Evaporative crystallization treatment device for desulfurization wastewater of power plant

Abstract

The utility model relates to an evaporative crystallization treatment device for desulfurization wastewater of a power plant, which belongs to the technical field of wastewater treatment of the power plant, comprises a triple-effect forced circulation evaporation device, a plate-and-frame filter press, a distilled water collection system, a preheater, a condenser, a mother liquor tank and a thickener, and is characterized by also comprising a liquid phase storage tank, the liquid phase storage tank is used for storing liquid filtered by the plate-and-frame filter press, a water outlet of the triple-effect forced circulation evaporation device is connected with a water inlet of the plate-and-frame filter press through a pipeline, and a liquid outlet of the plate-and-frame filter press is connected with an inlet of the liquid phase storage tank through a pipeline. According to the evaporative crystallization treatment device for the desulfurization wastewater of the power plant, the problem of scaling of calcium and magnesium ions is effectively avoided, the heat transfer efficiency of the evaporator and the wastewater treatment effect are improved, and meanwhile, the purity of crystallized salts reaches the industrial grade standard through optimal control over the crystallization process, so that the crystallized salts can be directly recycled and reused, and the economic benefit is increased. Therefore, efficient utilization of resources and environmental protection are realized.

Description

Technical Field

[0001] The utility model relates to the technical field of power plant wastewater treatment, and specifically relates to an evaporation crystallization treatment device for desulfurization wastewater in power plants. Background Technique

[0002] At present, in the field of environmental protection, the treatment of desulfurization wastewater in power plants has become a crucial topic.

[0003] Traditional methods for treating desulfurization wastewater in power plants usually include chemical precipitation, membrane separation, evaporation crystallization, etc. However, when treating wastewater with high calcium and magnesium ion content, these methods often face problems such as scaling, equipment blockage, and decreased heat transfer efficiency. Especially when using the evaporation crystallization technology, due to the presence of calcium and magnesium ions, scaling easily forms on the surface of the equipment, resulting in equipment blockage, thereby affecting the heat transfer efficiency and increasing the operating cost.

[0004] In response to this problem, it is of great practical significance to develop an efficient and reliable evaporation crystallization treatment device for desulfurization wastewater in power plants. Such a device needs to adopt advanced technical means to overcome the influence brought by calcium and magnesium ion scaling, improve the heat transfer efficiency, reduce equipment blockage, and thus achieve the efficient treatment of desulfurization wastewater in power plants.

[0005] The core technologies of this device may include using special materials and surface treatment technologies to prevent calcium and magnesium ions from scaling on the surface of the equipment; optimizing the hydrodynamic design to improve the heat transfer efficiency; adopting an intelligent control system to monitor and control the parameters in the treatment process in real time to ensure the stable operation of the equipment.

[0006] In short, the research and application of the evaporation crystallization treatment device for desulfurization wastewater in power plants are of great significance for solving the current problems in the treatment of desulfurization wastewater in power plants, improving the utilization efficiency of water resources, and protecting the ecological environment.

[0007] Traditional evaporation crystallization technology has some serious defects in the treatment of desulfurization wastewater in power plants. Due to the high content of calcium and magnesium ions in the desulfurization wastewater of power plants, these ions are prone to crystallize and precipitate during the evaporation crystallization process, forming calcium and magnesium scale. These calcium and magnesium scales will gradually accumulate on the surface and inside of the equipment, resulting in a reduction in the effective heat transfer area of the equipment and a significant decrease in the heat transfer efficiency. This will not only increase the operating cost of the equipment but also affect the service life of the equipment.

[0008] In addition, it is difficult for traditional evaporation crystallization technology to achieve the resource recycling of salts. Due to the presence of calcium and magnesium scale, the purity of the salts obtained during the evaporation crystallization process is relatively low, making it difficult to meet the quality standards of industrial salts. This means that these salts cannot be directly reused as industrial raw materials and can only be treated as solid waste. This not only increases the treatment cost but also wastes resources.

[0009] In addition, the formation of calcium and magnesium scale will also cause the equipment to stop for cleaning frequently, seriously affecting the production efficiency. A large amount of chemical agents and water are needed during the cleaning process, which not only increases the production cost but also causes certain pollution to the environment.

