Laboratory waste gas purification ventilation cabinet

Abstract

The invention discloses a laboratory waste gas purification fume cupboard, and belongs to the technical field of fume cups.The laboratory waste gas purification fume cupboard comprises a cabinet, a workbench is installed at the top end of the cabinet, an auxiliary ventilation mechanism is arranged at the top end of the workbench, the auxiliary ventilation mechanism comprises a suction fan fixedly installed at the top end of the workbench, and supporting pipes are arranged on the two sides of the workbench; and the input end of the suction fan communicates with a filtering part for filtering waste gas, a gas collection cylinder is rotationally installed on the surface, close to the interior of the workbench, of the supporting pipe, the suction fan communicates with the interior of the gas collection cylinder through an air inlet assembly, and a gas suction assembly is arranged on the outer surface of the gas collection cylinder. The air inlet amount of the auxiliary air suction assembly can be dynamically adjusted according to the actual air pressure in the cabinet by combining accurate control of the air pressure valve on opening and closing of the ventilation pipeline, so that the air inlet amount is matched with the air draft amount of the fan in real time, the negative pressure value is stabilized in a safe interval, and the waste gas leakage risk is further eradicated.

Description

Technical Field

[0001] This invention relates to the field of fume hood technology, and in particular to a laboratory exhaust gas purification fume hood. Background Technology

[0002] In experiments in chemistry, biology, and medicine, waste gases containing harmful gases, volatile organic compounds, corrosive substances, or toxic dust are often generated. Direct discharge of these gases into the laboratory environment or the atmosphere not only pollutes the air but also seriously harms the health of laboratory personnel and may even lead to safety accidents. Therefore, fume hoods, as core safety equipment in laboratories, are widely used for waste gas collection and discharge. Their core function is to create a stable negative pressure environment to quickly collect and treat the waste gases generated during experiments, ensuring the safety of experimental operations and the cleanliness of the environment. Existing laboratory fume hoods rely on a single main ventilation mechanism for waste gas collection, limiting the suction range to a specific area inside the fume hood. Dead zones, especially in the gaps of the glass doors and corners inside the hood, easily form, leading to the leakage of harmful waste gases into the laboratory environment. This fails to achieve comprehensive waste gas capture. Furthermore, during long-term use, the ventilation inlets are easily blocked by dust and droplets generated during experiments, affecting suction efficiency. Blocked vents can also cause waste gas to flow away, thus affecting the experimental environment. Summary of the Invention

[0003] The purpose of this invention is to provide a laboratory exhaust gas purification fume hood to solve the problems mentioned in the background art, such as the air inlet being easily blocked by dust, mist droplets and other particles generated in experiments, which affects the air intake efficiency, and the blocked air inlet easily causing exhaust gas to flow, thus affecting the experimental environment.

[0004] To achieve the above objectives, the present invention provides the following technical solution: a laboratory exhaust gas purification fume hood, comprising a cabinet, a workbench mounted on the top of the cabinet, an auxiliary ventilation mechanism mounted on the top of the workbench, the auxiliary ventilation mechanism comprising a suction fan fixedly mounted on the top of the workbench, support pipes mounted on both sides of the workbench, and a filter component for filtering exhaust gas connected to the input end of the suction fan, a gas collecting cylinder rotatably mounted on the surface of the support pipe near the inside of the workbench, the suction fan communicating with the inside of the gas collecting cylinder through an air inlet assembly, a suction assembly mounted on the outer surface of the gas collecting cylinder, the suction assembly comprising multiple nozzles connected to and mounted on the outer surface of the gas collecting cylinder, multiple suction holes opened on the outer surface of the nozzles, a permeable plate fixedly mounted inside the nozzles, a sealing plate for sealing the permeable plate on the surface of the nozzles away from the suction holes, and multiple elastic ropes fixedly mounted between the sealing plate and the inner wall of the nozzles.

[0005] As a preferred embodiment of the present invention, the nozzle is provided with a honeycomb plate for preliminary filtration, and a sedimentation tank is provided at the bottom end of the nozzle near the honeycomb plate.

