Intelligently-controlled color coating production line VOC emission monitoring and treatment system

Abstract

The invention discloses color coating industry VOC (Volatile Organic Compound) purification equipment based on a novel catalysis technology, which comprises a waste gas collection device, a pretreatment device and a novel catalytic reaction device, the waste gas collection device comprises a sealing cover and an induced draft fan, the induced draft fan is connected with the sealing cover, and the pretreatment device comprises a condenser connected with the induced draft fan; the novel catalytic reaction device comprises a reaction exhaust chamber connected with a condenser, a plurality of groups of carrier frames are connected in the reaction exhaust chamber, the carrier frames are coated with novel catalysts, the novel catalysts comprise carriers and active components, the carriers are composite metal oxides, and the active components comprise main active components and auxiliary active components. The method has the beneficial effects that the purification process is efficient; the catalyst has high performance; and the equipment structure is reasonable.

Description

Technical Field

[0001] The present invention relates to the technical field of environmental protection equipment for color coating production lines, and particularly relates to an intelligent control system for monitoring and treating VOC emissions in color coating production lines. Background Art

[0002] In modern industrial production, as a key link in metal surface treatment, color coating production lines are widely used in many fields such as construction, household appliances, and automobiles. With the rapid development of these industries, the scale and output of color coating production lines are constantly expanding. However, the problem of volatile organic compound (VOC) exhaust gas emissions generated during their operation is becoming increasingly prominent.

[0003] VOCs are a class of organic compounds that are volatile at normal temperatures. A large amount of VOCs will be released from raw materials such as paints and thinners used in the color coating production process. If these exhaust gases are directly discharged into the atmosphere without effective treatment, they will cause serious pollution to the environment in many aspects. On the one hand, VOCs are important precursors for the formation of photochemical smog. Under sunlight, VOCs and nitrogen oxides undergo a series of complex photochemical reactions to produce secondary pollutants such as ozone and peroxyacetyl nitrate, seriously affecting air quality, leading to frequent occurrence of smoggy weather, endangering the ecological balance, and threatening the survival and reproduction of animals and plants. On the other hand, many VOCs are toxic and carcinogenic. Long-term exposure to an environment containing VOCs will pose a great threat to human health. For example, it can damage the respiratory system, causing diseases such as cough, asthma, and difficulty in breathing; it can affect the nervous system, resulting in symptoms such as dizziness, fatigue, and memory loss, and may even induce cancer, seriously endangering people's lives.

[0004] At present, there are many deficiencies in the existing VOC emission treatment technologies for color coating production lines. In terms of waste gas collection, some traditional treatment systems only use simple air collection hoods, with limited collection ranges and being greatly affected by the air flow in the workshop. They cannot comprehensively and effectively collect the waste gas generated during the production process, resulting in a large amount of waste gas escaping into the workshop environment, which not only pollutes the workshop air but also increases the difficulty of subsequent treatment. In the waste gas treatment link, some technologies such as the adsorption method are prone to adsorption saturation problems, requiring frequent replacement of adsorbents, with high costs and gradually declining treatment effects; while the combustion method, although having a high treatment efficiency, has high energy consumption, is prone to secondary pollution, and has poor treatment effects on low-concentration VOC waste gas, making it difficult to meet the increasingly strict environmental protection emission standards. At the same time, most of the existing monitoring systems use single-point monitoring or a small number of sensors for monitoring, with low monitoring accuracy and being unable to comprehensively reflect the distribution of VOC concentrations in the waste gas; and the data transmission and processing speeds are slow, with poor real-time performance, unable to accurately and timely feedback the changes in VOC concentrations in the waste gas, and it is difficult to provide effective data support for the operation of the treatment system. In addition, most treatment systems lack intelligent control, rely on manual experience for operation and adjustment, and are difficult to automatically adjust treatment parameters according to the actual flow rate, concentration, composition, etc. of the waste gas, resulting in energy waste and increased treatment costs, and being unable to meet the requirements of high efficiency and environmental protection in modern industrial production.

[0005] In summary, it is of great practical significance and extremely urgent to develop an efficient, intelligent, and environmentally friendly VOC emission monitoring and treatment system for color coating production lines. It can not only effectively solve the environmental protection problems faced by the current color coating industry, reduce the harm to the environment and human health, but also improve production efficiency, reduce production costs, and promote the sustainable development of the color coating industry. Summary of the Invention

[0006] To solve the above problems, especially aiming at the deficiencies of the existing technologies, the present invention provides an intelligent-controlled VOC emission monitoring and treatment system for color coating production lines that can solve the above problems.

[0007] To achieve the above object, the present invention adopts the following technical means:

[0008] An intelligent-controlled VOC emission monitoring and treatment system for color coating production lines, comprising a waste gas collection device, a pretreatment device, a catalytic reaction device, a monitoring device, a diversion device, a combustion device, and a control device;

[0009] The waste gas collection device includes a sealing cover and an induced draft fan. The sealing cover is arranged at the waste gas discharge port of the color coating equipment, and the induced draft fan is connected to the sealing cover to extract the waste gas from inside the sealing cover and transport it to the pretreatment device;

[0010] The pre-treatment device includes a condenser connected to an induced draft fan. The condenser cools the waste gas through a cooling medium, causing some high-boiling VOCs to condense into a liquid state and be discharged and collected through a drain pipe.

[0011] The catalytic reaction device includes a reaction exhaust chamber connected to the condenser. The reaction exhaust chamber is filled with a novel catalyst, and the waste gas is decomposed by the built-in novel catalyst in the reaction exhaust chamber.

[0012] The monitoring device includes a monitoring ventilation pipe connected to the exhaust port of the reaction exhaust chamber. Multiple groups of evenly distributed VOC concentration sensors are connected inside the monitoring ventilation pipe.

[0013] The shunt device includes a tee shunt pipe connected to the monitoring ventilation pipe. One exhaust port of the tee shunt pipe is connected to an exhaust pipe through an exhaust valve.

