A waste gas treatment system for paint spraying

Abstract

The present application provides a kind of waste gas treatment system for paint spraying, including waste gas absorption pump, high pressure air pump and multiple series waste gas absorption tank, waste gas enters system through waste gas suction pipe, high pressure nozzle is equipped in each waste gas absorption tank, is connected atomizing spray head, spray chemical treatment liquid and waste gas fully mixed reaction.Each waste gas absorption tank is internally mounted with rotating cover and obliquely arranged rotating blade, improve airflow direction and contact efficiency.First chemical agent storage tank adds material to first mixing cylinder by spiral conveying rod, prepares chemical treatment liquid;Waste gas is sent into demisting tank after treatment, removes residual mist using demisting core, finally is discharged through exhaust pipe.Second chemical agent storage tank collects wastewater and preliminarily processes, then wastewater is pumped into sedimentation filter, particulate filter and dissolved salt filter for depth purification by water pump.The present application has efficient, compact design, and can carry out depth treatment to absorbed wastewater.

Description

Technical Field

[0001] This invention belongs to the field of environmental engineering technology and relates to a waste gas treatment system for spray painting. Background Technology

[0002] In the industrial manufacturing sector, spray painting is widely used in industries such as automobiles, furniture, machinery, and electronics to improve product appearance and corrosion resistance. However, the spray painting process generates a large amount of harmful waste gas containing volatile organic compounds (VOCs), paint mist particles, and acidic or alkaline gases (such as benzene compounds, esters, ketones, toluene, xylene, etc.). Direct emission without effective treatment will not only cause serious air pollution but may also endanger the health of operators and violate increasingly stringent environmental regulations. Therefore, efficient and reliable purification of the waste gas generated during the spray painting process has become a critical technical problem that related industries urgently need to solve.

[0003] Currently, the main methods for treating paint spraying exhaust gas include adsorption, combustion, biodegradation, and wet absorption. Among these, wet absorption is a common treatment method due to its simple equipment structure, low operating cost, and suitability for exhaust gases with high humidity and particulate matter content. Especially when treating paint spraying exhaust gas containing acidic components or water-soluble organic pollutants, spray towers are often used as the core treatment device. Spray towers spray alkaline solutions or other suitable absorbents into the tower, causing harmful components in the exhaust gas to undergo physical dissolution or chemical reactions during gas-liquid contact, thereby transforming them into relatively harmless or easily treated substances, achieving preliminary purification of the exhaust gas.

[0004] However, most existing spray towers employ a static spray absorption mode, where waste gas relies on natural flow within the tower to contact the liquid droplets sprayed from top to bottom. This method suffers from problems such as short gas-liquid contact time, limited contact area, and low mass transfer efficiency, resulting in a slow absorption rate of harmful gases and purification efficiency that fails to meet increasingly stringent emission standards. Furthermore, the wastewater treated by spraying often contains high concentrations of organic matter, heavy metal ions, and reaction byproducts, exhibiting high chemical oxygen demand and toxicity. Direct discharge would cause secondary pollution, necessitating the construction of a wastewater treatment system for advanced treatment, increasing overall operating costs and management complexity. Summary of the Invention

[0005] The purpose of this invention is to provide a paint spraying exhaust gas treatment system with a high efficiency and compact design, and to perform deep treatment on the absorbed wastewater to ensure that the final discharge meets or exceeds current environmental quality standards.

[0006] To solve the above-mentioned technical problems, the present invention provides a waste gas treatment system for spray painting, including a waste gas absorption pump and a high-pressure air pump. The inlet end of the waste gas absorption pump is connected to a waste gas suction pipe, and the system also includes multiple waste gas absorption tanks. All waste gas absorption tanks are connected in series through air guide pipes. A high-pressure spray pipe is provided in the middle of each waste gas absorption tank, and multiple atomizing nozzles distributed along its height are connected to the outside of each high-pressure spray pipe. A high-pressure air pipe is provided outside each high-pressure spray pipe, and each atomizing nozzle is connected to a corresponding high-pressure air pipe. Except for the high-pressure nozzle inside the exhaust gas absorption tank at the head end, all other high-pressure nozzles are connected to the outlet end of the high-pressure air pump through the air inlet pipe. The high-pressure nozzle inside the exhaust gas absorption tank at the head end is connected to the outlet end of the exhaust gas absorption pump through the exhaust gas inlet pipe. Each exhaust gas absorption tank is rotatably connected with a rotating cover that is fitted with a corresponding high-pressure nozzle and a corresponding high-pressure air pipe. Each rotating cover has multiple vertically distributed through holes on its outer periphery. One side of each vertical through hole is inclined outward with a rotating blade. All rotating blades on each rotating cover are inclined in the same direction.

