A waste gas extraction device and extraction system

Abstract

This invention discloses a waste gas extraction device and system, connected to a tank body, the tank body forming a sealed and hollow cavity. The tank body has an exhaust port communicating with the cavity. The device comprises: a sealing plate, a cover, a filter element, at least one first valve element, and an extraction pump. The sealing plate is positioned opposite the exhaust port and sealed to the tank body to block the exhaust port. The sealing plate has an exhaust hole and at least one air inlet hole. The cover is placed over the exhaust hole and at least one air inlet hole and connected to the sealing plate. The filter element is positioned opposite the exhaust hole and connected to the sealing plate to filter the gas. The first valve element is positioned opposite the air inlet hole and connected to the sealing plate to open or close the air inlet hole. The extraction pump is connected to the cover to introduce or discharge gas into or out of the cover body. This invention effectively solves the safety hazard caused by the inability of the extraction device to compensate for the negative pressure generated when materials are added or removed from the crushing tank.

Description

Technical Field

[0001] This invention relates to the field of waste gas treatment technology, specifically to a waste gas extraction device and extraction system. Background Technology

[0002] Waste gas treatment devices can be used to treat the industrial waste gas generated during battery recycling.

[0003] For example, Chinese utility model patent application number CN201710710979.5, entitled "A Waste Battery Crushing Device," includes a base, a crushing tank, a drive motor, and a crushing screw. A feed inlet is fixed to the top of the crushing tank near the right end, and a discharge outlet is fixed to the bottom of the crushing tank near the left end. A passageway is provided at the bottom of the crushing tank corresponding to the discharge outlet, and a mesh screen is fixed within the passageway. An exhaust port communicating with the inner cavity of the crushing tank is fixed to the left outer wall of the crushing tank. An exhaust device and an odor removal box are installed on the top of the base. The odor box is filled with deodorizing agent. The air inlet of the exhaust device is connected to a metal pipe that is connected to the left outer wall of the odor box, and the right outer wall of the odor box is connected to an exhaust pipe that is connected to the exhaust port. An air inlet connector is fixed at the bottom of the metal pipe, and the air inlet connector is connected to a vacuum counter-valve. This device can prevent irritating odors from spreading into the air. During use, the pressure change inside the crushing tank caused by the loading and unloading of materials can create negative pressure. However, the exhaust device cannot compensate for the pressure difference inside the crushing tank, which leads to a safety hazard.

[0004] Therefore, there is an urgent need for a waste gas extraction device and extraction system to solve the problem that existing technologies cannot compensate for the negative pressure generated when materials are loaded and unloaded in the crushing tank, which leads to safety hazards. Summary of the Invention

[0005] The purpose of this invention is to overcome the above-mentioned technical deficiencies and propose an exhaust gas extraction device and extraction system to solve the technical problem in the prior art that the exhaust device cannot compensate for the negative pressure generated when materials are loaded and unloaded in the crushing tank, thus causing safety hazards.

[0006] To achieve the above-mentioned technical objectives, the present invention adopts the following technical solution:

[0007] In a first aspect, the present invention provides an exhaust gas extraction device connected to a tank, wherein a sealed and hollow cavity is formed within the tank, and the tank has an exhaust port communicating with the cavity, comprising:

[0008] A sealing plate is disposed opposite to the exhaust port and is sealed to the groove body for sealing the exhaust port. The sealing plate has an exhaust hole and at least one air inlet hole.

[0009] A cover is provided over the exhaust port and at least one air inlet port, and is connected to the sealing plate;

[0010] A filter element is disposed opposite to the exhaust port and connected to the sealing plate for filtering gas;

[0011] At least one first valve component, disposed opposite to the air supply port and connected to the sealing plate, for opening or closing the air supply port; and

[0012] An air pump, connected to the cover, is used to introduce or expel gas into or from the cover.