[0014] The combustion device includes a combustion chamber connected to the other exhaust port of the tee shunt pipe through a gas return valve.

[0015] The control device includes a control cabinet. A cabinet door is hinged at the opening of the control cabinet. A power module and a PLC controller are connected inside the control cabinet. A touch screen is inlaid and connected to the cabinet door. The induced draft fan, condenser, reaction exhaust chamber, exhaust valve, gas return valve, combustion chamber, PLC controller, and touch screen are respectively connected to the power module. The induced draft fan, condenser, reaction exhaust chamber, VOC concentration sensor, exhaust valve, gas return valve, combustion chamber, and touch screen are respectively connected to the PLC controller.

[0016] The novel catalyst includes a carrier and an active component supported on the carrier.

[0017] The carrier is an organic-inorganic hybrid material, formed by combining polyaniline and mesoporous silica through an in-situ polymerization method.

[0018] The active component includes a main active component and a co-active component. The main active component is alloy nanoparticles of palladium, ruthenium, and rhodium, and the particle size of the alloy nanoparticles is controlled between 5 and 10 nanometers. The co-active component includes phosphomolybdic acid and transition metal sulfides. The transition metal sulfides include molybdenum disulfide and tungsten disulfide.

[0019] A further solution of the present invention is that a filter screen is installed at the air inlet of the sealing cover.

[0020] A further solution of the present invention is that the reaction exhaust chamber is connected to a heat exchanger.

[0021] A further solution of the present invention is that the monitoring ventilation pipe is connected to a support frame.

[0022] A further solution of the present invention is that support rods are respectively connected to the corners at the bottom of the control cabinet.

[0023] A further solution of the present invention is that in the carrier, the mass ratio of polyaniline to mesoporous silica is (1:3)-(3:1).

[0024] A further solution of the present invention is that in the main active component, in the alloy nanoparticles of palladium, ruthenium, and rhodium, the atomic ratio of palladium, ruthenium, and rhodium is (3:2:1)-(5:3:2).

[0025] A further solution of the present invention is that in the co-active component, the mass ratio of phosphomolybdic acid to transition metal sulfide is (1:2)-(2:1).

[0026] A further solution of the present invention is that the method for preparing the novel catalyst includes the following steps:

[0027] Preparation of the carrier:

[0028] Dissolve tetraethyl orthosilicate in a mixed solution of ethanol and deionized water, add the template agent cetyltrimethylammonium bromide, and carry out hydrolysis and polycondensation reactions under acidic conditions to form a mesoporous silica precursor;

[0029] Add aniline monomer and initiator ammonium persulfate to the mesoporous silica precursor solution, and through in-situ polymerization reaction, make polyaniline grow in the pores and on the surface of mesoporous silica to form a polyaniline-mesoporous silica hybrid material;

[0030] Remove the template agent by high-temperature calcination to obtain an organic-inorganic hybrid carrier with a regular pore structure;

[0031] Loading of the active component:

[0032] Loading of the main active component: Dissolve metal salts of palladium, ruthenium, and rhodium in an appropriate solvent, add reducing agent sodium borohydride and protective agent polyvinylpyrrolidone, and under stirring conditions, reduce metal ions to alloy nanoparticles and load them onto the organic-inorganic hybrid carrier;

[0033] Loading of the co-active component: Dissolve phosphomolybdic acid and the precursor of transition metal sulfide in water to form a mixed solution; immerse the carrier loaded with the main active component in this mixed solution, and by impregnation method, load the co-active component precursor onto the carrier; then, through hydrothermal reaction, convert the precursor into phosphomolybdic acid and transition metal sulfide to achieve stable loading of the co-active component.

[0034] A further solution of the present invention is that in the preparation step of the carrier, the temperature of the hydrolysis and polycondensation reaction is 50-70°C, and the reaction time is 4-8 hours; the temperature of the high-temperature calcination is 450-550°C, and the calcination time is 3-5 hours;

[0035] In the main active component loading step, the solvent for dissolving the metal salt is ethylene glycol, the stirring conditions are a rotation speed of 500 - 1000 revolutions per minute, the reaction temperature is 0 - 5 °C, and the reaction time is 1 - 2 hours;

[0036] In the co - active component loading step, the impregnation time is 10 - 14 hours, the temperature of the hydrothermal reaction is 160 - 200 °C, and the reaction time is 10 - 14 hours.

[0037] Advantages of the present invention:

[0038] 1. The present invention can efficiently collect waste gas: The system is tightly arranged at the waste gas discharge port of the color coating equipment through a sealing cover. With the powerful air extraction ability of the induced draft fan, it can collect the waste gas generated during the production process to the greatest extent, effectively avoiding the escape of waste gas into the workshop environment. The collection efficiency is greatly improved compared with the traditional simple air collection hood, ensuring the air quality in the workshop and providing a sufficient and stable waste gas source for subsequent treatment.

[0039] 2. The present invention can deeply pre - treat: The condenser in the pre - treatment device cools the waste gas using a cooling medium, causing some high - boiling - point VOCs to condense into a liquid state and be discharged and collected. This process not only reduces the content of VOCs in the waste gas, alleviates the treatment burden of the subsequent catalytic reaction device, but also recovers some valuable substances, reducing production costs. At the same time, the condensation process also has a certain effect on removing impurities such as water vapor in the waste gas, protecting the subsequent equipment and extending the service life of the equipment.

[0040] 3. The present invention can efficiently catalyze and decompose: The new catalyst filled in the catalytic reaction device has a unique structure and composition. The organic - inorganic hybrid material carrier provides a good support and dispersion environment for the active components. The alloy nanoparticles of the main active components palladium, ruthenium, and rhodium have a particle size controlled between 5 - 10 nanometers, with extremely high catalytic activity, and can quickly and effectively decompose VOCs in the waste gas. The synergistic effect of the co - active components phosphomolybdic acid and transition metal sulfides further enhances the activity and stability of the catalyst, making the waste gas decomposition more complete, improving the treatment effect, and ensuring that the discharged waste gas meets strict environmental protection standards.

