An exhaust gas treatment device for industrial boilers

Abstract

The invention relates to an exhaust gas treatment device for industrial boilers, which is applied to the technical field of exhaust gas treatment devices. The device adopts a honeycomb ceramic-based hexagonal prism catalyst tube to improve mass transfer efficiency. A composite anode plate integrates ICCP cathode protection and plasma electrochemical regeneration functions to inhibit catalyst corrosion and activate it in situ. The composite anode plate adopts a titanium-based porous skeleton and has a built-in special material to generate micro-discharge plasma. A cathode current collecting plate adopts a stainless steel mesh plate and a conductive carbon coating to improve corrosion resistance. A potential reference hole adopts a multi-level branching structure to achieve multi-point in-situ detection. A regeneration liquid circulation system uses a sulfuric acid solution to dissolve and remove surface sediments. An intelligent control system integrates multiple functions to achieve full life cycle management of the catalyst, improves denitration and desulfurization effects, prolongs the life of the catalyst, and achieves intelligent and precise control of the regeneration process.

Description

Technical Field

[0001] The present invention relates to an exhaust gas treatment device for an industrial boiler, and in particular to an exhaust gas treatment device for an industrial boiler applied in the technical field of exhaust gas treatment devices. Background Art

[0002] With the continuous improvement of environmental protection requirements, the treatment of industrial boiler exhaust gas has become an important issue. In the existing technology, the exhaust gas treatment equipment mainly focuses on desulfurization and denitrification, but the deactivation problem of catalysts has always plagued the industry. The traditional catalyst regeneration method often requires the catalyst to be disassembled and regenerated offline, which not only increases the operating cost, but also affects the production continuity.

[0003] Chinese invention patent CN109012081B discloses an industrial boiler exhaust gas denitration device, which achieves high-efficiency denitration by squeezing rubber shrapnel through an elliptical wheel to spray out washing liquid. However, the device fails to solve the problem of catalyst deactivation and still needs to be shut down to replace the catalyst after long-term operation.

[0004] Chinese invention patent CN117883929B proposes a device and process for treating and recovering tail gas from the C5 processing industry chain, which mainly classifies and treats and recovers hydrocarbon tail gas containing hydrogen, oxygen and hydrogen-free. However, this method mainly focuses on the recycling of tail gas and lacks effective measures for the protection and regeneration of catalysts.

[0005] The above designs achieve exhaust gas treatment and recovery through different methods, but there are still certain limitations. For example, they fail to effectively solve the problem of catalyst deactivation and cannot achieve online regeneration of the catalyst, resulting in high equipment maintenance costs and low operating efficiency. In addition, the existing technology is not comprehensive enough for the protection and monitoring of catalysts, making it difficult to achieve intelligent management of the entire life cycle of the catalyst. Summary of the invention

[0006] In view of the above-mentioned prior art, the technical problem to be solved by the present invention is how to design an industrial boiler exhaust gas treatment device that can realize online catalyst regeneration, extend catalyst service life, improve denitrification and desulfurization efficiency, and reduce operating costs.

[0007] In order to solve the above problems, the present invention provides an exhaust gas treatment device for industrial boilers, comprising a controller and a flue gas pipe, wherein a catalyst bed is clamped on the inner wall of the flue gas pipe, the catalyst bed comprises a fixed tube, a plurality of catalyst tubes are fixedly connected in the fixed tube, the plurality of catalyst tubes are all hexagonal prism structures, the catalyst tubes are made of honeycomb ceramics and loaded with vanadium-based catalysts, a catalytic channel is provided in the catalyst tube, a composite anode plate corresponding to the catalytic channel is provided in the catalyst bed, the composite anode plate is a hexagonal prism structure, the composite anode plate comprises a substrate, anode dissolution grooves and plasma generating grooves are alternately provided on the substrate, the plasma generating grooves are filled with ferroelectric ceramic powders, and the surface of the ferroelectric ceramic powders is coated with a plasma catalyst, a potential reference hole is provided in the substrate, an exhaust port is fixedly connected to the top of the flue gas pipe, an air inlet is fixedly connected to the bottom of the flue gas pipe, a regeneration liquid circulation system is fixedly connected to the outer wall of the flue gas pipe, and the controller comprises a DC power supply, an electrochemical detection module, a plasma power supply and an intelligent control system.

[0008] As a further improvement of the present application, a reference electrode is provided in the potential reference hole, and the reference electrode is made of a Luggin capillary. The reference electrode includes a main capillary, and a primary branch is fixedly connected to the bottom end of the main capillary, and a secondary branch is fixedly connected to the bottom end of the primary branch. The bottom end of the primary branch is located at the midpoint of the potential reference hole, and the end opening of the secondary branch is 1-5 mm away from the surface of the composite anode plate, and the axis of the secondary branch coincides with the axis of the potential reference hole. Sealing blocks are fixedly connected to both ends of the potential reference hole, and the secondary branch passes through the sealing block.

[0009] As a further improvement of the present application, an electrolytic cell is fixedly connected to the top of the flue gas pipe, and the electrolytic cell is connected to the top of the main capillary. A standard electrode for calibrating the reference electrode potential measurement is fixedly connected to the inlet and outlet of the catalytic channel. The standard electrode is a saturated calomel electrode. The potential measurement value of the reference electrode is calibrated by measuring the potential difference between the reference electrode and the standard electrode. The electrolytic cell and the reference electrode are both filled with electrolyte.

