Green treatment system and process based on steel structural part coating waste gas

Abstract

The invention discloses a green treatment system and process based on steel structural part coating waste gas, and relates to the technical field of steel structural part coating. The system comprises a multi-stage pretreatment module, a composite adsorption regeneration system, a catalytic oxidation and waste heat recycling module and a data monitoring and operation and maintenance platform. The process comprises the following steps: step 1, multi-stage pretreatment; step 2, gradient adsorption; step 3, microwave regeneration and negative pressure enhanced regeneration, and step 4, intelligent regulation and big data optimization, by adopting a double-layer adsorption structure of zeolite molecular sieve (outer layer) and mesoporous activated carbon (inner layer), differential capture is performed on low-boiling-point and high-boiling-point VOCs: the outer-layer zeolite molecular sieve quickly adsorbs low-boiling-point components, the inner-layer mesoporous activated carbon enriches high-boiling-point components, and the low-boiling-point components and the high-boiling-point components are separated from each other; and meanwhile, the microwave negative pressure regeneration technology is combined, so that high-boiling-point organic matter residues are avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of steel structure painting, and in particular to a green treatment system and process for waste gas from steel structure painting. Background Art

[0002] The spraying process of steel structure products is as follows: the steel structure products after shot blasting and rust removal are sent to a special paint shop and a high-pressure airless spraying process is used. Most large steel structure products need to be shot blasted and sprayed during the production process. The use of paint for spraying will inevitably produce organic waste gas containing TVOC (mainly toluene, xylene and non-methane total hydrocarbons).

[0003] Coating is a systematic project, which includes three basic processes: surface treatment of the coated object before coating, coating process and drying, as well as the design of a reasonable coating system, selection of suitable coatings, determination of good working environment conditions, and important links such as quality, process management and technical economy. The treatment methods of waste gas are different in the operation of different treatment processes. Therefore, it is generally difficult to collect and treat it.

[0004] Patent publication number CN111389161A discloses a process for treating waste gas from steel structure painting, comprising the following steps: exhaust gas from the spray painting workshop enters a bag filter under the power of an exhaust fan, and then enters a pretreatment chamber within a purification chamber through multiple first connecting pipes connected to the bag filter. The present invention connects the exhaust gas from the spray painting workshop (the spraying workshop, the airing workshop, and the drying workshop) to a pretreatment chamber at the bottom of the purification chamber via first connecting pipes, where paint mist is captured. The pretreatment is then achieved by spraying the exhaust gas through an atomizer and performing a secondary water washing operation using a first ball ring packing layer and a second ball ring packing layer. The exhaust gas from the airing workshop and the drying workshop is then directed to the bottom of an adsorption chamber via a second connecting pipe. This allows the exhaust gas from each of the three workshops to undergo different treatment operations, resulting in improved waste gas treatment. However, existing waste gas treatment processes utilize a pretreatment process of "bag filter + two-stage water washing + activated carbon adsorption," treating the exhaust gas solely through water spraying and a single activated carbon adsorption process. For high-boiling-point organic matter with a boiling point greater than 220°C, it is difficult to effectively dissolve it during the water washing process, and the activated carbon has limited adsorption capacity, resulting in the concentration of high-boiling-point VOCs in the outlet exhaust gas easily exceeding the standard. In addition, the UV ultraviolet light beam decomposition stage relies on high-energy ozone, and the cracking efficiency of large-molecule organic matter is insufficient. Moreover, the existing technology uses 120-300°C superheated steam backwashing during activated carbon regeneration, with a steam consumption of 0.5kg / m3 of exhaust gas, and the regeneration time is as long as 30-60 minutes, resulting in high energy consumption. In addition, although the catalytic bed combustion chamber is equipped with a heat exchanger, it is only used to heat the exhaust gas, and the waste heat is not recycled for drying workshops, spray liquid heating, etc., resulting in low energy utilization. At the same time, the system relies on fixed parameters for operation and cannot be dynamically adjusted according to fluctuations in exhaust gas concentration, resulting in serious energy waste during intermittent production. Summary of the Invention

[0005] In view of the deficiencies of the existing technology, the present invention provides a green treatment system and process based on steel structure painting waste gas, which solves the existing problems.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solutions: a green treatment system based on steel structure painting waste gas, comprising:

[0007] Multi-stage pretreatment module: includes a pulse electrostatic precipitator unit, a condensation pretreatment tower, and an ultrasonic atomization spray unit. The pulse electrostatic precipitator removes paint mist particles through the synergistic effect of pulse bags and electrostatic fields. The condensation pretreatment tower recovers high-boiling-point VOCs through spiral condenser tubes. The ultrasonic atomization spray unit atomizes a special absorption liquid into contact with the exhaust gas to remove water-soluble pollutants and some organic components.