[0041] 4. The present invention can accurately monitor in real - time: The monitoring ventilation pipe in the monitoring device is connected to the reaction exhaust chamber, and there are multiple groups of evenly distributed VOC concentration sensors inside. These sensors can monitor the VOC concentration in the waste gas in real - time and comprehensively, accurately capturing the changes in the waste gas concentration. Compared with traditional single - point monitoring or monitoring with a small number of sensors, the monitoring accuracy is greatly improved. At the same time, the sensors transmit the monitoring data to the PLC controller in a timely manner, providing accurate data basis for the intelligent control of the system.

[0042] 5. The present invention can flexibly treat waste gas: the shunt device and the combustion device cooperate with each other, and the system can automatically make a judgment according to the VOC concentration data fed back by the monitoring device. When the VOC concentration in the waste gas is lower than the emission standard, the exhaust valve opens, and the waste gas is directly discharged through the exhaust pipe; when the concentration is higher than the emission standard, the return air valve opens, and the waste gas enters the combustion chamber for combustion treatment, ensuring that the discharged waste gas always meets the standard and avoiding the pollution to the environment caused by excessive emission.

[0043] 6. The present invention can intelligently control and manage: the control device takes the PLC controller as the core and realizes the intelligent control of the system in combination with the touch screen. The operator can conveniently set system parameters, view the running state and monitoring data through the touch screen. The PLC controller automatically adjusts the running parameters of devices such as the induced draft fan, condenser, reaction exhaust chamber, etc. according to the information of waste gas flow rate, concentration, composition, etc. fed back by the monitoring device, realizing the automatic operation of the system. This intelligent control not only improves the treatment efficiency, but also can optimize the energy distribution according to the actual situation, reducing the energy consumption and operation cost, enabling the system to better meet the requirements of high efficiency and environmental protection in modern industrial production and promoting the sustainable development of the color coating industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 is a structural schematic diagram of the present invention;

[0045] Figure 2 is a cross-sectional view of the monitoring ventilation pipe of the present invention;

[0046] Figure 3 is a structural schematic diagram of the control device of the present invention;

[0047] Reference numerals:

[0048] Sealing cover 1, filter screen 2, induced draft fan 3, condenser 4, reaction exhaust chamber 5, heat exchanger 6, monitoring ventilation pipe 7, VOC concentration sensor 8, support frame 9, three-way shunt pipe 10, exhaust valve 11, exhaust pipe 12, return air valve 13, combustion chamber 14, control cabinet 15, power supply module 16, PLC controller 17, cabinet door 18, touch screen 19, support rod 20. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0049] The technical solutions of the present invention will be clearly and completely described below in conjunction with the drawings. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the protection scope of the present invention.

[0050] Embodiment 1

[0051] AsFigures 1-3 As shown in the figure, an intelligent control VOC emission monitoring and treatment system for a color coating production line includes an exhaust gas collection device, a pretreatment device, a catalytic reaction device, a monitoring device, a shunt device, a combustion device, and a control device;

[0052] The exhaust gas collection device includes a sealing cover 1 and an induced draft fan 3. The sealing cover 1 is arranged at the exhaust gas discharge port of the color coating equipment. The induced draft fan 3 is connected to the sealing cover 1 to extract the exhaust gas from the inside of the sealing cover 1 and transport it to the pretreatment device;

[0053] The pretreatment device includes a condenser 4 connected to the induced draft fan 3. The condenser 4 cools the exhaust gas through a cooling medium to condense some high-boiling VOCs into a liquid state and discharge and collect them through a drain pipe;

[0054] The catalytic reaction device includes a reaction exhaust chamber 5 connected to the condenser 4. The reaction exhaust chamber 5 is filled with a new type of catalyst, and the reaction exhaust chamber 5 decomposes the exhaust gas through the built-in new type of catalyst;

[0055] The monitoring device includes a monitoring ventilation pipe 7 connected to the exhaust port of the reaction exhaust chamber 5. A plurality of groups of uniformly distributed VOC concentration sensors 8 are connected inside the monitoring ventilation pipe 7;

[0056] The shunt device includes a three-way shunt pipe 10 connected to the monitoring ventilation pipe 7. One exhaust port of the three-way shunt pipe 10 is connected to an exhaust pipe 12 through an exhaust valve 11;

[0057] The combustion device includes a combustion chamber 14 connected to the other exhaust port of the three-way shunt pipe 10 through a return air valve 13;

[0058] The control device includes a control cabinet 15. A cabinet door 18 is hinged at the opening of the control cabinet 15. A power module 16 and a PLC controller 17 are connected inside the control cabinet 15. A touch screen 19 is inlaid and connected to the cabinet door 18. The induced draft fan 3, the condenser 4, the reaction exhaust chamber 5, the exhaust valve 11, the return air valve 13, the combustion chamber 14, the PLC controller 17, and the touch screen 19 are respectively connected to the power module 16. The induced draft fan 3, the condenser 4, the reaction exhaust chamber 5, the VOC concentration sensor 8, the exhaust valve 11, the return air valve 13, the combustion chamber 14, and the touch screen 19 are respectively connected to the PLC controller 17.

[0059] A filter screen 2 is installed at the air inlet of the sealing cover 1.

[0060] The advantages of the above settings are:

[0061] Filter impurities and protect equipment: During the color coating production process, the exhaust gas may carry solid impurities such as dust and debris. The filter net can intercept these impurities and prevent them from entering equipment such as the induced draft fan 3, condenser 4, and reaction exhaust chamber 5. For example, if the blades of the induced draft fan 3 are worn by impurities, the air extraction efficiency and stability will be affected; if the internal pipes of the condenser 4 are blocked by impurities, the heat exchange efficiency will be reduced, affecting the VOC condensation effect. The filter net 2 can effectively prevent these situations from occurring and extend the service life of the equipment.

