A biosafety cabinet with adjustable exhaust volume

Abstract

This application belongs to the field of electrical technology, specifically relating to a biosafety cabinet with adjustable exhaust volume, including a cabinet body, an exhaust filter, an exhaust hood, a controller, and an adjustment component. The exhaust hood includes an exhaust hood one and an exhaust hood two sleeved outside the exhaust hood one. An air inlet gap is formed between the exhaust hood one and the exhaust hood two, connecting the interior and exterior of the exhaust hood two. The adjustment component is used to adjust the width of the air inlet gap. The controller acquires a first exhaust volume entering the first air chamber from the exhaust filter and a second exhaust volume entering the exhaust system, and controls the adjustment component to adjust the width of the air inlet gap. The biosafety cabinet with adjustable exhaust volume provided by this application can adjust the exhaust volume without affecting the downward air velocity, so that the inflow air volume meets the nominal inflow air volume of the biosafety cabinet.

Description

Technical Field

[0001] This application belongs to the field of biological experimental equipment technology, specifically relating to a biosafety cabinet with adjustable exhaust volume. Background Technology

[0002] In Class II biosafety cabinets, specifically the A2 type, the exhaust airflow is filtered and returned to the room. This exhaust airflow is typically drawn out through an exhaust system. An exhaust hood is usually installed at the exhaust filter of the biosafety cabinet, and a flexible connection is made between the hood and the exhaust system to guide the exhaust airflow. According to the requirements for A2 biosafety cabinets, the inflow airflow must equal the exhaust airflow. However, current building exhaust systems are complex, and there is a high probability that the exhaust airflow of the system for the biosafety cabinet and the cabinet's own exhaust airflow will be mismatched. This can result in the exhaust airflow being too large or too small, leading to an excessively high or low inflow air velocity. This can cause aerosols to easily spill out of the front window of the biosafety cabinet, endangering the personal safety of the user.

[0003] In related technologies, there are two main methods for controlling the exhaust volume of A2 biosafety cabinets with added exhaust hoods:

[0004] The first method is to control the exhaust system: adjust the exhaust volume of the exhaust system for the safety cabinet. This method requires the addition of various air valves and sensors to the exhaust system, which is costly. In addition, for some older buildings, the renovation of the HVAC system is also difficult, which will further increase the cost.

[0005] The second method is to control the exhaust volume of the safety cabinet itself: by increasing the speed of the fan inside the safety cabinet or adjusting the exhaust valve of the safety cabinet, the inflow air velocity of the safety cabinet can be made to meet the requirements. However, the resistance of the air supply and exhaust system of the safety cabinet is constant. Although this can make the inflow air velocity meet the requirements, it will cause the descent air velocity to be outside the nominal range, affecting the normal use of the safety cabinet.

[0006] While the first method mentioned above can address the mismatch between the exhaust system and the biosafety cabinet's exhaust volume to some extent, it is costly. The second method, while solving the problem of non-compliant exhaust volume, introduces a new issue: the downward airflow velocity deviates from the standard. Both methods have significant drawbacks. Therefore, there is an urgent need to find a new method to address the problem of biosafety cabinets having excessively high or low exhaust volumes, falling outside the nominal range. Summary of the Invention

[0007] This application provides a biosafety cabinet with adjustable exhaust volume to solve the problem that the exhaust volume of the above-mentioned biosafety cabinets is often too large or too small and is not within the nominal value range.

[0008] To solve the above problems, this application adopts the following technical solution:

[0009] This application provides a biosafety cabinet with adjustable exhaust volume, including a cabinet body, an exhaust filter, and an exhaust hood installed at the outlet end of the exhaust filter. The exhaust hood is connected to an exhaust system. The cabinet also includes a controller and an adjustment component. The exhaust hood includes an exhaust hood one and an exhaust hood two fitted over the exhaust hood one. The exhaust hood one forms a first air chamber communicating with the air inlet of the exhaust filter. One end of the exhaust hood two is connected to the exhaust system, and the other end communicates with the first air chamber. An air inlet gap is formed between the exhaust hood one and the exhaust hood two, communicating with the interior and exterior of the exhaust hood two. The adjustment component is used to adjust the width of the air inlet gap, and the controller is used to:

[0010] Obtain the first exhaust volume entering the first air chamber from the exhaust filter and the second exhaust volume entering the exhaust system;

[0011] The width of the air inlet gap is adjusted by controlling the regulating component based on the first exhaust volume and the second exhaust volume.