[0013] In some embodiments, the air pump has a first state of drawing gas out of the cover and a second state of drawing gas into the cover. In the first state, the interior of the cover is connected to the cavity via the exhaust port and the filter. In the second state, the interior of the cover is connected to the cavity via at least one of the air inlet ports.

[0014] In some embodiments, the first valve component includes a rotating shaft, a valve plate, and a torsion spring. The rotation axis of the rotating shaft is perpendicular to the axis of the air inlet and is rotatably connected to the sealing plate. The valve plate is positioned relative to the air inlet and is connected to the rotating shaft. After the valve plate rotates relative to the sealing plate, it can open or close the air inlet. One end of the torsion spring is connected to the rotating shaft, and the other end is connected to the sealing plate. It is used to drive the rotating shaft and the valve plate to rotate and then automatically reset.

[0015] In some embodiments, the first valve component further includes a first sleeve and two connecting blocks. The first sleeve is coaxially arranged with the air inlet and connected to one side wall of the sealing plate opposite to the cavity. The two connecting blocks are spaced apart from each other and are both connected to the first sleeve. The two ends of the rotating shaft are rotatably connected to the two connecting blocks respectively. One end of the torsion spring is connected to the rotating shaft and the other end is connected to one of the connecting blocks.

[0016] In some embodiments, the number of air inlet holes on the sealing plate is multiple, and the multiple air inlet holes are symmetrically distributed around the center point of the exhaust hole. The number of first valve components in the exhaust gas extraction device is multiple, and the valve plate is provided in one-to-one correspondence with the air inlet holes and is rotatably connected to the sealing plate.

[0017] In some embodiments, the filter element includes a second sleeve and filter cotton. The second sleeve is disposed on one side wall of the sealing plate opposite to the cover and is coaxially disposed with the air inlet hole. The filter cotton is uniformly filled in the second sleeve.

[0018] In some embodiments, the filter element further includes a connecting portion, which includes a first connecting flange, a second connecting flange, and a plurality of fastening connecting portions. The first connecting flange is connected to a side wall of the sealing plate opposite to the cover, the second connecting flange is disposed opposite to the first flange and connected to the second sleeve, and the plurality of fastening connecting portions are connected to both the first connecting flange and the second connecting flange.

[0019] In some embodiments, the cover is tubular and has a large-diameter section and a small-diameter section, with the large-diameter section of the cover positioned closer to the sealing plate than the small-diameter section, and the second sleeve being housed within the large-diameter section of the cover.

[0020] In some embodiments, the small-diameter section of the hood is provided with an air outlet, and the exhaust gas extraction device further includes a second valve component. The second valve component includes a mounting block, a baffle, a sealing part, and a driving part. The mounting block is disposed opposite to the air outlet and connected to the inner wall of the small-diameter section of the hood for sealing the air outlet. The mounting block is provided with a communicating hole connected to the air outlet. The baffle is disposed opposite to the communicating hole and is rotatably connected to the baffle. The sealing part is disposed between the mounting block and the baffle for sealing the baffle to the mounting block. The driving part is connected to the hood and the baffle for driving the baffle to rotate relative to the mounting block to open or close the communicating hole.

[0021] Secondly, the present invention also provides an exhaust gas extraction system, comprising: the tank and an exhaust gas extraction device as described in any one of the above.

[0022] Compared with the prior art, the beneficial effects of the exhaust gas extraction device and extraction system provided by the present invention include: sealing the exhaust port by setting a sealing plate and sealing the tank body, wherein the sealing plate has an exhaust hole and at least one air inlet hole, the cover body covers the exhaust hole and at least one air inlet hole and is connected to the sealing plate, the filter element is arranged opposite to the exhaust hole, at least one first valve element is arranged opposite to the air inlet hole and connected to the sealing plate, and the extraction pump is connected to the cover body for introducing or discharging gas into or out of the cover body. Compared to existing technologies, this method connects the cavity to the external environment by installing a vacuum pump. When gas needs to be discharged from the cavity, the first valve closes, and the gas passes through the filter to form filtration and exhaust. The vacuum pump then draws the gas out of the cavity and the enclosure. When gas needs to be added to the cavity, the first valve opens, and gas can only pass through the air inlet. The vacuum pump then fills the cavity with gas from the external environment. This achieves communication between the cavity and the external environment, thereby compensating for the negative pressure formed inside the cavity. This solves the safety hazard problem caused by the inability of the ventilation device to compensate for the negative pressure generated when materials are loaded and unloaded in the crushing tank in existing technologies. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the structure of a waste gas extraction device connected to a tank according to an embodiment of the present invention;

