An industrial waste gas purification system and purification process

Abstract

The present application relates to the technical field of waste gas treatment, and discloses an industrial waste gas purification system and a purification process, which comprises, in sequence, a spray main pipe unit, a vertical spray unit, a multi-pass condensation unit, an electrostatic tower dust removal unit, a discharge unit and a control system, a waste heat recovery unit is arranged on the upstream side of the spray main pipe unit, and a plasma deodorization unit or a micro-nano bubble deodorization unit is arranged between the electrostatic tower dust removal unit and the discharge unit. The purification process is performed in the order of waste heat recovery, main pipe spraying, vertical spraying, multi-pass condensation, pulse electrostatic dust removal, plasma deodorization or micro-nano bubble deodorization. The present application improves the heat exchange efficiency by placing the waste heat recovery unit in the front position, reduces the energy consumption of the subsequent cooling treatment, improves the dust removal efficiency and reduces the energy consumption by using the nanosecond pulse high-voltage electrostatic dust removal technology, and realizes efficient removal of pollutants by combining plasma deodorization or micro-nano bubble deodorization, and has the characteristics of energy saving, high efficiency, safety and reliability.

Description

Technical Field

[0001] This invention relates to the field of waste gas treatment technology, and in particular to an industrial waste gas purification system and purification process. Background Technology

[0002] Industrial production processes, such as textile finishing, emit large amounts of complex waste gases, including particulate matter (PM2.5, PM10), VOCs, formaldehyde, benzene compounds, and malodorous substances. Direct emission without effective treatment will cause serious harm to the atmospheric environment and human health. In terms of waste heat utilization, traditional processes often place waste gas treatment before waste heat recovery. Taking the waste gas treatment of stenters as an example, the initial temperature of this type of waste gas can reach 160-180℃, and it contains a large amount of dust, grease, and sticky substances. When conventional heat exchangers are used for waste heat recovery, these impurities in the waste gas easily adhere to the surface of the heat exchanger, causing a significant decrease in heat exchange efficiency. For example, plate heat exchangers, due to their narrow heat exchange channels, are prone to blockage when treating waste gas containing fibers or large particles, which not only increases resistance but also significantly reduces the heat transfer coefficient. To reduce the condensation of oil fume particles, although the waste gas temperature after heat exchange can be maintained at 100±5℃ by controlling the waste gas flow rate and wind speed, the waste heat recovery rate is still low, while the equipment investment and recovery costs remain high, seriously limiting the widespread application of waste heat recovery technology. In existing dust removal technologies, electrostatic precipitators powered by industrial frequency or high frequency power supplies are not very effective at removing ultrafine dust (e.g., particles ≤2.5μm in diameter) and dust with high resistivity. These dust particles are difficult to charge and capture effectively in conventional electric fields, resulting in low dust removal efficiency. Furthermore, traditional electrostatic precipitators consume a lot of energy and are prone to flashover during operation. Once a flashover occurs, it not only affects the dust removal effect but may also cause fires and other safety hazards, endangering production safety. Traditional deodorization technologies also have many drawbacks. While adsorption methods (such as activated carbon adsorption) can remove odors from exhaust gases to some extent, they suffer from limited adsorption capacity, easy saturation, and the need for frequent adsorbent replacement. Furthermore, improper treatment of adsorbed pollutants can easily cause secondary pollution. Combustion methods can decompose some pollutants, but they have high operating costs, consume a large amount of energy, and are ineffective in treating low-concentration VOCs and malodorous substances, making it difficult to meet increasingly stringent environmental protection requirements. Summary of the Invention

[0003] The purpose of this invention is to provide an industrial waste gas purification system and purification process, which aims to solve the problems of low waste heat recovery efficiency, unsatisfactory dust removal and deodorization effects, and excessive energy consumption in existing industrial waste gas treatment technologies.

[0004] The above-mentioned technical objective of the present invention is achieved through the following technical solution: An industrial waste gas purification system includes, in sequence, a spray main unit, a vertical spray unit, a multi-pass condensation unit, an electrostatic precipitator unit, a discharge unit, and a control system. A waste heat recovery unit is provided on the upstream side of the spray main unit; The waste heat recovery unit includes multiple heat exchangers, an air inlet duct, a return air duct, an exhaust duct, and an outlet duct arranged in series. The heat outlet of the upstream heat exchanger is connected to the heat inlet of its adjacent downstream heat exchanger. The cold outlet of the downstream heat exchanger is connected to the cold inlet of its adjacent upstream heat exchanger. The air inlet duct is connected to the cold inlet of the downstream heat exchanger, and the return air duct is connected to the cold outlet of the upstream heat exchanger. The other end of the return air duct extends into the stenter. The exhaust duct connects the stenter to the heat inlet of the upstream heat exchanger, and the outlet duct connects the heat outlet of the downstream heat exchanger and the spray main unit. The exhaust gas (approximately 140-160℃) generated by the stenter enters the upstream heat exchanger through the exhaust pipe. The exhaust gas then passes through the downstream heat exchanger before being discharged through the outlet pipe. Fresh air enters the downstream heat exchanger through the inlet pipe, and then flows sequentially to the upstream heat exchanger. As the fresh air passes through multiple heat exchangers, it exchanges heat with the exhaust gas, achieving a tiered heating effect. The fresh air is gradually heated from room temperature to 110-120℃, and then enters the stenter through the return air pipe, where it only needs slight heating to reach the stenting process temperature of 210-220℃. Simultaneously, by performing pre-heat exchange on the exhaust gas, its temperature is reduced, thus lowering the energy consumption for exhaust gas treatment and cooling in the downstream stages.

[0005] The spray manifold unit includes a horizontally arranged main pipe connected to the exhaust pipe. Several first spray heads are installed in the upper space of the main pipe. These spray heads cool the exhaust gas passing through the main pipe to approximately 100 degrees Celsius. The spraying also removes large particles of lint and other impurities, as well as some oil, from the exhaust gas. Simultaneously, the sprayed water cleans the pipes and provides fire safety by preventing sparks from entering the downstream side. The water generated from the spraying process is treated and then flows back into the first cooling tower. The first cooling tower cools the water before pumping it into the first spray heads.

[0006] The vertical spray unit includes a spray dust removal tower. The bottom of the spray dust removal tower is connected to a first connecting pipe that connects to the main pipe. The spray dust removal tower contains multiple layers of second spray heads arranged in a spiral pattern, forming a fine water curtain that effectively captures large dust particles with a diameter ≥10μm and oily substances in the exhaust gas. Simultaneously, an oil-water separation component separates the sprayed liquid to prevent secondary pollution from oil. During the pollutant removal process, this device can reduce the exhaust gas temperature from 100±5℃ to 50-70℃, creating suitable conditions for subsequent treatment. The water at the bottom of the spray dust removal tower, after treatment, flows back into the second cooling tower. The second cooling tower cools the water and then pumps it back into the second spray heads.

