Biological safety cabinet and method for measuring inflow air speed thereof

Abstract

The present application belongs to the technical field of biological safety cabinets, and particularly relates to a biological safety cabinet and a flow-in wind speed measurement method thereof, and aims to solve the problem of inaccurate flow-in wind speed measurement of the biological safety cabinet. The flow-in wind speed measurement method comprises the following steps: obtaining an exhaust area S out and a face wind speed u of an exhaust port; obtaining an exhaust wind speed V out of the exhaust port, and obtaining a correction coefficient K between the face wind speed u and the exhaust wind speed V out , wherein K = face wind speed u / exhaust wind speed V out ; obtaining an inlet area S in of an inlet port; calculating a flow-in wind speed V in , and the flow-in wind speed V in satisfies V in = K x (S out x V out ) / S in . The flow-in wind speed measurement method can accurately measure the flow-in wind speed V in of the biological safety cabinet, and improve the operation safety.

Description

Technical Field

[0001] This invention belongs to the field of biosafety cabinet technology, specifically relating to a biosafety cabinet and a method for measuring its inflow air velocity. Background Technology

[0002] A biosafety cabinet is a device designed to protect the operator, the laboratory environment, and the experimental materials from exposure to infectious aerosols and splashes that may be generated during the handling of infectious experimental materials such as primary cultures, bacterial and viral strains, and diagnostic specimens.

[0003] Currently, biosafety cabinets use a centrifugal fan to draw in negative pressure airflow from the front operating window to protect personnel. Biosafety cabinets have strict requirements on the flow rate of the airflow entering through the front window and the flow rate of the airflow descending inside the cabinet; these rates cannot be too low or too high, otherwise they will fail to protect personnel and experimental samples. Therefore, it is necessary to measure the inflow air velocity inside the biosafety cabinet.

[0004] In existing technologies, wind speed sensors are typically installed at the exhaust vent of biosafety cabinets. The wind speed measured by the wind speed sensor is then used to calculate the inflow wind speed. This results in inaccurate measurements of the inflow wind speed, which in turn affects the operational safety of the biosafety cabinet. Summary of the Invention

[0005] In order to solve the above-mentioned problems in the prior art, namely, to solve the problem that the inflow wind speed measured by the wind speed sensor is not accurate enough, thus affecting the operational safety of the biosafety cabinet.

[0006] The first aspect of this invention provides a method for measuring the inflow velocity of a biosafety cabinet, comprising the following steps:

[0007] Obtain the exhaust area S of the exhaust vent out and face wind speed u;

[0008] Obtain the exhaust air velocity V at the exhaust vent. out And obtain the face velocity u of the exhaust vent and the exhaust velocity V. out The correction factor K is given between the two values, where K = face velocity u / exhaust velocity V. out ;

[0009] Obtain the air inlet area S in ;

[0010] Calculate the inflow wind speed V in And the inflow wind speed V in Satisfy: V in =K×(S) out ×V out ) / S in .

[0011] In the preferred embodiment of the above-mentioned inflow wind speed measurement method, the air inlet is configured to have a fixed length in a first direction and an adjustable width in a second direction; a distance sensor connected to the control unit is provided at the air inlet, and the distance sensor is configured to measure the width of the air inlet.

[0012] The air inlet area S of the air inlet is obtained. in The steps include:

[0013] The length of the air inlet in the first direction is obtained and assigned to the control unit;

[0014] The width of the air inlet in the second direction is obtained in real time using the ranging sensor.

[0015] The control unit calculates the air intake area S based on the length and width of the air intake. in .

[0016] In the preferred embodiment of the above-mentioned inflow wind speed measurement method, the step of obtaining the face wind speed u at the exhaust outlet includes:

[0017] The exhaust air volume Q of the exhaust port is obtained using a face shield. out And calculate the exhaust air volume Q. out With exhaust area S out The ratio of the two values ​​is used to obtain the exhaust velocity V. out .

[0018] In the preferred embodiment of the above-mentioned method for measuring inflow wind speed, the inflow wind speed V is calculated... in In the steps, the exhaust air volume Q out Equal to the air intake volume Q of the air inlet in .

[0019] In the preferred embodiment of the above-mentioned inflow wind speed measurement method, the biosafety cabinet includes a wind speed sensor that is signal-connected to the control unit, and the wind speed sensor is arranged at the exhaust port.