[0010] To sum up, the traditional evaporation crystallization technology has many disadvantages when treating the desulfurization wastewater of power plants. These disadvantages not only increase the operation cost and maintenance difficulty of the equipment but also seriously affect the resource reuse efficiency. Therefore, it is an urgent need in the current environmental protection field to develop a more advanced and efficient wastewater treatment technology to overcome these disadvantages. Summary of the Invention

[0011] In view of the deficiencies of the prior art, the present utility model provides an evaporation crystallization treatment device for desulfurization wastewater of power plants, which has the advantages of effectively avoiding the scaling problem of calcium and magnesium ions, improving the heat transfer efficiency of the evaporator and the wastewater treatment effect, and enabling the purity of the crystalline salts to reach the industrial standard for direct resource reuse, etc., and solves the problems of increased equipment operation cost, shortened service life, difficulty in realizing the resource reuse of salts, and affecting production efficiency and environmental pollution when the existing traditional evaporation crystallization technology is used to treat the desulfurization wastewater of power plants.

[0012] To sum up, the present utility model provides the following technical solution: An evaporation crystallization treatment device for desulfurization wastewater of power plants, including a triple-effect forced circulation evaporation device, a plate and frame filter press, a distilled water collection system, a preheater, a condenser, a mother liquor tank and a thickener, characterized in that it further includes a liquid-phase storage tank, the liquid-phase storage tank is used for storing the liquid filtered by the plate and frame filter press, the water outlet of the triple-effect forced circulation evaporation device is connected to the water inlet of the plate and frame filter press through a pipeline, the liquid outlet of the plate and frame filter press is connected to the inlet of the liquid-phase storage tank through a pipeline, the outlet of the liquid-phase storage tank is connected to the inlet of the salt recovery device through a pipeline, the steam outlet of the triple-effect forced circulation evaporation device is connected to the steam inlet of the condenser through a pipeline, and the water outlet of the condenser is connected to the inlet of the distilled water collection system through a pipeline.

[0013] Further, the water outlet of the preheater is connected to the water inlet of the triple-effect forced circulation evaporation device through a pipeline.

[0014] By adopting the above technical solution, in this link, the preheater plays a key role. It can preheat the water and raise the water temperature. After the preheated water enters the triple-effect forced circulation evaporation device, it can reach the evaporation temperature faster, improving the evaporation efficiency. At the same time, this connection method also ensures the continuous operation of the entire device and the coordinated work of each structure, thus realizing the efficient treatment of the desulfurization wastewater of power plants.

[0015] Furthermore, the distilled water collection system includes a steam-water separator and a condensate balance tank.

[0016] By adopting the above technical solution, inside the steam-water separator, through the actions of centrifugal force, gravity, etc., the moisture is separated from the steam. The separated steam is discharged from the top of the steam-water separator, while the moisture is discharged from the bottom. In this way, the effective separation of steam and water is achieved, providing a basis for subsequent treatment. The condensate balance tank plays a role in balancing and storing condensate. The moisture separated by the steam-water separator enters the condensate balance tank in the form of condensate. Inside the condensate balance tank, by controlling the liquid level and other means, the storage and balance of condensate are realized. In this way, the stable operation of the entire system can be ensured, and at the same time, a stable water source is provided for subsequent treatment. During the actual operation process, the steam-water separator and the condensate balance tank cooperate with each other to jointly complete the collection and treatment of distilled water.

[0017] Furthermore, the triple-effect forced circulation evaporation device includes a triple-effect evaporator and a triple-effect separator, and the triple-effect evaporator is an MVR evaporator.

[0018] By adopting the above technical solution, the wastewater enters the MVR evaporator, where it exchanges heat with the steam. The wastewater is heated and evaporated, and the generated steam is compressed and then enters the evaporator again as a heating medium to continue heating the wastewater. In this way, through the recycling of steam, the energy utilization efficiency is greatly improved, and the energy consumption is reduced. At the same time, the wastewater is continuously evaporated and concentrated in the evaporator, and the concentration gradually increases. When the wastewater reaches a certain concentration, it enters the triple-effect separator for separation. In the triple-effect separator, the steam and the concentrated liquid are separated. The steam enters the next-effect evaporator to continue heating the wastewater, while the concentrated liquid is discharged out of the system. Through the mutual cooperation of the triple-effect evaporator and the triple-effect separator, the efficient evaporation and concentration treatment of the wastewater are realized, and the treatment efficiency and quality of the wastewater are improved.