[0007] The multi-pass condensation unit includes a condensation chamber containing multiple linearly arranged condenser fins. The condensation chamber is connected to the upper part of a spray dust collector via a second connecting pipe. Exhaust gas exiting the spray dust collector enters the condensation chamber through the second connecting pipe, and then sequentially passes through the multiple condenser fins for stepped cooling, condensing the water vapor in the exhaust gas and eliminating most of the water vapor. The condenser fins are connected to a cooling system.

[0008] The electrostatic precipitator dust removal unit includes an electrostatic precipitator body and barbed cathode wires installed inside the electrostatic precipitator body. Each barbed cathode wire is inserted into a corresponding anode cylinder. The barbed cathode wires and anode cylinders are electrically connected to a first nanowave pulse high-voltage power supply. The anode cylinder is connected to the positive terminal of the first nanowave pulse high-voltage power supply and is effectively grounded, while the barbed cathode wires are connected to the negative terminal of the first nanowave pulse high-voltage power supply. The lower part of the electrostatic precipitator body is connected to the outlet of the condensation chamber through a third connecting pipe. The condensed waste gas enters the bottom of the electrostatic precipitator body through the third connecting pipe and then passes through the anode tube. A first nanowave pulse high-voltage power supply is used, paired with specially designed barbed cathode wires. The output voltage range of the first nanowave pulse high-voltage power supply is 40,000-200,000V, and the pulse frequency reaches 60,000-80,000 times / second. Its working principle is as follows: under the action of a high-voltage, high-frequency pulsed electric field, gas molecules are ionized, generating a large number of high-energy electrons and ions. These high-energy particles collide with fine particulate matter (≤10μm) in the exhaust gas, causing the particles to rapidly become charged. Under the influence of the electric field, the charged particles quickly move towards the anode cylinder and are adsorbed, thus achieving efficient dust removal. Compared with traditional electrostatic precipitators, the pulsed electric field generated by the first nanowave pulse high-voltage power supply can more effectively overcome the charging barrier of dust, making ultrafine dust and high resistivity dust easier to charge, greatly improving dust removal efficiency. Simultaneously, its millisecond-level flashover control system can monitor fluctuations in the electric field voltage and current in real time. In the event of a flashover, it can quickly cut off the current and restore the voltage within milliseconds, effectively preventing safety accidents such as fires. Furthermore, its operating energy consumption is only 60%-70% of that of traditional power frequency power supplies.

[0009] The exhaust unit includes an exhaust fan and a chimney. The exhaust fan is connected to the electrostatic tower body and is used for exhaust gas extraction in the entire exhaust gas purification system.

[0010] The control system consists of a PLC controller and temperature sensors, dust concentration sensors, and VOCs detectors installed in each unit. Temperature sensors monitor the temperature of the exhaust gas in each treatment unit in real time. The dust concentration sensors and VOCs detectors are used to detect the concentrations of dust and volatile organic compounds in the exhaust gas, respectively. Based on the data fed back from the sensors, the PLC controller automatically adjusts parameters such as the exhaust fan speed, spray volume, and the first nanowave pulse high-voltage power supply to achieve intelligent and stable operation of the system.

[0011] Preferably, the heat exchanger includes an outer shell and an inner shell, with two annular partitions fixed between the outer shell and the inner shell; the two annular partitions divide the space between the outer shell and the inner shell into a heat inlet, an intermediate cavity and a heat outlet; The inner shell is fixed with an inner support plate and an outer partition plate at each end. Multiple arrayed heat exchange tubes are connected between the two inner support plates. The two inner support plates and the inner shell form a heat exchange cavity. The inner support plate, the outer partition plate, and the inner shell on the same side form a flow distribution cavity. The cold inlet is formed on the outer partition plate on the downstream side, and the cold outlet is formed on the outer partition plate on the upstream side. One of the outer partition plates of two adjacent heat exchangers is attached to each other, and the outer shell end faces of two adjacent heat exchangers are attached and sealed and fixedly connected. The upper side wall of the inner shell has a waste gas inlet connected to the heat inlet on the left end, and the lower side wall of the inner shell has a waste gas outlet connected to the heat outlet on the right end.

[0012] The exhaust gas entering the upstream exhaust gas inlet through the exhaust pipe enters the heat exchange chamber through the exhaust gas inlet. After heat exchange, it enters the exhaust gas outlet through the exhaust gas outlet. The exhaust gas outlet is connected to the exhaust gas inlet of the adjacent downstream heat exchanger, allowing the exhaust gas to exchange heat sequentially through the heat exchange chambers of each heat exchanger. Fresh air enters the downstream distribution chamber of the downstream heat exchanger through the air inlet pipe, and then is distributed to each heat exchange tube. Through the heat exchange tube, the fresh air exchanges heat with the exhaust gas, performing a first-stage heating process. The fresh air then enters the upstream distribution chamber of the downstream heat exchanger, where it mixes to achieve a uniform temperature. It then enters the next heat exchanger through the vent for a second-stage heating process, and so on. After being heated through multiple heat exchangers and multiple stages, the fresh air is discharged into the stenter through the return air duct.

[0013] Preferably, the heat exchange tube is a tapered tube, and the diameter of the inlet end of the heat exchange tube is smaller than the diameter of the outlet end of the heat exchange tube.

[0014] Fresh air flow direction: It enters from the small end of the heat exchange tube and flows out from the large end. The small end of the tapered tube has a small cross-section and high flow velocity, which can quickly remove the heat initially absorbed. As the air flows towards the large end, the cross-section increases and the flow velocity decreases, which prolongs the residence time in the high-temperature zone (corresponding to the exhaust gas inflow side) and fully exchanges heat with the high-temperature section of the exhaust gas to match the "gradient heating" requirement.

[0015] Waste gas flow direction: It flows from the outer wall of the large end of the heat exchange tube to the outer wall of the small end. The temperature of the waste gas gradually decreases with the flow. The outer wall of the large end corresponds to the waste gas inlet. The temperature difference between the waste gas and the air inside the tube is large, which can release heat efficiently. When it flows to the small end, the temperature of the waste gas decreases. At this time, although the air inside the tube has been preheated, a certain temperature difference can still be maintained to avoid energy waste.

[0016] Preferably, the inner shell is provided with multiple fire extinguishing branch pipes arranged parallel to the heat exchange tubes, and the fire extinguishing branch pipes are formed with several radial injection holes; each row of fire extinguishing branch pipes is connected to a fire extinguishing main pipe, and multiple fire extinguishing main pipes extend through the outer end of the inner shell and are connected to a distributor, the distributor is connected to a steam pipe, the steam pipe is equipped with an electromagnetic on / off valve, and the steam pipe is connected to a steam source; the heat exchange chamber is provided with a second temperature sensor, the second temperature sensor, the electromagnetic on / off valve, and a PLC controller are electrically connected. The second temperature sensor is used to detect the temperature in the heat exchange chamber. If the detected temperature in the heat exchange chamber is much higher than the exhaust gas temperature, there is a possibility of fire in the heat exchange chamber. At this time, the PLC controller controls the electromagnetic on / off valve to open, and steam enters the distributor through the steam pipe, and then is distributed to multiple fire extinguishing main pipes by the distributor. The steam in the fire extinguishing branch pipes is again distributed to the fire extinguishing branch pipes, and the steam in the fire extinguishing branch pipes is ejected through the radial injection holes, thereby extinguishing the fire in the heat exchange chamber.

