A kind of waste gas adsorption device for seed coating agent production

Abstract

The utility model relates to a kind of waste gas adsorption device for seed coating production, including fixed frame, lower spray tank being fixedly installed in the lower end of the inner side of fixed frame and upper adsorption tank being fixedly installed in the upper portion of the inner side of fixed frame, the bottom of lower spray tank outer wall is equipped with air inlet pipe, air inlet pipe is used to guide the waste gas generated in seed coating production process into lower spray tank inside, exhaust pipe is used to discharge the purification gas after adsorption treatment, the upper end of lower spray tank and the lower end of upper adsorption tank are communicated by communication valve;The utility model is adsorbed to the waste gas of pretreatment by adsorption, and it is handled to adsorption bed by combining steam regeneration, the adsorption effect of waste gas is guaranteed, while according to the feedback of pH sensor, in spray treatment, the acid-base of waste gas is neutralized, avoid acidic or alkaline material damage adsorption bed, and after regeneration process, nitrogen is purged, oxygen is replaced while cooling, prevent the oxidation of adsorption bed, the service life of adsorption bed is guaranteed.

Description

Technical Field

[0001] This utility model relates to the field of seed coating agent production technology, specifically to a waste gas adsorption device for seed coating agent production. Background Technology

[0002] In modern agricultural production, seed coating agents are widely used in seed treatment to achieve multiple effects such as disease prevention, pest control, growth promotion, and improved germination rate. Seed coating agents are usually prepared by mixing, emulsifying, and reacting components such as film-forming agents, active ingredients, dispersants, solvents, and auxiliaries. However, during their production, especially in the stages of ingredient preparation, stirring, reaction, and drying, a large amount of mixed waste gas containing volatile organic compounds (VOCs), ammonia (NH3), hydrogen sulfide (H2S), acidic gases (such as HCl and SO2), and fine dust is released. This type of waste gas is characterized by complex composition, strong odor, high toxicity of some components, and flammability and explosiveness. If it is discharged directly into the atmosphere without effective treatment, it will not only cause serious environmental pollution but also pose a threat to human health and safety hazards. Therefore, in the production of seed coating agents, it is necessary to treat the waste gas through adsorption devices.

[0003] Currently, the waste gas from seed coating agent production is generally treated by adsorption filtration, which involves the use of adsorption devices. However, the overall treatment capacity is limited, affected by the performance of the filter element, and the filter element is prone to clogging during the adsorption process, directly affecting the filtration efficiency. Based on this, we propose a waste gas adsorption device for seed coating agent production to solve the above problems. Utility Model Content

[0004] To address the shortcomings of existing technologies, this utility model provides an adsorption device for waste gas from seed coating agent production. It employs a spray structure to pre-treat the waste gas, reducing particulate matter in the waste gas, before adsorption filtration, ensuring adsorption efficiency. This solves the problem that existing methods for treating waste gas from seed coating agent production generally use adsorption filtration, which involves adsorption devices but has limited overall processing capacity, is affected by the performance of the filter element, and is prone to clogging during the adsorption process.

[0005] To achieve the above objectives, this utility model provides the following technical solution: a waste gas adsorption device for seed coating agent production, comprising a fixed frame, a lower spray box fixedly installed at the lower end of the inner side of the fixed frame, and an upper adsorption box fixedly installed at the upper part of the inner side of the fixed frame. An air inlet pipe is provided at the bottom of the outer wall of the lower spray box, which is used to guide the waste gas generated during the seed coating agent production process into the lower spray box. An exhaust pipe is provided at the top of the upper adsorption box, which is used to discharge the purified gas after adsorption treatment. The upper end of the lower spray box and the lower end of the upper adsorption box are connected by a connecting valve to realize the switching control between working state and maintenance / regeneration state. Three spray units are arranged vertically on the upper part of the inner side of the lower spray box. The lower spray box has three water inlet pipes on its outer wall. Each water inlet pipe is connected to an external water supply device and is used to supply washing liquid with different pH values. It is equipped with a solenoid valve for automatic switching. The bottom inner side of the lower spray box is equipped with a detection component for real-time detection of the pH value of the circulating washing liquid. The upper adsorption box has two layers of adsorption beds distributed from top to bottom. The upper adsorption box is also equipped with two sets of purging components. The purging components are used to introduce nitrogen into the adsorption bed for inert gas purging after desorption and regeneration. The upper and lower ends of the outer wall of the upper adsorption box are equipped with desorption pipes. The two desorption pipes are used to input high-temperature steam into the upper adsorption box to realize the regeneration of the adsorbent and to discharge saturated steam carrying pollutants.

