Flue gas purification system for plastic processing

Abstract

The invention discloses a flue gas purification system for plastic processing, and belongs to the technical field of plastic processing. Comprising an air inlet unit, a pretreatment unit, a deep purification unit, an energy-saving recovery unit and an exhaust unit, the pretreatment unit comprises a cyclone separator and a cooling device; the deep purification unit comprises an electrostatic dust collector, an adsorption device and a catalytic oxidation device, and the electrostatic dust collector, the adsorption device and the catalytic oxidation device are sequentially arranged in the flue gas conveying direction; an adsorbent arranged in the adsorption device is composed of first modified activated carbon, second modified activated carbon and modified activated aluminum oxide; the first modified activated carbon is activated carbon of which the surface is loaded with copper; the second modified activated carbon is activated carbon loaded with graphene oxide; the modified activated aluminum oxide is obtained by sequentially modifying activated aluminum oxide with sulfuric acid and aluminum chloride. The flue gas purification system provided by the invention is high in purification efficiency, meets the environmental protection requirement, can effectively purify flue gas, and meets the industrial emission requirement.

Description

Technical Field

[0001] The invention relates to the technical field of plastic processing, and in particular to a fume purification system for plastic processing. Background Art

[0002] Plastic particles refer to granular plastics, which are generally divided into more than 200 types and subdivided into thousands of types. Common plastic particles include general-purpose plastics, engineering plastics, and special plastics. General-purpose plastics: polypropylene, polyethylene, polyvinyl chloride, polystyrene, polyester, polyurethane, etc. Engineering plastics: nylon, polytetrafluoroethylene, polyoxymethylene, polycarbonate silicone, etc. Special plastics: thermosetting plastics, functional polymer plastics, such as artificial kidneys.

[0003] During the processing of plastic particles, a large amount of smoke containing harmful substances will be generated, such as dust, volatile organic compounds (VOCs), etc. If these harmful substances are not removed, they will cause serious pollution to the environment and harm human health. Summary of the invention

[0004] The object of the present invention is to provide a fume purification system for plastic processing, which can effectively treat volatile organic compounds in the fume and effectively prevent the fume from polluting the environment and causing harm to human health.

[0005] The objective of the present invention is achieved through the following technical solutions:

[0006] A fume purification system for plastic processing, comprising an air intake unit, a pretreatment unit, a deep purification unit, an energy-saving recovery unit and an exhaust unit;

[0007] The pre-treatment unit includes a cyclone separator and a cooling device;

[0008] The deep purification unit comprises an electrostatic precipitator, an adsorption device and a catalytic oxidation device, and the electrostatic precipitator, the adsorption device and the catalytic oxidation device are arranged in sequence along the flue gas conveying direction;

[0009] The adsorbent arranged in the adsorption device consists of a first modified activated carbon, a second modified activated carbon and modified activated alumina; the first modified activated carbon is activated carbon with copper loaded on the surface; the second modified activated carbon is activated carbon loaded with graphene oxide; the modified activated alumina is obtained by modifying activated alumina with sulfuric acid and aluminum chloride in sequence.

[0010] Preferably, the adsorption device includes an adsorption box, a placement net arranged in the adsorption box, a first discharge port arranged at the bottom end of the placement net, a telescopic tube arranged at the bottom end of the first discharge port, a blocking device arranged at the first discharge port, and a telescopic device for driving the placement net to perform vertical displacement in the adsorption box; the bottom end of the telescopic tube is connected to the second discharge port arranged at the bottom end of the adsorption box; a top cover is arranged at the top end of the adsorption box, an air outlet pipe is arranged on the top cover, and an air inlet pipe is arranged on the side wall of the adsorption box and below the placement net.

[0011] Preferably, the side wall of the placement net is provided with a plurality of first sliding blocks, and the inner wall of the adsorption box is provided with a plurality of first vertical sliding grooves slidably matched with the first sliding blocks.

[0012] Preferably, the telescopic tube is composed of a plurality of mutually nested pipes, and adjacent pipes are slidably connected.

