Waste gas treatment equipment for laboratory fume hood

Abstract

The invention relates to the technical field of waste gas treatment, and discloses waste gas treatment equipment for a laboratory fume hood, the waste gas treatment equipment comprises a cabinet body, the cabinet body is an overall equipment supporting carrier, a top box is fixedly mounted at the top of the cabinet body, and a movable cabinet door is slidably assembled on the front side of the cabinet body in the vertical direction; a plurality of air adjusting plates distributed at equal intervals are rotatably mounted at the inner bottom of the top box through rotating shafts, a sliding groove is formed in one side of the bottom of the top box, a rack plate is slidably mounted in the sliding groove, and a plurality of driving gears are connected to the outer side of the rack plate in an engaged mode. Opening and closing of the air adjusting plate and adjustment of the spraying liquid pushing amount are synchronously linked through the sliding action of the movable cabinet door, so that the waste gas collecting flow and the spraying neutralization amount are accurately matched with the actual experiment operation state of a laboratory, manual real-time intervention is not needed, waste gas overflow and invalid waste of the spraying liquid are effectively avoided, and the working efficiency is improved. The automation degree of waste gas treatment is greatly improved, and diversified experiment operation waste gas treatment requirements of a laboratory are met.

Description

Technical Field

[0001] The present invention relates to the technical field of waste gas treatment, and particularly to a waste gas treatment device for a laboratory fume hood. Background Art

[0002] As the core place for scientific research and experimental operations, laboratories are extremely likely to generate various toxic, harmful, and irritating waste gases during operations such as chemical synthesis, sample processing, and reagent reactions. If directly discharged into the laboratory environment or the atmosphere, it will not only cause serious harm to the physical health of experimental operators, leading to injuries in parts such as the respiratory tract and skin mucosa, but also pollute the surrounding ecological environment of the laboratory. At the same time, some flammable and explosive waste gases also pose safety hazards. Therefore, as the core equipment for collecting laboratory waste gases, the supporting waste gas treatment device has become a key component for the safe and environmentally friendly operation of laboratories, which needs to achieve timely collection and effective purification of the waste gases in the fume hood to ensure that the waste gases are discharged up to standard.

[0003] At present, various technical solutions have been formed for the waste gas treatment equipment supporting existing laboratory fume hoods. The mainstream equipment usually includes core structures such as waste gas diversion, spray neutralization, filtration purification, and terminal discharge, and can basically achieve the basic treatment of laboratory waste gases. In the waste gas diversion link, existing equipment mostly adjusts the waste gas flow rate through the opening and closing of the fume hood door in cooperation with the frequency conversion of the fan, that is, when the door is opened, the fan increases the rotation speed to increase the air extraction volume, and when the door is closed, the rotation speed is reduced to reduce the air extraction volume; in the spray neutralization link, the method of quantitative spraying or manual adjustment of the spraying amount is mostly adopted, and acid-base neutralization and dust reduction treatment are achieved through the contact between the spraying liquid and the waste gas; in the filtration purification link, structures such as filter screens and activated carbon adsorption layers are generally set up to intercept solid impurities in the waste gas and adsorb harmful gases; at the same time, in order to prevent the filter screen from being blocked, some equipment also adds a simple back-blowing structure to clean the impurities on the surface of the filter screen through air flow blowing.

[0004] These existing technologies have solved the problem of laboratory waste gas treatment to a certain extent and achieved the collection and purification of waste gases. However, in the actual application process in laboratories, many technical defects are still exposed, and it is difficult to adapt to the diverse and dynamic experimental operation requirements of laboratories. The specific technical problems are as follows: Firstly, the adjustment of exhaust gas flow rate and spray volume lacks precise linkage and adaptability, resulting in low exhaust gas treatment efficiency and resource utilization. Existing equipment relies heavily on individual control of fan frequency conversion and cabinet door opening / closing for exhaust gas flow rate adjustment, while spray volume adjustment is either independent quantitative control or manual adjustment. This fails to achieve synchronous and linear adjustment of exhaust gas flow rate and spray volume based on the actual opening range of the fume hood door. When the cabinet door is slightly open and the exhaust gas flow rate is low during experiments, the equipment maintains quantitative spraying, easily leading to significant waste of spray liquid. Conversely, when the cabinet door is significantly open and the exhaust gas flow rate increases sharply, the spray volume does not increase in time, resulting in insufficient contact between the exhaust gas and spray liquid, significantly reducing acid-base neutralization and dust reduction effects. Some untreated exhaust gas directly enters subsequent stages, reducing overall exhaust gas treatment efficiency and even posing a risk of failing to meet emission standards. Furthermore, some electronically controlled adjustment equipment is complex in structure, has a high failure rate, and poor adaptability to the humid and corrosive environments of laboratories, making it prone to short circuits and component damage.

[0005] Secondly, the coordination between filter clogging prevention and clogging detection is poor, making it difficult to guarantee the continuity and stability of equipment operation. Existing equipment's filter backflushing structures are mostly fixed-frequency, timed purging, unable to achieve adaptive backflushing based on the actual clogging state of the filter. The timing and intensity of purging lack precise control. Therefore, those skilled in the art propose a waste gas treatment device for laboratory fume hoods to solve these problems. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a waste gas treatment device for laboratory fume hoods, which solves the problems mentioned in the background section.