[0006] Furthermore, the bottom of the lower spray box is equipped with a dirt sedimentation area, the air outlet of the air inlet pipe is located above the dirt sedimentation area, and a drain pipe is provided at the lower end of the lower spray box. The drain pipe is connected to the dirt sedimentation area and is equipped with a control valve.

[0007] Furthermore, the spray unit includes a water distribution pipe fixedly installed on the inner wall of the lower spray box and multiple atomizing nozzles evenly arranged on the upper surface of the water distribution pipe. The water distribution pipe is arranged at equal intervals along the horizontal direction inside the lower spray box.

[0008] It should be noted that the waste gas from seed coating agents often contains fine dust and sticky additive particles. If it enters the adsorption bed directly, it can easily cause pore blockage. This device achieves efficient dust removal and cooling through three-stage atomization spraying, providing a clean gas source for subsequent adsorption.

[0009] Furthermore, the three water inlet pipes are respectively connected to an external neutral water supply system, an acidic detergent storage device, and an alkaline detergent supply system, and each water inlet pipe is equipped with a solenoid valve.

[0010] Furthermore, the detection component includes a bracket fixedly installed at the bottom of the lower spray box and a pH sensor installed on the bracket. The bracket is set in the dirt sedimentation area but above the sedimentation surface, so that the pH sensor is immersed in the flowing washing liquid. It is used to continuously monitor the acid-base changes of the liquid after absorbing the exhaust gas. The pH sensor signal is connected to the central controller to determine whether the exhaust gas contains acidic or alkaline gases and trigger the corresponding washing liquid switching action.

[0011] It is important to note that changes in pH value reflect the dissolution of soluble gases such as NH3 and HCl in the exhaust gas. Combined with the linkage between the central controller and the solenoid valve, it truly realizes intelligent response of exhaust gas property identification and washing strategy adjustment. The pH sensor serves as the feedback sensing unit for the entire waste gas pretreatment system. Together with the central controller (such as a PLC or embedded control system), solenoid valve assembly, and dosing system, it forms an intelligent closed-loop control circuit. Based on the dynamic changes in acidic and alkaline pollutants in the waste gas, it automatically switches to the optimal type of scrubbing liquid (tap water or recycled water, neutral water with pH≈7, acidic solution with dilute sulfuric acid (H2SO4, 1%) or citric acid solution (pH=3~4), or alkaline solution with a concentration of 0.5%~2%). This ensures efficient absorption, prevents adsorbent poisoning, and extends the system's operating cycle. 1. If pH < 6.0, the exhaust gas contains strong acidic components (such as HCl, organic acid vapor), open the solenoid valve on the alkaline washing liquid inlet pipe and inject NaOH solution (concentration 0.5~2%) to neutralize the acidic substances, while closing the other two valves; 2. If pH > 9.0, the exhaust gas contains a lot of alkaline gases (such as NH3 and amines). Open the solenoid valve on the acidic washing liquid inlet pipe and inject dilute sulfuric acid or citric acid solution (pH ≈ 3~4) to absorb ammonia. Then close the other two circuits. 3. If pH 6.0 ≤ pH ≤ 9.0, indicating light gaseous pollution or predominantly neutral VOCs, keep all solenoid valves closed and continue circulating spraying with only neutral water; if stable for a long period, indicate "No need to add chemicals"; Simultaneously, if the continuous rate of pH increase is >0.3pH / min, a sudden release of ammonia gas (such as when the reactor is opened) triggers an early warning and initiates the addition of acidic liquid in advance to prevent penetration. Conversely, if the continuous rate of pH decrease is >0.3pH / min, a sudden increase in acidic gas occurs, prompting the initiation of the addition of alkaline liquid in advance to enhance the response speed.

