Desulfurization wastewater clarification system

Abstract

The invention relates to the field of power plant desulfurization wastewater treatment, in particular to a desulfurization wastewater clarification system. The system comprises a pretreatment unit and a clarification unit, the pretreatment unit comprises an absorption tower, a gypsum cyclone, a dehydration suite and a gypsum overflow box, the absorption tower is communicated with the gypsum cyclone, and the gypsum cyclone can be communicated with the gypsum overflow box and the dehydration suite; the dehydration suite is communicated with the clarification unit, the clarification unit comprises a multi-stage sedimentation clarification tank, and the multi-stage sedimentation clarification tank is respectively communicated with the absorption tower, the dehydration suite and / or the gypsum overflow box. According to the desulfurization wastewater clarification system provided by the embodiment of the invention, the pretreatment unit and the clarification unit are integrated, and the synergistic effect of the absorption tower, the gypsum cyclone, the dehydration suite and the gypsum overflow box is utilized, so that effective pre-separation and multi-stage sedimentation clarification of desulfurization wastewater are realized.

Description

Technical Field

[0001] The present invention relates to the field of desulfurization wastewater treatment in power plants, and particularly to a desulfurization wastewater clarification system. Background Art

[0002] In coal-fired power plants, the wet desulfurization process is widely used to remove sulfur dioxide (SO2) from flue gas. However, this process generates desulfurization wastewater with complex components, including heavy metals, chloride ions, sulfates, and other suspended solids. Direct discharge of these untreated or inadequately treated wastewater will cause serious environmental pollution.

[0003] Currently, in the field of desulfurization wastewater treatment, the commonly adopted method is clarification after adding chemical agents. This method is mainly achieved through the "three-chamber" system, that is, the raw wastewater sequentially passes through the neutralization chamber, sedimentation chamber, and flocculation chamber, and calcium hydroxide, organic sulfur, flocculants (such as polyferric chloride), and coagulants (such as PAM) are added at each stage respectively. Through repeated stirring and mixing, the raw wastewater enters the clarifier for neutralization, flocculation, and precipitation. Finally, the supernatant is discharged as treated wastewater, while the bottom sediment is regarded as sludge for dewatering treatment. In this process, the raw wastewater first starts from the neutralization chamber, then enters the sedimentation chamber and flocculation chamber, and finally enters the clarifier. The supernatant of the clarifier can be further treated or directly discharged, while the bottom sediment needs to be dehydrated through equipment such as plate and frame filter presses and finally transported out for disposal.

[0004] Although the above method can remove pollutants in desulfurization wastewater to a certain extent, it has the following several significant problems:

[0005] Risk of secondary pollution: Due to the need to add a large amount of chemical agents, it may lead to excessive residual dosage of chemicals in the treated water, increasing the difficulty of subsequent treatment and potentially causing secondary pollution problems such as pH imbalance and salt accumulation.

[0006] High cost: The cost of chemical agents is relatively high. Coupled with the electricity consumption, equipment maintenance, and sludge disposal costs, the overall operating cost is high.

[0007] Complexity of the process: The entire treatment process covers multiple links, and precise parameter control is required for each step. The operation is difficult, and the requirements for equipment are high, increasing the failure rate and maintenance cost.

[0008] Resource waste: The traditional treatment method fails to effectively recycle useful components in the sludge, such as gypsum, resulting in resource waste. In addition, due to the large amount of sludge generated, the treatment and transportation costs are also correspondingly increased.

[0009] Therefore, there is an urgent need for a more environmentally friendly, economical, and efficient desulfurization wastewater treatment technology to solve the above problems. Summary of the Invention

[0010] (1) Technical problems to be solved

[0011] In view of the above-mentioned disadvantages and deficiencies of the prior art, the present invention provides a desulfurized wastewater clarification system. By introducing a pre-separation and a three-stage physical clarification process, the system solves the technical problems of high chemical agent dependence, high operating cost, generation of a large amount of difficult-to-treat sludge, and complex process and difficult management in the traditional desulfurized wastewater treatment process.

[0012] (2) Technical solutions

[0013] To achieve the above object, the main technical solutions adopted by the present invention include:

[0014] A desulfurized wastewater clarification system, which includes a pretreatment unit and a clarification unit. The pretreatment unit includes an absorption tower, a gypsum hydrocyclone, a dehydration kit, and a gypsum overflow tank. The absorption tower is connected to the gypsum hydrocyclone, and the gypsum hydrocyclone can be connected to the gypsum overflow tank and the dehydration kit; the dehydration kit is connected to the clarification unit, and the clarification unit includes a multi-stage sedimentation clarification tank, and the multi-stage sedimentation clarification tank is respectively connected to the absorption tower, the dehydration kit, and / or the gypsum overflow tank.

[0015] In some embodiments, the basic unit includes a boiler, an electrostatic precipitator, and an induced draft fan. One end of the boiler is connected to the electrostatic precipitator, and the other end of the electrostatic precipitator is connected to the absorption tower through the induced draft fan, and the absorption tower is connected to a chimney.

[0016] In some embodiments, the lower end of the absorption tower is connected to the gypsum hydrocyclone, the upper end of the gypsum hydrocyclone is connected to the upper end of the gypsum overflow tank, the lower end of the gypsum overflow tank is connected to the upper end of the absorption tower, and the lower end of the gypsum hydrocyclone is connected to the dehydration kit.

[0017] In some embodiments, the dehydration kit includes a gypsum dehydration vacuum belt kit, a gas-water separator, a dehydration vacuum pump, and a wastewater tank. The lower end of the gypsum hydrocyclone is connected to the gypsum dehydration vacuum belt kit, the gypsum dehydration vacuum belt kit is connected to the gas-water separator, one end of the gas-water separator is connected to the dehydration vacuum pump, and the other end of the gas-water separator is connected to the wastewater tank.

[0018] In some embodiments, the gypsum dehydration vacuum belt kit includes a first gypsum dehydration vacuum belt and a second gypsum dehydration vacuum belt. The first gypsum dehydration vacuum belt and the second gypsum dehydration vacuum belt are arranged in parallel, and the first gypsum dehydration vacuum belt and the second gypsum dehydration vacuum belt are respectively connected to the gas-water separator.

[0019] In some embodiments, the wastewater tank is connected to the clarification unit, and the clarification unit includes a first-stage clarification tank, a second-stage clarification tank, a third-stage clarification tank, and a storage tank that are connected in sequence from high to low, and the wastewater tank is connected to the first-stage clarification tank.