[0008] Composite adsorption regeneration system: adopts a double-layer adsorption structure of "zeolite molecular sieve outer layer + mesoporous activated carbon inner layer", combined with a 2450MHz microwave regeneration device and an adsorbent enhanced regeneration unit to achieve high-efficiency adsorption and low-consumption regeneration;

[0009] Catalytic oxidation and waste heat recovery module: Integrates a low-temperature catalytic combustion chamber, an intelligent control system, and a waste heat deep recovery unit to achieve VOCs catalytic oxidation, heat recycling, and dynamic adjustment of system operating parameters;

[0010] Data monitoring and operation and maintenance platform: includes IoT monitoring terminals, fault warning systems, and big data analysis and optimization units, enabling real-time monitoring of full-process parameters, fault warnings, and optimization of system operating parameters.

[0011] Preferably, the electric field strength of the pulse electrostatic precipitator unit is 5-10 kV, and the pulse jet pressure of the bag dust collector is 0.4-0.6 MPa.

[0012] Preferably, in the composite adsorption structure, the silicon-aluminum ratio of the zeolite molecular sieve is 1:2.5-3.0, and the specific surface area of ​​the mesoporous activated carbon is ≥1500m 2 / g.

[0013] Preferably, the intelligent control system adopts an improved fuzzy PID algorithm to dynamically adjust the number of adsorption units in operation. The improved fuzzy PID algorithm formula is:

[0014]

[0015] Where u(t) is the controller output, K p , K i , K d are proportional, integral, and differential coefficients respectively, e(t) is the error, Δu fuzzy It is the fuzzy control increment, which is dynamically determined by the fuzzy rule table based on parameters such as exhaust gas concentration and flow rate.

[0016] Preferably, the big data analysis and optimization unit optimizes the operating parameters of the system using a genetic algorithm, and the fitness function of the genetic algorithm is:

[0017]

[0018] Among them, η is the processing efficiency of the system, E is the energy consumption of the system, and C is the operating cost.

[0019] The present invention also discloses a green treatment process for waste gas from painting steel structures, comprising the following steps:

[0020] Step 1: Multi-stage pretreatment: The exhaust gas is first subjected to pulse electrostatic dust removal to remove particles ≥ 0.1μm, then passed through a condensation tower to recover high-boiling-point VOCs, and finally ultrasonic atomization spraying to remove water-soluble pollutants and some organic components;

[0021] Step 2: Gradient adsorption: After pretreatment, the exhaust gas passes through the zeolite molecular sieve layer and the mesoporous activated carbon layer in sequence to achieve differentiated capture of high and low boiling point VOCs, with the outlet concentration ≤50mg / m 3 ;

[0022] Step 3: Microwave regeneration and negative pressure enhanced regeneration: After adsorption saturation, microwave heating (150-200°C, 15 minutes) is started for desorption. At the same time, the vacuum pump is started to reduce the pressure in the adsorbent bed to 0.1-0.3 MPa. The concentrated exhaust gas is catalytically burned at low temperature (250-300°C) to produce CO2 / H2O, and 80% of the reaction heat is recovered.

[0023] Step 4. Intelligent control and big data optimization: The AI ​​algorithm dynamically adjusts the number of adsorption units according to the exhaust gas concentration and flow rate, and uses big data analysis and optimization units to optimize the system's operating parameters through genetic algorithms to achieve the best match between energy consumption and efficiency.

[0024] Preferably, the absorption liquid spraying amount of the ultrasonic atomization spraying unit is determined according to an improved flow control formula:

[0025] Q spray =k1×Q gas +k2×C pollutant ;

[0026] Among them, Q spray is the absorption liquid spraying amount, Q gas is the exhaust gas flow rate, C pollutant is the pollutant concentration, k1 and k2 are empirical coefficients determined through experiments and data analysis.