[0017] Preferably, a Z-shaped baffle is provided on one side of the exhaust gas inlet and the exhaust gas outlet. Multiple nylon pins are sleeved on the Z-shaped baffle and inserted into the inner wall of the inner shell. One end of the Z-shaped baffle is inserted into one of the annular partitions, and a compression spring is clamped between the Z-shaped baffle and the other annular partition.

[0018] If steam extinguishing fails to extinguish the fire, the heat exchange chamber will catch fire, causing the temperature inside to rise rapidly to the melting point of nylon. The nylon will melt, and the Z-shaped baffle will lose its blocking function. Under the action of the compression spring, the Z-shaped baffle will move, blocking the exhaust gas inlet or outlet, or both, thus cutting off the exhaust gas passage and preventing flames from entering the downstream exhaust gas treatment unit. This effectively protects downstream components and significantly reduces losses. The exhaust gas temperature from the stenter is between 140-160℃, while the melting point of nylon is approximately 260℃. Below 200℃, nylon is solid and stable, and will not soften or deform, effectively blocking the Z-shaped baffle during normal operation.

[0019] Preferably, a plasma deodorization unit is provided between the electrostatic tower dust removal unit and the discharge unit; The plasma deodorization unit includes a reaction cylinder containing multiple vertically arranged dust collection cylinders. Each dust collection cylinder contains a discharge electrode. The dust collection cylinders and discharge electrodes are electrically connected to a second nanowave pulse high-voltage power supply. The ends of the multiple reaction cylinders are fitted onto a sealing plate, which is fixed within the reaction cylinder. The discharge electrode is electrically connected to the negative terminal of the second nanowave pulse high-voltage power supply, and the dust collection cylinders are electrically connected to the positive terminal of the second nanowave pulse high-voltage power supply and grounded. The upper end of the reaction cylinder is connected to the outlet of the electrostatic tower body via a fourth connecting pipe, and the lower end of the reaction cylinder is connected to an exhaust fan via a fifth connecting pipe. Exhaust gas exiting the electrostatic tower body enters the reaction cylinder through the fourth connecting pipe and then passes through the multiple dust collection cylinders. During this passage, the discharge electrode establishes an ionization electric field, and the dust collection cylinders establish an adsorption electric field. When the exhaust gas enters the dust collection cylinders, under the influence of the ionization electric field, molecules such as nitrogen and oxygen in the air are ionized, forming plasma containing high-energy electrons, O, OH, and other free radicals. These active particles possess extremely high chemical activity, enabling them to undergo a series of complex chemical reactions with VOCs and odor molecules in exhaust gases. For example, high-energy electrons collide with odor molecules (such as hydrogen sulfide and ammonia), breaking their chemical bonds and decomposing them into smaller molecules; free radicals react with VOC molecules through oxidation, gradually degrading them into harmless substances such as CO2 and H2O. An adsorption electric field further adsorbs any unreacted pollutants, ensuring effective deodorization. This unit achieves a VOCs degradation efficiency of ≥90%, an odor removal rate of ≥95%, and does not generate secondary pollution.

[0020] Another preferred method of deodorization is to provide a micro-nano bubble deodorization unit between the electrostatic tower dust removal unit and the discharge unit; The micro-nano bubble deodorization unit includes a deodorization tank and a micro-nano bubble generator. The bubble outlet of the micro-nano bubble generator extends into the lower part of the deodorization tank. The deodorization tank is provided with multiple layers of horizontally arranged porous sieve plates and guide plates. The guide plates are inclined between adjacent porous sieve plates.

[0021] An industrial waste gas purification process includes the following steps: Step 1: Waste heat recovery in stages. The 140-160℃ exhaust gas generated by the stenter is introduced into the upstream heat exchanger of the waste heat recovery unit through the exhaust pipe. The exhaust gas flows through the heat exchange chambers of each downstream heat exchanger in sequence, exchanging heat with the fresh air in the heat exchange tubes. The fresh air enters the downstream heat exchanger from the air inlet pipe, flows upstream through multiple heat exchangers, and is heated to 110-120℃ through multi-stage heating before entering the stenter through the return air pipe. After heat exchange, the exhaust gas enters the spray main unit through the exhaust pipe. Step 2: Main pipe spray pretreatment. After the exhaust gas enters the horizontal main pipe, it is sprayed by the first spray head to reduce the temperature to 100±5℃. After removing large particles of cotton and oil stains from the exhaust gas, the exhaust gas enters the spray dust removal tower. Step 3: Vertical spray deep purification, a water curtain is formed by the multi-layer spiral distribution of the second spray head to remove large dust particles and grease with a diameter ≥10μm in the exhaust gas. After the exhaust gas temperature drops to 50-70℃, it enters the condensation box. Step 4: Multi-pass condensation and dehydration. The exhaust gas passes through multiple linearly arranged condenser fins in sequence for stepped cooling. The exhaust gas after dehydration by the condenser fins enters the electrostatic tower body. Step 5: High-efficiency dust removal in electrostatic tower. The first nanowave pulse high-voltage power supply generates corona discharge through the barbed cathode wire, which charges fine particles ≤10μm and adsorbs them by the anode cylinder. The voltage of the first nanowave pulse high-voltage power supply is 40000-200000V and the discharge frequency is 60000-80000 times / second. Step 6: Discharge. The treated exhaust gas is discharged through a chimney by a blower.

[0022] As a preferred option, the process also includes step 5-1: plasma deep deodorization. The exhaust gas after being dusted by the electrostatic tower enters the reaction cylinder of the plasma deodorization unit. In the electric field formed by the dust collection cylinder and the discharge electrode, the second nanowave pulse high voltage power supply ionizes the air through the electric field to generate non-equilibrium plasma, which degrades VOCs and odor molecules into CO2 and H2O. The VOCs degradation efficiency is ≥90%, and the odor concentration removal rate is ≥95%. The treated exhaust gas then enters step 6 for emission.

[0023] Another preferred deodorization process also includes step 5-2: micro-nano bubble deodorization. The dust-removed waste gas enters the deodorization tank, and micro-nano bubbles with a diameter of 50-500nm are introduced into the deodorization tank through a micro-nano bubble generator. When the waste gas comes into contact with the micro-nano bubbles, the micro-nano bubbles burst to generate a high-temperature and high-pressure environment and hydroxyl free radicals, which react with VOCs and malodor molecules to undergo oxidation. The treated waste gas then enters step 6 for emission.

