Constant negative pressure biological safety cabinet with speed regulated by double fans

Abstract

The utility model provides a constant negative pressure biological safety cabinet with double fans for speed regulation. The constant negative pressure biological safety cabinet comprises a box body, a working area, an air return cavity, an air supply fan, an air supply filter, an air exhaust fan, an air exhaust filter, a pressure sensor and a control system, the top of the box body is provided with an air inlet and an air outlet, the air outlet is communicated with the air return cavity, the pressure sensor is arranged in the working area, the box body is further provided with a display screen, and the pressure sensor, the display screen, the air supply fan and the air exhaust fan are all electrically connected with the control system. The pressure sensor monitors the negative pressure value of the working area relative to the external environment in real time and displays the negative pressure value through the display screen, the control system adjusts and controls the stability of the negative pressure value of the working area, and it is guaranteed that no leakage risk exists during equipment operation. The cleanliness of a working area is high, air is cleaned, one-way downward airflow is formed, the laminar flow state without vortex is achieved, and the risk of cross contamination is avoided.

Description

Technical Field

[0001] This utility model relates to the field of biosafety cabinet technology, and in particular to a constant negative pressure biosafety cabinet with dual fan speed regulation. Background Technology

[0002] A Class 3 biosafety cabinet is one of the highest levels of biosafety equipment, primarily used for handling highly pathogenic or potentially fatal pathogens, providing comprehensive protection for personnel, experimental samples, and the environment. Its main applications include the pharmaceutical industry, the medical device industry, and biosafety laboratories.

[0003] However, existing biosafety cabinets have poor airflow stability and uniformity in the working area, which can generate turbulence and easily cause cross-contamination in experiments. Existing Class III biosafety cabinets generally adopt a negative pressure design. When the usage environment changes, such as increased resistance of HEPA filters, temperature changes, or insufficient air supply in the laboratory, the equipment cannot guarantee the real-time negative pressure, thus posing a risk of leakage. Summary of the Invention

[0004] To address the aforementioned problems, this invention provides a constant negative pressure biosafety cabinet with dual-fan speed regulation.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A constant negative pressure biosafety cabinet with dual-fan speed regulation includes a cabinet, a work area, a return air chamber, a supply fan, a supply air filter, an exhaust fan, an exhaust air filter, a pressure sensor, and a control system.

[0007] The top of the housing is provided with an air inlet and an air outlet, the air outlet being connected to the return air chamber. The working area is located inside the housing. The air supply fan is installed at the air inlet, and the air supply filter is installed below the air supply fan. The working area is located below the air supply filter, and a workbench is installed at the bottom of the working area. The workbench has air holes that connect to the return air chamber. The exhaust fan and the exhaust filter are installed at the air outlet. The pressure sensor is located in the working area, and the pressure sensor, air supply fan, and exhaust fan are all electrically connected to the control system.

[0008] Furthermore, the air supply fan is installed on the top of the housing, and a static pressure box is provided inside the housing. The static pressure box includes an air inlet end and an air outlet end. The air inlet end is connected to the air inlet port, and the air supply filter is installed on the air outlet end. A flow equalization plate is installed on the top of the working area.

[0009] Furthermore, a baffle is fixedly installed inside the housing, which divides the inner cavity of the housing into a front cavity and a rear cavity. The working area is located in the front cavity, and the workbench is located at the bottom of the front cavity. The side of the workbench facing the baffle is connected to the lower end of the baffle. The bottom of the workbench and the inner bottom of the housing form a lower cavity, and the lower cavity is connected to the rear cavity to form the return air cavity.

[0010] Furthermore, a mounting plate is provided at the connection between the lower cavity and the rear cavity. The mounting plate is provided with a mounting groove. The bottom of the mounting groove is provided with a vent. A first exhaust fan is installed at the vent. A first exhaust filter is installed in the mounting groove. The first exhaust fan is electrically connected to the control system.

[0011] Furthermore, the air holes are arranged around the workbench in an array.