[0012] Furthermore, the adsorption bed is filled with hydrophobic modified zeolite molecular sieves and high-iodine-value coconut shell activated carbon. The hydrophobic modified zeolite molecular sieves are used to preferentially adsorb polar small molecule gases such as ammonia and hydrogen sulfide, while the high-iodine-value coconut shell activated carbon is used to efficiently capture volatile organic compounds such as benzene series compounds, alcohols, and ketones, thus forming a gradient composite adsorption structure.

[0013] It should be noted that modified zeolite has strong moisture resistance and is suitable for capturing amines and ammonia commonly used in seed coating processes, while activated carbon mainly targets organic solvent vapors. The two have a clear division of labor and complement each other, overcoming the shortcomings of poor selectivity of single adsorbents.

[0014] Furthermore, the purging assembly includes an outer frame fixedly installed on the inner wall of the upper adsorption chamber, an air blowing pipe embedded inside the outer frame, and multiple air outlets evenly opened along the axial direction of the air blowing pipe. Both ends of the air blowing pipe are connected to the internal cavity of the outer frame. An air supply pipe is provided on the outer wall of the upper adsorption chamber. One end of the air supply pipe is connected to the outer frame, and the other end of the air supply pipe is connected to an external nitrogen source. When nitrogen is input, the adsorption bed is cooled and purged.

[0015] It should be noted that the adsorption bed temperature is high after steam desorption, and the residual VOCs vapor may form an explosive mixture when it comes into contact with air. Introducing nitrogen can effectively cool the bed and replace the oxygen, preventing oxidation and fire, and improving the inherent safety of the equipment.

[0016] Furthermore, the two desorption pipes are connected to the top and bottom of the upper adsorption box respectively, forming a steam penetration path from top to bottom or from bottom to top. The desorption pipes are connected to an external steam generator and a condensation recovery system through a pipeline switching valve. When steam is sent into the upper adsorption box, the high-temperature steam passes through the two adsorption beds.

[0017] Compared with the prior art, the technical solution of this application has the following beneficial effects: 1. This waste gas adsorption device for the production of this type of coating agent removes dust particles, water-soluble gases and aerosols from the waste gas through multi-stage spray pretreatment, and then performs adsorption filtration. Combined with steam regeneration treatment of the adsorption bed, the adsorption treatment effect and efficiency are guaranteed. 2. This type of waste gas adsorption device for clothing production, based on the switching of washing liquid according to the feedback of pH sensor, can automatically select neutral, acidic or alkaline washing liquid for targeted absorption according to the changes in acid and alkaline components in the waste gas, thereby neutralizing the acidity or alkalinity of the waste gas and avoiding damage to the adsorption bed by acidic or alkaline substances. 3. In the waste gas adsorption device for this type of coating agent production, during steam regeneration, steam penetrates the adsorption bed, easily forming heat accumulation in the adsorption bed. By using nitrogen purging, oxygen is replaced while cooling down, preventing oxidation of the adsorption bed and ensuring its service life. Attached Figure Description

[0018] Figure 1 The diagram shown is a schematic representation of the overall structure of this utility model. Figure 1 ; Figure 2 The diagram shown is a schematic representation of the overall structure of this utility model. Figure 2 ; Figure 3 The diagram shown is a schematic representation of the internal structure of this utility model. Figure 4 The diagram shown is a schematic representation of the spray unit structure of this utility model. Figure 5 The diagram shown is a schematic representation of the outer frame structure of this utility model. Figure 6 The diagram shown is a schematic of the upper adsorption box structure of this utility model.

