A desulfurization slurry oxidation system

Abstract

The utility model provides a kind of desulfurization slurry oxidation system, belong to desulfurization slurry oxidation treatment technical field, comprising: absorption tower, its lateral wall is equipped with limestone slurry inlet and sulfur-containing flue gas inlet;Multiple toroidal pipes, multiple toroidal pipes concentrically set, multiple gas outlets are provided on each toroidal pipe, multiple toroidal pipes are located in slurry pool in absorption tower bottom;Fan, its outlet is communicated main gas supply pipe;Each toroidal pipe is communicated with main gas supply pipe by a branch pipe;And multiple slurry circulating pumps, one end of each slurry circulating pump is communicated with slurry pool, and the other end is communicated with the spray layer inside absorption tower;Sulfur-containing flue gas inlet is located in the lower side of spray layer.The utility model's set "high -efficient energy -conserving gas supply, strengthen gas-liquid mass transfer, intelligent dynamic regulation" in one's body based on magnetic suspension oxidation fan and mass transfer intensification device's slurry oxidation system can satisfy industrial enterprise ultra-low emission, double needs of cost reduction and efficiency improvement, with significant engineering application value and market prospect.

Description

Technical Field

[0001] This utility model belongs to the field of desulfurization slurry oxidation treatment technology, and more specifically, it relates to a desulfurization slurry oxidation system. Background Technology

[0002] Driven by both the "dual carbon" goals and ultra-low emission policies, the flue gas desulfurization efficiency and operational economy of industrial boilers in industries such as thermal power units, steel, and chemicals have become core demands for enterprises to achieve environmental compliance and cost control. Limestone-gypsum wet desulfurization (WFGD) has become the mainstream desulfurization technology both domestically and internationally due to its high desulfurization efficiency and mature, stable process. Currently, the application rate of WFGD in domestic thermal power units is extremely high, and its application coverage in the industrial boiler sector has also increased significantly. Its core reaction mechanism is as follows: after SO2-containing flue gas enters the absorption tower, it comes into full contact with the sprayed limestone (CaCO3) slurry, generating calcium sulfite (CaSO3) through two steps: "SO2 + H2O → H2SO3" and "H2SO3 + CaCO3 → CaSO3 + CO2 + H2O". Subsequently, air is blown into the slurry pool at the bottom of the absorption tower to oxidize CaSO3 into calcium sulfate dihydrate (CaSO42H2O, i.e., gypsum), and finally, the gypsum is recycled through a dehydration system.

[0003] However, the existing WFGD slurry oxidation system has gradually revealed prominent problems in its long-term operation that are incompatible with ultra-low emission requirements and energy conservation and consumption reduction goals. These problems are specifically reflected in the following aspects: Traditional fans have significant energy efficiency bottlenecks: The current mainstream centrifugal or Roots oxidation fans have generally low operating efficiency due to problems such as mechanical friction and airflow loss. The annual power consumption of a single fan is large, and the energy cost accounts for a high proportion of the total energy consumption of the desulfurization system. High equipment operation and maintenance costs: Traditional wind turbines require regular replacement of lubricating oil and maintenance of bearings, and the vibration and noise during operation exceed the standard (noise is usually >95dB), which not only increases the labor intensity of operation and maintenance personnel, but also requires additional investment in vibration reduction and noise reduction equipment, resulting in high annual operation and maintenance costs; Insufficient flexibility in gas supply regulation: Existing systems mostly adopt the "fixed speed operation + valve regulation" mode, which cannot dynamically adjust the air volume according to the unit load and the CaSO3 concentration in the slurry, resulting in excessive air volume at low load and insufficient dissolved oxygen at high load, and poor adaptability to operating conditions. Low gas-liquid mass transfer efficiency: Traditional aeration devices mostly use large-aperture aeration discs, which generate large-diameter bubbles. These bubbles rise quickly in the slurry with short residence times, resulting in a small gas-liquid contact surface area and low oxygen utilization, thus limiting the oxidation reaction rate. Deterioration of by-product gypsum quality: Under localized oxygen-deficient conditions, unoxidized CaSO3 in the slurry easily generates by-product salts such as calcium sulfite hemihydrate (CaSO3¹ / ²H₂O). At the same time, excess limestone that has not fully reacted will leave behind CaCO₃, causing the purity of by-product gypsum to be lower than the requirements for building material recycling. This not only prevents resource utilization but also requires solid waste disposal, increasing environmental protection costs.