[0012] In one possible design, a first sensor is installed at the air outlet of the exhaust hood, and the controller is specifically used for:

[0013] The first exhaust volume is obtained through the first sensor.

[0014] In one possible design, a second sensor is installed at the air outlet of the second exhaust hood, and the controller is specifically used for:

[0015] The second exhaust volume is obtained through the second sensor.

[0016] In one possible design, the controller is specifically used for:

[0017] If the first exhaust volume is greater than the upper limit of the preset inflow volume range and the second exhaust volume is greater than the first exhaust volume, or if the first exhaust volume is less than the lower limit of the preset inflow volume range and the second exhaust volume is less than the first exhaust volume, then the width of the air inlet gap is increased.

[0018] If the first exhaust volume is less than the upper limit of the preset inflow volume range, and the second exhaust volume is greater than the first exhaust volume, then the width of the air inlet gap is reduced.

[0019] In one possible design, the aforementioned biosafety cabinet also includes a display, and the controller is specifically used for:

[0020] If the first exhaust volume is greater than the upper limit of the preset inflow volume range, and the second exhaust volume is greater than the first exhaust volume, the display will be controlled to issue an alarm, indicating that the inflow velocity is too high.

[0021] If the first exhaust volume is less than the upper limit of the preset inflow volume range, and the second exhaust volume is greater than the first exhaust volume, the display will be controlled to issue an alarm, indicating that the inflow velocity is too low.

[0022] If the first exhaust volume is less than the lower limit of the preset inflow volume range, and the second exhaust volume is less than the first exhaust volume, the display will be controlled to issue an alarm, indicating a malfunction in the exhaust system.

[0023] In one possible design, the exhaust system is connected to the second exhaust hood via a corrugated telescopic hose.

[0024] In one possible design, the adjustment assembly includes a drive member that moves the second exhaust hood up and down, and a guide rod parallel to the direction of movement of the second exhaust hood, with the second exhaust hood slidably connected to the guide rod.

[0025] In one possible design, the driving component includes a motor and a lead screw, the motor drives the lead screw to rotate, and the exhaust hood is provided with a connecting seat that is threadedly connected to the lead screw.

[0026] In one possible design, the motor is fixed to the cabinet, the lead screw and the guide rod pass through the second exhaust hood and are slidably connected to the second exhaust hood, and the second exhaust hood is provided with a bushing that is slidably connected to the guide rod.

[0027] In one possible design, the drive component is a telescopic electric cylinder, a hydraulic cylinder, or a pneumatic cylinder.

[0028] The beneficial effects of this application are as follows: The biosafety cabinet with adjustable exhaust volume provided by this application includes an exhaust hood, a controller, and an adjustment component. The exhaust hood includes an exhaust hood 1 and an exhaust hood 2 fitted outside the exhaust hood 1. The air inlet of the exhaust hood 1 is connected to the exhaust filter, and the air outlet is connected to the exhaust hood 2. An air inlet gap is formed between the exhaust hood 1 and the exhaust hood 2, connecting the outside world to the exhaust hood 2. The adjustment component is used to adjust the width of the air inlet gap. In use, the gas discharged from the exhaust filter passes through the exhaust hood 1 and the exhaust hood 2 in sequence and enters the exhaust system. At this time, the controller obtains the first exhaust volume entering the first air chamber from the exhaust filter and the second exhaust volume entering the exhaust system. Based on the first exhaust volume and the second exhaust volume, the controller controls the adjustment component to adjust the width of the air inlet gap. By adjusting the width of the air inlet gap, the amount of gas entering the exhaust hood 2 from the outside world is adjusted, thereby achieving the purpose of adjusting the exhaust volume of the biosafety cabinet without adversely affecting the descent velocity. At the same time, no modification to the exhaust system is required, making it relatively simple to implement. Attached Figure Description

[0029] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0030] Figure 1 This is a schematic diagram of the overall structure of the biosafety cabinet provided in the embodiments of this application;

[0031] Figure 2 A schematic diagram of the first usage state of the exhaust hood of the biosafety cabinet provided in the embodiments of this application;

[0032] Figure 3 A schematic diagram of the second usage state of the exhaust hood of the biosafety cabinet provided in the embodiments of this application;

[0033] Figure 4 A schematic diagram of the third usage state of the exhaust hood of the biosafety cabinet provided in the embodiments of this application;

[0034] Figure 5 A schematic diagram of the workflow of a biosafety cabinet is provided for embodiments of this application.

