Method and system for pressurizing airflow of front window of biological safety cabinet

Abstract

The invention relates to the technical field of biosafety cabinets, in particular to a biosafety cabinet front window airflow pressurization system, when a biosafety cabinet runs, micro differential pressure sensors distributed in an air inlet channel and located under a front grating are arranged at equal intervals in the direction parallel to an operation cavity along the front grating and are in one-to-one correspondence with mounting assemblies of the front grating; and the pressure difference inside and outside the front grating at each component is monitored in real time. Once a certain micro differential pressure sensor monitors that the local differential pressure is abnormal, a signal is transmitted to the adjusting mechanism in the cavity of the corresponding transverse plate, and the adjusting mechanism and the micro differential pressure sensor form a closed-loop control system. The adjusting mechanism immediately drives the driven piston to drive the adjusting plate to change the extending amount, the adjusting plate is located in the cavity of the transverse plate and can extend out, and the local cross sectional area of the air inlet channel can be changed due to the extending amount change, so that the air inlet amount and the air inlet speed of the front grille at the position are adjusted, and airflow change caused by negative pressure abnormity is compensated. The negative pressure of each part of the front grille tends to be consistent, and finally a stable and uniform air flow barrier is formed.

Description

Technical Field

[0001] The present invention relates to the technical field of biosafety cabinets, and in particular to a method and system for pressurizing the airflow at the front window of a biosafety cabinet. Background Art

[0002] The biological safety cabinet mainly constructs an airflow barrier based on a negative pressure gradient through the specific structural coupling of the front grille and the front window operating port, thereby physically blocking pollutants such as bioaerosols.

[0003] The air velocity entering the front grille is closely related to the pressure differential between the inside and outside of the grille. This pressure differential is the primary driving force for airflow. The varying negative pressures at different parts of the grille result in uneven air velocity entering the grille, leading to turbulence. This turbulence disrupts the ideal airflow pattern within the biosafety cabinet, rendering the gas barrier, which relies on stable airflow, ineffective.

[0004] Therefore, there is an urgent need to develop a new control system with dynamic perception, precise compensation and multi-parameter coordination to ensure consistent negative pressure in all parts of the front grille, thereby forming a stable and uniform airflow barrier. Summary of the Invention

[0005] The object of the present invention is to provide a method and system for pressurizing the airflow at the front window of a biosafety cabinet, so as to solve the problems existing in the prior art.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0007] A system for boosting airflow at the front window of a biosafety cabinet comprises a front grille and an operating chamber. An air intake channel is provided below the front grille. The front grille is composed of a plurality of mounting components connected in series longitudinally. Each mounting component comprises a horizontally arranged horizontal plate. A vertical rod is fixed to the lower end surface of the horizontal plate. The vertical rod is fixed to the bottom wall of the air intake channel. Adjacent horizontal plates are connected by overlapping front and rear side walls to form a continuous arrangement structure.

[0008] It includes a micro-pressure differential sensor, which is arranged in the air intake passage and directly below the front grille. The number of micro-pressure differential sensors is consistent with the number of mounting components, and is evenly spaced along the front grille in a direction parallel to the operating cavity.

[0009] A cavity is provided inside the horizontal plate, and openings are provided on the left and right side walls of the cavity. An adjusting mechanism and a driven piston are provided in the cavity. An adjusting plate that can extend out of the cavity is fixed on the driven piston. The adjusting mechanism and the micro-pressure differential sensor constitute a closed-loop control system. When an abnormal local pressure difference is detected, the adjusting plate in the corresponding horizontal plate is driven to compensate for the extension amount.

[0010] When the biosafety cabinet is in operation, the micro-pressure differential sensors distributed in the air intake channel and located directly below the front grille are set at equal intervals along the front grille parallel to the operating chamber direction, corresponding one-to-one with the mounting components of the front grille, and monitor the pressure difference inside and outside the front grille at each component in real time. Once a micro-pressure differential sensor detects a local pressure difference abnormality, it transmits the signal to the adjustment mechanism in the corresponding cross-plate cavity. This mechanism and the micro-pressure differential sensor form a closed-loop control system. The adjustment mechanism then drives the driven piston, causing the adjustment plate to change its extension amount. Because the adjustment plate is located in the cross-plate cavity and can be extended, the change in its extension amount will change the local cross-sectional area of the air intake channel, thereby adjusting the air intake volume and air intake speed of the front grille at that part, compensating for the airflow changes caused by the negative pressure abnormality, making the negative pressure in each part of the front grille tend to be consistent, and ultimately forming a stable and uniform airflow barrier.