[0024] Figure 2 This is a cross-sectional view of the connection between a waste gas extraction device and a tank, provided in an embodiment of the present invention.

[0025] Figure 3 It is along Figure 2 Enlarged view of point A in the middle;

[0026] Figure 4 This is a cross-sectional structural diagram showing the connection between the small-diameter section of the cover and the second valve component provided in an embodiment of the present invention.

[0027] Explanation of reference numerals in the attached figures:

[0028] Tank 1;

[0029] Sealing plate 2;

[0030] Cover 3;

[0031] Filter element 4;

[0032] Second sleeve 41;

[0033] Filter cotton 42;

[0034] Connecting part 43;

[0035] First valve component 5;

[0036] Rotating shaft 51;

[0037] Valve plate 52;

[0038] Torsion spring 53;

[0039] First sleeve 54;

[0040] Connector block 55;

[0041] 6 air pumps;

[0042] Second valve component 7;

[0043] Install block 71;

[0044] baffle 72;

[0045] Sealing part 73;

[0046] Drive unit 74. Detailed Implementation

[0047] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0048] To address the technical problem in existing technologies where the exhaust device cannot compensate for the negative pressure generated during material loading and unloading in the crushing tank, thus posing a safety hazard, this invention provides an exhaust gas extraction device and extraction system. This system enables communication between the internal cavity of the tank 1 and the external environment, thereby compensating for the negative pressure generated during material loading and unloading in the crushing tank and preventing safety hazards.

[0049] It should be noted that the exhaust gas extraction device and extraction system described in this invention are used in, but not limited to, the field of exhaust gas treatment technology. For ease of explanation, this invention will only use the application of the exhaust gas extraction device and extraction system in the field of exhaust gas treatment technology as an example for explanation. The principle of the exhaust gas extraction device and extraction system applied to other types of equipment is essentially the same as the principle applied to the field of exhaust gas treatment technology, and will not be described in detail here.

[0050] Please see Figures 1 to 4 , Figure 1 , Figure 2 This is a schematic diagram of the structure of an exhaust gas extraction device and extraction system in one embodiment of the present invention. The exhaust gas extraction device is connected to a tank 1, and a sealed and hollow cavity is formed inside the tank 1. The tank 1 has an exhaust port that communicates with the cavity. The device includes: a sealing plate 2, a cover 3, a filter element 4, at least one first valve element 5, and an extraction pump 6. The sealing plate 2 is disposed opposite to the exhaust port and is sealed to the tank 1 to block the exhaust port. The sealing plate 2 has an exhaust hole and at least one air inlet hole. The cover 3 covers the exhaust hole and at least one air inlet hole and is connected to the sealing plate 2. The filter element 4 is disposed opposite to the exhaust hole and is connected to the sealing plate 2 to filter the gas. At least one first valve element 5 is disposed opposite to the air inlet hole and is connected to the sealing plate 2 to open or close the air inlet hole. The extraction pump 6 is connected to the cover 3 to introduce or discharge gas into the cover 3.