[0035] Figure label:

[0036] 100-Cabinet, 110-Exhaust filter, 120-First sensor, 200-Exhaust hood one, 300-Exhaust hood two, 400-Second sensor, 500-Air inlet gap, 600-Corrugated telescopic hose, 710-Lead screw, 720-Motor, 730-Guide rod, 740-Shaft sleeve.

[0037] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0039] The terms "first," "second," "third," "fourth," etc. (if present) in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of the invention described herein can be implemented, for example, in orders other than those illustrated or described herein.

[0040] In this application, the terms "exemplary" or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplary" or "for example" in this application should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of terms such as "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0041] For A2 biosafety cabinets, the inflow and exhaust air volumes must be equal, and the inflow air volume must be maintained within the nominal range during use. Related technologies typically control exhaust volume in two ways: one is by controlling the exhaust system, adjusting the exhaust system to control the exhaust volume, which requires adding various valves and sensors to the exhaust system, resulting in significant costs. The other method is to adjust the inflow velocity by regulating the fan speed or the opening degree of the exhaust valve. However, since the system resistance of the supply and exhaust systems in a biosafety cabinet is constant, this method causes changes in the downward velocity, resulting in the ratio of inflow velocity to downward velocity not falling within the nominal range, thus affecting the normal operation of the biosafety cabinet.

[0042] In this application, the exhaust hood includes an exhaust hood 1 and an exhaust hood 2 surrounding the outside of the exhaust hood 1. The exhaust hood 1 and the exhaust hood 2 are connected. The exhaust hood 1 is connected to the air outlet of the exhaust filter, and the exhaust hood 2 is connected to the exhaust system. An air inlet gap is formed between the exhaust hood 2 and the exhaust hood 1 to connect the outside world with the exhaust system. An adjustment component is also provided to adjust the width of the air inlet gap. The adjustment component is controlled by a controller. That is, during the operation of the biosafety cabinet, the controller obtains the first exhaust volume entering the exhaust hood 1 from the exhaust filter and the second exhaust volume entering the exhaust system. Based on the first and second exhaust volumes, the controller controls the adjustment component to adjust the width of the air inlet gap to adjust the amount of gas entering the exhaust system from the outside. This achieves the effect of adjusting the exhaust volume of the biosafety cabinet without affecting the downward air velocity.

[0043] The embodiments of this application will be described in detail below with reference to the accompanying drawings. It is understood that the following embodiments can be combined in any way, and similar designs of different embodiments may not be described again.

[0044] Please see Figure 1 As shown, the biosafety cabinet with adjustable exhaust volume provided in this application embodiment is basically the same as the existing biosafety cabinet, including a cabinet body 100, an exhaust filter 110, and an exhaust hood installed at the outlet end of the exhaust filter 110. The exhaust hood is connected to the exhaust system so that the exhaust system can be used to draw away the gas passing through the exhaust filter 110. Of course, it can be understood that the cabinet body 100 is equipped with an air box, a fan and an air supply filter. Driven by the fan, the indoor air and the original gas in the cabinet body 100 are mixed and enter the air box. Part of the gas in the air box enters the work area through the air supply filter, and the other part enters the exhaust system through the exhaust filter 110.

[0045] The difference in this embodiment is that the biosafety cabinet also includes a controller and an adjustment component. The exhaust hood includes an exhaust hood 200 and an exhaust hood 300 sleeved on the outside of the exhaust hood 200. The exhaust hood 200 forms a first air chamber that connects to the air inlet of the exhaust filter 110. One end of the exhaust hood 300 is connected to the exhaust system, and the other end is connected to the first air chamber. That is, the gas passing through the exhaust filter 110 passes through the exhaust hood 200 and the exhaust hood 300 in sequence, and finally enters the exhaust system. An air inlet gap 500 is formed between the exhaust hood 200 and the exhaust hood 300, connecting the inside and outside of the exhaust hood 300. The adjustment component is used to adjust the width of the air inlet gap 500. The controller is connected to the adjustment component and is mainly used to obtain the first exhaust volume entering the first air chamber from the exhaust filter 110 and the second exhaust volume entering the exhaust system. Based on the first exhaust volume and the second exhaust volume, the controller controls the adjustment component to adjust the width of the air inlet gap 500.