[0020] In some embodiments, the clarification unit further includes a sludge discharge pump. One end of the primary clarification tank is connected to one end of the sludge discharge pump, and the other end of the sludge discharge pump is respectively connected to the first gypsum dewatering vacuum belt and the second gypsum dewatering vacuum belt.

[0021] In some embodiments, the clarification unit further includes a sump. The primary clarification tank can also be connected to the absorption tower, and / or the primary clarification tank is connected to the gypsum overflow tank through the sump.

[0022] In some embodiments, the system further includes a gypsum concentration detector and a three-phase switch. A gypsum concentration detector is arranged between the primary clarification tank and the sludge discharge pump. The gypsum concentration detector is located above the three-phase switch between the primary clarification tank and the sludge discharge pump and close to the primary clarification tank.

[0023] In some embodiments, the secondary clarification tank is connected to the absorption tower, or the secondary clarification tank is connected to the gypsum overflow tank through the sump. There is a pump body in the sump to transport the gypsum to the gypsum overflow tank.

[0024] (III) Beneficial effects

[0025] The desulfurized wastewater clarification system provided by the embodiments of the present invention integrates the pretreatment unit and the clarification unit, and utilizes the synergistic effect of the absorption tower, the gypsum cyclone, the dehydration kit and the gypsum overflow tank to realize the effective pre-separation and multi-stage sedimentation clarification of the desulfurized wastewater. In the pretreatment unit, the connected design of the absorption tower and the gypsum cyclone enables the effective separation of high-chlorine wastewater, reducing the subsequent treatment difficulty; the application of the dehydration kit further reduces the solid content rate in the wastewater, laying a good foundation for the subsequent clarification process. The clarification unit adopts the design of multi-stage sedimentation clarifiers, which not only improves the removal efficiency of suspended solids, but also can flexibly adjust the functions of each stage of clarifiers according to needs to maximize the recovery of resources. Overall, the system significantly reduces the use of chemicals, reduces the operating cost, and significantly reduces the sludge volume through the recycling of resources such as gypsum, simplifies the process flow, improves the reliability and management efficiency of the system, and achieves the treatment goals of high efficiency, environmental protection and economy. Description of the drawings

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0027] Figure 1 is the desulfurization treatment system of the present invention;

[0028] Figure 2 is the desulfurized wastewater clarification system of the prior art;

[0029]

Description of the Attached Drawing Reference Signs

[0030] 1, basic unit; 2, pretreatment unit; 3, clarification unit; 4, absorption tower; 5, gypsum cyclone; 6, dehydration kit; 7, gypsum overflow tank; 8, boiler; 9, electrostatic precipitator; 10, induced draft fan; 11, chimney; 12, gypsum silo; 13, triple box; 14, clarification tank; 15, wastewater cyclone; 16, plate and frame filter press

[0031] 31, primary clarification tank; 32, secondary clarification tank; 33, tertiary clarification tank; 34, storage tank

[0032] 35, sludge discharge pump; 36, sump pit; 37, gypsum concentration detector; 38, three-phase switch

[0033] 61, gypsum dehydration vacuum belt kit; 62, gas-water separator; 63, dehydration vacuum pump; 64, wastewater tank

[0034] 611, first gypsum dehydration vacuum belt; 612, second gypsum dehydration vacuum belt Specific Embodiments

[0035] The following further describes in detail the embodiments of the present application in conjunction with the attached drawings and examples. The detailed descriptions and drawings of the following examples are used to exemplarily illustrate the principle of the present application, but cannot be used to limit the scope of the present application. The present application can be implemented in many different forms, not limited to the specific embodiments disclosed in the text, but including all technical solutions falling within the scope of the claims

[0036] These embodiments are provided to make the present application thorough and complete, and to fully convey the scope of the present application to those skilled in the art. It should be noted that: unless otherwise specifically stated, the relative arrangements of components and steps, the components of materials, numerical expressions and values described in these embodiments should be interpreted as merely exemplary, rather than as limitations

[0037] It should be noted that in the description of the present application, unless otherwise specified, "a plurality of" means greater than or equal to two; the orientation or positional relationships indicated by the terms "upper", "lower", "left", "right", "inner", "outer", etc. are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present application. When the absolute position of the described object changes, the relative position relationship may also change accordingly

[0038] In addition, the "first", "second" and similar terms used in this application do not denote any order, quantity or importance, but are only used to distinguish different parts. "Vertical" does not mean strictly vertical, but within the allowable error range. "Parallel" does not mean strictly parallel, but within the allowable error range. Similar terms such as "include" or "comprise" mean that the elements before this word cover the elements listed after this word, and do not exclude the possibility of also covering other elements.

[0039] It should also be noted that in the description of this application, unless otherwise clearly specified and limited, the terms "install", "connect", and "couple" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances. When it is described that a specific device is located between a first device and a second device, there may or may not be an intermediate device between the specific device and the first device or the second device.

[0040] All terms used in this application have the same meanings as understood by those of ordinary skill in the art to which this application belongs, unless otherwise specifically defined. It should also be understood that terms defined in a general dictionary, such as, should be interpreted as having meanings consistent with their meanings in the context of the relevant art, and should not be interpreted in an idealized or overly formal sense, unless specifically defined as such here.

[0041] Technologies, methods and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods and devices should be regarded as part of the specification.

[0042] See Figure 1 , a desulfurized wastewater clarification system, the system includes a pretreatment unit 2 and a clarification unit 3. The pretreatment unit 2 includes an absorption tower 4, a gypsum hydrocyclone 5, a dehydration kit 6 and a gypsum overflow tank 7. The absorption tower 4 is communicated with the gypsum hydrocyclone 5, and the gypsum hydrocyclone 5 can be communicated with the gypsum overflow tank 7 and the dehydration kit 6; the dehydration kit 6 is communicated with the clarification unit 3, and the clarification unit 3 includes a multi-stage sedimentation clarifier, and the multi-stage sedimentation clarifier is respectively communicated with the absorption tower 4, the dehydration kit 6 and / or the gypsum overflow tank 7.

[0043] Through the connection design between the absorption tower 4 and the gypsum hydrocyclone 5, highly chlorinated wastewater can be efficiently separated from the desulfurization slurry. This step significantly reduces the solid content of the wastewater entering the subsequent treatment stage, reduces the difficulty of subsequent clarification and treatment, and improves the overall treatment efficiency.