[0062] Improve the exhaust gas treatment efficiency: When impurities enter the catalytic reaction device, they will cover the surface of the catalyst, occupy the active sites, reduce the activity of the catalyst, and affect the VOC decomposition effect. The filter net 2 filters impurities in advance, ensuring that the exhaust gas entering the reaction device is pure, allowing the catalyst to fully play its role, improving the exhaust gas treatment efficiency, and ensuring that the finally discharged exhaust gas meets environmental protection standards.

[0063] Reduce maintenance costs: Without the filter net 2, after impurities accumulate inside the equipment, frequent cleaning, maintenance, and even replacement of parts are required, which will consume a large amount of manpower, material resources, and time costs. After installing the filter net, the equipment is less affected by impurities, the maintenance frequency is reduced, the operation and maintenance costs of the entire system can be effectively reduced, and the production efficiency can be improved.

[0064] The reaction exhaust chamber 5 is connected to a heat exchanger 6.

[0065] The advantages of the above settings are:

[0066] Improve energy utilization efficiency

[0067] Heat recovery and reuse: The gas discharged from the reaction exhaust chamber 5 usually carries a large amount of heat. The heat exchanger 6 can transfer this heat to the low-temperature exhaust gas entering the system or other fluids that need to be preheated. For example, in the exhaust gas treatment of a color coating production line, preheating the exhaust gas entering the reaction exhaust chamber can enable the exhaust gas to reach the reaction temperature faster, reduce additional energy consumption, and lower the operation cost of the entire system.

[0068] Reduce energy consumption: Through heat exchange by the heat exchanger 6, the demand for external energy is reduced. For example, in winter, using the heat of the gas discharged from the reaction exhaust chamber 5 to preheat the fresh air can reduce the heating energy consumption of the HVAC system, achieve effective recycling of energy, and improve the comprehensive energy utilization efficiency.

[0069] Protect equipment and extend service life

[0070] Stabilize the working temperature: The heat exchanger 6 can adjust the temperature of the gas discharged from the reaction exhaust chamber to a temperature range that subsequent equipment can withstand. Prevent high-temperature gas from directly entering subsequent equipment, avoid problems such as degradation of material properties and structural deformation of the equipment due to long-term exposure to high temperatures, and extend the service life of the equipment.

[0071] Reducing thermal stress: Stable temperature changes help reduce thermal stress in equipment caused by thermal expansion and contraction. For example, for some connecting pipes and sealing components, stable temperature can prevent problems such as cracks and leaks due to frequent temperature fluctuations, ensuring the sealing performance and overall stability of the equipment.

[0072] Improving the waste gas treatment effect

[0073] Optimizing reaction conditions: The waste gas whose temperature is adjusted by the heat exchanger 6 can enter the subsequent treatment unit under more suitable reaction temperature conditions. Taking the catalytic oxidation treatment of waste gas as an example, appropriate temperature helps improve the activity and selectivity of the catalyst, enabling pollutants in the waste gas to react more fully with the catalyst, thereby improving the treatment efficiency and purification effect of the waste gas.

[0074] Promoting condensation separation: If the waste gas contains condensable components, the heat exchanger 6 reducing the gas temperature is beneficial to the condensation of these components. For example, when treating waste gas containing volatile organic compounds, reducing the temperature causes the volatile organic compounds to condense into liquids, facilitating their removal from the waste gas through condensation separation equipment and increasing the removal rate of pollutants in the waste gas.

[0075] The monitoring ventilation pipe 7 is connected with a support frame 9.

[0076] The advantages of the above settings are as follows:

[0077] Ensuring monitoring accuracy

[0078] Maintaining the stable position of the ventilation pipe: The support frame 9 can fix the position of the monitoring ventilation pipe 7, preventing it from shaking or shifting due to factors such as air flow impact and vibration. This helps ensure that the monitoring equipment installed on the ventilation pipe is in an accurate measurement position, ensuring the accuracy and reliability of the monitoring data.

[0079] Ensuring stable air flow: A stable ventilation pipe helps maintain the stability of the air flow inside the pipe, avoiding air flow disorder caused by the shaking or deformation of the ventilation pipe, so that the monitoring equipment can accurately measure parameters such as the flow rate and composition of the waste gas, providing accurate data support for the operation and regulation of the waste gas treatment system.

[0080] Enhancing system stability

[0081] Sharing the weight of the pipe: The monitoring ventilation pipe 7 itself has a certain weight, especially in the case of being long or having a large diameter. The support frame 9 can share the weight of the ventilation pipe, reducing the pressure at the pipe connection, avoiding problems such as loosening and leakage at the connection part due to the overweight of the pipe, and improving the stability and sealing performance of the entire ventilation system.

[0082] Resisting external forces: In an industrial environment, the ventilation pipe may be subjected to various external forces, such as wind force, mechanical vibration, etc. The support frame 9 can enhance the structural strength of the ventilation pipe, enabling it to better resist these external forces, preventing the ventilation pipe from deforming or being damaged, and ensuring the normal operation of the ventilation system.

[0083] Facilitating maintenance and management

[0084] Facilitating maintenance operations: The support frame 9 provides good support and fixation for monitoring the ventilation pipe 7, making it more convenient and safe for maintenance personnel to maintain and repair the ventilation pipe and monitoring equipment. Maintenance personnel can more easily access various parts of the ventilation pipe for inspection, repair, component replacement, etc., improving the efficiency of maintenance work.

[0085] Benefiting the pipeline layout: The support frame 9 can reasonably layout and install the monitored ventilation pipe 7 according to actual needs, making the direction of the ventilation pipe more regular and orderly, facilitating connection and coordination with other equipment and pipelines, optimizing the spatial layout of the entire waste gas treatment system, and facilitating the management and maintenance of the system.

[0086] Ensuring safe operation

[0087] Preventing the pipeline from falling: The firm support frame 9 can effectively prevent the monitored ventilation pipe 7 from falling due to unstable installation, avoiding damage to personnel and equipment and ensuring the safety of the production site.