[0007] It also includes a first chemical agent storage tank, the lower end of which is connected to a first mixing cylinder. A first spiral conveying rod for adding materials into the first mixing cylinder is rotatably connected inside the first chemical agent storage tank. A first drive motor for driving the first spiral conveying rod to rotate is installed at the upper end of the first chemical agent storage tank. A tap water connection pipe is connected to the upper part of the first mixing cylinder. One end of each high-pressure spray pipe is connected to the lower part of the first mixing cylinder through a liquid inlet pipe.

[0008] It also includes a demister canister, the lower part of which is connected to the exhaust gas absorption canister at the tail end through a mist pipe. A demister core is provided in the upper middle part of the demister canister. The demister core has multiple spiral demister channels that spiral upward from bottom to top. An exhaust pipe is connected to the upper end of the demister canister.

[0009] It also includes a second chemical agent storage tank, the lower end of which is connected to a second mixing cylinder. A second spiral conveyor rod for adding materials into the second mixing cylinder is rotatably connected inside the second chemical agent storage tank. A second drive motor for driving the second spiral conveyor rod to rotate is installed at the upper end of the second chemical agent storage tank. The lower part of each waste gas absorption tank is connected to the upper part of the second chemical agent storage tank through a wastewater pipe. The lower part of the demister is connected to the upper part of the second chemical agent storage tank through a drain pipe.

[0010] It also includes a water pump, the inlet of which is connected to the lower part of the second chemical agent storage tank through a negative pressure pipe, the outlet of which is connected to a sedimentation filter through a water outlet pipe, the outlet of which is connected to a particulate filter through a first water guide pipe, the particulate filter through a second water guide pipe, and the outlet of which is connected to a clean water pipe.

[0011] By adopting the above technical solution, when exhaust gas is generated, a negative pressure is generated by the exhaust gas absorption pump to suck away the exhaust gas generated during painting, and the exhaust gas is connected to the high-pressure gas pipe through the exhaust gas inlet pipe. During the process, tap water flows into the first mixing cylinder. The first drive motor drives the first spiral conveyor to rotate and add the chemical reagent in the first chemical agent storage tank to the first mixing cylinder (the selection of chemical reagent is based on the type of exhaust gas generated). The chemical reagent and water are quickly mixed and dissolved into a solution in the first mixing cylinder, enter the high-pressure spray pipe, and are mixed with the exhaust gas at the atomizing nozzle and sprayed out to form water mist that fully contacts the exhaust gas, so that the water mist fully absorbs the harmful gases in the exhaust gas, and the mist is deposited at the bottom of the exhaust gas absorption tank.

[0012] The exhaust gas then enters the next exhaust gas absorption tank through the air guide pipe. In the next exhaust gas absorption tank, the solution mixes with the air and is sprayed out from the atomizing nozzle to form water mist, which absorbs the residual harmful gases in the exhaust gas. The absorbed water mist is also deposited at the bottom of the exhaust gas absorption tank. Finally, the exhaust gas after absorption enters the demister tank. In the demister tank, the atomized water droplets gradually come into contact with and are adsorbed on the inner wall as they pass from bottom to top through a dense spiral demister channel. Then, they flow down the spiral demister channel to the bottom of the demister tank. Finally, the exhaust gas that has completed absorption and demistering is discharged from the exhaust pipe.

[0013] The pump operates, creating negative pressure in the system. This negative pressure causes the solution at the bottom of the waste gas absorption tank to flow into the second mixing cylinder. The second drive motor then rotates the second screw conveyor to add chemical reagents from the second chemical storage tank into the second mixing cylinder (the selection of chemical reagents depends on the type of waste gas generated and the chemical reagents used in the first chemical storage tank). The chemical reagents dissolve fully in the solution in the second mixing cylinder, undergoing an acid-base neutralization reaction to adjust the pH of the wastewater. Precipitation may occur during this process. Finally, the wastewater enters a sedimentation filter to remove large particles, a particulate filter to remove remaining small precipitates, and a dissolved salt filter to remove unreacted compounds. The wastewater is then discharged from the clear water pipe.

