A flue gas treatment system

Abstract

The application discloses a flue gas treatment system, which comprises a centrifugal separation assembly and a filtering assembly. The centrifugal separation assembly is provided with a vertical separation tank, and the top end and the middle part of the tank are respectively connected with an air inlet pipe and an air outlet pipe in tangential direction, so that large particle dust in flue gas can be separated by centrifugal force and timely dust removal can be realized. The filtering assembly is arranged in a sealed hollow shell, and first, second and third filtering units are coaxially arranged in sequence along the flue gas flow direction. The first filtering unit adopts a borosilicate glass fiber felt wave folding structure with specific parameters and a nano alumina coating, can intercept fine particles and has corrosion resistance; the second filtering unit is a 400cpsi honeycomb ceramic carrier filled with composite particle structure, and can adsorb acid gases in flue gas; and the third filtering unit is a Mn-ZSM-5 molecular sieve structure with specific specific surface area and pore size, and is provided with a Pt / Rh bimetallic catalytic layer on the surface, so that trace harmful substances can be deeply catalytically degraded. The application adopts a hierarchical purification and sealed butt joint structure, can efficiently purify flue gas in stages, has good treatment efficiency and operation stability, and can ensure that flue gas meets the discharge standard.

Description

Technical Field

[0001] This invention relates to the field of flue gas purification and treatment, specifically to a flue gas treatment system that can be widely applied to high-temperature and harmful flue gas purification scenarios in various fields such as lithium battery production, chemical industry, and petrochemical industry. Background Technology

[0002] Industrial sectors such as chemical, petrochemical, and lithium battery production generate dust containing large particles, fine particulate matter, SO2, and NO. x High-temperature flue gas containing acidic gases, VOCs, heavy metals, and other trace harmful substances; among them, emergency flue gas from lithium batteries and chemical processes have complex compositions and fluctuate greatly in operating conditions, requiring more stringent standards for purification efficiency, operational stability, and compliance with emission standards. Direct discharge of such flue gas can easily cause air pollution and secondary safety accidents. In existing purification systems, filter components are subject to rapid wear and tear and frequent replacement due to particle blockage, chemical corrosion, and airflow impact, which not only increases maintenance costs but also restricts the long-term stable operation of the system and makes it difficult to meet the industry's high emission standards. With the continuous upgrading of environmental emission standards, gradient-stage deep purification of flue gas and long-life operation of filter components have become core industry requirements. Existing flue gas treatment solutions generally suffer from technical bottlenecks such as poor deep purification effect, insufficient synergy of multi-stage purification, and easy wear and tear of filter components. How to balance efficient deep purification of flue gas with long-term use of filter components is a problem that the industry urgently needs to overcome.

[0003] Existing technologies generally suffer from drawbacks such as rapid filter component wear, short service life, insufficient deep purification capacity, and inability to meet high emission standards. For example, the inertial separation combined with baghouse dust collection system (CN112588059B) fails to completely remove large particles, which are easily re-entrained by the airflow. Furthermore, it lacks structures for intercepting fine particles and treating harmful gases, leading to filter component clogging and aging, shortening its lifespan, and failing to achieve deep flue gas purification. While the integrated flue gas purification system (CN109663428B) achieves integrated desulfurization and dust removal, its poorly connected tiered units, uneven flue gas distribution, and lack of efficient pre-treatment for impurities and specialized treatment structures for acidic gases and trace harmful substances result in easily clogged and corroded filter components, high maintenance costs, and unsuitability for complex flue gas purification scenarios. The multi-stage desulfurization-washing-carbon capture system (CN117018837A) focuses on harmful gas removal but lacks a pre-particle separation stage. Coarse and fine particles directly enter the downstream units, easily causing filter component clogging and rapid decline in purification efficiency. It also fails to achieve graded treatment of pollutants, resulting in insufficient purification synergy and an inability to meet high emission standards across multiple fields.

[0004] Meanwhile, existing flue gas treatment technologies suffer from drawbacks such as weak synergy in staged purification, poor adaptability to operating conditions, and unoptimized structural parameters, further exacerbating filter component wear and limiting the improvement of purification efficiency. Some solutions focus only on particulate matter retention, with residual corrosive gases accelerating filter media aging and damage; some solutions prioritize gas-phase mass transfer, neglecting the compatibility of filter media with high-temperature corrosive flue gas, and the structural parameters of the filter units are not systematically optimized, easily leading to filter media damage and unstable purification efficiency; most solutions fail to form a synergistic architecture of pre-particle separation, staged filtration, and deep purification, making it impossible to target different pollutants. They are unable to effectively remove fine particles, acidic gases, and trace harmful substances, and the unbalanced airflow resistance and excessive filtration load shorten component lifespan, failing to meet the actual purification needs of high-efficiency, low-maintenance, long-cycle, and high-standard flue gas purification in the lithium battery, chemical, and petrochemical industries.

