A high-efficiency low-resistance anti-clogging graded limestone-gypsum wet desulfurization method

Abstract

The application discloses a kind of high efficiency low resistance anti-jamming hierarchical limestone-gypsum wet desulfurization method, belong to industrial flue gas purification environmental protection technical field.Aiming at the problems such as low limestone utilization rate, poor gypsum purity and slurry easy to scale deposition in tower in existing scene, the application constructs hierarchical atomization spraying, zoned accurate oxidation, slurry gradient activation filtration, integrated architecture of working condition self-adaptive intelligent control, system includes flue gas pretreatment, desulfurization absorption tower, slurry circulation activation, zoned oxidation aeration, gypsum dehydration refining and intelligent control module.The application adopts double-layer staggered differential spraying to match gradient particle size slurry grading feed, desulfurization efficiency is stable ≥99%, limestone utilization rate is increased by 15%~20%, comprehensive energy consumption is reduced by more than 12%, gypsum purity is ≥95%, water content is ≤8%, suitable for flue gas ultra-low purification scene such as thermal power generating unit, industrial kiln and the like.

Description

Technical Field

[0001] This invention belongs to the field of industrial flue gas desulfurization and purification and environmental protection and energy saving technology. Specifically, it relates to a high-efficiency, low-resistance, and anti-clogging graded limestone-gypsum wet desulfurization method, which is applicable to ultra-low sulfur dioxide purification treatment scenarios for various industrial flue gas such as coal-fired power units, industrial kilns, and coal-fired heating boilers. Background Technology

[0002] The limestone-gypsum wet desulfurization process is currently the most mature, stable, and adaptable mainstream desulfurization technology in the field of industrial flue gas desulfurization. With its outstanding advantages such as large desulfurization capacity, good adaptability to ultra-low emissions, and resource recovery of by-products, it is widely used in various large-scale industrial flue gas treatment projects. The core reaction mechanism of this process is as follows: Alkaline limestone slurry reacts with sulfur dioxide in the flue gas via a gas-liquid phase mass transfer neutralization reaction to generate calcium sulfite as an intermediate product. Then, through forced aeration oxidation, the unstable calcium sulfite is converted into stable calcium sulfate. After crystallization, dehydration, and refining, industrial gypsum is produced, simultaneously achieving flue gas desulfurization and purification as well as solid waste resource utilization.

[0003] During long-term continuous industrial operation, traditional wet desulfurization devices still have several inherent technical shortcomings, making it difficult to meet the current industry requirements of high standards for ultra-low emissions and energy conservation: First, traditional desulfurization towers mostly adopt a single-layer homogeneous spray structure, with limited gas-liquid mass transfer contact area and poor spray uniformity. Under low unit load and low sulfur flue gas conditions, the desulfurization efficiency fluctuates greatly, making it difficult to continuously and stably meet ultra-low emission standards. Second, traditional devices use a single-particle-size limestone slurry feeding mode. Large-particle limestone powder has a small specific surface area, poor reaction activation, and incomplete reaction, resulting in low material utilization. Fine powder particles are easily carried away by the flue gas, causing material waste and secondary pollution from flue gas entrainment. Third, traditional oxidation aeration systems adopt a uniform aeration mode throughout the entire area, with varying slurry reaction rates and solubility in different areas of the tower. Significant differences in oxygen demand can easily lead to localized oxygen deficiency, resulting in localized enrichment, crystallization, and scaling of calcium sulfite. This causes blockages in spray nozzles, delivery pipelines, and rectifier grids, leading to frequent equipment failures, long downtime for maintenance, and high operating costs. Fourth, traditional slurry filtration and purification structures are simple and can only intercept large particulate impurities, failing to effectively remove fine suspended clumps and agglomerated impurities. Long-term operation can easily lead to pipeline siltation and a reduction in spray atomization effect, further reducing the desulfurization stability of the system. Fifth, traditional equipment mostly operates at constant power and fixed frequency, unable to adaptively adjust operating parameters according to dynamic changes in flue gas load and inlet sulfur concentration. The overall energy consumption of the system is relatively high, and uneven oxidation leads to low purity and high impurity content in gypsum crystals, significantly reducing the resource utilization value of by-products.