[0011] The system accurately monitors and adjusts the pressure difference of each part of the front grille in real time, effectively avoiding airflow disturbance and turbulence caused by uneven negative pressure, ensuring the stability of the airflow pattern in the biosafety cabinet, greatly enhancing the barrier capacity for pollutants such as bioaerosols, and providing reliable safety protection for experiments.

[0012] As a preference, an adjustment chamber is provided inside the vertical rod, the adjustment chamber is communicated with the cavity, a driving device and an active piston are provided in the adjustment chamber, the driving device can control the active piston to move up and down, and then drive the adjustment plate corresponding to the horizontal plate to compensate for the extension.

[0013] The regulating chamber is directly connected to the cavity, allowing the drive to quickly transmit the motion of the active piston to the driven piston, thereby rapidly changing the extension of the regulating plate. This direct mechanical connection significantly shortens the time between signal transmission and adjustment, enabling the system to more quickly respond to local pressure fluctuations and adjust the airflow in a timely manner. This effectively avoids airflow instability caused by slow response and ensures a stable airflow barrier is maintained within the biosafety cabinet.

[0014] Preferably, the driving device includes a micro linear stepping motor, which can be used to drive the active piston to move up and down.

[0015] The micro linear stepper motor offers extremely high position control accuracy, enabling precise control of the displacement of the active piston and, consequently, the extension of the adjustment plate. This allows the system to finely adjust the airflow across the front grille. Even the smallest pressure differentials can be precisely compensated by precisely varying the extension of the adjustment plate. This significantly improves the accuracy of airflow regulation, effectively maintaining a stable and uniform airflow pattern within the biosafety cabinet and enhancing the barrier to contaminants such as bioaerosols.

[0016] Preferably, a limiting ring for controlling the movement of the driven piston is provided at the opening of the cavity.

[0017] The fiber ring can effectively prevent the driven piston from falling out of the cavity.

[0018] Preferably, the bottom wall of the air inlet channel is provided with mounting sleeves distributed in an array; the lower end of the vertical rod is covered with an elastic bushing, and the vertical rod can be snapped into the corresponding mounting sleeve.

[0019] The array-distributed mounting sleeves provide clear mounting position identification for the vertical rods, and the elastic bushings are tightly snapped into the mounting sleeves, forming a stable connection between the vertical rods and the bottom wall of the air intake passage.

[0020] Preferably, the protruding end of the adjustment plate is provided with a serrated spoiler structure, and the serration spacing is 3-5mm.

[0021] The serrated edges create micro-vortex generators that, through periodic disturbances, break down the viscous substratum of the airflow within the boundary layer, breaking down large-scale vortices into micron-sized turbulent clusters. This design shifts the airflow separation point backward, reducing local pressure gradient fluctuations.

[0022] A method for pressurizing the airflow at the front window of a biosafety cabinet comprises the following steps:

[0023] Step 1: The air pressure in different areas below the front grille is collected by a micro-pressure differential sensor array, and the collected air pressure data is sent to the regulating mechanism;

[0024] Step 2: The regulating mechanism controls the movement of the slave piston in the area where the pressure is lower than the set value according to the air pressure data, thereby extending the regulating plate of the corresponding horizontal plate and reducing the air intake area of the corresponding area.

[0025] An array of micro-differential pressure sensors precisely collects air pressure in different areas and controls the extension of adjustment plates to precisely adjust the airflow pressure in each area of the front grille. This effectively avoids airflow turbulence caused by localized pressure imbalances, ensuring stable and uniform airflow within the biosafety cabinet, enhancing the barrier effect against pollutants such as bioaerosols, and providing reliable safety protection for experiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 Schematic diagram of the cross-section of the biosafety cabinet at the front grille in Example 1;

[0027] Figure 2 This is a schematic diagram of the structure of the installation components in Example 1;

[0028] Figure 3 Schematic diagram of the structure of the installation component in cross section in Example 1;

[0029] Figure 4 Schematic diagram of the structure of the installation assembly in Example 1 at the longitudinal section;

[0030] Figure 5 Schematic diagram of the structure of the driven piston and the adjustment plate in Example 1.