[0014] The present invention is further configured such that the waste gas absorption pump and the high-pressure air pump share a single power motor, and the power motor is a dual-head motor, with both ends of the power output shaft of the power motor extending into the waste gas absorption pump and the high-pressure air pump respectively to drive the impellers inside them to rotate.

[0015] The present invention is further configured such that the lower part of the first chemical agent storage tank and the second chemical agent storage tank are provided with a conical inner bottom, and the lower end of each conical inner bottom is provided with a feeding pipe downward. The upper end of the first mixing cylinder and the second mixing cylinder are both open. The first spiral conveying rod and the second spiral conveying rod each include a spiral guide rod in the corresponding conical inner bottom and a spiral feeding rod in the corresponding feeding pipe. The outer diameter of each spiral guide rod is larger than the outer diameter of the corresponding spiral feeding rod.

[0016] The present invention is further configured such that a connecting shaft is provided inside both the first mixing cylinder and the second mixing cylinder, and a plurality of spiral guide blades are provided on the outer periphery of each connecting shaft, and a gap is left between each spiral guide blade and the inner wall of the first mixing cylinder or the inner wall of the second mixing cylinder.

[0017] The present invention is further configured such that both the first chemical agent storage tank and the second chemical agent storage tank are provided with a feeding port at the top.

[0018] The present invention is further configured such that each atomizing nozzle has a connecting pipe at the end away from its nozzle, and each connecting pipe is provided with a liquid inlet chamber connected to the corresponding high-pressure nozzle and an air inlet chamber connected to the corresponding high-pressure air pipe.

[0019] The present invention is further configured such that the sedimentation filter is provided with a replaceable coarse filter element, the particulate filter is provided with a replaceable ultrafiltration filter element, and the dissolved salt filter is provided with a replaceable reverse osmosis filter element.

[0020] The present invention is further configured such that an electromagnetic valve is provided on the drain pipe, and a liquid level sensor for monitoring the liquid level in the lower part of the demister is provided in the lower part of the demister.

[0021] The present invention is further configured such that the second mixing cylinder is connected to a pH alkali sensor for monitoring the pH value of the solution inside it.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] I. This invention introduces an innovative atomized waste gas absorption mechanism. The sprayed fine water mist drives a rotating hood to rotate continuously. This rotation effectively agitates the waste gas and water mist, achieving deep fusion and reaction between them. This significantly improves the speed and efficiency of the absorption solution in capturing pollutants from the waste gas. Therefore, the waste gas absorption tank does not need to be excessively large, nor does it require complex and lengthy multi-stage absorption processes to fully purify the waste gas. This results in a more compact overall structure and significantly improved operational efficiency while achieving highly efficient absorption.

[0024] Second, the waste gas absorption system of the present invention has the function of real-time automatic preparation of absorption solution, eliminating the need for pre-preparation and storage of large quantities of treatment solution. During operation, the absorption liquid is dynamically generated and replenished with the water flow. Only a sufficient amount of chemical reagent needs to be added initially to support the long-term stable operation of the system, which reduces the number of operation steps and storage requirements, and also improves the flexibility and convenience of system use.

[0025] Third, after the exhaust gas absorption is completed, the resulting wastewater first enters an automatically prepared acid-base neutralization treatment stage to effectively neutralize any remaining acidic or alkaline components and remove harmful substances. Subsequently, the wastewater passes through a multi-stage series filtration system to gradually remove suspended sediments, fine particles, and dissolved salts, ultimately ensuring that the effluent quality not only meets but also exceeds the current environmental quality standards, thereby achieving safe and clean discharge. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0027] Figure 2 Used to demonstrate the back structure of the present invention;

[0028] Figure 3 This is a partial sectional view used to show the internal structure of the waste gas absorption tank;

[0029] Figure 4 It is a partial cross-sectional view used to show the high-pressure nozzle, high-pressure air pipe and atomizing nozzle inside the exhaust gas absorption tank;