[0007] To achieve the above objectives, the present invention is implemented through the following technical solution: a waste gas treatment device for a laboratory fume hood, comprising: a cabinet body, wherein the cabinet body is the overall support carrier of the device, a top box is fixedly installed on the top of the cabinet body, and a movable cabinet door is slidably assembled on the front side along the vertical direction; The inner bottom of the top box is rotatably mounted with multiple equally spaced air regulating plates via a rotating shaft. A sliding groove is provided on one side of the bottom of the top box, within which a rack plate is slidably mounted. Multiple drive gears are meshed with the outer side of the rack plate, and each drive gear is fixedly connected to the rotating shaft of a corresponding air regulating plate. A rigid traction rope is fixedly connected to one side of the rack plate, with the end of the rigid traction rope away from the rack plate fixedly connected to the inner side of the movable cabinet door. The sliding of the movable cabinet door moves the rack plate, causing the multiple drive gears to rotate and thus regulating the airflow. The plates open and close synchronously to regulate the flow of exhaust gas. A fixed plate is fixedly connected to the side of the rack plate away from the rigid traction rope. The outer surface of the fixed plate has an inclined groove. A drive shaft is slidably installed on the rear side of the cabinet in the horizontal direction. An installation cylinder is also fixedly connected to the rear side of the cabinet. A movable plate is slidably connected inside the installation cylinder. A connecting pipe one and a connecting pipe three are connected in sequence along the axial direction on the outer surface. The end of the connecting pipe one away from the installation cylinder is connected to a spray pipe through a transport pump. A flow meter for detecting the flow of spray liquid is also installed inside the installation cylinder.

[0008] Preferably, a movable block is fixedly provided at one end of the drive shaft near the fixed plate. The movable block is slidably adapted to the inner wall of the inclined groove. The end of the drive shaft away from the fixed plate is fixedly connected to the outer center position of the movable plate. The movement of the rack plate drives the fixed plate to move synchronously. The sliding cooperation between the inclined groove and the movable block drives the drive shaft to move horizontally, thereby linking the movable plate to slide axially in the installation cylinder, thereby realizing the adjustment of the spray liquid pushing volume in the installation cylinder.

[0009] Preferably, a pump body is fixedly connected to the rear side of the cabinet. The output end of the pump body is fixedly connected to the end of the connecting pipe three away from the installation cylinder. The input end of the pump body is fixedly connected to the connecting pipe two. A storage tank for storing spray liquid is also fixedly connected to the rear side of the cabinet. The end of the connecting pipe two away from the pump body is connected to the inside of the storage tank. The automatic extraction of spray liquid in the storage tank and its delivery to the installation cylinder are realized by starting and stopping the pump body.

[0010] Preferably, control valves are fixedly installed on the outside of both the first and third connecting pipes. The two control valves are independent on / off control structures, which can control the on / off state and opening degree of the connecting pipes one and three respectively. One end of the first connecting pipe is connected to a spray pipe through a transport pump.

[0011] Preferably, an installation box is fixedly connected to the outside of the cabinet. Two electric telescopic rods are symmetrically installed on one side of the bottom of the installation box, and two fixed cylinders are symmetrically fixedly connected to the other side of the bottom of the installation box. The fixed cylinders have installation grooves inside, and rubber pistons are slidably connected to the inside of the fixed cylinders along the axial direction. A movable rod is fixedly connected to the side of the rubber piston away from the installation box. The end of the movable rod away from the rubber piston is fixedly connected to the output end of the electric telescopic rod. The extension and retraction of the electric telescopic rod drives the movable rod to move back and forth, which in turn causes the rubber piston to slide axially inside the fixed cylinder, creating a pressure difference inside the fixed cylinder.

[0012] Preferably, the outer surface of the fixed cylinder is sequentially connected to an air inlet pipe and a connecting pipe along the axial direction. The end of the connecting pipe away from the fixed cylinder is connected to the interior of the mounting box, and multiple high-pressure nozzles are evenly arranged at the end of the connecting pipe that extends into the mounting box. One-way valves are fixedly installed inside both the air inlet pipe and the connecting pipe, and the internal conduction directions of the two one-way valves are opposite. The one-way valve in the air inlet pipe conducts to the fixed cylinder, and the one-way valve in the connecting pipe conducts to the mounting box, thereby realizing one-way gas extraction and high-pressure injection.

[0013] Preferably, two sets of mounting plates are symmetrically fixedly connected inside the mounting box. The bottom of each set of mounting plates is rotatably mounted with a movable shaft via a bearing. A filter screen is slidably sleeved on the outside of the movable shaft. The filter screen is adapted to the internal channel of the mounting box. A sensing plate is fixedly connected to the side of the mounting plate facing the filter screen. A trigger plate adapted to the sensing plate is provided on the outside of the filter screen. A return spring is also fixedly connected to the outside of the movable shaft. The end of the return spring away from the filter screen is fixedly connected to the inside of the mounting plate. The air pressure difference generated by the blockage on both sides of the filter screen pushes the trigger plate to move towards the sensing plate, thereby realizing the automatic detection of filter screen blockage.