[0031] In the figure: 110, front grille; 120, operating chamber; 130, air intake channel; 140, mounting assembly; 1401, horizontal plate; 1402, vertical rod; 150, micro-pressure differential sensor; 1601, cavity; 1701, driven piston; 1702, adjustment plate; 1801, adjustment chamber; 1802, active piston; 1803, micro linear stepper motor; 190, mounting sleeve; 210, spoiler structure. DETAILED DESCRIPTION

[0032] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0033] Example 1

[0034] like Figures 1 to 5 As shown, the front window airflow booster system of the biosafety cabinet in this embodiment primarily comprises a front grille 110, an operating chamber 120, and associated ancillary structures. For clarity and simplicity, the biosafety cabinet's built-in glass windows and other conventional structural components are not shown in the figure; their configuration is consistent with conventional biosafety cabinets.

[0035] Below the front grille 110 lies an air intake duct 130, comprised of several mounting assemblies 140 arranged in series longitudinally. Each mounting assembly 140 comprises a horizontally arranged crossbar 1401, with vertical rods 1402 secured to their lower ends. These rods 1402, via elastic bushings wrapped around their lower ends, snap into mounting sleeves 190 arranged in an array on the bottom wall of the air intake duct 130. Adjacent crossbars 1401 are connected by overlapping front and rear sidewalls to form a continuous array. Within the air intake duct 130, directly below the front grille 110, micro-differential pressure sensors 150 are evenly spaced, matching the number of mounting assemblies 140.

[0036] Horizontal plate 1401 contains a cavity 1601 with open sidewalls. The cavity houses an adjustment mechanism and a slave piston 1701. Affixed to slave piston 1701 is an adjustment plate 1702 that extends out of cavity 1601. The extended end of adjustment plate 1702 is fitted with a serrated flow-disturbing structure 210 with a serration spacing of 3-5 mm. Vertical rod 1402 houses an adjustment cavity 1801, connected to cavity 1601. This cavity houses a miniature linear stepper motor 1803 as a drive mechanism and active piston 1802. A limit ring is also located at the opening of cavity 1601.

[0037] The specific operating principle is as follows: During the biosafety cabinet's operational testing, an array of micro-differential pressure sensors 150 collects real-time air pressure data from different areas below the front grille 110 and transmits it to the regulating mechanism. When the regulating mechanism receives data indicating a pressure below a set value, it controls the movement of the corresponding slave piston 1701. Specifically, a micro linear stepper motor 1803 acts as a drive to propel the active piston 1802 up and down within the regulating chamber 1801. Because the regulating chamber 1801 is connected to the cavity 1601 of the transverse plate 1401, the active piston 1802 drives the slave piston 1701, thereby extending the regulating plate 1702 and reducing the intake area in the corresponding area. The serrated spoiler structure 210 at the extended end of the regulating plate 1702 affects the airflow. Through periodic disturbances, it disrupts the viscous substratum within the boundary layer, breaking down large-scale vortices into micron-sized turbulent clusters. This shifts the separation point of the airflow, reduces local pressure gradient fluctuations, and increases the pressure in that area. At the same time, the limiting ring ensures that the driven piston 1701 moves normally within the cavity 1601 and prevents it from falling out. In this way, by precisely adjusting the air intake area of each area, the negative pressure in each part of the front grille 110 is consistent, forming a stable and uniform airflow barrier.

[0038] The above-mentioned setting can accurately collect air pressure data with the help of the micro-pressure differential sensor 150, and cooperate with the adjustment mechanism to accurately control the extension amount of the adjustment plate 1702, which can effectively adjust the airflow pressure in each area of the front grille 110, avoid airflow turbulence caused by local pressure unevenness, ensure stable and uniform airflow in the biosafety cabinet, greatly enhance the barrier ability to pollutants such as bioaerosols, and provide reliable and safe protection for experiments.

[0039] The regulating cavity 1801 of the vertical rod 1402 is directly connected to the cavity 1601 of the horizontal plate 1401. A micro linear stepper motor 1803 drives the active piston 1802, rapidly transmitting motion to the passive piston 1701. This rapidly changes the extension of the regulating plate 1702, enabling the system to quickly respond to local pressure anomalies and adjust airflow promptly, avoiding airflow instability caused by slow response. The micro linear stepper motor 1803 boasts high position control accuracy, precisely adjusting the extension of the regulating plate 1702. This allows for refined adjustments to airflow across the front grille 110, accurately compensating for even minor pressure anomalies and maintaining a stable and uniform airflow pattern.