[0051] In this device, such as Figure 2 , Figure 3 As shown, the exhaust port is sealed by setting a sealing plate 2 and sealing it to the tank body 1. The sealing plate 2 has an exhaust hole and at least one air inlet hole. The cover body 3 covers the exhaust hole and at least one air inlet hole and is connected to the sealing plate 2. The filter element 4 is set opposite to the exhaust hole. At least one first valve element 5 is set opposite to the air inlet hole and is connected to the sealing plate 2. The air pump 6 is connected to the cover body 3 and is used to introduce or discharge gas into the cover body 3.

[0052] Compared to existing technologies, by setting up an air pump 6 to connect the cavity to the external environment, when it is necessary to discharge gas from the cavity, the first valve 5 is closed, and the gas passes through the filter 4 to form filtration and exhaust. The air pump 6 draws the gas out of the cavity and the cover 3. When it is necessary to replenish gas into the cavity, the first valve 5 is opened, and the gas can only pass through the air replenishment hole. The air pump 6 fills the cavity with gas from the external environment. This enables communication between the cavity and the external environment, thereby compensating for the negative pressure formed in the cavity. This solves the problem in existing technologies where the ventilation device cannot compensate for the negative pressure generated when materials are loaded and unloaded in the crushing tank, which leads to safety hazards.

[0053] Furthermore, in this device, the tank 1 is a crushing tank or crushing trough for equipment used for crushing and dismantling lithium batteries, and a tank 1 for the production of ternary cathode materials, etc. The tank 1 can realize the feeding or unloading of materials. This is a conventional setting known to those skilled in the art, and will not be described in detail here.

[0054] In this embodiment, the air pump 6 has a first state of extracting gas out of the cover 3 and a second state of drawing gas into the cover 3. In the first state, the interior of the cover 3 is connected to the cavity through the exhaust port and the filter 4. In the second state, the interior of the cover 3 is connected to the cavity through at least one air inlet port.

[0055] When material is conveyed out of the tank 1 or added to the tank 1, the pressure inside the tank 1 will change. Therefore, the pressure inside the tank 1 can be compensated and balanced by switching between the first state and the second state.

[0056] In this embodiment, the first valve component 5 includes a rotating shaft 51, a valve plate 52, a torsion spring 53, a first sleeve 54, and two connecting blocks 55.

[0057] The rotating shaft 51 is perpendicular to the axis of the air inlet and is rotatably connected to the sealing plate 2. The valve plate 52 is positioned relative to the air inlet and is connected to the rotating shaft 51. The valve plate 52 can open or close the air inlet after rotating relative to the sealing plate 2. One end of the torsion spring 53 is connected to the rotating shaft 51 and the other end is connected to the sealing plate 2. It is used to drive the rotating shaft 51 and the valve plate 52 to rotate and then automatically reset.

[0058] The rotating shaft 51 is used to drive the valve plate 52 to rotate relative to the sealing plate 2, and the torsion spring 53 is used to automatically reset after the rotating shaft 51 and the valve plate 52 rotate.

[0059] Furthermore, the torsion spring 53 here is a common and readily available device on the market, and the valve plate 52 here is a high-strength, lightweight plate that can form a sealed connection with the air supply hole. Further details will not be provided here.

[0060] One implementation method is, for example Figure 3 As shown, the first sleeve 54 is coaxially arranged with the air inlet and connected to one side wall of the sealing plate 2 opposite to the cavity. Two connecting blocks 55 are spaced apart from each other and are both connected to the first sleeve 54. The two ends of the rotating shaft 51 are rotatably connected to the two connecting blocks 55 respectively. One end of the torsion spring 53 is connected to the rotating shaft 51 and the other end is connected to a connecting block 55.

[0061] The connecting block 55 and the first sleeve 54 connect the rotating shaft 51 and the valve plate 52 relative to the sealing plate 2.