[0010] As a further improvement of the present application, the top and bottom ends of the catalyst bed are fixedly connected to cathode current collecting plates, the cathode current collecting plates are made of stainless steel mesh, the inner wall of the catalytic channel is coated with a conductive coating, the conductive coating is a conductive carbon coating, prepared by an impregnation method, and the two ends of the conductive coating are electrically connected to the cathode current collecting plates respectively.

[0011] As another improvement of the present application, the regeneration liquid circulation system includes a regeneration liquid storage tank, and the top and bottom ends of the regeneration liquid storage tank are respectively fixedly connected with a spray pipe and a return pipe, the spray pipe and the return pipe extend to the top and bottom ends of the flue gas pipe respectively away from one end of the regeneration liquid storage tank, and the extended parts are respectively fixedly connected with a spray box and a return box, the spray box includes a plurality of spray rings, the plurality of spray rings are interconnected by pipelines, the plurality of spray rings are arranged one by one corresponding to the catalytic channels, and nozzles are opened at the bottom ends of the plurality of spray rings.

[0012] As another improved supplement of the present application, the regeneration liquid storage tank is filled with regeneration liquid, which is a sulfuric acid solution with a concentration of 1-5wt% and a pH value of 0-1, and is used to dissolve carbon deposits and inhibitors on the catalyst surface.

[0013] As another improved supplement to the present application, the positive output end of the DC power supply is electrically connected to the anode dissolution tank in the composite anode plate, the negative output end is electrically connected to the cathode current collecting plate, the electrochemical detection module is electrically connected to the reference electrode and the standard electrode, and is used to monitor the surface potential and electrochemical characteristics of the catalyst in real time, the high-voltage output end of the plasma power supply is electrically connected to the plasma generating tank on the surface of the composite anode plate, and the intelligent control system is electrically connected to the DC power supply, the electrochemical detection module and the plasma power supply respectively.

[0014] As another improvement of the present application, the intelligent control system includes a PLC controller and a host computer software system. The PLC controller is connected to the electrochemical detection module through a data acquisition card to collect catalyst surface potential and electrochemical impedance data in real time. The host computer software system has data processing, process control, and human-computer interaction functions. According to the collected data and preset control strategies, control instructions are issued to adjust the output of the DC power supply and the working state of the plasma power supply.

[0015] In summary, this application has the following beneficial effects:

[0016] The catalyst bed layer adopts honeycomb ceramic-based hexagonal catalyst tubes, which have large specific surface area and high mass transfer efficiency. The flue gas is fully in contact with the catalyst, ensuring excellent denitration and desulfurization effects. The composite anode plate integrates ICCP cathodic protection and plasma electrochemical regeneration functions. The alternating distribution of the anode dissolution tank and the plasma generation tank is cleverly used to form a uniform ICCP protection electric field and plasma regeneration field on the catalyst surface, which can inhibit the electrochemical corrosion of the catalyst and delay the deactivation process. At the same time, the catalyst surface can be activated in situ to restore the acidic position and redox activity. The composite anode plate adopts a titanium-based porous skeleton with built-in BaTiO 3 Ferroelectric Ceramics and LaCoO 3 Plasma catalysts generate a large amount of micro-discharge plasma under the action of high-voltage pulse electric fields, activating the catalyst surface and achieving high regeneration efficiency.

[0017] The cathode current collecting plate is made of stainless steel mesh and the conductive coating is made of conductive carbon coating, which not only improves the uniformity of ICCP current distribution, but also has excellent corrosion resistance and can adapt to the harsh working conditions of flue gas. The potential reference hole is equipped with a Luggin capillary reference electrode, and a multi-level branching structure is used to connect with different catalyst tubes to achieve multi-point and in-situ detection of the catalyst surface potential, providing reliable data support for ICCP process optimization control and catalyst regeneration process monitoring and diagnosis. The regeneration liquid circulation system uses sulfuric acid solution as the regeneration liquid, which fully reacts with the carbon accumulation and poisoning species on the catalyst surface, dissolves and removes catalyst surface deposition, and further improves the regeneration effect. The design of the spray ring and reflux device ensures the uniform distribution and recycling of the regeneration liquid, reducing the consumption of regeneration liquid and the discharge of waste liquid.

[0018] The intelligent control system integrates multiple functions such as ICCP cathodic protection, electrochemical detection, plasma regeneration, and chemical regeneration of regeneration liquid, realizing intelligent management of the entire life cycle of vanadium-based catalysts. The control system can collect state parameters such as catalyst surface potential and impedance in real time, diagnose the degree of catalyst deactivation, and automatically optimize ICCP protection potential and regeneration control parameters to achieve closed-loop optimization control of the regeneration process and improve regeneration efficiency and accuracy. The catalyst electrochemical management system and regeneration method provided by this patent are simple to operate, require small equipment investment, and have low operating costs. They can realize in-situ and online regeneration of the catalyst without stopping the operation of the boiler. They have significant technical advantages and economic value for flue gas treatment of industrial boilers such as coal-fired power plants, and are suitable for large-scale promotion and application. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is the overall structure diagram of this application;

[0020] Figure 2 This is the appearance structure diagram of this application;

[0021] Figure 3 This is an overall exploded view of this application;

[0022] Figure 4 Partial explosion for this application Figure 1 ;

[0023] Figure 5 Partial explosion for this application Figure 2 ;

[0024] Figure 6 Partial explosion for this application Figure 3 ;

[0025] Figure 7 Partial explosion for this application Figure 4 ;

[0026] Figure 8 This is the front view of the application;

[0027] Fig. 9 For this application Figure 8 Middle AA section view;

[0028] Fig.10 For this application Fig. 9 Middle BB section view;

[0029] Fig.11 For this application Fig.10 Middle CC section view;

[0030] Fig.12 For this application Fig.10 Middle DD section view.