[0014] Preferably, the trigger plate is an elastic metal plate, and the trigger plate is located on the exhaust gas inflow side of the filter screen, and the elastic force of the reset spring matches the preset air pressure threshold of the filter screen blockage.

[0015] Preferably, an exhaust channel is fixedly connected to the side of the mounting box away from the cabinet. One end of the exhaust channel is connected to the interior of the mounting box, and the other end is used to connect to a fan and an exhaust pipe.

[0016] Preferably, the sliding groove of the inner wall of the top box that mates with the rack plate is a dovetail groove structure, and the end of the rack plate is a dovetail block structure that matches the dovetail groove. A second mounting box is also fixedly connected to the outside of the cabinet. The second mounting box is placed on the outside of the pump body and the storage box to provide protection for them.

[0017] This invention provides a waste gas treatment device for laboratory fume hoods. It has the following beneficial effects: 1. This invention realizes mechanical linkage adaptive control of the entire process of waste gas treatment. By synchronously linking the opening and closing of the air regulating plate and the adjustment of the spray liquid push volume through the sliding action of the movable cabinet door, the waste gas collection flow rate and spray neutralization volume are precisely matched with the actual experimental operation state in the laboratory. No real-time manual intervention is required. This effectively avoids waste gas overflow and ineffective waste of spray liquid, and greatly improves the automation level of waste gas treatment, adapting to the diverse experimental operation waste gas treatment needs of the laboratory.

[0018] 2. This invention addresses the filter clogging problem by employing a dual-protection structure combining high-pressure jet backwash anti-clogging and purely mechanical physical triggering clogging detection. High-pressure airflow continuously backwashes the filter through the nozzle at the end of the connecting pipe, shaking off attached impurities at the source and reducing the probability of clogging. When the filter becomes severely clogged, the pressure difference on both sides of the filter pushes the trigger plate and the sensing plate to form a rigid contact detection signal, which can be quickly converted into an audible and visual alert. This enables real-time detection and timely maintenance of filter clogging, ensuring filter filtration efficiency and the continuity of overall equipment operation, and effectively reducing manual inspection and maintenance costs.

[0019] 3. This equipment adopts a modular structural design and targeted protection measures. The functional modules are closely connected and the operating logic is closed-loop. The overall structure is adapted to the complex operating environment of laboratory acid and alkaline waste gas and humidity. This not only improves the stability and accuracy of equipment operation, but also extends the service life of core components and reduces the long-term use and maintenance costs of the equipment. Attached Figure Description

[0020] Figure 1 This is a perspective view of the present invention; Figure 2 This is a schematic diagram of the air regulating plate structure of the present invention; Figure 3 This is a schematic diagram of the cabinet structure of the present invention; Figure 4 This is a schematic diagram of the storage box structure of the present invention; Figure 5 This is a schematic diagram of the connecting pipe structure of the present invention; Figure 6 for Figure 2 Enlarged view of point A in the middle; Figure 7 for Figure 3 Enlarged view of point B in the middle; Figure 8 This is a schematic diagram of the storage box structure of the present invention; Figure 9 for Figure 8 Enlarged view of point C in the middle; Figure 10 This is a schematic diagram of the installation box structure of the present invention; Figure 11This is a schematic diagram of the connecting pipe structure of the present invention; Figure 12 This is a cross-sectional view of the regulating cylinder of the present invention.

[0021] The components are as follows: 1. Cabinet body; 2. Mounting box one; 3. Movable cabinet door; 4. Top box; 5. Connecting pipe; 6. Fixing cylinder; 7. Air regulating plate; 8. Mounting box two; 9. Fixing plate; 10. Exhaust channel; 11. Mounting cylinder; 12. Storage box; 13. Connecting pipe one; 14. Electric telescopic rod; 15. Rack plate; 16. Drive gear; 17. Drive shaft; 18. Inclined groove; 19. Pump body; 20. Connecting pipe two; 21. Filter screen; 22. Mounting plate; 23. Movable shaft; 24. Return spring; 25. Sensor plate; 26. Connecting pipe three; 27. Movable rod; 28. Movable plate; 29. ​​Rubber piston; 30. Air inlet pipe; 31. One-way valve; 32. Mounting groove; 33. Rigid traction rope. Detailed Implementation

[0022] The technical solutions in 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 the appendix Figure 1 - Appendix Figure 12 This invention provides a waste gas treatment device for a laboratory fume hood, including a cabinet 1. The cabinet 1 serves as the overall support carrier for the device and is integrally formed from stainless steel. Its shape is adapted to the exhaust end of the laboratory fume hood and can be directly fixedly connected to the fume hood. A top box 4 is fixedly installed on the top of the cabinet 1 by bolts. The top box 4 is a hollow cuboid structure and serves as the core cavity for guiding waste gas. A sliding groove is provided on the front side of the cabinet 1 along the vertical direction. A movable cabinet door 3 is slidably fitted in the sliding groove. The movable cabinet door 3 is made of transparent tempered glass, which does not affect the experimental operation vision and can realize the opening and closing control of the fume hood operation end. Its sliding stroke matches the opening range of the cabinet door in conventional laboratory experimental operations, with a maximum sliding stroke of 80cm.