[0027] Preferably, the regeneration time and pressure control of the microwave regeneration and negative pressure enhanced regeneration are determined by an improved regeneration control formula:

[0028] t regeneration =a×S adsorbent +b×P negative ;

[0029] Among them, t regeneration is the regeneration time, S adsorbent is the adsorbent saturation, P negative is the negative pressure value, a and b are empirical coefficients determined through experiments and data analysis.

[0030] Preferably, the heating temperature of the absorption liquid in the waste heat deep recycling unit is determined according to an improved temperature control formula:

[0031] T absorbent =k3×Q gas +k4×C pollutant +T0;

[0032] Among them, T absorbent is the absorption liquid heating temperature, Q gas is the exhaust gas flow rate, C pollutant is the pollutant concentration, T0 is the initial temperature, k3 and k4 are empirical coefficients determined through experiments and data analysis.

[0033] Preferably, the frequency of the microwave regeneration is 2450 MHz, the heating rate is 50°C / min, the desorption energy consumption is reduced by more than 40% compared with the steam method, the low-temperature catalytic combustion chamber is filled with modified TiO2 / γ-Al2O3 catalyst, and the ignition temperature is ≤250°C.

[0034] Beneficial effects

[0035] The present invention provides a green treatment system and process for waste gas from steel structure painting. Compared with the existing technology, it has the following advantages:

[0036] 1. This green treatment system and process for waste gas from painting steel structures adopts a double-layer adsorption structure of "zeolite molecular sieve (outer layer) + mesoporous activated carbon (inner layer)" to differentially capture low-boiling point and high-boiling point VOCs: the outer layer of zeolite molecular sieve quickly adsorbs low-boiling point components, and the inner layer of mesoporous activated carbon enriches high-boiling point components, greatly improving the overall adsorption efficiency. At the same time, combined with microwave negative pressure regeneration technology, it avoids the residue of high-boiling point organic matter.

[0037] 2. This green treatment system and process for steel structure painting exhaust gas utilizes an improved fuzzy PID algorithm and genetic algorithm to dynamically adjust the number of adsorption units in operation in real time, reducing energy consumption by 40% under low-concentration conditions. The catalytic oxidation stage utilizes a low-temperature catalyst, combined with a plate heat exchanger to recover 80% of the reaction heat, which is used to preheat the exhaust gas and heat the drying workshop. Furthermore, microwave regeneration consumes less energy than traditional steam methods, creating a closed "adsorption-regeneration-energy cycle" loop. Overall operating costs are significantly lower than existing technologies, improving both economic efficiency and environmental performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 Schematic diagram of the system architecture of the present invention.

[0039] Figure 2 Schematic diagram of the method of the present invention. DETAILED DESCRIPTION

[0040] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0041] See for example Figure 1-2 , the present invention provides the following three technical solutions:

[0042] The first implementation method: a green treatment system for waste gas from painting steel structures, including:

[0043] Multi-stage pretreatment module: includes a pulse electrostatic dust removal unit, a condensation pretreatment tower and an ultrasonic atomization spray unit. The pulse electrostatic dust removal unit removes paint mist particles through the synergistic effect of pulse bags and electrostatic fields. The condensation pretreatment tower recovers high-boiling-point VOCs through spiral condenser tubes. The ultrasonic atomization spray unit atomizes special absorption liquid into contact with the exhaust gas to remove water-soluble pollutants and some organic components.

[0044] Pulse electrostatic precipitator unit:

[0045] The integrated pulse bag dust collector and electrostatic dust collector form a two-stage dust removal system. The pulse bag dust collector removes paint mist particles larger than 5μm through 0.4-0.6MPa pulse airflow (cycle 5min), with a dust removal efficiency of ≥99%. The electrostatic dust collector at the rear end applies an electric field strength of 5-10kV, using corona discharge to charge fine particles of 0.1-5μm, which are adsorbed on the surface of the plate. The final dust content in the exhaust gas is ≤1mg / m 3 , which solves the problem of low efficiency of traditional bag dust removal in treating submicron particles.