[0044] The gypsum hydrocyclone 5 can effectively separate the slurry containing a high concentration of gypsum and direct it to the dehydration kit 6 for further treatment. This process not only helps reduce the amount of sludge finally generated but also provides convenient conditions for the recycling of gypsum.

[0045] The clarification unit 3 adopts the design of a multi-stage sedimentation clarifier. By means of hierarchical treatment, the suspended solid content in the wastewater is gradually reduced to ensure that the final effluent meets higher water quality standards. Each stage of the clarifier can flexibly adjust its functions according to needs to adapt to different treatment requirements.

[0046] The connected design between the dehydration kit 6 and the clarification unit 3 enables the preliminarily treated wastewater to further remove the solid components therein and recover valuable by-products such as gypsum. This not only reduces the generation of waste but also realizes the maximization of resource utilization.

[0047] The design of the entire system simplifies the traditional complex desulfurized wastewater treatment process, reduces the demand for a variety of chemical reagents, thereby reducing the operation complexity and maintenance costs. In addition, the improvement of the automation level also reduces the need for manual intervention and lowers the labor cost.

[0048] Due to the adoption of a modular design, the connection between components is tight and the functions are clear, which enhances the stability and reliability of the system. For example, equipment such as the gypsum hydrocyclone 5, the dehydration kit 6, and the multi-stage sedimentation clarifier work together to ensure the continuity and stability of the entire treatment process.

[0049] In summary, the desulfurized wastewater clarification system realizes the goals of efficient, environmental protection, and economic wastewater treatment by integrating the pretreatment unit 2 and the clarification unit 3 and utilizing the synergistic effect of the absorption tower 4, the gypsum hydrocyclone 5, the dehydration kit 6, and the gypsum overflow tank 7, providing an enterprise with a sustainable development solution.

[0050] See Figure 1 , the basic unit 1 includes a boiler 8, an electrostatic precipitator 9, and a induced draft fan 10. One end of the boiler 8 is connected to the electrostatic precipitator 9, and the other end of the electrostatic precipitator 9 is connected to the absorption tower 4 through the induced draft fan 10, and the absorption tower 4 is connected to the chimney 11.

[0051] The electrostatic precipitator 9 can efficiently capture the fine particles (such as dust and fly ash) in the flue gas discharged from the boiler 8, and its efficiency can usually reach more than 99%. This not only reduces the particulate load entering the subsequent wet desulfurization system but also significantly reduces the risk of wear and blockage of the desulfurization equipment.

[0052] After most of the particulate matter is removed in advance by the electrostatic precipitator 9, the flue gas entering the absorption tower 4 is cleaner, which helps to improve the overall efficiency of the wet flue gas desulfurization process. The less interference from particulate matter enables the desulfurization agent to react more effectively with sulfur dioxide, thus improving the desulfurization efficiency.

[0053] The reasonable configuration of the induced draft fan 10 ensures the smooth transmission of the flue gas between various treatment links. At the same time, by optimizing the air volume and pressure settings, unnecessary energy consumption can be reduced, the effective utilization of energy can be achieved, and the operating cost can be further reduced.

[0054] See Figure 1 , the lower end of the absorption tower 4 is connected to the gypsum hydrocyclone 5, the upper end of the gypsum hydrocyclone 5 is connected to the upper end of the gypsum overflow tank 7, the lower end of the gypsum overflow tank 7 is connected to the upper end of the absorption tower 4, and the lower end of the gypsum hydrocyclone 5 is connected to the dehydration kit 6.

[0055] The gypsum hydrocyclone 5 can efficiently separate the solid and liquid of the gypsum slurry enriched at the bottom of the absorption tower 4, and effectively remove the solid particulate matter in the wastewater. This not only reduces the content of suspended solids entering the subsequent treatment steps, but also facilitates the further treatment and recycling of gypsum.

[0056] The gypsum-rich slurry separated by the gypsum hydrocyclone 5 can be directly sent to the dehydration kit 6 for further treatment, thus realizing the effective recovery of gypsum. The recovered gypsum can be used for building materials or other industrial purposes, achieving the maximum utilization of resources and reducing the generation of waste.

[0057] The design of connecting the upper end of the gypsum hydrocyclone 5 to the gypsum overflow tank 7 enables the relatively clean liquid after preliminary separation to return to the absorption tower 4 to continue participating in the desulfurization reaction, reducing the overall load of the system and improving the resource utilization rate. At the same time, this recycling mechanism also helps to maintain the stability of the chemical reaction environment in the absorption tower 4.

[0058] The close cooperation between the components of the system ensures the smooth and efficient operation of the entire process from the absorption tower 4 to the bottom gypsum treatment. This design reduces the operation interruption caused by equipment failure or performance decline, and enhances the stability and reliability of the system.

[0059] See Figure 1 , the dehydration kit 6 includes a gypsum dehydration vacuum belt kit 61, a gas-liquid separator 62, a dehydration vacuum pump 63 and a wastewater tank 64. The lower end of the gypsum hydrocyclone 5 is connected to the gypsum dehydration vacuum belt kit 61, the gypsum dehydration vacuum belt kit 61 is connected to the gas-liquid separator 62, one end of the gas-liquid separator 62 is connected to the dehydration vacuum pump 63, and the other end of the gas-liquid separator 62 is connected to the wastewater tank 64.

[0060] The gypsum dehydration vacuum belt kit 61 can efficiently remove the moisture in the gypsum slurry, generating gypsum cakes with a relatively low water content (usually with a moisture content of less than 12%). This not only facilitates subsequent transportation and storage but also enhances the commercial value of the gypsum as a by-product.

[0061] After being processed by the gypsum dehydration vacuum belt kit 61, the separated moisture enters the wastewater tank 64. This part of the wastewater can be recycled or discharged up to standard through further treatment, reducing the environmental impact. In addition, the design of the wastewater tank 64 also helps to centrally manage the wastewater, facilitating subsequent treatment steps.

[0062] The combined use of the air-water separator 62 and the dehydration vacuum pump 63 ensures the efficient progress of the dehydration process. The air-water separator 62 can effectively separate air and liquid, preventing the vacuum pump from inhaling moisture, thus protecting the equipment from damage, extending its service life, and improving the stability of the system operation.

[0063] See Figure 1 , the gypsum dehydration vacuum belt kit 61 includes a first gypsum dehydration vacuum belt 611 and a second gypsum dehydration vacuum belt 612. The first gypsum dehydration vacuum belt 611 and the second gypsum dehydration vacuum belt 612 are arranged in parallel, and the first gypsum dehydration vacuum belt 611 and the second gypsum dehydration vacuum belt 612 are respectively connected to the air-water separator 62.