[0024] The bottom of the top box 4 is rotatably mounted with multiple equal-spaced air regulating plates 7. In this embodiment, there are 10 air regulating plates 7, each of which is an arc-shaped stainless steel plate. The arc-shaped structure is adapted to the internal cavity of the top box 4, which can effectively reduce the resistance to the flow of exhaust gas. A sliding groove is provided on one side of the bottom of the top box 4. The sliding groove is a dovetail groove structure. A rack plate 15 is slidably installed in the sliding groove. The end of the rack plate 15 is a dovetail block structure adapted to the dovetail groove, which can effectively prevent the rack plate 15 from shifting or jamming during the sliding process and ensure the stability of the transmission. Multiple drive gears 16 are meshed on the outer side of the rack plate 15. The number of drive gears 16 corresponds one-to-one with the air regulating plate 7, and each drive gear 16 is fixedly connected to the rotating shaft of the corresponding air regulating plate 7 through a flat key, so as to realize the synchronous rotation of the gear and the rotating shaft. A rigid traction rope 33 is fixedly connected to one side of the rack plate 15 by a buckle. In this embodiment, the rigid traction rope 33 is a stainless steel wire rope with high strength and corrosion resistance. The end away from the rack plate 15 is welded and fixed to the inner side of the movable cabinet door 3. The rack plate 15 moves linearly along the dovetail groove by sliding the movable cabinet door 3, thereby linking multiple drive gears 16 to rotate synchronously and driving the air regulating plate 7 to open and close synchronously around the rotating shaft, so as to realize the flow regulation of the exhaust gas passage. The opening range of the movable cabinet door 3 is linearly related to the unfolding angle of the air regulating plate 7. The larger the opening range, the larger the unfolding angle of the air regulating plate 7, and the greater the exhaust gas flow rate.

[0025] A fixing plate 9 is welded and fixed to the side of the rack plate 15 away from the rigid traction rope 33. The fixing plate 9 is a stainless steel straight plate with a slanted groove 18 on its outer surface. The slanted groove 18 has an inclination angle of 45°, which is adapted to the horizontal movement stroke of the drive shaft 17. The drive shaft 17 is slidably installed on the rear side of the cabinet 1 along the horizontal direction through a guide sleeve. The drive shaft 17 is a stainless steel round shaft. A movable block is welded and fixed to one end of the drive shaft 17 near the fixing plate 9. The movable block has a cylindrical structure and is slidably adapted to the inner wall of the slanted groove 18. It can slide within the slanted groove 18 and convert the horizontal movement of the fixing plate 9 into the horizontal reciprocating linear movement of the drive shaft 17. The rear side of the cabinet 1 is also fixed with a bracket welded to the mounting cylinder 11. The mounting cylinder 11 is a stainless steel sealed cylinder with a movable plate 28 slidably connected inside. The outer side of the movable plate 28 is fitted with a fluororubber sealing ring to ensure the sealing performance with the inner wall of the mounting cylinder 11 and prevent the spray liquid from leaking. The end of the drive shaft 17 away from the fixed plate 9 is welded and fixed to the outer center position of the movable plate 28. The horizontal movement of the drive shaft 17 is linked to the movable plate 28 to slide axially in the mounting cylinder 11, changing the effective push chamber volume of the spray liquid in the mounting cylinder 11.

[0026] The outer surface of the mounting cylinder 11 is axially connected to a connecting pipe 13 and a connecting pipe 26. In this embodiment, both connecting pipes 13 and 26 are corrosion-resistant pipes, and their connection points with the mounting cylinder 11 are sealed by heat fusion. The end of connecting pipe 13 furthest from the mounting cylinder 11 is connected to a spray pipe via a transport pump. The spray pipe extends into the top box 4, and multiple atomizing nozzles are evenly installed on the spray pipe to atomize the spray liquid and increase the contact area with the exhaust gas. A flow meter is also installed inside the mounting cylinder 11. In this embodiment, the flow meter is a rotor flow meter, which can detect the flow rate of the spray liquid inside the mounting cylinder 11 in real time, providing data support for spray volume control. Control valves are fixedly installed on the outside of both connecting pipes 13 and 26 via flanges. The two control valves are independently on / off ball valves, which can control the on / off state and opening degree of connecting pipes 13 and 26 respectively, achieving precise control of the spray liquid delivery.

[0027] A pump body 19 is welded to the rear of cabinet 1 via a bracket. Its output end is connected to the end of connecting pipe 26 away from the mounting cylinder 11 via a flange, and its input end is connected to connecting pipe 20 via a flange. Connecting pipe 20 is also a corrosion-resistant pipe. A storage tank 12 is also welded to the rear of cabinet 1 via a bracket. Storage tank 12 is a polyethylene corrosion-resistant tank used to store spray liquids suitable for different types of laboratory waste gases, such as alkaline spray liquids for treating acidic waste gases and acidic spray liquids for treating alkaline waste gases. The end of connecting pipe 20 away from pump body 19 extends to the bottom of the storage tank 12. The automatic extraction and delivery of spray liquid from storage tank 12 to mounting cylinder 11 is achieved by starting and stopping pump body 19. A mounting box 8 is bolted to the outside of cabinet 1. Mounting box 8 is a stainless steel box that covers pump body 19 and storage tank 12, providing corrosion and dust protection for the core power and storage components, and isolating them from corrosion by laboratory acid and alkaline waste gases and moisture.