[0005] Therefore, in response to the problems of insufficient deep purification of flue gas, poor synergy of multi-stage purification, easy wear and tear of filter components, and short service life of existing technologies, it is a key technical problem that urgently needs to be solved in this field to develop a technical solution that can realize gradient and graded purification of flue gas, ensure long-term operation of filter components, and ensure stable compliance of flue gas. Summary of the Invention

[0006] The purpose of this invention is to overcome the above-mentioned technical deficiencies and propose a flue gas treatment system that solves the technical problems of insufficient synergy of multi-stage filtration, poor deep purification effect, difficulty in efficiently removing trace harmful substances, acidic gases and small particles from flue gas, and inability to achieve high-standard emission compliance of flue gas in the existing technology.

[0007] To achieve the above-mentioned technical objectives, the present invention adopts the following technical solution: This invention provides a flue gas treatment system, including a centrifugal separation component and a filtration component. The centrifugal separation component includes a vertical separation tank, an inlet pipe, and an outlet pipe. A cleaning port is provided at the bottom of the separation tank. The inlet pipe is sealed and connected to the top side wall of the separation tank along the tangential direction of the tank's circumference. The outlet pipe is sealed and connected to the middle side wall of the separation tank along the tangential direction of the tank's circumference. The filtration component includes a sealed hollow shell, a primary filtration unit, a secondary filtration unit, and a tertiary filtration unit. The inlet end of the shell is sealed and connected to the outlet end of the outlet pipe. An outlet is provided at the far end of the shell. The primary filtration unit has a density of 0.28 g / cm³, a thickness of 50 ± 2 mm, a folding amplitude of 12 mm, and a surface coated with a nano-Al₂O₃ coating. The filter structure is a continuous wave-shaped folded fiber composed of borosilicate glass fiber felt. The secondary filter unit is a honeycomb carrier filling structure with Na2CO3 particles and Ca(OH)2 / Al2O3 composite particles in the internal pores of a 400cpsi honeycomb ceramic carrier. The tertiary filter unit is a regular vertical channel array molecular sieve filter structure made of Mn-ZSM-5 molecular sieve with a specific surface area ≥450m² / g, pore size 0.55nm, and vertical channel spacing 2mm, and a surface loaded with a 0.8wt%Pt / Rh bimetallic catalyst layer. The primary, secondary, and tertiary filter units are coaxially sealed and connected in sequence along the flue gas flow direction. The outer periphery of each filter unit is sealed and attached to the inner wall of the shell and is integrally fixed and built into the inner cavity of the shell.

[0008] In some embodiments, the primary filtration unit is a continuous wave-shaped folded fiber filtration structure made of borosilicate glass fiber mat. The glass fiber mat has a density of 0.28 g / cm³, a thickness of 50 ± 2 mm, a folding amplitude of 12 mm, and the folding peaks and valleys are regularly arranged along the flue gas flow direction. The spacing and depth of the folding peaks and valleys remain consistent throughout the entire filtration unit.

[0009] In some embodiments, the surface of the borosilicate glass fiber felt is uniformly sprayed with a nano-Al2O3 coating, which covers the entire filtration working surface, including folded peaks and valleys and the two side slopes. The coating thickness is 1-3 μm, which is used to adsorb small particles in flue gas and prevent the fiber felt from being chemically corroded.

[0010] In some embodiments, the borosilicate glass fiber mat has a fiber diameter of 8-12 μm, an inter-fiber porosity of 85%-90%, and a folded structure formed by continuous indentation molding. The transition arc radius between the folded peaks and valleys is 2-3 mm to maintain structural stability and filtration uniformity.

[0011] In some embodiments, the secondary filtration unit includes a honeycomb ceramic carrier and filling particles. The honeycomb ceramic carrier is a 400 cpsi honeycomb ceramic carrier with a square pore cross-section and a pore wall thickness of 0.2-0.3 mm. The filling particles include Na2CO3 particles and Ca(OH)2 / Al2O3 composite particles, which are mixed in a molar ratio of 1:0.8-1.2, with a particle size of 100-200 μm, uniformly and tightly filling the voids in the carrier pores, and a filling density of 0.6-0.8 g / cm³.