[0004] Based on the aforementioned industry pain points, it is necessary to develop an energy-saving and efficiency-enhancing desulfurization slurry oxidation system to address at least one of the shortcomings of existing technologies and meet the dual needs of industrial enterprises for ultra-low emissions, cost reduction, and efficiency improvement. Utility Model Content

[0005] The purpose of this utility model is to provide a desulfurization slurry oxidation system to effectively solve at least one of the defects of the existing technology, meet the dual needs of industrial enterprises for ultra-low emissions and cost reduction and efficiency improvement, and has significant engineering application value and market promotion prospects.

[0006] To achieve the above objectives, this utility model provides a desulfurization slurry oxidation system, comprising: The absorption tower has a limestone slurry inlet and a sulfur-containing flue gas inlet on its side wall; Multiple ring pipes are arranged concentrically, and each ring pipe is provided with multiple air outlets. The multiple ring pipes are located in the slurry pool at the bottom of the absorption tower. A fan, the outlet of which is connected to the main air supply pipe; each of the said annular pipes is connected to the main air supply pipe via a branch pipe; and... Multiple slurry circulation pumps are provided, with one end of each pump connected to the slurry pool via a slurry circulation pipe, and the other end connected to the spray layer inside the absorption tower via the same slurry circulation pipe; the sulfur-containing flue gas inlet is located below the spray layer.

[0007] Furthermore, the fan is a magnetic levitation oxidation fan, and the fan uses a variable frequency permanent magnet motor, which is speed-regulated by a variable frequency controller.

[0008] Furthermore, the slurry tank is equipped with a dissolved oxygen sensor, a pH sensor, and a sulfite concentration detector.

[0009] Furthermore, it also includes a PLC control system, which is electrically connected to the dissolved oxygen sensor, the pH sensor, the sulfite concentration detector, the frequency converter of the blower, the slurry circulation pump, and the limestone slurry inlet regulating valve; The PLC control system controls the frequency converter based on the dissolved oxygen concentration value received from the dissolved oxygen sensor and the concentration data from the sulfite concentration detector, so as to control the frequency of the fan. The PLC control system controls the opening degree of the limestone slurry inlet regulating valve based on the pH value received from the pH sensor. The PLC control system controls the number of operating slurry circulation pumps based on the sulfur dioxide concentration and flue gas volume at the sulfur-containing flue gas inlet.

[0010] Furthermore, multiple dissolved oxygen sensors are provided, with one sensor located on one side of each of the ring tubes.

[0011] Furthermore, the multiple ring pipes are arranged at equal intervals, and the diameter of the air outlet is 5-15mm.

[0012] Furthermore, the plurality of air outlets are evenly distributed along the circumference of each of the annular tubes.

[0013] Furthermore, the diameter and spacing of the air outlet holes on the multiple ring pipes are all the same.

[0014] Furthermore, it also includes a ring tube fixing bracket for supporting and fixing the plurality of said ring tubes.

[0015] Furthermore, the ring pipe fixing support is a steel beam installed at the bottom of the absorption tower.

[0016] Compared with the prior art, the present invention has the following technical effects: This utility model discloses a desulfurization slurry oxidation system. By setting multiple ring-pipe aeration openings in the slurry pool at the bottom of the absorption tower, it avoids the "dense in the center and sparse at the edge" problem of single-ring-pipe aeration, achieving a more uniform distribution of oxygen throughout the slurry pool and effectively eliminating aeration "dead zones." By setting up a slurry circulation pump and adopting a "bottom pumping + top spraying" arrangement, the slurry is drawn from the bottom of the pool and transported to the upper spray layer, forming a circulating flow field covering the entire pool. This flow field, on the one hand, prevents CaSO3 particles from settling at the bottom of the pool and clogging the ring-pipe openings; on the other hand, it strongly disturbs the rising microbubbles, prolonging the residence time of the bubbles in the slurry. This invention promotes thorough mixing of slurry and air bubbles, resulting in a uniform distribution of CaSO3 concentration throughout the tank, significantly improving the uniformity and rate of the oxidation reaction. The combination of multi-ring pipe perforated aeration and a full-tank circulating flow field in this invention greatly increases the gas-liquid contact surface area, prolongs bubble residence time, significantly improves oxygen utilization, and accelerates the oxidation reaction rate. Even under full-load operation, the oxidation efficiency can be stably maintained above 98%. Furthermore, the stable slurry concentration and uniform flow field effectively suppress the formation of by-product salts, improve gypsum quality, and increase the purity of by-product gypsum to meet building material recycling standards. This allows for resource utilization as a building material raw material, reducing solid waste disposal and lowering environmental costs. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the structure of a desulfurization slurry oxidation system provided in an embodiment of the present invention; Figure 2 for Figure 1 A top view of the central ring pipe; Figure 3 This is a schematic diagram of the ring tube opening structure provided in an embodiment of the present utility model. The opening is located on the lower side of the ring tube. Figure 4 A flowchart illustrating the control of the air volume of a magnetic levitation oxidation fan by a PLC control system provided in this embodiment of the utility model; Figure 5 A flowchart illustrating the number of slurry circulation pumps controlled by a PLC control system provided in this embodiment of the invention.