[0028] The outer side of cabinet 1 is bolted to mounting box 2, which is a hollow stainless steel box and serves as the core cavity for exhaust gas filtration and high-pressure backflushing. It is connected to the exhaust gas outlet of top box 4 to achieve continuous exhaust gas delivery. Two electric telescopic rods 14 are symmetrically installed on one side of the bottom of mounting box 2. In this embodiment, the electric telescopic rods 14 are electric hydraulic telescopic rods with a rated stroke of 10-20cm, capable of reciprocating telescopic movement. Two fixing cylinders 6 are symmetrically welded to the other side of the bottom of mounting box 2. The fixing cylinders 6 are stainless steel cylinders with mounting grooves 3 inside. 2. A rubber piston 29 is slidably connected along the axial direction in the mounting groove 32. The rubber piston 29 is made of fluororubber and has the characteristics of high temperature resistance, corrosion resistance and good sealing performance. A movable rod 27 is welded and fixed on the side of the rubber piston 29 away from the mounting box 2. The movable rod 27 is a stainless steel round rod. Its end away from the rubber piston 29 is fixedly connected to the output end of the electric telescopic rod 14 through a flange. The extension and retraction of the electric telescopic rod 14 drives the movable rod 27 to move back and forth, thereby linking the rubber piston 29 to slide along the axial direction in the fixed cylinder 6, so that negative pressure and positive pressure are alternately formed inside the fixed cylinder 6.

[0029] An air inlet pipe 30 and a connecting pipe 5 are sequentially connected along the axial direction on the outer surface of the fixed cylinder 6. Both the air inlet pipe 30 and the connecting pipe 5 are stainless steel pipes and are sealed and welded to the fixed cylinder 6. The end of the connecting pipe 5 away from the fixed cylinder 6 is connected to the interior of the mounting box 2, and multiple high-pressure nozzles are uniformly welded and fixed to the end of the connecting pipe 5 that extends into the mounting box 2. In this embodiment, there are 4 high-pressure nozzles on each connecting pipe 5. The nozzles are set facing the filter screen 21 inside the mounting box 2 to realize the reverse injection of high-pressure airflow. One-way valves 31 are fixedly installed inside the air inlet pipe 30 and the connecting pipe 5 by clamps. The internal conduction directions of the two one-way valves 31 are opposite. The one-way valve 31 in the air inlet pipe 30 conducts to the interior of the fixed cylinder 6, and the one-way valve 31 in the connecting pipe 5 conducts to the interior of the mounting box 2, realizing one-way gas extraction and high-pressure injection and avoiding airflow backflow.

[0030] Inside the mounting box 2, two sets of mounting plates 22 are symmetrically welded and fixed. Each mounting plate 22 has a movable shaft 23 mounted on its bottom via bearings. The bearings are made of corrosion-resistant stainless steel, ensuring the flexible rotation of the movable shaft 23. A filter screen 21 is slidably sleeved onto the outside of the movable shaft 23. The filter screen 21 is a composite structure of stainless steel wire mesh and activated carbon filter cloth, with a mesh size of 200 mesh. It can effectively intercept fine dust and solid particles in the exhaust gas, while also adsorbing some organic waste gas. The filter screen 21 and the inner... The filter screen 21 is adapted to the channel to ensure that the exhaust gas passes through the filter screen 21 without any dead angles; the mounting plate 22 is fixedly connected to the side of the filter screen 21 by bolts with a sensing plate 25. In this embodiment, the sensing plate 25 is a metal contact sensing plate 25, which is electrically connected to the control terminal of the laboratory exhaust gas treatment equipment; a trigger plate adapted to the sensing plate 25 is welded and fixed to the outside of the filter screen 21. The trigger plate is an elastic metal plate and is set on the exhaust gas inflow side of the filter screen 21, which can accurately sense the air pressure changes on both sides of the filter screen 21.

[0031] A return spring 24 is also sleeved on the outside of the movable shaft 23. The return spring 24 is a stainless steel corrosion-resistant spring. One end of it is welded and fixed to the outside of the filter screen 21, and the other end is welded and fixed to the inside of the mounting plate 22. The elastic force of the return spring 24 matches the preset air pressure threshold for filter screen 21 blockage. In this embodiment, the preset air pressure threshold is 5 kPa. When the air pressure difference on both sides of the filter screen 21 reaches this threshold, the air pressure difference can overcome the elastic force of the return spring 24 and push the filter screen 21 to move along the movable shaft 23 toward the sensing plate 25, so that the trigger plate contacts the sensing plate 25, thereby realizing the automatic detection of filter screen 21 blockage.

[0032] An exhaust channel 10 is welded and fixed on the side of the mounting box 1 away from the cabinet 1. The exhaust channel 10 is a stainless steel pipe with an inner diameter that matches the inner diameter of the internal channel of the mounting box 12, ensuring that the exhaust gas is discharged smoothly without stagnation or accumulation. One end of the exhaust channel 10 is connected to the interior of the mounting box 12, and the other end is used to connect the fan and the main exhaust gas discharge pipeline of the laboratory through a flange. Under the negative pressure traction of the fan, the exhaust gas is discharged at the terminal, completing the closed loop of the entire exhaust gas treatment process.