[0046] Specifically, the first exhaust volume is the exhaust volume of the biosafety cabinet, while the second exhaust volume is the total air volume currently being drawn by the exhaust system. The second exhaust volume is the sum of the air volume entering through the air inlet gap 500 and the first exhaust volume. During the operation of the biosafety cabinet, the controller continuously acquires the first and second exhaust volumes and compares the first exhaust volume with the nominal inflow air volume of the biosafety cabinet. When the first exhaust volume deviates from the nominal inflow air volume, the control adjustment component is activated to adjust the width of the air inlet gap 500 to adjust the air volume entering the exhaust hood 300 from the air inlet gap 500, thereby correcting the exhaust volume of the biosafety cabinet to match its nominal inflow air volume.

[0047] Simply modifying the structure of the exhaust hood to a combination of Exhaust Hood 1 (200) and Exhaust Hood 2 (300), and adding adjustment components and a controller, allows for automatic adjustment of the biosafety cabinet's exhaust volume. Compared to modifying the entire exhaust system, this significantly reduces installation difficulty and operating costs. Furthermore, compared to directly controlling the exhaust volume through dampers and fans, it does not affect the downward airflow velocity, effectively improving the biosafety cabinet's performance.

[0048] A first sensor 120 can be installed at the air outlet of the exhaust hood 200 to monitor the airflow leaving the exhaust hood 200. The gas inside the exhaust hood 200 originates from the gas discharged from the cabinet 100, meaning the controller can obtain the first exhaust volume through the exhaust hood 200. Of course, the first sensor 120 can also be placed in other locations, such as at the outlet of the exhaust filter 110. However, relatively speaking, installing it at the air outlet of the exhaust hood 200 does not require changing the structure of the cabinet 100, resulting in minimal structural changes. Furthermore, the cross-sectional area of ​​the air outlet of the exhaust hood 200 is relatively small, making measurement easier.

[0049] During the use of the biosafety cabinet, external gas enters the exhaust hood 2 300 through the air inlet gap 500 and mixes with the gas entering the exhaust hood 2 300 from the exhaust hood 1. The mixture then enters the exhaust system through the air outlet of the exhaust hood 2 300. Correspondingly, a second sensor 400 can be installed on the air outlet of the exhaust hood 2 300 to acquire the second exhaust volume. That is, the controller acquires the second exhaust volume through the second sensor 400.

[0050] Based on the above embodiments, the exhaust system and exhaust hood 2 300 can be connected via a corrugated telescopic hose 600. During the use of the biosafety cabinet, the adjustment of the air inlet gap 500 is mainly achieved by adjusting the height of exhaust hood 2 300 through an adjusting component, thereby changing the relative position between exhaust hood 2 300 and exhaust hood 1 200. As exhaust hood 2 300 moves up and down, the distance between it and the air inlet of the exhaust system also changes accordingly. Using the corrugated telescopic hose 600 allows the hose to automatically adjust its length to accommodate the up and down movement of exhaust hood 2 300, ensuring that the connection between exhaust hood 2 300 and the exhaust system remains unaffected.

[0051] As one specific embodiment of the adjustment component, the adjustment component includes a driving member that drives the second exhaust hood 300 to move up and down, and a guide rod 730 parallel to the moving direction of the second exhaust hood 300. The second exhaust hood 300 is slidably connected to the guide rod 730, that is, the guide rod 730 can effectively limit the moving trajectory of the exhaust hood.

[0052] The driving component can be one of a telescopic electric cylinder, a hydraulic cylinder, or a pneumatic cylinder. In this case, the driving component can be directly fixed to the cabinet 100 or other indoor installation structure, and the output end of the driving component is directly connected to the exhaust hood 2 300, so as to push the exhaust hood 2 300 to move up and down.