[0020] Obtain the exhaust air velocity V at the exhaust vent. out The steps include:

[0021] The exhaust wind speed V at the exhaust vent is obtained in real time using the wind speed sensor. out And the exhaust wind speed V out The data is transmitted to the control unit.

[0022] A second aspect of this invention provides a biosafety cabinet, including a cabinet body and an inflow velocity measuring device. The cabinet body is provided with an exhaust vent, a glass door, and a rectangular front window operating opening. The glass door is installed at the front window operating opening, and the glass door and the front window operating opening form an air inlet with a variable opening area. The inflow velocity measuring device includes a wind speed sensor and a distance sensor that are signal-connected to a control unit. The distance sensor is located at the lower edge of the glass door and is configured to measure the width of the air inlet along a second direction and transmit the measurement to the control unit. The wind speed sensor is located at the exhaust vent and is used to measure the exhaust wind speed V. out The control unit is configured to calculate the air inlet area S based on the length and width of the air inlet. in And calculate the inflow wind speed V in And the inflow wind speed V in Satisfy: V in =K×(S) out ×V out ) / S in Where K represents the face velocity u at the exhaust vent and the exhaust velocity V. out The correction factor between them, K = face velocity u / exhaust velocity V out S in For air intake area, S out This refers to the exhaust area of ​​the exhaust vent.

[0023] In the preferred embodiment of the above-mentioned biosafety cabinet, the detection end of the ranging sensor is flush with the lower edge of the glass door, and the ranging sensor is opposite to the lower frame of the front window operating port.

[0024] In the preferred embodiment of the above-described biosafety cabinet, the biosafety cabinet further includes a display screen connected to the control unit via a signal; the display screen is configured to display the measured inflow velocity V. in .

[0025] In the preferred embodiment of the above-mentioned biosafety cabinet, the front window operating port is located on the front side of the cabinet body, and the exhaust vent is located on the top surface of the cabinet body; the exhaust vent is rectangular, and the detection end of the exhaust sensor extends into the exhaust vent.

[0026] In the preferred embodiment of the above-mentioned biosafety cabinet, the biosafety cabinet further includes an air collecting hood adapted to the exhaust port; the air collecting hood is detachably installed to the exhaust port, and the air collecting hood is configured to measure the face velocity u of the exhaust port.

[0027] Compared with related technologies, the biosafety cabinet and its inflow velocity measurement method provided by the present invention have the following advantages:

[0028] The biosafety cabinet and inflow velocity measurement method provided by this invention, in the inflow velocity measurement method of the biosafety cabinet, obtains the face velocity u at the exhaust vent and the exhaust velocity V. out The correction factor K is used to adjust the obtained exhaust velocity V. out Correction is performed to overcome the limitations of measuring the exhaust wind speed V at a single point using a wind speed sensor. out There is a measurement error between the surface wind speed u and the surface wind speed u.

[0029] This setup allows for the conversion of the real-time exhaust velocity into a more accurate measured face velocity u, which can then be further calculated based on the intake air volume Q. in With exhaust air volume Q out Similarly, obtain accurate inflow wind speed V in To improve its operational safety.

[0030] In addition to the technical problems solved by the embodiments of this disclosure described above, the technical features constituting the technical solutions, and the beneficial effects brought about by the technical features of these technical solutions, other technical problems that can be solved by the biosafety cabinet and its inflow wind speed measurement method provided by the embodiments of this invention, other technical features included in the technical solutions, and the beneficial effects brought about by these technical features will be further described in detail in the specific embodiments. Attached Figure Description

[0031] A preferred embodiment of the biosafety cabinet and its inflow velocity measurement method of the present invention will now be described with reference to the accompanying drawings. The drawings are as follows:

[0032] Figure 1 This is a front view of the biosafety cabinet provided in Embodiment 1 of the present invention;

[0033] Figure 2 This is a top view of the biosafety cabinet provided in Embodiment 1 of the present invention;

[0034] Figure 3 This is a cross-sectional view of the biosafety cabinet provided in Embodiment 1 of the present invention;

[0035] Figure 4 A flowchart illustrating the inflow wind speed measurement method provided in Embodiment 2 of the present invention. Figure 1 .