[0046] Condensation pretreatment tower:

[0047] The built-in spiral condenser (cooling medium temperature 5-10℃) cools the exhaust gas to 20-30℃ after entering, and high-boiling-point VOCs (such as xylene and styrene) are condensed into liquid and collected into the liquid storage tank through the diversion trough, reducing the load of subsequent adsorption units and reducing the amount of activated carbon by 30%.

[0048] Ultrasonic atomization spray unit:

[0049] An ultrasonic atomizing nozzle (frequency 1-3MHz) is added to atomize the absorption liquid containing surfactant into 5-20μm droplets, which come into reverse contact with the exhaust gas to effectively remove water-soluble pollutants (such as ethanol, acetone) and some hydrophilic organic components. The absorption liquid spray volume is calculated by the formula Q spray =k1×Q gas +k2×C pollutantDynamic adjustment (k1 and k2 are calibrated by experiments) ensures maximum gas-liquid contact efficiency.

[0050] Composite adsorption regeneration system: adopts a double-layer adsorption structure of "zeolite molecular sieve outer layer + mesoporous activated carbon inner layer", combined with a 2450MHz microwave regeneration device and an adsorbent enhanced regeneration unit to achieve high-efficiency adsorption and low-consumption regeneration.

[0051] Gradient adsorption unit:

[0052] Adopting the double-layer structure of "zeolite molecular sieve (outer layer) + mesoporous activated carbon (inner layer)":

[0053] Outer layer zeolite molecular sieve (Si-Al ratio 1:2.8, pore size ) preferentially adsorbs low-boiling-point VOCs (such as toluene, adsorption capacity 18%), with a space velocity of 10,000 h -1 ;

[0054] Inner layer mesoporous activated carbon (specific surface area ≥1500m 2 / g, pore size 2-50nm) to enrich high boiling point components (such as styrene, adsorption capacity 25%), space velocity 8000h -1 The double-layer synergistic effect increases the overall adsorption efficiency to more than 98%, and the outlet VOCs concentration is ≤50mg / m 3 .

[0055] Microwave regeneration device:

[0056] Using 2450MHz microwave heating technology and a heating rate of 50°C / min, rapid desorption occurs at 150-200°C (desorption time is 50% shorter than with steam). Combined with negative pressure regeneration technology (0.1-0.3MPa), a vacuum pump lowers the adsorbent bed pressure, promoting adsorbate desorption. Regeneration energy consumption is reduced by 40% compared to traditional processes, and adsorbent life is extended by 20%.

[0057] Catalytic oxidation and waste heat recovery module: Integrates a low-temperature catalytic combustion chamber, an intelligent control system, and a waste heat deep recovery unit to achieve VOCs catalytic oxidation, heat recycling, and dynamic adjustment of system operating parameters.

[0058] Low temperature catalytic combustion chamber:

[0059] The modified TiO2 / γ-Al2O3 catalyst (with 0.5% Pt additive) is loaded, and the ignition temperature is reduced to 250℃ (50℃ lower than the traditional catalyst), which is effective for concentrated exhaust gas (VOCs concentration ≥ 5000mg / m 3 ) catalytic oxidation, the reaction formula is:

[0060]

[0061] The purification efficiency is ≥99%, and 80% of the reaction heat is recovered through the plate heat exchanger and used to preheat the exhaust gas to 80°C or heat the absorption liquid, reducing the electric heating energy consumption by 60%.

[0062] Intelligent control system:

[0063] The integrated PLC controller and improved fuzzy PID algorithm collect 12 parameters such as exhaust gas flow, concentration, temperature, etc. in real time. The control formula is:

[0064]

[0065] Where u(t) is the controller output, K p , K i , K d are proportional, integral, and differential coefficients respectively, e(t) is the error, Δu fuzzy It is a fuzzy control increment, which dynamically adjusts the number of adsorption units in operation (1-4 groups of intelligent switching) according to the fluctuation of exhaust gas concentration to achieve the optimal match between energy consumption and efficiency.

[0066] Data monitoring and operation and maintenance platform: includes IoT monitoring terminals, fault warning systems, and big data analysis and optimization units, enabling real-time monitoring of full-process parameters, fault warnings, and optimization of system operating parameters.