[0004] Existing industry improvement solutions mostly focus on single-structure optimization, making only partial modifications to the spray structure or aeration method. They fail to systematically address comprehensive technical issues such as fluctuating desulfurization efficiency, scaling and clogging within the tower, high operating energy consumption, poor gypsum quality, and low material utilization. These optimizations are limited and difficult to adapt to the current industrial development needs for ultra-low emissions, energy conservation and carbon reduction, and efficient resource utilization of solid waste. Therefore, developing a staged limestone-gypsum wet desulfurization system with optimized structure, strong adaptability to operating conditions, high efficiency and energy saving, long-term anti-clogging and anti-scaling properties, and excellent by-product quality has significant engineering application value and market promotion significance. Summary of the Invention

[0005] (a) Purpose of the invention

[0006] The purpose of this invention is to overcome the technical defects of existing traditional wet desulfurization devices and provide a high-efficiency, low-resistance, and anti-clogging staged limestone-gypsum wet desulfurization method. This method solves technical problems such as uneven mass transfer during spraying, easy scaling inside the tower, easy siltation and blockage in pipelines, low utilization rate of limestone materials, high energy consumption during variable operating conditions, poor quality of by-product gypsum, and insufficient stability during low-load operation. It achieves a comprehensive improvement in desulfurization efficiency, material utilization rate, gypsum quality, and system operation stability, while reducing equipment maintenance costs and system operating energy consumption.

[0007] (II) Technical Solution

[0008] To achieve the above-mentioned objectives, the present invention adopts the following technical solution:

[0009] A high-efficiency, low-resistance, and anti-clogging staged limestone-gypsum wet desulfurization method includes a flue gas pretreatment module, a desulfurization absorption tower module, a slurry circulation activation module, a zoned oxidation aeration module, a gypsum dewatering and refining module, and an intelligent control module. The flue gas pretreatment module is used to complete flue gas dust removal, cooling, pressure stabilization and rectification, eliminating the interference of flue gas parameter fluctuations on the desulfurization reaction and constructing a stable desulfurization reaction condition; the desulfurization absorption tower module maximizes the gas-liquid mass transfer efficiency and eliminates the blind zone of the spray reaction through a double-layer staggered differentiated spray and flue gas rectification and flow equalization structure; the slurry circulation activation module improves the reaction utilization rate of limestone materials through gradient particle size slurry graded feeding, slurry activation homogenization, and multi-stage online self-cleaning filtration structure, eliminating the problem of equipment blockage and sludge accumulation from the source; the zoned oxidation aeration module adopts a zoned independent and controllable aeration mechanism to accurately match the slurry oxidation needs of different areas and inhibit the enrichment and scaling of calcium sulfite; the gypsum dehydration and refining module realizes efficient dehydration and refining of gypsum crystals and closed-loop reuse of process water resources; the intelligent control module realizes adaptive matching and control of the operating parameters of the entire system, realizing energy-saving operation on demand.

[0010] The core innovations of this invention are as follows: It employs a gradient particle size slurry and a double-layer differentiated spraying precision matching technology to achieve precise desulfurization under full load and full sulfur concentration conditions; it utilizes zoned independent aeration and dissolved oxygen precision control technology to overcome industry challenges such as localized oxidation imbalance and scaling within the tower; it integrates a multi-stage filtration self-cleaning and slurry activation homogenization system to achieve long-term, clog-free, and stable operation of the equipment; and it relies on intelligent frequency conversion adaptive control technology to achieve energy-saving and carbon-reducing operation of the system, simultaneously improving desulfurization and purification efficiency and the quality of by-product gypsum.

[0011] (III) Beneficial Effects

[0012] Compared with existing technologies, this invention has the following outstanding advantages:

[0013] 1. High desulfurization efficiency and wide adaptability: The double-layer staggered atomizing spray combined with the arc-shaped rectification and flow equalization structure completely eliminates spray dead corners and mass transfer blind spots. The gradient slurry graded feeding mode can adapt to the complex fluctuation conditions of high and low load and high and low sulfur concentration of the unit. The system desulfurization efficiency is stable at ≥99%, which can meet the ultra-low emission control indicators of industrial flue gas for a long time.