[0031] Description of the numbers in the figure:

[0032] 1. Flue gas pipe; 101. Exhaust port; 102. Air inlet; 2. Catalyst bed; 201. Fixed tube; 202. Catalyst tube; 203. Catalytic channel; 3. Composite anode plate; 301. Substrate; 302. Anode dissolution tank; 303. Plasma generating tank; 304. Potential reference hole; 4. Reference electrode; 401. Main capillary; 402. Primary branch; 403. Secondary branch; 5. Electrolytic cell; 6. Cathode current collecting plate; 7. Conductive coating; 8. Regeneration liquid circulation system; 801. Regeneration liquid storage tank; 802. Spray pipe; 803. Reflux pipe; 804. Spray box; 805. Reflux box; 8041. Spray ring. DETAILED DESCRIPTION

[0033] Four implementation modes of the present application are described in detail below with reference to the accompanying drawings.

[0034] Example 1

[0035] An exhaust gas treatment device for industrial boilers, such as Figure 1 and Fig.11 As shown, it includes a controller and a flue gas pipe 1, and a catalyst bed 2 is clamped on the inner wall of the flue gas pipe 1.

[0036] In this embodiment, if Figure 1 , Figure 7 and Fig.11As shown, the catalyst bed 2 includes a fixed tube 201, in which a plurality of catalyst tubes 202 are fixedly connected. The catalyst tubes 202 are fixed to the inner wall of the fixed tube 201 by means of high-temperature ceramic glue. The high-temperature ceramic glue has excellent high-temperature resistance and chemical stability, and can work stably for a long time in a flue gas environment. A special positioning tool is used in the fixing process to ensure that each catalyst tube 202 is evenly distributed. The plurality of catalyst tubes 202 are all hexagonal prism structures, made of honeycomb ceramics, and loaded with vanadium-based catalysts. A catalytic channel 203 is opened in each catalyst tube 202. The flue gas is in full contact with the catalyst in the catalytic channel 203, and catalytic reactions such as denitrification and desulfurization occur.

[0037] A composite anode plate 3 corresponding to the catalytic channel 203 is provided in the catalyst bed 2. The composite anode plate 3 is also a hexagonal prism structure, including a substrate 301. Anode dissolution grooves 302 and plasma generating grooves 303 are alternately provided on the substrate 301. The anode dissolution grooves 302 are used to provide ICCP cathode protection current, and the plasma generating grooves 303 are filled with ferroelectric ceramic powder. The surface of the ferroelectric ceramic powder is coated with a plasma catalyst for generating high-energy plasma to promote catalyst regeneration. A potential reference hole 304 is also provided in the substrate 301 for arranging a reference electrode to monitor the surface potential of the catalyst.

[0038] like Figures 1 to 12 As shown, the top and bottom ends of the catalyst bed 2 are fixedly connected to a cathode collector plate 6, which is made of a stainless steel mesh plate and has excellent conductivity and corrosion resistance. The inner wall of the catalytic channel 203 is coated with a conductive coating 7, which is a conductive carbon coating prepared by an impregnation method. Both ends of the conductive coating 7 are electrically connected to the cathode collector plate 6, so that the entire catalyst bed 2 forms a unified cathode, which is convenient for receiving ICCP protection current.

[0039] The top of the flue gas pipe 1 is fixedly connected with an exhaust port 101, and the bottom is fixedly connected with an air inlet 102. The flue gas enters from the air inlet 102, is processed by the catalyst bed 2, and is discharged from the exhaust port 101. The outer wall of the flue gas pipe 1 is fixedly connected with a regeneration liquid circulation system 8 for providing regeneration liquid for chemical regeneration of the catalyst.

[0040] The controller is the core of the entire tail gas treatment device, including a DC power supply, an electrochemical detection module, a plasma power supply and an intelligent control system, wherein the positive output end of the DC power supply is electrically connected to the anode dissolution tank 302 in the composite anode plate 3, and the negative output end is electrically connected to the cathode current collecting plate 6 to provide ICCP cathode protection current. The electrochemical detection module is electrically connected to the reference electrode and the standard electrode to monitor the surface potential and electrochemical characteristics of the catalyst in real time. The high-voltage output end of the plasma power supply is electrically connected to the plasma generating tank 303 on the surface of the composite anode plate 3 to provide the high-voltage pulse power required for plasma discharge. The intelligent control system is electrically connected to the DC power supply, the electrochemical detection module and the plasma power supply respectively to achieve coordinated control of each component.

[0041] The intelligent control system includes a PLC controller and a host computer software system. The PLC controller is connected to the electrochemical detection module through a data acquisition card to collect catalyst surface potential and electrochemical impedance data in real time. The host computer software system has functions such as data processing, process control, and human-computer interaction. According to the collected data and preset control strategies, it issues control instructions to adjust the output of the DC power supply and the working state of the plasma power supply, thereby realizing automatic control of ICCP cathodic protection, electrochemical regeneration, and plasma regeneration.