[0019] Furthermore, a circulation pump is fixedly installed inside the triple-effect forced circulation evaporation device.

[0020] By adopting the above technical solution, the main function of the circulation pump is to promote the liquid to circulate inside the device. Through the operation of the circulation pump, the liquid can continuously circulate between the evaporator and the separator, ensuring sufficient contact between the liquid and the heating medium and improving the heat transfer efficiency.

[0021] Furthermore, a salt recovery device is provided after the plate and frame filter press. The salt recovery device includes a centrifuge and a drying device; the liquid outlet of the centrifuge in the salt recovery device is connected to the inlet of the drying device through a pipeline. The thickener is connected to the centrifuge through a pipeline and is also connected to the condenser and the distilled water collection system through a pipeline.

[0022] By adopting the above technical solution, a centrifuge is used to separate solids and liquids in the filtrate of a plate and frame filter press to obtain solid salts with a relatively high salt content. A drying device is used to dry the solid salts obtained by the centrifuge to remove the moisture therein, obtaining dried solid salts. After the plate and frame filter press, a salt recovery device is also provided. The device includes a centrifuge and a drying device. Among them, the liquid outlet of the centrifuge is connected to the inlet of the drying device through a pipeline, and the thickener is connected to the centrifuge through a pipeline and is also connected to a condenser and a distilled water collection system through a pipeline.

[0023] Furthermore, the mother liquor tank is connected to the centrifuge through a pipeline and is also connected to a condensate balance tank through a pipeline.

[0024] By adopting the above technical solution, in addition to the connection methods described above, the mother liquor tank is also connected to the centrifuge through a pipeline and is also connected to the condensate balance tank through a pipeline. Such a connection method enables the liquid in the mother liquor tank to be transported to the centrifuge for further processing, such as centrifugal separation. At the same time, the mother liquor tank is also connected to the condensate balance tank. This connection may be used to balance the liquid flow or pressure in the system, ensuring the stability of the entire process flow. This interconnected design enables each structure to work together to achieve a more efficient production process and resource utilization. In practical applications, the specific purpose and function of this connection method may vary according to the specific process flow and requirements.

[0025] Furthermore, the temperature of the triple-effect forced circulation evaporation device is controlled at 50°C to 75°C.

[0026] By adopting the above technical solution, such temperature control is crucial for the stability and efficiency of the evaporation process. By controlling the temperature within this range, the smooth progress of the evaporation process can be ensured, while minimizing energy consumption and equipment wear.

[0027] Compared with the prior art, the present utility model provides a device for evaporative crystallization treatment of desulfurized wastewater in a power plant, having the following beneficial effects:

[0028] This device for evaporative crystallization treatment of desulfurized wastewater in a power plant, through the coordinated use of a plate and frame filter press, a distilled water collection system, a circulation pump, a salt recovery device, an MVR evaporator, a preheater, a condenser, a mother liquor tank, a thickener, and a liquid phase storage tank on the triple-effect forced circulation evaporation device, effectively avoids the problem of calcium and magnesium ion scaling, improves the heat transfer efficiency of the evaporator and the wastewater treatment effect. At the same time, through the optimized control of the crystallization process, the purity of the crystallized salts reaches the industrial grade standard and can be directly reused for resource utilization, thereby achieving the efficient utilization of resources and environmental protection. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a schematic structural view of the present utility model;

[0030] Figure 2 is Figure 1 a partial enlarged view of part A in

[0031] Explanation of reference numerals:

[0032] 100, triple-effect forced circulation evaporation device; 2, plate and frame filter press; 300, distilled water collection system; 301, steam-water separator; 302, condensate balance tank; 4, circulation pump; 5, salt recovery device; 501, centrifuge; 502, drying equipment; 6, MVR evaporator; 7, preheater; 8, condenser; 9, mother liquor tank; 10, thickener; 11, liquid phase storage tank. Specific embodiments

[0033] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present utility model.