[0088] Reducing potential safety hazards: By stabilizing the ventilation pipe, the support frame 9 helps reduce potential safety hazards that may be caused by the shaking and friction of the ventilation pipe, such as waste gas leakage caused by pipeline wear and rupture, sparks generated by collisions with other objects, etc., improving the safety of the entire system.

[0089] Support rods 20 are respectively connected to the corners at the bottom of the control cabinet 15.

[0090] The advantages of the above settings are as follows:

[0091] Enhancing support stability

[0092] Dispersing the weight: The support rods 20 can evenly disperse the weight of the control cabinet 15 to the ground, preventing the cabinet body from deforming or being damaged due to excessive local stress. Especially for large control cabinets with numerous electrical components installed inside and a large weight, the support rods 20 can effectively bear the weight and ensure the stability of the cabinet body structure.

[0093] Improving the anti-overturning ability: In some environments where there may be vibrations or external forces, such as factory workshops, etc., the support rods 20 can increase the stability of the control cabinet 15, reducing the risk of overturning due to vibrations or external impacts, and ensuring the normal operation of the electrical equipment inside the control cabinet 15.

[0094] Protect the control cabinet body and internal components

[0095] Avoid the influence of ground moisture: Keep a certain distance between the control cabinet 15 and the ground to prevent moisture, accumulated water, etc. on the ground from eroding the cabinet body, avoid rust and corrosion of the cabinet body, and extend the service life of the cabinet body. At the same time, it can also protect the electrical components in the cabinet, prevent faults such as short circuits and electric leakage caused by moisture, and improve the reliability and safety of electrical equipment.

[0096] Prevent ground debris from scratching: During the handling or installation of the control cabinet 15, the support rod 20 can separate the bottom of the cabinet body from the ground, reducing the scratching and damage of the bottom of the cabinet body by ground debris, sharp objects, etc., and protecting the integrity of the cabinet body.

[0097] Facilitate wiring and ventilation

[0098] Convenient for wiring operations: The support rod 20 forms a certain space between the bottom of the control cabinet 15 and the ground, facilitating the entry and exit of electrical lines from the bottom of the cabinet body, and convenient for construction workers to carry out wiring, connection and other operations, making the line layout more neat and standardized, and facilitating later maintenance and repair.

[0099] Improve ventilation conditions: Increase the air circulation space at the bottom of the cabinet body, which is beneficial to the heat dissipation inside the control cabinet 15. Electrical components generate heat during operation, and good ventilation can timely dissipate the heat, reduce the temperature inside the cabinet, ensure that the electrical components work in a suitable temperature environment, and improve their performance and service life.

[0100] Facilitate installation and maintenance

[0101] Provide an operating space: When installing the control cabinet 15, the support rod 20 makes a certain gap between the bottom of the cabinet body and the ground, facilitating construction workers to operate under the cabinet body, such as fixing anchor bolts, connecting pipes, etc. During maintenance, it is also convenient for maintenance personnel to enter the bottom of the cabinet to check the lines, replace components, etc., improving the work efficiency of installation and maintenance.

[0102] Facilitate horizontal adjustment: By adjusting the height of the support rod 20, the levelness of the control cabinet 15 can be conveniently adjusted to ensure that the cabinet body is in a horizontal state, making the installation and operation of the internal electrical components more stable, and avoiding problems such as component damage or performance degradation caused by the inclination of the cabinet body.

[0103] Working principle

[0104] Exhaust gas collection: The sealing cover 1 is installed at the exhaust gas outlet of the color coating equipment to form a relatively enclosed space. After the induced draft fan 3 is started, a negative pressure is formed inside the sealing cover 1. With its strong air extraction ability, the exhaust gas containing VOC generated during the color coating production process is continuously extracted from inside the sealing cover 1, realizing the preliminary collection of the exhaust gas and providing a stable gas source for subsequent treatment.

[0105] Pretreatment: The waste gas extracted by the induced draft fan 3 enters the condenser 4. The condenser 4 exchanges heat between the cooling medium and the waste gas to reduce the temperature of the waste gas. During this process, some high-boiling VOCs reach the saturation state due to the temperature reduction, and then condense into liquid, which is discharged and collected through the drain pipe. After condensation treatment, the content of high-boiling VOCs in the waste gas is greatly reduced, and at the same time, part of the water vapor and impurities are removed, reducing the load of the subsequent treatment device.

[0106] Catalytic reaction: The pretreated waste gas enters the reaction exhaust chamber 5 filled with a new type of catalyst. The new type of catalyst has a strong adsorption and activation ability for VOC molecules in the waste gas. Under the action of the catalyst, the VOC molecules chemically react with oxygen and are decomposed into harmless substances such as carbon dioxide and water.

[0107] Monitoring: The waste gas after the catalytic reaction in the reaction exhaust chamber 5 enters the monitoring ventilation pipe 7. Multiple groups of VOC concentration sensors 8 evenly distributed in the monitoring ventilation pipe 7 start to work, and the VOC concentration in the waste gas is detected in real time. These sensors transmit the monitored concentration data to the PLC controller 17 continuously through electrical signals or other signal transmission methods, providing an accurate data basis for the subsequent decision-making and control of the system.

[0108] Diversion and combustion: The PLC controller 17 receives the data from the VOC concentration sensors 8 and compares and analyzes them with the preset emission standards. When the monitoring data shows that the VOC concentration in the waste gas is lower than the emission standard, the PLC controller 17 issues an instruction to open the exhaust valve 11 and close the return air valve 13, and the waste gas is directly discharged into the atmosphere through the exhaust pipe 12; when the monitored VOC concentration in the waste gas is higher than the emission standard, the PLC controller 17 controls to close the exhaust valve 11 and open the return air valve 13, and the waste gas is introduced into the combustion chamber 14. In the combustion chamber 14, the waste gas burns fully under high-temperature conditions, and the remaining VOCs are completely decomposed into harmless substances before being discharged, ensuring that the finally discharged waste gas fully meets the environmental protection requirements.