[0042] The flue gas enters the flue gas pipe 1 from the air inlet 102, fully contacts with the catalyst in the catalyst bed 2, and catalytic reactions such as denitrification and desulfurization occur. The purified flue gas is discharged from the exhaust port 101. During the catalytic process, the anode dissolution tank 302 in the composite anode plate 3 continuously releases the anode dissolution current, and a loop is formed through the conductive coating 7 and the cathode current collecting plate 6, thereby applying cathodic protection to the catalyst surface and inhibiting the electrochemical corrosion of the catalyst.

[0043] The electrochemical detection module monitors the characteristic parameters such as the catalyst surface potential and electrochemical impedance in real time through the reference electrode and the standard electrode. The intelligent control system diagnoses the degree of catalyst deactivation based on this. When the catalytic activity drops to a preset threshold, the control system starts the regeneration program: the regeneration liquid circulation system 8 sprays the regeneration liquid onto the catalyst surface to dissolve carbon deposits and poisoning species; at the same time, the plasma power supply applies a high-voltage pulse to the plasma generating slot 303 on the surface of the composite anode plate 3 to generate high-energy plasma to activate the catalyst surface. As the regeneration process proceeds, the electrochemical detection module feeds back the recovery of the catalyst activity, and the control system optimizes the regeneration parameters based on this, such as the regeneration liquid composition, plasma discharge power, etc., to achieve closed-loop optimization control of the regeneration process.

[0044] The exhaust gas treatment device provided in this embodiment adopts a composite anode plate 3 to integrate ICCP cathodic protection and plasma electrochemical regeneration functions, which can effectively inhibit the deactivation of the catalyst and realize the in-situ regeneration of the deactivated catalyst, thereby greatly improving the service life of the catalyst. The catalyst tube 202 adopts a hexagonal honeycomb ceramic structure with a large specific surface area and high mass transfer efficiency, thereby ensuring an excellent purification effect. The cathode collecting plate 6 adopts a stainless steel mesh plate, and the conductive coating 7 adopts a conductive carbon coating, thereby improving the uniformity of the current distribution and having excellent corrosion resistance, thereby adapting to the harsh working conditions of the flue gas. The introduction of the electrochemical detection module and the intelligent control system realizes the online diagnosis of the catalyst deactivation state and the real-time optimization of the regeneration process, thereby making the operation of the exhaust gas treatment device more intelligent and efficient. This technical solution can significantly improve the flue gas purification level of industrial boilers such as coal-fired power plants, reduce the emission of atmospheric pollutants, and has good environmental and social benefits.

[0045] Example 2

[0046] This embodiment provides an exhaust gas treatment device for an industrial boiler. Based on Embodiment 1, the structure and working principle of the composite anode plate 3 and its related components are further described in detail.

[0047] like Figure 1 and Fig.11 As shown, the composite anode plate 3 is a hexagonal prism structure, which matches the structure of the catalyst tube 202. The composite anode plate 3 includes a substrate 301. The substrate 301 is preferably a titanium substrate, and the surface is anodized to form a dense titanium oxide coating with excellent conductivity and corrosion resistance.

[0048] The substrate 301 is provided with anode dissolution grooves 302 and plasma generation grooves 303 alternately. The anode dissolution grooves 302 are rectangular groove-shaped structures, and the groove walls are coated with iridium-tantalum oxide coatings, which serve as ICCP anode dissolution coatings to provide stable and long-lasting anode dissolution currents. The plasma generation grooves 303 are also rectangular groove-shaped structures, and are filled with ferroelectric ceramic powders, preferably BaTiO 3 Powder, particle size 1-5μm, ferroelectric ceramic powder surface coated with LaCoO by sol-gel method 3 Plasma catalyst, coating thickness 50-100nm, under the stimulation of high-voltage pulse electric field, ferroelectric ceramics produce polarization, forming a large number of micro-discharge plasmas, and the catalyst coating further promotes the generation of active particles in the plasma. 3 The catalyst has a unique perovskite structure and variable valence properties. During the plasma discharge process, LaCoO 3 Surface La 3 + and Co 3 + / Co 4+ ion pairs can quickly capture and release electrons, promoting the electron avalanche effect. At the same time, LaCoO 3 The oxygen vacancies can adsorb oxygen molecules, which are more easily ionized under the action of a strong electric field to produce oxygen free radicals. These mechanisms work together to improve the efficiency of generating active particles in the plasma.

[0049] A potential reference hole 304 is provided in the substrate 301. The potential reference hole 304 is a blind hole structure. The depth is 1 / 2 of the thickness of the substrate 301 and the diameter is 1-2 mm. A reference electrode 4 is provided in the potential reference hole 304. The reference electrode 4 adopts a Luggin capillary structure and is filled with a saturated KCl solution. The reference electrode 4 includes a main capillary 401, a primary branch 402 and a secondary branch 403. The main capillary 401 is placed outside the flue gas pipe 1 and is connected to the electrolytic cell 5. The primary branch 402 is connected to the electrolytic cell 5. 02 and the secondary branch 403 are placed in the flue gas pipe 1, the secondary branch 403 is connected to the middle of the potential reference hole 304, the end opening of the secondary branch 403 maintains a distance of 1-2mm from the surface of the composite anode plate 3, and is sealed to the wall of the potential reference hole 304 through a ceramic seal, the main capillary 401 and the primary branch 402 are coated with a 0.1mm thick polytetrafluoroethylene film on the outside to prevent smoke interference, and the secondary branch 403 is made of an ultra-fine glass capillary with an outer diameter of 0.5mm.