[0053] The driving component can also be configured as a combination of a motor 720 and a lead screw 710. Specifically, the output end of the motor 720 is connected to the lead screw 710 to drive the lead screw 710 to rotate, while the exhaust hood 300 is provided with a connecting seat that is threadedly connected to the lead screw 710. When it is necessary to adjust the width of the air inlet gap 500, the controller controls the motor 720 to start, and the motor 720 drives the lead screw 710 to rotate. At this time, the exhaust hood 300 is limited by the guide rod 730 and cannot rotate with the lead screw 710. That is, the connecting seat will not rotate with the lead screw 710, but will move up and down with the positive rotation of the lead screw 710, thereby driving the exhaust hood 300 to move up and down synchronously to adjust the width of the air inlet gap 500 more precisely.

[0054] Of course, the motor 720 needs to be located above or below the exhaust hood 300. In this case, it is best to fix the motor 720 directly to the cabinet 100. The length of the lead screw 710 only needs to meet the position adjustment requirements of the exhaust hood 300, and does not need to be too long. Alternatively, the guide rod 730 can also be directly fixed to the cabinet 100. In this case, both the lead screw 710 and the guide rod 730 can pass through the exhaust hood 300 and slide to connect with it, allowing the exhaust hood to move up and down under the drive of the lead screw 710. In addition, a bushing 740 that slides to connect with the guide rod 730 can be set on the exhaust hood 300 to improve the guiding effect of the guide rod 730 on the exhaust hood 300.

[0055] Please see Figure 5 As shown, based on the above embodiments, this example provides a method for adjusting the exhaust volume of a biosafety cabinet with adjustable exhaust volume, including the following steps:

[0056] S501. Obtain the first exhaust volume and the second exhaust volume.

[0057] Specifically, the controller is communicatively connected to the first sensor 120 and the second sensor 400, and obtains the first exhaust volume through the first sensor 120 and the second exhaust volume through the second sensor 400.

[0058] S502. Adjust the width of the air inlet gap 500 according to the first exhaust volume and the second exhaust volume:

[0059] If the first exhaust volume is greater than the upper limit of the preset inflow volume range and the second exhaust volume is greater than the first exhaust volume, or if the first exhaust volume is less than the lower limit of the preset inflow volume range and the second exhaust volume is less than the first exhaust volume, then increase the width of the air inlet gap by 500.

[0060] If the first exhaust volume is less than the upper limit of the preset inflow volume range, and the second exhaust volume is greater than the first exhaust volume, then the width of the air inlet gap is reduced by 500.

[0061] Specifically, the preset inflow air volume range is a range of air volume values ​​pre-set according to the parameters of the biosafety cabinet. Of course, it can also be a fixed air volume value. However, for biosafety cabinets, the inflow air volume is equal to the exhaust air volume, and the inflow air volume of a biosafety cabinet is basically a fixed range value. The preset inflow air volume range here needs to be within the nominal inflow air volume range of the biosafety cabinet. It can be the same as or slightly smaller than the nominal inflow air volume range. It can also be a fixed air volume value within the nominal inflow air volume range.

[0062] If the first exhaust volume is greater than the upper limit of the preset inflow volume range, and the second exhaust volume is greater than the first exhaust volume, it can be determined that the inflow volume of the biosafety cabinet is too large, exceeding the nominal inflow volume, which affects the normal operation of the biosafety cabinet. In this case, increasing the air inlet gap by 500 can increase the gas flow through the air inlet gap by 500. Since the exhaust volume of the exhaust system is constant, the exhaust volume of the biosafety cabinet can be effectively reduced, so that the inflow volume matches the nominal inflow volume of the biosafety cabinet.

[0063] If the first exhaust volume is less than the lower limit of the preset inflow volume range, and the second exhaust volume is less than the first exhaust volume, it indicates that the exhaust system has malfunctioned and the exhaust volume has dropped significantly, which is insufficient to meet the exhaust volume requirements of the biosafety cabinet. Some of the gas discharged from the biosafety cabinet has already been discharged through the air inlet gap 500. In this case, increasing the width of the air inlet gap 500 can increase the exhaust volume of the air inlet gap 500, thereby using the air inlet gap 500 to assist the biosafety cabinet in exhausting, and correcting the exhaust volume of the biosafety cabinet to a certain extent, reducing the impact.