[0019] Explanation of reference numerals in the attached drawings: 1. Fixing frame; 2. Lower spray box; 21. Water distribution pipe; 22. Atomizing nozzle; 201. Bracket; 202. pH sensor; 3. Upper adsorption box; 301. Outer frame; 302. Air blowing pipe; 303. Air supply pipe; 4. Air inlet pipe; 5. Exhaust pipe; 6. Connecting valve; 7. Water inlet pipe; 8. Adsorption bed; 9. Desorption pipe. Detailed Implementation

[0020] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0021] Please see Figures 1-6 This embodiment of a waste gas adsorption device for seed coating agent production includes a fixed frame 1, a lower spray box 2 fixedly installed on the lower inner side of the fixed frame 1, and an upper adsorption box 3 fixedly installed on the upper inner side of the fixed frame 1. An air inlet pipe 4 is provided at the bottom of the outer wall of the lower spray box 2, which is used to guide the waste gas generated during the seed coating agent production process into the lower spray box 2. An exhaust pipe 5 is provided at the top of the upper adsorption box 3, which is used to discharge the purified gas after adsorption treatment. The upper end of the lower spray box 2 and the lower end of the upper adsorption box 3 are connected by a connecting valve 6 (preferably model QD71X-16DN100). Three spray units are arranged vertically on the upper inner side of the lower spray box 2, and three corresponding spray units are provided on the outer wall of the lower spray box 2. Water inlet pipe 7, each connected to an external water supply device and used to supply washing liquid with different pH values. The bottom inner side of the lower spray box 2 is equipped with a detection component, which is used to detect the pH value of the circulating washing liquid in real time. The upper adsorption box 3 is equipped with two layers of adsorption beds 8 distributed from top to bottom. The interior of the adsorption bed 8 is filled with hydrophobic modified zeolite molecular sieve and high iodine value coconut shell activated carbon. The upper adsorption box 3 is also equipped with two sets of purging components, which are used to purge the adsorption bed 8 with nitrogen gas after desorption and regeneration. The upper and lower ends of the outer wall of the upper adsorption box 3 are equipped with desorption pipes 9. The two desorption pipes 9 are used to input high temperature steam into the upper adsorption box 3 to realize the regeneration of the adsorbent and to discharge saturated steam carrying pollutants.

[0022] It should be noted that the waste gas from the seed coating agent production is sent into the lower spray box 2 through the air inlet pipe 4. After being treated by the spray unit, the dust and other substances in the waste gas are adsorbed. Then the waste gas flows upward and enters the upper adsorption box 3, so that the waste gas passes through the spray zone and the adsorption zone from bottom to top in sequence to achieve the adsorption treatment of the waste gas. When entering the desorption stage, the connecting valve 6 is closed to cut off the connection with the external airflow and ensure the steam seal circulation.

[0023] In this embodiment, the bottom of the lower spray box 2 is provided with a dirt sedimentation area, the air outlet of the air inlet pipe 4 is located above the dirt sedimentation area, and the lower end of the lower spray box 2 is provided with a drain pipe, which is connected to the dirt sedimentation area and is equipped with a control valve.

[0024] It should be noted that the air inlet pipe 4 is located above the dirt sedimentation area, thereby reducing the impact of air intake on the sedimentation area and facilitating wastewater sedimentation. The bottom drain pipe discharges the sedimented impurities and wastewater, preventing excessive water volume at the bottom.

[0025] Please see Figure 1 , Figure 3 and Figure 4 In this embodiment, the spray unit includes a water distribution pipe 21 fixedly installed on the inner wall of the lower spray box 2 and a plurality of atomizing nozzles 22 evenly arranged on the upper surface of the water distribution pipe 21. The water distribution pipe 21 is arranged at equal intervals in the horizontal direction inside the lower spray box 2. The three water inlet pipes 7 are respectively connected to the external neutral water supply system, the acidic detergent storage device and the alkaline detergent supply system, and each water inlet pipe 7 is equipped with a solenoid valve.