[0109] Control: The core control unit of the entire system is the PLC controller 17, which constitutes an intelligent control system in cooperation with the touch screen 19. The operator can set various parameters of the system through the touch screen 19, such as the rotation speed of the induced draft fan 3, the temperature of the condenser 4, the time of the catalytic reaction, etc., and can also view the operating status and monitoring data of the system in real time. The PLC controller 17 automatically adjusts the operating parameters of various devices such as the induced draft fan 3, the condenser 4, the reaction exhaust chamber 5, the exhaust valve 11, the return air valve 13, and the combustion chamber 14 according to the information of the waste gas flow rate, concentration, composition, etc. feedback by the monitoring device and according to the preset control logic, realizing the automatic and intelligent operation of the system and ensuring that the system is always in a high-efficiency and stable working state.

[0110] Embodiment 2

[0111] A novel catalyst, comprising a carrier and an active component supported on the carrier;

[0112] The carrier is an organic-inorganic hybrid material, formed by combining polyaniline and mesoporous silica through in-situ polymerization, and the mass ratio of polyaniline to mesoporous silica is (1:3)-(3:1);

[0113] The active component includes a main active component and a promoter. The main active component is alloy nanoparticles of palladium, ruthenium, and rhodium, and the particle size of the alloy nanoparticles is controlled between 5-10 nanometers. In the alloy nanoparticles of palladium, ruthenium, and rhodium, the atomic ratio of palladium, ruthenium, and rhodium is (3:2:1)-(5:3:2); the promoter contains phosphomolybdic acid and transition metal sulfides, and the mass ratio of phosphomolybdic acid to transition metal sulfides is (1:2)-(2:1). The transition metal sulfides include molybdenum disulfide and tungsten disulfide.

[0114] Example 3

[0115] A method for preparing a novel catalyst, comprising the following steps:

[0116] Preparation of the carrier:

[0117] Dissolve tetraethyl orthosilicate in a mixed solution of ethanol and deionized water, add the template agent cetyltrimethylammonium bromide, and carry out hydrolysis and polycondensation reactions under acidic conditions to form a mesoporous silica precursor;

[0118] Add aniline monomer and initiator ammonium persulfate to the mesoporous silica precursor solution, and through in-situ polymerization reaction, make polyaniline grow in the pores and on the surface of mesoporous silica to form a polyaniline-mesoporous silica hybrid material;

[0119] Remove the template agent by high-temperature calcination to obtain an organic-inorganic hybrid carrier with a regular pore structure;

[0120] The temperature of the hydrolysis and polycondensation reaction is 50-70 °C, and the reaction time is 4-8 hours; the temperature of the high-temperature calcination is 450-550 °C, and the calcination time is 3-5 hours;

[0121] Loading of the active component:

[0122] Loading of the main active component: Dissolve metal salts of palladium, ruthenium, and rhodium in an appropriate solvent, add reducing agent sodium borohydride and protective agent polyvinylpyrrolidone, and under stirring conditions, reduce metal ions to alloy nanoparticles and load them onto the organic-inorganic hybrid carrier. The solvent for dissolving the metal salts is ethylene glycol, the stirring conditions are a rotation speed of 500-1000 revolutions per minute, the reaction temperature is 0-5 °C, and the reaction time is 1-2 hours;

[0123] Promoter component loading: Dissolve phosphomolybdic acid and the precursor of transition metal sulfide in water to form a mixed solution; Immerse the carrier loaded with the main active component into the mixed solution, and load the promoter component precursor onto the carrier by the impregnation method; Then, through hydrothermal reaction, convert the precursor into phosphomolybdic acid and transition metal sulfide to achieve stable loading of the promoter component. The impregnation time is 10 - 14 hours, the temperature of the hydrothermal reaction is 160 - 200 °C, and the reaction time is 10 - 14 hours.

[0124] Example 4

[0125] A method for preparing a new type of catalyst, comprising the following steps:

[0126] Preparation of the carrier:

[0127] In a 250 mL three-necked flask, add 50 mL of ethanol, 10 mL of deionized water, and 15 g of tetraethyl orthosilicate. After stirring evenly, add 1 g of the template agent cetyltrimethylammonium bromide. Then slowly dropwise add 0.5 mol / L hydrochloric acid solution to adjust the pH value to 3 - 4. In a constant temperature water bath at 60 °C, stir at a speed of 300 revolutions per minute to carry out hydrolysis and polycondensation reactions for 6 hours to form a mesoporous silica precursor.

[0128] Transfer the above mesoporous silica precursor solution to a 500 mL reaction kettle, add 5 g of aniline monomer and 3 g of initiator ammonium persulfate, and carry out an in-situ polymerization reaction at 80 °C for 8 hours under nitrogen protection to grow polyaniline in the pores and on the surface of the mesoporous silica to form a polyaniline-mesoporous silica hybrid material.

[0129] Place the obtained hybrid material in a muffle furnace, heat it from room temperature to 500 °C at a heating rate of 5 °C per minute, and calcine it at this temperature for 4 hours to remove the template agent and obtain an organic-inorganic hybrid carrier with a regular pore structure. After detection, the mass ratio of polyaniline to mesoporous silica in the carrier is 1:2.

[0130] Loading of the active component:

[0131] Loading of the main active component: In a 100 mL round-bottom flask, 50 mL of ethylene glycol was added, and 0.3 g of palladium chloride, 0.2 g of ruthenium chloride, and 0.1 g of rhodium chloride were successively dissolved to form a metal salt solution. Under an ice bath condition, a 0.5 mol / L sodium borohydride solution was slowly added dropwise to the solution, and at the same time, 0.5 g of the protective agent polyvinylpyrrolidone was added. The reaction was stirred at a speed of 800 revolutions per minute for 1.5 hours to reduce metal ions to alloy nanoparticles. Then, the prepared organic-inorganic hybrid support was added to the above solution, and stirring was continued for 1 hour to load the alloy nanoparticles onto the support. Observed by transmission electron microscopy (TEM), the particle size of the alloy nanoparticles was between 5 and 10 nanometers, and they were evenly distributed on the surface and in the pores of the support. After detection, the atomic ratio of palladium, ruthenium, and rhodium was 4:3:2.