[0012] Furthermore, a transparent window is provided on the side wall of the box on the front of the work area, and gloves are installed in the transparent window. There are at least two gloves. A double-door pass-through window is installed on the side of the box of the work area.

[0013] Furthermore, a liquid collection tank is provided below the workbench. The liquid collection tank is a box with an upward opening, including a bottom surface and four sides. The lower end of the baffle is fixed on the side facing the baffle, and the remaining three sides are respectively connected to the inner side wall of the box. A ventilation hole is provided in the middle of the bottom surface, and a flow stop plate is provided around the ventilation hole.

[0014] Furthermore, the ventilation hole is a rectangular hole, the baffle plate is a rectangular frame, the lower end of the rectangular frame is fixed to the bottom surface, and the ventilation hole is located inside the baffle plate.

[0015] Furthermore, the supply air filter, the exhaust air filter, and the first exhaust air filter are all high-efficiency filters / ultra-high-efficiency filters.

[0016] Furthermore, the bottom of the box is equipped with casters.

[0017] Compared with the prior art, the beneficial effects of this utility model are as follows: (1) This utility model monitors the negative pressure value of the working area relative to the external environment in real time through a pressure sensor and displays it on the screen. The control system judges the current pressure and the set pressure based on the pressure monitored by the pressure sensor, and automatically adjusts the speed of the supply fan, exhaust fan and the first exhaust fan to stabilize the negative pressure value of the working area, ensuring that there is no risk of leakage when the equipment is running. Constant negative pressure in the working area reduces the risk of experimental leakage. The negative pressure is adjustable. The control system regulates the fan speed, eliminating the need for manual adjustment and simplifying the operation process. (2) When this utility model is in use, the airflow enters the box through the air inlet, passes through the supply air filter and forms a uniform downward airflow from the top of the working area, flowing through the working area to form a clean area. After passing through the working area, the airflow continues to enter the return air chamber through the air hole on the workbench, and is discharged from the exhaust fan outlet after being filtered by the exhaust filter. This ensures a high degree of cleanliness in the working area, clean air, and forms a unidirectional downward airflow, a laminar flow state without vortices, avoiding the risk of cross-contamination. Attached Figure Description

[0018] Figure 1 This is a front view of a constant negative pressure biosafety cabinet with dual-fan speed regulation according to this utility model;

[0019] Figure 2 This is a structural schematic diagram of a constant negative pressure biosafety cabinet with dual-fan speed regulation according to the present invention;

[0020] Figure 3 This is a schematic diagram of the workbench of a constant negative pressure biosafety cabinet with dual-fan speed regulation according to the present invention.

[0021] Figure 4 This is a schematic diagram of the liquid collection tank of a constant negative pressure biosafety cabinet with dual-fan speed regulation according to this utility model. Detailed Implementation

[0022] To provide a better understanding of the purpose, structure, features, and functions of this utility model, detailed descriptions are provided below with reference to specific embodiments.

[0023] Please refer to the reference. Figure 1 , Figure 2 , Figure 3 and Figure 4 A constant negative pressure biosafety cabinet with dual-fan speed regulation according to an embodiment of the present invention includes a cabinet body 100, a working area 200, a return air chamber 300, a supply air fan 400, a supply air filter 500, an exhaust air fan 600, an exhaust air filter 700, a pressure sensor 800, and a control system.

[0024] The top of the housing 100 is provided with an air inlet 110 and an air outlet 120. The air outlet 120 is connected to the return air chamber 300. The working area 200 is located inside the housing 100. The air supply fan 400 is installed at the air inlet 110. The air supply filter 500 is installed below the air supply fan 400. The working area 200 is located below the air supply filter 500. A workbench 210 is installed at the bottom of the working area 200. The workbench 210 has air holes 211 that connect to the return air chamber 300. The exhaust fan 600 and the exhaust filter 700 are installed at the air outlet 120. A pressure sensor 800 is located in the working area 200. The pressure sensor 800 is electrically connected to the control system. The control system is also connected to the air supply fan 400 and the exhaust fan 600. The control system is also connected to a power supply device to supply power to the equipment. The housing 100 is also equipped with a display screen 130, which is electrically connected to the control system. The display screen 130 can show the current pressure, allowing for real-time pressure monitoring and prevention of leakage.