[0030] Figure 5 It is a partial cross-sectional view used to show the internal structure of a connecting pipe;

[0031] Figure 6 This is a partial sectional view used to show the internal structure of the demister canister;

[0032] Figure 7 This is a partial cross-sectional view used to show the internal structure of the first chemical storage tank and the first mixing cylinder;

[0033] Figure 8 This is a partial cross-sectional view used to show the internal structure of the second chemical storage tank and the second mixing cylinder;

[0034] Figure 9 It is a partial cross-sectional view used to show the internal structure of sedimentation filters, particulate filters and dissolved salt filters.

[0035] The components include: 1. Waste gas absorption pump; 2. High-pressure air pump; 3. Power motor; 4. Waste gas intake pipe; 5. Waste gas absorption tank; 6. Air guide pipe; 7. High-pressure nozzle; 8. Atomizing nozzle; 9. High-pressure air pipe; 10. Connecting pipe; 11. Liquid inlet chamber; 12. Air inlet chamber; 13. Waste gas inlet pipe; 14. Air inlet pipe; 15. Rotating hood; 16. Vertical through hole; 17. Rotating blade; 18. First chemical agent storage tank; 19. First mixing cylinder; 20. First screw conveyor rod; 21. First drive motor; 22. Tap water connection pipe; 23. Liquid inlet pipe; 24. Demisting tank; 25. Mist pipe; 26. Demisting core; 27. Spiral demisting channel; 28. Exhaust... 29. Gas pipe; 30. Second chemical storage tank; 31. Second mixing cylinder; 32. Second screw conveyor; 33. Second drive motor; 34. pH alkali sensor; 35. Wastewater pipe; 36. Drain pipe; 37. Solenoid valve; 38. Liquid level sensor; 49. Feed port; 40. Conical inner bottom; 41. Feed pipe; 42. Connecting shaft; 43. Spiral guide vane; 44. Water pump; 45. Negative pressure pipe; 46. Water outlet pipe; 47. Sedimentation filter; 48. First water guide pipe; 49. Particulate filter; 50. Second water guide pipe; 51. Dissolved salt filter; 52. Coarse filter element; 53. Ultrafiltration filter element; 54. Reverse osmosis filter element; 55. Clean water pipe. Detailed Implementation

[0036] The following detailed description, in conjunction with the accompanying drawings and specific embodiments, provides a further detailed explanation of the exhaust gas treatment system for spray painting proposed in this invention. The advantages and features of this invention will become clearer from the following description. It should be noted that the drawings are all in a very simplified form and use non-precise proportions, and are only used to facilitate and clarify the illustration of the embodiments of this invention. The same or similar reference numerals in the drawings represent the same or similar parts.

[0037] Example, refer to Figure 1-9 A paint spraying exhaust gas treatment system includes an exhaust gas absorption pump 1 and a high-pressure air pump 2. The exhaust gas absorption pump 1 and the high-pressure air pump 2 share a power motor 3, and the power motor 3 is a dual-head motor. The two ends of the power output shaft of the power motor 3 extend into the exhaust gas absorption pump 1 and the high-pressure air pump 2 respectively to drive the impeller inside to rotate. The inlet end of the exhaust gas absorption pump 1 is connected to an exhaust gas suction pipe 4, and the free end of the exhaust gas suction pipe 4 is connected to the paint spraying area, which can be directly connected to a cover for absorbing the gas at the paint spraying area.

