Waste gas filtering and purifying device for laboratory ventilation

Abstract

The invention relates to the technical field of gas filtration, in particular to a waste gas filtration and purification device for laboratory ventilation, which comprises a filter cartridge, a purification bin is arranged in the filter cartridge, a movable inner groove and a filter element are further arranged on the outer side of the purification bin in an inner wall cavity of the filter cartridge, the filter element is arranged in an inner cavity of the purification bin, and the filter element comprises at least three filter layers. Each filter layer comprises a filter plate, the outer edge of the filter plate is provided with a sealing ring, the bottom of the filter plate is provided with a first rack and a transposition mechanism, the transposition mechanism is arranged in an inner cavity of the movable inner groove, the primary filter layer, the adsorption layer and the fine filter layer are driven by the transposition mechanism to move in the filter bin, and the single filter layer is temporarily stored by means of the filter bin. After the positions of the other two filter layers are adjusted, the temporary storage filter layer is put back, so that the sequence of the filter layers is flexibly switched, the problem that the adaptability and purification effect of the purification device to waste gases with different characteristics are limited is effectively solved, the adaptation range of the purification device is greatly widened, and the service life of the filter layers is prolonged.

Description

Technical Field

[0001] This invention relates to the field of gas filtration technology, specifically to a waste gas filtration and purification device for laboratory ventilation. Background Technology

[0002] During experiments such as chemical synthesis, semiconductor chip fabrication, and biological agent development, laboratories generate various harmful waste gases, including highly viscous waste gases containing resin volatiles and oil mists, high-humidity misty waste gases associated with distillation experiments, and waste gases containing pollutants and fine particles. If these waste gases are emitted directly without treatment, they will not only adhere to the surfaces of experimental equipment, affecting experimental accuracy, but also endanger the respiratory health of laboratory personnel and damage the internal environment of the laboratory.

[0003] Existing laboratory ventilation exhaust gas filtration and purification devices have significant technical defects. The core problem lies in the fact that the filter layers (pre-filter, adsorption layer, fine filter) adopt a fixed filtration sequence (mostly "pre-filter → adsorption layer → fine filter"), which cannot be dynamically adjusted according to the characteristics of the exhaust gas. For fine sticky particles, the pre-filter layer comes into contact with the exhaust gas first under the fixed sequence. Fine sticky particles can penetrate the pre-filter layer and stick to the pores of the adsorption layer, which can easily lead to increased clogging of the adsorption layer and reduce the adsorption effect of the adsorption layer on pollutants. When the exhaust gas contains high humidity, the high humidity exhaust gas passes through the pre-filter layer first, causing the pre-filter layer to become damp and prone to clogging in subsequent use. Summary of the Invention

[0004] The purpose of this invention is to provide a laboratory ventilation exhaust gas filtration and purification device to solve the problems mentioned in the background art.

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

[0006] A laboratory ventilation exhaust gas filtration and purification device includes a filter cylinder with a purification chamber inside, and a movable inner groove is also provided in the inner wall cavity of the filter cylinder outside the purification chamber.

[0007] A filter element is disposed in the inner cavity of the purification chamber. The filter element includes at least three filter layers, each filter layer including a filter plate. A sealing ring is provided on the outer edge of the filter plate, and a first toothed rack is provided on the bottom of the filter plate.

[0008] The switching mechanism is located in the inner cavity of the movable inner groove. The switching mechanism includes a switching ring, an air supply component, a second rack, and a shifting gear, which are the same number of filter layers and correspond to each other. The shifting gear rotates to drive the second rack to move vertically, which drives the switching ring to drive the filter layers to move vertically in the purification chamber in sync, thereby realizing the adjustment of the filter layer sequence. The air supply component is located below the switching ring and is used to inject air into the sealing ring after the filter layers have moved.

[0009] A filter replacement bin is arranged on one side of the filter cartridge and used for temporarily storing the filter layer to be adjusted or replaced.

[0010] Preferably, the filter replacement bin is provided with a transposition gear engaged with the first rack. The transposition gear is driven by the first rack to drive the filter layer to enter or exit the filter replacement bin. An electric hatch is arranged at the entrance of the filter replacement bin to control the opening and closing of the filter replacement bin, thereby preventing the leakage of uncleaned exhaust gas.