[0050] An electrolytic cell 5 is provided on the top of the flue gas pipe 1. The electrolytic cell 5 is filled with a saturated KCl solution and is connected to the main capillary 401 to form a rehydration and potential transfer path for the reference electrode 4. A standard electrode is also provided at the inlet and outlet of the catalyst tube 202, preferably a saturated calomel electrode. By measuring the potential difference between the reference electrode 4 and the standard electrode, the potential measurement value of the reference electrode 4 can be calibrated to improve the measurement accuracy.

[0051] During the operation of the exhaust gas treatment device, the cathodic protection current from the DC power supply is dissolved through the iridium-tantalum oxide coating on the anode dissolution tank 302 to form a uniformly distributed anode current field, and then passes through the conductive coating 7 and the cathode collector plate 6 loop to form cathode polarization on the catalyst surface, thereby inhibiting the electrochemical corrosion of the catalyst.

[0052] When the electrochemical detection module determines that the catalyst activity decreases and needs to be regenerated, the plasma power supply applies a high voltage pulse to the ferroelectric ceramic powder in the plasma generating slot 303, causing it to produce a dielectric potential well effect, forming a large number of micro-discharge plasmas. 3 Under the action of the catalyst, a large number of high-energy electrons, free radicals and other active particles are generated, diffused to the catalyst surface, and chemically reacted with the adsorbed pollutants, causing them to oxidize, decompose and desorb, thereby achieving the purpose of in-situ regeneration of the catalyst.

[0053] During the ICCP cathodic protection and plasma regeneration process, the reference electrode 4 monitors the potential changes on the catalyst surface at different positions in real time through the Luggin capillary network. The main capillary 401 introduces the KCl solution into the pipe network and transmits the detected catalyst potential signal to the electrolytic cell 5. By analyzing the potential change curves of different reference electrodes 4, the uniformity of ICCP current distribution and the dynamic process of catalyst activity regeneration can be understood, providing data support for the intelligent control system to optimize ICCP current density and plasma discharge parameters.

[0054] This embodiment describes in detail the structural design and working principle of the composite anode plate 3 integrating ICCP anode dissolution and plasma generation functions. The design of alternating arrangement of anode dissolution slots 302 and plasma generation slots 303 can form a uniform ICCP protection electric field and plasma regeneration field on the catalyst surface, significantly improving the catalyst's anti-deactivation ability and regeneration ability. The potential reference hole 304 has a built-in reference electrode 4, and a Luggin capillary branch network is used to connect with different catalyst tubes 202, so that multi-point and in-situ detection of the catalyst surface potential can be achieved, and the dynamic characteristics of the ICCP process and the catalyst regeneration process can be fully reflected, providing a reliable basis for intelligent optimization control. This technical solution realizes the precise regulation of ICCP cathodic protection and plasma electrochemical regeneration processes through the integration of functional materials and microstructure design, which can significantly extend the service life of the catalyst, improve the flue gas purification efficiency, and reduce the frequency of catalyst replacement. It has significant technical innovation and practical value.

[0055] Example 3

[0056] This embodiment provides an exhaust gas treatment device for an industrial boiler. Based on Embodiment 1, the structure and working principle of the regeneration liquid circulation system 8 are further described in detail.

[0057] like Figure 1 and Fig.11 As shown, the regeneration liquid circulation system 8 includes a regeneration liquid storage tank 801, a spray pipe 802, a reflux pipe 803, a spray box 804 and a reflux box 805, wherein the regeneration liquid storage tank 801 is a PE plastic barrel for containing the regeneration liquid, and the regeneration liquid is preferably a 1-5wt% sulfuric acid solution, and the pH value is controlled between 0-1 to dissolve the carbon deposits and poisoning substances on the catalyst surface.

[0058] The top of the regeneration liquid storage tank 801 is connected to a spray pipe 802, and the bottom is connected to a return pipe 803. The spray pipe 802 and the return pipe 803 are both made of acid- and alkali-resistant PVC pipes. The other ends of the spray pipe 802 and the return pipe 803 are respectively connected to the spray box 804 at the top of the flue gas pipe 1 and the return box 805 at the bottom.

[0059] The spray box 804 is a hollow flat box-shaped structure made of stainless steel 304, and its length is equal to the inner diameter of the flue gas pipe 1. A plurality of spray holes are evenly spaced at the bottom of the spray box 804, and each spray hole is connected to a spray ring 8041. The plurality of spray rings 8041 are interconnected through PVC hoses to form a parallel distribution structure. Each spray ring 8041 is annular, and its inner diameter matches the outer diameter of the main capillary 401. Eight nozzles are evenly arranged on the ring, and the nozzle diameter is 0.5 mm. The spray ring 8041 is arranged at the inlet of the catalyst tube 202 to spray the regeneration liquid evenly on the catalyst surface.

[0060] The reflux box 805 is a hollow flat box-shaped structure made of stainless steel 304, and its size is the same as that of the spray box 804. The reflux box 805 is close to the bottom of the flue gas pipe 1, and a liquid return hole is opened on the top of the reflux box 805. The liquid return hole is connected to the reflux pipe 803 to lead the regeneration liquid and reaction products flowing down the catalyst surface back to the regeneration liquid storage tank 801 to achieve the recycling of the regeneration liquid. A sedimentation tank with a volume of 50L is set inside the regeneration liquid storage tank 801 through a partition. The solid impurities generated during the circulation process are removed by gravity sedimentation. An overflow port is provided on the upper part of the sedimentation tank. An activated carbon filter is fixedly connected to the overflow port to further remove soluble impurities. The filtered regeneration liquid continues to be used. After each regeneration, the sediment in the sedimentation tank is discharged and treated as hazardous waste. When the pH value of the regeneration liquid rises to above 2, a new acid solution is replaced.