[0026] It should be noted that the atomizing nozzle 22 is a solid cone-shaped pressure nozzle with a working pressure of 0.2~0.4MPa and a droplet size of ≤80μm. It can efficiently capture dust particles and soluble gases. The solenoid valves on the three water inlet pipes 7 are corrosion-resistant direct-acting solenoid valves (model SY-A-1 / 2 "PVC acid and alkali resistant"). They are controlled by a DC24V signal output from the PLC. The corresponding water inlet pipe 7 is opened according to the spraying needs, thereby changing the acidity or alkalinity of the spray.

[0027] Please see Figure 1 and Figure 3 In this embodiment, the detection component includes a bracket 201 fixedly installed at the bottom of the lower spray box 2 and a pH sensor 202 installed on the bracket 201. The bracket 201 is located in the dirt sedimentation area but above the sedimentation surface, so that the pH sensor 202 is immersed in the flowing washing liquid. It is used to continuously monitor the acid-base changes of the liquid after absorbing the waste gas. The pH sensor 202 signal is connected to the central controller to determine whether the waste gas contains acidic or alkaline gas and trigger the corresponding washing liquid switching action.

[0028] It should be noted that the pH sensor 202 is an industrial online pH meter, model YSIProDSS series, with automatic temperature compensation (equipped with Pt100 RTD), a measurement range of 0.14 pH, and an accuracy of ±0.1 pH. The sensor is installed in the pre-drilled hole of bracket 201 via a threaded interface for easy disassembly and cleaning. The PLC module (such as Siemens S7-1200CPU1214C) has a built-in PID control algorithm, which receives pH data in real time and executes preset logic. When pH < 6.0 for more than 1 minute, the alkaline liquid solenoid valve is automatically opened. When pH > 9.0, the acidic liquid addition is started. After restoring to the 6.0-9.0 range, the valve is delayed and shut off to prevent frequent start-stop. At the same time, the controller can upload data to the plant's DCS system via RS485 interface to achieve remote monitoring.

[0029] Please see Figure 2 , Figure 3 , Figure 5 In this embodiment, the purging assembly includes an outer frame 301 fixedly installed on the inner wall of the upper adsorption box 3, an air blowing pipe 302 embedded inside the outer frame 301, and a plurality of air outlets evenly opened along the axial direction of the air blowing pipe 302. The two ends of the air blowing pipe 302 are connected to the internal cavity of the outer frame 301. The outer wall of the upper adsorption box 3 is provided with an air supply pipe 303. One end of the air supply pipe 303 is connected to the outer frame 301, and the other end of the air supply pipe 303 is connected to an external nitrogen source. When nitrogen is input, the adsorption bed 8 is cooled and purged.

[0030] It should be noted that the outer frame 301 is a ring-shaped stainless steel support, welded to the inner wall of the upper adsorption chamber 3, forming a closed gas chamber inside; the blowing pipe 302 is a perforated distribution pipe with an opening diameter of φ35mm and a spacing of 100mm, arranged in a spiral to ensure uniform distribution of nitrogen gas throughout the entire cross-section of the adsorption bed 8; the gas delivery pipe 303 connects to industrial bottled nitrogen or an on-site nitrogen generator (flow rate ≥2m³ / h). 3 / h, purity ≥99.5%), the pressure is adjusted to 0.1-0.2MPa through the pressure reducing valve. The nitrogen purging program is set to start after the vapor desorption is completed, and the duration is 20-30 minutes. It has three main functions: ① Removes residual steam and reduces humidity; ② Cool the high-temperature adsorbent (from 100℃ to below 40℃); ③ Replace oxygen to prevent activated carbon from oxidizing and catching fire when it comes into contact with air at high temperatures.