[0012] In some embodiments, the mass ratio of Ca(OH)2 to Al2O3 in the Ca(OH)2 / Al2O3 composite particles is 1:2-3, and the particles are prepared by co-precipitation. The particle surface has a mesoporous structure with a mesopore diameter of 5-10 nm, which is used to enhance the adsorption capacity for acidic gases and heavy metals.

[0013] In some embodiments, the three-stage filtration unit is a regular vertical channel array molecular sieve filtration structure made of Mn-ZSM-5 molecular sieve. The molecular sieve has a specific surface area ≥450m² / g, a pore size of 0.55nm, a vertical channel spacing of 2mm, a channel diameter of 0.5-0.8mm, a channel wall thickness of 0.3-0.5mm, and a metal catalyst layer uniformly loaded on the surface and inner wall of the channel with a catalyst layer thickness of 0.5-1μm.

[0014] In some embodiments, the metal catalyst layer is a Pt / Rh bimetallic catalyst layer, with a mass ratio of Pt to Rh of 2:1-3:1 and a loading of 0.8 wt%. The catalyst layer is uniformly attached to the surface of the molecular sieve and the inner wall of the channel by impregnation and is calcined at 500-600℃ to form stable catalytic active sites.

[0015] In some embodiments, the inner wall of the separation tank has a conical surface surrounding the cleaning port, the cone angle of the conical surface being 30°-45°, converging from top to bottom towards the center of the cleaning port, and the inner wall being polished with a surface roughness Ra≤0.8μm to ensure that particles smoothly slide down the conical surface to the cleaning port.

[0016] In some embodiments, the centrifugal separation assembly further includes a sealing valve, which is a pneumatic or electric butterfly valve, sealed and installed at the ash removal port. The valve body is connected to the ash removal port flange. The valve can be opened and closed independently, with an opening and closing response time of ≤2 seconds and a sealing pressure of ≥0.6MPa when closed. When opened, it is used to discharge the collected particulate matter, and when closed, it is used to maintain a negative or positive pressure environment in the separation tank.

[0017] Compared with existing technologies, the flue gas treatment system provided by this invention achieves graded purification of flue gas through the synergistic design of centrifugal separation components and three-stage filtration components. The vertical separation tank, combined with tangentially arranged inlet and outlet pipes, efficiently separates large dust particles from the flue gas using centrifugal force. The bottom cleaning port promptly discharges collected dust, preventing dust accumulation from affecting separation efficiency. The three-stage filtration units are sequentially connected along the flue gas flow direction. The first-stage corrugated folded fiber filter structure, with its specific density, thickness, and folding parameters, combined with a nano-Al2O3 coating, efficiently intercepts fine particles and possesses corrosion resistance. The second-stage honeycomb carrier filling structure, through a specific ratio of Na2CO3 and composite particles, specifically adsorbs acidic gases in the flue gas. The third-stage regular vertical channel array molecular sieve filter structure, combined with a Pt / Rh bimetallic catalytic layer, deeply purifies trace harmful substances in the flue gas and achieves catalytic degradation. The sealed connection design of each component effectively prevents flue gas leakage, comprehensively improving the efficiency and stability of flue gas treatment and ensuring that the treated flue gas meets emission standards. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the flue gas treatment system provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the separation tank structure provided in an embodiment of the present invention; Explanation of reference numerals in the attached drawings: Centrifugal separation component 1, separation tank 11, air inlet pipe 12, air outlet pipe 13, valve 14, dust removal port 15, filter component 2, shell 21, air outlet 211, primary filter unit 22, glass fiber felt 221, secondary filter unit 23, honeycomb ceramic carrier 231, tertiary filter unit 24, molecular sieve 241. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0020] To address the technical problems of insufficient synergy in multi-stage filtration and inadequate deep purification in existing flue gas treatment systems, which make it difficult to efficiently remove trace harmful substances, acidic gases, and fine particles from flue gas and achieve high-standard emission compliance, this invention provides a flue gas treatment system. This system, through the coordinated operation of centrifugal separation component 1 and filter component 2, and relying on the layered purification design of a three-stage filtration unit, achieves gradient purification and deep treatment of flue gas, significantly improving the flue gas purification effect and ensuring that all indicators of the treated flue gas meet emission requirements.