[0025] During use, airflow enters the housing 100 through the air inlet 110, passes through the air supply filter 500, and forms a uniform downward airflow from the top of the work area 200, flowing through the work area to create a clean zone. After passing through the work area 200, the airflow continues through the air holes 211 on the surface of the workbench 210 into the return air chamber 300, and after being filtered by the exhaust filter 700, it is discharged from the exhaust vent by the exhaust fan 600. This ensures a high level of cleanliness in the work area, providing clean air and forming a unidirectional downward airflow in a laminar flow state without turbulence, thus avoiding the risk of cross-contamination.

[0026] The air supply fan 400 is installed on the top of the housing 100. A static pressure box 140 is provided inside the housing 100. The static pressure box 140 includes an air inlet 141 and an air outlet 142. The air inlet 141 is connected to the air inlet 110, and the air outlet 142 is equipped with the air supply filter 500. A flow equalization plate 220 is installed on the top of the working area 200. This ensures that after the gas enters from the air inlet 110, the stability and uniformity of the airflow are improved. The static pressure box 140 reduces the wind speed, converting some dynamic pressure into static pressure, thereby increasing the air supply distance and uniformly lowering the airflow. This ensures that the gas passes evenly through the air supply filter 500, resulting in good filtration and ensuring a uniform downward airflow at the top of the working area 200, thus forming a clean area.

[0027] A baffle 150 is fixedly installed inside the housing 100, dividing the inner cavity of the housing 100 into a front cavity 101 and a rear cavity 102. The working area 200 is located in the front cavity 101, and the workbench 210 is located at the bottom of the front cavity 101. The side of the workbench 210 facing the baffle 150 is connected to the lower end of the baffle 150. The bottom of the workbench 210 and the inner bottom of the housing 100 form a lower cavity 103. The lower cavity 103 is connected to the rear cavity 102 to form the return air cavity 300. The design of baffle 150 improves the strength of the housing 100 and prevents deformation of the housing 100. The baffle 150 separates the housing from the workbench 210 to form a return air cavity 300, so that the airflow enters the return air cavity downward through the air hole 211. This ensures that the airflow enters the housing 100 through the air inlet 110 and passes through the air supply filter 500 to form a uniform downward airflow from the top of the work area. The airflow then flows through the work area 200 to form a clean area.

[0028] A mounting plate 160 is provided at the connection between the lower cavity 103 and the rear cavity 102. The mounting plate 160 has a mounting groove 161, and the bottom of the mounting groove 161 has an air hole 162. A first exhaust fan 900 is installed at the air hole 162, and a first exhaust filter 163 is installed inside the mounting groove 161. The first exhaust fan 900 is electrically connected to the control system, facilitating the control system to adjust the speed of the first exhaust fan 900. The supply air filter 500, the exhaust air filter 700, and the first exhaust filter 163 are all high-efficiency or ultra-high-efficiency filters. This improves the filtration effect, ensures the cleanliness of the equipment's working area, and prevents external contamination. This device, through the design of exhaust fan 600 and first exhaust fan 900, ensures that the airflow entering from the air inlet 110 flows into the lower chamber 103 through the air holes on the workbench 210. In the lower chamber 103, the airflow is conveyed by the first exhaust fan 900 and passes through the first exhaust filter 163 before entering the rear chamber 102. It is then conveyed by the exhaust fan 600 located in the rear chamber 102, filtered by the exhaust filter 700, and flows out through the air outlet 120. The system ensures a decreasing airflow velocity in work area 200, creating a descending laminar flow and establishing a Class 100 cleanroom environment. The first exhaust fan 900 maintains negative pressure in work area 200 and lower chamber 103 relative to the external environment, between supply air filter 500 and first exhaust filter 163. The exhaust fan 600 maintains negative pressure in the rear chamber 102 relative to the external environment, between first exhaust filter 163 and exhaust filter 700. Due to the relatively high resistance from the two exhaust HEPA filters, the dual exhaust fans better guarantee the exhaust volume. This also better overcomes the resistance of the exhaust filters and increases the diversity of exhaust fan selection.