[0064] Through the first gypsum dehydration vacuum belt 611 and the second gypsum dehydration vacuum belt 612 arranged in parallel, the system can process more gypsum slurry simultaneously, thus significantly improving the overall processing capacity. This not only helps to cope with peak loads but also ensures the stable operation of the system under high-load conditions.

[0065] The two gypsum dehydration vacuum belts arranged in parallel provide a redundant design. Even if one of the belts fails or needs maintenance, the other belt can still continue to work, ensuring the continuity and stability of the system. This design reduces the downtime caused by single-point failures and improves the overall reliability of the system.

[0066] The two gypsum dehydration vacuum belts can process the gypsum slurry more efficiently, ensuring that the quality of the gypsum cakes is more uniform and stable. High-quality gypsum cakes are convenient for subsequent transportation, storage, and reuse, further enhancing the efficiency and value of resource recovery.

[0067] The two gypsum dehydration vacuum belts arranged in parallel allow for the maintenance and repair of a single belt without shutting down the machine, greatly simplifying the maintenance process, reducing downtime, and minimizing the impact on production.

[0068] See Figure 1The wastewater tank 64 is connected to the clarification unit 3 , and the clarification unit 3 includes a primary clarification tank 31 , a secondary clarification tank 32 , a tertiary clarification tank 33 and a storage tank 34 which are connected in sequence from high to low. The wastewater tank 64 is connected to the primary clarification tank 31 .

[0069] Through the design of multi-stage sedimentation clarification tanks (primary clarification tank 31, secondary clarification tank 32, tertiary clarification tank 33), wastewater can be gradually separated from solid and liquid and clarified. Each tank is used to treat suspended solids of different particle sizes and densities, ensuring the gradual improvement of the treatment effect and ultimately achieving efficient wastewater clarification.

[0070] In each level of clarification tank, solid particles and suspended solids in wastewater can be removed by physical methods without adding chemical agents. This not only reduces the cost of agents, but also avoids the risk of secondary pollution. For example, larger particles of gypsum can be effectively separated in the primary clarification tank 31, which is convenient for subsequent recycling.

[0071] Since physical clarification methods are used instead of chemical reagent addition, the system significantly reduces reagent costs. In addition, the design of the multi-stage clarifier makes the workload of each pool relatively small, extending the service life of the equipment, reducing maintenance and replacement costs, and further reducing the overall operating cost.

[0072] The multi-stage clarification process can more thoroughly separate solid matter from wastewater, reducing the amount of sludge produced in the end. Compared with traditional methods, the total amount of sludge can be reduced by 95%, which not only reduces the cost of sludge disposal, but also reduces the burden on the environment.

[0073] The functions and operating parameters of each level of clarifier can be flexibly adjusted according to actual needs. For example, the primary clarifier 31 mainly settles large particles, the secondary clarifier 32 further removes fine particles, and the tertiary clarifier 33 can also perform final micro-suspended solids removal and water quality stabilization treatment. This flexibility makes the system easier to manage and operate, ensuring the best treatment effect.

[0074] After multi-stage clarification treatment, the quality of wastewater is more stable and reaches a higher purification standard. The clean water that finally enters the storage tank 34 can be reused for purposes such as spraying dust suppression in the coal yard or humidifying ash, achieving 100% reuse of wastewater, significantly reducing the demand for external water resources, and reducing the impact of emissions on the environment.

[0075] This compact and direct connection method simplifies the traditional complex desulfurization wastewater treatment process and reduces the intermediate links and equipment requirements. For example, the wastewater tank 64 is directly connected to the primary clarifier 31, avoiding additional transportation and storage steps, simplifying the operation process and reducing maintenance costs.

[0076] The tight cooperation among the components ensures a smooth and efficient whole treatment process from the wastewater tank 64 to the storage tank 34. This design reduces operation interruptions caused by equipment failures or performance degradation, enhancing the stability and reliability of the system.

[0077] See Figure 1 , the clarification unit 3 further includes a sludge discharge pump 35. One end of the first clarifier 31 is communicated with one end of the sludge discharge pump 35, and the other end of the sludge discharge pump 35 is respectively communicated with the first gypsum dewatering vacuum belt 611 and the second gypsum dewatering vacuum belt 612.

[0078] The sludge discharge pump 35 can effectively transport the sludge (mainly gypsum) enriched at the bottom of the first clarifier 31 to the gypsum dewatering vacuum belt kit 61 for further treatment. This design ensures that the sludge can be removed in a timely and efficient manner and enters the next treatment process.

[0079] By feeding the gypsum-rich sludge into the gypsum dewatering vacuum belt kit 61, the system can effectively recover and utilize gypsum. This not only reduces the generation amount of solid waste, but also realizes the maximization of resource utilization and improves the economic benefits.

[0080] The design of the sludge discharge pump 35 enables the sludge to be quickly discharged from the first clarifier 31, avoiding excessive accumulation of sludge in the tank, thereby reducing the workload and frequency of cleaning and maintenance.

[0081] The tight cooperation between the sludge discharge pump 35 and the gypsum dewatering vacuum belt kit 61 ensures the continuous operation of the whole system. Even under high load conditions, it can ensure the timely treatment of sludge and avoid system failures or efficiency degradation caused by sludge accumulation.

[0082] Timely discharging of sludge can prevent it from damaging the first clarifier 31 and other equipment, extending the service life of the equipment and improving the reliability and stability of the system.

[0083] By timely discharging the sludge in the first clarifier 31 through the sludge discharge pump 35, it ensures that the functions of each clarifier are fully exerted, enhancing the treatment efficiency of the whole system. The first clarifier 31 focuses on the sedimentation of large particles, while the second and third clarifiers 33 can focus more on the removal of fine particles and suspended matters, thus improving the water purification effect.

[0084] See Figure 1 , the clarification unit 3 further includes a sump 36. The first clarifier 31 can also be communicated with the absorption tower 4, and / or, the first clarifier 31 is communicated with the gypsum overflow tank 7 through the sump 36.

[0085] Connecting the primary clarifier 31 to the absorption tower 4 or the gypsum overflow tank 7 through the sump 36 enables flexible allocation and recycling of materials. For example, the supernatant containing a small amount of gypsum can flow back to the absorption tower 4 through the sump 36 to supplement the reactants in the absorption tower 4, increase the active components of the slurry, and enhance the desulfurization efficiency.