[0021] It should be noted that the flue gas treatment system of this invention can be widely applied to flue gas purification scenarios in various fields, such as emergency flue gas treatment in lithium battery production workshops, flue gas purification in chemical production processes, and tail gas treatment in the petrochemical industry. For ease of explanation, the following description will only focus on its application in emergency flue gas treatment in lithium battery production workshops; the principle of its application in other fields such as chemicals and petrochemicals is essentially the same as that applied to emergency flue gas treatment in lithium battery production workshops, and will not be repeated here.

[0022] Please see Figure 1 , Figure 1 This is a schematic diagram of a flue gas treatment system according to an embodiment of the present invention. The flue gas treatment system includes a centrifugal separation component 1 and a filter component 2. The centrifugal separation component 1 includes a vertical separation tank 11, an air inlet pipe 12, and an air outlet pipe 13. The vertical separation tank 11 has a dust removal port 15 at its bottom end. The air inlet pipe 12 is sealed and connected to the top side wall of the vertical separation tank 11 along the tangent direction of the tank body. The air outlet pipe 13 is sealed and connected to the middle side wall of the vertical separation tank 11 along the tangent direction of the tank body. The filter component 2 includes a sealed hollow shell 21, a primary filter unit 22, a secondary filter unit 23, and a tertiary filter unit 24. The air inlet end of the shell 21 is sealed and connected to the air outlet end of the air outlet pipe 13. An air outlet 211 is opened at the far end of the shell 21. The primary filter unit 22 is a continuous corrugated folded fiber filter structure with a density of 0.28 g / cm³. The system consists of a borosilicate glass fiber felt 221 with a thickness of 50±2mm, a folding amplitude of 12mm, and a surface coated with a nano-Al2O3 coating. The secondary filter unit 23 is a honeycomb carrier-filled structure, composed of a 400cpsi honeycomb ceramic carrier 231 and Na2CO3 particles and Ca(OH)2 / Al2O3 composite particles filled in its internal channels. The tertiary filter unit 24 is a regular vertical channel array molecular sieve 241 filter structure, made of Mn-ZSM-5 molecular sieve 241 with a specific surface area ≥450m² / g, a pore size of 0.55nm, and a vertical channel spacing of 2mm. Its surface has a negative 0.8wt% Pt / Rh bimetallic catalyst layer. The primary filter unit 22, the secondary filter unit 23, and the tertiary filter unit 24 are sequentially and coaxially sealed together along the flue gas flow direction. The outer periphery of each filter unit is sealed and attached to the inner wall of the shell 21 and is integrally fixed and built into the inner cavity of the shell 21.

[0023] This embodiment achieves graded purification of flue gas through the coordinated design of centrifugal separation component 1 and three-stage filtration component 2. The vertical separation tank 11, together with the tangentially arranged inlet pipe 12 and outlet pipe 13, can efficiently separate large dust particles in the flue gas using centrifugal force. The bottom dust removal port 15 can promptly discharge the collected dust, preventing dust accumulation from affecting the separation efficiency. The primary filtration unit 22, the secondary filtration unit 23, and the tertiary filtration unit 24 are sequentially connected along the flue gas flow direction. The primary wave-shaped folded fiber filter structure, with its specific density, thickness, and folding parameters, combined with the glass fiber felt 221 with a nano-Al2O3 coating, can efficiently intercept small particles and has corrosion resistance. The secondary honeycomb carrier filling structure, through the honeycomb ceramic carrier 231 and the internal specific ratio of particles, can specifically adsorb acidic gases in the flue gas. The tertiary regular vertical channel array molecular sieve 241 filter structure, combined with the Pt / Rh bimetallic catalytic layer, can deeply purify trace harmful substances in the flue gas and achieve catalytic degradation. The sealed connection design of each component effectively prevents flue gas leakage, improving the overall efficiency and stability of flue gas treatment and ensuring that the treated flue gas meets emission standards.

[0024] In some embodiments, the primary filter unit 22 is a continuous wave-shaped folded fiber filter structure composed of borosilicate glass fiber felt 221. The glass fiber felt 221 has a density of 0.28 g / cm³, a thickness of 50±2 mm, and a folding amplitude of 12 mm. The folding peaks and valleys are regularly arranged along the flue gas flow direction, and the spacing and depth of the folding peaks and valleys remain consistent throughout the filter unit. This embodiment further improves filtration performance and structural stability by optimizing the folding structure details of the primary filter unit 22. The continuous wave-shaped folding design, combined with the regularly arranged folding peaks and valleys and the consistent peak-valley spacing and depth, significantly increases the effective area of ​​the filtration working surface, allowing flue gas to flow evenly through the primary filter unit 22. This avoids filtration dead zones and local blockages caused by excessively high local flue gas flow rates. At the same time, the regular folding structure also improves the structural strength of the primary filter unit 22, reduces the wear and tear on the filter structure caused by flue gas impact, and ensures the long-term stable filtration effect of the primary filter unit 22, laying a good foundation for subsequent multi-stage filtration.