[0006] As a preferred embodiment of the present invention, the outer surface of the workbench is provided with a swing assembly. The swing assembly includes a motor fixedly installed on the outer surface of the workbench, a circular plate fixedly installed on the output shaft of the motor, a circular rod fixedly installed on the top end of the circular plate, a third gear rotatably installed on the top end of the air collecting cylinder, a first gear and a second gear rotatably installed on the top end of the support tube, and the first gear and the third gear meshing through the second gear. A rack is slidably installed on the top end of the support tube, and the rack meshes with the first gear. A sliding plate is fixedly installed on one end of the rack, and the circular rod is slidably installed inside the sliding plate.

[0007] As a preferred embodiment of the present invention, a carbon rod for initial adsorption of odors is rotatably installed inside the gas collecting cylinder, and multiple channels are opened on the outer surface of the carbon rod. A toothed ring is fixedly installed at the top of the carbon rod, and a fourth gear is rotatably installed at the top of the carbon rod, and the toothed ring and the third gear mesh through the fourth gear.

[0008] As a preferred embodiment of the present invention, an arc-shaped cleaning plate is fixedly installed on the inner wall of the workbench near the nozzle, and a cleaning sponge for cleaning the nozzle surface is fixedly installed on the surface of the cleaning plate near the nozzle.

[0009] As a preferred embodiment of the present invention, the outer surface of the workbench is provided with a limiting component, the limiting component includes a mounting plate fixedly installed on the outer surface of the support tube, the inside of the workbench is provided with a groove, a cylinder is fixedly installed inside the groove, a movable plate is slidably installed inside the cylinder, a spring is fixedly installed between the movable plate and the inner wall of the cylinder, a slide rod is fixedly installed on the outer surface of the movable plate, and the mounting plate is threadedly connected to the slide rod by a screw.

[0010] As a preferred embodiment of the present invention, the air intake assembly includes a ventilation duct connected between the air collection cylinder and the suction fan. A plurality of first magnetic blocks are fixedly installed inside the ventilation duct. An auxiliary air cushion for protecting the duct is attached to the inner wall of the ventilation duct. A plurality of second magnetic blocks are fixedly installed on the outer surface of the auxiliary air cushion. The first magnetic blocks and the second magnetic blocks are magnetically connected. One end of the auxiliary air cushion is connected to an air inlet. The air inlet is sealed and fixed by a piston block.

[0011] As a preferred embodiment of the present invention, the outer surface of the ventilation duct is provided with a plurality of air pressure valves, and the air pressure valves control the opening and closing of the ventilation duct by means of the air pressure inside the workbench.

[0012] As a preferred embodiment of the present invention, the inner wall of the workbench is provided with a main ventilation mechanism, the main ventilation mechanism includes a plurality of main air intakes opened on the workbench near the filter component, the input end of the suction fan is connected to the main air intakes through the filter component, and a guide plate for air suction guidance is fixedly installed on the inner wall of the workbench near the main air intakes.

[0013] As a preferred embodiment of the present invention, the outer surface of the workbench is provided with a glass sliding door for closing the workbench, and a control board is provided at the top of the workbench. The control board is electrically connected to the glass sliding door and the suction fan through a built-in power supply.

[0014] Compared with the prior art, the beneficial effects of the present invention are: This invention utilizes the coordinated operation of the main and auxiliary ventilation mechanisms, combined with precise control of the ventilation duct opening and closing via pressure valves, to dynamically adjust the air intake of the auxiliary ventilation mechanism based on the actual air pressure inside the cabinet. When the negative pressure inside the cabinet is low (insufficient exhaust volume / excessive exhaust gas), the air intake of the nozzles on both sides automatically decreases, prioritizing the integrity of the airflow curtain at the main intake port and preventing exhaust gas leakage. When the negative pressure inside the cabinet is too high (excessive exhaust volume / insufficient air intake), the air intake valves of the nozzles on both sides automatically open wider, quickly replenishing the laboratory's normal atmospheric pressure air, ensuring real-time matching between the air intake and the fan's exhaust volume, stabilizing the negative pressure value within a safe range, and further eliminating the risk of exhaust gas leakage.

[0015] This invention utilizes the driving force of a swing assembly. A motor, through a gear transmission structure, drives the air collection cylinder and nozzles to rotate at multiple angles, overcoming the limitations of a fixed air intake and comprehensively covering blind spots prone to air stagnation, such as the ends of glass sliding doors and the corners of cabinets. Simultaneously, the distributed design of multiple nozzles, combined with the large-area layout of the air intake holes, further enhances the comprehensiveness of air capture, effectively preventing localized air accumulation and significantly improving air collection efficiency.