[0029] During operation, the required pressure is set via display screen 130. Different negative pressure levels can be set for different usage scenarios to achieve energy-saving effects. During operation, pressure sensor 800 monitors the negative pressure value of the working area 200 relative to the external environment in real time and displays it on display screen 130. The control system determines the difference between the current pressure and the set pressure based on the pressure monitored by pressure sensor 800. If the current pressure is greater than the set pressure, the speed of exhaust fan 600 and first exhaust fan 900 is increased, or the speed of supply fan 400 is decreased, to reach the set pressure. If the current pressure is less than the set pressure, the speed of exhaust fan 600 and first exhaust fan 900 is decreased, or the speed of supply fan 400 is increased, to reach the set pressure, thus ensuring the stability of the negative pressure in working area 200. Maintaining a constant negative pressure in working area 200 reduces the risk of experimental leakage. The negative pressure is adjustable via display screen. The control system regulates the fan speed, eliminating the need for manual adjustment and simplifying the operation process.

[0030] The air vents 211 are arranged around the workbench 210 to ensure that the descending air can cover the entire surface of the workbench 210, thus ensuring the cleanliness of the entire working area. The array of multiple air vents 211 ensures good air permeability and uniform airflow, allowing air to enter the return air chamber 300 and form a uniform descending airflow from the top of the working area, thus creating a clean zone.

[0031] A transparent window 230 is provided on the side wall of the front enclosure of the work area 200. At least two gloves 240 are fitted into the transparent window 230. A double-door pass-through window 250 is installed on the side of the enclosure of the work area 200. The transparent window 230 is achieved by installing glass, which is pressed against the front main body of the enclosure 100 through a frame. Two gloves 240 are fitted onto the glass. Operators can use the gloves 240 for operation. A double-door pass-through window 250 is provided on the right side of the equipment for passing items. This facilitates operation and testing, prevents contamination inside the equipment, improves the cleanliness of the equipment interior, and avoids contamination affecting the test.

[0032] A liquid collection tank 260 is provided below the workbench 210. The liquid collection tank 260 is an upward-opening box, including a bottom surface 261 and four side surfaces 262. The lower end of the baffle 150 is fixed to the side facing the baffle 150, and the remaining three side surfaces 262 are respectively connected to the inner side walls of the box body 100. A ventilation hole 263 is provided in the middle of the bottom surface 261, and a flow stop plate 264 is provided around the ventilation hole 263. The liquid collection tank 260 is designed to collect liquids that overflow during the experiment. The overflowing liquid will flow down from the vents on the workbench surface or the gaps around it into the liquid collection tank, thus achieving collection. The ventilation hole 263 ensures that the liquid collection tank 260 does not obstruct the airflow, facilitating airflow. The flow stop plate 264 blocks the liquid flow, preventing the liquid in the liquid collection tank from falling into the return air chamber from the ventilation hole 263, avoiding contamination. A water valve is also fixed on the tank 100. The water valve is connected to the bottom of the collection tank through a pipe to discharge the waste liquid in the collection tank.

[0033] The ventilation hole 263 is a rectangular hole, and the flow stop plate 264 is a rectangular frame. The lower end of the rectangular frame 264 is fixed to the bottom surface 261, and the ventilation hole 263 is located inside the flow stop plate 264. The structure is aesthetically pleasing. The flow stop plate 264 not only prevents liquid from flowing down the collection tank but also increases the strength of the bottom surface 261, preventing breakage at the ventilation hole 263 and extending its service life.