[0025] In some embodiments, the borosilicate glass fiber felt 221 is uniformly coated with a nano-Al2O3 coating with a thickness of 1-3 μm, uniformly covering the entire filtration working surface, including folded peaks and valleys and the sloping sides. This coating is used to adsorb tiny particles in the flue gas and prevent the glass fiber felt 221 from being chemically corroded. This embodiment addresses the adsorption efficiency and corrosion resistance issues of the primary filtration unit 22 by spraying a nano-Al2O3 coating onto the surface of the borosilicate glass fiber felt 221. The nano-Al2O3 coating uniformly covers the entire filtration working surface, including folded peaks and valleys and the sloping sides. Its high specific surface area effectively adsorbs tiny particles in the flue gas, further improving dust removal efficiency. At the same time, the nano-Al2O3 coating has excellent chemical corrosion resistance, which can isolate acidic substances and harmful gases in the flue gas from corroding the borosilicate glass fiber felt 221, preventing aging and damage to the glass fiber felt 221, extending the service life of the primary filtration unit 22, and ensuring the stability of filtration performance.

[0026] In some embodiments, the borosilicate glass fiber felt 221 has a fiber diameter of 8-12 μm and an inter-fiber porosity of 85%-90%. The folded structure is formed by continuous indentation, and the transition radius between the fold peaks and valleys is 2-3 mm to maintain structural stability and filtration uniformity. This embodiment achieves a balance between filtration efficiency and flow resistance while improving structural stability by optimizing the fiber parameters and folding process of the borosilicate glass fiber felt 221. The 8-12 μm fiber diameter and 85%-90% inter-fiber porosity reduce flue gas flow resistance while ensuring effective interception of fine particles, avoiding excessive system energy consumption. The continuously indented folded structure and the 2-3 mm transition radius effectively avoid stress concentration at the folds, preventing damage and detachment of the primary filtration unit 22 during flue gas impact and long-term use, while maintaining the filtration uniformity of the entire primary filtration unit 22, ensuring that each filter surface can function fully.

[0027] In some embodiments, the secondary filtration unit 23 includes a honeycomb ceramic carrier 231 and filling particles. The honeycomb ceramic carrier 231 is of 400 cpsi specification, with a square pore cross-section and a pore wall thickness of 0.2-0.3 mm. The filling particles include Na2CO3 particles and Ca(OH)2 / Al2O3 composite particles, mixed in a molar ratio of 1:(0.8-1.2), with a particle size of 100-200 μm, uniformly and tightly filling the pores of the honeycomb ceramic carrier 231, with a filling density of 0.6-0.8 g / cm³. This embodiment significantly improves the adsorption efficiency and stability of acidic gases by clearly defining the parameters of the honeycomb ceramic carrier 231 and the configuration of the filling particles in the secondary filtration unit 23. The 400cpsi honeycomb ceramic carrier 231, with its reasonable pore cross-section and wall thickness, provides ample filling space, ensures smooth flue gas flow, and possesses sufficient structural strength. Na2CO3 particles and Ca(OH)2 / Al2O3 composite particles are mixed in a specific molar ratio. Combined with a particle size of 100-200μm and a reasonable filling density, the filling particles can be uniformly and tightly filled into the pores of the honeycomb ceramic carrier 231, increasing the contact area between the particles and the flue gas. This allows for efficient adsorption of acidic gases (such as SO2 and NOx) in the flue gas, prevents the loss of filling particles, and improves the adsorption stability and service life of the secondary filter unit 23.

[0028] In some embodiments, the mass ratio of Ca(OH)2 to Al2O3 in the Ca(OH)2 / Al2O3 composite particles is 1:(2-3), and the particles are prepared by co-precipitation. The particle surface has a mesoporous structure with a mesopore diameter of 5-10 nm, which enhances the adsorption capacity for acidic gases and heavy metals. This embodiment further enhances the adsorption capacity and applicability of the secondary filtration unit 23 by optimizing the ratio, preparation method, and microstructure of the Ca(OH)2 / Al2O3 composite particles. The specific mass ratio of Ca(OH)2 and Al2O3, combined with the co-precipitation method, gives the composite particles both the acidic gas neutralization capacity of Ca(OH)2 and the structural stability of Al2O3. The 5-10 nm mesoporous structure on the particle surface significantly increases the specific surface area of ​​the particles, which not only improves the adsorption capacity for acidic gases but also effectively adsorbs heavy metal ions in flue gas, reduces secondary heavy metal pollution, expands the purification range of the secondary filtration unit 23, and improves the overall flue gas purification effect.