[0016] In the waste gas collection process, the honeycomb panel inside the nozzle can perform preliminary filtration of particulate matter such as dust and droplets in the waste gas, while the sedimentation tank and carbon rod can collect and preliminarily adsorb the filtered impurities. Finally, the waste gas is discharged after deep filtration by the filtration components, forming a multi-stage treatment process of "preliminary filtration - adsorption and deodorization - deep purification". At the same time, the sealing plate, together with the elastic rope, can automatically seal the nozzle when the air pressure inside the cabinet is too high, avoiding secondary pollution caused by waste gas diversion and ensuring the purification effect.

[0017] During the rotation of the nozzle driven by the swing component, the arc-shaped cleaning plate and surface cleaning sponge on the inner wall of the workbench can simultaneously wipe the outer surface of the nozzle, automatically removing adsorbed dust and impurities and preventing the air intake hole from being blocked. At the same time, the combination design of the honeycomb plate and sedimentation tank inside the nozzle can reduce the entry of particulate matter into the ventilation duct, reduce the probability of duct blockage, and reduce the frequency of manual cleaning and consumable replacement.

[0018] The present invention uses an auxiliary air cushion on the inner wall of a ventilation duct to be fixed by magnetic adsorption. After being inflated, the auxiliary air cushion adheres to the inner wall of the ventilation duct, thereby protecting the ventilation duct body. This not only prevents damage to the inside of the ventilation duct and allows for stable exhaust gas discharge over a long period of time, but also makes the auxiliary air cushion easy to replace and use. It effectively buffers airflow impact, reduces duct vibration and wear, and improves the operational stability of the equipment.

[0019] This invention utilizes the cooperation of a spring and a screw to securely limit the position of the support tube and the air collection cylinder, preventing deviation during swinging and ensuring transmission accuracy. Simultaneously, the suction mechanisms on both sides of the worktable can be easily disassembled and installed, allowing for cleaning and replacement of the suction devices on both sides, ensuring stable ventilation in the fume hood. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a side view of the structure of the present invention; Figure 3 This is a schematic diagram of the swing mechanism structure of the present invention; Figure 4 This is a schematic diagram of the carbon rod structure of the present invention; Figure 5 This is a schematic diagram of the cross-sectional structure of the nozzle of the present invention; Figure 6 This is a schematic diagram of the guide plate structure of the present invention; Figure 7 This is a schematic diagram of the internal structure of the cylinder of the present invention; Figure 8 This is a schematic diagram of the cross-sectional structure of the ventilation duct of the present invention.

[0021] In the diagram: 1. Cabinet; 2. Workbench; 3. Glass sliding door; 4. Control panel; 5. Auxiliary ventilation mechanism; 51. Suction fan; 52. Filter component; 53. Air intake assembly; 531. Ventilation duct; 532. Auxiliary air cushion; 533. First magnetic block; 534. Second magnetic block; 535. Air inlet; 536. Piston block; 54. Pressure valve; 55. Support tube; 56. Limiting assembly; 561. Groove; 562. Cylinder; 563. Spring; 564. Moving plate; 565. Slide rod; 566. Screw; 567. Mounting plate; 57. 58. Air collection cylinder; 581. Air intake assembly; 582. Air intake hole; 583. Elastic rope; 584. Air permeable plate; 585. Sealing plate; 586. Honeycomb panel; 587. Nozzle; 59. Swing assembly; 591. Motor; 592. Circular plate; 593. Slide plate; 594. Circular rod; 595. Rack; 596. First gear; 597. Second gear; 598. Third gear; 599. Gear ring; 5910. Carbon rod; 5911. Fourth gear; 5912. Cleaning plate; 6. Main ventilation mechanism; 61. Main air intake; 62. Deflector plate. Detailed Implementation

[0022] 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 only 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.