[0019] The following are the labeling elements in the figure: 1. Absorption tower; 2. Loop pipe; 3. Fan; 4. Main gas supply pipe; 5. Branch pipe; 6. Slurry circulation pump; 7. Slurry circulation pipe; 8. Dissolved oxygen sensor; 9. pH sensor; 10. Sulfite concentration detector; 11. PLC control system; 12. Loop pipe fixing bracket; 101. Limestone slurry inlet; 102. Sulfur-containing flue gas inlet; 103. Slurry tank; 104. Spray layer; 201. Gas outlet. Detailed Implementation

[0020] To make the technical problems, technical solutions, and beneficial effects of this utility model clearer, the present utility model 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 of the present utility model and are not intended to limit the present utility model.

[0021] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0022] It should be understood that the terms "length", "upper", "lower", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0023] The terminology used in the embodiments of this utility model is for the purpose of describing particular embodiments only and is not intended to be limiting of the utility model. The singular forms “a,” “the,” and “the” used in the embodiments of this utility model and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0024] In response to the core defects of existing slurry oxidation systems, this utility model embodiment needs to focus on breaking through the following four key technical issues: (1) How to break through the energy efficiency bottleneck of traditional fans, and achieve a significant reduction in the energy consumption of the oxidation system through a frictionless, high-precision adjustable air supply device, while reducing operation and maintenance costs; (2) How to optimize the aeration structure and flow field design to solve the problems of uneven bubble distribution and short residence time, significantly increase the gas-liquid contact surface area, and improve oxygen utilization; (3) How to extend the contact time between bubbles and slurry, improve the oxidation reaction rate, and ensure stable oxidation efficiency under high load conditions without increasing system complexity and floor space, through a simple and reliable mass transfer enhancement method; (4) How to establish a closed-loop intelligent control system to achieve dynamic matching of air supply, dissolved oxygen concentration, and slurry composition, avoid local hypoxia or excessive air volume, reduce the generation of by-product salts, and improve the purity of by-product gypsum to meet the standards for building material recycling.

[0025] To address at least one of the shortcomings of existing slurry oxidation systems, this invention provides a desulfurization slurry oxidation system. Please refer to... Figures 1-5 The present invention will now describe a desulfurization slurry oxidation system provided in an embodiment of the present invention.

[0026] In one embodiment of this utility model, a desulfurization slurry oxidation system includes an absorption tower 1, multiple loop pipes 2, a blower 3, and multiple slurry circulation pumps 6. The side wall of the absorption tower 1 is provided with a limestone slurry inlet 101 and a sulfur-containing flue gas inlet 102. The multiple loop pipes 2 are arranged concentrically, and each loop pipe 2 is provided with multiple air outlets 201. The multiple loop pipes 2 are located in the slurry pool 103 at the bottom of the absorption tower 1. The outlet of the blower 3 is connected to the main air supply pipe 4. Each loop pipe 2 is connected to the main air supply pipe 4 through a branch pipe 5. One end of each slurry circulation pump 6 is connected to the slurry pool 103 through a slurry circulation pipe 7, and the other end is connected to the spray layer 104 inside the absorption tower 1 through the slurry circulation pipe 7. The sulfur-containing flue gas inlet 102 is located on the lower side of the spray layer 104.

[0027] In this embodiment, the limestone slurry inlet 101 is connected to the limestone slurry supply pipeline, and a limestone slurry inlet regulating valve is installed on the limestone slurry supply pipeline to regulate the flow rate of limestone slurry entering the absorption tower 1. The sulfur-containing flue gas inlet 102 is connected to the sulfur-containing flue gas pipeline, through which sulfur-containing flue gas is input into the absorption tower 1. A CEMS device is installed on the sulfur-containing flue gas pipeline to collect real-time data on sulfur dioxide (SO2) concentration and flue gas volume at the sulfur-containing flue gas inlet 102. An outlet flue gas pipeline is installed at the top of the absorption tower 1, and a CEMS device is also installed on the outlet flue gas pipeline to collect real-time data on the sulfur dioxide concentration of the outlet flue gas. Multiple ring pipes 2 can be supported and fixed by ring pipe fixing brackets 12, which can be steel beams installed at the bottom of the absorption tower 1.