[0029] In some embodiments, the three-stage filtration unit 24 is a regular vertical channel array molecular sieve 241 filtration structure made of Mn-ZSM-5 molecular sieve 241. The molecular sieve 241 has a specific surface area ≥450m² / g, a pore size of 0.55nm, a vertical channel spacing of 2mm, a channel diameter of 0.5-0.8mm, and a wall thickness of 0.3-0.5mm. A metal catalyst layer with a thickness of 0.5-1μm is uniformly loaded on the surface and inner wall of the channels. This embodiment provides a good foundation for the deep purification of flue gas by optimizing the molecular sieve 241 parameters and channel structure of the three-stage filtration unit 24. The high specific surface area (≥450m² / g) and suitable pore size (0.55nm) of Mn-ZSM-5 molecular sieve 241 enable it to efficiently adsorb trace harmful substances (such as VOCs and residual microparticles) in flue gas. The regular vertical channel array design, combined with reasonable channel spacing, diameter and wall thickness, ensures smooth flow of flue gas, reduces flow resistance, and allows flue gas to fully contact the surface of molecular sieve 241 and the inner wall of the channels, avoiding purification dead zones. The uniformly loaded metal catalyst layer provides sufficient active sites for the subsequent catalytic degradation of harmful substances, enhancing the deep purification capability of the three-stage filtration unit 24.

[0030] In some embodiments, the metal catalyst layer is a Pt / Rh bimetallic catalyst layer with a Pt to Rh mass ratio of (2:1) to (3:1) and a loading of 0.8 wt%. The catalyst layer is uniformly attached to the surface of the molecular sieve 241 and the inner wall of the channel by impregnation and then calcined at 500-600℃ to form stable catalytic active sites. This embodiment significantly improves the catalytic activity and stability of the tertiary filtration unit 24 by optimizing the ratio, loading, and preparation process of the Pt / Rh bimetallic catalyst layer. Pt and Rh are combined in a specific mass ratio to form a synergistic catalytic effect, which significantly improves the catalytic degradation efficiency of harmful pollutants (such as NOx and VOCs) in flue gas compared to a single metal catalyst layer. The 0.8wt% loading balances catalytic efficiency and cost control, avoiding resource waste and cost increases caused by excessive loading. The impregnation method combined with a 500-600℃ calcination process enables the catalyst layer to be uniformly and firmly attached to the surface of molecular sieve 241 and the inner wall of the channel, forming stable catalytic active sites, extending the service life of the catalyst layer, and ensuring the long-term stable catalytic purification effect of the three-stage filtration unit 24.

[0031] In some embodiments, the inner wall of the vertical separator 11 has a conical surface surrounding the cleaning port 15. The cone angle of the conical surface is 30°-45°, converging from top to bottom towards the center of the cleaning port 15. The inner wall is polished to a surface roughness Ra≤0.8μm to ensure that particles smoothly slide down the conical surface to the cleaning port 15. This embodiment effectively improves the dust removal efficiency and cleaning effect of the centrifugal separation component 1 by optimizing the inner wall structure and surface treatment process of the vertical separator 11. The conical surface design surrounding the cleaning port 15, with a cone angle of 30°-45°, guides the centrifugally separated particles to slide smoothly down the conical surface, preventing particles from accumulating on the inner wall of the vertical separation tank 11. After the inner wall is polished, the surface roughness Ra≤0.8μm, which greatly reduces the friction between the particles and the inner wall, reduces the adsorption of particles on the wall surface, and further ensures that the particles can fall smoothly into the cleaning port 15 for discharge, improving the efficiency of the centrifugal separation component 1, while reducing the difficulty of cleaning and lowering the system maintenance cost.