[0036] Explanation of reference numerals in the attached figures:

[0037] 10-Cabinet;

[0038] 11-Front window control opening; 12-Exhaust vent;

[0039] 20 - Wind speed sensor;

[0040] 30 - Sliding door;

[0041] 40 - Distance sensor;

[0042] 100 - Biosafety Cabinet. Detailed Implementation

[0043] As described in the background section, a wind speed sensor is installed at the exhaust vent of a biosafety cabinet, and the wind speed measured by the sensor is used as the inflow wind speed. However, there is a technical problem: the measured inflow wind speed is not accurate enough, thus affecting the operational safety of the biosafety cabinet. The inventors discovered that this problem arises because the aforementioned wind speed sensor is usually located at the edge of the exhaust vent, and the sensor's detection end extends to the edge of the exhaust vent. The wind speed sensor can only perform single-point detection, and the exhaust wind speed varies at different locations compared to the entire exhaust vent; for example, the exhaust wind speed near the edge of the exhaust vent is usually lower than the exhaust wind speed near the center of the exhaust vent. Therefore, there is a measurement error between the exhaust wind speed detected by the aforementioned wind speed sensor and the actual face wind speed u at the exhaust vent. Consequently, based on the principle that the exhaust air volume Qout is the same as the inflow air volume Qin, the calculated inflow wind speed is inaccurate.

[0044] To address the aforementioned technical problems, the present invention provides a method for measuring the inflow velocity of a biosafety cabinet by acquiring the face velocity u and the exhaust velocity V at the exhaust vent. out The ratio correction coefficient K is used to adjust the obtained exhaust velocity V. out Correction is performed to overcome the limitations of measuring the exhaust wind speed V at a single point using a wind speed sensor. out The measurement error between the face velocity u and the inlet air volume Q is a limitation, and the goal is to obtain an accurate face velocity u in real time and further adjust the measurement based on the inlet air volume Q. in With exhaust air volume Q out Similarly, obtain accurate inflow wind speed V in To improve its operational safety.

[0045] To make the above-mentioned objectives, features, and advantages of the embodiments of the present invention more apparent and understandable, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0046] Example 1

[0047] like Figures 1 to 3As shown, the biosafety cabinet 100 provided in this embodiment of the invention is a device designed to protect the operator, laboratory environment and experimental materials from exposure to infectious aerosols and splashes that may be generated during the operation of primary cultures, bacterial and viral strains and diagnostic specimens.

[0048] The biosafety cabinet 100 draws in negative pressure airflow generated inside the cabinet through the front window operating port 11 to protect the safety of the operator. It has strict requirements on the flow rate of the airflow flowing in through the front window and the flow rate of the airflow descending inside the cabinet. It cannot be too low or too high, otherwise it will affect the safe operation of the biosafety cabinet 100.

[0049] Therefore, the biosafety cabinet 100 provided in this embodiment of the invention includes a cabinet body 10 and an inflow velocity measuring device disposed on the cabinet body 10. The inflow velocity measuring device is used to measure the inflow velocity inside the biosafety cabinet 100 in real time, so as to improve the operational safety of the biosafety cabinet 100 and protect the experimental personnel and experimental samples.

[0050] To facilitate a detailed description of the embodiments of the present invention, the coordinate system in the accompanying drawings will be explained first, wherein the X-axis is the first direction, which corresponds to the length direction of the cabinet 10, the Z-axis is the second direction, which corresponds to the height direction of the cabinet 10, and the Y-axis corresponds to the width direction of the cabinet 10.

[0051] Specifically, the cabinet 10 in this embodiment of the invention includes a front window operation port 11, an exhaust port 12, and a glass door. The glass door is installed on the front window operation port 11 and can move relative to the front window operation port 11 in a second direction. When the glass door is configured to move in the second direction, it can close the front window operation port 11, or the lower edge of the glass door and the lower frame of the front window operation port 11 have a certain gap, that is, the glass door and the front window operation port 11 form an air inlet.

[0052] For example, the cabinet 10 includes a front side and a top side, and a front window operation opening 11 is disposed on the front side of the cabinet 10. The front window operation opening 11 can be a regular shape, such as a circle or a rectangle. Preferably, in order to facilitate the calculation of the air inlet area based on the position of the glass door, the front window operation opening 11 in this embodiment is a rectangular opening, and the front window operation opening 11 has a certain length L1 in the first direction and a certain width L2 in the second direction.

[0053] Since the glass door is installed inside the front window operating opening 11, when calculating the air intake area, the length L1 of the front window operating opening 11 is used as the length of the air intake in the first direction, and this value is fixed. As the glass door moves, the width of the air intake in the second direction changes, so it is necessary to calculate the width of the air intake in real time.