[0067] IoT monitoring terminal:

[0068] Laser dust sensors and PID gas detectors are deployed to monitor dust removal efficiency, adsorbent saturation, and catalytic bed temperature in real time, and the data is uploaded to the cloud platform via the 5G network.

[0069] Big Data Analysis and Optimization Unit:

[0070] Genetic algorithm is used to optimize system parameters, and the fitness function is: (η is the system's processing efficiency, E is the system's energy consumption, and C is the operating cost). By iteratively calculating and generating the optimal control strategy (such as adsorption unit switching time and catalyst bed temperature setting), the overall system performance was improved by 15%.

[0071] The second implementation method: a green treatment method for waste gas from painting steel structures, comprising the following steps:

[0072] Step 1: Multi-stage pretreatment: The exhaust gas is first subjected to pulse electrostatic dust removal to remove particles ≥ 0.1μm, then passed through a condensation tower to recover high-boiling point VOCs, and finally ultrasonic atomization spraying to remove water-soluble pollutants and some organic components.

[0073] Pulse electrostatic dust removal: The spraying exhaust gas first enters the pulse bag dust collector, where large particles of paint mist are removed through high-frequency pulse airflow, and then enters the electrostatic dust removal area, where the electric field force is used to capture fine dust, ensuring that the cleanliness of the exhaust gas after dust removal meets the requirements of subsequent treatment.

[0074] Condensation recovery: The air-dried / dried exhaust gas (40-60°C) enters the condensation tower and contacts with low-temperature cooling water in reverse. The high-boiling-point VOCs are condensed into droplets, which can be collected and recycled for reuse, thus reducing the subsequent adsorption load.

[0075] Ultrasonic atomization spray: The waste gas after dust removal and condensation enters the spray unit and is fully mixed with the atomized absorption liquid to remove water-soluble pollutants and some organic components. The absorption liquid temperature is heated to 30-40°C through the waste heat recovery system to improve the absorption efficiency.

[0076] Step 2: Gradient adsorption: After pretreatment, the exhaust gas passes through the zeolite molecular sieve layer and the mesoporous activated carbon layer in sequence to achieve differentiated capture of high and low boiling point VOCs, with the outlet concentration ≤50mg / m 3 .

[0077] Composite adsorption treatment: After pretreatment, the exhaust gas (≤30℃) passes through the zeolite molecular sieve layer and the mesoporous activated carbon layer in sequence. The low-boiling point components are quickly captured by the outer layer, and the high-boiling point components are enriched in the inner layer, achieving differentiated purification. The outlet concentration is better than the national standard requirements.

[0078] Microwave negative pressure regeneration: When the adsorbent saturation is greater than 80%, microwave heating and negative pressure synergistic regeneration are started, desorption is completed within 15 minutes, and the concentrated exhaust gas is sent to the catalytic combustion chamber. The regeneration process has low energy consumption and no secondary pollution.

[0079] Step 3: Microwave regeneration and negative pressure enhanced regeneration: After adsorption saturation, microwave heating (150-200°C, 15 minutes) is started for desorption. At the same time, the vacuum pump is started to reduce the pressure in the adsorbent bed to 0.1-0.3 MPa. The concentrated exhaust gas is catalytically burned at low temperature (250-300°C) to generate CO2 / H2O, and 80% of the reaction heat is recovered.

[0080] Low-temperature catalytic combustion: concentrated exhaust gas is catalytically oxidized at 250-300℃ to produce CO2 and H2O. The reaction heat is recovered through a heat exchanger, part of which is used to preheat the incoming exhaust gas, and the other part is used to dry the workshop or heat the absorption liquid, realizing multi-level energy utilization.

[0081] Emission and reuse: The purified gas is discharged through a 15m chimney, and part of the clean hot gas is returned to the drying workshop, replacing 20% ​​of the heating energy consumption.

[0082] Step 4. Intelligent control and big data optimization: The AI ​​algorithm dynamically adjusts the number of adsorption units according to the exhaust gas concentration and flow rate, and uses big data analysis and optimization units to optimize the system's operating parameters through genetic algorithms to achieve the best match between energy consumption and efficiency.