[0064] If the first exhaust volume is less than the upper limit of the preset inflow volume range, and the second exhaust volume is greater than the first exhaust volume, it indicates that the exhaust volume of the biosafety cabinet is too small and the inflow volume is too small relative to the nominal inflow volume. In this case, reducing the width of the air inlet gap by 500 mm can reduce the amount of gas entering the exhaust system from the outside, thereby increasing the exhaust force of the biosafety cabinet and increasing the exhaust volume of the biosafety cabinet so that its inflow volume meets the nominal inflow volume.

[0065] For example, suppose a biosafety cabinet has a nominal inflow air volume of Q4, meaning the preset inflow air volume range is Q4, the first air volume is Q1, the second air volume is Q2, and the air volume entering the exhaust system from the inlet gap 500 is Q3. Reverse rotation of motor 720 increases the width of the inlet gap 500, and forward rotation of motor 720 decreases the width of the inlet gap 500. Then, under the following conditions, the controller will control the adjustment components to perform the following actions:

[0066] The first type: such as Figure 2 As shown, if Q2 > Q1, Q2 = Q1 + Q3, and Q1 and Q4 are in agreement, the biosafety cabinet is operating normally. The controller does not send commands to motor 720, and the biosafety cabinet can continue to operate in its original state.

[0067] The second type: such as Figure 3 As shown, Q1 > Q4, Q2 > Q1, Q2 = Q1 + Q3. The controller sends a command to the motor 720, causing the motor 720 to reverse and gradually increase the width of the air inlet gap 500 until Q2 > Q1, Q2 = Q1 + Q3, Q1 and Q4 match, and the controller stops the motor 720 from working.

[0068] The third type: such as Figure 4 As shown, Q1 < Q4, Q2 > Q1, Q2 = Q1 + Q3. The controller sends a command to the motor 720 to make the motor 720 rotate forward and gradually reduce the width of the air inlet gap 500 until Q2 > Q1, Q2 = Q1 + Q3, Q1 and Q4 match, and the controller stops the motor 720 from working.

[0069] The fourth scenario: Q1 < Q4, Q2 < Q1, Q2 ≠ Q1 + Q3. The controller sends a command to the motor 720, causing the motor 720 to reverse and gradually increase the width of the air inlet gap 500 until Q2 > Q1, Q2 = Q1 + Q3, Q1 and Q4 are in agreement, and the controller stops the motor 720 from working, or until the width of the air inlet gap 500 increases to the maximum value, and the controller stops the motor 720 from working.

[0070] Among the above situations, there is a case where the exhaust system malfunctions. In this case, staff need to repair the exhaust system. To remind staff, a buzzer or other alarm device can be installed. That is, when the exhaust system malfunctions or the exhaust volume does not meet the preset inflow air volume range, staff can be alerted so that they can carry out repairs in a timely manner.

[0071] Based on the above embodiments, a display can be set up for alarm purposes to alert staff. Specifically, the display can be communicatively connected to the controller, and the controller sends alarms through the display in the following manner:

[0072] When Q1 > Q4, Q2 > Q1, and Q2 = Q1 + Q3, the display will indicate that the inflow wind speed is too high to warn the staff. The warning will be canceled when Q2 > Q1, Q2 = Q1 + Q3, and Q1 and Q4 are equal.

[0073] When Q1 < Q4, Q2 > Q1, and Q2 = Q1 + Q3, the display will indicate that the inflow air velocity is too low to warn the staff. The warning will be canceled when Q2 > Q1, Q2 = Q1 + Q3, and Q1 and Q4 are equal.

[0074] When Q1 < Q4, Q2 < Q1, and Q2 ≠ Q1 + Q3, the display will indicate a ventilation system malfunction to warn the staff. The warning will be canceled after the ventilation system is repaired. The staff can cancel the warning manually, or the controller can automatically cancel the warning when it detects that Q2 > Q1, Q2 = Q1 + Q3, and Q1 and Q4 are equal.

[0075] Alternatively, the controller can be the same as the biosafety cabinet controller. It only requires inputting the computer software program corresponding to the above-mentioned exhaust volume adjustment method. When the controller executes the above-mentioned computer software program, it can perform the above-mentioned exhaust volume adjustment method.

[0076] Of course, the controller can also be set up separately. It includes at least a memory and a processor. The memory is used to store computer software programs, and the processor is used to execute the computer software programs stored in the memory to realize the above-mentioned exhaust volume adjustment method.