[0024] The outstanding effects of this invention are: Compared with existing technologies, by setting up a waste heat recovery unit upstream of the spray main unit and using multiple heat exchangers in series to achieve cascade heat exchange between exhaust gas and fresh air, the waste heat recovery rate can be improved and the energy consumption of the stenter can be reduced. At the same time, the energy consumption of downstream cooling treatment can be reduced.

[0025] The conical heat exchange tube design allows fresh air to enter from the small end and exit from the large end, while exhaust gas flows from the outer wall of the large end to the outer wall of the small end, which can further increase the heat exchange time and heat exchange effect of the fresh air.

[0026] The electrostatic tower dust removal unit uses a combination of first nanowave pulse high-voltage power supply and barbed cathode wire to achieve efficient removal of fine particles ≤10μm. At the same time, the millisecond-level flashover control system reduces the risk of fire, and the operating energy consumption is only 60%-70% of that of traditional power frequency power supply.

[0027] The plasma deodorization unit uses a dust collection cylinder and discharge electrode to form an ionization electric field, generating non-equilibrium plasma to degrade VOCs (efficiency ≥90%) and malodorous molecules (removal rate ≥95%), thus avoiding secondary pollution. Alternatively, the micro-nano bubble deodorization unit combines 50-500nm bubbles with porous sieve plates and flow guide plates, utilizing the hydroxyl radicals generated by bubble rupture to achieve efficient oxidation and degradation of VOCs (efficiency ≥92%) and malodorous substances (removal rate ≥96%), while also enabling solution recycling and cost reduction.

[0028] The waste heat recovery unit's fire extinguishing branch pipe and Z-shaped baffle provide dual protection, achieving rapid fire extinguishing and cutting off the exhaust gas passage when the heat exchange chamber experiences abnormal temperature rise, thus protecting the safety of downstream equipment. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the purification system of the present invention; Figure 2 This is a schematic diagram of the waste heat recovery unit of the present invention; Figure 3 This is a schematic diagram of the heat exchanger of the present invention; Figure 4 for Figure 3 A sectional view of AA; Figure 5 This is a schematic diagram of the structure of the plasma deodorization unit of the present invention; Figure 6 This is a schematic diagram of another purification system according to the present invention; Figure 7 This is a general process flow diagram of the present invention.

[0030] Reference numerals: 1. Spray main pipe unit; 2. Vertical spray unit; 21. Spray dust removal tower; 22. First connecting pipe; 3. Multi-pass condensing unit; 31. Condensing box; 32. Condensing fin assembly; 33. Second connecting pipe; 4. Electrostatic tower dust removal unit; 41. Electrostatic tower body; 42. Barbed cathode wire; 43. Third connecting pipe; 5. Discharge unit; 51. Exhaust fan; 52. Chimney; 6. Waste heat recovery unit; 61. Heat exchanger; 62. Inlet duct; 63. Return duct; 64. Exhaust duct; 65. Outlet duct; 611. Outer shell; 612. Inner shell; 613. Annular baffle; 614. Inner support plate; 615. Outer baffle; 616. Heat exchange tube; 701. Extinguishing... 702. Fire branch pipe; 703. Fire extinguishing main pipe; 704. Diverter; 705. Steam pipe; 706. Electromagnetic on / off valve; 707. Nylon pin; 708. Compression spring; 709. Z-type baffle; 6001. Hot inlet; 6002. Hot outlet; 601. Cold inlet; 602. Cold outlet; 603. Intermediate cavity; 604. Heat exchange cavity; 605. Diversion and distribution cavity; 606. Exhaust gas inlet; 607. Exhaust gas outlet; 8. Plasma deodorization unit; 81. Reaction cylinder; 82. Dust collection cylinder; 83. Discharge electrode; 84. Fourth connecting pipe; 85. Fifth connecting pipe; 9. Micro-nano bubble deodorization unit; 91. Deodorization tank; 92. Micro-nano bubble generator; 93. Porous sieve plate; 94. Guide plate. Detailed Implementation

[0031] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0032] The following is for reference Figures 1 to 7 The present invention will be described as follows: Example 1

[0033] An industrial waste gas purification system, such as Figure 1 , Figure 2 As shown, it includes a spray main pipe unit 1, a vertical spray unit 2, a multi-pass condensation unit 3, an electrostatic tower dust removal unit 4, a discharge unit 5, and a control system arranged in sequence. A waste heat recovery unit 6 is provided on the upstream side of the spray main pipe unit 1.

[0034] The waste heat recovery unit 6 includes multiple heat exchangers 61 connected in series, an air inlet duct 62, a return air duct 63, an exhaust duct 64, and an air outlet duct 65. The heat outlet 602 of the upstream heat exchanger 61 is connected to the heat inlet 601 of its adjacent downstream heat exchanger 61. The cold outlet 604 of the downstream heat exchanger 61 is connected to the cold inlet 603 of its adjacent upstream heat exchanger 61. The air inlet duct 62 is connected to the cold inlet 603 of the downstream heat exchanger 61, and the return air duct 63 is connected to the cold outlet 604 of the upstream heat exchanger 61. The other end of the return air duct 63 extends into the stenter. The exhaust duct 64 connects the stenter to the heat inlet 601 of the upstream heat exchanger 61, and the air outlet duct 65 connects the heat outlet 602 of the downstream heat exchanger 61 and the spray main unit. The exhaust gas (approximately 140-160℃) generated by the stenter enters the upstream heat exchanger 61 through exhaust pipe 64. The exhaust gas then passes through downstream heat exchangers 61 and is discharged through outlet pipe 65. Fresh air enters the downstream heat exchanger 61 through inlet pipe 62, and then flows sequentially to upstream heat exchangers 61. As the fresh air passes through multiple heat exchangers 61, it exchanges heat with the exhaust gas, achieving a tiered heating effect. The fresh air can be gradually heated from room temperature to 110-120℃, and then enters the stenter through return air pipe 63, where it only needs slight heating to reach the stenting process temperature of 210-220℃. Simultaneously, by performing pre-heat exchange on the exhaust gas, its temperature is reduced, thus lowering the energy consumption for exhaust gas treatment and cooling in downstream stages.

[0035] The spray manifold unit 1 includes a horizontally arranged manifold connected to the exhaust pipe 65. Several first spray heads are installed in the upper space of the manifold. The spray heads cool the exhaust gas passing through the manifold to approximately 100 degrees Celsius, spraying away large particles of lint and other impurities, as well as some oil stains. Simultaneously, the sprayed water cleans the pipes and also provides fire safety by preventing sparks from entering the downstream side. The water generated by the spraying within the pipes is treated and then flows back into the first cooling tower. The first cooling tower cools the water before pumping it into the first spray heads.