[0028] In this embodiment, the absorption tower 1 is equipped with a multi-ring perforated aeration device. Specifically, several ring pipes 2 are arranged in a concentric ring pattern at the bottom of the slurry tank 103 of the absorption tower 1 (the number of ring pipes 2 is determined according to the diameter of the slurry tank 103, typically 2-5 rings). The ring pipes 2 can be made of acid and alkali resistant metal. Preferably, the spacing between adjacent ring pipes 2 is uniform (ensuring complete coverage of the entire tank without dead corners), i.e., the ring pipes 2 are evenly spaced. Each ring pipe 2 has uniformly spaced air outlet holes 201 (aeration holes) along its circumference, with the hole diameter precisely controlled between 5-15 mm, and the hole spacing adapted to the diameter of the ring pipe 2. Preferably, the hole diameter and hole spacing of the air outlet holes 201 on multiple ring pipes 2 are the same, so that the air output per unit area within the slurry tank 103 of multiple ring pipes 2 remains consistent.

[0029] In this embodiment, several ring pipes 2 are connected to the main air supply pipe 4 via branch pipes 5. The main air supply pipe 4 is connected to the outlet of the blower 3. The airflow is distributed to each ring pipe 2 through the main air supply pipe 4, and then ejected through the uniformly opened air outlets 201 on the ring pipes 2, forming microbubbles with a diameter of 1-3 mm. This design of multiple ring pipes 2 + uniformly opened air outlets 201 in this embodiment can control the bubble parameters by precisely controlling the opening diameter and the spacing between the holes, avoiding the problem of "dense in the center and sparse at the edge" in the existing single ring pipe aeration, realizing the uniform distribution of oxygen throughout the slurry tank 103, and effectively eliminating the aeration "dead zone".

[0030] In this embodiment, multiple slurry circulation pumps 6 can be used to enhance slurry agitation. This embodiment adopts a "bottom pumping + top spraying" arrangement, which uniformly extracts the slurry from different areas at the bottom of the tank and transports it to the spray layer 104 above the slurry tank 103, forming an optimized circulating flow field covering the entire tank. This optimized flow field can, on the one hand, prevent CaSO3 particles from settling at the bottom of the tank and prevent clogging of the ring pipe openings, and on the other hand, it can strongly disturb the rising microbubbles, prolong the residence time of the bubbles in the slurry, and at the same time promote the full mixing of slurry and bubbles, achieving efficient gas-liquid mass transfer, making the CaSO3 concentration uniform throughout the tank, and significantly improving the uniformity and reaction rate of the oxidation reaction.

[0031] This embodiment of the invention combines multi-ring pipe perforated aeration with a full-pool circulating flow field, which significantly increases the gas-liquid contact surface area, prolongs bubble residence time, significantly improves oxygen utilization, and accelerates the oxidation reaction rate. Even under full-load operation, the oxidation efficiency can still be stably maintained at over 98%. Furthermore, the stable slurry concentration and uniform flow field can effectively suppress the formation of by-product salts, improve gypsum quality, and increase the purity of by-product gypsum to meet the standards for building material recycling. It can be used as a resource for building material raw materials, reducing the amount of solid waste disposal and lowering environmental protection costs.

[0032] Furthermore, fan 3 is a magnetic levitation oxidation fan, employing a variable frequency permanent magnet motor. The speed of the variable frequency permanent magnet motor is controlled by a variable frequency controller. This embodiment uses a permanent magnet synchronous magnetic levitation oxidation fan to replace the traditional centrifugal / Roots blower. The magnetic levitation bearing achieves contactless rotor support, reducing mechanical friction loss to near zero and significantly improving fan operating efficiency. The variable frequency permanent magnet motor offers a wide speed adjustment range, enabling stepless adjustment of the air supply volume, and the air pressure output range adapts to the needs of desulfurization towers of different sizes. The magnetic levitation bearing requires no lubrication, eliminating the leakage and pollution risks of traditional fan lubrication systems, while also avoiding bearing wear problems, extending the equipment's design life. Operating noise is ≤80dB (complies with the "Emission Standard for Industrial Enterprises Boundary Environmental Noise" GB12348-2022 and occupational health requirements), eliminating the need for additional noise reduction equipment. Moreover, the magnetic levitation oxidation fan system has no vulnerable parts, enabling continuous and stable operation for over 300 days, reducing unplanned downtime and demonstrating strong operational stability.