[0061] Electric regulating valves and flow meters are provided on the regeneration liquid storage tank 801, the spray pipe 802 and the return pipe 803 to control the flow and circulation speed of the regeneration liquid. A liquid level meter and a thermometer are also provided in the regeneration liquid storage tank 801 to monitor the liquid level and temperature of the regeneration liquid in real time to ensure the normal operation of the regeneration liquid circulation system 8.

[0062] When the catalyst needs to be regenerated, the control system sends a start command to the regeneration liquid circulation system 8. First, the sulfuric acid solution in the regeneration liquid storage tank 801 enters the spray box 804 through the spray pipe 802 under the action of pressure, and then is evenly sprayed on the surface of the catalyst tube 202 through the spray ring 8041 and the nozzle, and is fully in contact with the catalyst.

[0063] The sulfuric acid solution reacts chemically with the carbon deposits and poisoning species (such as As, Pb, etc.) on the catalyst surface, dissolving and removing them, and generating soluble sulfates. The regeneration liquid containing the reaction products flows to the bottom of the flue gas pipe 1 under the action of gravity, and returns to the regeneration liquid storage tank 801 through the reflux box 805 and the reflux pipe 803. During the circulation process, the regeneration liquid continuously dissolves and carries the carbon deposits and poisoning species on the catalyst surface, thereby restoring its activity.

[0064] After the regeneration liquid circulates for a certain period of time, the control system closes the electric regulating valve to stop the circulation, and then introduces high-pressure air into the spray pipe 802 to blow and dry the catalyst tube 202. At the same time, the remaining regeneration liquid and reaction products are blown into the reflux box 805 and discharged through the reflux pipe 803. Finally, dry and clean air is introduced into the flue gas pipe 1 to further dry the catalyst layer and complete the regeneration process.

[0065] This embodiment describes in detail the structure and working process of the regeneration liquid circulation system 8. Sulfuric acid solution is used as the regeneration liquid, which can effectively dissolve the carbon deposits and poisoning species on the catalyst surface, especially for V 2 O 5 -WO 3 / TiO 2 The regeneration effect of vanadium-based catalysts is remarkable. The design of spray box 804 and spray ring 8041 can realize the uniform distribution of regeneration liquid on the catalyst surface and improve the regeneration efficiency. The setting of reflux box 805 and reflux pipe 803 realizes the recycling of regeneration liquid and reduces the consumption of regeneration liquid and waste liquid discharge.

[0066] The regeneration liquid circulation system 8 can work in conjunction with ICCP cathodic protection and plasma electrochemical regeneration to form a complete catalyst regeneration scheme, wherein ICCP cathodic protection can effectively inhibit the electrochemical corrosion of the catalyst and delay the deactivation process; plasma electrochemical regeneration can in situ activate the catalyst surface, restore the acidic sites and redox activity; and the regeneration liquid chemical regeneration can deeply remove carbon deposits and poisoning species on the catalyst surface, further improving the regeneration effect. The three complement each other and work synergistically, which can significantly extend the service life of the catalyst, reduce the frequency of replacement, and reduce operating costs. The regeneration liquid circulation system 8 has a simple structure and is easy to operate. It is suitable for industrial promotion and application, and can provide efficient and economical catalyst regeneration technology support for flue gas purification of industrial boilers such as coal-fired power plants.

[0067] Example 4

[0068] like Figure 1 and Fig.11 As shown, a catalyst regeneration method for an exhaust gas treatment device of an industrial boiler comprises the following steps:

[0069] S1: When the catalyst is deactivated, a sulfuric acid solution with a concentration of 1-5wt% and a pH value of 0-1 is added to the regeneration liquid storage tank 801 as the regeneration liquid;

[0070] S2: Turn on the DC power supply to apply an anode dissolution current to the anode dissolution tank 302 in the composite anode plate 3, and form cathode polarization on the catalyst surface through the conductive coating 7 and the cathode current collecting plate 6 to inhibit electrochemical corrosion of the catalyst;

[0071] S3: Turn on the plasma power supply, apply high voltage pulses to the ferroelectric ceramic powder in the plasma generating slot 303 on the surface of the composite anode plate 3, generate a dielectric potential well effect, and form a large number of micro-discharge plasmas on the catalyst surface. The plasma is 3 The catalyst generates high-energy electrons and free radicals, activating the catalyst surface;

[0072] S4: Start the regeneration liquid circulation system 8, so that the regeneration liquid enters the spray box 804 through the spray pipe 802, and then is evenly sprayed on the surface of the catalyst tube 202 through the spray ring 8041 and the nozzle, fully contacts with the catalyst and reacts chemically to dissolve the carbon deposits and poisoning substances on the catalyst surface;

[0073] S5: The regeneration liquid containing the reaction product flows to the bottom of the flue gas pipe 1 under the action of gravity, and returns to the regeneration liquid storage tank 801 through the reflux box 805 and the reflux pipe 803, so as to realize the recycling of the regeneration liquid;

[0074] S6: After the regeneration liquid circulates for a certain period of time, the DC power supply, plasma power supply and regeneration liquid circulation system 8 are turned off, and high-pressure air is introduced into the spray pipe 802 to purge and dry the catalyst tube 202. At the same time, the residual regeneration liquid and reaction products are blown into the reflux box 805 and discharged through the reflux pipe 803;

[0075] S7: Dry and clean air is introduced into the flue gas pipe 1 to further dry the catalyst layer and complete the regeneration process.