[0036] The vertical spray unit 2 includes a spray dust removal tower 21. The bottom of the spray dust removal tower 21 is connected to a first connecting pipe 22, which is connected to the main pipe. The spray dust removal tower 21 contains multiple layers of second spray heads arranged in a spiral pattern, forming a fine water curtain that effectively captures large dust particles with a diameter ≥10μm and oily substances in the exhaust gas. Simultaneously, an oil-water separation component separates the sprayed liquid to prevent secondary pollution from oil. During the pollutant removal process, this device can reduce the exhaust gas temperature from 100±5℃ to 50-70℃, creating suitable conditions for subsequent treatment. The water at the bottom of the spray dust removal tower 21, after treatment, flows back into the second cooling tower. The second cooling tower cools the water and then pumps it back into the second spray heads.

[0037] The multi-pass condensation unit 3 includes a condensation chamber 31, which contains multiple linearly arranged condenser fin groups 32. The condensation chamber 31 is connected to the upper part of the spray dust removal tower 21 via a second connecting pipe 33. The exhaust gas exiting the spray dust removal tower 21 enters the condensation chamber 31 through the second connecting pipe 33, and then passes through the multiple condenser fin groups 32 in sequence for stepped cooling, condensing the water vapor in the exhaust gas and eliminating most of the water vapor. The condenser fin groups 32 are connected to a cooling system.

[0038] The electrostatic precipitator dust removal unit 4 includes an electrostatic precipitator body 41 and barbed cathode wires 42 disposed within the electrostatic precipitator body 41. Each barbed cathode wire 42 is inserted into a corresponding anode cylinder. The barbed cathode wires 42 and the anode cylinders are electrically connected to a first nanowave pulse high-voltage power supply. The anode cylinder is connected to the positive terminal of the first nanowave pulse high-voltage power supply and is effectively grounded, while the barbed cathode wires 42 are connected to the negative terminal of the first nanowave pulse high-voltage power supply. The lower part of the electrostatic precipitator body 41 is connected to the outlet of the condensation chamber 31 via a third connecting pipe 43. The condensed exhaust gas enters the bottom of the electrostatic precipitator body 41 through the third connecting pipe 43 and then passes through the anode tube. A first nanowave pulse high-voltage power supply is used, paired with specially designed barbed cathode wires 42. The output voltage range of the first nanowave pulse high-voltage power supply is 40,000-200,000V, and the pulse frequency reaches 60,000-80,000 times / second. Its working principle is as follows: Under the action of a high-voltage, high-frequency pulsed electric field, gas molecules are ionized, generating a large number of high-energy electrons and ions. These high-energy particles collide with fine particulate matter (≤10μm) in the exhaust gas, causing the particles to rapidly become charged. Under the action of the electric field force, the charged particles quickly move towards the anode cylinder and are adsorbed, thereby achieving efficient dust removal. Compared with traditional electrostatic dust removal technology, the pulsed electric field generated by the first nanowave pulsed high-voltage power supply can more effectively overcome the charging barrier of dust, making ultrafine dust and high resistivity dust easier to charge, greatly improving dust removal efficiency; at the same time, its equipped millisecond-level flashover control system can monitor the fluctuation of electric field voltage and current in real time. Once a flashover occurs, it can quickly cut off the current and restore the voltage within milliseconds, effectively avoiding safety accidents such as fires, and its operating energy consumption is only 60%-70% of that of traditional power frequency power supplies.

[0039] The discharge unit 5 includes an exhaust fan 51 and a chimney 52. ​​The exhaust fan 51 is connected to the electrostatic tower body 41 and is used for exhaust gas extraction in the entire exhaust gas purification system.

[0040] The control system consists of a PLC controller and temperature sensors, dust concentration sensors, and VOCs detectors installed in each unit. Temperature sensors monitor the temperature of the exhaust gas in each treatment unit in real time. The dust concentration sensors and VOCs detectors are used to detect the concentrations of dust and volatile organic compounds in the exhaust gas, respectively. Based on the data fed back from the sensors, the PLC controller automatically adjusts parameters such as the fan speed, spray volume, and the first nanowave pulse high-voltage power supply to achieve intelligent and stable operation of the system.

[0041] like Figure 3As shown, the heat exchanger 61 includes an outer shell 611 and an inner shell 612. Annular partitions 613 are fixed between the outer shell 611 and the inner shell 612. The two annular partitions 613 divide the space between the outer shell 611 and the inner shell 612 into the heat inlet 601, the intermediate cavity 605 and the heat outlet 602. The inner shell 612 is fixed with an inner support plate 614 and an outer partition plate 615 at each end. Multiple arrayed heat exchange tubes 616 are connected between the two inner support plates 614. The two inner support plates 614 and the inner shell 612 form a heat exchange cavity 606. The inner support plate 614, the outer partition plate 615 and the inner shell 612 on the same side form a flow distribution cavity 607. The cold inlet 603 is formed on the outer partition plate 615 on the downstream side and the cold outlet 604 is formed on the outer partition plate 615 on the upstream side. One of the outer partition plates 615 of two adjacent heat exchangers 61 are attached to each other, and the end faces of the outer shells 611 of two adjacent heat exchangers 61 are attached and sealed and fixedly connected. The upper side wall of the inner shell 612 has a waste gas inlet 608 that communicates with the heat inlet 601 formed on the left end, and the lower side wall of the inner shell 612 has a waste gas outlet 609 that communicates with the heat outlet 602 formed on the right end.

[0042] The exhaust gas entering the upstream exhaust gas inlet chamber through the exhaust pipe 64 enters the heat exchange chamber 606 through the exhaust gas inlet 608. After heat exchange, it enters the exhaust gas outlet chamber through the exhaust gas outlet 609. The exhaust gas outlet chamber is connected to the exhaust gas inlet chamber of the adjacent downstream heat exchanger 61, so that the exhaust gas exchanges heat through the heat exchange chamber 606 of each heat exchanger 61 in sequence. Fresh air enters the downstream distribution chamber 607 of the downstream heat exchanger 61 through the inlet duct 62, and then is distributed to each heat exchange tube 616. The heat exchange tube 616 exchanges heat with the exhaust gas, and after the fresh air is heated in the first stage, it enters the upstream distribution chamber 607 of the downstream heat exchanger 61. At this time, the air heated in the first stage is mixed in the distribution chamber 607 to make the temperature uniform, and then enters the next heat exchanger 61 through the corresponding cold outlet 604 and cold inlet 603 for the second stage of heating. And so on. After being heated in multiple stages by multiple heat exchangers 61, the fresh air is discharged into the stenter through the return air duct 63.

[0043] The heat exchange tube 616 is a tapered tube, and the diameter of the inlet end of the heat exchange tube 616 is smaller than the diameter of the outlet end of the heat exchange tube 616.