[0023] Please see Figure 1-8 This invention provides a laboratory exhaust gas purification fume hood, including a cabinet 1. A workbench 2 is mounted on the top of the cabinet 1. An auxiliary ventilation mechanism 5 is provided on the top of the workbench 2. The auxiliary ventilation mechanism 5 includes a suction fan 51 fixedly mounted on the top of the workbench 2. Support pipes 55 are provided on both sides of the workbench 2. A filter component 52 for filtering exhaust gas is connected to the input end of the suction fan 51. A gas collecting cylinder 57 is rotatably mounted on the surface of the support pipes 55 near the inside of the workbench 2. The suction fan 51 is connected to an air inlet assembly 53. The air collecting cylinder 57 is connected to the interior. An air suction assembly 58 is provided on the outer surface of the air collecting cylinder 57. The air suction assembly 58 includes multiple nozzles 586 connected to and installed on the outer surface of the air collecting cylinder 57. Multiple air suction holes 581 are opened on the outer surface of the nozzles 586. A vent plate 583 is fixedly installed inside the nozzles 586. A sealing plate 584 is provided on the surface of the nozzles 586 away from the air suction holes 581 to block the vent plate 583. Multiple elastic ropes 582 are fixedly installed between the sealing plate 584 and the inner wall of the nozzles 586.

[0024] In the fume hood, a main ventilation mechanism 6 is installed at the top of the workbench 2. This mechanism exhausts the waste gas generated during experiments inside the workbench 2, filtering it through a filter component 52 before discharge. This achieves ventilation of the workbench 2, maintaining internal air pressure and environmental purification. Furthermore, two rotating air collection cylinders 57 of the auxiliary ventilation mechanism 5, in conjunction with nozzles 586, supplement the airflow at both ends of the glass sliding door 3, thus collecting waste gas from multiple directions around the workbench 2, improving waste gas purification efficiency and enhancing the working environment. Simultaneously, the nozzles 586 on the outer surface of the air collection cylinders 57 draw in waste gas through suction holes 581. A permeable plate 583 assists the airflow, and a sealing plate 584, under the action of an elastic rope 582, can seal or open the suction holes 581 according to air pressure and other conditions, preventing backflow of waste gas and secondary pollution inside the workbench 2.

[0025] In some embodiments, the nozzle 586 is provided with a honeycomb plate 585 for preliminary filtration inside, and a sedimentation tank is provided at the bottom end of the nozzle 586 near the honeycomb plate 585.

[0026] A honeycomb plate 585 is installed inside the nozzle 586. When exhaust gas passes through the nozzle 586, the honeycomb plate 585 performs preliminary filtration of the exhaust gas. Impurities in the exhaust gas are intercepted and settled in the sedimentation tank near the bottom of the honeycomb plate 585. This preliminary filtration of impurities in the exhaust gas reduces the burden on the subsequent filter components 52 and extends the service life of the filter components 52. At the same time, the sedimentation tank facilitates the cleaning of impurities and ensures the normal operation of the fume hood.

[0027] In some embodiments, the outer surface of the workbench 2 is provided with a swing assembly 59. The swing assembly 59 includes a motor 591 fixedly installed on the outer surface of the workbench 2. A circular plate 592 is fixedly installed on the output shaft of the motor 591. A circular rod 594 is fixedly installed on the top end of the circular plate 592. A third gear 598 is rotatably installed on the top end of the air collecting cylinder 57. A first gear 596 and a second gear 597 are rotatably installed on the top end of the support tube 55. The first gear 596 and the third gear 598 mesh through the second gear 597. A rack 595 is slidably installed on the top end of the support tube 55. The rack 595 meshes with the first gear 596. A slide plate 593 is fixedly installed on one end of the rack 595. The circular rod 594 is slidably installed inside the slide plate 593.

[0028] Specifically, the motor 591 drives the circular plate 592 to rotate, the circular plate 592 drives the circular rod 594 to rotate, the circular rod 594 drives the sliding plate 593 to reciprocate laterally, the sliding plate 593 drives the rack 595 to reciprocate laterally, the rack 595 drives the first gear 596 to reciprocate laterally, the first gear 596 drives the third gear 598 to rotate through the second gear 597, the third gear 598 drives the air collecting cylinder 57 to rotate, and the air collecting cylinder 57 drives the nozzle 586 to rotate, thereby realizing the multi-angle rotation of the nozzle 586. This further enables the nozzle 586 to cover the two ends of the glass sliding door 3 and the corners inside the cabinet, as well as other blind areas where exhaust gas can linger. This significantly improves the comprehensiveness and efficiency of exhaust gas collection, enhances the adsorption capacity of exhaust gas in different locations, and strengthens the exhaust gas purification effect.