[0076] By utilizing the structural features of the composite anode plate 3, the regeneration liquid circulation system 8 and the controller, the deactivated denitrification and desulfurization catalysts can be efficiently regenerated through the synergistic effect of cathode protection, plasma activation and chemical regeneration of the regeneration liquid, thereby extending their service life.

[0077] During the flue gas treatment process, with the continuous deposition of carbon deposits and poisoning species, the catalyst activity gradually decreases. When its denitrification and desulfurization efficiency is lower than the set threshold, the controller determines that the catalyst is deactivated and needs to start the regeneration program.

[0078] First, according to step S1, a sulfuric acid solution with a pH value of 0-1 and a 1-5 wt % is added into the regeneration liquid storage tank 801 as the regeneration liquid to prepare for chemical regeneration.

[0079] Then, according to step S2, the controller applies an anode dissolution current to the anode dissolution tank 302 in the composite anode plate 3 through a DC power supply. The anode dissolution current forms a loop through the conductive coating 7 and the cathode current collecting plate 6, forming cathode polarization on the catalyst surface. The cathode polarization can increase the electron density on the catalyst surface, inhibit its electrochemical corrosion and dissolution, and delay the deactivation process.

[0080] Next, according to step S3, the controller applies a high voltage pulse to the ferroelectric ceramic powder in the plasma generating slot 303 on the surface of the composite anode plate 3 through a plasma power supply, with a frequency of 20-50kHz and a peak voltage of 2-5kV. Under the action of the high voltage pulse, the ferroelectric ceramic powder generates a dielectric potential well effect, so that a large amount of micro-discharge plasma is formed on its surface. The micro-discharge plasma is formed on the LaCoO 3 Under the action of the catalyst, active particles such as high-energy electrons, O free radicals and N free radicals are generated. These active particles migrate to the catalyst surface and activate the acidic sites and redox active sites of the catalyst through chemical adsorption, polarization, charge transfer and other effects, thereby restoring its catalytic activity.

[0081] Then, according to step S4, the controller turns on the regeneration liquid circulation system 8, starts the regeneration liquid pump, and allows the sulfuric acid solution in the regeneration liquid storage tank 801 to enter the spray box 804 through the spray pipe 802, and then be evenly sprayed on the surface of the catalyst tube 202 through the spray ring 8041 and the nozzle, so as to fully contact the catalyst. The sulfuric acid solution undergoes an oxidation-reduction reaction with the carbon deposits and poisoning species such as As and Pb on the catalyst surface, so that they are dissolved and removed and converted into soluble sulfates.

[0082] According to step S5, the regeneration liquid containing the reaction product flows along the inner wall of the catalyst tube 202 to the bottom of the flue gas pipe 1 under the action of gravity, and finally collects in the reflux box 805, and returns to the regeneration liquid storage tank 801 through the reflux pipe 803, so as to realize the recycling of the regeneration liquid. The regeneration liquid circulation process lasts for 20-30 minutes to ensure sufficient chemical regeneration effect.

[0083] After the regeneration is completed, according to step S6, the controller turns off the DC power supply, plasma power supply and regeneration liquid circulation system 8, stops the cathode protection current output, plasma discharge and regeneration liquid circulation, and then introduces high-pressure air into the spray pipe 802 to blow and dry the inner and outer surfaces of the catalyst tube 202 for 5-10 minutes. At the same time, the residual regeneration liquid and reaction products are blown into the reflux box 805 and discharged through the reflux pipe 803. The high-pressure air pressure range is 0.6-0.8MPa and the flow rate is 50-100 m³ / h. This pressure range is sufficient to blow the residual liquid on the catalyst surface without causing mechanical damage to the catalyst. The air is degreased and dehumidified, and the dew point temperature is lower than -40°C to ensure that no new pollutants are introduced.

[0084] Finally, according to step S7, dry clean air with a moisture content of less than 1% is introduced into the flue gas pipe 1 for 10-20 minutes to further dry the catalyst layer and complete the regeneration process.

[0085] The catalyst regeneration method provided in this embodiment can efficiently regenerate the denitrification and desulfurization catalysts and significantly extend their service life through the multiple synergistic effects of cathode protection, plasma activation and chemical regeneration of the regeneration liquid.

[0086] The cathodic protection process utilizes the anode dissolution tank 302 in the composite anode plate 3 to apply an anode dissolution current to form a protective cathode polarization on the catalyst surface, which can slow down the electrochemical corrosion and dissolution of the catalyst, delay its deactivation process, and lay the foundation for deep regeneration.

[0087] The plasma activation process utilizes the ferroelectric ceramics in the plasma generating slot 303 on the surface of the composite anode plate 3 to generate a dielectric potential well effect under the action of a high-voltage pulse, thereby forming a high-density micro-discharge plasma on the catalyst surface. The high-energy electrons and free radicals generated by the micro-discharge plasma can activate the acidic sites and redox active sites of the catalyst, thereby restoring its catalytic activity.

[0088] The regeneration liquid chemical regeneration process utilizes the regeneration liquid circulation system 8 to evenly spray the sulfuric acid solution onto the catalyst surface to dissolve and remove carbon deposits and poisoning species, further improving the regeneration effect of the catalyst.

[0089] In view of current practical needs, the above-mentioned implementation mode adopted in this application is not limited to the scope of protection. Various changes made within the knowledge scope of technical personnel in this field without departing from the concept of this application still fall within the scope of protection of the present invention.