[0086] Returning a portion of the treated water in the primary clarifier 31 to the absorption tower 4 or the gypsum overflow tank 7 helps reduce water waste, maximally utilize the existing resources within the system, and lower the overall operating costs.

[0087] Through the design of the sump 36, it is possible to achieve balance in flow rate and load between different treatment units. For example, under high-load conditions, a portion of the wastewater can be transferred from the primary clarifier 31 to the gypsum overflow tank 7 or other treatment units through the sump 36 to avoid overloading of a single unit and ensure the stable operation of the entire system.

[0088] Connecting the primary clarifier 31 to other treatment units through the sump 36 allows adjustment of the material flow direction according to actual needs, enabling the full play of the functions of each treatment unit. For example, the primary clarifier 31 focuses on the sedimentation of large particles, and the treated water is sent to other units through the sump 36 for further clarification or reuse, enhancing the overall treatment efficiency.

[0089] Returning the treated water to the absorption tower 4 or the gypsum overflow tank 7 through the sump 36 reduces the emissions to the external environment, decreases the impact on the environment, and meets strict environmental protection standards.

[0090] See Figure 1 , the system further includes a gypsum concentration detector 37 and a three-phase switch 38. The gypsum concentration detector 37 is installed between the primary clarifier 31 and the sludge discharge pump 35, and the gypsum concentration detector 37 is located above the three-phase switch 38 between the primary clarifier 31 and the sludge discharge pump 35 and is close to the primary clarifier 31.

[0091] By setting a gypsum concentration threshold to determine the direction of the three-phase switch 38, it is thus determined whether the material returns to the absorption tower 4, the gypsum overflow tank 7, or the gypsum dewatering vacuum belt kit 61.

[0092] The gypsum concentration detector 37 can real-time monitor the gypsum concentration of the sludge in the primary clarifier 31 and automatically adjust the direction of the three-phase switch 38 according to the preset threshold. This enables the system to flexibly select the optimal material flow direction according to the actual working conditions, ensuring that each treatment unit can operate under optimal conditions.

[0093] When the gypsum concentration is low, the sludge can be recycled to the absorption tower 4 or the gypsum overflow tank 7. However, when the gypsum concentration is high, it is directly sent to the gypsum dewatering vacuum belt kit 61 for further treatment and recovery. This intelligent distribution method maximizes the utilization of resources within the system. By selecting different treatment paths according to different gypsum concentrations, the functions of each treatment unit are fully exerted. For example, high-concentration gypsum can directly enter the dehydration stage, while low-concentration gypsum can be recycled first to increase its concentration and then undergo subsequent treatment.

[0094] Through real-time monitoring and intelligent distribution, the system can effectively prevent equipment blockage or other failure problems caused by too high gypsum concentration. At the same time, reasonable material distribution also extends the service life of key equipment, improving the reliability and stability of the system. If a certain treatment unit fails or needs maintenance, the direction of the three-phase switch 38 can be adjusted to temporarily transfer the material to other units for treatment, reducing the downtime and enhancing the emergency response ability of the system.

[0095] The design of the gypsum concentration detector 37 and the three-phase switch 38 facilitates the realization of automatic control, reducing the need for manual intervention and enhancing the overall automation level and management level of the system.

[0096] Since the system can automatically adjust the material flow direction according to the gypsum concentration, the operator can more conveniently monitor and manage the entire system, ensuring that each treatment step is in the best state, thus improving the management efficiency of the system.

[0097] See Figure 1 , the secondary clarifier 32 is connected to the absorption tower 4, or the secondary clarifier 32 is connected to the gypsum overflow tank 7 through the sump 36. There is a pump body in the sump 36 to transport the gypsum to the gypsum overflow tank 7.

[0098] By recycling the treated water in the secondary clarifier 32 to the absorption tower 4 or the gypsum overflow tank 7, flexible allocation and recycling of materials can be achieved. For example, the supernatant containing a small amount of gypsum can be recycled to the absorption tower 4 through the sump 36, supplementing the reaction substances in the absorption tower 4, increasing the active components of the slurry, and enhancing the desulfurization efficiency.

[0099] Recycling a part of the treated water in the secondary clarifier 32 to the absorption tower 4 or the gypsum overflow tank 7 helps to reduce water resource waste, maximize the utilization of existing resources within the system, and reduce the overall operating cost.

[0100] The tertiary clarifier 33 mainly serves for storage.

[0101] Through tertiary physical clarification to replace chemical precipitation, sludge resources are recycled in stages, eliminating the use of chemicals.

[0102] Primary clarification (solid-liquid separation): The high-chloride wastewater enters the primary clarification tank 31, and while naturally settling, the gypsum-rich sludge at the bottom is discharged to the dewatering belt conveyor and mixed with the dehydrated gypsum for external transportation (water content <12%).

[0103] Secondary clarification (internal recycling): The supernatant of the primary clarifier 31 flows into the secondary clarifier 32 for secondary sedimentation, and the precipitated fine granular sludge containing part of gypsum is intermittently discharged into the ditch and returned to the desulfurization system.

[0104] Level 3 clarification (standing and reuse): The solid content of the secondary effluent is less than 1%, and it finally enters the 3,000 cubic meter desulfurization wastewater buffer pool for standing. The suspended solids in the wastewater are greatly reduced. When needed, the clear supernatant is directly reused for spraying dust suppression in the coal yard or humidifying ash, achieving 100% reuse of wastewater. The small amount of sludge that sinks to the bottom of the desulfurization wastewater buffer pool is cleaned regularly.

[0105] The desulfurization wastewater clarification system achieves full process optimization from pre-treatment to final resource recovery through a highly coordinated design. First, the absorption tower 4 works closely with the gypsum cyclone 5 to effectively separate high-chlorine wastewater and reduce the difficulty of subsequent treatment; the gypsum cyclone 5 further sends the gypsum-rich slurry into the dehydration kit 6 for efficient dehydration, and the resulting gypsum cake can be used for resource recovery. The primary clarifier 31, the secondary clarifier 32 and the tertiary clarifier 33 sequentially treat the wastewater in a graded manner, gradually remove suspended matter and optimize the water quality to ensure the final effluent quality. The setting of the pit 36 ​​and the pump body enables flexible allocation of materials between the treatment units to maximize the utilization of resources and maintain the load balance of the system. The introduction of the gypsum concentration detector 37 and the three-phase switch 38 dynamically adjusts the material flow direction according to the real-time monitoring data to ensure that each treatment step operates under optimal conditions. In addition, the entire system simplifies the operation process, reduces the need for manual intervention, and improves management efficiency and system stability through automated control and compact design. This highly coordinated design not only improves treatment efficiency and reduces operating costs, but also significantly reduces the impact on the environment.