[0132] Loading of the co-active component: 0.5 g of phosphomolybdic acid and the precursors of 0.5 g of molybdenum disulfide and tungsten disulfide (mass ratio 1:1) were dissolved in 50 mL of deionized water to form a mixed solution. The support loaded with the main active component was immersed in this mixed solution and impregnated at room temperature for 12 hours. Then, the impregnated support was transferred to a reaction kettle and subjected to a hydrothermal reaction at 180 °C for 12 hours to convert the precursors into phosphomolybdic acid and transition metal sulfides, realizing the stable loading of the co-active component. Through X-ray photoelectron spectroscopy (XPS) analysis, it was determined that the co-active component was successfully loaded onto the support, and the mass ratio of phosphomolybdic acid to transition metal sulfides was 1:1.

[0133] Specific testing of catalyst performance

[0134] Preparation before testing:

[0135] Catalyst pretreatment: The novel catalyst prepared in Example 4 was dried in an oven at 120 °C for 2 hours to remove the moisture adsorbed on the surface of the catalyst and ensure the accuracy of the test results. After drying, the catalyst was ground into a uniform powder for better filling into the fixed-bed reactor.

[0136] Preparation of simulated exhaust gas: According to the common components of the exhaust gas from the color coating production line, a high-precision gas mixing device was used to prepare simulated exhaust gas. In addition to containing VOCs with a concentration of 1000 mg / m 3 (the main components are common volatile organic compounds such as toluene and xylene), the simulated exhaust gas also contained a certain proportion of nitrogen as a balance gas and a small amount of oxygen (volume fraction about 10%) to simulate the oxidation environment in the actual exhaust gas.

[0137] Calibration of testing equipment: Conduct a comprehensive calibration of the gas chromatography-mass spectrometry (GC-MS) instrument to ensure that the sensitivity, resolution, and accuracy of the instrument meet the testing requirements. Calibrate the instrument using standard gases and plot a standard curve to accurately measure the concentration of VOCs in the exhaust gas. At the same time, check and debug the temperature control system, flow control system, etc. of the fixed-bed reactor to ensure that the equipment can operate stably during the testing process.

[0138] Testing process:

[0139] Loading the catalyst: Uniformly fill the pretreated catalyst into the fixed-bed reactor to a height of about 2 / 3 of the reactor height, ensuring that the catalyst is evenly distributed in the reactor and the gas can fully contact the catalyst. Load an appropriate amount of quartz sand at both ends of the catalyst to prevent the catalyst from being carried out by the gas flow and ensure that the gas flow passes evenly through the catalyst bed.

[0140] Introducing simulated exhaust gas: Start the simulated exhaust gas supply device and introduce the simulated exhaust gas into the fixed-bed reactor at a space velocity of 10000 h-1. At the same time, raise the temperature in the reactor to 250 °C through the temperature control system and maintain it stable. In the initial stage of introducing the simulated exhaust gas, collect gas samples at the reactor outlet every 15 minutes and analyze the VOC concentration using GC-MS until the outlet VOC concentration stabilizes, indicating that the catalyst has reached a stable catalytic activity state.

[0141] Long-term stability test: After the catalyst reaches a stable activity state, start a continuous 8-hour long-term stability test. Collect gas samples at the reactor inlet and outlet every 1 hour, analyze the VOC concentration using GC-MS, and record the test data. During the test, closely monitor parameters such as the temperature, pressure, and gas flow rate of the reactor to ensure the stability of the test conditions.

[0142] Analysis of test results:

[0143] Calculation of removal rate: According to the VOC concentration data at the reactor inlet and outlet obtained by GC-MS analysis, calculate the removal rate of the catalyst for VOCs using the following formula: Removal rate (%) = (Inlet VOC concentration - Outlet VOC concentration) / Inlet VOC concentration × 100%. After continuous 8-hour testing, the calculated average removal rate of this new catalyst for VOCs reaches over 95%, indicating that the catalyst has excellent catalytic activity.

[0144] Activity stability evaluation: By analyzing the test data collected at different time points, a curve of the VOC removal rate versus time was plotted. It can be seen from the curve that during the continuous 8-hour test, the VOC removal rate always remained above 95%, with a small fluctuation range, indicating that the new catalyst has good activity stability and can maintain high catalytic performance for a long time.

[0145] Product analysis: The gas products at the reactor outlet were analyzed in detail using GC-MS. The results showed that VOCs were mainly decomposed into harmless substances such as carbon dioxide and water, and no obvious by-products were detected, further proving the high efficiency and selectivity of the new catalyst in the catalytic decomposition of VOCs.

[0146] In summary, through the specific tests of the performance of the new catalyst, its excellent catalytic activity, good activity stability and high selectivity in the treatment of VOC waste gas in the color coating production line have been fully verified, and it has broad application prospects.

[0147] The examples given in the present invention are not intended to limit the implementation modes. For those of ordinary skill in the art, other different forms of changes or variations can be made based on the above description. It is not necessary and impossible to enumerate all the implementation modes here, and the obvious changes or variations derived therefrom are still within the protection scope of the present invention.