[0031] Another implementation of the purging assembly in this embodiment: To adapt to different specifications of adsorption chambers and higher requirements for uniform gas distribution, the purging assembly includes a tube embedded inside the adsorption bed 8. The tube has multiple air outlets circumferentially opened, and one end of the tube is a closed end. The other end of the tube extends to the outside of the upper adsorption chamber 3 and connects to the gas supply pipe 303. By supplying nitrogen gas, it penetrates from the inside of the adsorption bed 8 to the outside, which can quickly reduce the internal temperature of the adsorption bed 8. The array distribution of the tubes makes the distribution of nitrogen gas more uniform.

[0032] In this embodiment, two desorption pipes 9 are respectively connected to the top and bottom of the upper adsorption box 3 to form a steam penetration path from top to bottom or from bottom to top. The desorption pipes 9 are connected to an external steam generator and a condensation recovery system through a pipeline switching valve. When steam is sent into the upper adsorption box 3, the high-temperature steam passes through the two adsorption beds 8.

[0033] It should be noted that the desorption tube 9 is made of high-temperature resistant stainless steel. The top inlet is used to introduce steam downwards (suitable for heavily polluted upper layers), and the bottom inlet is used for upward countercurrent penetration (to improve penetration uniformity). The steam source is an electrically heated steam generator (rated pressure 0.4MPa, temperature 120℃). The steam inlet direction is selected by a two-position three-way valve. The desorption process is set at a temperature of 100~120℃ and a duration of 60~90 minutes. The desorbed pollutants enter the subsequent condensation system (tube condenser, cooling water temperature ≤25℃) with the steam to achieve organic solvent recovery (such as ethanol, acetone, etc.). Non-condensable gases are returned to the adsorption tank or connected to the secondary treatment unit. The entire desorption cycle can be set to once every 7 days according to the production rhythm.

[0034] The working principle of the above embodiments is as follows: Normal adsorption operation phase: The exhaust gas enters the lower spray box 2 through the inlet pipe 4. During the upward process, it comes into full contact with the three-stage atomized spray liquid to remove dust, cool down and absorb soluble gases such as NH3 and HCl. The purified gas enters the upper adsorption box 3 through the connecting valve 6, and passes through the hydrophobic modified zeolite layer (adsorbing polar gases) and the high iodine value activated carbon layer (adsorbing organic VOCs) in sequence, and finally meets the emission standards.

[0035] Intelligent control stage: The pH sensor 202 continuously monitors the state of the washing solution. Once a sudden change in acidity or alkalinity is detected, the PLC immediately instructs the corresponding solenoid valve to open, accurately adding acidic or alkaline washing solution to maintain the optimal absorption environment.

[0036] Desorption and regeneration stage: Periodically close the connecting valve 6 to start the steam desorption program. High-temperature steam penetrates the adsorption bed 8, causing the adsorbate to desorb and be discharged to the condensation system with the steam. After desorption is completed, the nitrogen purging program is automatically switched to complete the cooling and inerting protection.

[0037] Wastewater drainage and fluid replenishment assistance: The system regularly drains the accumulated dirt at the bottom and replenishes fresh washing liquid based on feedback from the liquid level sensor to maintain long-term stable operation.

[0038] It should be noted that the control method of this utility model is controlled by a controller. The control circuit of the controller can be implemented by those skilled in the art through simple programming. The power supply is also common knowledge in the field. Furthermore, this utility model is mainly used to protect mechanical devices, so the control method and circuit connection will not be explained in detail here.