[0011] Preferably, the air supplement assembly comprises an air supplement bin, two air production bins, a gas conveying pipe and a gas transmission pipe. The two air production bins are arranged on the upper and lower sides of the air supplement bin, and the side away from the air supplement bin is inclined. The air supplement bin receives the gas from the air production bin or inhales the air outside through the gas transmission pipe, and then supplies the gas to the sealing ring or discharges the gas in the sealing ring through the gas conveying pipe, thereby controlling the inflation and deflation of the sealing ring.

[0012] Preferably, the inner side of the transposition ring is provided with a plurality of electromagnets, and the outer side of the filter plate is provided with a plurality of magnets. The corresponding surfaces of the electromagnets and the magnets are attracted to each other.

[0013] Preferably, the end of the first rack away from the filter replacement bin is connected with a linkage block. The linkage block is connected with a magnet and connected to the outer side of the filter plate through a spring. When the attraction between the electromagnet and the magnet is disconnected, the spring rebounds to drive the linkage block to move, so that the end of the first rack extends into the filter replacement bin, thereby providing transmission connection for the filter layer to enter the filter replacement bin.

[0014] Preferably, each transposition ring is provided with two segments and connected through a spring. The contact position of the second rack and the transposition ring is provided with an embedded groove. When the electromagnet and the magnet are attracted, the two segments of the transposition ring are close to each other and connected through the embedded groove. When the attraction disappears, the two segments of the transposition ring are separated and disconnected from the embedded groove, thereby avoiding blocking the movement of other transposition rings.

[0015] Preferably, the gas transmission pipe is a tapered structure, and the inner diameter gradually increases from one end to the other end. The end with smaller inner diameter is provided with a sealing plate connected through a spring. The gas transmission pipe connected with the air supplement bin has a smaller inner diameter at the end connected with the air supplement bin, and the gas transmission pipe for inhaling the air outside has a smaller inner diameter at the end penetrating through the outer shell of the filter cartridge.

[0016] Preferably, the gas conveying pipe comprises an input pipe. A gas guide groove is arranged at one end of the inner cavity of the input pipe. A gas guide plate connected through a spring is arranged at the other end of the inner cavity of the input pipe.

[0017] Preferably, the outer side of the sealing ring is provided with a gas supplement pipe connected through a spring. The gas supplement pipe corresponds to the position of the input pipe. When the filter layer moves to the installation position, the spring rebounds to make the gas supplement pipe butt joint with the input pipe, thereby providing a channel for the inflation and deflation of the sealing ring.

[0018] Preferably, the gas supply pipe further comprises a gas exhaust pipe, and an electromagnetic valve is arranged in the inner cavity of the gas exhaust pipe.

[0019] Compared with the prior art, the present application has the following advantages:

[0020] 1. In the present application, the primary filter layer, the adsorption layer and the fine filter layer are driven to move in the filter chamber by the transposition mechanism, and a single filter layer is temporarily stored in the filter chamber, and after the positions of the remaining two filter layers are adjusted, the temporarily stored filter layer is put back, so that the filter layers can be flexibly switched in sequence, the problem that the adaptability of the purification device to different characteristic waste gases and the purification effect are limited is effectively solved, the adaptation range of the purification device is greatly improved, and the service life of the filter layer is improved.

[0021] 2. In addition, by means of the transposition mechanism, the filter layer to be replaced is moved to the filter chamber, and the transposition mechanism moves the corresponding filter layer in a directional manner, without the need to disassemble other intact filter layers, so that single-layer quick replacement of the failed filter layer can be realized, and the situation that the high-value adsorption material that is not failed is simultaneously eliminated when the "integral filter cartridge" is replaced is avoided, the cost of consumables is greatly reduced, and at the same time, the corresponding filter layer can be moved by the transposition mechanism, so that single-layer quick replacement of the failed filter layer can be realized.