[0044] Fresh air flow direction: It enters from the small end of the heat exchange tube 616 and flows out from the large end. The small end of the tapered tube has a small cross-section and high flow velocity, which can quickly remove the heat initially absorbed. As the air flows towards the large end, the cross-section increases and the flow velocity decreases, which prolongs the residence time in the high-temperature zone (corresponding to the exhaust gas inflow side) and fully exchanges heat with the high-temperature section of the exhaust gas to match the "gradient heating" requirement.

[0045] Waste gas flow direction: It flows from the outer wall of the large end of heat exchange tube 616 to the outer wall of the small end. The temperature of the waste gas gradually decreases with the flow. The outer wall of the large end corresponds to the waste gas inlet, and the heat exchange temperature difference with the air inside the tube is large, which can release heat efficiently. When it flows to the small end, the temperature of the waste gas decreases. At this time, although the air inside the tube has been preheated, a certain heat exchange temperature difference can still be maintained to avoid energy waste.

[0046] like Figure 4 As shown, the inner shell 612 is provided with a plurality of fire extinguishing branch pipes 701 arranged parallel to the heat exchange pipes 616, and the fire extinguishing branch pipes 701 are formed with a plurality of radial spray holes; each row of fire extinguishing branch pipes 701 is connected to a fire extinguishing main pipe 702, and the multiple fire extinguishing main pipes 702 extend through the outer end of the inner shell 612 and are connected to a distributor 703, the distributor 703 is connected to a steam pipe 704, the steam pipe 704 is provided with an electromagnetic on / off valve 705, and the steam pipe 704 is connected to a steam source; the heat exchange chamber 606 is provided with a second temperature sensor, and the second temperature sensor, the electromagnetic on / off valve 705, and the PLC controller are electrically connected. The second temperature sensor is used to detect the temperature inside the heat exchange chamber 606. If the temperature of the heat exchange chamber 606 is much higher than the temperature of the exhaust gas, there is a possibility that the heat exchange chamber 606 is on fire. At this time, the PLC controller controls the solenoid on / off valve 705 to open, and the steam enters the distributor 703 through the steam pipe 704. Then, the steam is distributed to multiple fire extinguishing main pipes 702 through the distributor 703. The steam in the fire extinguishing branch pipes 701 is again distributed to the fire extinguishing branch pipes 701. The steam in the fire extinguishing branch pipes 701 is sprayed out through the radial injection holes, thereby extinguishing the fire in the heat exchange chamber 606.

[0047] like Figure 3 As shown, a Z-shaped baffle 708 is provided on one side of the exhaust gas inlet 608 and the exhaust gas outlet 609. A plurality of nylon pins 706 are sleeved on the Z-shaped baffle 708 and inserted into the inner wall of the inner shell 612. One end of the Z-shaped baffle 708 is inserted into one of the annular partitions 613, and a compression spring 707 is clamped between the Z-shaped baffle 708 and the other annular partition 613.

[0048] If steam extinguishing fails to extinguish the fire, the temperature inside the heat exchange chamber 606 will rapidly rise to the melting point of nylon due to the fire. The nylon pin 706 will melt, and the Z-shaped baffle 708 will lose its blocking function. Under the action of the compression spring 707, the Z-shaped baffle 708 will move, blocking either the exhaust gas inlet 608 or the exhaust gas outlet 609, or both. This cuts off the exhaust gas passage, preventing the flame from entering the downstream exhaust gas treatment unit, effectively protecting downstream components and significantly reducing losses. The exhaust gas temperature from the stenter is between 140-160℃, while the melting point of nylon is approximately 260℃. Below 200℃, nylon is solid and stable, and will not soften or deform, effectively blocking the Z-shaped baffle 708 during normal operation. Example 2

[0049] Based on Example 1, such as Figure 1 As shown, a plasma deodorization unit 8 is provided between the electrostatic precipitator dust removal unit 4 and the discharge unit 5.

[0050] like Figure 5 As shown, the plasma deodorization unit 8 includes a reaction cylinder 81, inside which are multiple vertically arranged dust collection cylinders 82. Each dust collection cylinder 82 contains a discharge electrode 83. The dust collection cylinders 82 and discharge electrodes 83 are electrically connected to a second nanowave pulse high-voltage power supply. The ends of the multiple reaction cylinders 81 are fitted onto a sealing plate, which is fixed inside the reaction cylinder 81. The discharge electrode 83 is electrically connected to the negative terminal of the second nanowave pulse high-voltage power supply, and the dust collection cylinders 82 are electrically connected to the positive terminal of the second nanowave pulse high-voltage power supply and grounded. The upper end of the reaction cylinder 81 is connected to the outlet end of the electrostatic tower body 41 via a fourth connecting pipe 84, and the lower end of the reaction cylinder 81 is connected to an exhaust fan 51 via a fifth connecting pipe 85. Exhaust gas exiting the electrostatic tower body 41 enters the reaction cylinder 81 through the fourth connecting pipe 84, and then passes through the multiple dust collection cylinders 82. During this passage, the discharge electrode 83 establishes an ionization electric field, and the dust collection cylinders 82 establish an adsorption electric field. When the exhaust gas enters the dust collection cylinder 82, under the action of the ionization electric field, molecules such as nitrogen and oxygen in the air are ionized, forming plasma containing high-energy electrons and free radicals such as O and OH. These active particles have extremely high chemical activity and can undergo a series of complex chemical reactions with VOCs and odor molecules in the exhaust gas. For example, high-energy electrons collide with odor molecules (such as hydrogen sulfide and ammonia), breaking their chemical bonds and decomposing them into smaller molecules; free radicals react with VOCs molecules to undergo oxidation, gradually degrading them into harmless substances such as CO2 and H2O. Through the adsorption electric field, unreacted pollutants are further adsorbed to ensure deodorization. This unit has a VOCs degradation efficiency of ≥90%, an odor removal rate of ≥95%, and does not produce secondary pollution. Example 3

[0051] Based on Example 1, such as Figure 6 As shown, a micro-nano bubble deodorization unit 9 is provided between the electrostatic tower dust removal unit 4 and the discharge unit 5.

[0052] The micro-nano bubble deodorization unit 9 includes a deodorization tank 91 and a micro-nano bubble generator 92. The deodorization tank 91 is a cylindrical sealed structure with a waste gas inlet at the top, connected to the outlet of the electrostatic tower body 41 via a pipe, and a waste gas outlet at the bottom, connected to an exhaust fan 51 via a pipe. The bubble outlet of the micro-nano bubble generator 92 extends into the lower part of the deodorization tank 91. This generator can produce micro-nano bubbles with a diameter of 50-500 nm, and the bubble generation rate can be adjusted by a PLC controller. The large number of active particles (including free radicals and active free oxygen) generated by the nanobubbles promote the reaction with odor molecules in the waste gas, producing a mixture including negative ions, hydroxyl groups, atoms, and free radicals. Although the electron temperature is very high during the process, the heavy particle temperature is very low, and the entire system is at room temperature. The micro-nano bubble technology degrades pollutants by utilizing these high-energy electrons, free radicals, and other active particles to react with pollutants in the waste gas, causing the pollutant molecules to decompose in a very short time and undergo various subsequent reactions to achieve the purpose of pollutant degradation.