[0033] Working Principle: When laboratory operators open the movable cabinet door 3 for experimental operations, the sliding motion of the movable cabinet door 3 is transmitted to the rack plate 15 via the rigid traction rope 33, causing the rack plate 15 to move linearly along the sliding groove of the top box 4. The rack plate 15 meshes with the drive gear 16, which synchronously drives the rotating shaft of the air regulating plate 7 to rotate, causing multiple air regulating plates 7 to open and close synchronously around the rotating shaft. The opening range of the movable cabinet door 3 is linearly related to the unfolding angle of the air regulating plate 7: the larger the opening range of the cabinet door, the longer the moving distance of the rack plate 15, the larger the unfolding angle of the air regulating plate 7, and the larger the cross-sectional area of ​​the exhaust gas channel in the top box 4, thus increasing the exhaust gas flow rate. Conversely, when the cabinet door is closed, the air regulating plate 7 gradually closes, and the exhaust gas flow rate decreases accordingly. This process, through pure mechanical linkage, achieves precise matching between experimental operations and exhaust gas collection flow rate, ensuring that the exhaust gas generated in the fume hood can be timely and comprehensively guided to the subsequent treatment module, preventing exhaust gas from overflowing into the laboratory environment.

[0034] While the exhaust gas is being guided, the movement of the rack plate 15 synchronously drives the fixed plate 9 to make linear displacement in the same direction. The inclined groove 18 on the fixed plate 9 forms a sliding fit with the movable block at the end of the drive shaft 17, converting the horizontal movement of the fixed plate 9 into the horizontal reciprocating linear motion of the drive shaft 17, thereby pushing the movable plate 28 to make sealed sliding in the mounting cylinder 11, changing the cavity volume related to the spray liquid delivery in the mounting cylinder 11, thereby achieving precise control of the spray volume. After the equipment is started, the pump body 19 continuously draws spray liquid from the storage tank 12 and delivers it to the installation cylinder 11 through the connecting pipe 20 and the connecting pipe 3 26. The flow meter on the installation cylinder 11 monitors the spray liquid flow rate in real time. When the spray liquid in the cavity inside the installation cylinder 11 is full, the control valve of the connecting pipe 3 26 is closed and the control valve of the connecting pipe 1 13 is opened. With the on / off and opening degree adjustment of the independent control valves on the connecting pipe 1 13 and the connecting pipe 3 26, the amount of spray liquid pushed is precisely controlled according to the sliding position of the movable plate 28. The high-pressure spray liquid is delivered to the spray pipe through the transport pump and the connecting pipe 1 13 to fully spray, neutralize and reduce dust in the exhaust gas. When the exhaust gas flow rate is low and the concentration is low, the movable plate 28 moves to reduce the volume of the cavity inside the installation cylinder 11, and the amount of spray liquid pushed is reduced accordingly. This ensures the treatment effect while avoiding the ineffective waste of spray liquid.

[0035] When the electric telescopic rod 14 is energized, it reciprocates and extends. The power at its output end is transmitted to the rubber piston 29 through the movable rod 27, causing the rubber piston 29 to slide axially back and forth inside the fixed cylinder 6, thus creating alternating negative and positive pressure states inside the fixed cylinder 6. With the help of the one-way valve 31 that conducts in the opposite direction inside the air inlet pipe 30 and the connecting pipe 5, the fixed cylinder 6 draws in outside air through the air inlet pipe 30 during the negative pressure stage, and compresses the internal gas to form a high-pressure airflow during the positive pressure stage. The high-pressure airflow is transported to the inside of the mounting box 2 through the connecting pipe 5, and is precisely sprayed in the opposite direction towards the filter end face of the filter screen 21 through multiple high-pressure nozzles at the end of the connecting pipe 5. The high-pressure backflow directly impacts the surface of the filter screen 21, quickly shaking off dust, solid particles and other impurities that adhere to the filter screen 21 during the exhaust gas filtration process. This prevents impurities from accumulating in the pores of the filter screen 21 and causing blockage, thus ensuring the filtration diameter and exhaust gas flow efficiency of the filter screen 21. At the same time, a small amount of diffused high-pressure airflow can disturb the exhaust gas flow state inside the installation box 2, allowing the exhaust gas to come into contact with the spray droplets again, thereby enhancing the auxiliary effect of spray neutralization.

[0036] After being neutralized by spraying, the exhaust gas enters the installation box 2 under the negative pressure of the fan. It first flows through two symmetrically arranged filter screens 21. During the process of the exhaust gas passing through the filter screens 21, fine dust, solid particles, spray liquid condensation nuclei, and other impurities are effectively intercepted by the filter screens 21, achieving solid-liquid separation and impurity purification of the exhaust gas. The filter end face of the filter screen 21 is perfectly matched with the internal channel of the installation box 2, ensuring that the exhaust gas passes through the filter screen 21 without any dead angles, guaranteeing comprehensive filtration. Furthermore, throughout the filtration process, the high-pressure jet backwash structure operates continuously, promptly removing impurities adhering to the surface of the filter screen 21, keeping the filter screen 21 in good filtration condition at all times. The filtered exhaust gas has a significantly reduced impurity content, providing a guarantee for subsequent terminal emissions, while also preventing impurities from adhering to the inner wall of the exhaust channel 10, preventing the pipe diameter from decreasing and the exhaust resistance from increasing after long-term use.