[0014] 2. Long-lasting anti-clogging and anti-scaling, low operation and maintenance costs: The zoned precise aeration mechanism completely eliminates the local enrichment and scale deposition of calcium sulfite. Combined with multi-level gradient self-cleaning filtration, in-situ nozzle self-cleaning, and slurry activation and homogenization multi-protection structure, it solves the problem of blockage and sludge accumulation in pipelines, nozzles, and tower body from the root, greatly reducing the equipment failure rate by more than 80%, effectively reducing the frequency of downtime maintenance and operation and maintenance investment.

[0015] 3. Significant energy saving and consumption reduction, and high material utilization rate: The entire system adopts an intelligent frequency conversion on-demand control mode. The aeration, slurry supply, and air supply equipment can all adaptively adjust their operating power according to real-time operating conditions. Combined with the closed-loop recycling system for process water resources, the overall energy consumption of the system is reduced by more than 12%. The gradient particle size slurry accurately matches the reaction requirements, and the effective reaction utilization rate of limestone materials is increased by 15%~20%, which greatly reduces material waste and reagent consumption.

[0016] 4. Excellent quality and high resource value of by-products: Precise and controllable zoned oxidation and constant temperature crystallization conditions ensure uniform growth of calcium sulfate crystals and extremely low impurity content. The finished gypsum has a purity of ≥95% and a moisture content of ≤8%, which can be directly applied to building material processing, gypsum product production and other fields, realizing efficient resource utilization of solid waste and improving the economic benefits of the project.

[0017] 5. High degree of automation and good operational stability: Real-time monitoring and intelligent adaptive control of operating parameters throughout the entire process, eliminating the need for frequent manual intervention and adjustment. It can be adapted to the 24-hour continuous and stable operation of industrial units, making it suitable for a wide range of scenarios and extremely valuable for engineering promotion and implementation. Attached Figure Description

[0018] Figure 1 This is a flowchart of a high-efficiency, low-resistance, and anti-clogging staged limestone-gypsum wet desulfurization method according to the present invention. Detailed Implementation

[0019] The present invention will be further described in detail and in complete form below with reference to specific embodiments, but the implementation of the present invention is not limited thereto.

[0020] This invention discloses a high-efficiency, low-resistance, and anti-clogging staged limestone-gypsum wet desulfurization method, which is composed of a flue gas pretreatment module, a desulfurization absorption tower module, a slurry circulation activation module, a zoned oxidation aeration module, a gypsum dewatering and refining module, and an intelligent control module. The modules work together in a closed loop to complete the entire process of industrial flue gas desulfurization and purification, slurry circulation activation, slurry oxidation crystallization, and gypsum dewatering and refining.

[0021] The flue gas pretreatment module is sequentially equipped with dust removal equipment, a flue gas cooling heat exchanger, and a booster fan along the flue gas flow direction. The raw industrial flue gas first enters the dust removal equipment, which efficiently removes solid impurities such as dust and particulate matter, preventing these impurities from entering the desulfurization tower, contaminating the reaction slurry, abrading the equipment's inner walls, and clogging the delivery pipelines. The high-temperature flue gas after dust removal enters the flue gas cooling heat exchanger, which cools the raw high-temperature flue gas (140-150℃) to the optimal reaction temperature of the limestone slurry (90-100℃), while simultaneously recovering waste heat from the flue gas, reducing the overall energy consumption of the system. The cooled flue gas is then stabilized and its speed adjusted by the booster fan, eliminating unstable factors such as turbulence and flow fluctuations, ensuring that the flue gas is delivered to the desulfurization absorption tower at a constant flow rate and in a uniform state, stabilizing the desulfurization reaction conditions.