[0106] This application is directly connected to the wastewater tank 64 through the gas-water separator 62, so that the solid content of the wastewater is reduced from 5% to 2%. The plate and frame filter press 16 and the wastewater cyclone 15 with a high failure rate are eliminated, and the failure rate is significantly reduced, because 90% of the failures in the enterprise occur in these two devices. The tertiary clarifier 33 is also called the desulfurization wastewater buffer tank. The sludge is reduced by 95%. The wastewater in the tank can be directly used for ash removal and humidification or coal yard dust suppression spraying, and there is very little sludge in it. Because there is very little sludge in the tertiary clarifier 33, it only needs to be cleaned once every 3 years.

[0107] Comparative Example 1

[0108] The raw desulfurized wastewater is added with substances such as calcium hydroxide, organic sulfur, flocculant (polyaluminum chloride), and coagulant aid (PAM) in the triple box 13 and stirred and mixed repeatedly. The mixed raw wastewater then enters the clarifier 14 for neutralization, flocculation, and sedimentation. The supernatant of the clarifier 14 is taken as the wastewater, and the sediment at the bottom of the clarifier 14 is taken as sludge for sludge dewatering treatment.

[0109] The system process is as follows:

[0110]

[0111] In the prior art, excessive use of chemicals causes secondary pollution. The composition of desulfurized wastewater is complex, and various chemical agents (such as calcium hydroxide, organic sulfur, flocculant polyaluminum chloride, coagulant aid PAM, and hydrochloric acid) need to be added for neutralization, precipitation, and heavy metal removal. However, excessive use of these chemicals will lead to residue problems, increase the difficulty of subsequent sludge treatment, and may cause risks of secondary pollution such as water body pH imbalance and salt accumulation. In addition, the chemical cost accounts for a large proportion of the total treatment cost, and excessive dosing significantly reduces the economic efficiency.

[0112] Huge sludge production. The raw desulfurized wastewater is separated from the slurry in the absorption tower 4. 95% of the sediment at the bottom of the clarifier 14 is gypsum in the slurry of the absorption tower 4. Since the gypsum in these sludges is treated as solid waste, a large amount of solid waste is generated, increasing the disposal cost and environmental burden.

[0113] High operating costs. The traditional "triple box 13" process relies on continuous dosing of chemicals and the operation of precision dosing equipment, involving chemical costs (10 yuan / ton of desulfurized wastewater), power consumption (2.5 yuan / ton of desulfurized wastewater), maintenance costs (11 yuan / ton of desulfurized wastewater), and sludge disposal costs (10 yuan / ton of desulfurized wastewater). The overall operating cost is extremely high, affecting the economic benefits.

[0114] Complex process flow and management problems. This process covers multiple links from wastewater pretreatment to final sludge dewatering, including multiple steps such as neutralization, flocculation, and clarification, and requires multiple-stage equipment to operate in series. The parameters of each link (such as pH value and chemical dosing amount) need to be accurately controlled, with a low operation error tolerance, and equipment failures are prone to occur. The long process not only occupies a large amount of space but also increases the difficulty of automatic control, raises the cost of manual inspection and maintenance, and limits the overall operating efficiency.

[0115] The labor intensity of workers is high. The plate and frame filter press 16 used in the sludge treatment process requires manual shoveling of mud, and at least two operators are involved in each shift, which is labor-intensive. The plate and frame machine frequently fails and requires maintenance every two days on average. In addition, the huge sludge output requires professional hauling vehicles to transport and process it regularly. Due to the high solid content of the slurry in the absorption tower 4, the wastewater cyclone 15 is seriously blocked, and it is frequently necessary to clean the blocked cyclone holes to maintain the normal operation of the wastewater discharge system.

[0116] See also Figure 2 , which is the desulfurization wastewater treatment system in our company's previous technology. The gas-water separator 62 is connected to the gypsum overflow box 7, the gypsum overflow box 7 is connected to the wastewater cyclone 15, and the wastewater cyclone 15 is connected to the wastewater tank 64. The wastewater tank 64 is first connected to the triple box 13. A variety of chemicals are added to the triple box 13 to treat sludge and wastewater. The treated wastewater enters the clarifier 14. A plate and frame filter press 16 is set inside the clarifier 14, and the clarifier 14 is connected to the wastewater tank.

[0117] The wastewater cyclone 15 uses centrifugal force to quickly separate the incoming slurry. The heavier solid particles (such as gypsum) are thrown toward the outer wall due to their greater inertia, and move downward along the wall surface and are finally discharged from the bottom; while the lighter liquid is concentrated in the central area and flows upward and is discharged through the top outlet. Due to the cyclone, the solid content in the wastewater tank 64 is at least 5%.

[0118] Through measures such as pre-separation + three-stage clarification and graded reuse, the high cost, high pollution and low efficiency problems of traditional processes have been systematically overcome, and the goal of "zero dosage, zero emission, and full resource reuse" for desulfurization wastewater treatment has been achieved, providing replicable technology and management examples for the green transformation of enterprises.

[0119] 1. Economic Results

[0120] Traditional sludge disposal is expensive and has environmental risks. The new technology classifies the gypsum in the sludge and reuses it in the production chain, achieving "waste treatment with waste" and resource value-added. After three-stage clarification, the suspended solids in the wastewater are about 60mg / L, no need to add drugs, and the cost of drugs is zero; the gypsum in the sludge is recycled or utilized, and the amount of sludge transported is reduced by 95%; the process flow is simplified, the equipment reliability is greatly improved, the workload is greatly reduced, and 9 workers are saved.

[0121] After adopting this technology, the operating cost per ton of desulfurization wastewater was reduced from 36.5 yuan to 2.85 yuan. The power plant produces 60,000 tons of desulfurization wastewater each year, saving a total of 2.019 million yuan in operating costs.

[0122] The following table compares the operating costs of this application and comparative example 1

[0123]

[0124] (2) Environmental protection achievements

[0125] First-stage sludge building material utilization: The sludge rich in gypsum in the first-stage clarifier 31 is mixed with dehydrated gypsum and then dewatered and transported out for the building materials industry, increasing the output of gypsum and saving the cost of separately transporting the gypsum in the sludge.

[0126] Second-stage sludge internal circulation: The sludge containing a small amount of gypsum is returned to the desulfurization system to supplement the reactive components in the absorption tower 4 and improve the slurry quality.