[0034] Please refer to Figures 1 to 2 , the present utility model provides a technical solution: a desulfurized waste water evaporation and crystallization treatment device for power plants, including a triple-effect forced circulation evaporation device 100, a plate and frame filter press 2, a distilled water collection system 300, a preheater 7, a condenser 8, a mother liquor tank 9 and a thickener 10, and further including a liquid phase storage tank 11. The liquid phase storage tank 11 is used to store the liquid filtered by the plate and frame filter press 2. The water outlet of the triple-effect forced circulation evaporation device 100 is connected to the water inlet of the plate and frame filter press 2 through a pipeline. The liquid outlet of the plate and frame filter press 2 is connected to the inlet of the liquid phase storage tank 11 through a pipeline. The outlet of the liquid phase storage tank 11 is connected to the inlet of the salt recovery device 5 through a pipeline. The steam outlet of the triple-effect forced circulation evaporation device 100 is connected to the steam inlet of the condenser 8 through a pipeline. The water outlet of the condenser 8 is connected to the inlet of the distilled water collection system 300 through a pipeline.

[0035] During the operation of the device, the water outlet of the triple-effect forced circulation evaporation device 100 is closely connected to the water inlet of the plate and frame filter press 2 through a specific pipeline, so that the treated water can smoothly flow into the plate and frame filter press 2. The liquid outlet of the plate and frame filter press 2 is also connected to the inlet of the liquid phase storage tank 11 through a pipeline, thus realizing the efficient storage of the liquid. The outlet of the liquid phase storage tank 11 is connected to the inlet of the salt recovery device 5 through a pipeline, laying a foundation for the subsequent salt recovery work.

[0036] Meanwhile, the steam outlet of the triple-effect forced circulation evaporation device 100 is connected to the steam inlet of the condenser 8 through a pipeline, enabling the steam to be cooled and condensed in the condenser 8. The water outlet of the condenser 8 is connected to the inlet of the distilled water collection system 300 through a pipeline, ensuring the effective collection of distilled water.

[0037] In this entire set of systems, each structure cooperates with each other in harmony. The triple-effect forced circulation evaporation device 100 converts the water in the wastewater into steam through efficient evaporation; the plate and frame filter press 2 filters the liquid to remove impurities and solid particles; the liquid-phase storage tank 11 provides a stable storage space; the salt recovery device 5 realizes the recovery and utilization of salts; the condenser 8 and the distilled water collection system 300 ensure the cooling of steam and the collection of distilled water. Through the mutual cooperation of these structures, this device can efficiently treat the desulfurization wastewater of power plants, achieving the dual purposes of environmental protection and resource recovery.

[0038] As Figure 1 and Figure 2 shown, in this embodiment, by adopting the evaporation and crystallization treatment device for desulfurization wastewater of power plants of the present utility model, the desulfurization wastewater of power plants has been effectively treated and utilized. It not only avoids the calcium and magnesium ion scaling problem existing in traditional evaporation and crystallization technologies, improves the heat transfer efficiency of the evaporator and the wastewater treatment effect, but also realizes the resource recycling of salts and the up-to-standard discharge of distilled water. Therefore, this device has remarkable environmental and economic benefits.

[0039] It should be noted that the water outlet of the preheater 7 is connected to the water inlet of the triple-effect forced circulation evaporation device 100 through a pipeline. In the entire device, the water outlet of the preheater 7 is precisely connected to the water inlet of the triple-effect forced circulation evaporation device 100 through a pipeline. This connection method enables the water heated by the preheater to flow smoothly into the triple-effect forced circulation evaporation device. In this link, the preheater 7 plays a key role. It can preheat the water and raise the water temperature. After the preheated water enters the triple-effect forced circulation evaporation device 100, it can reach the evaporation temperature faster, improving the evaporation efficiency. At the same time, this connection method also ensures the continuous operation of the entire device, ensuring the coordinated work among various structures, thereby realizing the efficient treatment of the desulfurization wastewater of power plants.

[0040] It can be understood that the distilled water collection system 300 includes a steam-water separator 301 and a condensate balance tank 302. In this system, the distilled water collection system 300 plays an important role. It mainly consists of two key parts, namely the steam-water separator 301 and the condensate balance tank 302. The function of the steam-water separator 301 is to separate steam and water. Specifically, it introduces the steam containing water into it through a special structure and working principle. Inside the steam-water separator, through the action of centrifugal force, gravity, etc., the water is separated from the steam. The separated steam is discharged from the top of the steam-water separator, while the water is discharged from the bottom. In this way, the effective separation of steam and water is achieved, providing a basis for subsequent processing. The condensate balance tank 302 plays the role of balancing and storing condensate. The water separated by the steam-water separator enters the condensate balance tank 302 in the form of condensate. Inside the condensate balance tank, by controlling the liquid level and other methods, the storage and balance of condensate are realized. In this way, the stable operation of the entire system can be ensured, and at the same time, a stable water source is provided for subsequent processing. During the actual operation process, the steam-water separator 301 and the condensate balance tank 302 cooperate with each other to jointly complete the collection and processing of distilled water.