[0022] The desulfurization absorption tower module adopts a vertical closed tower structure. From top to bottom, the tower is equipped with two-stage baffle demisters, double-layer staggered atomizing spray components, arc-shaped flue gas equalization and rectification grid, and slurry oxidation storage tank. The two-stage baffle demister is equipped with high-pressure flushing nozzles in its interlayer area, which can efficiently capture the fine slurry droplets carried by the flue gas after desulfurization, keeping the water content of the flue gas below 0.5%, effectively avoiding subsequent problems such as flue corrosion, slurry loss, and white smoke from the chimney. The double-layer staggered atomizing spray assembly consists of upper and lower layers with nozzles evenly arranged in a staggered pattern, eliminating blind spots in the spraying area. The upper layer uses large-aperture, high-flow-rate nozzles to meet the high-load, high-sulfur flue gas desulfurization requirements of the unit, while the lower layer uses small-aperture, high-precision atomizing nozzles to enhance the fine desulfurization effect of low-load, low-sulfur flue gas. The arc-shaped flue gas flow equalization and rectification grid can disperse and rectify turbulent flue gas, making the flue gas evenly dispersed throughout the spraying cross section, effectively extending the gas-liquid two-phase mass transfer reaction time and significantly improving the sulfur dioxide adsorption and removal efficiency. The slurry oxidation storage tank at the bottom of the tower provides a stable reaction space for slurry neutralization reaction, forced oxidation, and crystal crystallization.

[0023] The slurry circulation activation module adopts an integrated, partitioned, dual-compartment gradient slurry storage tank, divided into a coarse-particle slurry storage compartment and a fine-particle slurry storage compartment. It stores limestone slurry of different particle sizes in separate compartments and precisely matches the upper and lower spray layers to achieve differentiated and precise feeding: 80~120μm coarse-particle slurry is matched with the upper high-flow-rate spray layer to meet the reaction requirements of large materials under high-load conditions; 30~60μm fine-particle slurry is matched with the lower fine-particle spray layer, leveraging its large specific surface area to improve the reaction removal efficiency of low-concentration sulfur dioxide. A high- and low-speed composite stirring mechanism operates continuously. Low-speed stirring is the norm, ensuring overall homogeneity of the slurry without stratification or segregation. High-speed stirring uses an intermittent start-stop mode, starting every 30 minutes and running for 5 minutes at a time to activate and disperse the static slurry, preventing sedimentation, agglomeration, and clumping. The multi-stage self-cleaning filter assembly consists of a pre-filter coarse screen and a post-filter precision core, progressively intercepting large particles and fine suspended agglomerates. A high-pressure backwashing pipeline periodically introduces high-pressure, stabilized process water to automatically backwash and descale the filter assembly without requiring equipment shutdown, thus addressing the root cause of slurry pipeline and spray nozzle blockage. The variable frequency conveying circulation pump adaptively adjusts the slurry supply flow rate based on flue gas flow and inlet sulfur dioxide concentration, achieving precise on-demand slurry supply and effectively reducing material conveying energy consumption.

[0024] The zoned oxidation aeration module adopts a zoned, independently controllable aeration architecture, dividing the slurry oxidation tank into a central high-aeration reaction zone and a peripheral steady-state oxygen supplementation zone. Each zone is independently equipped with oxidation blowers and distributed aeration pipelines, allowing for independent and precise control of airflow and pressure. Multiple dissolved oxygen sensors monitor the dissolved oxygen content of the slurry in both zones in real time. Under high-sulfur, high-load conditions, the aeration airflow in the central high-aeration zone is increased to enhance the oxidation conversion efficiency of calcium sulfite in the core reaction zone. Under low-sulfur, low-load conditions, the overall aeration load is reduced to maintain dissolved oxygen balance in the peripheral oxygen supplementation zone, ensuring complete oxidation of calcium sulfite into stable calcium sulfate crystals throughout the tower and completely eliminating scaling, deposition, and tower blockage problems caused by insufficient local oxidation. The system stably controls the dissolved oxygen concentration of the slurry at 2.5~3.5 mg / L and the oxidation crystallization temperature at 45~55℃, providing optimal reaction conditions for uniform and stable crystallization of calcium sulfate.

[0025] The gypsum dewatering and refining module uses a gypsum delivery pump to transport the high-concentration calcium sulfate crystal slurry enriched in the oxidation storage tank to a hydrocyclone separator. Centrifugal force is used to complete primary solid-liquid separation, with large gypsum crystals accumulating at the bottom of the hydrocyclone, while the finer slurry is returned to the tower for further recycling. The high-concentration gypsum slurry after primary separation is then fed into a vacuum belt dewatering device, where negative pressure adsorption dewatering achieves deep solid-liquid separation, ultimately producing a high-quality gypsum product with a moisture content ≤8% and a purity ≥95%, which can be directly utilized externally. The filtrate generated during dewatering is entirely transported back to the gradient-stage slurry storage tank via a filtrate recovery and reuse component and a reflux pump, achieving a closed-loop recycling of process water resources with no external discharge of production wastewater, thus saving energy and protecting the environment.