[0034] The bottom of the housing 100 is equipped with casters 170. This facilitates equipment movement and improves equipment flexibility.

[0035] This utility model has been described by the above-described embodiments; however, these embodiments are merely examples for implementing this utility model. It must be noted that the disclosed embodiments do not limit the scope of this utility model. Conversely, any modifications and refinements made without departing from the spirit and scope of this utility model are within the scope of patent protection of this utility model.

Claims

1. A constant negative pressure biosafety cabinet with dual-fan speed regulation, characterized in that: It includes the enclosure, working area, return air chamber, supply air fan, supply air filter, exhaust air fan, exhaust air filter, pressure sensor, and control system; The top of the housing is provided with an air inlet and an air outlet, the air outlet being connected to the return air chamber. The working area is located inside the housing. The air supply fan is installed at the air inlet, and the air supply filter is installed below the air supply fan. The working area is located below the air supply filter, and a workbench is installed at the bottom of the working area. The workbench has air holes that connect to the return air chamber. The exhaust fan and the exhaust filter are installed at the air outlet. The pressure sensor is located in the working area, and the pressure sensor, air supply fan, and exhaust fan are all electrically connected to the control system.

2. The constant negative pressure biosafety cabinet with dual-fan speed regulation as described in claim 1, characterized in that: The air supply fan is installed on the top of the housing. A static pressure box is provided inside the housing. The static pressure box includes an air inlet and an air outlet. The air inlet is connected to the air inlet port. The air supply filter is installed on the air outlet. A flow equalization plate is installed on the top of the working area.

3. The constant negative pressure biosafety cabinet with dual-fan speed regulation as described in claim 1, characterized in that: A baffle is fixedly installed inside the housing, dividing the inner cavity of the housing into a front cavity and a rear cavity. The working area is located in the front cavity, and the workbench is located at the bottom of the front cavity. The side of the workbench facing the baffle is connected to the lower end of the baffle. The bottom of the workbench and the inner bottom of the housing form a lower cavity, and the lower cavity is connected to the rear cavity to form the return air cavity.

4. The constant negative pressure biosafety cabinet with dual-fan speed regulation as described in claim 3, characterized in that: A mounting plate is provided at the connection between the lower cavity and the rear cavity. The mounting plate has a mounting groove, and the bottom of the mounting groove has a vent. A first exhaust fan is installed at the vent. A first exhaust filter is installed in the mounting groove. The first exhaust fan is electrically connected to the control system.

5. The constant negative pressure biosafety cabinet with dual-fan speed regulation as described in claim 1, characterized in that: The air holes are arranged around the workbench in an array.

6. The constant negative pressure biosafety cabinet with dual-fan speed regulation as described in claim 1, characterized in that: The front side wall of the work area is provided with a transparent window, and gloves are installed in the transparent window. There are at least two gloves. The side wall of the work area is equipped with a double-door pass-through window.

7. The constant negative pressure biosafety cabinet with dual-fan speed regulation as described in claim 3, characterized in that: Below the workbench is a liquid collection tank, which is an upward-opening box containing a bottom and four sides. The lower end of the baffle is fixed to the side facing the baffle, and the remaining three sides are respectively connected to the inner sidewall of the box. A ventilation hole is provided in the middle of the bottom, and a flow stop plate is provided around the ventilation hole.

8. The constant negative pressure biosafety cabinet with dual-fan speed regulation as described in claim 7, characterized in that: The ventilation hole is a rectangular hole, the baffle is a rectangular frame, the lower end of the rectangular frame is fixed to the bottom surface, and the ventilation hole is located inside the baffle.

9. The constant negative pressure biosafety cabinet with dual-fan speed regulation as described in claim 4, characterized in that: The supply air filter, exhaust air filter, and first exhaust air filter are all high-efficiency filters / ultra-high-efficiency filters.

10. The constant negative pressure biosafety cabinet with dual-fan speed regulation as described in claim 1, characterized in that: The bottom of the box is equipped with casters.

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