[0077] The processor can be a central processing unit, or other general-purpose processors, digital signal processors, application-specific integrated circuits, etc. The general-purpose processor can be a microprocessor, or any conventional processor. The steps of the method disclosed in this application can be directly manifested as being executed by a hardware processor, or being executed by a combination of hardware and software modules within the processor.

[0078] The memory may include high-speed RAM, and may also include non-volatile storage (NVM), such as at least one disk storage.

[0079] The technical solutions of this application have been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it is readily understood by those skilled in the art that the scope of protection of this application is obviously not limited to these specific embodiments. The above embodiments are only used to illustrate the technical solutions of this application and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A biosafety cabinet with adjustable exhaust volume, comprising a cabinet body, an exhaust filter, and an exhaust hood installed at the outlet end of the exhaust filter, the exhaust hood being connected with an exhaust system, characterized in that, The controller and the adjusting assembly are further included, the exhaust hood comprises an exhaust hood one and an exhaust hood two sleeved outside the exhaust hood one, a first air cavity is formed in the exhaust hood one and communicates with an air inlet of the exhaust filter, one end of the exhaust hood two is connected with the exhaust system and the other end communicates with the first air cavity, an air inlet gap is formed between the exhaust hood one and the exhaust hood two and communicates between the inside and the outside of the exhaust hood two, the adjusting assembly is used for adjusting the width of the air inlet gap, and the controller is used for: obtaining a first exhaust amount entering the first air cavity from the exhaust filter and a second exhaust amount entering the exhaust system; controlling the adjusting assembly to adjust the width of the air inlet gap according to the first exhaust amount and the second exhaust amount; The controller is specifically used for: if the first exhaust amount is greater than an upper limit value of a preset inflow air amount interval and the second exhaust amount is greater than the first exhaust amount, or if the first exhaust amount is less than a lower limit value of the preset inflow air amount interval and the second exhaust amount is less than the first exhaust amount, then the width of the air inlet gap is increased; if the first exhaust amount is less than the upper limit value of the preset inflow air amount interval and the second exhaust amount is greater than the first exhaust amount, then the width of the air inlet gap is reduced.

2. The variable exhaust biosafety cabinet of claim 1, wherein, A first sensor is arranged at an air outlet of the exhaust hood one, and the controller is specifically used for: obtaining the first exhaust amount through the first sensor.

3. The variable exhaust biosafety cabinet of claim 1, wherein, A second sensor is arranged at an air outlet of the exhaust hood two, and the controller is specifically used for: obtaining the second exhaust amount through the second sensor.

4. The variable exhaust biosafety cabinet of claim 1, wherein, A display is further included, and the controller is specifically used for: if the first exhaust amount is greater than an upper limit value of a preset inflow air amount interval and the second exhaust amount is greater than the first exhaust amount, then the display is controlled to alarm and prompt that the inflow air speed is too large; if the first exhaust amount is less than the upper limit value of the preset inflow air amount interval and the second exhaust amount is greater than the first exhaust amount, then the display is controlled to alarm and prompt that the inflow air speed is too small; if the first exhaust amount is less than a lower limit value of the preset inflow air amount interval and the second exhaust amount is less than the first exhaust amount, then the display is controlled to alarm and prompt that the exhaust system is faulty.

5. The variable exhaust biosafety cabinet of claim 1, wherein, The exhaust system and the exhaust hood two are connected through a corrugated flexible hose.

6. The variable exhaust biosafety cabinet of claim 1, wherein, The adjusting assembly comprises a driving member for driving the exhaust hood two to move up and down and a guide rod parallel to the moving direction of the exhaust hood two, and the exhaust hood two is slidably connected with the guide rod.

7. The variable exhaust biosafety cabinet of claim 6, wherein, The driving member comprises a motor and a screw rod, the motor drives the screw rod to rotate, and the exhaust hood two is provided with a connecting seat threadedly connected with the screw rod.

8. The variable exhaust biosafety cabinet of claim 7, wherein, The motor is fixed on the cabinet body, the screw rod and the guide rod penetrate through the exhaust hood two and are slidably connected with the exhaust hood two, and the exhaust hood two is provided with a shaft sleeve slidably connected with the guide rod.

9. The variable exhaust biosafety cabinet of claim 6, wherein, The driving member is a telescopic electric cylinder, a hydraulic cylinder or a pneumatic cylinder.

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