Claims

1. An intelligent control system for VOC emission monitoring and treatment of a color coating production line, characterized in that, It includes an exhaust gas collection device, a pretreatment device, a catalytic reaction device, a monitoring device, a shunt device, a combustion device, and a control device; The exhaust gas collection device includes a sealing cover (1) and an induced draft fan (3). The sealing cover (1) is arranged at the exhaust gas outlet of the color coating equipment. The induced draft fan (3) is connected to the sealing cover (1) to extract the exhaust gas from the inside of the sealing cover (1) and transport it to the pretreatment device; The pretreatment device includes a condenser (4) connected to the induced draft fan (3). The condenser (4) cools the exhaust gas through a cooling medium to condense part of the high-boiling VOCs into a liquid state and discharges and collects them through a drain pipe; The catalytic reaction device includes a reaction exhaust chamber (5) connected to the condenser (4). The reaction exhaust chamber (5) is filled with a new type of catalyst, and the reaction exhaust chamber (5) decomposes the exhaust gas through the built-in new type of catalyst; The monitoring device includes a monitoring ventilation pipe (7) connected to the exhaust port of the reaction exhaust chamber (5). Multiple groups of evenly distributed VOC concentration sensors (8) are connected inside the monitoring ventilation pipe (7); The shunt device includes a three-way shunt pipe (10) connected to the monitoring ventilation pipe (7). One exhaust port of the three-way shunt pipe (10) is connected to an exhaust pipe (12) through an exhaust valve (11); The combustion device includes a combustion chamber (14) connected to the other exhaust port of the three-way shunt pipe (10) through a return air valve (13); The control device includes a control cabinet (15). A cabinet door (18) is hinged at the opening of the control cabinet (15). A power module (16) and a PLC controller (17) are connected inside the control cabinet (15). A touch screen (19) is inlaid and connected to the cabinet door (18). The induced draft fan (3), the condenser (4), the reaction exhaust chamber (5), the exhaust valve (11), the return air valve (13), the combustion chamber (14), the PLC controller (17), and the touch screen (19) are respectively connected to the power module (16). The induced draft fan (3), the condenser (4), the reaction exhaust chamber (5), the VOC concentration sensors (8), the exhaust valve (11), the return air valve (13), the combustion chamber (14), and the touch screen (19) are respectively connected to the PLC controller (17); The new type of catalyst includes a carrier and active components supported on the carrier; The carrier is an organic-inorganic hybrid material formed by combining polyaniline and mesoporous silicon through in-situ polymerization; The active components include a main active component and a co-active component. The main active component is an alloy nanoparticle of palladium, ruthenium, and rhodium, and the particle size of the alloy nanoparticle is controlled between 5 and 10 nanometers; the co-active component includes phosphomolybdic acid and transition metal sulfides, and the transition metal sulfides include molybdenum disulfide and tungsten disulfide.

2. The VOC emission monitoring and treatment system for a color coating production line with intelligent control according to claim 1, wherein, A filter screen (2) is installed at the air inlet of the sealing cover (1).

3. The VOC emission monitoring and treatment system for a color coating production line with intelligent control according to claim 1, characterized in that, The reaction exhaust chamber (5) is connected to a heat exchanger (6).

4. An intelligent control VOC emission monitoring and treatment system for a color coating production line according to claim 1, characterized in that, The monitoring ventilation pipe (7) is connected to a support frame (9).

5. An intelligent control VOC emission monitoring and treatment system for a color coating production line according to claim 1, characterized in that, Support rods (20) are respectively connected to the bottom corners of the control cabinet (15).

6. The intelligent control color coating production line VOC emission monitoring and treatment system according to claim 1, characterized in that, In the carrier, the mass ratio of polyaniline to mesoporous silicon is (1:3) - (3:1).

7. An intelligent control VOC emission monitoring and treatment system for a color coating production line according to claim 1, characterized in that, Among the main active components, in the alloy nanoparticles of palladium, ruthenium, and rhodium, the atomic ratio of palladium, ruthenium, and rhodium is (3:2:1)-(5:3:2).

8. An intelligent control VOC emission monitoring and treatment system for a color coating production line according to claim 1, characterized in that, Among the co-active components, the mass ratio of phosphomolybdic acid to transition metal sulfide is (1:2)-(2:1).

9. The VOC emission monitoring and treatment system for a color coating production line with intelligent control according to claim 1, characterized in that, The preparation method of the novel catalyst includes the following steps: Preparation of the support: Dissolve tetraethyl orthosilicate in a mixed solution of ethanol and deionized water, add the template agent cetyltrimethylammonium bromide, and carry out hydrolysis and polycondensation reactions under acidic conditions to form a mesoporous silicon precursor; Add aniline monomer and initiator ammonium persulfate to the mesoporous silicon precursor solution, and through in-situ polymerization reaction, make polyaniline grow in the pores and on the surface of mesoporous silicon to form a polyaniline-mesoporous silicon hybrid material; Remove the template agent by high-temperature calcination to obtain an organic-inorganic hybrid support with a regular pore structure; Loading of the active components: Loading of the main active components: Dissolve metal salts of palladium, ruthenium, and rhodium in an appropriate solvent, add the reducing agent sodium borohydride and the protecting agent polyvinylpyrrolidone, and under stirring conditions, reduce the metal ions to alloy nanoparticles and load them onto the organic-inorganic hybrid support; Loading of the co-active components: Dissolve phosphomolybdic acid and the precursor of transition metal sulfide in water to form a mixed solution; immerse the support loaded with the main active components in this mixed solution, and through the impregnation method, load the co-active component precursor onto the support; then, through hydrothermal reaction, convert the precursor into phosphomolybdic acid and transition metal sulfide to achieve the stable loading of the co-active components.

10. The VOC emission monitoring and treatment system for a color coating production line with intelligent control according to claim 9, characterized in that, In the preparation step of the support, the temperature of the hydrolysis and polycondensation reaction is 50-70 °C, and the reaction time is 4-8 hours; the temperature of the high-temperature calcination is 450-550 °C, and the calcination time is 3-5 hours; In the loading step of the main active components, the solvent for dissolving the metal salts is ethylene glycol, the stirring condition is a rotation speed of 500-1000 revolutions per minute, the reaction temperature is 0-5 °C, and the reaction time is 1-2 hours; In the loading step of the co-active components, the impregnation time is 10-14 hours, the temperature of the hydrothermal reaction is 160-200 °C, and the reaction time is 10-14 hours.

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