[0062] Furthermore, in the first state, the elastic restoring force generated by the torsion spring 53 causes the valve plate 52 and the first sleeve 54 to form a sealed connection, preventing gas from entering the interior of the shroud 3 through the exhaust port from the cavity. The gas in the cavity can only enter the interior of the shroud 3 through the exhaust port and the filter element 4, thus enabling the treatment of waste gas. At the same time, in the second state, the vacuum pump 6 introduces external ambient gas into the shroud 3, in which the gas cannot enter the cavity in reverse through the filter element 4 and the exhaust port. Therefore, the pressure acting on the valve plate 52 overcomes the restoring force generated by the torsion spring 53, and the valve plate 52 rotates in a direction away from the first sleeve 54, opening the air inlet and allowing the external ambient gas in the shroud 3 to enter the cavity.

[0063] As another implementation method, such as Figure 2 As shown, there are multiple air inlet holes on the sealing plate 2, which are symmetrically distributed along the exhaust hole at the center point. There are multiple first valve components 5 in the exhaust gas extraction device, and the valve plate 52 is set one-to-one with the air inlet holes and is rotatably connected to the sealing plate 2.

[0064] Multiple air inlets can improve the stability of pressure compensation and enhance the stability of the device during operation.

[0065] In this embodiment, the filter element 4 includes a second sleeve 41, filter cotton 42, and a connecting part 43.

[0066] The second sleeve 41 is located on one side wall of the sealing plate 2 opposite to the cover 3 and is coaxially arranged with the air replenishment hole. The filter cotton 42 is evenly filled in the second sleeve 41.

[0067] The filter cotton 42 is connected to the exhaust port via the second sleeve 41 and is located on the side of the sealing plate 2 away from the valve plate 52.

[0068] Furthermore, the filter cotton 42 can effectively filter impurities and particulate matter in the air, thereby providing cleaner and healthier air to users. This is a conventional setting known to those skilled in the art and will not be described in detail here.

[0069] One implementation method is, for example Figure 3As shown, the connecting part 43 includes a first connecting flange, a second connecting flange, and a plurality of fastening connecting parts 43. The first connecting flange is connected to one side wall of the sealing plate 2 opposite to the cover 3. The second connecting flange is disposed opposite to the first flange and connected to the second sleeve 41. The plurality of fastening connecting parts 43 are connected to both the first connecting flange and the second connecting flange.

[0070] The second sleeve 41 and the sealing plate 2 are connected by a first connecting flange, a second connecting flange and multiple fastening connection parts 43 to achieve a detachable sealing connection.

[0071] Furthermore, the first connecting flange, the second connecting flange, and the multiple fastening connections 43 are all common and readily available equipment on the market. This is a conventional setup known to those skilled in the art, and will not be described in detail here.

[0072] As another implementation method, such as Figure 1 , Figure 2 As shown, the cover 3 is tubular and has a large diameter section and a small diameter section. The large diameter section of the cover 3 is positioned closer to the sealing plate 2 than the small diameter section. The second sleeve 41 is built into the large diameter section of the cover 3.

[0073] Specifically, the hood 3 in this device has a large-diameter section and a small-diameter section, which can effectively treat and discharge waste gas.

[0074] In this embodiment, as Figure 2 , Figure 4 As shown, the small-diameter section of the hood 3 has an air outlet. The exhaust gas extraction device also includes a second valve component 7, which includes a mounting block 71, a baffle 72, a sealing part 73, and a driving part 74. The mounting block 71 is positioned opposite the air outlet and connected to the inner wall of the small-diameter section of the hood 3 to block the air outlet. The mounting block 71 has a connecting hole that communicates with the air outlet. The baffle 72 is positioned opposite the connecting hole and is rotatably connected to the baffle 72. The sealing part 73 is positioned between the mounting block 71 and the baffle 72 to seal the baffle 72 to the mounting block 71. The driving part 74 is connected to the hood 3 and the baffle 72 to drive the baffle 72 to rotate relative to the mounting block 71 to open or close the connecting hole.