[0013] Preferably, the blocking device includes a telescopic rod arranged above the placement net, and a plurality of support rods connecting the telescopic rod to fix the telescopic rod on the placement net; when the telescopic rod is extended, the telescopic end can block the first discharge port.

[0014] Preferably, a support frame is provided at the bottom end of the adsorption box, a second hydraulic rod is provided on the support frame, a motor seat is provided at the top end of the second hydraulic rod, and a motor is provided on the motor seat;

[0015] A spiral conveying rod is arranged in the telescopic tube, a first bevel gear is sleeved on the spiral conveying rod, the first bevel gear is meshed with a second bevel gear, a rotating rod is arranged at the center of the second bevel gear, and the rotating rod is fixedly connected to the output end of the motor;

[0016] A limiting sleeve is provided on the outside of the spiral conveying rod and is located below the rotating rod. The limiting sleeve is fixedly connected to the motor seat through a connecting rod.

[0017] Preferably, a discharge pipe is provided below the second discharge port, and a side wall of the discharge pipe is provided with a through opening for the connection rod and the rotating rod to pass through.

[0018] Preferably, a movable plate is provided in the through-hole, and the movable plate can slide vertically in the through-hole, and a telescopic plate is provided between the bottom end of the movable plate and the bottom wall of the through-hole; the connecting rod passes through the movable plate and is fixedly connected to the movable plate, and the rotating rod passes through the movable plate and is rotatably connected to the movable plate.

[0019] Preferably, the mass ratio of the first modified activated carbon, the second modified activated carbon and the modified activated alumina is 10-15:10:1-2.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1. Aiming at the characteristics of flue gas in the plastic particle processing industry, the present invention provides a flue gas purification system with high purification efficiency and meeting environmental protection requirements. By allowing the flue gas to enter the air intake unit, pretreatment unit, deep purification unit, energy-saving recovery unit and exhaust unit in sequence, the flue gas can be effectively purified. Specifically, by setting a cyclone separator and a cooling device in the pretreatment unit, solid particles with larger particle sizes in the flue gas can be effectively removed, and the flue gas can be cooled at the same time to avoid the adverse effects of particles and high temperature on the adsorption effect of the adsorbent; by setting an electrostatic precipitator in the deep purification unit, dust with smaller particle sizes in the flue gas can be further removed, and by setting an adsorption device, volatile organic matter can be removed to the maximum extent. By setting a catalytic oxidation device, the remaining organic matter can be further processed.

[0022] The invention can effectively remove dust and volatile organic matter in the flue gas, so that the purified flue gas meets the industrial emission standards.

[0023] 2. By limiting the adsorbent components in the adsorption device, the removal rate of volatile organic compounds can be significantly improved. At the same time, it can effectively improve the technical defect that the activated carbon used in the prior art is prone to hardening during long-term adsorption, and effectively increase the service life of the adsorbent.

[0024] Specifically, when activated carbon alone is used as an adsorbent, the adsorption efficiency of volatile organic compounds is not high, generally less than 85%;

[0025] At the same time, after a period of flue gas adsorption, compaction problems will occur, which will seriously reduce the adsorption efficiency. The compacted activated carbon will find it difficult to further exert its adsorption effect and will be difficult to regenerate, which will seriously affect its service life.

[0026] The present invention improves the components of the adsorbent, and adjusts the components of the adsorbent to consist of a first modified activated carbon, a second modified activated carbon and a modified activated alumina. Among them, the first modified activated carbon is loaded with copper particles, which can increase the surface attraction of the activated carbon, thereby improving the adsorption effect of volatile organic compounds. After the copper particles are loaded, the hardening problem of the activated carbon can be improved, but the hardening problem is not completely improved; based on this, a second activated carbon modifier loaded with graphene oxide is added, wherein the graphene oxide is rich in hydrophilic groups, which can improve the capture of organic matter, improve the adsorption effect, and significantly improve the hardening problem of the adsorbent. In addition, the graphene oxide can also form a lubricating layer and a buffer layer on the surface of the second modified activated carbon, effectively avoiding problems such as particle crushing caused by extrusion and collision between particles; further, because the flue gas contains a certain humidity, it will have a certain impact on the adsorption effect. Based on this, the modified activated alumina is added, which can dry the flue gas and play a certain adsorption role, effectively avoiding the adverse effects of water vapor, and can further improve the hardening problem of the adsorbent.