[0083] Dynamic load matching: The AI ​​algorithm analyzes the exhaust gas flow and concentration of the spraying, air-drying and drying processes in real time, and automatically adjusts the number of adsorption units in operation. For example, during the peak spraying period, four groups of units are started, and during the air-drying period, only two groups are switched to avoid energy waste.

[0084] Full-process monitoring and optimization: The cloud platform displays the parameters of each module in real time. When the efficiency of the adsorption unit drops by more than 10%, the standby unit switching and regeneration process is automatically triggered. The operating parameters are continuously optimized through genetic algorithms to ensure the long-term stable and efficient operation of the system.

[0085] The third implementation method: Example, a heavy machinery steel structure coating line

[0086] System parameters

[0087] Preprocessing unit:

[0088] The pulse electrostatic dust removal efficiency is 99.3%, the condensation tower recovers 5.2 kg / h of xylene (recovery rate 85%), and the ultrasonic atomization spray removes water-soluble pollutants with an efficiency of 88%.

[0089] Adsorption regeneration unit:

[0090] Four groups of adsorption units operate in rotation, with microwave regeneration time of 15 minutes per time, negative pressure maintained at 0.2 MPa, and regeneration energy consumption of 12 kWh per time, saving 18 kWh per time compared with traditional processes.

[0091] Catalytic oxidation unit:

[0092] The catalyst bed inlet temperature is 255℃ and the outlet VOCs concentration is 12mg / m 3 The heat exchanger recovers heat to preheat the exhaust gas to 75°C, saving 30kW of electric heating power, and at the same time heats the absorption liquid to 35°C.

[0093] Treatment Effect

[0094] Emission index: particulate matter 0.8mg / m 3 , VOCs15mg / m 3 , which is better than the secondary standard of the "Integrated Emission Standard of Air Pollutants" (GB16297-1996).

[0095] Energy consumption and cost: Electricity consumption is reduced by 30% and natural gas consumption is reduced by 38% compared with existing technologies, saving more than RMB 600,000 in annual operating costs.

[0096] Maintenance and control

[0097] When the cloud platform detects that the saturation of a group of activated carbon reaches 85% (yellow warning), it automatically switches to the backup unit and starts the regeneration program. The entire process does not require human intervention and the response time is 25 seconds.

[0098] After optimization through genetic algorithm, the switching time of the adsorption unit was shortened from the traditional 5 minutes to 2 minutes, and the overall efficiency of the system was improved by 18%.

[0099] At the same time, the contents not described in detail in this specification belong to the existing technology known to those skilled in the art, and the model parameters of each electrical appliance are not specifically limited, and conventional equipment can be used.

[0100] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus.

[0101] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. The green treatment system based on steel structure painting waste gas is characterized by: include: Multi-stage pretreatment module: includes a pulse electrostatic precipitator unit, a condensation pretreatment tower, and an ultrasonic atomization spray unit. The pulse electrostatic precipitator removes paint mist particles through the synergistic effect of pulse bags and electrostatic fields. The condensation pretreatment tower recovers high-boiling-point VOCs through spiral condenser tubes. The ultrasonic atomization spray unit atomizes a special absorption liquid into contact with the exhaust gas to remove water-soluble pollutants and some organic components. Composite adsorption regeneration system: adopts a double-layer adsorption structure of "zeolite molecular sieve outer layer + mesoporous activated carbon inner layer", combined with a 2450MHz microwave regeneration device and an adsorbent enhanced regeneration unit to achieve high-efficiency adsorption and low-consumption regeneration; Catalytic oxidation and waste heat recovery module: Integrates a low-temperature catalytic combustion chamber, an intelligent control system, and a waste heat deep recovery unit to achieve VOCs catalytic oxidation, heat recycling, and dynamic adjustment of system operating parameters; Data monitoring and operation and maintenance platform: includes IoT monitoring terminals, fault warning systems, and big data analysis and optimization units, enabling real-time monitoring of full-process parameters, fault warnings, and optimization of system operating parameters.

2. The green treatment system for steel structure painting waste gas according to claim 1 is characterized by: The electric field strength of the pulse electrostatic precipitator unit is 5-10 kV, and the pulse jet pressure of the bag dust collector is 0.4-0.6 MPa.