Claims

1. An exhaust gas treatment device for an industrial boiler, characterized in that: The invention comprises a controller and a flue gas pipe (1), wherein a catalyst bed (2) is clamped on the inner wall of the flue gas pipe (1), wherein the catalyst bed (2) comprises a fixed tube (201), wherein a plurality of catalyst tubes (202) are fixedly connected in the fixed tube (201), wherein the plurality of catalyst tubes (202) are all hexagonal prism structures, wherein the catalyst tubes (202) are made of honeycomb ceramics and loaded with vanadium-based catalysts, wherein catalytic channels (203) are provided in the catalyst tubes (202), wherein the catalyst bed (2) is provided with composite anode plates (3) corresponding to the catalytic channels (203), wherein the composite anode plates (3) are hexagonal prism structures, and wherein the composite anode plates (203) are provided in the catalyst bed (2). 3) comprising a substrate (301), wherein the substrate (301) is provided with anode dissolution grooves (302) and plasma generation grooves (303) alternately, wherein the plasma generation grooves (303) are filled with ferroelectric ceramic powder, and the surface of the ferroelectric ceramic powder is coated with a plasma catalyst, wherein a potential reference hole (304) is provided in the substrate (301), wherein the top end of the flue gas pipe (1) is fixedly connected to an exhaust port (101), and the bottom end is fixedly connected to an air inlet (102), wherein the outer wall of the flue gas pipe (1) is fixedly connected to a regeneration liquid circulation system (8), and wherein the controller comprises a DC power supply, an electrochemical detection module, a plasma power supply and an intelligent control system; The regeneration liquid circulation system (8) comprises a regeneration liquid storage tank (801), the top and bottom of the regeneration liquid storage tank (801) are respectively fixedly connected with a spray pipe (802) and a return pipe (803), the spray pipe (802) and the return pipe (803) are respectively extended to the top and bottom of the flue gas pipe (1) at one end away from the regeneration liquid storage tank (801), and the extended parts are respectively fixedly connected with a spray box (804) and a return box (805), the spray box (804) comprises a plurality of spray rings (8041), the plurality of spray rings (8041) are interconnected through pipelines, the plurality of spray rings (8041) are arranged in one-to-one correspondence with the catalytic channels (203), and the bottom ends of the plurality of spray rings (8041) are all provided with nozzles; The positive output end of the DC power supply is electrically connected to the anode dissolution tank (302) in the composite anode plate (3), the negative output end is electrically connected to the cathode current collecting plate (6), the electrochemical detection module is electrically connected to the reference electrode (4) and the standard electrode, and is used to monitor the surface potential and electrochemical characteristics of the catalyst in real time, the high-voltage output end of the plasma power supply is electrically connected to the plasma generating tank (303) on the surface of the composite anode plate (3), and the intelligent control system is electrically connected to the DC power supply, the electrochemical detection module and the plasma power supply respectively; The intelligent control system includes a PLC controller and a host computer software system. The PLC controller is connected to an electrochemical detection module through a data acquisition card to collect catalyst surface potential and electrochemical impedance data in real time. The host computer software system has data processing, process control, and human-computer interaction functions. According to the collected data and a preset control strategy, control instructions are issued to adjust the output of the DC power supply and the working state of the plasma power supply.

2. The tail gas treatment device for industrial boilers according to claim 1, characterized in that: A reference electrode (4) is arranged in the potential reference hole (304), the reference electrode (4) is made of a Luggin capillary, the reference electrode (4) comprises a main capillary (401), the bottom end of the main capillary (401) is fixedly connected to a primary branch (402), the bottom end of the primary branch (402) is fixedly connected to a secondary branch (403), the bottom end of the primary branch (402) is located at the midpoint of the potential reference hole (304), the end opening of the secondary branch (403) is 1-5 mm away from the surface of the composite anode plate (3), and the axis of the secondary branch (403) coincides with the axis of the potential reference hole (304), both ends of the potential reference hole (304) are fixedly connected to sealing blocks, and the secondary branch (403) passes through the sealing block.

3. The tail gas treatment device for industrial boilers according to claim 2, characterized in that: An electrolytic cell (5) is fixedly connected to the top of the flue gas pipe (1), and the electrolytic cell (5) is connected to the top of the main capillary (401). A standard electrode for calibrating the potential measurement of the reference electrode (4) is fixedly connected to the inlet and outlet of the catalytic channel (203). The standard electrode is a saturated calomel electrode. The potential measurement value of the reference electrode (4) is calibrated by measuring the potential difference between the reference electrode (4) and the standard electrode. The electrolytic cell (5) and the reference electrode (4) are both filled with electrolyte.

4. The tail gas treatment device for industrial boilers according to claim 1, characterized in that: The top and bottom ends of the catalyst bed (2) are fixedly connected to a cathode current collecting plate (6), the cathode current collecting plate (6) being made of a stainless steel mesh plate, the inner wall of the catalytic channel (203) being coated with a conductive coating (7), the conductive coating (7) being a conductive carbon coating prepared by an impregnation method, and the two ends of the conductive coating (7) being electrically connected to the cathode current collecting plate (6) respectively.

5. The tail gas treatment device for industrial boilers according to claim 1, characterized in that: The regeneration liquid storage tank (801) contains regeneration liquid, which is a sulfuric acid solution with a concentration of 1-5wt% and a pH value of 0-1, and is used to dissolve carbon deposits and inhibitors on the catalyst surface.

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