[0027] By limiting the types of adsorbents, not only can the adsorption effect on organic matter be effectively improved, but the problem of adsorbent compaction and the problem of adsorbent breakage caused by extrusion and collision can also be effectively improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is the process flow chart in Example 1;

[0029] Figure 2 It is a schematic cross-sectional structure diagram of the filter box in the front view direction in Example 2;

[0030] Figure 3 for Figure 2 A schematic diagram of the structure of the center placement network in the top view direction;

[0031] Figure 4 for Figure 2 A schematic diagram of the structure of the middle rack as viewed from the right;

[0032] Figure 5 It is a schematic diagram of the cross-sectional structure of the telescopic tube in the top view direction;

[0033] Figure 6 It is a schematic cross-sectional structure diagram of embodiment 3 in the front view direction;

[0034] Figure 7 for Figure 6 A schematic diagram of the structure of the middle discharge pipe as viewed from the right;

[0035] Figure 8 for Figure 1 A schematic diagram of the cross-sectional structure of the middle telescopic tube in the front view direction;

[0036] In the figure: 1-adsorption box, 2-placing net, 3-first discharge port, 4-telescopic tube, 5-second discharge port, 6-inlet pipe, 7-first slider, 8-first vertical slide, 10-support rod, 9-telescopic rod, 13-horizontal plate, 14-vertical plate, 15-second hydraulic rod, 16-motor seat, 17-screw conveying rod, 18-first bevel gear, 19-rotating rod, 20-limiting sleeve, 21-connecting rod, 22-discharge pipe, 23-through-port, 24-movable plate, 25-telescopic plate. DETAILED DESCRIPTION

[0037] Example 1

[0038] A fume purification system for plastic processing, such as Figure 1 As shown, it includes an air intake unit, a pretreatment unit, a deep purification unit, an energy-saving recovery unit and an exhaust unit. The air intake unit includes an air intake pipe and a flow regulating valve. The air intake pipe is connected to the smoke exhaust port of the plastic particle processing equipment to ensure that the smoke enters the purification system smoothly. The flow regulating valve can adjust the smoke flow according to actual conditions.

[0039] The pretreatment unit includes a cyclone separator (existing technology) and a cooling device (a water cooling or air cooling device in the existing technology can be used to cool the flue gas to create favorable conditions for subsequent purification steps).

[0040] The deep purification unit comprises an electrostatic precipitator, an adsorption device and a catalytic oxidation device, and the electrostatic precipitator, the adsorption device and the catalytic oxidation device are arranged in sequence along the flue gas conveying direction.

[0041] The energy-saving recovery unit includes a waste heat recovery device and a heat exchanger.

[0042] The exhaust system consists of an exhaust pipe and a detection device.

[0043] The adsorbent arranged in the adsorption device consists of a first modified activated carbon, a second modified activated carbon and modified activated alumina; the first modified activated carbon is activated carbon with copper loaded on the surface; the second modified activated carbon is activated carbon loaded with graphene oxide; the modified activated alumina is obtained by modifying activated alumina with sulfuric acid and aluminum chloride in sequence; the mass ratio of the first modified activated carbon, the second modified activated carbon and the modified activated alumina is 10:10:1.

[0044] Among them, the preparation method of the first modified activated carbon is: add 40mL of 0.5mol·L-1 CuCl2 solution to 5g of 50-100 mesh activated carbon, stir thoroughly, wash with water until neutral, dry at 100-105°C for 24h, and then calcine at 500°C for 2h under N2 atmosphere.

[0045] The preparation method of the second modified activated carbon refers to the preparation method in Example 1 in patent CN202111195614.6.