[0075] The valve structure, consisting of mounting block 71, baffle 72, sealing part 73, and driving part 74, allows baffle 72 to rotate relative to mounting block 71 under the drive of driving part 74. This adjusts the opening size of the connecting hole, thereby regulating the airflow and controlling the flow speed and volume of air or gas within the system. By adjusting the valve's opening degree, the airflow in the system can be effectively regulated to meet the needs of different operating conditions.

[0076] Specifically, in this device, the mounting block 71 has a receiving groove that communicates with the connecting hole. The plane of the receiving groove is perpendicular to the axis of the connecting hole. The sealing part 73 is sealed between the inner wall of the receiving groove and the baffle 72. The driving part 74 is a motor that is common in the market and easy to purchase. After the output shaft of the motor rotates, it can drive the baffle 72 to rotate relative to the mounting block 71, thereby adjusting the opening size of the connecting hole.

[0077] In this embodiment, the present invention also provides an exhaust gas extraction system, including: a tank 1 and an exhaust gas extraction device.

[0078] To better understand this invention, the technical solution is described in detail below with reference to the figures: A sealing plate 2 is sealed to the tank 1 to block the exhaust port. The sealing plate 2 has an exhaust hole and at least one air inlet hole. A cover 3 covers the exhaust hole and at least one air inlet hole and is connected to the sealing plate 2. A filter element 4 is positioned opposite the exhaust hole, and at least one first valve element 5 is positioned opposite the air inlet hole and connected to the sealing plate 2. A vacuum pump 6 is connected to the cover 3 for introducing or discharging gas into or out of the cover 3. Compared to the prior art, by connecting the cavity to the external environment through the vacuum pump 6, when it is necessary to discharge gas from the cavity, the first valve element 5 is closed, and the gas passes through the filter element 4 to form filtration and exhaust. The vacuum pump 6 draws the gas out of the cavity and the cover 3. When it is necessary to replenish gas into the cavity, the first valve element 5 is opened, and the gas can only pass through the air inlet hole. The vacuum pump 6 fills the cavity with gas from the external environment, thereby achieving communication between the cavity and the external environment and compensating for the negative pressure formed in the cavity.

[0079] In the specific working process of the present invention, when material is added into the tank 1, the air in the tank 1 needs to be discharged. At this time, in the first state, the elastic restoring force generated by the torsion spring 53 causes the valve plate 52 and the first sleeve 54 to form a sealed connection. The gas cannot enter the interior of the cover 3 from the cavity through the exhaust hole. The gas in the cavity can only enter the interior of the cover 3 through the exhaust hole and the filter 4, thereby forming the treatment of waste gas.

[0080] Furthermore, when the tank 1 conveys materials outward, it will cause a negative pressure to form inside the tank 1. Air needs to be replenished inside the tank 1. At this time, in the second state, the air pump 6 introduces external ambient gas into the cover 3. The gas cannot pass through the filter 4 and the exhaust port to enter the cavity in reverse. Therefore, the pressure acting on the valve plate 52 overcomes the restoring force generated by the torsion spring 53. The valve plate 52 rotates in the direction away from the first sleeve 54, the air replenishment port opens, and the external ambient gas inside the cover 3 can enter the cavity.

[0081] Furthermore, the rotation of the motor's output shaft drives the baffle 72 to rotate relative to the mounting block 71, thereby adjusting the opening size of the connecting hole. This controls the flow rate and volume of air or gas within the system. By adjusting the valve's opening degree, the airflow in the system can be effectively regulated to meet the needs of different operating conditions.

[0082] This device, through the aforementioned structure, can solve the problem in the prior art where the ventilation device cannot compensate for the negative pressure generated when materials are fed into and out of the crushing tank, thus causing safety hazards.