[0033] This embodiment ensures uniform bubble generation at each opening by precisely controlling the aperture and spacing of the openings on the ring pipe 2, combined with the stable air pressure output of the magnetic levitation fan. This reduces the bubble rising speed, significantly increases the gas-liquid contact surface area, and greatly improves oxygen utilization.

[0034] Furthermore, a dissolved oxygen sensor 8, a pH sensor 9, and a sulfite concentration detector 10 are installed in the slurry tank 103. In this embodiment, the air supply of the blower 3, the flow rate of the limestone slurry, and the number of slurry circulation pumps 6 in operation can be adjusted based on the detection data of the dissolved oxygen sensor 8, pH sensor 9, and sulfite concentration detector 10, as well as the sulfur dioxide concentration data monitored by the CEMS at the flue gas inlet and outlet, so as to ensure the normal operation of desulfurization in the absorption tower 1.

[0035] Furthermore, the desulfurization slurry oxidation system of this embodiment also includes a PLC control system 11. The PLC control system 11 is electrically connected to the dissolved oxygen sensor 8, pH sensor 9, sulfite concentration detector 10, frequency converter of the blower 3, slurry circulation pump 6, and limestone slurry inlet regulating valve. The PLC control system 11 controls the frequency converter of the blower 3 according to the dissolved oxygen concentration value received from the dissolved oxygen sensor 8 and the concentration data from the sulfite concentration detector 10, thereby controlling the operating frequency of the blower 3. The PLC control system 11 controls the opening degree of the limestone slurry inlet regulating valve according to the pH value received from the pH sensor 9. The PLC control system 11 adjusts the number of slurry circulation pumps 6 in operation based on the sulfur dioxide concentration data monitored by the CEMS at the flue gas inlet and outlet. In addition, the frequency converter of the blower in this embodiment can also be linked with the desulfurization system DCS, and can automatically adjust the motor speed according to the dissolved oxygen concentration of the slurry and the unit load signal to achieve "on-demand gas supply" and avoid energy waste at low loads.

[0036] In this embodiment, in the oxidation fan control strategy of the desulfurization system, the sulfite concentration detected by the sulfite concentration detector 10 and the dissolved oxygen concentration detected by the dissolved oxygen sensor 8 form a master-slave collaborative closed-loop system. This system uses the sulfite concentration as the master control signal, directly ensuring the core process objective of oxidation efficiency by adjusting the frequency of the fan 3, thus achieving energy-saving operation. Simultaneously, it uses the dissolved oxygen concentration as a key auxiliary constraint signal, setting a safety lower limit to prevent slurry "oxygen deficiency" and ensure the basic environment for the oxidation reaction. The final output of the PLC control system 11 is automatically adjusted based on the sulfite concentration and is forcibly controlled by the safety verification of the dissolved oxygen concentration. Therefore, under the premise of meeting process requirements, precise and energy-saving control of the oxidation air volume is achieved. The control process is as follows: Figure 4 As shown.

[0037] The PLC control system 11, based on real-time sulfur dioxide concentration and flue gas volume data collected by the CEMS on the inlet sulfur-containing flue gas pipeline, calculates the real-time SO2 load and performs graded control on the number of operating slurry circulation pumps 6. The control process is as follows: Figure 5 As shown. To achieve balanced use of the pump set equipment, the PLC control system 11 automatically accumulates the running time of each slurry circulation pump 6. When performing start-up and shutdown operations, the PLC control system 11 will prioritize starting the pump with the shortest accumulated running time or stopping the pump with the longest running time, thereby effectively distributing wear and extending the overall service life of the pump set. In the control structure, the SO2 load at the sulfur-containing flue gas inlet 102 serves as a feedforward signal to achieve rapid response and coarse adjustment of the slurry circulation pump 6; while the SO2 concentration at the outlet of the top of the absorption tower 1 serves as the final process target for closed-loop fine-tuning and verification of the system. If the outlet SO2 concentration is still close to the emission limit when all pumps are in operation, the PLC control system 11 will trigger a high-level alarm and can also link to adjust auxiliary measures such as the limestone slurry supply to further enhance desulfurization efficiency and ensure continuous compliance with emission standards.