[0046] The preparation method of modified activated alumina is as follows: add a 50 mmol / L H2SO4 solution to 50-100 mesh activated alumina at a solid-liquid mass ratio of 1:5, soak for 0.5 h, then wash with deionized water until neutral, and put into a 110°C oven for drying; then add a 0.5% A1Cl3 solution at a solid-liquid mass ratio of 1:15, soak for 1 h, then wash with deionized water until neutral, and dry.

[0047] Here’s how it works:

[0048] The flue gas in the production of plastic particles is introduced into the pretreatment unit along the air intake duct of the air intake unit, and then the larger dust particles (solid particles ≥10μm) in the flue gas are separated by the cyclone separator in the pretreatment unit, and the flue gas is cooled by a cooling device (air cooling or water cooling device) to reduce the temperature of the flue gas to below 50 degrees Celsius;

[0049] The electrostatic precipitator in the deep purification unit removes the tiny dust particles (dust of 0.01-50μm) in the flue gas. The concentration of volatile organic matter in the flue gas after dust removal is 167mg / m 3 , relative humidity <38%, then the volatile organic matter in the flue gas is adsorbed by the adsorbent in the adsorption device, and the concentration of volatile organic matter after adsorption is 11.7mg / m 3 , the removal rate is 93%; finally, the remaining harmful substances in the flue gas are oxidized and decomposed into harmless substances to the greatest extent through a catalytic oxidation device (any catalytic oxidizer in the prior art can be selected).

[0050] The waste heat in the flue gas is collected by the waste heat recovery device in the energy-saving recovery unit, and the heat is transferred to the cooling device of the pretreatment unit or other links requiring thermal energy through the heat exchanger, so as to realize energy recycling and reduce energy consumption;

[0051] The purified flue gas is discharged into the atmosphere through the exhaust duct of the exhaust unit, and the detection device monitors the quality of the exhaust gas in real time to ensure that the emission meets the standards.

[0052] Example 2

[0053] In the prior art, the adsorption device usually includes an adsorption box 1 and a placement net 2 fixedly arranged in the adsorption box 1. Since the activated carbon is usually added into the adsorption box 1 from the top, and the adsorption box 1 has a certain height, the activated carbon is easily broken when it collides with the placement net 2 or the activated carbon added to the placement net 2 during the addition, which has an adverse effect on the adsorption of flue gas.

[0054] Based on this, on the basis of Example 1, the present invention defines the structure of the adsorption device, such as Figure 2 As shown, it includes an adsorption box 1, a placement net 2 arranged in the adsorption box 1, a first discharge port 3 arranged at the bottom end of the placement net 2, a telescopic tube 4 arranged at the bottom end of the first discharge port 3, a blocking device arranged at the first discharge port 3, and a telescopic device for driving the placement net 2 to perform vertical displacement in the adsorption box 1. In this embodiment, a first hydraulic rod is selected; the bottom end of the telescopic tube 4 is connected to a second discharge port 5 arranged at the bottom end of the adsorption box 1; a top cover is arranged on the top end of the adsorption box 1, an air outlet pipe is arranged on the top cover, and an air inlet pipe 6 is arranged on the side wall of the adsorption box 1 and below the placement net 2. Further, as Figure 1 and Figure 2 As shown, the side wall of the placement net 2 is provided with a plurality of first sliding blocks 7 , and the inner wall of the adsorption box 1 is provided with a plurality of first vertical sliding grooves 8 slidably matched with the first sliding blocks 7 .

[0055] Further, such as Figure 5 and Figure 8 As shown, the telescopic tube 4 is composed of a plurality of mutually nested pipes (the specific number of pipes depends on the actual situation), and there is a very slight gap between adjacent pipes. Figure 8 As shown, between two adjacent pipes, a second slider is provided on the inner pipe outer wall, and a second vertical slide groove slidably matched with the second slider is provided on the outer pipe inner wall. Since the top and bottom ends of the second vertical slide groove are not connected to the outside, the second slider can be effectively prevented from sliding out of the second vertical slide groove.