[0054] Therefore, the inflow wind speed measuring device provided in this embodiment of the invention includes a distance sensor 40 and a wind speed sensor 20, and the distance sensor 40 and the wind speed sensor 20 are respectively signal-connected to the control unit. It should be noted that this control unit can be part of the inflow wind speed measuring device or a component of the biosafety cabinet 100; preferably, the above-mentioned control unit is a component of the biosafety cabinet 100, that is, the inflow wind speed measuring device shares a control unit with other units that need to be controlled, and this embodiment of the invention does not limit this.

[0055] In this embodiment of the invention, the distance sensor 40 is disposed on the lower edge of the sliding door 30, and the distance sensor 40 is capable of measuring the distance between the lower edge of the sliding door 30 and the lower frame of the front window operating opening 11, and transmitting the measurement result to the control unit. That is, the distance sensor 40 is configured to measure the width of the air inlet in the second direction and transmit the width of the air inlet to the control unit. Further, the control unit obtains the air inlet area based on the width and length of the air inlet.

[0056] Furthermore, the wind speed sensor 20 is installed at the exhaust vent 12, and the detection end of the wind speed sensor 20 extends into the exhaust vent 12 to facilitate the detection of the exhaust wind speed V at the exhaust vent 12. out The wind speed sensor 20 is connected to the control unit, therefore the wind speed sensor 20 can detect and transmit the exhaust wind speed V. out The data is transmitted to the control unit.

[0057] For example, the exhaust vent 12 is located on the top surface of the cabinet 10. The exhaust vent 12 is rectangular. The wind speed sensor 20 can be located at one edge of the exhaust vent 12, and the detection end of the wind speed sensor 20 extends into the exhaust vent 12 so that the wind speed sensor 20 can obtain the exhaust wind speed V. out .

[0058] In this embodiment of the invention, the control unit is configured to determine the air inlet area S based on the air inlet area. in Calculate the inflow wind speed V in And the inflow wind speed V in Satisfy: V in =K×(S) out ×V out ) / S in Wherein, the correction coefficient K is the ratio of the face velocity u at exhaust vent 12 to the exhaust velocity V. out The ratio between them, S in For air intake area, S out The exhaust area S of exhaust vent 12 out .

[0059] It should be noted that the above formula for calculating the inflow velocity Vin is based on the operating conditions of the biosafety cabinet 100, according to the exhaust volume Q. out Equal to the air intake volume Q at the air inlet in The algorithm formula for the inflow wind speed is further calculated, and the algorithm formula for the inflow wind speed needs to be embedded in the control unit.

[0060] The face velocity u and exhaust velocity V of the above-mentioned exhaust vent 12 out The correction coefficient K value needs to be determined after the wind speed sensor 20 is installed. The face wind speed u of the exhaust port 12 can be obtained using the airflow hood; that is, the exhaust wind speed V of the wind speed sensor 20 at this time can be obtained under the current conditions. out Then, the correction coefficient K value is obtained, which is usually a constant. The exhaust velocity V is then established using the correction coefficient. out The relationship between the wind speed u and the face wind speed.

[0061] Furthermore, the control unit obtains the air intake area S in And exhaust area S out Then, according to the formula, the inflow wind speed V in =K×(S) out ×V out ) / S in Calculate the current inflow wind speed V in Thus, in the air intake area S in Even under real-time changes, the inflow wind speed V can still be accurately obtained. in .

[0062] Compared with the prior art, the biosafety cabinet 100 provided in this embodiment of the invention obtains a correction coefficient K for the ratio between the face velocity u of the exhaust vent 12 and the exhaust velocity Vout, and uses the correction coefficient K to adjust the obtained exhaust velocity Vout. out Correction is performed to overcome the inaccurate exhaust wind speed V measured by the single-point wind speed sensor 20. out The measurement error between the face velocity u and the inlet air volume Q is a limitation, and the goal is to obtain an accurate face velocity u in real time and further adjust the measurement based on the inlet air volume Q. in With exhaust air volume Q out Similarly, accurate inflow wind speed is obtained to improve operational safety.