[0038] It also includes two exhaust gas absorption tanks 5. Multiple exhaust gas absorption tanks 5 can be designed according to usage requirements. All exhaust gas absorption tanks 5 are connected in series through a gas guide pipe 6. One end of the gas guide pipe 6 is connected to the upper part of the previous exhaust gas absorption tank 5, and the other end of the gas guide pipe 6 is connected to the lower part of the next exhaust gas absorption tank 5. A high-pressure nozzle 7 is provided in the middle of each exhaust gas absorption tank 5 along its length. Multiple atomizing nozzles 8 are connected to the outside of each high-pressure nozzle 7 along its height, and the atomizing nozzles 8 are asymmetrically distributed. A high-pressure air pipe 9 is provided outside each high-pressure nozzle 7, and the high-pressure air pipe 9 is spirally wound around the outside of the high-pressure nozzle 7. Each atomizing nozzle 8 has a connecting pipe 10 at the end furthest from its nozzle. Each connecting pipe 10 contains a liquid inlet chamber 11 connected to the corresponding high-pressure nozzle 7 and an air inlet chamber 12 connected to the corresponding high-pressure air pipe 9. This allows high-pressure water and high-pressure air to enter the atomizing nozzle 8 simultaneously, where the shear force generated upon encountering the water breaks up the liquid flow, forming fine droplets. The high-pressure nozzle 7 in the exhaust gas absorption tank 5 at the head end is connected to the outlet of the exhaust gas absorption pump 1 via an exhaust gas inlet pipe 13, allowing the exhaust gas to contact the water droplets more evenly and further aiding in the absorption of harmful gases in the exhaust gas. The remaining high-pressure nozzles 7 are all connected to the outlet of the high-pressure air pump 2 via an air inlet pipe 14. Each waste gas absorption tank 5 is rotatably connected to a rotating cover 15, which corresponds to the high-pressure nozzle 7 and the high-pressure air pipe 9. Each rotating cover 15 has multiple circumferentially distributed vertical through holes 16 on its outer periphery. Each vertical through hole 16 has a rotating blade 17 tilted outward on one side. All rotating blades 17 on each rotating cover 15 are tilted in the same direction. When the sprayed high-pressure water mist hits the rotating blade 17, it can drive the rotating cover 15 to rotate, causing the rotating blade 17 to rotate and agitate the internal airflow, so that the waste gas and water mist are fully mixed.

[0039] It also includes a first chemical agent storage tank 18, the lower end of which is connected to a first mixing cylinder 19. A first screw conveyor 20 is rotatably connected inside the first chemical agent storage tank 18 to add materials into the first mixing cylinder 19. Chemical reagents are added into the first mixing cylinder 19 through the first screw conveyor 20. A first drive motor 21 for driving the first screw conveyor 20 to rotate is installed at the upper end of the first chemical agent storage tank 18. A tap water connection pipe 22 is connected to the upper part of the first mixing cylinder 19. After the tap water connection pipe 22 is connected to tap water, a high-pressure water flow is generated. One end of each high-pressure spray pipe 7 is connected to the lower part of the first mixing cylinder 19 through a liquid inlet pipe 23, so that the mixed chemical reagents in the first mixing cylinder 19 are introduced into the waste gas absorption tank 5 for spray absorption.

[0040] It also includes a demister 24. The lower part of the demister 24 is connected to the exhaust gas absorption tank 5 at the tail end through a mist pipe 25. A demister core 26 is set in the upper middle part of the demister 24. There are gaps between the upper and lower ends of the demister core 26 and the upper and lower ends of the demister 24. The demister core 26 has multiple spiral demister channels 27 that spiral upward from bottom to top. When the atomized water droplets pass through the spiral demister channels 27, the water droplets gradually come into contact with and are adsorbed on the inner wall of the spiral demister channels 27, and then flow down along the spiral demister channels 27 to the bottom of the demister 24. The upper end of the demister 24 is connected to an exhaust pipe 28. Finally, the air discharged from the exhaust pipe 28 is free of water mist.

[0041] It also includes a second chemical agent storage tank 29, the lower end of which is connected to a vertically arranged second mixing cylinder 30. A second spiral conveyor 31 for adding materials into the second mixing cylinder 30 is rotatably connected inside the second chemical agent storage tank 29. A second drive motor 32 for driving the second spiral conveyor 31 to rotate is installed at the upper end of the second chemical agent storage tank 29. A pH sensor 33 for monitoring the pH value of the solution inside the second mixing cylinder 30 is connected to the second mixing cylinder 30. The pH value inside the second mixing cylinder 30 is monitored in real time by the pH sensor 33, and the rotation of the second spiral conveyor 31 is controlled according to the pH value to add neutralizing agent into the second mixing cylinder 30. Each waste gas absorption tank 5 is connected to the upper part of the second chemical agent storage tank 29 via a wastewater pipe 34 at its lower part. The demister 24 is connected to the upper part of the second chemical agent storage tank 29 via a drain pipe 35 at its lower part. A solenoid valve 36 is installed on the drain pipe 35. A liquid level sensor 37 is installed in the lower part of the demister 24 to monitor the liquid level at its lower part. The liquid level sensor 37 monitors the liquid level at the bottom of the demister 24. When the liquid in the demister 24 reaches a certain capacity, the solenoid valve 36 is opened to discharge the internal liquid.