[0026] The intelligent control module integrates flue gas parameter monitoring, slurry status monitoring, equipment operation monitoring, and adaptive control units. It collects core operating condition data in real time, such as flue gas flow rate, inlet SO2 concentration, flue gas temperature, slurry pH value, dissolved oxygen concentration, and equipment operating power. Through built-in optimized control algorithms, it adaptively adjusts the operating parameters of the booster fan, circulating pump, oxidation fan, and mixing mechanism, realizing automated, intelligent, and energy-saving operation of the entire system. It eliminates the need for frequent manual intervention and adjustment, significantly reducing manual operation and maintenance costs.

[0027] The desulfurization process of this invention is continuous and compact, with strong adaptability to operating conditions. The specific operation process is as follows: First, the flue gas is pretreated by dust removal, cooling, and pressure stabilization to establish a stable desulfurization condition; after rectification and equalization, the pretreated flue gas is fully mass-transferred with the double-layer gradient spray slurry to complete the neutralization and removal of sulfur dioxide; through zoned precise aeration, calcium sulfite is uniformly oxidized and crystallized throughout the entire area; after filtration to remove impurities, activation and homogenization, the slurry is recycled to improve material utilization; after the slurry crystals are enriched to meet the standards, they are graded, dehydrated and refined to produce high-quality gypsum products; after the clean flue gas is purified by demisting, ultra-low emission standards are achieved. The entire process is closed-loop, energy-saving, efficient, and highly stable.

Claims

1. A high-efficiency, low-resistance, anti-clogging staged limestone-gypsum wet desulfurization method, characterized in that, It includes a flue gas pretreatment module, a desulfurization absorption tower module, a slurry circulation activation module, a zoned oxidation aeration module, a gypsum dewatering and refining module, and an intelligent control module; The flue gas pretreatment module is arranged in sequence along the flue gas conveying direction, including dust removal equipment, flue gas cooling heat exchanger, and booster fan, which are used to remove solid particulate impurities from the original flue gas, precisely control the flue gas temperature and conveying flow rate, stabilize the operating conditions of the desulfurization inlet flue gas, and the pretreated clean low-temperature flue gas is directionally conveyed to the inside of the desulfurization absorption tower module. The desulfurization absorption tower module is equipped with a vertical sealed tower body. Inside the tower body, from top to bottom, a demisting component, a double-layer staggered atomizing spray component, a flue gas equalization and rectification grid, and a slurry oxidation storage tank are fixedly assembled. The slurry circulation activation module includes a gradient grading slurry storage tank, a variable frequency conveying circulation pump, a multi-stage self-cleaning filter component, and a slurry homogenization activation stirring component. The gradient grading slurry storage tank is connected to the upper and lower spray layers of the double-layer staggered atomizing spray component through independent conveying pipelines to achieve precise zoning of limestone reaction slurry with different particle size gradients. The partitioned oxidation aeration module includes two sets of independent and controllable oxidation blowers, a distributed partitioned aeration pipeline group, and a multi-point dissolved oxygen detection component. The distributed partitioned aeration pipeline is arranged in layers and fixed inside the slurry oxidation storage tank to realize refined aeration oxidation operation with independent partitions and controllable air volume. The gypsum dewatering and refining module includes a gypsum conveying and discharge pump, a hydrocyclone separator, a vacuum belt dewatering device, and a filtrate recovery component, which are used to perform graded solid-liquid separation, deep dewatering and refining of gypsum crystals, and closed-loop recycling and reuse of filtrate in the desulfurization saturated slurry enriched in the tower. The intelligent control module is electrically connected to the flue gas pretreatment module, desulfurization absorption tower module, slurry circulation activation module, zoned oxidation aeration module, and gypsum dewatering and refining module, respectively. It is used to collect the operating parameters of the entire system in real time and adaptively match and control the operating parameters of each device according to the flue gas load, inlet sulfur concentration, and slurry operating status.