[0063] Based on the above embodiments, in this embodiment of the invention, the detection end of the distance sensor 40 is flush with the lower edge of the glass door, and the detection end of the distance sensor 40 is opposite to the lower frame of the front window operating opening 11. This arrangement, with the detection end of the distance sensor 40 flush with the lower edge of the glass door, facilitates the measurement of the width of the air inlet in the second direction and avoids interference between the detection end of the distance sensor 40 and the lower frame of the front window operating opening 11 when the glass door is closed.

[0064] For example, the ranging sensor 40 is a laser ranging sensor 40, which emits ranging light that can illuminate the surface of the lower frame of the front window operating opening 11. The ranging sensor 40 converts the distance between the lower edge of the glass door and the lower frame of the front window operating opening 11 into an electrical signal and sends it to the control unit, so that the control unit can obtain the width of the air inlet in the second direction.

[0065] Furthermore, in this embodiment of the invention, the biosafety cabinet 100 may be equipped with two ranging sensors 40. Along the first direction, the two ranging sensors 40 are respectively disposed on both sides of the glass door. The two ranging sensors 40 are respectively signal-connected to the control unit, and the detection end of each ranging sensor 40 is flush with the lower edge of the glass door. With this arrangement, this embodiment of the invention provides ranging sensors 40 on both sides of the glass door to improve the reliability of obtaining the width of the air inlet.

[0066] Based on the above embodiments, the biosafety cabinet 100 provided in this embodiment of the invention further includes a display screen that is signal-connected to the control unit. The display screen can be located on the front side of the cabinet body 10, and the display screen is configured to display the current inflow air velocity V of the biosafety cabinet 100. in This setup allows researchers to determine whether the inflow velocity of the biosafety cabinet 100 meets safety standards, thereby enhancing the reliability of protection for researchers.

[0067] Understandably, the control unit may also be set with a preset inflow velocity under the composite safety conditions of the biosafety cabinet 100. When the detected inflow velocity is less than the preset inflow velocity, the control unit will issue a warning signal, which may cause the warning sign displayed on the screen to light up. Alternatively, the biosafety cabinet 100 may be equipped with other alarm devices, such as warning lights.

[0068] Furthermore, the biosafety cabinet 100 provided in this embodiment of the invention may be configured with an air collecting hood as needed. The air collecting hood is used to obtain the face velocity u of the exhaust port 12. The air collecting hood can be detachably installed to the exhaust port 12, and the air inlet of the air collecting hood cooperates with the exhaust port 12 of the cabinet body 10 so that the air inlet of the air collecting hood and the exhaust port 12 of the cabinet body 10 are sealed together to improve the accuracy of obtaining the face velocity u of the exhaust port 12.

[0069] Example 2

[0070] like Figure 4 As shown, this embodiment of the invention provides a method for measuring the inflow velocity of a biosafety cabinet 100, including the following steps:

[0071] Step S100: Obtain the exhaust area S of exhaust vent 12 out And the face wind speed u.

[0072] Specifically, before measuring the inflow velocity of the biosafety cabinet 100, the face velocity u of the biosafety cabinet 100 needs to be obtained so that the exhaust velocity V obtained by the wind speed sensor 20 can be used for subsequent measurement. out Given the face velocity u, calculate the correction factor K for both; and based on the correction factor K and the exhaust area S... out Calculate the inflow wind speed V in The exhaust area S mentioned above out The face wind speed u and the correction coefficient K are stored in the control unit.

[0073] For example, the exhaust area S of exhaust vent 12 out Typically, these are fixed values. Therefore, measuring tools are used to measure the length of the exhaust vent 12 in the first direction and the width in the second direction, and the exhaust area S is then calculated. out and the exhaust area S out Assign the value to the control unit.

[0074] Furthermore, the face velocity u of the exhaust vent 12 can be measured using an airflow hood, which is detachably installed on the exhaust vent 12 of the cabinet 10. When it is necessary to measure the face velocity u of the exhaust vent 12, the airflow hood is sealed and connected to the exhaust vent 12. After the measurement is completed, the airflow hood can be removed from the exhaust vent 12.

[0075] For example, the exhaust air volume Q of the exhaust vent 12 is obtained using a face shield. out， And based on the exhaust air volume Q out With exhaust area S out The ratio of the two values ​​is used to obtain the exhaust velocity V. out .

[0076] Step S200: Obtain the exhaust air velocity V at exhaust vent 12 out And obtain the face velocity u and exhaust velocity V of exhaust vent 12. out The correction factor K is given by: K = face velocity u / exhaust velocity V. out .