[0056] Further, such as Figure 2 As shown, the blocking device includes a telescopic rod 9 arranged above the placement net 2, and a plurality of support rods 10 connecting the telescopic rod 9 to the placement net 2; when the telescopic rod 9 is extended, the telescopic end of the telescopic rod 9 can block the first discharge port 3. Figure 2 As shown, the telescopic rod 9 is composed of an outer rod and an inner rod, and the top wall of the outer rod is conical to avoid material accumulation when collecting the adsorbent. The outer wall of the inner rod is provided with a third slider (the third slider and the third vertical slide groove are both prior art and are not shown in the figure), and the inner wall of the outer rod is provided with a third vertical slide groove (the top and bottom ends are not connected to the outside world) that is slidably matched with the third slider. Therefore, the inner rod can slide up and down inside the outer rod. In addition, when the telescopic rod 9 is stationary, under the action of the gravity of the inner rod, the third slider can slide down autonomously in the third vertical slide groove, so that the bottom end of the inner rod blocks the first discharge port 3 (as shown in FIG. Figure 2 shown).

[0057] Further, such as Figure 1and Figure 4 As shown, a support frame is provided at the bottom end of the adsorption box 1, and a second hydraulic rod 15 is provided on the support frame. A motor seat 16 is provided at the top of the second hydraulic rod 15, and a motor is provided on the motor seat 16; a spiral conveying rod 17 is provided in the telescopic tube 4, and a first bevel gear 18 is sleeved on the spiral conveying rod 17. The first bevel gear 18 and the second bevel gear are meshed. A rotating rod 19 is provided at the center of the second bevel gear, and the rotating rod 19 is fixedly connected to the output end of the motor; in order to limit the spiral conveying rod 17, as shown in FIG. Figure 2 As shown, a stop sleeve 20 is provided outside the spiral conveying rod 17 and below the rotating rod 19 (a bearing is provided between the spiral conveying rod 17 and the stop sleeve 20, which is not shown in the figure), and the stop sleeve 20 is fixedly connected to the motor seat 16 through a connecting rod 21. Figure 4 As shown, the support frame includes a horizontal plate 13 and two vertical plates 14 arranged at the top of the horizontal plate 13, the vertical plate 14 is connected to the bottom end of the adsorption box 1, the second hydraulic rod 15 is installed at the top of the horizontal plate 13, and the motor seat 16 is slidably connected to the two vertical plates 14, that is, in actual implementation, the motor seat 16 can slide vertically in the two vertical plates 14 by setting a slide rail or the like.

[0058] Working principle: When adding adsorbent, open the top cover, then start the first hydraulic rod to move the placement net 2 upward. During the upward movement, the first slider 7 slides up in the first vertical slide 8. At the same time, the inner rod in the telescopic rod 9 automatically slides down to the first discharge port 3 under the action of medium gravity to block the first discharge port 3. In addition, multiple pipes in the telescopic tube 4 slide with each other to gradually extend the telescopic tube 4 to adapt to the height of the placement net 2. When the placement net 2 slides up to the top of the adsorption box 1, add adsorbent to the adsorption box 1. At this time, the placement net 2 is closer to the top of the adsorption box 1. Therefore, there will be no large gravitational potential energy when the adsorbent is added, so there will be no collision with the placement net 2 to damage the adsorbent. When the adsorbent is continuously added, the first hydraulic rod is retracted to make the placement net 2 move down continuously to ensure that the position where the adsorbent falls and the position where the material is added are close. After the placement net 2 completely slides down to the bottom end of the first vertical slide groove 8, the top cover is put on, and the top cover can be fixed by bolts or the like.