[0029] In some embodiments, a carbon rod 5910 for initial odor adsorption is rotatably mounted inside the gas collecting cylinder 57, and the outer surface of the carbon rod 5910 has multiple channels. A toothed ring 599 is fixedly mounted on the top end of the carbon rod 5910, and a fourth gear 5911 is rotatably mounted on the top end of the carbon rod 5910. The toothed ring 599 and the third gear 598 mesh through the fourth gear 5911.

[0030] When the third gear 598 rotates, it drives the gear ring 599 to rotate through the fourth gear 5911. The gear ring 599 is fixed to the top of the carbon rod 5910, so that the carbon rod 5910 rotates inside the gas collecting cylinder 57. The channel opened on the outer surface of the carbon rod 5910 increases the contact area with the exhaust gas, allowing for more thorough contact with the exhaust gas, effectively adsorbing odors in the exhaust gas, further purifying the exhaust gas, and improving the air quality of the working environment.

[0031] In some embodiments, an arc-shaped cleaning plate 5912 is fixedly installed on the inner wall of the workbench 2 near the nozzle 586, and a cleaning sponge for cleaning the surface of the nozzle 586 is fixedly installed on the surface of the cleaning plate 5912 near the nozzle 586.

[0032] When the nozzle 586 rotates, the cleaning sponge on the arc-shaped cleaning plate 5912 on the inner wall of the workbench 2 comes into contact with the surface of the nozzle 586, cleans the surface of the nozzle 586, removes adsorbed dust and other impurities, keeps the surface of the nozzle 586 clean, prevents dust and other impurities from clogging the air intake hole 581, ensures that the nozzle 586 can draw air normally, and maintains a good exhaust gas adsorption effect.

[0033] In some embodiments, a limiting component 56 is provided on the outer surface of the workbench 2. The limiting component 56 includes a mounting plate 567 fixedly installed on the outer surface of the support tube 55. A groove 561 is provided inside the workbench 2. A cylinder 562 is fixedly installed inside the groove 561. A movable plate 564 is slidably installed inside the cylinder 562. A spring 563 is fixedly installed between the movable plate 564 and the inner wall of the cylinder 562. A slide rod 565 is fixedly installed on the outer surface of the movable plate 564. The mounting plate 567 is threadedly connected to the slide rod 565 by a screw 566.

[0034] The screw 566 allows for the installation of the air collecting cylinder 57 and the nozzle 586. After installation, the position of the mounting plate 567 can be adjusted by the spring 563 inside the cylinder 562, thereby limiting the support pipe 55 and ensuring the stability of components such as the air collecting cylinder 57. It also facilitates the disassembly and replacement of the air collecting cylinder 57 and the nozzle 586. At the same time, it can buffer and pressurize the position of the nozzle 586 to prevent the negative pressure environment inside the workbench 2 from squeezing and damaging the nozzle 586, so that the nozzle 586 can operate stably and ensure the exhaust gas purification effect.

[0035] In some embodiments, the air intake assembly 53 includes a ventilation duct 531 that connects the air collecting cylinder 57 and the suction fan 51. A plurality of first magnetic blocks 533 are fixedly installed inside the ventilation duct 531. An auxiliary air cushion 532 for protecting the duct is attached to the inner wall of the ventilation duct 531. A plurality of second magnetic blocks 534 are fixedly installed on the outer surface of the auxiliary air cushion 532. The first magnetic blocks 533 and the second magnetic blocks 534 are magnetically connected. One end of the auxiliary air cushion 532 is connected to an air inlet 535. The air inlet 535 is closed and fixed by a piston block 536.

[0036] When the ventilation duct 531 is in use, the auxiliary air cushion 532 is inflated through the air inlet 535 and the air inlet 535 is sealed by the piston block 536. The air inlet 535 can be opened as needed to supplement air. At the same time, with the adsorption effect of the first magnetic block 533 and the second magnetic block 534, the auxiliary air cushion 532 can be stably attached to the inside of the ventilation duct 531, thereby protecting the inner wall of the ventilation duct 531 and reducing the corrosion and other damage to the duct caused by exhaust gas. The auxiliary air cushion 532 can be quickly replaced, ensuring the long-term stable operation of the ventilation duct 531.

[0037] In some embodiments, the outer surface of the ventilation duct 531 is provided with a plurality of air pressure valves 54, and the air pressure valves 54 control the opening and closing of the ventilation duct 531 by the air pressure inside the workbench 2.