[0040] The mounting sleeve 190 on the bottom wall of the air inlet channel 130 cooperates with the elastic bushing at the lower end of the vertical rod 1402 to securely connect the vertical rod 1402 to the bottom wall of the air inlet channel 130, ensuring the stability of the system structure and facilitating the installation and positioning of the vertical rod 1402. Furthermore, a retaining ring prevents the driven piston 1701 from dislodging, improving system operational reliability. The serrated flow-disrupting structure 210 at the protruding end of the adjustment plate 1702 optimizes airflow characteristics through a unique airflow perturbation method, reducing local pressure gradient fluctuations, further improving airflow stability and uniformity, and enhancing the overall performance of the biosafety cabinet.

Claims

1. A system for boosting airflow at the front window of a biosafety cabinet, comprising a front grille (110) and an operating chamber (120), wherein an air inlet channel (130) is provided below the front grille (110), and characterized in that: The front grille (110) is composed of a plurality of mounting assemblies (140) connected in series along the longitudinal direction. Each mounting assembly (140) includes a horizontally arranged transverse plate (1401). A vertical rod (1402) is fixed to the lower end surface of the transverse plate (1401). The vertical rod (1402) is fixed to the bottom wall of the air intake channel (130). Adjacent transverse plates (1401) are connected by overlapping front and rear side walls to form a continuous arrangement structure. It comprises a micro-pressure differential sensor (150) which is arranged in the air intake passage (130) and directly below the front grille (110). The number of the micro-pressure differential sensors (150) is the same as the number of the mounting components (140), and the sensors are arranged at equal intervals along the front grille (110) in a direction parallel to the operating chamber (120); A cavity (1601) is provided inside the transverse plate (1401), and openings are provided on the left and right side walls of the cavity (1601). An adjusting mechanism and a driven piston (1701) are provided inside the cavity (1601). An adjusting plate (1702) that can extend out of the cavity (1601) is fixed on the driven piston (1701). The adjusting mechanism and the micro-pressure differential sensor (150) form a closed-loop control system. When a local pressure difference abnormality is detected, the adjusting plate (1702) in the corresponding transverse plate (1401) is driven to compensate for the extension amount.

2. The system for boosting airflow at the front window of a biological safety cabinet according to claim 1, characterized in that: An adjusting chamber (1801) is provided inside the vertical rod (1402), and the adjusting chamber (1801) is connected to the cavity (1601). A driving device and an active piston (1802) are provided in the adjusting chamber (1801). The driving device can control the active piston (1802) to move up and down, thereby driving the adjusting plate (1702) corresponding to the horizontal plate (1401) to compensate for the extension.

3. The system for boosting airflow at the front window of a biological safety cabinet according to claim 2, characterized in that: The driving device includes a micro linear stepping motor (1803), which can be used to push the active piston (1802) to move up and down.

4. The system for boosting airflow at the front window of a biological safety cabinet according to claim 1, characterized in that: A limiting ring for controlling the movement of the driven piston (1701) is provided at the opening of the cavity (1601).

5. The system for boosting airflow at the front window of a biological safety cabinet according to claim 1, characterized in that: The bottom wall of the air inlet channel (130) is provided with mounting sleeves (190) distributed in an array, the lower end of the vertical rod (1402) is covered with an elastic bushing (200), and the vertical rod (1402) can be inserted into the corresponding mounting sleeve (190).

6. The system for boosting airflow at the front window of a biological safety cabinet according to claim 1, characterized in that: The protruding end of the adjustment plate (1702) is provided with a serrated flow-turbine structure (210), with a serration spacing of 3-5 mm.

7. A method for increasing the airflow pressure at the front window of a biosafety cabinet based on the system according to any one of claims 1 to 6, characterized in that: The following steps are included Step 1: collecting air pressure in different areas below the front grille (110) through an array of micro-differential pressure sensors (150), and sending the collected air pressure data to a regulating mechanism; Step 2: The regulating mechanism controls the movement of the slave piston (1701) in the area where the pressure is lower than the set value according to the air pressure data, thereby extending the regulating plate (1702) corresponding to the horizontal plate (1401) and reducing the air intake area of the corresponding area.

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