[0127] Third-stage harmless utilization of wastewater: The desulfurized wastewater settled in the final desulfurized wastewater buffer tank is used for spraying and dust suppression in the coal yard or humidifying ash and slag. The wastewater reuse rate is increased to 100%, significantly reducing the ecological risk.

[0128] (3) Management achievements

[0129] The new technology process is simple and reliable, without equipment prone to failure. Only three stable-operating sludge scrapers and two transfer pumps remain. The full-process automatic control and standardized management increase the operation error tolerance rate by 90%. The team's collaborative inspection and training assessment ensure the operation stability, and the fault response time is shortened to 30 minutes. The wastewater reuse rate reaches 100%, and the emissions of pollutants such as COD and SS decrease by 50%. The risk of chemical residue is eliminated, simultaneously achieving the goals of economy, environmental protection, and efficient management, providing a replicable example for the enterprise's green transformation.

[0130] In the first-stage clarifier 31 of this application, since the sedimentation rate of gypsum is faster than that of sludge, the first sedimented is gypsum. Therefore, the sedimented gypsum can be transported to the gypsum dehydration vacuum belt. Over time, some sludge mixes into the gypsum. When it exceeds the threshold, the relevant switch is closed, and the remaining part of the sludge water flows into the second-stage clarifier 32. The second-stage clarifier 32 mainly contains a mixture of sludge and gypsum. Therefore, it is transported to the absorption tower 4. The third-stage clarifier 33 contains the real sludge, with a small amount settling at the bottom of the sludge, which needs to be cleaned once every three years. By classifying and treating the sludge, this design reduces 95% of the sludge and eliminates the need to use the plate and frame filter press 16 to treat the sludge.

[0131] The plate and frame filter press 16 squeezes out the liquid in the sludge by applying pressure to achieve solid-liquid separation. It uses a group of alternately arranged filter plates and filter frames to form multiple filtration chambers, and the sludge to be treated is filled in these chambers. When hydraulic pressure is applied, the water penetrates through the filter cloth and is discharged, while the solid particles are retained on the filter cloth to form a sludge cake. In this application, due to the multi-stage sedimentation technology and the relatively small amount of sludge in the water coming from the wastewater tank 64 in the front, the finally sedimented sludge is too little, so there is no need to use the plate and frame filter press 16.

[0132] In addition, the present application proposes a method of alternately using two or more absorption towers 4 (such as the No. 1 and No. 2 absorption towers 4) for desulfurization and gypsum separation. For example, when the No. 1 absorption tower 4 is performing the desulfurization reaction, the No. 2 absorption tower 4 focuses on the separation and discharge of gypsum. Through the alternate operation, it is ensured that the gypsum concentration in each absorption tower 4 is maintained within a relatively ideal range, avoiding system blockage or other problems caused by too high gypsum concentration. The high-chlorine filtrate with a solids content of about 2% is pumped out from the bottom of the gas-liquid separator 62 at the inlet of the dehydration vacuum pump 63 and discharged separately to the wastewater tank 64 as the raw water of the desulfurization wastewater. At the same time, the gypsum slurry at the bottom of the absorption tower 4 is sent to a vacuum belt filter for dehydration treatment to form a gypsum cake with a lower moisture content. By alternately using different vacuum belt filters, the continuous and efficient operation of the equipment can be ensured, and the downtime for maintenance can be reduced.

[0133] The reason why the present application can omit the wastewater cyclone 15 and the plate and frame filter press 16 is mainly due to the system adopting an innovative pre-separation technology and a three-stage physical clarification process, achieving efficient, economical and environmentally friendly solid-liquid separation and sludge treatment. Through the cross-desulfurization gypsum process combined with the vacuum belt dehydration equipment, solid particles in the high-chlorine wastewater can be efficiently removed in the pre-separation stage, and gypsum recovery can be directly carried out, replacing the preliminary solid-liquid separation function of the wastewater cyclone 15. After the water entering the wastewater tank 64 is treated by the vacuum belt dehydration equipment, the solids content is significantly reduced (usually less than 2%), so there is no need for an additional wastewater cyclone 15. Specifically:

[0134] A. Synergistic effect of key equipment

[0135] The vacuum belt kit 61 for gypsum dehydration: Efficiently removes the moisture in the gypsum slurry to form a gypsum cake with a lower moisture content (usually less than 12%). These gypsum cakes can be directly used for building material production or other industrial uses, realizing the maximum utilization of resources.

[0136] The gas-liquid separator 62: Effectively separates air and liquid, prevents the vacuum pump from inhaling moisture, protects the equipment from damage, and ensures the stability and reliability of the dehydration process.

[0137] The dehydration vacuum pump 63: Provides the necessary negative pressure to ensure the smooth progress of the dehydration process, thereby ensuring the efficient operation of the vacuum belt kit 61 for gypsum dehydration.

[0138] The wastewater tank 64: Stores the preliminarily treated wastewater with a low solids content, prepares for further clarification treatment, and ensures the more stable and reliable water quality of the subsequent treatment steps.

[0139] B. Design of the three-stage sedimentation clarifier 14

[0140] The three - stage sedimentation clarifier 14 gradually treats the suspended solids in the wastewater in stages, purifying them step by step from large particles to fine particles, ensuring the quality of the final effluent and reducing the sludge generation at the same time. The primary clarifier 31 mainly treats larger - sized solid substances, discharging the sludge rich in gypsum and sending it to the dehydration equipment for further treatment; the secondary clarifier 32 further removes finer particles; the tertiary clarifier 33 completes the final removal of tiny suspended solids and water quality stabilization treatment.

[0141] C. Intelligent material distribution

[0142] The intelligent design of the gypsum concentration detector 37 and the three - phase switch 38 can automatically adjust the material flow direction according to the real - time monitored gypsum concentration, realizing the maximum utilization of resources and further reducing the demand for the plate - and - frame filter press 16. When the gypsum concentration is high, the sludge is sent to the gypsum dehydration vacuum belt kit 61 for dehydration treatment; when the gypsum concentration is low, the sludge can flow back to the absorption tower 4 or the gypsum overflow tank 7 to supplement the reactive components.

[0143] This solution comprehensively optimizes the desulfurization wastewater treatment process through innovative pre - separated wastewater combined with three - stage clarification technical means, bringing significant environmental and economic benefits:

[0144] Eliminating reagent dependence and avoiding secondary pollution: This system achieves the goal of zero reagent addition in the wastewater treatment process, effectively avoiding the risk of secondary pollution caused by chemical reagent residues, and ensuring that the treated water quality is purer and safer.