[0022] 3. On the basis of the above structure, in order to solve the problem of sealing failure during the movement of the filter layer, before the movement of the filter layer, the gas bag is deflated to extract the gas in the sealing seat, so as to ensure the smooth movement of the filter layer, and during the movement of the filter layer, the gas bag is inflated, the gas is injected into the sealing seat after the position of the filter layer is fixed, so that the sealing seat is tightly attached to the filter chamber, and the leakage of untreated waste gas through the gap between the cylinder walls is avoided, and the subsequent filter plate is prevented from being damaged. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 Fig. 1 is a schematic view of the front structure of the filter purification device in the present application;

[0024] Figure 2 Fig. 2 is a schematic view of the plan structure of the filter purification device in the present application;

[0025] Figure 3 Fig. 3 is a partial cross-sectional view of the filter cartridge in the present application, and shows the filter core;

[0026] Figure 4 Fig. 4 is a schematic view of the cross section of the filter cartridge in the present application;

[0027] Figure 5 Fig. 5 is a schematic view of the overall structure and a partial enlarged view of the filter layer in the present application; and shows the connecting block and the air supplementing pipe;

[0028] Figure 6 Fig. 6 is a schematic view of the overall structure of the transposition mechanism in the present application;

[0029] Figure 7 Figure for the moving track of the filter core in the purification bin in the application;

[0030] Figure 8 Figure for the overall structure of the transposition ring in the application, and shows the second rack;

[0031] Figure 9 Figure for the overall structure of the air supplement assembly in the application;

[0032] Figure 10 Figure for the overall structure of the air transmission pipe in the application;

[0033] Figure 11 Figure for the overall structure of the air transmission pipe in the application.

[0034] In the figure: 100, filter cylinder; 110, purification bin; 120, movable inner groove;

[0035] 200, filter core; 210, filter layer; 210a, primary filter layer; 210b, adsorption layer; 210c, fine filter layer; 211, filter plate; 212, sealing ring; 213, magnet; 214, first rack; 215, linkage block; 216, air supplement pipe;

[0036] 300, transposition mechanism; 310, transposition ring; 311, electromagnet; 320, air supplement assembly; 321, air supplement bin; 322, gas production bin; 323, air transmission pipe; 3231, input pipe; 3232, air release pipe; 3233, air guide groove; 3234, air guide plate; 3235, electromagnetic valve; 324, air transmission pipe; 3241, sealing plate; 330, second rack; 331, fitting groove; 340, transposition gear;

[0037] 400, filter replacement bin; 410, transposition gear; 420, electric cabin door. DETAILED DESCRIPTION

[0038] In order for those skilled in the art to better understand the technical solutions in the application, the technical solutions in the embodiments of the application will be described clearly and completely below. Obviously, the described embodiments are only some of the embodiments of the application, but not all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the application.

[0039] In order to better understand the above technical solutions, the above technical solutions will be described in detail below in combination with the drawings in the specification and specific embodiments.

[0040] As Figure 1 and Figure 2As shown, this embodiment discloses a laboratory ventilation exhaust gas filtration and purification device, including a filter cylinder 100, a filter element 200, a switching mechanism 300, and a filter exchange chamber 400. The filter element 200 is disposed in a purification chamber 110 opened within the inner cavity of the filter cylinder 100, and the filter element 200 includes three filter layers 210, such as... Figures 3-4 As shown, the switching mechanism 300 is disposed in the movable inner groove 120 opened in the inner wall cavity of the filter cylinder 100, so that the switching mechanism 300 is located outside the filter element 200. The filter layer 210 is moved by controlling the switching mechanism 300. The filter replacement chamber 400 is disposed on one side of the filter cylinder 100 and is connected to the inner cavity of the purification chamber 110. When a filter layer 210 moves to the filter replacement chamber 400, the corresponding filter layer 210 can be moved into the filter replacement chamber 400.

[0041] Furthermore, the existing purification device is equipped with multiple filter layers 210, including but not limited to a pre-filter layer 210a, an adsorption layer 210b, and a fine filter layer 210c. The pre-filter layer 210a is responsible for intercepting large particulate impurities, the adsorption layer 210b is used to treat gaseous pollutants, and the fine filter layer 210c is used to intercept fine particles. The exhaust gas is filtered and purified by passing through multiple filter layers. However, the order in which the exhaust gas passes through each filter layer is fixed and cannot be dynamically adjusted according to the characteristics of the exhaust gas.