3. The green treatment system for steel structure painting waste gas according to claim 1 is characterized by: In the composite adsorption structure, the silicon-aluminum ratio of the zeolite molecular sieve is 1:2.5-3.0, and the specific surface area of ​​the mesoporous activated carbon is ≥1500m 2 / g.

4. The green treatment system for steel structure painting waste gas according to claim 1 is characterized by: The intelligent control system adopts an improved fuzzy PID algorithm to dynamically adjust the number of adsorption units in operation. The improved fuzzy PID algorithm formula is: Where u(t) is the controller output, K p , K i , K d are proportional, integral, and differential coefficients respectively, e(t) is the error, Δu fuzzy It is the fuzzy control increment, which is dynamically determined by the fuzzy rule table according to the parameters of exhaust gas concentration and flow rate.

5. The green treatment system for steel structure painting waste gas according to claim 1 is characterized by: The big data analysis and optimization unit uses a genetic algorithm to optimize the operating parameters of the system. The fitness function of the genetic algorithm is: Among them, η is the processing efficiency of the system, E is the energy consumption of the system, and C is the operating cost.

6. A green treatment process for waste gas from painting of steel structures, based on a green treatment system for waste gas from painting of steel structures according to any one of claims 1 to 5, characterized in that: The following steps are involved: Step 1: Multi-stage pretreatment: The exhaust gas is first subjected to pulse electrostatic dust removal to remove particles ≥ 0.1μm, then passed through a condensation tower to recover high-boiling-point VOCs, and finally ultrasonic atomization spraying to remove water-soluble pollutants and some organic components; Step 2: Gradient adsorption: After pretreatment, the exhaust gas passes through the zeolite molecular sieve layer and the mesoporous activated carbon layer in sequence to achieve differentiated capture of high and low boiling point VOCs; Step 3: Microwave regeneration and negative pressure enhanced regeneration: After adsorption saturation, microwave heating desorption is started, and the vacuum pump is started to reduce the pressure in the adsorbent bed to 0.1-0.3MPa. The concentrated exhaust gas is catalytically burned at low temperature to produce CO2 / H2O, and 80% of the reaction heat is recovered. Step 4. Intelligent control and big data optimization: The AI ​​algorithm dynamically adjusts the number of adsorption units according to the exhaust gas concentration and flow rate, and uses big data analysis and optimization units to optimize the system's operating parameters through genetic algorithms to achieve the best match between energy consumption and efficiency.

7. The green treatment process for waste gas from painting of steel structures according to claim 6 is characterized by: The absorption liquid spraying amount of the ultrasonic atomization spraying unit is determined according to the improved flow control formula: Q spray =k1×Q gas +k2×C pollutant ; Among them, Q spray is the absorption liquid spraying amount, Q gas is the exhaust gas flow rate, C pollutant is the pollutant concentration, k1 and k2 are empirical coefficients determined through experiments and data analysis.

8. The green treatment process for steel structure painting waste gas according to claim 6 is characterized by: The regeneration time and pressure control of the microwave regeneration and negative pressure enhanced regeneration are determined by the improved regeneration control formula: t regeneraiton =a×S adsorbent +b×P negative ; Among them, t regeneration is the regeneration time, S adsorbent is the adsorbent saturation, P negative is the negative pressure value, a and b are empirical coefficients determined through experiments and data analysis.

9. The green treatment process for waste gas from steel structure painting according to claim 6 is characterized by: The heating temperature of the absorption liquid in the waste heat deep recycling unit is determined according to the improved temperature control formula: T absorbent =k3×Q gas +k4×C pollutant +T0; Among them, T absorbent is the absorption liquid heating temperature, Q gas is the exhaust gas flow rate, C pollutant is the pollutant concentration, T0 is the initial temperature, k3 and k4 are empirical coefficients determined through experiments and data analysis.

10. The green treatment process for steel structure painting waste gas according to claim 6, characterized in that: The frequency of the microwave regeneration is 2450 MHz, the heating rate is 50°C / min, and the desorption energy consumption is reduced by more than 40% compared with the steam method. The low-temperature catalytic combustion chamber is filled with a modified TiO2 / γ-Al2O3 catalyst, and the ignition temperature is ≤250°C.

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