[0145] Utilizing gypsum resources and reducing sludge volume: By recycling and reusing the gypsum component in the sludge, not only the generation amount of solid waste is reduced, but also the sludge treatment cost is lowered. Compared with traditional methods, the total sludge volume is reduced by 95%, greatly reducing the environmental burden.

[0146] Significantly reducing operating costs: This solution greatly reduces the reagent cost, and due to the simplified process and improved equipment efficiency, the power consumption, labor cost and sludge disposal cost are also effectively controlled. Overall, the cost of the entire wastewater treatment process is significantly reduced.

[0147] Simplifying the process flow and reducing maintenance workload: The optimized process flow reduces multiple complex steps, reduces the risk of equipment failure, makes the system more automated and easier to operate, thus reducing the need for manual intervention, and the manpower requirement is reduced by 90%.

[0148] Enhancing system reliability and security: Adopting advanced technologies and designs improves the stability and reliability of the system, reduces the frequency of unexpected shutdowns and maintenance, and ensures long - term stable operating performance.

[0149] Significant environmental benefits, reducing environmental pollution: Through the above improvement measures, this solution not only reduces the impact of wastewater discharge on the environment, but also greatly reduces the sludge stacking volume, promotes the green transformation of enterprises, and makes contributions to achieving the sustainable development goals.

[0150] In summary, through the integration of pre-separation and three-stage physical clarification technologies, this solution has successfully solved many problems existing in traditional desulfurized wastewater treatment methods, achieved the goals of efficient, economical and environmental wastewater treatment, and has important application value and promotion potential.

[0151] So far, the embodiments of the present application have been described in detail. To avoid obscuring the concept of the present application, some details well known in the art have not been described. Those skilled in the art can fully understand how to implement the technical solutions disclosed herein based on the above description.

[0152] Although some specific embodiments of the present application have been described in detail by way of examples, those skilled in the art should understand that the above examples are only for illustration and not for limiting the scope of the present application. Those skilled in the art should understand that the above embodiments can be modified or partial technical features can be equivalently replaced without departing from the scope and spirit of the present application. In particular, as long as there is no structural conflict, the technical features mentioned in each embodiment can be combined in any way.

Claims

1. A desulfurized wastewater clarification system, characterized in that, The system includes a pretreatment unit (2) and a clarification unit (3). The pretreatment unit (2) includes an absorption tower (4), a gypsum cyclone (5), a dehydration kit (6), and a gypsum overflow tank (7). The absorption tower (4) is communicated with the gypsum cyclone (5), and the gypsum cyclone (5) can be communicated with the gypsum overflow tank (7) and the dehydration kit (6). The dehydration kit (6) is communicated with the clarification unit (3). The clarification unit (3) includes a multi-stage sedimentation clarifier, and the multi-stage sedimentation clarifier is respectively communicated with the absorption tower (4), the dehydration kit (6), and / or the gypsum overflow tank (7).

2. The desulfurized wastewater clarification system according to claim 1, wherein, The system includes a basic unit (1). The basic unit (1) includes a boiler (8), an electrostatic precipitator (9), and an induced draft fan (10). One end of the boiler (8) is communicated with the electrostatic precipitator (9), and the other end of the electrostatic precipitator (9) is communicated with the absorption tower (4) through the induced draft fan (10). The absorption tower (4) is communicated with a chimney.

3. The desulfurized wastewater clarification system according to claim 1, characterized in that, The lower end of the absorption tower (4) is communicated with the gypsum cyclone (5), the upper end of the gypsum cyclone (5) is communicated with the upper end of the gypsum overflow tank (7), the lower end of the gypsum overflow tank (7) is communicated with the upper end of the absorption tower (4), and the lower end of the gypsum cyclone (5) is communicated with the dehydration kit (6).

4. The desulfurized wastewater clarification system according to claim 3, wherein, The dehydration kit (6) includes a gypsum dehydration vacuum belt kit (61), a gas-water separator (62), a dehydration vacuum pump (63), and a wastewater tank (64). The lower end of the gypsum cyclone (5) is communicated with the gypsum dehydration vacuum belt kit (61), the gypsum dehydration vacuum belt kit (61) is communicated with the gas-water separator (62), one end of the gas-water separator (62) is communicated with the dehydration vacuum pump (63), and the other end of the gas-water separator (62) is communicated with the wastewater tank (64).

5. The desulfurized wastewater clarification system according to claim 4, characterized in that, The gypsum dehydration vacuum belt kit (61) includes a first gypsum dehydration vacuum belt (611) and a second gypsum dehydration vacuum belt (612). The first gypsum dehydration vacuum belt (611) and the second gypsum dehydration vacuum belt (612) are arranged in parallel, and the first gypsum dehydration vacuum belt (611) and the second gypsum dehydration vacuum belt (612) are respectively communicated with the gas-water separator (62).

6. The desulfurized wastewater clarification system according to claim 5, wherein The wastewater tank (62) is communicated with the clarification unit (3). The clarification unit (3) includes a primary clarifier (31), a secondary clarifier (32), a tertiary clarifier (33), and a storage tank (34) that are communicated in sequence from high to low. The wastewater tank (64) is communicated with the primary clarifier (31).

7. The desulfurized wastewater clarification system according to claim 6, wherein The clarification unit (3) further includes a sludge discharge pump (35). One end of the primary clarifier (31) is communicated with the sludge discharge pump (35), and the other end of the sludge discharge pump (35) is respectively communicated with the first gypsum dehydration vacuum belt (611) and the second gypsum dehydration vacuum belt (612).

8. The desulfurized wastewater clarification system according to claim 7, wherein The clarification unit (3) further includes a gypsum concentration detector (37) and a three-phase switch (38). A gypsum concentration detector (37) is provided between the primary clarifier (31) and the sludge discharge pump (35). The gypsum concentration detector (37) is located above the three-phase switch (38) between the primary clarifier (31) and the sludge discharge pump (35) and close to the primary clarifier (31).

9. The desulfurized wastewater clarification system according to claim 7, wherein, The clarification unit (3) further includes a sump (36). The primary clarifier (31) can also communicate with the absorption tower (4), and / or the primary clarifier (31) communicates with the gypsum overflow tank (7) through the sump (36).

10. The desulfurized wastewater clarification system according to claim 9, characterized in that, The secondary clarifier (32) communicates with the absorption tower (4), or the secondary clarifier (32) communicates with the gypsum overflow tank (7) through the sump (36).

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