[0059] When the adsorbent needs to be replaced, the second hydraulic rod 15 is started to synchronously move the motor seat 16, the connecting rod 21, the limit sleeve 20 and the screw conveying rod 17 and other components arranged on the motor seat 16 upward. During the upward movement, the screw conveying rod 17 pushes the inner rod upward, so that the inner rod slides up inside the outer rod until it slides to the maximum limit. At this time, there is a certain distance between the telescopic rod 9 and the first discharge port 3, which can make the adsorbent slide to the first discharge port 3 autonomously. After that, the motor is started, and under the action of the motor, the rotating rod 19 is rotated, thereby driving the first bevel gear 18, the second bevel gear and the screw conveying rod 17 to rotate. When the screw conveying rod 17 rotates, its top end is rotatably connected with the bottom end of the inner rod, and the screw conveying rod 17 can promote the discharge of the adsorbent to avoid blockage in the telescopic tube 4. After the adsorbent is discharged through the first discharge port 3, the telescopic tube 4 and the second discharge port 5, it can be collected.

[0060] After the adsorbent is completely discharged, the second hydraulic rod 15 is closed, so that the motor seat 16 drives the components thereon to return to their original positions.

[0061] It is worth mentioning that if the adsorbent is activated carbon, this device is not applicable. Generally speaking, the premise for replacing the adsorbent is that its adsorption performance is reduced and it is difficult to complete the adsorption operation. At this time, the activated carbon may become compacted to a certain extent. When compacted, the material is not unloaded smoothly. The compacted activated carbon on the placement net 2 may not slide smoothly to the first discharge port 3, and the spiral conveying rod 17 only has a conveying function at the first discharge port 3, and the activated carbon that has not fallen to the first discharge port 3 is difficult to convey.

[0062] Example 3

[0063] Since the discharge pipe 22 is not provided at the second discharge port 5 in Example 2, it is extremely inconvenient to collect the adsorbent. Due to the provision of devices such as a support frame, it is inconvenient to place the collection container directly at the second discharge port 5, which causes the adsorbent to leak easily.

[0064] Based on this, on the basis of Example 2, as Figure 6 and Figure 7 As shown, a discharge pipe 22 is provided below the second discharge port 5, and a through hole 23 is provided on the side wall of the discharge pipe 22 for the connection rod 21 and the rotating rod 19 to pass through. Figure 6 and Figure 7 As shown, a movable plate 24 is disposed in the through hole 23, and the movable plate 24 can slide vertically in the through hole 23 without falling off, and a telescopic plate 25 is disposed between the bottom end of the movable plate 24 and the bottom wall of the through hole 23, as shown in FIG. Figure 7As shown, the telescopic plate 25 includes an upper plate and a lower plate, the upper plate and the lower plate are slidably connected, the upper plate is connected to the movable plate, and the lower plate is connected to the bottom wall of the through-hole 23; the connecting rod 21 penetrates the movable plate 24 and is fixedly connected to the movable plate 24, and the rotating rod 19 penetrates the movable plate 24 and is rotatably connected to the movable plate 24.

[0065] Working principle: When collecting adsorbent, first place the collection container at the bottom of the discharge pipe 22, then start the second hydraulic rod 15, so that the motor seat 16 drives the moving plate 24 to slide up in the through-hole 23 until the moving plate 24 slides to the top wall of the through-hole 23. At this time, the spiral conveying rod 17 just pushes the inner rod to the highest position. During the upward movement of the moving plate 24, the upper plate and the inner plate of the telescopic plate 25 slide relative to each other to adapt to the height of the moving plate 24 to prevent the adsorbent from spilling along the through-hole 23. Afterwards, start the motor to smoothly collect.

[0066] Comparative Example 1

[0067] Compared with Example 1, only the adsorbent was changed to activated carbon, and the other steps and conditions remained unchanged.

[0068] The adsorption device has a removal rate of 81% for volatile organic compounds.

[0069] The agglomeration of the adsorbent in Example 1 and Comparative Example 1 was recorded, and the two were operated simultaneously under the same external conditions. When the activated carbon in Comparative Example 1 was obviously agglomerated, the adsorbent in Example 1 was not agglomerated.

