor is high, the control system controls the air supply device to reduce the air supply power.

[0048] Specifically, without changing the opening of the flow control valve, increasing the operating power of the fan 2 can increase the ventilation volume, and reducing the operating power of the fan 2 can reduce the ventilation volume, thereby achieving the adjustment of the air flow velocity in the lower chamber 11.

[0049] In summary, the biosafety cabinet of the present invention comprises a cabinet body 1, wherein a lower chamber 11 for placing an automated detection device and an upper chamber 12 arranged above the lower chamber 11 are provided in the cabinet cavity of the cabinet body 1; an air supply device is provided in the upper chamber 12, the air inlet of the air supply device is communicated with the upper chamber 12, the air outlet of the air supply device is communicated with the lower chamber 11, and an air inlet 121 communicating with the outside is provided at the top or the peripheral side of the upper chamber 12; the side wall of the lower chamber 11 comprises at least one cabinet door 13 for sealing the lower chamber 11, the cabinet door 13 is a shell, and the inner cavity of the shell forms a return air channel 131 A first ventilation structure is provided on the inner side of the shell, and the first ventilation structure connects the bottom of the lower chamber 11 with the return air channel 131; a second ventilation structure is provided on the top of the shell, and the second ventilation structure connects the return air channel 131 with the upper chamber 12; in the present application, the cabinet door 13 is set as a shell, and the inner cavity of the shell forms the return air channel 131, and the return air channel 131 is large and does not require an additional air duct, thereby ensuring that the airflow in the lower chamber 11 for placing the automation equipment can flow evenly and fully; the requirements for stable operation of the automation equipment in the biosafety cabinet and conducting biochemical experiments are met.

[0050] The above are only preferred embodiments of the present invention. It should be pointed out that, for ordinary technicians in this technical field, several improvements and substitutions can be made without departing from the technical principles of the present invention. These improvements and substitutions should also be regarded as the scope of protection of the present invention.

Claims

1. A biological safety cabinet, characterized in that: The cabinet (1) comprises a cabinet body, wherein a lower chamber (11) for placing an automated detection device and an upper chamber (12) arranged above the lower chamber (11) are provided in the cabinet cavity of the cabinet body (1); an air supply device is provided in the upper chamber (12); an air inlet of the air supply device is communicated with the upper chamber (12), an air outlet of the air supply device is communicated with the lower chamber (11), and an air inlet (121) communicating with the outside is provided at the top or the peripheral side of the upper chamber (12); The side wall of the lower chamber (11) comprises at least one cabinet door (13) for sealing the lower chamber (11); the cabinet door (13) is a shell; the inner cavity of the shell forms a return air channel (131); a first ventilation structure is provided on the inner side of the shell, and the first ventilation structure connects the bottom of the lower chamber (11) with the return air channel (131); and a second ventilation structure is provided on the top of the shell, and the second ventilation structure connects the return air channel (131) with the upper chamber (12).

2. The biological safety cabinet according to claim 1, characterized in that: The biological safety cabinet comprises a static pressure box (3) and a first filter plate (41), wherein the static pressure box (3) is installed at the upper part of the cabinet cavity, and the box wall of the static pressure box (3) divides the cabinet cavity into the upper chamber (12) and the lower chamber (11); The air outlet of the air supply device is connected to the inner cavity of the static pressure box (3), the lower end of the static pressure box (3) has a first air outlet (311), and the first filter plate (41) is arranged on the upper part of the lower chamber (11) to block the first air outlet (311).

3. The biological safety cabinet according to claim 2, characterized in that: The upper end of the static pressure box (3) is provided with a second air outlet (312), and the upper end of the static pressure box (3) is connected to a second filter plate (42) for blocking the second air outlet (312); The filtering pressure of the first filter plate (41) is the same as the filtering pressure of the second filter plate (42).

4. The biological safety cabinet according to claim 3, characterized in that: The biological safety cabinet further comprises a control system, a temperature sensor is provided in the lower chamber (11), a flow control valve is provided in the second air outlet (312), and the flow control valve, the temperature sensor and the air supply device are all electrically connected to the control system; When the test value of the temperature sensor is too high, the control system controls the flow control valve to increase, and controls the air supply device to increase the air supply power; when the test value of the temperature sensor is too low, the control system controls the flow control valve to decrease, and controls the air supply device to decrease the air supply power.

5. The biological safety cabinet according to claim 4, characterized in that: A wind speed sensor is provided in the lower chamber (11), the wind speed sensor is arranged below the first filter plate (41), and the wind speed sensor is electrically connected to the control system; When the test value of the wind speed sensor is low, the control system controls the air supply device to increase the air supply power; when the test value of the wind speed sensor is high, the control system controls the air supply device to reduce the air supply power.

6. The biological safety cabinet according to claim 2, characterized in that: The air outlet direction of the air supply device is arranged obliquely toward the first filter plate (41).

7. The biological safety cabinet according to claim 2, characterized in that: A diffuser plate (5) is provided at the upper portion of the lower chamber (11), the diffuser plate (5) is arranged below the first filter plate (41), and a plurality of diffuser holes are provided at intervals on the diffuser plate (5).

8. The biological safety cabinet according to claim 1, characterized in that: A third filter plate (43) for blocking the air inlet (121) is provided at the air opening.

9. The biological safety cabinet according to claim 1, characterized in that: A magnetic sealing ring (6) is fixed to the end of the cabinet door (13) opposite to the door frame, and the magnetic sealing ring (6) is attracted to the door frame.

10. The biological safety cabinet according to claim 1, characterized in that: The first ventilation structure is a plurality of return air holes (132) dispersedly arranged at the inner lower part of the shell.

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