[0038] Generally, the higher the sulfur dioxide load, the more slurry circulation pumps 6 are in operation. For example, in one embodiment, when the sulfur dioxide load reaches 5000 kg / h or more, the PLC control system 11 controls 3 slurry circulation pumps 6 to operate; when the sulfur dioxide load reaches 6000 kg / h or more, the PLC control system 11 controls 4 slurry circulation pumps 6 to operate; when the sulfur dioxide load reaches 7000 kg / h or more, the PLC control system 11 controls 5 slurry circulation pumps 6 to operate; and when the sulfur dioxide load reaches 8000 kg / h or more, the PLC control system 11 controls 6 slurry circulation pumps 6 to operate.

[0039] Specifically, multiple dissolved oxygen (DO) sensors 8 (measurement range 0–20 mg / L, accuracy ±0.1 mg / L), pH sensors 9 (measurement range 2.0–12.0, accuracy ±0.05), and sulfite concentration detectors 10 can be arranged in the slurry tank 103. A dissolved oxygen sensor 8 is provided on one side near each loop pipe 2, and the sensor data is transmitted to the PLC control system 11 in real time. In one embodiment, when the DO concentration is <2 mg / L, the PLC control system 11 automatically increases the speed of the magnetic levitation fan to increase the air supply until the DO concentration rises back to 2–6 mg / L; when the DO concentration is >6 mg / L, the PLC control system 11 reduces the fan speed to decrease the air supply; when the pH is <4.5, the PLC control system 11 controls the opening of the limestone slurry inlet regulating valve of the limestone slurry supply pipeline to increase the amount of limestone slurry added, preventing the slurry from being too acidic and corroding the equipment; when the pH is >6.0, the PLC control system 11 controls the opening of the limestone slurry inlet regulating valve to decrease the amount of limestone added, avoiding excessive CaCO3 residue; based on the CaSO3 concentration data (sulfite concentration detector 10), the PLC control system 11 dynamically adjusts the frequency of the magnetic levitation oxidation fan to ensure timely oxidation of CaSO3 and avoid the formation of by-product salts.

[0040] In one embodiment, when the sulfite concentration reaches 0.15 mmol / L or higher, the frequency of the magnetic levitation oxidation fan can be adjusted to 20% of the design rating; when the sulfite concentration reaches 1 mmol / L or higher, the frequency of the magnetic levitation oxidation fan can be adjusted to 60% of the design rating; and when the sulfite concentration reaches 5 mmol / L or higher, the frequency of the magnetic levitation oxidation fan can be adjusted to 100% of the design rating.

[0041] This embodiment achieves adaptive adjustment under all operating conditions through multi-parameter closed-loop control, adapting to unit operation with 30%-100% variable load. The device has a simple structure, and all components can be retrofitted and installed on the basis of existing desulfurization systems. The retrofit cycle is short, the investment payback period is short, and it can be widely used in WFGD systems of different industries, with strong market adaptability.

[0042] The desulfurization slurry oxidation system in this embodiment uses a magnetic levitation fan, which greatly improves efficiency. Combined with the PLC control system 11, it realizes intelligent on-demand air supply, and the overall power consumption of the system is significantly reduced. At the same time, the oil-free and long-life characteristics greatly reduce the annual maintenance cost, and have significant energy-saving and consumption-reducing advantages. It is also intelligent and adaptable.

[0043] Overall, the energy-saving and efficiency-enhancing desulfurization slurry oxidation system developed in this embodiment, based on a magnetic levitation oxidation fan and a mass transfer enhancement device, integrates "magnetic levitation high-efficiency air supply + multi-ring pipe perforated aeration + flow field optimization + intelligent control" to construct an energy-saving and efficiency-enhancing desulfurization slurry oxidation system. This system, which integrates "high-efficiency energy-saving air supply, enhanced gas-liquid mass transfer, and intelligent dynamic adjustment," has significant advantages in energy saving, efficiency, quality, operation and maintenance, and adaptability. It can effectively solve the defects of existing technologies and meet the dual needs of industrial enterprises for ultra-low emissions and cost reduction and efficiency improvement.

[0044] The following specific application example illustrates the advantages of a desulfurization slurry oxidation system according to an embodiment of this utility model: Application example: Taking the desulfurization tower (absorption tower) of a thermal power plant as an application scenario.