[0039] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0040] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A waste gas adsorption device for seed coating agent production, characterized in that: The system includes a fixed frame (1), a lower spray box (2) fixedly installed on the lower inner side of the fixed frame (1), and an upper adsorption box (3) fixedly installed on the upper inner side of the fixed frame (1). The bottom of the outer wall of the lower spray box (2) is provided with an air inlet pipe (4), which is used to introduce the waste gas generated during the seed coating agent production process into the lower spray box (2). The top of the upper adsorption box (3) is provided with an exhaust pipe (5), which is used to discharge the purified gas after adsorption treatment. The upper end of the lower spray box (2) is connected to the lower end of the upper adsorption box (3) through a connecting valve (6). Three spray units are arranged vertically on the upper inner side of the lower spray box (2), and three corresponding spray units are arranged on the outer wall of the lower spray box (2). Water inlet pipe (7), each water inlet pipe (7) is connected to an external water supply device and used to supply washing liquid with different pH values. The bottom of the inner side of the lower spray box (2) is equipped with a detection component, which is used to detect the pH value of the circulating washing liquid in real time. The upper adsorption box (3) is equipped with two layers of adsorption beds (8) distributed from top to bottom. The upper adsorption box (3) is also equipped with two sets of purging components. The purging components are used to introduce nitrogen into the adsorption bed (8) after desorption and regeneration for inert gas purging. The upper and lower ends of the outer wall of the upper adsorption box (3) are equipped with desorption pipes (9). The two desorption pipes (9) are used to input high temperature steam into the upper adsorption box (3) to realize the regeneration of the adsorbent and to discharge saturated steam carrying pollutants.

2. The waste gas adsorption device for seed coating agent production according to claim 1, characterized in that: The bottom of the lower spray box (2) is provided with a dirt sedimentation area. The air outlet of the air inlet pipe (4) is located above the dirt sedimentation area. The lower end of the lower spray box (2) is provided with a drain pipe, which is connected to the dirt sedimentation area and is equipped with a control valve.

3. The waste gas adsorption device for seed coating agent production according to claim 1, characterized in that: The spray unit includes a water distribution pipe (21) fixedly installed on the inner wall of the lower spray box (2) and multiple atomizing nozzles (22) evenly arranged on the upper surface of the water distribution pipe (21). The water distribution pipe (21) is arranged at equal intervals in the horizontal direction inside the lower spray box (2).

4. The waste gas adsorption device for seed coating agent production according to claim 3, characterized in that: The three water inlet pipes (7) are respectively connected to the external neutral water supply system, the acidic detergent storage device and the alkaline detergent supply system, and each water inlet pipe (7) is equipped with a solenoid valve.

5. The waste gas adsorption device for seed coating agent production according to claim 2, characterized in that: The detection component includes a bracket (201) fixedly installed at the bottom of the lower spray box (2) and a pH sensor (202) installed on the bracket (201). The bracket (201) is set in the dirt sedimentation area but above the sedimentation surface, so that the pH sensor (202) is immersed in the flowing washing liquid. It is used to continuously monitor the acid-base change of the liquid after absorbing the waste gas. The pH sensor (202) signal is connected to the central controller to determine whether the waste gas contains acidic or alkaline gas and trigger the corresponding washing liquid switching action.

6. The waste gas adsorption device for seed coating agent production according to claim 1, characterized in that: The adsorption bed (8) is filled with hydrophobic modified zeolite molecular sieves and high iodine value coconut shell activated carbon.

7. The waste gas adsorption device for seed coating agent production according to claim 1, characterized in that: The purging assembly includes an outer frame (301) fixedly installed on the inner wall of the upper adsorption box (3), an air blowing pipe (302) embedded in the outer frame (301), and multiple air outlets evenly opened along the axial direction of the air blowing pipe (302). The two ends of the air blowing pipe (302) are connected to the cavity inside the outer frame (301). The outer wall of the upper adsorption box (3) is provided with an air supply pipe (303). One end of the air supply pipe (303) is connected to the outer frame (301), and the other end of the air supply pipe (303) is connected to an external nitrogen source. When nitrogen is input, the adsorption bed (8) is cooled and purged.

8. The waste gas adsorption device for seed coating agent production according to claim 1, characterized in that: Two desorption pipes (9) are connected to the top and bottom of the upper adsorption box (3) respectively, forming a steam penetration path from top to bottom or from bottom to top. The desorption pipes (9) are connected to the external steam generator and condensation recovery system through the pipeline switching valve. When the steam is sent into the upper adsorption box (3), the high temperature steam passes through the two adsorption beds (8).

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