[0042] Both the first chemical reagent storage tank 18 and the second chemical reagent storage tank 29 are provided with a feeding port 38 at the top to facilitate the addition of corresponding chemical reagents. The lower part of the first chemical reagent storage tank 18 and the second chemical reagent storage tank 29 is provided with a conical inner bottom 39. A feeding pipe 40 is provided downward at the lower end of each conical inner bottom 39. The first mixing cylinder 19 and the second mixing cylinder 30 are both open at the top. The first spiral conveying rod 20 and the second spiral conveying rod 31 each include a spiral guide rod in the corresponding conical inner bottom 39 and a spiral feeding rod in the corresponding feeding pipe 40. The outer diameter of each spiral guide rod is larger than the outer diameter of the corresponding spiral feeding rod. The rotation of the spiral guide rod causes the internal reagents to gather at the bottom, and the rotation of the spiral feeding rod slowly adds chemical reagents into the first mixing cylinder 19 or the second mixing cylinder 30. Both the first mixing cylinder 19 and the second mixing cylinder 30 are equipped with a connecting shaft 41. Each connecting shaft 41 has multiple spiral guide blades 42 on its outer periphery. Each spiral guide blade 42 has a gap between itself and the inner wall of the first mixing cylinder 19 or the inner wall of the second mixing cylinder 30, allowing water and chemical reagents to enter the mixing cylinder. Under the action of the spiral guide blades 42, a spiral vortex is formed, which fully mixes the two and accelerates dissolution.

[0043] It also includes a water pump 43. The inlet of the water pump 43 is connected to the lower part of the second chemical storage tank 29 through a negative pressure pipe 44. The outlet of the water pump 43 is connected to a sedimentation filter 46 through a water outlet pipe 45. The outlet of the sedimentation filter 46 is connected to a particulate filter 48 through a first water guide pipe 47. The particulate filter 48 is connected to a dissolved salt filter 50 through a second water guide pipe 49. The sedimentation filter 46 is equipped with a replaceable coarse filter element 51 to filter out most of the precipitate generated by the reaction. The particulate filter 48 is equipped with a replaceable ultrafiltration filter element 52 to filter out small precipitates. The dissolved salt filter 50 is equipped with a replaceable reverse osmosis filter element 53 to filter out most of the unreacted compounds in the water. The outlet of the dissolved salt filter 50 is connected to a clear water pipe 54.

[0044] Working principle: When exhaust gas is generated, the exhaust gas absorption pump 1 creates negative pressure to actively draw away the exhaust gas generated during the painting process. The exhaust gas is introduced into the high-pressure gas pipe 9 through the exhaust gas inlet pipe 13. At the same time, tap water continuously flows into the first mixing cylinder 19. The first drive motor 21 starts, driving the first spiral conveyor rod 20 to rotate, thereby accurately and quantitatively adding specific chemical reagents stored in the first chemical agent storage tank 18 into the first mixing cylinder 19 (the specific selection of chemical reagents depends on the type and composition characteristics of the exhaust gas being treated). The chemical reagents and water are stirred at high speed and quickly mixed and dissolved in the first mixing cylinder 19 to form a uniform chemical solution. The solution is then conveyed to the high-pressure nozzle 7 and sprayed out in the form of high-pressure atomization at the atomizing nozzle 8. It meets and mixes thoroughly with the exhaust gas introduced from the high-pressure air pipe 9. The sprayed fine water mist has a large area and high efficiency contact with the exhaust gas flow. The chemical substances in the water mist can fully capture and absorb the various harmful gas components contained in the exhaust gas. After absorption, the mist gradually settles at the bottom of the exhaust gas absorption tank 5 due to gravity.