[0037] The equipment is equipped with a purely mechanical physical trigger filter 21 clogging detection structure. When the filter 21 is still severely clogged even if the air jet backflushing cannot prevent it, it can sense the clogging status in real time and output a clear physical trigger signal to promptly provide feedback on maintenance needs and ensure the long-term unobstructed flow of the filtration channel.

[0038] Normal standby state: When the filter screen 21 is filtering normally with the assistance of jet backflushing, the resistance of the exhaust gas passing through the filter screen 21 is very small, the air pressure difference on both sides of the filter screen 21 is at a preset low value, the reset spring 24 is in a naturally extended state, the filter screen 21 maintains its initial position, and the trigger pressure plate on its outer side and the sensing plate 25 on the mounting plate 22 maintain a preset gap. At this time, the blockage detection structure has no signal output, and the equipment continues to operate normally.

[0039] Severe clogging triggering process: If too many impurities adhere to the filter screen 21, exceeding the cleaning capacity of the jet backflushing, the resistance of the exhaust gas passing through the filter screen 21 will increase sharply. The air pressure on the exhaust gas inflow side of the filter screen 21 will be significantly higher than that on the outflow side, forming an air pressure difference exceeding the preset threshold. This air pressure difference will overcome the elastic force of the return spring 24, pushing the filter screen 21 along the movable shaft 23 towards the sensing plate 25. When the degree of clogging of the filter screen 21 reaches the preset critical value, the trigger plate will make rigid physical contact with the sensing plate 25. This mechanical contact action is the core clogging detection trigger signal.

[0040] Signal feedback and reset: The mechanical contact signal can be directly transmitted to the control end of the equipment, and the control end converts it into an audible and visual reminder signal. The warning light at the laboratory end lights up and the buzzer sounds, clearly reminding the maintenance personnel that the filter 21 is severely clogged and needs to be replaced in time. After the maintenance personnel replace the filter 21, the air pressure difference on both sides of the filter 21 immediately returns to normal. The elastic force of the reset spring 24 pushes the filter 21 to move in the opposite direction along the movable shaft 23 to the initial position. The trigger plate separates from the sensing plate 25, the mechanical contact trigger signal disappears, the blockage detection structure completes the reset, and the equipment returns to normal filtration and detection status.

[0041] After undergoing multi-stage treatment, the exhaust gas is discharged in compliance with standards through the terminal emission module. Simultaneously, the equipment's multi-layered protective structure provides targeted protection for each core component, extending the overall service life of the equipment and adapting to the complex acid, alkali, and humid operating environment of the laboratory. The purified exhaust gas, under the continuous negative pressure of the fan, enters the laboratory's main exhaust duct through the exhaust channel 10 on mounting box 2, completing the closed loop of the entire exhaust gas treatment process. The diameter of the exhaust channel 10 is matched to the internal channel of mounting box 2, ensuring smooth exhaust gas discharge without stagnation or accumulation, and preventing exhaust gas from flowing back into the fume hood or laboratory due to poor ventilation.

[0042] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A waste gas treatment device for laboratory fume hoods, characterized in that, include: Cabinet (1), the cabinet (1) is the overall support carrier of the equipment, the top box (4) is fixedly installed on the top of the cabinet (1), and the movable cabinet door (3) is slidably assembled on the front side along the vertical direction. The bottom of the top box (4) is rotatably mounted with multiple equally spaced air regulating plates (7) via a rotating shaft. A sliding groove is provided on one side of the bottom of the top box (4), and a rack plate (15) is slidably mounted in the sliding groove. Multiple drive gears (16) are meshed on the outer side of the rack plate (15), and each drive gear (16) is fixedly connected to the rotating shaft of the corresponding air regulating plate (7). A rigid traction rope (33) is fixedly connected to one side of the rack plate (15), and the end of the rigid traction rope (33) away from the rack plate (15) is fixedly connected to the inner side of the movable cabinet door (3). The sliding of the movable cabinet door (3) moves the rack plate (15), which in turn drives the multiple drive gears (16) to rotate and drive the air regulating plates (7). The rack plate (15) is fixedly connected to a fixed plate (9) on the side away from the rigid traction rope (33). The outer surface of the fixed plate (9) is provided with a slanted groove (18). The rear side of the cabinet (1) is slidably installed with a drive shaft (17) in the horizontal direction. The rear side of the cabinet (1) is also fixedly connected with an installation cylinder (11). The installation cylinder (11) is sealed and slidably connected with a movable plate (28). The outer surface is connected to a connecting pipe one (13) and a connecting pipe three (26) in sequence along the axial direction. The end of the connecting pipe one (13) away from the installation cylinder (11) is connected to a spray pipe through a transport pump. The installation cylinder (11) is also equipped with a flow meter for detecting the flow rate of the spray liquid.

2. The exhaust gas treatment device for a laboratory fume hood according to claim 1, characterized in that, A movable block is fixedly installed at one end of the drive shaft (17) near the fixed plate (9). The movable block is slidably adapted to the inner wall of the inclined groove (18). The end of the drive shaft (17) away from the fixed plate (9) is fixedly connected to the outer center position of the movable plate (28). The fixed plate (9) is moved synchronously by the movement of the rack plate (15). The drive shaft (17) is driven to move horizontally by the sliding cooperation between the inclined groove (18) and the movable block. In turn, the movable plate (28) slides axially in the mounting cylinder (11) to realize the adjustment of the spray liquid pushing amount in the mounting cylinder (11).