[0041] In addition, the triple-effect forced circulation evaporation device 100 includes a triple-effect evaporator and a triple-effect separator. The triple-effect evaporator is an MVR evaporator 6. In this device, the triple-effect forced circulation evaporation device 100 consists of a triple-effect evaporator and a triple-effect separator. Among them, the triple-effect evaporator adopts the MVR evaporator 6. The MVR evaporator 6 is a highly efficient evaporation device. It realizes the efficient utilization of energy and the concentration treatment of wastewater by using the compression and reuse of steam. In the triple-effect forced circulation evaporation device 100, the MVR evaporator 6 and the triple-effect separator cooperate with each other to jointly complete the evaporation and concentration process of wastewater. First, the wastewater enters the MVR evaporator 6, and heat exchange occurs between the wastewater and the steam in the evaporator. The wastewater is heated and evaporated, and the generated steam is compressed and then enters the evaporator again as a heating medium to continue heating the wastewater. In this way, through the recycling of steam, the utilization efficiency of energy is greatly improved, and the energy consumption is reduced. At the same time, the wastewater is continuously evaporated and concentrated in the evaporator, and the concentration gradually increases. When the wastewater reaches a certain concentration, it enters the triple-effect separator for separation. In the triple-effect separator, the steam and the concentrated liquid are separated. The steam enters the next-effect evaporator to continue heating the wastewater, while the concentrated liquid is discharged out of the system. Through the mutual cooperation of the triple-effect evaporator and the triple-effect separator, the efficient evaporation and concentration treatment of wastewater are realized, and the treatment efficiency and quality of wastewater are improved.

[0042] In this embodiment, a circulation pump 4 is provided inside the triple-effect forced circulation evaporation device 100. Inside the triple-effect forced circulation evaporation device 100, a circulation pump 4 is carefully arranged. This circulation pump 4 plays a crucial role in the entire device. It cooperates with other structures to jointly achieve an efficient evaporation process.

[0043] The main function of the circulation pump 4 is to drive the liquid to circulate inside the device. Through the operation of the circulation pump 4, the liquid can continuously circulate between the evaporator and the separator, ensuring sufficient contact between the liquid and the heating medium and improving the heat transfer efficiency.

[0044] Specifically, when the liquid enters the triple-effect forced circulation evaporation device 100, the circulation pump 4 will suck it in and pressurize it, making it enter the evaporator at a relatively high flow rate. In the evaporator, the liquid exchanges heat with the heating medium, and the moisture in it is evaporated to form steam. The steam then enters the separator. In the separator, the steam is separated from the liquid, and the liquid returns to the evaporator through the circulation pump 4 for cyclic evaporation.

[0045] The operating speed and flow rate of the circulation pump 4 can be adjusted according to actual needs to adapt to different process requirements. At the same time, in order to ensure the normal operation of the circulation pump 4, corresponding control systems and protection devices, such as frequency converters, overload protection devices, etc., are also required.

[0046] In short, the circulation pump 4 is an indispensable component in the triple-effect forced circulation evaporation device 100. It cooperates with other structures to jointly achieve an efficient and stable evaporation process, providing important support for industrial production.

[0047] It should also be noted that a salt recovery device 5 is provided after the plate and frame filter press 2. The salt recovery device 5 includes a centrifuge 501 and a drying device 502; the liquid outlet of the centrifuge 501 in the salt recovery device 5 is connected to the inlet of the drying device 502 through a pipeline. The thickener 10 is connected to the centrifuge 501 through a pipeline and is also connected to the condenser 8 and the distilled water collection system 300 through a pipeline. The centrifuge 501 is used to separate the solids and liquids in the filtrate of the plate and frame filter press 2 to obtain solid salts with a relatively high salt content. The drying device 502 is used to dry the solid salts obtained by the centrifuge 501 to remove the moisture in them and obtain dry solid salts. After the plate and frame filter press 2, a salt recovery device 5 is also provided. This device includes a centrifuge 501 and a drying device 502. Among them, the liquid outlet of the centrifuge 501 is connected to the inlet of the drying device 502 through a pipeline, while the thickener 10 is connected to the centrifuge 501 through a pipeline and is also connected to the condenser 8 and the distilled water collection system 300 through a pipeline.