[0032] In some embodiments, the centrifugal separation assembly 1 further includes a sealing valve 14, which is a pneumatic or electric butterfly valve, sealed and installed at the dust removal port 15. The valve body is connected to the dust removal port 15 by a flange. The valve 14 can be opened and closed independently, with an opening and closing response time ≤2 seconds and a sealing pressure ≥0.6MPa when closed. When open, it is used to discharge collected particulate matter; when closed, it is used to maintain a negative or positive pressure environment within the vertical separation tank 11. This embodiment, by configuring a high-performance sealing valve 14, ensures the stable operation of the centrifugal separation assembly 1 and the overall system sealing performance. The design of the pneumatic or electric butterfly valve enables convenient and rapid opening and closing of the dust removal port 15. The opening and closing response time of ≤2 seconds can promptly discharge the collected particulate matter and avoid dust accumulation affecting the separation effect. The valve body and the dust removal port 15 are connected by flanges and have a sealing pressure of ≥0.6MPa, which effectively ensures the sealing performance of the valve 14 when it is closed, prevents flue gas from leaking from the dust removal port 15, and maintains the required negative or positive pressure environment in the vertical separation tank 11 to ensure the stable operation of the centrifugal separation process. In addition, the valve 14 can be opened and closed independently without affecting the normal operation of the entire flue gas treatment system.

[0033] To better understand this invention, the following is combined with... Figures 1 to 2 The technical solution of the present invention will be described in detail below: The flue gas treatment system consists of a centrifugal separation component 1 and a filter component 2, which work together to achieve graded purification of flue gas and ensure that the treated flue gas meets emission standards. The centrifugal separation component 1 includes a vertical separation tank 11, an inlet pipe 12 and an outlet pipe 13 arranged in a tangential direction, and a dust removal port 15 at the bottom of the tank. In some embodiments, the inner wall of the tank has a conical surface with a cone angle of 30°-45° and is polished. A pneumatic or electric valve 14 that can be opened and closed independently is installed at the dust removal port 15, which can use centrifugal force to efficiently separate large dust particles and discharge them in a timely manner to avoid accumulation and affect efficiency. The filter assembly 2 is a three-stage coaxial sealed docking structure. The first-stage filter unit 22 is a continuous corrugated folded borosilicate glass fiber felt 221 with a density of 0.28 g / cm³ and a thickness of 50 ± 2 mm. The surface is coated with a 1-3 μm nano Al₂O₃ coating, the fiber diameter is 8-12 μm, and the porosity is 85%-90%. The folded structure is optimized to improve filtration performance and stability. The second-stage filter unit 23 uses a 400 cpsi honeycomb ceramic carrier 231, with the pores filled with a specific ratio of Na₂CO₃ and Ca(OH)₂ / Al₂O₃ composite particles. The composite particles are prepared by co-precipitation and have a mesoporous structure on the surface, which can efficiently adsorb acidic gases and heavy metals. The third-stage filter unit 24 is a regular vertical channel array structure made of Mn-ZSM-5 molecular sieve 241 with a specific surface area ≥ 450 m² / g. The surface is loaded with a 0.8 wt% Pt / Rh bimetallic catalyst layer, which is prepared by a specific process and can deeply purify trace harmful substances and achieve catalytic degradation. All components are sealed and connected to effectively prevent flue gas leakage. Each embodiment further improves the purification efficiency, stability and service life of the system by optimizing the structure, parameters and processes.

[0034] The specific embodiments of the present invention described above do not constitute a limitation on the scope of protection of the present invention. Any other corresponding changes and modifications made in accordance with the technical concept of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A flue gas treatment system, characterized in that, The system includes a centrifugal separation assembly and a filtration assembly. The centrifugal separation assembly comprises a vertical separation tank, an inlet pipe, and an outlet pipe. The separation tank has a dust removal port at its bottom. The inlet pipe is sealed and connected to the top side wall of the separation tank along the tangential direction of its circumference. The outlet pipe is sealed and connected to the middle side wall of the separation tank along the tangential direction of its circumference. The filtration assembly comprises a sealed hollow shell, a primary filtration unit, a secondary filtration unit, and a tertiary filtration unit. The inlet end of the shell is sealed and connected to the outlet end of the outlet pipe. An outlet is located at the far end of the shell. The primary filtration unit is made of borosilicate glass fiber with a density of 0.28 g / cm³, a thickness of 50 ± 2 mm, a folding amplitude of 12 mm, and a surface coated with a nano-Al₂O₃ layer. The filter structure is a continuous wave-shaped folded fiber made of felt. The secondary filter unit is a honeycomb carrier filling structure with Na2CO3 particles and Ca(OH)2 / Al2O3 composite particles in the internal pores of a 400cpsi honeycomb ceramic carrier. The tertiary filter unit is a regular vertical channel array molecular sieve filter structure made of Mn-ZSM-5 molecular sieve with a specific surface area ≥450m² / g, pore size 0.55nm, and vertical channel spacing 2mm, with a surface loaded with a 0.8wt%Pt / Rh bimetallic catalyst layer. The primary, secondary, and tertiary filter units are coaxially sealed and connected in sequence along the flue gas flow direction. The outer periphery of each filter unit is sealed and attached to the inner wall of the shell and is fixedly built into the inner cavity of the shell.