[0038] When the internal air pressure of the workbench 2 is abnormal, the air pressure valve 54 can control the opening and closing of the ventilation duct 531 according to the internal air pressure of the workbench 2, thereby adjusting the air intake of the ventilation duct 531 to balance the air pressure, ensuring that the fume hood can operate stably under different working conditions, and avoiding the impact of air pressure problems on the exhaust gas purification effect.

[0039] In some embodiments, the inner wall of the workbench 2 is provided with a main ventilation mechanism 6. The main ventilation mechanism 6 includes a plurality of main air intakes 61 opened on the workbench 2 near the filter component 52. The input end of the fan 51 is connected to the main air intakes 61 through the filter component 52. A guide plate 62 for air intake guidance is fixedly installed on the inner wall of the workbench 2 near the main air intakes 61.

[0040] The suction fan 51 is connected to the main suction port 61 through the filter component 52, realizing the main exhaust function of the waste gas generated in the experiment inside the workbench 2. The guide plate 62 guides the airflow entering the main suction port 61, so that the waste gas can smoothly enter the suction fan 51 and be discharged after being filtered by the filter component 52, ensuring stable air pressure and environmental purification inside the workbench 2.

[0041] In some embodiments, the outer surface of the workbench 2 is provided with a glass sliding door 3 for closing the workbench 2, and the top of the workbench 2 is provided with a control board 4. The control board 4 is electrically connected to the glass sliding door 3 and the suction fan 51 through a built-in power supply.

[0042] The glass sliding door 3 is used to enclose the workbench 2 to prevent exhaust gas leakage, and the control panel 4 can control the opening and closing of the exhaust fan 51 in the fume hood. It can conveniently control the opening and closing of the glass sliding door 3 and the operation of the exhaust fan 51 to prevent exhaust gas from spreading to the surrounding environment and ensure stable ventilation.

[0043] Working Principle: When the fume hood is in use, the main ventilation mechanism 6 exhausts the waste gas generated inside the workbench 2, and filters it through the filter component 52 before discharge, thereby achieving ventilation inside the workbench 2 and maintaining the internal air pressure and environmental purification. Furthermore, the two rotating air collecting cylinders 57 of the auxiliary ventilation mechanism 5, in conjunction with the nozzles 586, can supplement and absorb waste gas from both ends of the glass sliding door 3, thus collecting waste gas from multiple directions around the workbench 2, improving waste gas purification efficiency and improving the working environment. Simultaneously, the nozzles 586 on the outer surface of the air collecting cylinders 57 draw in waste gas through the suction holes 581, the permeable plate 583 assists the airflow, and the sealing plate 584, under the action of the elastic rope 582, can seal or open the suction holes 581 according to air pressure and other conditions, thereby preventing waste gas backflow and secondary pollution inside the workbench 2.

[0044] The above are merely specific embodiments of the present invention, but the technical features of the present invention are not limited thereto. Any simple changes, equivalent substitutions, or modifications made based on the present invention to solve essentially the same technical problems and achieve essentially the same technical effects are all covered within the protection scope of the present invention.

Claims

1. A laboratory exhaust gas purification fume hood, comprising a cabinet (1), characterized in that: A workbench (2) is installed on the top of the cabinet (1). An auxiliary ventilation mechanism (5) is provided on the top of the workbench (2). The auxiliary ventilation mechanism (5) includes a suction fan (51) fixedly installed on the top of the workbench (2). Support pipes (55) are provided on both sides of the workbench (2). A filter component (52) for filtering exhaust gas is connected to the input end of the suction fan (51). An air collection cylinder (57) is rotatably installed on the surface of the support pipe (55) near the inside of the workbench (2). The suction fan (51) is connected to the inside of the air collection cylinder (57) through an air inlet component (53). The outer surface of the air collecting cylinder (57) is provided with an air intake assembly (58). The air intake assembly (58) includes multiple nozzles (586) connected to and installed on the outer surface of the air collecting cylinder (57). Multiple air intake holes (581) are opened on the outer surface of the nozzles (586). A breathable plate (583) is fixedly installed inside the nozzles (586). A sealing plate (584) is provided on the surface of the nozzles (586) away from the air intake holes (581) to block the breathable plate (583). Multiple elastic ropes (582) are fixedly installed between the sealing plate (584) and the inner wall of the nozzles (586).