[0048] The main function of the centrifuge 501 is to separate the solids and liquids in the filtrate of the plate and frame filter press 2, so as to obtain solid salts with a relatively high salt content. In this process, the centrifuge 501 uses the action of centrifugal force to throw the solid particles in the filtrate onto the inner wall of the centrifuge, forming a solid salt layer, while the liquid is discharged through the outlet of the centrifuge.

[0049] The drying equipment 502 is used to dry the solid salts obtained by the centrifuge 501, remove the moisture therein, and obtain dry solid salts. During the drying process, the drying equipment 502 evaporates the moisture in the solid salts through heating, ventilation and other means, so as to achieve the purpose of drying.

[0050] In summary, the centrifuge 501 and the drying equipment 502 in the salt recovery device 5 cooperate with each other to jointly complete the recovery and treatment of the salts in the filtrate of the plate and frame filter press 2. In this way, the salts in the filtrate can be effectively recovered, resource waste can be reduced, and environmental pollution can also be reduced.

[0051] It should be further noted that the mother liquor tank 9 is connected to the centrifuge 501 through a pipeline and is also connected to the condensate balance tank 302 through a pipeline. In addition to the above-described connection method, the mother liquor tank 9 is also connected to the centrifuge 501 through a pipeline and is also connected to the condensate balance tank 302 through a pipeline in the same way. Such a connection method enables the liquid in the mother liquor tank 9 to be transported to the centrifuge 501 for further treatment, such as centrifugal separation. At the same time, the mother liquor tank 9 is also connected to the condensate balance tank 302. This connection may be used to balance the liquid flow or pressure in the system to ensure the stability of the entire process flow. This interconnected design enables each structure to work together to achieve a more efficient production process and resource utilization. In practical applications, the specific purpose and function of this connection method may vary according to the specific process flow and requirements.

[0052] In addition, it should be noted that the triple-effect forced circulation evaporation device 100 controls the evaporation temperature at 50°C to 75°C. This temperature control is crucial for the stability and efficiency of the evaporation process. By controlling the temperature within this range, the smooth progress of the evaporation process can be ensured, while minimizing energy consumption and equipment wear.

[0053] In addition, the triple-effect forced circulation evaporation device 100 also cooperates with other structures to jointly achieve the efficient operation of the entire system. For example, it cooperates with the preheater 1 to preheat the material to be processed to an appropriate temperature, thereby improving the evaporation efficiency.

[0054] At the same time, the triple-effect forced circulation evaporation device 100 also cooperates with the condenser 8 to condense the steam generated during the evaporation process into a liquid, thereby achieving the concentration and recovery of the material.

[0055] In summary, the precise temperature control of the triple-effect forced circulation evaporation device 100 and its interaction with other structures enable the entire system to operate efficiently and stably, providing reliable support for industrial production.

[0056] The working principle of the above embodiments is as follows:

[0057] During the desulfurization wastewater treatment process in a certain power plant, in actual operation, the power plant desulfurization wastewater is first sent to the preheater 7 for preheating, and then enters the triple-effect forced circulation evaporation device 100 for evaporation crystallization. Due to the special design of the triple-effect forced circulation evaporation device 100, the evaporation temperature can be stabilized below 75°C, effectively avoiding the scaling problem of calcium and magnesium ions.

[0058] During the evaporation process, the water in the wastewater gradually evaporates, and the salt substances gradually concentrate. When the concentration of the salt substances reaches a certain level, crystallization will occur. These crystals will be filtered through the plate and frame filter press 2 to separate the solid salts from the liquid.

[0059] The filtered liquid enters the liquid-phase storage tank 11 for storage, and then is further processed through the salt recovery device 5. The salt recovery device 5 includes a centrifuge 501 and a drying device 502, which can separate and dry the solid salts in the liquid to obtain dry solid salts.

[0060] The generated steam is cooled by the condenser 8 and converted into distilled water. The distilled water enters the distilled water collection system 300 through a pipeline for collection and treatment, reducing its conductivity to below 50 to meet the discharge standard.

[0061] The mother liquor tank 9 is used to collect the concentrated mother liquor from the triple-effect forced circulation evaporator 1, and then is connected to the centrifuge 501 through a pipeline for solid-liquid separation. The separated liquid then enters the condensate balance tank 302 for treatment or reuse.