[0083] The specific embodiments of the present invention described above do not constitute a limitation on the scope of protection of the present invention. Any other corresponding changes and modifications made in accordance with the technical concept of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A waste gas extraction device, connected to a tank, wherein a sealed and hollow cavity is formed within the tank, and the tank has an exhaust port communicating with the cavity, characterized in that, include: A sealing plate is disposed opposite to the exhaust port and is sealed to the groove body for sealing the exhaust port. The sealing plate has an exhaust hole and at least one air inlet hole. A cover is provided over the exhaust port and at least one air inlet port, and is connected to the sealing plate; A filter element is disposed opposite to the exhaust port and connected to the sealing plate for filtering gas; At least one first valve component is disposed opposite to the air supply port and connected to the sealing plate for opening or closing the air supply port; as well as An air pump, connected to the cover, is used to introduce or expel gas into or from the cover. The first valve component includes a rotating shaft, a valve plate, and a torsion spring. The rotation axis of the rotating shaft is perpendicular to the axis of the air inlet and is rotatably connected to the sealing plate. The valve plate is positioned relative to the air inlet and is connected to the rotating shaft. After the valve plate rotates relative to the sealing plate, it can open or close the air inlet. One end of the torsion spring is connected to the rotating shaft and the other end is connected to the sealing plate, and it is used to drive the rotating shaft and the valve plate to rotate and then automatically reset.

2. The waste gas extraction device according to claim 1, characterized in that, The air pump has a first state of drawing gas out of the cover and a second state of drawing gas into the cover. In the first state, the interior of the cover is connected to the cavity through the exhaust port and the filter. In the second state, the interior of the cover is connected to the cavity through at least one of the air inlet ports.

3. The waste gas extraction device according to claim 1, characterized in that, The first valve component further includes a first sleeve and two connecting blocks. The first sleeve is coaxially arranged with the air inlet and connected to one side wall of the sealing plate opposite to the cavity. The two connecting blocks are spaced apart from each other and are both connected to the first sleeve. The two ends of the rotating shaft are rotatably connected to the two connecting blocks respectively. One end of the torsion spring is connected to the rotating shaft and the other end is connected to one of the connecting blocks.

4. The waste gas extraction device according to claim 3, characterized in that, The sealing plate has multiple air inlet holes, which are symmetrically distributed around the exhaust hole at the center point. The exhaust gas extraction device has multiple first valve components, and the valve plate is provided in one-to-one correspondence with the air inlet holes and is rotatably connected to the sealing plate.

5. The waste gas extraction device according to claim 4, characterized in that, The filter element includes a second sleeve and filter cotton. The second sleeve is disposed on one side wall of the sealing plate opposite to the cover and is coaxially arranged with the air inlet hole. The filter cotton is evenly filled in the second sleeve.

6. The waste gas extraction device according to claim 5, characterized in that, The filter element further includes a connecting portion, which includes a first connecting flange, a second connecting flange, and a plurality of fastening connecting portions. The first connecting flange is connected to one side wall of the sealing plate opposite to the cover body. The second connecting flange is disposed opposite to the first flange and connected to the second sleeve. The plurality of fastening connecting portions are connected to both the first connecting flange and the second connecting flange.

7. The waste gas extraction device according to claim 6, characterized in that, The cover is tubular and has a large-diameter section and a small-diameter section. The large-diameter section of the cover is positioned closer to the sealing plate than the small-diameter section, and the second sleeve is built into the large-diameter section of the cover.

8. The waste gas extraction device according to claim 7, characterized in that, The small-diameter section of the hood has an air outlet. The exhaust gas extraction device also includes a second valve component, which includes a mounting block, a baffle, a sealing part, and a driving part. The mounting block is positioned opposite the air outlet and connected to the inner wall of the small-diameter section of the hood to block the air outlet. The mounting block has a connecting hole that communicates with the air outlet. The baffle is positioned opposite the connecting hole and is rotatably connected to the baffle. The sealing part is positioned between the mounting block and the baffle to seal the baffle to the mounting block. The driving part is connected to the hood and the baffle to drive the baffle to rotate relative to the mounting block, thereby opening or closing the connecting hole.

9. A waste gas extraction system, characterized in that, include: The tank and the exhaust gas extraction device as described in any one of claims 1-8.

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