[0045] The effective volume of the desulfurization tower slurry tank 103 is approximately 1200 m³, designed to treat 1.1 million Nm³ / h of sulfur-containing flue gas. The original system used Roots blowers for aeration, which suffered from high energy consumption and low gypsum purity. The modification adopts the technical solution of this embodiment. This modification uses the multi-ring pipe perforated aeration system of this embodiment. The core of the system consists of three sets of concentric ring pipes 2 (aeration core), a main air supply pipe 4, a magnetic levitation oxidation blower, a frequency converter, a slurry circulation pump 6, a dissolved oxygen sensor 8, and a PLC control system 11. Multi-ring design: All three ring pipes 2 are made of duplex stainless steel and are arranged in concentric circles at the bottom of the slurry tank 103 (5m from the bottom of the tank); the outer ring pipe has a diameter of 8m, the middle ring pipe has a diameter of 5m, the inner ring pipe has a diameter of 2m, and the distance between adjacent ring pipes is 1.5m; each ring pipe 2 has evenly distributed air outlet holes 201 (hole diameter 9mm), with 80 holes in the outer ring pipe (hole spacing 314mm), 50 holes in the middle ring pipe (hole spacing 314mm), and 20 holes in the inner ring pipe (hole spacing 314mm), ensuring consistent air output per unit area, uniform oxidation of the slurry tank in the tower, and no dead corners; Gas supply connection: The three sets of ring pipes 2 are connected to the main gas supply pipe 4 through a branch pipe 5. Valves are installed on the branch pipes 5 to adjust the gas supply of each ring pipe 2 individually; the main gas supply pipe 4 is connected to the outlet of the magnetic levitation oxidation blower. Other equipment: Magnetic levitation oxidation blower with variable frequency controller; 5 slurry circulation pumps (6 units) arranged along the bottom of the pool; 3 dissolved oxygen sensors (8 units) installed (e.g., Figure 2 As shown), two sets of pH sensors 9 are installed, both connected to the PLC control system 11 and networked with the power plant's desulfurization DCS system.

[0046] The installation process strictly follows industrial equipment installation standards, and the specific steps are as follows: Step 1, System shutdown preparation: shut down the original oxidation blower and slurry circulation system, drain the slurry in slurry tank 103, use a high-pressure water gun to clean the sludge and residual gypsum at the bottom of the tank, and remove the original oxidation air branch pipe device; The second step is the installation of the multi-ring pipe 2: First, fix the ring pipe fixing bracket 12 at the design position on the bottom of the pool, then hoist the outer ring pipe, middle ring pipe and inner ring pipe in sequence, and adjust the levelness (deviation ≤2mm / m) to ensure that the three sets of ring pipes 2 are concentric; weld the ring pipe 2 to the branch pipe 5, and connect the branch pipe 5 to the main air supply pipe 4 with a flange; use a special tool to grind the opening smooth to avoid burrs that cause uneven air bubbles. Step 3, installation of fan 3 and pipeline: Fix the magnetic levitation fan on the reserved equipment foundation (foundation flatness deviation ≤1mm), connect the main air supply pipe 4 (install a 10μm precision air filter at the inlet and a check valve and pressure gauge at the outlet); conduct an airtightness test on the entire air supply pipeline (test pressure 0.2MPa, pressure held for 30min without leakage). Step 4, Installation of slurry circulation pump 6 and sensor: Fix slurry circulation pump 6 on the pre-set foundation at the bottom of the tank, connect the inlet and outlet pipelines and install butterfly valves; insert the sensor probe 1.2m below the slurry operating level to ensure that the detection point covers the multi-loop aeration area, and run the cable through a CPVC protective pipe into the control room; Step 5, PLC control system 11 debugging: Power-on test to ensure normal power supply to all equipment; set dissolved oxygen control threshold (2-6 mg / L) and pH control range (4.5-6.0) in the PLC control cabinet; start the blower 3 for no-load test run; adjust the valves on each branch pipe 5; confirm the uniform distribution of bubbles at the openings of the three sets of ring pipes 2 by visual observation (or by using a bubble detector); simulate 30%, 70%, and 100% unit load conditions; debug the linkage logic between the speed of blower 3 and the number of slurry circulation pumps 6 in operation to ensure automatic alarm and adjustment when parameters are abnormal.