[0042] like Figure 6 As shown, the shifting mechanism 300 includes a shifting ring 310, a second rack 330, and a shifting gear 340. A power source drives the shifting gear 340, which is located at the bottom end of the second rack 330, to rotate, thereby moving the shifting ring 310 located on one side of the second rack 330. Figure 5 As shown, the filter layer 210 includes a filter plate 211 and magnets 213. Multiple magnets 213 are disposed on the outer side of the filter plate 211, such as... Figure 8 As shown, the inner side of the transposition ring 310 is provided with the same number of electromagnets 311 as the magnets 213, and the number of transposition rings 310 is also set to three, each corresponding to one of the three filter layers 210. When the electromagnets 311 are energized, they generate magnetic force with the magnets 213 and attract each other. The second rack 330 drives the transposition rings 310 to move, causing the filter layers 210 to move along the inner cavity of the purification chamber 110. Figure 7 As shown, when it is necessary to move the pre-filter layer 210a to the bottom of the filter layer, the pre-filter layer 210a is moved to the filter exchange chamber 400 and transferred to the interior of the filter exchange chamber 400. At this time, the remaining adsorption layer 210b and fine filter layer 210c are moved to the top of the filter exchange chamber 400, and the pre-filter layer 210a is transferred from the inner cavity of the filter exchange chamber 400 to the inner cavity of the purification chamber 110, thus completing the position switch and moving the pre-filter layer 210a to the bottom of each filter layer.

[0043] The device is adapted to different properties of waste gas by random switching of the filter layer 210 position. If the laboratory waste gas contains fine sticky particles (such as resin droplets, paint waste gas), in the conventional "primary filter layer 210a→adsorption layer 210b→fine filter layer 210c" sequence, fine sticky particles will penetrate the primary filter layer 210a and stick in the pores of the adsorption layer 210b, causing the adsorption layer 210b to be easily blocked and the service life to be greatly reduced. At this time, adjust to "primary filter layer 210a→fine filter layer 210c→adsorption layer 210b", first intercept fine sticky particles through the fine filter layer 210c, and then let clean waste gas enter the adsorption layer 210b. The pores of the adsorption layer 210b are not blocked, and the service life is improved. If the waste gas contains high humidity waste gas (such as solvent distillation, wet heat reaction experiment), the high humidity waste gas passes through the primary filter layer 210a, causing the primary filter layer 210a to be damp and prone to blockage in subsequent use. The waste gas produced by distillation and wet heat reaction contains almost no dust and solid particles. At this time, adjust the filter layer 210 to "adsorption layer 210b→primary filter layer 210a→fine filter layer 210c". Through the molecular sieve adsorption provided in the adsorption layer 210b, dry waste gas passes through the subsequent filter layer structure, avoiding serious dampening of the primary filter layer 210a and improving the service life of the primary filter layer 210a.

[0044] As shown in Figure 6 , the bottom of each transposition ring 310 is provided with a gas supplement assembly 320, as shown in Figure 9 , the gas supplement assembly 320 includes a gas supplement warehouse 321, a gas production warehouse 322, a gas conveying pipe 323, and a gas conveying pipe 324. The number of gas production warehouses 322 is two and is arranged on the upper and lower sides of the gas supplement warehouse 321. By setting the side of the gas production warehouse 322 away from the gas supplement warehouse 321 as a slope, the slope of the gas production warehouse 322 continuously extrudes the gas production warehouse 322 to make it deform when the transposition ring 310 moves. The air in the gas production warehouse 322 is injected into the gas supplement warehouse 321 through the gas conveying pipe 324 (specifically, the gas production warehouse 322 can be made of fatigue-resistant and high-resilience silicone rubber or TPU material to ensure that it can still maintain a stable gas production under long-term and repeated extrusion of the transposition ring 310. And the taper angle of the sealing plate 3241 and the inner wall taper of the gas conveying pipe 324 are precisely matched, and a micro fluorine rubber sealing ring is embedded on the edge to ensure that the sealing effect can achieve zero leakage under the action of the spring), and the gas conveying pipe 323 is also arranged on the gas supplement warehouse 321, as shown in Figure 5 and Figure 11As shown, the gas delivery pipe 323 includes an input pipe 3231, and the outer side of the filter plate 211 is provided with a sealing ring 212. One side of the sealing ring 212 is connected with a gas supplement pipe 216 through a spring. When the position adjustment of the filter layer 210 is completed, the spring rebounds to make the gas supplement pipe 216 butt against the input pipe 3231, so that the gas supplement pipe 216 enters the inner cavity of the input pipe 3231 and the air guide plate 3234 is pushed into the inner cavity of the air guide groove 3233. There is a gap between the air guide plate 3234 and the air guide groove 3233. After the gas supplement chamber 321 is continuously filled with gas, the air pressure increases, so that the air in the gas supplement chamber 321 is injected into the sealing ring 212 through the input pipe 3231 and the gas supplement pipe 216, the sealing ring 212 expands and precisely fits the inner wall of the purification chamber 110, so as to avoid the leakage of contaminated gas from the gap between the filter layer 210 and the inner wall of the purification chamber 110. After the position adjustment of the filter plate is completed, the sealing effect of the filter plate and the cylinder wall is enhanced, so as to avoid the leakage of waste gas which has not been treated step by step through the gap of the cylinder wall, and the damage to the subsequent filter plate.