2. The flue gas treatment system according to claim 1, characterized in that, The primary filtration unit is a continuous wave-shaped folded fiber filtration structure made of borosilicate glass fiber mat. The glass fiber mat has a density of 0.28 g / cm³, a thickness of 50±2 mm, and a folding amplitude of 12 mm. The folding peaks and valleys are regularly arranged along the flue gas flow direction, and the spacing and depth of the folding peaks and valleys remain consistent throughout the entire filtration unit.

3. The flue gas treatment system according to claim 2, characterized in that, The surface of the borosilicate glass fiber felt is uniformly sprayed with a nano-Al2O3 coating, which covers the entire filtration working surface, including the folded peaks and valleys and the two side slopes. The coating thickness is 1-3μm, which is used to adsorb small particles in flue gas and prevent the fiber felt from being chemically corroded.

4. The flue gas treatment system according to claim 3, characterized in that, The borosilicate glass fiber mat has a fiber diameter of 8-12 μm and a porosity of 85%-90%. The folded structure is formed by continuous indentation molding, and the transition arc radius between the fold peaks and valleys is 2-3 mm to maintain structural stability and filtration uniformity.

5. The flue gas treatment system according to claim 1, characterized in that, The secondary filtration unit includes a honeycomb ceramic carrier and filling particles. The honeycomb ceramic carrier is a 400cpsi honeycomb ceramic carrier with a square pore cross-section and a pore wall thickness of 0.2-0.3mm. The filling particles include Na2CO3 particles and Ca(OH)2 / Al2O3 composite particles, which are mixed in a molar ratio of 1:0.8-1.

2. The particle size is 100-200μm, and the particles are uniformly and tightly filled in the pores of the carrier, with a filling density of 0.6-0.8g / cm³.

6. The flue gas treatment system according to claim 5, characterized in that, The Ca(OH)2 / Al2O3 composite particles have a mass ratio of Ca(OH)2 to Al2O3 of 1:2-3 and are prepared by co-precipitation. The particle surface has a mesoporous structure with a mesopore diameter of 5-10 nm, which is used to enhance the adsorption capacity for acidic gases and heavy metals.

7. The flue gas treatment system according to claim 1, characterized in that, The three-stage filtration unit is a regular vertical channel array molecular sieve filtration structure made of Mn-ZSM-5 molecular sieve. The molecular sieve has a specific surface area ≥450m² / g, a pore size of 0.55nm, a vertical channel spacing of 2mm, a channel diameter of 0.5-0.8mm, a channel wall thickness of 0.3-0.5mm, and a metal catalyst layer uniformly loaded on the surface and inner wall of the channel with a catalyst layer thickness of 0.5-1μm.

8. The flue gas treatment system according to claim 7, characterized in that, The metal catalyst layer is a Pt / Rh bimetallic catalyst layer with a Pt to Rh mass ratio of 2:1-3:1 and a loading of 0.8wt%. The catalyst layer is uniformly attached to the surface of the molecular sieve and the inner wall of the channel by impregnation and is calcined at 500-600℃ to form stable catalytic active sites.

9. The flue gas treatment system according to claim 1, characterized in that, The inner wall of the separation tank has a conical surface surrounding the cleaning port, with a cone angle of 30°-45°, converging from top to bottom towards the center of the cleaning port. The inner wall is polished to a surface roughness Ra≤0.8μm to ensure that particles slide smoothly down the conical surface to the cleaning port.

10. The flue gas treatment system according to claim 1, characterized in that, The centrifugal separation assembly also includes a sealing valve, which is a pneumatic or electric butterfly valve, sealed and installed at the ash removal port. The valve body is connected to the ash removal port flange. The valve can be opened and closed independently, with an opening and closing response time of ≤2 seconds and a sealing pressure of ≥0.6MPa when closed. When opened, it is used to discharge the collected particulate matter, and when closed, it is used to maintain a negative or positive pressure environment in the separation tank.

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