[0045] Subsequently, the pre-treated exhaust gas is guided through the air guide pipe 6 to the next exhaust gas absorption tank 5. In this subsequent absorption tank, the pre-prepared solution is mixed with air and then sprayed out again as a fine water mist through the atomizing nozzle 8. This second water mist barrier aims to further absorb any remaining harmful gases in the exhaust gas, ensuring more thorough purification. The absorbed water mist will also settle and collect at the bottom of the exhaust gas absorption tank 5. After multi-stage absorption treatment, the exhaust gas is then introduced into the demister 24 for demisting. Inside the demister 24, the exhaust gas passes from bottom to top through the densely arranged spiral demisting channels 27. As it passes through these winding channels, the atomized water droplets carried in the exhaust gas gradually collide with and are adsorbed onto the inner wall of the channel. The condensed water droplets then flow down the wall of the spiral demisting channel 27 and finally collect at the bottom of the demister 24. Thus, the purified exhaust gas, having completed the absorption of harmful gases and removal of moisture, is discharged from the top exhaust pipe 28 in compliance with standards.

[0046] In the post-treatment stage of the system operation, the water pump 43 starts working, creating a negative pressure environment in the system. Driven by this negative pressure, the absorbed solution accumulated at the bottom of each waste gas absorption tank 5 is uniformly drawn into the second mixing cylinder 30. During this process, the integrated pH sensor 33 monitors the acidity and alkalinity of the solution flowing into the second mixing cylinder 30 in real time and continuously. The second drive motor 32 then starts, driving the second spiral conveyor rod 31 to rotate. Based on the monitored pH value, another chemical reagent stored in the second chemical reagent storage tank 29 (the selection of which needs to take into account the characteristics of the original waste gas and the types of reagents already used in the first chemical reagent storage tank 18) is precisely added to the second mixing cylinder 30. The added chemical reagent is fully mixed with the solution in the second mixing cylinder 30 and undergoes a chemical reaction, usually acid-base neutralization, to adjust the pH value of the wastewater to a safe or dischargeable range. Insoluble precipitates may be generated during this reaction. Finally, the chemically treated wastewater is fed into a sedimentation filter 46, where large particles are first filtered and separated. Next, the wastewater passes through a particulate filter 48 to further remove any remaining fine particles. Finally, the wastewater passes through a dissolved salt filter 50 to remove unreacted or reactive soluble compounds, ensuring deep purification. The purified water is then discharged from the system via a clean water pipe 54, where it can be recycled or discharged in compliance with standards.

[0047] It should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0048] The above description is merely a description of preferred embodiments of the present invention and is not intended to limit the scope of the present invention in any way. Any changes or modifications made by those skilled in the art based on the above disclosure shall fall within the protection scope of the claims.

Claims

1. A waste gas treatment system for spray painting, comprising a waste gas absorption pump (1) and a high-pressure air pump (2), wherein the inlet end of the waste gas absorption pump is connected to a waste gas suction pipe (4), characterized in that: It also includes multiple waste gas absorption tanks (5), all of which are connected in series via a gas guide pipe (6); It also includes a first chemical agent storage tank (18), the lower end of which is connected to a first mixing cylinder (19), the upper part of which is connected to a tap water connection pipe (22), and one end of each high-pressure nozzle (7) is connected to the lower part of the first mixing cylinder through a liquid inlet pipe (23). It also includes a demister (24), the lower part of which is connected to the exhaust gas absorption tank at the tail end through a mist pipe (25). A demister core (26) is provided in the upper middle part of the demister. The demister core has multiple spiral demister channels (27) that spiral upward from bottom to top. An exhaust pipe (28) is connected to the upper end of the demister. It also includes a second chemical agent storage tank (29), the lower end of which is connected to a second mixing cylinder (30), the lower part of each waste gas absorption tank is connected to the upper part of the second chemical agent storage tank through a wastewater pipe (34), and the lower part of the demister is connected to the upper part of the second chemical agent storage tank through a drain pipe (35). It also includes a water pump (43), the inlet end of which is connected to the lower part of the second chemical agent storage tank through a negative pressure pipe (44), the outlet end of which is connected to a sedimentation filter (46) through a water outlet pipe (45), the outlet end of which is connected to a particulate filter (48) through a first water guide pipe (47), the particulate filter through a second water guide pipe (49) through a dissolved salt filter (50), and the outlet end of which is connected to a clean water pipe (54).