2. The laboratory exhaust gas purification fume hood according to claim 1, characterized in that: The nozzle (586) is provided with a honeycomb plate (585) for preliminary filtration inside, and a sedimentation tank is provided at the bottom of the nozzle (586) near the honeycomb plate (585).

3. The laboratory exhaust gas purification fume hood according to claim 1, characterized in that: The outer surface of the workbench (2) is provided with a swing assembly (59). The swing assembly (59) includes a motor (591) fixedly installed on the outer surface of the workbench (2). A circular plate (592) is fixedly installed on the output shaft of the motor (591). A circular rod (594) is fixedly installed on the top of the circular plate (592). A third gear (598) is rotatably installed on the top of the air collecting cylinder (57). A first gear (596) and a second gear (597) are rotatably installed on the top of the support tube (55). The first gear (596) and the third gear (598) mesh through the second gear (597). A rack (595) is slidably installed on the top of the support tube (55). The rack (595) meshes with the first gear (596). A slide plate (593) is fixedly installed on one end of the rack (595). The circular rod (594) is slidably installed inside the slide plate (593).

4. The laboratory exhaust gas purification fume hood according to claim 3, characterized in that: The gas collecting cylinder (57) is rotatably mounted with a carbon rod (5910) for initial adsorption of odors. The outer surface of the carbon rod (5910) has multiple channels. A toothed ring (599) is fixedly mounted on the top of the carbon rod (5910). A fourth gear (5911) is rotatably mounted on the top of the carbon rod (5910). The toothed ring (599) and the third gear (598) mesh through the fourth gear (5911).

5. A laboratory exhaust gas purification fume hood according to claim 1, characterized in that: An arc-shaped cleaning plate (5912) is fixedly installed on the inner wall of the workbench (2) near the nozzle (586), and a cleaning sponge for cleaning the surface of the nozzle (586) is fixedly installed on the surface of the cleaning plate (5912) near the nozzle (586).

6. The laboratory exhaust gas purification fume hood according to claim 1, characterized in that: The outer surface of the workbench (2) is provided with a limiting component (56). The limiting component (56) includes a mounting plate (567) fixedly installed on the outer surface of the support tube (55). The workbench (2) has a groove (561) inside. A cylinder (562) is fixedly installed inside the groove (561). A movable plate (564) is slidably installed inside the cylinder (562). A spring (563) is fixedly installed between the movable plate (564) and the inner wall of the cylinder (562). A slide rod (565) is fixedly installed on the outer surface of the movable plate (564). The mounting plate (567) is threadedly connected to the slide rod (565) by a screw (566).

7. A laboratory exhaust gas purification fume hood according to claim 1, characterized in that: The air intake assembly (53) includes a ventilation duct (531) that connects the air collecting cylinder (57) and the suction fan (51). A plurality of first magnetic blocks (533) are fixedly installed inside the ventilation duct (531). An auxiliary air cushion (532) for protecting the duct is attached to the inner wall of the ventilation duct (531). A plurality of second magnetic blocks (534) are fixedly installed on the outer surface of the auxiliary air cushion (532). The first magnetic blocks (533) and the second magnetic blocks (534) are magnetically connected. An air inlet (535) is connected to one end of the auxiliary air cushion (532). The air inlet (535) is closed and fixed by a piston block (536).

8. A laboratory exhaust gas purification fume hood according to claim 7, characterized in that: The outer surface of the ventilation duct (531) is provided with multiple air pressure valves (54), and the air pressure valves (54) control the opening and closing of the ventilation duct (531) through the air pressure inside the workbench (2).

9. A laboratory exhaust gas purification fume hood according to claim 1, characterized in that: The inner wall of the workbench (2) is provided with a main ventilation mechanism (6). The main ventilation mechanism (6) includes multiple main air intakes (61) opened on the workbench (2) near the filter component (52). The input end of the suction fan (51) is connected to the main air intakes (61) through the filter component (52). A guide plate (62) for air suction guidance is fixedly installed on the inner wall of the workbench (2) near the main air intakes (61).

10. A laboratory exhaust gas purification fume hood according to claim 1, characterized in that: The outer surface of the workbench (2) is provided with a glass sliding door (3) for closing the workbench (2), and a control board (4) is provided at the top of the workbench (2). The control board (4) is electrically connected to the glass sliding door (3) and the suction fan (51) through a built-in power supply.

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