[0053] The deodorizing tank 91 is equipped with multiple horizontally arranged porous sieve plates 93 and guide plates 94. The porous sieve plates 93 have fine holes evenly distributed on them. When micro-nano bubbles rise from the bottom of the tank, they pass through the porous sieve plates 93 and are dispersed into finer bubbles, increasing the contact area with the exhaust gas. The guide plates 94 are inclined between adjacent porous sieve plates 93, which can change the flow path of exhaust gas and bubbles, prolong the gas-liquid contact time, and improve the deodorization efficiency. Example 4

[0054] An industrial waste gas purification process includes the following steps: Step 1: Waste heat recovery in stages. The 140-160℃ exhaust gas generated by the stenter is introduced into the upstream heat exchanger 61 of the waste heat recovery unit 6 through the exhaust pipe 64. The exhaust gas flows sequentially through the heat exchange chambers 606 of each downstream heat exchanger 61 and exchanges heat with the fresh air in the heat exchange tube 616. The fresh air enters the downstream heat exchanger 61 from the air inlet pipe 62 and flows upstream through multiple heat exchangers 61. The fresh air is heated to 110-120℃ through multiple stages of heating and then enters the stenter through the return air pipe 63. After heat exchange, the exhaust gas enters the spray main pipe unit 1 through the exhaust pipe 65.

[0055] Step 2: Main pipe spray pretreatment. After the exhaust gas enters the horizontal main pipe, it is sprayed by the first spray head to reduce the temperature to 100±5℃, and also captures large particles of lint, some oil stains and other impurities. At the same time, it cleans the pipes and plays a role in fire safety. The sprayed water is treated and sent to the first cooling tower for cooling, and then circulated to the first spray head by a pump. After removing large particles of lint and oil stains from the exhaust gas, the exhaust gas enters the spray dust removal tower 21.

[0056] Step 3: Vertical spray deep purification. The pre-treated exhaust gas enters the spray dust removal tower 21 through the first connecting pipe 22. The second spray head, arranged in a multi-layered spiral pattern within the spray dust removal tower 21, forms a fine water curtain, further removing large particles of dust and grease with a diameter ≥10μm. During this process, the exhaust gas temperature drops from 100±5℃ to 50-70℃. The sprayed water is treated and sent to the second cooling tower for cooling before being recycled back to the second spray head. The oil-water separation component separates the spray liquid to prevent secondary oil pollution. The exhaust gas then enters the condensation chamber 31 through the second connecting pipe 33.

[0057] Step 4: Multi-pass condensation and dehydration. The exhaust gas passes through multiple linearly arranged condenser plate groups 32 in sequence for stepped cooling. Most of the water vapor in the exhaust gas is condensed and removed, creating a dry environment for subsequent electrostatic dust removal. The condenser plate groups 32 maintain the low-temperature condensation effect through the cooling system.

[0058] Step 5: High-efficiency dust removal using an electrostatic tower. The condensed waste gas enters the electrostatic tower body 41 through the third connecting pipe 43. In the electric field formed by the barbed cathode wire 42 and the anode cylinder, a first nanowave pulse high-voltage power supply (40000-200000V, 60000-80000 times / second) charges fine particles ≤10μm. These charged particles are then adsorbed and removed by the anode cylinder, achieving a dust removal efficiency ≥98%. A millisecond-level flashover control system monitors the electric field status in real time, ensuring safe operation. Energy consumption is only 60%-70% of that of traditional power frequency power supplies.

[0059] Step 6: Discharge. The treated exhaust gas is discharged through chimney 52 under the suction force of exhaust fan 51, meeting emission standards. The control system monitors parameters such as temperature, dust concentration, and VOCs concentration in real time through sensors in each unit, and automatically adjusts the speed of exhaust fan 51, spray volume, power supply, etc., to ensure stable system operation. Example 5

[0060] Based on Example 4, in step 5, after the electrostatic tower for high-efficiency dust removal, plasma deep deodorization is added.

[0061] It also includes step 5-1: plasma deep deodorization. The exhaust gas after being dusted by the electrostatic tower enters the reaction cylinder 81 of the plasma deodorization unit 8. In the electric field formed by the dust collection cylinder 82 and the discharge electrode 83, the second nanowave pulse high voltage power supply ionizes the air through the electric field to generate non-equilibrium plasma, which degrades VOCs and odor molecules into CO2 and H2O. The VOCs degradation efficiency is ≥90% and the odor concentration removal rate is ≥95%. The treated exhaust gas then enters step 6 for discharge. Example 6

[0062] Based on Example 4, in step 5, after the electrostatic tower removes dust efficiently, micro-nano bubble deodorization is added.

[0063] The process also includes step 5-2: micro-nano bubble deodorization. After dust removal, the exhaust gas enters the deodorization tank 91. Micro-nano bubbles with a diameter of 50-500 nm are introduced into the deodorization tank 91 through a micro-nano bubble generator 92. These bubbles possess a large specific surface area and extremely strong surface activity. When the exhaust gas enters the deodorization tank 91, it comes into full contact with the micro-nano bubbles. During their ascent, the micro-nano bubbles rupture, generating an instantaneous high-temperature and high-pressure environment, simultaneously releasing a large number of hydroxyl free radicals. These hydroxyl free radicals have extremely strong oxidizing power and can quickly react with VOCs and odor molecules in the exhaust gas, decomposing them into harmless substances such as CO2 and H2O. The micro-nano bubble technology achieves a VOCs degradation efficiency of ≥92% and an odor removal rate of ≥96%, with no secondary pollution generated during operation. The treated exhaust gas then proceeds to step 6 for emission.

[0064] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications assumed above should also be considered within the scope of protection of the present invention.

Claims

1. An industrial waste gas purification system, comprising a spray main unit (1), a vertical spray unit (2), a multi-pass condensation unit (3), an electrostatic precipitator unit (4), and a discharge unit (5) arranged sequentially, characterized in that: A waste heat recovery unit (6) is provided on the upstream side of the spray main pipe unit (1). The waste heat recovery unit (6) includes multiple heat exchangers (61), an air inlet pipe (62), a return air pipe (63), an exhaust pipe (64), and an outlet pipe (65) arranged in series; the heat outlet (602) of the upstream heat exchanger (61) is connected to the heat inlet (601) of its adjacent downstream heat exchanger (61); the cold outlet (604) of the downstream heat exchanger (61) is connected to the cold inlet (605) of its adjacent upstream heat exchanger (61). 03) Connected; the air inlet pipe (62) is connected to the cold inlet (603) of the downstream heat exchanger (61), and the return air pipe (63) is connected to the cold outlet (604) of the upstream heat exchanger (61); the exhaust pipe (64) is connected to the heat inlet (601) of the sizing machine and the upstream heat exchanger (61), and the exhaust pipe (65) is connected to the heat outlet (602) of the downstream heat exchanger (61) and the spray main pipe unit (1). The electrostatic tower dust removal unit (4) includes an electrostatic tower body (41) and barbed cathode wires (42) and an anode cylinder disposed in the electrostatic tower body (41); the barbed cathode wires (42) and the anode cylinder are electrically connected to the first nanowave pulse high voltage power supply.