Claims

1. A fume purification system for plastic processing, characterized in that: It includes air intake unit, pretreatment unit, deep purification unit, energy-saving recovery unit and exhaust unit; The pre-treatment unit includes a cyclone separator and a cooling device; The deep purification unit comprises an electrostatic precipitator, an adsorption device and a catalytic oxidation device, and the electrostatic precipitator, the adsorption device and the catalytic oxidation device are arranged in sequence along the flue gas conveying direction; The adsorbent arranged in the adsorption device consists of a first modified activated carbon, a second modified activated carbon and modified activated alumina; the first modified activated carbon is activated carbon with copper loaded on the surface; the second modified activated carbon is activated carbon with graphene oxide loaded on the surface; the modified activated alumina is obtained by modifying activated alumina in sequence with sulfuric acid and aluminum chloride.

2. A fume purification system for plastic processing according to claim 1, characterized in that: The adsorption device comprises an adsorption box (1), a placement net (2) arranged in the adsorption box (1), a first discharge port (3) arranged at the bottom end of the placement net (2), a telescopic tube (4) arranged at the bottom end of the first discharge port (3), a blocking device arranged at the first discharge port (3), and a telescopic device for driving the placement net (2) to perform vertical displacement in the adsorption box (1); the bottom end of the telescopic tube (4) is connected to a second discharge port (5) arranged at the bottom end of the adsorption box (1); a top cover is arranged at the top end of the adsorption box (1), an air outlet pipe is arranged on the top cover, and an air inlet pipe (6) is arranged on the side wall of the adsorption box (1) and below the placement net (2).

3. A fume purification system for plastic processing according to claim 2, characterized in that: The side wall of the placement net (2) is provided with a plurality of first sliding blocks (7), and the inner wall of the adsorption box (1) is provided with a plurality of first vertical sliding grooves (8) that are slidably matched with the first sliding blocks (7).

4. A fume purification system for plastic processing according to claim 2, characterized in that: The telescopic tube (4) is composed of a plurality of mutually nested pipes, and adjacent pipes are slidably connected.

5. A fume purification system for plastic processing according to claim 2, characterized in that: The blocking device comprises a telescopic rod (9) arranged above the placement net (2), and a plurality of supporting rods (10) connecting the telescopic rod to fix the telescopic rod on the placement net (2); when the telescopic rod (9) is extended, the telescopic end can block the first discharge port (3).

6. A fume purification system for plastic processing according to claim 5, characterized in that: A support frame is provided at the bottom end of the adsorption box (1), a second hydraulic rod (15) is provided on the support frame, a motor seat (16) is provided at the top end of the second hydraulic rod (15), and a motor is provided on the motor seat (16); A spiral conveying rod (17) is arranged in the telescopic tube (4), a first bevel gear (18) is sleeved on the spiral conveying rod (17), the first bevel gear (18) is meshed with a second bevel gear, a rotating rod (19) is arranged at the center of the second bevel gear, and the rotating rod (19) is fixedly connected to the output end of the motor; A limiting sleeve (20) is provided outside the spiral conveying rod (17) and is located below the rotating rod (19). The limiting sleeve (20) is fixedly connected to the motor seat (16) via a connecting rod (21).

7. A fume purification system for plastic processing according to claim 6, characterized in that: A discharge pipe (22) is provided below the second discharge port (5), and a through hole (23) is provided on the side wall of the discharge pipe (22) for the connection rod (21) and the rotating rod (19) to pass through.

8. A fume purification system for plastic processing according to claim 7, characterized in that: A movable plate (24) is arranged in the through-opening (23), and the movable plate (24) can slide vertically in the through-opening (23), and a telescopic plate (25) is arranged between the bottom end of the movable plate (24) and the bottom wall of the through-opening (23); the connecting rod (21) passes through the movable plate (24) and is fixedly connected to the movable plate (24), and the rotating rod (19) passes through the movable plate (24) and is rotationally connected to the movable plate (24).

9. A fume purification system for plastic processing according to claim 1, characterized in that: The mass ratio of the first modified activated carbon, the second modified activated carbon and the modified activated alumina is 10-15:10:1-2.

Images