2. The high-efficiency, low-resistance, anti-clogging staged limestone-gypsum wet desulfurization system according to claim 1, characterized in that, The dual-layer staggered atomizing spray assembly includes an upper spray layer and a lower spray layer arranged correspondingly. The atomizing nozzles of the upper and lower spray layers are evenly arranged in a staggered manner, eliminating spray dead angles and reaction blind zones throughout the entire area. The atomizing nozzles adopt a conical hollow wide-angle atomizing structure, and each nozzle tip integrates an integrated micro self-cleaning nozzle. The upper spray layer is equipped with large-aperture, high-throughput atomizing nozzles, suitable for high-load, high-sulfur-concentration flue gas desulfurization conditions of the unit. The lower spray layer is equipped with small-aperture, high-precision atomizing nozzles, realizing the fine adsorption and removal of trace amounts of sulfur dioxide in low-load, low-sulfur-concentration flue gas.

3. The high-efficiency, low-resistance, anti-clogging staged limestone-gypsum wet desulfurization system according to claim 1, characterized in that, The gradient grading slurry storage tank is an integrated, partitioned double-compartment structure, divided into a coarse-particle slurry storage compartment and a fine-particle slurry storage compartment. The coarse-particle slurry storage compartment stores limestone slurry with a particle size of 80~120μm, and the corresponding pipeline is connected to the upper spray layer. The fine-particle slurry storage compartment stores limestone slurry with a particle size of 30~60μm, and the corresponding pipeline is connected to the lower spray layer. The slurry homogenization and activation stirring component is a high-low speed composite stirring mechanism. The low-speed stirring operates continuously to ensure that the slurry is homogeneous and does not stratify, while the high-speed stirring adopts an intermittent start-stop working mode to activate and disperse the static slurry, effectively avoiding slurry sedimentation, agglomeration, and clumping.

4. The high-efficiency, low-resistance, anti-clogging staged limestone-gypsum wet desulfurization system according to claim 1, characterized in that, The multi-stage self-cleaning filtration assembly includes a pre-filter, a post-filter, and a matching high-pressure backwashing pipeline. The pre-filter is used to trap large particles and agglomerates in the slurry, while the filter is used to intercept fine suspended impurities in the slurry. The high-pressure backwashing pipeline is connected to a pressure-stabilized process water system, which can automatically perform backwashing and descaling of the filtration assembly at regular intervals, enabling the equipment to self-clean online without stopping the machine and completely eliminating the problems of blockage and siltation in the slurry delivery pipeline.

5. The high-efficiency, low-resistance, anti-clogging staged limestone-gypsum wet desulfurization system according to claim 1, characterized in that, The distributed zoned aeration pipeline group is divided into a central strong aeration reaction zone and an edge steady-state oxygen supplementation zone. Each of the two functional aeration zones is independently matched with a set of controllable oxidation fans, and the air volume and air pressure of each zone can be adjusted independently. The multi-point dissolved oxygen detection component is deployed inside the slurry in the central strong aeration reaction zone and the edge steady-state oxygen supplementation zone to monitor the dissolved oxygen content of the slurry in different areas in real time, and adjust the aeration air volume and air pressure of each zone accordingly. By enhancing the oxidation efficiency of the main reaction in the central area and maintaining the overall oxidation balance in the edge area, the local enrichment, scaling and deposition of calcium sulfite are inhibited from the source.

6. The high-efficiency, low-resistance, anti-clogging staged limestone-gypsum wet desulfurization system according to claim 1, characterized in that, The flue gas flow equalization and rectification grid adopts an integral arc-shaped multi-hole rectification structure and is fixedly installed below the double-layer staggered atomizing spray assembly and above the slurry oxidation storage tank. It is used to rectify and disperse the turbulent flue gas entering the tower, so that the flue gas is evenly dispersed throughout the entire spray atomization reaction area, effectively extending the gas-liquid two-phase mass transfer reaction time.