[0062] Compared with the prior art: For the desulfurized waste water evaporation and crystallization treatment device of the power plant, through the coordinated use among the plate and frame filter press 2, distilled water collection system 300, circulation pump 4, salt recovery device 5, MVR evaporator 6, preheater 7, condenser 8, mother liquor tank 9, thickener 10 and liquid phase storage tank 11 on the triple-effect forced circulation evaporation device 100, the problem of calcium and magnesium ion scaling is effectively avoided, the heat transfer efficiency of the evaporator and the waste water treatment effect are improved. At the same time, through the optimized control of the crystallization process, the purity of the crystallized salts reaches the industrial grade standard and can be directly recycled resourcefully, thus realizing the efficient utilization of resources and environmental protection, and solving the problems existing in the treatment of desulfurized waste water of power plants by the existing traditional evaporation and crystallization technology, such as the increase of equipment operation cost, the shortening of service life, the difficulty in realizing the resourceful recycling of salts, the influence on production efficiency and environmental pollution.

[0063] The electrical components mentioned in the text are all electrically connected to the main controller and the power supply. The main controller can be a conventional known device such as a computer for control, and the existing publicly disclosed power connection technology and the provision of the power supply also belong to the common knowledge in the field, so they will not be elaborated in detail in this application.

Claims

1. A power plant desulfurization wastewater evaporation and crystallization treatment device, comprising a three-effect forced circulation evaporation device (100), a plate and frame filter press (2), a distilled water collection system (300), a preheater (7), a condenser (8), a mother liquor tank (9) and a thickener (10), characterized in that: The system further comprises a liquid phase storage tank (11), wherein the liquid phase storage tank (11) is used to store liquid filtered by the plate and frame filter press (2); the water outlet of the triple-effect forced circulation evaporation device (100) is connected to the water inlet of the plate and frame filter press (2) via a pipeline; the liquid outlet of the plate and frame filter press (2) is connected to the inlet of the liquid phase storage tank (11) via a pipeline; the outlet of the liquid phase storage tank (11) is connected to the inlet of the salt recovery device (5) via a pipeline; the steam outlet of the triple-effect forced circulation evaporation device (100) is connected to the steam inlet of the condenser (8) via a pipeline; and the water outlet of the condenser (8) is connected to the inlet of the distilled water collection system (300) via a pipeline.

2. The power plant desulfurization wastewater evaporation and crystallization treatment device according to claim 1 is characterized in that: The water outlet of the preheater (7) is connected to the water inlet of the triple-effect forced circulation evaporation device (100) through a pipeline.

3. The power plant desulfurization wastewater evaporation and crystallization treatment device according to claim 1 is characterized in that: The distilled water collection system (300) comprises a steam-water separator (301) and a condensed water balance tank (302).

4. The power plant desulfurization wastewater evaporation and crystallization treatment device according to claim 1 is characterized in that: The triple-effect forced circulation evaporation device (100) comprises a triple-effect evaporator and a triple-effect separator, and the triple-effect evaporator is an MVR evaporator (6).

5. The power plant desulfurization wastewater evaporation and crystallization treatment device according to claim 4 is characterized in that: A circulation pump (4) is fixedly installed inside the triple-effect forced circulation evaporation device (100).

6. The power plant desulfurization wastewater evaporation and crystallization treatment device according to claim 1 is characterized in that: A salt recovery device (5) is provided after the plate and frame filter press (2), and the salt recovery device (5) comprises a centrifuge (501) and a drying device (502); the liquid outlet of the centrifuge (501) in the salt recovery device (5) is connected to the inlet of the drying device (502) through a pipeline, and the thickener (10) is connected to the centrifuge (501) through a pipeline, and is also connected to a condenser (8) and a distilled water collection system (300) through a pipeline.

7. The power plant desulfurization wastewater evaporation and crystallization treatment device according to claim 1 is characterized in that: The mother liquid tank (9) is connected to the centrifuge (501) via a pipeline, and is also connected to the condensate balance tank (302) via a pipeline.

8. The power plant desulfurization wastewater evaporation and crystallization treatment device according to claim 1, characterized in that: The triple-effect forced circulation evaporation device (100) controls the evaporation temperature to be between 50°C and 75°C.

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