[0045] As shown in Figure 2 , the inside of the filter replacement chamber 400 is also provided with a position adjustment gear 410, and the entrance of the filter replacement chamber 400 is provided with an electric cabin door 420. As shown in Figure 5 , the bottom of the filter plate 211 is provided with a first gear rack 214, the position adjustment gear 410 is engaged with the first gear rack 214, one end of the first gear rack 214 away from the filter replacement chamber 400 is connected with a linkage block 215, the linkage block 215 is connected with a magnet 213, and the linkage block 215 is connected to the outer side of the filter plate 211 through a spring. When the filter layer 210 is moved to the entrance of the filter replacement chamber 400, the electric cabin door 420 is opened, the electromagnet 311 is powered off, the attraction between the electromagnet 311 and the magnet 213 disappears, the spring on one side of the linkage block 215 rebounds, the linkage block 215 moves backward, one end of the first gear rack 214 enters the inner cavity of the filter replacement chamber 400 through the backward movement of the linkage block 215, and since the position adjustment gear 410 is engaged with the first gear rack 214, the rotation of the position adjustment gear 410 can make the filter layer 210 enter the inner cavity of the filter replacement chamber 400. When the position of the filter layer 210 needs to be adjusted or a single filter layer 210 needs to be replaced, the filter layer 210 enters the inner cavity of the filter replacement chamber 400, so that the position of the filter layer 210 can be adjusted, and the single filter layer can also be replaced.

[0046] As shown in Figure 3 , the gas delivery pipe 323 also includes a gas discharge pipe 3232, and the inner cavity of the gas discharge pipe 3232 is provided with a solenoid valve 3235. When the filter layer 210 needs to be moved, the solenoid valve 3235 is opened, and Figure 6As shown, the gas in the sealing ring 212 is discharged to the outside of the filter cartridge 100 through the air supplement pipe 216 and the air delivery pipe 323, the volume of the sealing ring 212 is reduced after the air is discharged, and there is a gap between the sealing ring 212 and the purification bin 110, so that the filter layer 210 can move along the inner cavity of the purification bin 110, the filter layer 210 can be moved to the movable replacement position, and the sealing between the filter layer 210 and the purification bin 110 is ensured after the position of the filter layer 210 is replaced, so as to avoid waste gas leakage.

[0047] As shown in Figure 9 and Figure 10 As shown, the inner cavity of the gas transmission pipe 324 is a tapered body, and the inner diameter gradually increases from one end to the other end. The inner cavity of the smaller end is provided with a sealing plate 3241 connected by a spring. When the gas production bin 322 is extruded and the pressure in the inner cavity increases, the sealing plate 3241 moves to the larger end under the action of the pressure, so that a gap is formed between the sealing plate 3241 and the gas transmission pipe 324. At this time, the air in the gas production bin 322 can enter the air supplement bin 321 through the gap, and after the gas in the gas production bin 322 is discharged, the pressure decreases, the spring rebounds, and the sealing plate 3241 moves to the smaller end of the inner cavity of the gas transmission pipe 324, so that the sealing plate 3241 and the gas transmission pipe 324 are in interference fit, and the gas cannot pass through, avoiding the backflow of the gas from the air supplement bin 321 to the gas production bin 322.