7. The high-efficiency, low-resistance, anti-clogging staged limestone-gypsum wet desulfurization system according to claim 1, characterized in that, The demisting assembly includes two symmetrically arranged baffle-type demisters. High-pressure flushing nozzles are evenly distributed in the interlayer area of ​​the two-stage baffle-type demisters to efficiently capture the fine slurry droplets carried by the flue gas after desulfurization, effectively reducing the water carryover rate of the flue gas and avoiding subsequent problems such as flue corrosion, equipment scale buildup, and slurry material loss.

8. The high-efficiency, low-resistance, anti-clogging staged limestone-gypsum wet desulfurization system according to claim 1, characterized in that, The filtrate recovery and reuse component collects the filtrate generated during the deep dehydration of gypsum and uses a dedicated filtrate return pump to return the filtrate to the gradient grading slurry storage tank, realizing a closed-loop recycling of desulfurization slurry and process water resources, effectively reducing the system's process water consumption and the total amount of production wastewater discharged.

9. A high-efficiency, low-resistance, anti-clogging staged limestone-gypsum wet desulfurization process, characterized in that, The high-efficiency, low-resistance, anti-clogging staged limestone-gypsum wet desulfurization system according to any one of claims 1-8 includes the following continuous operation steps: S1. Flue gas pretreatment: The original high-temperature flue gas emitted by thermal power units or industrial kilns is first removed by dust removal equipment to remove solid particulate impurities, and then the high-temperature flue gas is regulated to the optimal reaction temperature of 90~100℃ by flue gas cooling heat exchanger. Finally, it is delivered to the desulfurization absorption tower at a constant flow rate by pressure-stabilized and speed-regulated booster fan. S2. Staged gas-liquid mass transfer desulfurization: The pretreated low-temperature stable flue gas passes through the flue gas uniform flow rectification grid from bottom to top and enters the spray reaction zone evenly. It fully contacts and transfers mass with the gradient particle size limestone slurry sprayed by the double-layer staggered atomizing spray component. The sulfur dioxide in the flue gas undergoes an acid-base neutralization reaction with the limestone slurry, completing the initial removal of sulfur dioxide. S3. Zoned Refined Oxidation Reaction: The slurry that has completed the initial desulfurization reaction falls back to the slurry oxidation storage tank at the bottom of the tower. The intelligent control module adaptively controls the operating parameters of the two sets of independent controllable oxidation blowers based on the real-time monitored dissolved oxygen concentration and slurry temperature parameters. This achieves high-intensity aeration in the central area and steady-state oxygen supplementation aeration in the edge area, promoting the full and uniform oxidation of the calcium sulfite generated in the reaction to form calcium sulfate crystals. S4. Slurry circulation activation and anti-clogging: After the oxidation reaction is completed, the slurry is filtered by a multi-stage self-cleaning filter to remove impurities and agglomerated lumps. Then, it is transported by a variable frequency conveying circulation pump to the double-layer staggered atomizing spray assembly to participate in the desulfurization reaction. At the same time, the high and low speed composite stirring mechanism is intermittently started to activate the slurry and prevent the slurry from settling and agglomerating and the pipeline from accumulating and clogging. S5. Gypsum grading, dewatering and refining: When the concentration of calcium sulfate crystals inside the slurry oxidation storage tank reaches the enrichment threshold set by the system, the gypsum conveying and discharge pump is started to transport the high-concentration crystal slurry to the hydrocyclone separator to complete the primary solid-liquid separation. The high-concentration gypsum slurry after hydrocyclone separation is sent to the vacuum belt dewatering equipment to complete the deep dewatering and obtain high-purity finished gypsum. All the filtrate produced by dewatering is recycled and reused. S6. Ultra-low emission of flue gas demisting: After the clean flue gas has been desulfurized and purified, it is completely removed from the fine slurry droplets by a two-stage baffle demister and then passes through the chimney to achieve ultra-low emission standards.

10. The high-efficiency, low-resistance, anti-clogging staged limestone-gypsum wet desulfurization process according to claim 9, characterized in that: In step S2, the pH value of the slurry in the tower is stably controlled at 5.2~5.8, and the liquid-to-gas ratio of the system is precisely adjusted to 18~22L / Nm³; in step S3, the dissolved oxygen concentration inside the slurry oxidation storage tank is maintained at 2.5~3.5mg / L, and the slurry oxidation crystallization temperature is controlled at 45~55℃.

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