[0077] Specifically, the wind speed sensor 20 installed at the exhaust vent 12 is used to collect the exhaust wind speed V at the exhaust vent 12 in real time. out And the exhaust wind speed V out The data is transmitted to the control unit. The control unit then uses the acquired face velocity u and exhaust velocity V from the exhaust vent 12. out Calculate the correction factor K, where the correction factor K is equal to the ratio of the face velocity u to the exhaust velocity V. out The ratio between them is calculated, and the correction coefficient is stored in the control unit.

[0078] Step S300: Obtain the air inlet area S of the air inlet. in .

[0079] Specifically, the air inlet area S of the biosafety cabinet 100 in this embodiment of the invention is... in The size of the air inlet formed by the glass door and the front window operating opening 11 varies depending on the position of the glass door. Therefore, the air inlet area S needs to be adjusted in real time. in Take measurements.

[0080] For example, in this embodiment of the invention, a glass door is movably installed in the front window operating opening 11. The width between the lower edge of the glass door and the lower frame of the front window operating opening 11 is variable, meaning the width of the air inlet in the second direction is variable. Since the length of the air inlet in the first direction is fixed, this length is measured and assigned to the control unit. Therefore, only the width of the air inlet in the second direction needs to be measured.

[0081] For example, in this embodiment, a distance sensor 40 is provided at the bottom of the glass door. The distance sensor 40 is signal-connected to the control unit. The distance sensor 40 obtains the width of the air inlet in the second direction in real time and transmits it to the control unit. The control unit calculates the current air inlet area S based on the length and width of the air inlet. in .

[0082] Step S400: Calculate the inflow wind speed V in And the inflow wind speed V in Satisfy: V in =K×(S) out ×V out ) / S in .

[0083] Specifically, based on the exhaust volume Q of the biosafety cabinet 100 during operation... out Equal to the air intake volume Q at the air inlet in That is, exhaust area S out × Face wind speed u = Inflow wind speed S in ×Air inlet area S in Furthermore, the inflow wind speed S in = (exhaust area S) out ×face wind speed u) / air inlet area S in . Furthermore, in the embodiments of the present invention, the face wind speed u and the exhaust wind speed V out The correction factor K = face velocity u / exhaust velocity V out Then the face wind speed u = K × exhaust wind speed V out . Therefore, the inflow wind speed V in =K×(S) out ×V out ) / S inThat is, the control unit is based on the correction coefficient K and the exhaust area S. out Exhaust area S in And exhaust wind speed V out Calculate the inflow wind speed V in .

[0084] Compared with related technologies, the biosafety cabinet 100 and the inflow velocity measurement method provided in this embodiment of the invention, in the inflow velocity measurement method of the biosafety cabinet 100, obtains a correction coefficient K between the face velocity u of the exhaust vent 12 and the exhaust velocity Vout, and uses the correction coefficient K to adjust the obtained exhaust velocity Vout. out Correction is performed to overcome the inaccurate exhaust wind speed V measured by the single-point wind speed sensor 20. out There is a measurement error between the surface wind speed u and the surface wind speed u.

[0085] This setup allows for the conversion of the real-time exhaust velocity into a more accurate measured face velocity u, and further, based on the assumption that the intake and exhaust air volumes are the same, an accurate inflow velocity V can be obtained. in To improve its operational safety.

[0086] The various embodiments or implementation methods described in this specification are presented in a progressive manner. Each embodiment focuses on the differences from other embodiments, and the same or similar parts between the embodiments can be referred to each other.

[0087] It should be noted that the terms "one embodiment," "embodiment," "exemplary embodiment," "some embodiments," etc., mentioned in the specification indicate that the described embodiment may include a specific feature, structure, or characteristic, but not every embodiment necessarily includes that specific feature, structure, or characteristic. Furthermore, such phrases do not necessarily refer to the same embodiment. Moreover, when a specific feature, structure, or characteristic is described in connection with an embodiment, implementing such a feature, structure, or characteristic in conjunction with other embodiments, whether explicitly described or not, is within the knowledge scope of those skilled in the art.

[0088] Generally speaking, terms should be understood at least in part by their use in context. For example, at least in part by context, the term "one or more" as used in the text can be used to describe any feature, structure, or characteristic of the singular meaning, or a combination of features, structures, or characteristics of the plural meaning. Similarly, at least in part by context, terms such as "a" or "the" can also be understood to convey either singular or plural usage.