2. The exhaust gas treatment system for spray painting according to claim 1, characterized in that: Each waste gas absorption tank is provided with a high-pressure nozzle arranged along its length in the middle. Each high-pressure nozzle is connected to a plurality of atomizing nozzles (8) distributed along its height on the outside. Each high-pressure nozzle is provided with a high-pressure air pipe (9). Each atomizing nozzle is connected to the corresponding high-pressure air pipe. Except for the high-pressure nozzle in the waste gas absorption tank at the head end, the other high-pressure nozzles are connected to the outlet end of the high-pressure air pump through the air inlet pipe (14). The high-pressure nozzle in the waste gas absorption tank at the head end is connected to the outlet end of the waste gas absorption pump through the waste gas inlet pipe (13). Each waste gas absorption tank is rotatably connected with a rotating cover (15) that covers the corresponding high-pressure nozzle and the corresponding high-pressure air pipe. Each rotating cover has a plurality of vertical through holes (16) arranged in a circle on its outer periphery. Each vertical through hole has a rotating blade (17) tilted outward on one side. All rotating blades on each rotating cover are tilted in the same direction.

3. The exhaust gas treatment system for spray painting according to claim 1, characterized in that: The waste gas absorption pump and the high-pressure air pump share a power motor (3), and the power motor is a dual-head motor. The two ends of the power output shaft of the power motor extend into the waste gas absorption pump and the high-pressure air pump respectively to drive the impeller inside them to rotate.

4. The exhaust gas treatment system for spray painting according to claim 1, characterized in that: The first chemical agent storage tank is rotatably connected to a first spiral conveyor rod (20) for adding materials into the first mixing cylinder. The upper end of the first chemical agent storage tank is equipped with a first drive motor (21) for driving the first spiral conveyor rod to rotate. The second chemical agent storage tank is rotatably connected to a second spiral conveyor rod (31) for adding materials into the second mixing cylinder. The upper end of the second chemical agent storage tank is equipped with a second drive motor (32) for driving the second spiral conveyor rod to rotate. The lower part of both the first chemical agent storage tank and the second chemical agent storage tank is provided with a conical inner bottom (39), and the lower end of each conical inner bottom is provided with a feeding pipe (40). The upper end of both the first mixing cylinder and the second mixing cylinder is open. The first spiral conveying rod and the second spiral conveying rod both include a spiral guide rod in the corresponding conical inner bottom and a spiral feeding rod in the corresponding feeding pipe. The outer diameter of each spiral guide rod is larger than the outer diameter of the corresponding spiral feeding rod.

5. A waste gas treatment system for spray painting according to any one of claims 1 or 4, characterized in that: Both the first mixing cylinder and the second mixing cylinder are provided with a connecting shaft (41), and each connecting shaft is provided with multiple spiral guide blades (42) on its outer periphery. Each spiral guide blade has a gap between itself and the inner wall of the first mixing cylinder or the inner wall of the second mixing cylinder.

6. The exhaust gas treatment system for spray painting according to claim 1, characterized in that: Both the first chemical agent storage tank and the second chemical agent storage tank are provided with a feeding port (38) at the top.

7. The exhaust gas treatment system for spray painting according to claim 1, characterized in that: Each atomizing nozzle has a connecting pipe (10) at the end away from its nozzle. Each connecting pipe is provided with a liquid inlet chamber (11) connected to the corresponding high-pressure nozzle and an air inlet chamber (12) connected to the corresponding high-pressure air pipe.

8. The exhaust gas treatment system for spray painting according to claim 1, characterized in that: The sedimentation filter is equipped with a replaceable coarse filter element (51), the particulate filter is equipped with a replaceable ultrafiltration filter element (52), and the dissolved salt filter is equipped with a replaceable reverse osmosis filter element (53).

9. The exhaust gas treatment system for spray painting according to claim 1, characterized in that: A solenoid valve (36) is installed on the drain pipe, and a liquid level sensor (37) for monitoring the liquid level in the lower part of the demister is installed in the lower part of the demister.

10. The exhaust gas treatment system for spray painting according to claim 1, characterized in that: The second mixing cylinder is connected to a pH alkali sensor (33) for monitoring the pH value of the solution inside it.

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