[0048] As shown in Figure 8 The displacement ring 310 is divided into two sections, and the two ends of the displacement ring 310 are connected by a spring. The inner side of the displacement ring 310 is provided with a plurality of electromagnets 311, as shown in Figure 7 When a certain filter layer 210 enters the inner cavity of the filter replacement bin 400, the electromagnet 311 in the corresponding displacement ring 310 loses the magnetic force connection with the magnet 213, and the spring rebounds, so that the two sections of the displacement ring 310 are dispersed and expanded and are separated from the embedded groove 331. When the filter layer 210 returns to the inner cavity of the purification bin 110, the magnet 213 and the electromagnet 311 generate an attractive force again, the two sections of the displacement ring 310 are brought together again, and are connected together with the second rack 330 through the embedded groove 331, so that the displacement ring 310 can drive the corresponding filter layer 210 to move again.

[0049] As shown in Figure 11As shown, the air guide plate 3234 is connected to the inner cavity of the input pipe 3231 by a spring, when the filter layer 210 moves to the installation position, the air supplement pipe 216 enters the inner cavity of the input pipe 3231, so that the air guide plate 3234 enters the air guide groove 3233, and since there is a gap between the air guide plate 3234 and the air guide groove 3233, the gas in the air supplement chamber 321 is injected into the sealing ring 212, and when the filter layer 210 moves, the spring rebounds, so that the air guide plate 3234 returns to the original position and tightly fits the inner wall of the input pipe 3231, thereby avoiding the leakage of the gas in the air supplement chamber 321.

[0050] As shown in the drawings, Figure 9 As shown, the air guide plate 3234 is connected to the inner cavity of the input pipe 3231 by a spring, when the filter layer 210 moves to the installation position, the air supplement pipe 216 enters the inner cavity of the input pipe 3231, so that the air guide plate 3234 enters the air guide groove 3233, and since there is a gap between the air guide plate 3234 and the air guide groove 3233, the gas in the air supplement chamber 321 is injected into the sealing ring 212, and when the filter layer 210 moves, the spring rebounds, so that the air guide plate 3234 returns to the original position and tightly fits the inner wall of the input pipe 3231, thereby avoiding the leakage of the gas in the air supplement chamber 321.

[0051] The overall device cooperates with the depth of the air supplement assembly 320 through the displacement mechanism 300, which can not only utilize the precise transmission of the displacement gear 340 and the second rack 330 to realize the precise and reliable reconstruction of the spatial positions of the multiple filter layers 210 in the purification chamber 110, so as to dynamically optimize the filtering path, but also seamlessly convert the mechanical energy of the displacement ring 310 into the power source for the inflation and deflation of the sealing ring 212 through the extrusion of the gas production chamber 322, so as to automatically form a high-pressure seal after each positioning of the filter layer and prevent waste gas from leaking.

[0052] The basic principles, main features and advantages of the present application are shown and described above. The present application is not limited by the above-mentioned embodiments, and the above-mentioned embodiments and descriptions in the specification are only illustrative of the principles of the present application. Various changes and improvements can be made to the present application without departing from the spirit and scope of the present application, and these changes and improvements all fall within the scope of the claimed present application. The scope of protection of the present application is defined by the appended claims and their equivalents.

Claims

1. A laboratory exhaust air filtration and purification device, characterized in that: The utility model relates to a filter cartridge with air injection and air exhaust control function The utility model discloses a filter cartridge (100) is internally provided with the purification bin (110), the inner wall cavity of filter cartridge (100) is provided with the movable inner groove (120) on the outside of purification bin (110) still, The filter core (200) is arranged in the inner chamber of the purification bin (110), and the filter core (200) comprises at least three filter layers (210), each filter layer (210) comprises a filter plate (211), the outer edge of the filter plate (211) is provided with a sealing ring (212), and the bottom of the filter plate (211) is provided with a first rack (214), The transposition mechanism (300) is arranged in the inner chamber of the movable inner groove (120), and the transposition mechanism (300) comprises a transposition ring (310) corresponding to the number of filter layers (210), a gas supplementing assembly (320), a second rack (330) and a displacement gear (340), the displacement gear (340) drives the second rack (330) to move vertically, drives the transposition ring (310) to drive the filter layer (210) to move vertically in the purification bin (110) synchronously, realizes filter layer sequence adjustment, the gas supplementing assembly (320) is arranged below the transposition ring (310) and is used for injecting air into the sealing ring (212) after the filter layer moves, The filter replacement bin (400) is arranged on one side of the filter cartridge (100) and is used for temporarily storing the filter layer (210) to be adjusted or replaced.