2. The industrial waste gas purification system according to claim 1, characterized in that: The heat exchanger (61) includes an outer shell (611) and an inner shell (612), with two annular partitions (613) fixed between the outer shell (611) and the inner shell (612) on the left and right sides; the two annular partitions (613) divide the space between the outer shell (611) and the inner shell (612) into a heat inlet (601), an intermediate cavity (605) and a heat outlet (602). The inner shell (612) is fixed with an inner support plate (614) and an outer partition plate (615) at each end. Multiple arrayed heat exchange tubes (616) are connected between the two inner support plates (614). The two inner support plates (614) and the inner shell (612) form a heat exchange cavity (606). The inner support plate (614), the outer partition plate (615) and the inner shell (612) on the same side form a flow distribution cavity (607). The cold inlet (603) is formed on the outer partition plate (615) on the downstream side, and the cold outlet (604) is formed on the outer partition plate (615) on the upstream side. One of the outer partition plates (615) of two adjacent heat exchangers (61) are attached to each other, and the end faces of the outer shells (611) of two adjacent heat exchangers (61) are attached and sealed and fixedly connected. The upper side wall of the inner shell (612) is formed with an exhaust gas inlet (608) communicating with the heat inlet (601) and the lower side wall of the inner shell (612) is formed with an exhaust gas outlet (609) communicating with the heat outlet (602).

3. The industrial waste gas purification system according to claim 2, characterized in that: The heat exchange tube (616) is a tapered tube, and the diameter of the inlet end of the heat exchange tube (616) is smaller than the diameter of the outlet end of the heat exchange tube (616).

4. The industrial waste gas purification system according to claim 2, characterized in that: The inner shell (612) is provided with a plurality of fire extinguishing branch pipes (701) arranged parallel to the heat exchange tubes (616). Several radial spray holes are formed on the fire extinguishing branch pipes (701). Each row of fire extinguishing branch pipes (701) is connected to a fire extinguishing main pipe (702). The multiple fire extinguishing main pipes (702) pass through the outer protrusion of the inner shell (612) and are connected to the distributor (703). The distributor (703) is connected to a steam pipe (704). The steam pipe (704) is provided with an electromagnetic on / off valve (705). The steam pipe (704) is connected to a steam source. The heat exchange chamber (606) is provided with a second temperature sensor.

5. The industrial waste gas purification system according to claim 4, characterized in that: Each of the exhaust gas inlet (608) and exhaust gas outlet (609) is provided with a Z-shaped baffle (708), and a plurality of nylon pins (706) are sleeved on the Z-shaped baffle (708). The nylon pins (706) are inserted into the inner wall of the inner shell (612). One end of the Z-shaped baffle (708) is inserted into one of the annular partitions (613), and a compression spring (707) is clamped between the Z-shaped baffle (708) and the other annular partition (613).

6. The industrial waste gas purification system according to claim 1, characterized in that: A plasma deodorization unit (8) is provided between the electrostatic tower dust removal unit (4) and the discharge unit (5); The plasma deodorization unit (8) includes a reaction cylinder (81), which is provided with a plurality of vertically arranged dust collection cylinders (82). The dust collection cylinders (82) are provided with discharge electrodes (83). The dust collection cylinders (82) and discharge electrodes (83) are electrically connected to a second nanowave pulse high voltage power supply.

7. The industrial waste gas purification system according to claim 1, characterized in that: A micro-nano bubble deodorization unit (9) is provided between the electrostatic tower dust removal unit (4) and the discharge unit (5). The micro-nano bubble deodorization unit (9) includes a deodorization tank (91) and a micro-nano bubble generator (92). The bubble outlet of the micro-nano bubble generator (92) extends into the lower part of the deodorization tank (91). The deodorization tank (91) is provided with multiple horizontally arranged porous sieve plates (93) and guide plates (94). The guide plates (94) are inclined between adjacent porous sieve plates (93).

8. An industrial waste gas purification process, characterized in that: Includes the following steps: Step 1: Waste heat recovery in stages. The high-temperature exhaust gas generated by the stenter is introduced into the heat exchanger of the waste heat recovery unit through the exhaust pipe. The exhaust gas flows through the heat exchange chambers of multiple heat exchangers in sequence, exchanging heat with the fresh air in the heat exchange tubes. The fresh air enters the downstream heat exchanger from the air inlet pipe, and flows upstream through multiple heat exchangers. After being heated by multiple stages, the fresh air enters the stenter through the return air pipe. The exhaust gas enters the spray main unit through the exhaust pipe after heat exchange. Step 2: Main pipe spray pretreatment. After the exhaust gas enters the horizontal main pipe, it is sprayed by the first spray head to remove large particles of cotton wool and oil stains in the exhaust gas before entering the spray dust removal tower. Step 3: Vertical spray deep purification, which forms a water curtain through the multi-layered spiral distribution of the second spray head to further remove large particles of dust and grease from the exhaust gas; Step 4: Multi-pass condensation and dehydration. The exhaust gas passes through multiple linearly arranged condenser fins in sequence for stepped cooling. The exhaust gas after dehydration by the condenser fins enters the electrostatic tower body. Step 5: High-efficiency dust removal in electrostatic tower. The first nanowave pulse high-voltage power supply generates corona discharge through the barbed cathode wire, which charges the fine particles and adsorbs them by the anode cylinder. Step 6: Discharge. The treated exhaust gas is discharged through a chimney by a blower.

9. The industrial waste gas purification process according to claim 8, characterized in that: It also includes step 5-1: plasma deep deodorization. The exhaust gas after being dusted by the electrostatic tower enters the reaction cylinder of the plasma deodorization unit. In the electric field formed by the dust collection cylinder and the discharge electrode, the second nanowave pulse high voltage power supply ionizes the air through the electric field to generate non-equilibrium plasma. The treated exhaust gas then enters step 6 for discharge.

10. The industrial waste gas purification process according to claim 8, characterized in that: It also includes step 5-2: micro-nano bubble deodorization. The dust-removed waste gas enters the deodorization tank. Micro-nano bubbles with a diameter of 50-500nm are introduced into the deodorization tank through a micro-nano bubble generator. When the waste gas comes into contact with the micro-nano bubbles, the micro-nano bubbles burst to generate a high-temperature and high-pressure environment and hydroxyl free radicals, which react with VOCs and malodor molecules to form an oxidation reaction. The treated waste gas then enters step 6 for emission.

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