3. The exhaust gas treatment device for a laboratory fume hood according to claim 1, characterized in that, A pump body (19) is fixedly connected to the rear side of the cabinet (1). The output end of the pump body (19) is fixedly connected to the end of the connecting pipe three (26) away from the installation cylinder (11). The input end of the pump body (19) is fixedly connected to the connecting pipe two (20). A storage tank (12) for storing spray liquid is also fixedly connected to the rear side of the cabinet (1). The end of the connecting pipe two (20) away from the pump body (19) is connected to the interior of the storage tank (12). The automatic extraction of spray liquid in the storage tank (12) and its delivery to the installation cylinder (11) are realized by starting and stopping the pump body (19).

4. The exhaust gas treatment device for a laboratory fume hood according to claim 1, characterized in that, Both the first (13) and the third (26) of the connecting pipe are fixedly equipped with control valves. The two control valves are independent on / off control structures, which can control the on / off and opening degree of the connecting pipes of the first (13) and the third (26) of the connecting pipe respectively. One end of the first (13) of the connecting pipe is connected to a spray pipe through a transport pump.

5. The exhaust gas treatment device for a laboratory fume hood according to claim 1, characterized in that, The cabinet (1) is fixedly connected to an installation box (2) on the outside. Two electric telescopic rods (14) are symmetrically installed on one side of the bottom of the installation box (2). Two fixed cylinders (6) are symmetrically fixedly connected on the other side of the bottom of the installation box (2). An installation groove (32) is opened inside the fixed cylinder (6). A rubber piston (29) is slidably connected inside the fixed cylinder (6) along the axial direction. A movable rod (27) is fixedly connected to the side of the rubber piston (29) away from the installation box (2). The end of the movable rod (27) away from the rubber piston (29) is fixedly connected to the output end of the electric telescopic rod (14). The movable rod (27) is driven to move back and forth by the extension and retraction of the electric telescopic rod (14), and the rubber piston (29) slides along the axial direction inside the fixed cylinder (6), so that a pressure difference is formed inside the fixed cylinder (6).

6. The exhaust gas treatment device for a laboratory fume hood according to claim 5, characterized in that, The outer surface of the fixed cylinder (6) is connected to the air inlet pipe (30) and the connecting pipe (5) in sequence along the axial direction. The end of the connecting pipe (5) away from the fixed cylinder (6) is connected to the interior of the mounting box (2), and multiple high-pressure nozzles are evenly arranged at the end of the connecting pipe (5) that extends into the mounting box (2). One-way valves (31) are fixedly installed inside the air inlet pipe (30) and the connecting pipe (5), and the internal conduction directions of the two one-way valves (31) are opposite. The one-way valve (31) in the air inlet pipe (30) is connected to the fixed cylinder (6), and the one-way valve (31) in the connecting pipe (5) is connected to the mounting box (2), so as to realize the one-way extraction and high-pressure injection of gas.

7. The exhaust gas treatment device for a laboratory fume hood according to claim 5, characterized in that, The installation box 1 (2) is symmetrically fixedly connected with two sets of installation plates (22). The bottom of each set of installation plates (22) is rotatably mounted with a movable shaft (23) through a bearing. A filter screen (21) is slidably sleeved on the outside of the movable shaft (23). The filter screen (21) is adapted to the internal channel of the installation box 1 (2). A sensor plate (25) is fixedly connected to the side of the installation plate (22) facing the filter screen (21). A trigger pressure plate adapted to the sensor plate (25) is provided on the outside of the filter screen (21). A reset spring (24) is also fixedly connected to the outside of the movable shaft (23). The end of the reset spring (24) away from the filter screen (21) is fixedly connected to the inside of the installation plate (22). The air pressure difference generated by the blockage on both sides of the filter screen (21) pushes the trigger pressure plate to move towards the sensor plate (25), thereby realizing the automatic detection of the blockage of the filter screen (21).

8. The exhaust gas treatment device for a laboratory fume hood according to claim 7, characterized in that, The trigger plate is an elastic metal plate, and the trigger plate is set on the exhaust gas inflow side of the filter (21). The elastic force of the reset spring (24) matches the preset air pressure threshold of the filter (21) blockage.

9. The exhaust gas treatment device for a laboratory fume hood according to claim 5, characterized in that, An exhaust channel (10) is fixedly connected to the side of the installation box (2) away from the cabinet (1). One end of the exhaust channel (10) is connected to the interior of the installation box (2), and the other end is used to connect to the fan and exhaust gas discharge pipe.

10. The exhaust gas treatment device for a laboratory fume hood according to claim 1, characterized in that, The inner wall of the top box (4) has a sliding groove that matches the rack plate (15) in a dovetail groove structure. The end of the rack plate (15) is a dovetail block structure that matches the dovetail groove. The outer side of the cabinet (1) is also fixedly connected to the second mounting box (8). The second mounting box (8) covers the outside of the pump body (19) and the storage box (12) to provide them with protection.

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