2. The waste gas filtering and purifying device for laboratory ventilation according to claim 1, characterized in that: The filter replacement bin (400) is provided with a transposition gear (410) engaged with the first rack (214), the filter layer (210) can be driven to enter or exit the filter replacement bin (400) through the engagement transmission of the transposition gear (410) and the first rack (214), and the electric hatch (420) is arranged at the inlet of the filter replacement bin (400) and is used for controlling the opening and closing of the filter replacement bin (400) to avoid uncleaned exhaust gas leakage.

3. The waste gas filtering and purifying device for laboratory ventilation according to claim 1, characterized in that: The gas supplementing assembly (320) comprises a gas supplementing bin (321), two gas generating bins (322), a gas conveying pipe (323) and a gas transmission pipe (324), the two gas generating bins (322) are arranged on the upper and lower sides of the gas supplementing bin (321) and are inclined away from the gas supplementing bin (321), the gas supplementing bin (321) receives the gas of the gas generating bin (322) or inhales external air through the gas transmission pipe (324), and then the gas supplementing bin (321) inflates the sealing ring (212) or discharges the gas in the sealing ring (212) through the gas conveying pipe (323), so that the inflation and deflation control of the sealing ring (212) is realized.

4. The waste gas filtering and purifying device for laboratory ventilation according to claim 1, characterized in that: The inner side of the transposition ring (310) is provided with a plurality of electromagnets (311), the outer side of the filter plate (211) is provided with a plurality of magnets (213), and the corresponding surfaces of the electromagnets (311) and the magnets (213) are attracted to each other.

5. The exhaust gas filtering and purifying device for laboratory ventilation according to claim 4, characterized in that: The first rack (214) is connected with a connecting block (215) at one end away from the filter changing bin (400), the connecting block (215) is connected with a magnet (213) and is connected with the filter plate (211) outside through a spring, when the attraction between the electromagnet (311) and the magnet (213) is disconnected, the spring rebounds to drive the connecting block (215) to move, so that the first rack (214) extends into the filter changing bin (400), and transmission connection is provided for the filter layer (210) to enter the filter changing bin (400).

6. The exhaust gas filtering and purifying device for laboratory ventilation according to claim 1, characterized in that: Each of the transposition rings (310) is provided with two sections and is connected through a spring, the second rack (330) is provided with an embedded groove (331) at the contact position of the transposition ring (310), when the electromagnet (311) and the magnet (213) are attracted, the two sections of the transposition ring (310) are close to each other and are connected with the transposition mechanism (300) through the embedded groove (331), when the attraction disappears, the two sections of the transposition ring (310) are separated and are separated from the embedded groove (331), so that the movement of other transposition rings (310) is avoided.

7. The waste gas filtering and purifying device for laboratory ventilation according to claim 3, characterized in that: The air transmission pipe (324) is a tapered structure, the inner diameter gradually increases from one end to the other end, and the smaller end is provided with a sealing plate (3241) connected through a spring, the air transmission pipe (324) connected with the air supplement bin (321) is connected with the air supplement bin (321) at the smaller end, and the smaller end of the air transmission pipe (324) for sucking external air penetrates the shell of the filter cartridge (100).

8. The waste gas filtering and purifying device for laboratory ventilation according to claim 3, characterized in that: The air transmission pipe (323) comprises an input pipe (3231), the inner cavity of the input pipe (3231) is provided with a gas guide groove (3233) at one end, and the inner cavity of the input pipe (3231) is provided with a gas guide plate (3234) connected through a spring at the other end.

9. The exhaust gas filtration and purification device for laboratory ventilation according to claim 8, characterized in that: The outer side of the sealing ring (212) is provided with an air supplement pipe (216) connected through a spring, the air supplement pipe (216) is in position correspondence with the input pipe (3231), when the filter layer (210) moves to the mounting position, the spring rebounds to make the air supplement pipe (216) butt joint with the input pipe (3231), and a channel is provided for the sealing ring (212) to charge and discharge air.

10. The exhaust gas filtration and purification device for laboratory ventilation according to claim 8, characterized in that: The air transmission pipe (323) further comprises an air discharge pipe (3232), the inner cavity of the air discharge pipe (3232) is provided with an electromagnetic valve (3235), when the electromagnetic valve (3235) is opened, the gas in the sealing ring (212) can be quickly discharged, the sealing ring (212) is contracted, and the movement of the filter layer (210) is facilitated.

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