[0089] It should be readily understood that the terms “on,” “above,” and “on top of” in this disclosure should be interpreted in the broadest possible sense, such that “on” means not only “directly on something” but also “on something” with an intermediate feature or layer therebetween, and that “above” or “on top of” means not only “on top of something” but also “on top of something” without an intermediate feature or layer therebetween (i.e., directly on something).

[0090] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention 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; and 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 the present invention.

Claims

1. A method for measuring the inflow velocity of a biosafety cabinet, characterized in that, Includes the following steps: Obtain the exhaust area of ​​the exhaust vent The exhaust air volume of the exhaust port is obtained using the air collection hood. And calculate the exhaust air volume. With exhaust area The ratio of the surface wind speed u is used to obtain the face wind speed u. Obtain the exhaust air velocity of the exhaust vent. And obtain the face velocity u of the exhaust vent and the exhaust velocity. The correction coefficient K between them, where ; The air inlet is configured to have a fixed length in a first direction and an adjustable width in a second direction; a distance sensor connected to the control unit is provided at the air inlet, and the distance sensor is configured to measure the width of the air inlet; The length of the air inlet in the first direction is obtained and assigned to the control unit; The width of the air inlet in the second direction is obtained in real time using the ranging sensor. The control unit calculates the air intake area based on the length and width of the air intake. ; Calculate the inflow wind speed And the inflow wind speed satisfy: ； The biosafety cabinet is equipped with the air collection hood. The biosafety cabinet includes a cabinet body. The air collection hood is detachably installed to the exhaust port. The air inlet of the air collection hood cooperates with the exhaust port to make the air inlet of the air collection hood and the exhaust port sealed together. The cabinet is equipped with an exhaust vent, a glass door, and a rectangular front window operating opening. The glass door is installed at the front window operating opening, and the glass door and the front window operating opening together form an air inlet with a variable opening area. The distance sensor is disposed on the lower edge of the glass door, with its detection end flush with the lower edge of the glass door, and is opposite to the lower frame of the front window operating opening. 。 2. The method for measuring inflow wind speed according to claim 1, characterized in that, The calculation of inflow wind speed In the steps, the exhaust air volume t Equal to the air intake volume of the air inlet .

3. The method for measuring inflow wind speed according to claim 1, characterized in that, The biosafety cabinet includes a wind speed sensor that is signal-connected to the control unit, and the wind speed sensor is located at the exhaust vent. Obtain the exhaust air velocity of the exhaust vent. The steps include: The exhaust air velocity at the exhaust vent is obtained in real time using the aforementioned wind speed sensor. and the exhaust wind speed The data is transmitted to the control unit.

4. A biosafety cabinet, characterized in that, Includes the cabinet and the inflow velocity measuring device; The cabinet is equipped with an exhaust vent, a glass door, and a rectangular front window operating opening. The glass door is installed at the front window operating opening, and the glass door and the front window operating opening together form an air inlet with a variable opening area. The inflow wind speed measuring device includes a wind speed sensor and a distance sensor that are connected to the control unit via signals. The distance sensor is located at the lower edge of the glass door and is configured to measure the width of the air inlet along the second direction and transmit the measurement to the control unit. The detection end of the distance sensor is flush with the lower edge of the glass door and the distance sensor is opposite to the lower frame of the front window operating opening. The wind speed sensor is installed at the exhaust outlet and is used to measure the exhaust wind speed. The control unit is configured to calculate the air inlet area S based on the length and width of the air inlet. in And calculate the inflow wind speed And the inflow wind speed satisfy: ， Where K represents the face velocity u at the exhaust vent and the exhaust velocity. Correction coefficients between , For air intake area, The exhaust area of ​​the exhaust vent; The biosafety cabinet also includes an air collection hood adapted to the exhaust vent; The air collecting hood is detachably installed to the exhaust port. The air collecting hood is configured to measure the face velocity u of the exhaust port. The air inlet of the air collecting hood is sealed to the exhaust port.

5. The biosafety cabinet according to claim 4, characterized in that, The biosafety cabinet also includes a display screen that is signal-connected to the control unit; The display screen is configured to display the measured inflow wind speed. .

6. The biosafety cabinet according to claim 4, characterized in that, The front window operating port is located on the front side of the cabinet, and the exhaust vent is located on the top surface of the cabinet; The exhaust vent is rectangular, and the detection end of the exhaust sensor extends into the exhaust vent.

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