[0047] Actual performance: After installation and commissioning in the desulfurization tower of a 300MW thermal power unit, the system operated continuously for 12 months, with stable and excellent performance indicators, fully verifying the feasibility and superiority of the technical solution. Energy saving effect: The magnetic levitation fan has an operating efficiency of 88%, and with the on-demand air supply logic, it saves an average of 150,000 kWh of electricity per year; calculated based on an industrial electricity price of 0.65 yuan / kWh, it saves 97,000 yuan in electricity costs per year; the fan does not require lubrication oil replacement, reducing annual maintenance consumable costs by 23,000 yuan, and reducing the workload of maintenance personnel by 60%; Gas-liquid mass transfer and oxidation efficiency: Three sets of loop pipes with two openings for aeration achieve uniform oxygen distribution throughout the pool, and the dissolved oxygen concentration in the slurry is stably maintained at 3.5-5.0 mg / L. The oxidation efficiency is maintained above 98% for a long time. Even when the unit is at 100% full load and the SO2 inlet concentration is 4000 mg / Nm, it can still ensure complete oxidation of CaSO3. Improved gypsum quality: Stable oxygen supply and uniform flow field significantly reduce the generation of by-product salts (CaSO31 / 2H2O, CaCO3), increasing the purity of by-product gypsum from 88% before the renovation to 95.2%, with an attached water content of ≤10%, fully meeting the requirements for building gypsum products raw materials in GB / T5484-2012 "Flue Gas Desulfurization Gypsum". Operational stability: The measured noise level of the blower at the plant boundary is 78dB (compliant with environmental standards), and there has been no record of fault-based shutdown within 12 months; the control system is highly responsive—when the unit load suddenly increases from 50% to 100%, the dissolved oxygen concentration drops to 2.2mg / L, the blower speed automatically increases within 15 seconds, and the dissolved oxygen concentration recovers to 3.8mg / L within 30 seconds, allowing for stable operation without manual intervention; The multi-ring pipe design allows for flexible adjustment of the number and diameter of slurry tanks of different sizes, providing direct reference for the transformation of desulfurization systems in similar thermal power units and steel sintering machines, and has significant market promotion value.

[0048] The above embodiments only illustrate several implementation methods of this utility model, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of this utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

Claims

1. A desulfurization slurry oxidation system, characterized in that, include: The absorption tower has a limestone slurry inlet and a sulfur-containing flue gas inlet on its side wall; Multiple ring pipes are arranged concentrically, and each ring pipe is provided with multiple air outlets. The multiple ring pipes are located in the slurry pool at the bottom of the absorption tower. A fan, the outlet of which is connected to the main air supply pipe; each of the said annular pipes is connected to the main air supply pipe via a branch pipe; and... Multiple slurry circulation pumps are provided, with one end of each pump connected to the slurry pool via a slurry circulation pipe, and the other end connected to the spray layer inside the absorption tower via the same slurry circulation pipe; the sulfur-containing flue gas inlet is located below the spray layer.

2. The desulfurization slurry oxidation system as described in claim 1, characterized in that, The fan is a magnetic levitation oxidation fan, and the fan uses a variable frequency permanent magnet motor. The variable frequency permanent magnet motor achieves speed regulation through the control of a variable frequency controller.

3. The desulfurization slurry oxidation system as described in claim 2, characterized in that, The slurry tank is equipped with a dissolved oxygen sensor, a pH sensor, and a sulfite concentration detector.

4. The desulfurization slurry oxidation system as described in claim 3, characterized in that, It also includes a PLC control system, which is electrically connected to the dissolved oxygen sensor, the pH sensor, the sulfite concentration detector, the frequency converter of the blower, the slurry circulation pump, and the limestone slurry inlet regulating valve; The PLC control system controls the frequency converter based on the dissolved oxygen concentration value received from the dissolved oxygen sensor and the concentration data from the sulfite concentration detector, so as to control the frequency of the fan. The PLC control system controls the opening degree of the limestone slurry inlet regulating valve based on the pH value received from the pH sensor. The PLC control system controls the number of operating slurry circulation pumps based on the sulfur dioxide concentration and flue gas volume at the sulfur-containing flue gas inlet.

5. The desulfurization slurry oxidation system as described in claim 4, characterized in that, The dissolved oxygen sensor is provided in multiple ways, with one of the dissolved oxygen sensors located on one side near each of the ring tubes.

6. The desulfurization slurry oxidation system as described in claim 4, characterized in that, Multiple ring pipes are arranged at equal intervals, and the diameter of the air outlet is 5-15mm.

7. The desulfurization slurry oxidation system as described in claim 6, characterized in that, The multiple air outlets are evenly distributed along the circumference of each of the annular pipes.

8. The desulfurization slurry oxidation system as described in claim 7, characterized in that, The diameter and spacing of the air outlet holes on the multiple ring pipes are all the same.

9. A desulfurization slurry oxidation system according to any one of claims 1-8, characterized in that, It also includes a ring tube fixing bracket for supporting and fixing the plurality of the ring tubes.

10. A desulfurization slurry oxidation system as described in claim 9, characterized in that, The ring pipe fixing support is a steel beam installed at the bottom of the absorption tower.

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